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Remediation solutions Issue XXVII Winter 2017

Winners Guide


Brought to you by: ltd

Upcoming Events 2018 Executive Briefing Webinar:

Brownfield Land Scotland 2018

Development on and Near Closed Landfills

7 February 2018, Edinburgh

23 May 2018

Executive Briefing Webinar:

Executive Briefing Webinar:

Vapour Intrusion: Monitoring, Assessment and Remediation 21 February 2018

Ground Gas 2018 1 March 2018, London

Courting Wisdom - Lessons from Recent Judgments, Appeals and Debates 13 June 2018

EA Business Summit 2018 20 June 2018, London

Executive Briefing Webinar:

High Resolution Ground Characterisation for Better CSMs

Site Investigation 2018 28 June 2018, London

21 March 2018

Groundwater 2018 22 March 2018, London

Brownfield and Contaminated Land 2018 19 April 2018, Belfast

Brownfield Risk & Remediation 2018 27 September 2018, London

Brownfield Briefing Awards 2018 27 September 2018, London

Executive Briefing Webinar:

New Remediation Technologies, Including Nanoremediation 25 April 2018

Brownfield Land Wales 2018 4 October 2018, Cardiff

For more information email sales@environment-analyst.com or call +44 (0)20 3637 2191


contents / editorial | 3

Contents

From the editor

Brownfield Briefing Awards 2017 Winners

4 6 8 10 12 14 16 19 21 23 25 27 29 31 33 44 45

Project Thistle – Ex Situ Remediation on an Operational Pharmaceutical Site

In-Situ Thermal Remediation Enhancement of a Dual Phase Extraction System Sustainable Low Temperature In-Situ Thermal Remediation of Pesticides Chapelcross Magnox

Chapelcross site - assessment of groundwater contamination arising from past use of solvents Coed Darcy

”Making Places” – National School Photography Competition

Leeds College of Arts

Light Non Aqueous Phase Liquid (LNAPL) Automatous Monitoring System Former House Estate, South East London

Waters Keep - Goscote Lane Corridor Regeneration Area, Walsall

Drainage Network - Glan Llyn, Former Llanwern Steelworks, Newport, South Wales River Ewelme, former engine manufacturing works, Dursley, Gloucestershire Silverton Mill, Devon

Best Young Brownfield Professional

UK Remediation Consultants

UK Remediation Contractors

Entries to and winners of the annual Brownfield Briefing Awards provide an important weathervane indicating trends and directions within the industry. Notable this year were the number of asbestos remediation projects, the continued importance of carbon reduction and energy efficiency along with material management plans, and the significance of supporting treatment trains in single discipline entries. But the most dramatic change is how IT and data capture and management is impacting the industry. On asbestos, McAuliffe, Higgins and the Notting Hill Housing project was one of the first to us the JIWG decision support tool published as part of the CL:AIRE CAR-SOIL guidance document. It use in concert with a Materials Management Plan was also produced following the Definition of Waste Code of Practice. In the WYG Group, Sanctus and Leeds College of Art project which won Best Use of Materials on a Project, 9.7t of asbestos contaminated waste was disposed of and 97.4% of material was re-used on-site (excluding asbestos waste). In both of these data management was at the heart of the projects. At Leeds, the uploading of site data to a shared cloud server on a daily basis to aid real time checking was very effective. In the Notting Hill Housing project 3D GPS-enabled plant was integrated with 3D AutoCad model. The system could record the as-built data as the excavation progressed, removing the need for repeated surveys and was monitored from a live internet 3D site link. The integration of Building Information Management with remediation technology is truly disruptive. In the McAuliffe project the operators were freed from the most routine functions and taking on more of an engineering and remediation role. They had to interpret the drawings on their cab displays, understand layered information and remediation management, record as-built information and code each survey point correctly. By using the system, project time was cut by 40%, and with less personnel on site, the risk of accidents was far less. Data management was noteworthy in other projects including ERM’s pesticide remediation where thermal modelling and bench testing which reduced temperatures by 80% and Arcadis’s 3D geological model at Chapelcross. On a final note this was the thirteenth annual awards and several winners came from regeneration projects started in the noughties, including Waters Keep in Walsall, Coed Darcy and the former Llanwern steelworks in Wales – a reminder in the brave new shiny IT world, the industry has roots in longevity. Ian Grant Managing Editor: Ian Grant Production: Petya Grozeva Deputy Editor: Eoin Redahan Sales: Faye Heslin-Jones, Yulia Stuart Printer: Premier Print Group 25-31 Violet Road, London, E3 3QQ Published by Environment Analyst, London NW10 5LJ Tel: 020 8969 1008 Email: customerservice@brownfieldbriefing.com © Environment Analyst 2016. All rights reserved. No material may be reproduced in whole or in part without the permission of the copyright holders. www.brownfielfbriefing.com


Best use of a Combination of Remediation Techniques

4 | Brownfield Briefing Awards 2017 WINNER

Project Thistle – Ex Situ Remediation on an Operational Pharmaceutical Site ORGANISATIONS

AECOM and HBR Limited For this project, AECOM and HBR Ltd used a combination of remediation techniques to treat a wide variety of chlorinated hydrocarbons in challenging geological conditions, while working on an operational top tier COMAH pharmaceutical facility. Remediation was undertaken to treat contaminated soils, avoid off-site disposal, minimise the client’s carbon footprint, and avoid importing quarried recycled material. About 11,500m³ of impacted soil was successfully treated on-site using a combination of physical, biological, and chemical ex-situ techniques that included anaerobic bioremediation, aerobic bioremediation, and chemical oxidation. All of the excavated and treated soil was reused on-site to provide a flexible development platform in the treated areas for potential future site expansion. The works were undertaken on a voluntary basis to meet the client’s corporate social responsibility policy and mitigate potential future ongoing liabilities associated with future site development plans. AECOM acted as Principal designer and principal contractor under the Construction Design and Management Regulations 2015 and deployed the site under its environmental permit. HBR acted as the specialist remediation design and build sub-contractor.

Getting underway A detailed intrusive investigation of the contaminated areas using Membrane Interface Probes (MIP) and boreholes resulted in the delineation of a well-defined plume of chlorinated hydrocarbons including 1-3 dichlorobenzene (1-3DCB), 1-2, Dichloroethane (1-2DCA), dichloromethane (DCA), chloroform, and vinyl chloride with concentrations up to 10,000,000µg/kg in shallow soils and perched groundwater, which are associated with historical manufacturing operations. Detailed quantitative risk assessment demonstrated that concentrations of concerning compounds would potentially cause an unacceptable risk to human health for a commercial end use. AECOM and HBR provided a remediation strategy that offered a flexible development

area to support future plant expansion, while: n using site investigation data and screening techniques to segregate material that had not been impacted to avoid unnecessary work n reducing the concentrations of compounds of concern such that they no longer posed an unacceptable risk to human health for commercial end use n using a combination of an innovative treatment train approach to target the complex mix of compounds of concern in challenging soil conditions (firm clay) n implementing a robust materials management plan in which the bases and faces of excavations were validated to ensure that contamination had been excavated n frequently sampling of the material to deduce which material had passed the physical/biological treatment and which required further chemical treatment further along the treatment train n designing the remediation processes so that the activities did not generate noise, vibration, odour, dust, and volatile organic compounds, especially given that they were working on an active pharmaceutical site) n ensuring chemical treatment was contained to avoid impacting the soil pH of the neighbouring SSI n improving the geotechnical characteristics soil post remediation for

replacement, and reusing 100% of the excavated material.

Implementing best practice The site challenge came from the complex combination of contaminants, their differing catabolic pathways (VC – anaerobic/ aerobic, 1,2 DCA – anaerobic, co-metabolic aerobic, Chloroform – anaerobic, Chlorobenzene – mainly aerobic, 1,3 DCB – anaerobic), the orders of magnitude reductions required to meet the remediation targets, and the nature of the soils requiring treatment. It was decided that the most applicable solution would be to employ a “treatment train” approach. Lab trials were carried out before the full-scale works commenced to optimise the various amendment addition rates to achieve maximum contaminant mineralisation, transformation, and contaminant mass reduction at all stages of the treatment train approach. Prior to treatment, the excavated stiff clay materials had to be physically processed to expose the contaminants of concern to various amendments. They broke the material up using a bespoke batch mixer that HBR used to ensure material was sufficiently blended with the daramend additive used, ensuring contact with the targeted chemicals of concern.


Best use of a Combination of Remediation Techniques

This was followed by an initial aerobic period, which involved creating large biopile cells that were suitably amended and aerated using a closed SVE system embedded within each of the cells. These were closely monitored to ensure optimisation was achieved and maintained and fugitive emissions were negated. Daramend is a commercially available amendment, which is essentially a mixture of ZVI and plant fibres. The iron is used as a direct chemical reductant on the chlorinated VOCs and to stimulate anaerobic biological dehalogenation reactions via metabolism of the plant carbohydrate. Where recalcitrant compounds were identified in grossly/ DNAPL saturated soils, these were then targeted with ex-situ direct chemical oxidation. Geotechnical modification was then accomplished with a final lime stabilisation stage. The anaerobic bioremediation included: n bench-scale testing for optimal daramend addition n a propitiatory batch processor to break cohesive soil up, helping ensure good contact by the daramend n placement of soil into purpose-built bio-piles. Each bio-pile was sub-categorised into discrete sub cells, ensuring materials could be tracked using the materials management plan n maintenance of the anaerobic environment to promote anaerobic degradation n key performance monitoring through routine soil sampling n and reducing concentrations of compounds of concern The ex-situ soil vapour extraction/ physical stripping involved: n inclusion of SVE pipe beds in bio-piles to allow switching to SVE/volatilisation/ physical stripping n key performance monitoring n reducing concentrations of compounds of concern/cumulative mass recovery in the vapour phase n material re-sampling and screening against the remedial criteria. Materials that passed were scheduled for stabilisation and were reinstated into the excavations n continuing materials that required further treatment along the treatment train for chemical treatment The ex situ chemical oxidation included: n bench-scale testing for optimal addition of oxidant and activator n field trials n key performance monitoring and reducing concentrations of compounds of concern n the geotechnical improvement of soil post remediation – lime addition to achieve optimal moisture content for backfill.

Brownfield Briefing Awards 2017 | 5

Reducing the pollution burden All soil was successfully treated to fall below the remedial criteria so that it no longer posed an unacceptable risk to human health (or the environment) and was suitable for commercial end use. All material was tracked using a robust materials management plan and validated using a UKAS-accredited laboratory. All results were screened against the remedial criteria for each tracked cell of 200m³ material. An area of land within the site has now been made useful and is ready, both in terms of chemical and geotechnical quality, for future plant expansion. Daramend-treated materials showed a decrease in specific contaminants up to 97%, and grossly impacted materials treated by Chemox showed a reduction up to 98% for specific contaminants.

Acceptance and compliance Remediation works were carried out through a Town Planning Application. The client, AECOM, and HBR engaged early (before the submission of the planning application) in the programme with the statutory stakeholders who included the Contaminated Land Officer, Environment Agency, and Natural England. Consultation with the EA continued following the treatment phase of works to obtain permission to pump excavation water into the site’s effluent treatment plant and into the river. Information boards were erected at the pedestrian side of fence lines to keep client personnel informed of progress and information signs were posted along client site boundaries to explain to the general public the work that was being carried out. The remediation works provide the potential for future plant expansion and potential job creation within the local area. All works were completed fully in accordance with stringent health & safety procedures. In doing so, in spite of the

hazardous nature of the works, there were no reportable accidents during the 12-month treatment duration. AECOM and HBR were successfully audited by the Health and Safety Executive while works were still operational and also by the client. To meet the requirements of its Environmental Permit and the clients’ stringent OHS standards, AECOM implemented a rigorous environmental monitoring regime including for noise, dust, odour, and VOCs at various locations surrounding the treatment area, treatment plant, and site boundary. Environmental quality standards were not exceeded during the works and no complaints associated with noise or odour emissions were received by any of the client’s operational staff throughout the works. “It has been a pleasure to work with AECOM, HBR, and the associated subcontractors on this complex project,” said the client’s project manager. “We set out to work as a totally integrated team with mutual trust and cooperation being paramount between all parties. This approach has been instrumental to a successful remediation project being carried out safely, on time and on cost leaving a very satisfied client”. The project was subsequently held in such high regard by the client that it was hailed as its global flagship remediation project, with representatives from their offices worldwide invited to observe the site operations.

Judges’ Quote: “We liked the way AECOM and HBR used a combination of techniques in a systematic way and resisted the temptation of going for the magic bullet approach. It was a well presented, novel application that could be adapted on other site.“


6 | Brownfield Briefing Awards 2017

Best In-situ Treatment

JOINT WINNER

In-Situ Thermal Remediation Enhancement of a Dual Phase Extraction System ORGANISATION

Arcadis This submission demonstrates the positive outcomes that have been achieved through the continuous adaption of remediation technologies, with the goal of achieving the greatest impact balanced against the cost effectiveness and sustainability of the solution. The success of the remediation of this site starts back with the detailed characterisation undertaken some years ago, which itself was awarded the Brownfield Briefing Award for Best Scoping or Operation of a Site Investigation in 2012. Since that time, a remediation system has been operated at the site, comprising soil vapour extraction (SVE) and dual phase extraction (DPE) technologies. Following a review of the remediation performance in 2016, the decision was made to enhance the system via an in-situ thermal remediation (ISTR) approach. Through implementation of traditional remediation techniques, including SVE and DPE, Arcadis successfully removed more than 8,500kg of trichloroethene (TCE) contaminant mass from beneath the site over a period of 36 months. With declining mass recovery rates, the DPE system at the site was enhanced with ISTR, enabling the recovery of a further 1,520kg of contaminant mass within 10 months, which would otherwise not have been recovered.

Site strategy The site occupies an area of approximately 8,200m² and was previously used for the manufacture of electronic control units and sensors. It is planned for redevelopment as a commercial property and bound by sensitive receptors, including a school premises, community hall, and residential properties. Following closure of the site in 2010, Arcadis was appointed to support with the site investigation activities in support of the site’s divestment. The investigation activities focused on developing a detailed conceptual site model through a combination of investigation methods, the outcome of which included a 3D geological model. This helped conceptualise the likely

pathway for DNAPL migration in sand lenses, followed by sorption to the adjacent clay deposits, and supported the design of the remediation strategy for the site. The strategy for the site initially comprised the operation of an SVE and DPE system, designed to both mitigate the off-site migration of contaminated groundwater and soil vapours, but also to target the reduction of the contaminant mass in the identified source areas. The system was originally commissioned in 2013 and operated for a period of 36 months until the middle of 2016. During 2016 it was observed that contaminant recovery rates were beginning to plateau and were forecast to become asymptotic during late 2016/early 2017. Recovery rates had dropped year on year from an average of 589kg/month in 2013, to 87kg/ month in the first half of 2016. Based on this, a decision was made between all stakeholders, and with agreement from the regulators, that rather than go into a lengthy monitoring period to the operation of the DPE system would be enhanced with ISTR. ISTR had originally been considered at the start of the project, but, due to the significant extent of the original source and plume area, it was identified to be grossly cost prohibitive. However, once the source and plume areas had reduced following the success of the DPE and SVE operation, it was clear to see where the use of ISTR would have the greatest impact in supporting closing out remediation activities at the site. The ISTR system was then designed, commissioned and installed by Arcadis in June 2016. The system was then operational between June 2016 and March 2017 for 10 months. The ISTR system involved the following: n connection of additional vapour extraction points in areas where high levels of residual contaminant mass continued to reside to the existing SVE and DPE system retained on-site to control vapour recovery n selection of 25 heating locations across the site, within the four main target zones where concentrations of TCE were measured in excess of 100 mg/l. Electrical conductive

heating elements were installed between 4 and 8m below ground level. n the heating elements were then raised to a temperature of 500°C, providing an increase in ground temperatures in excess of 60°C within 3m laterally of each heating location, and up to 100°C within 0.5m, across the soil profile. n extracted soil vapours were then passed through a heat exchanger prior to treatment via a bank of vapour phase activated carbon vessels. All vapour discharges were treated to a concentration of <1ppm bearing in mind the sensitivities of the neighbouring receptors, with starting vapour concentration in excess of 2,000ppm in some locations at the point of extraction.

Demonstrating best practice The project demonstrated best practice in several important areas. To such area was the optimisation and combination of remediation technologies. Through regular weekly monitoring of the system performance during the project, the remediation process was continually optimised to ensure the system focused on achieving the greatest impact on reducing the contaminant mass beneath the site. This included the adjustment of groundwater pumping rates and pumping locations, the adjustment of vacuum levels at individual extraction locations and, installation of additional groundwater and soil gas extraction points to support additional mass recovery. This process was supported by continuous remote monitoring, enabling any system faults, drop in temperatures, or power outages to be picked up and dealt with immediately. A second area where best practice was put in place was in the application of remediation system enhancement rather than monitoring. The ISTR enhancement of the remediation system on-site at a time when contaminant recovery rates were becoming asymptotic, as opposed to switching the system off and moving into a prolonged period of monitoring, supported the recovery of a significant proportion of additional contaminant mass.


Best In-situ Treatment

Based on a review of the data collected as part of the remediation process, it was clear that residual contaminant mass was residing within the more cohesive zones beneath the site, which had the potential to ‘bleed’ back out into the aquifer in the future. ISTR was identified as the best technology to support further remediation efforts at the site, directing the heat from the conductive heating probes into these cohesive zones. In terms of sustainability in design, it was recognised that the implementation of an ISTR approach at the site would significantly increase the carbon burden associated with the remediation system, with a four to five fold increase in energy consumption rates. As such, the effectiveness of the ISTR system was monitored closely each week, allowing for clear decision making each month over whether to extend the lifetime of the ISTR system or switch it off. The decision was made to switch it off after 10 months when it was clear that recovered soil gas concentrations returned to pre-ISTR levels, but also that the mass of CO2 (kg) per kilogramme of TCE (total) recovered no longer demonstrated that the system was providing a significant benefit to the environment. Regarding cost effectiveness and durability, the ISTR enhancement of the existing remediation techniques implemented at the site has led to the robust treatment of the contamination present beneath the site, building on the success of the investigations and subsequent DPE/SVE remediation approach. This is evidenced by the significant mass of TCE recovered during the relatively short operation of the system (10 months) and improvement in conditions beneath the site.

Brownfield Briefing Awards 2017| 7

The ISTR upgrade to the system supported the removal of an additional 1,520kg of contaminant mass in the 10 months of operation, averaging at 155 kg/month with a peak of nearly 200kg (comparable 2015 levels) before reducing to levels comparable with the DPE/SVE system prior to the switch-on of the ISTR system. Vapour phase recovery rates increased by up to 210% at the peak of the ISTR systems operation. Continuous monitoring of recovery rates and system performance ensured that the cost effectiveness and sustainability of the remediation process was continually optimised. In terms of reducing the pollution burden, the remediation process is considered to have had a huge impact on reducing the pollution burden beneath the site, and a large part of this was grasping the opportunity to proactively install and operate the ISTR system to recover contaminant mass which could otherwise be have been left in place and likely further delayed the redevelopment of the site back into beneficial use. Community and stakeholder acceptance was also a significant part of the project. Liaison with the regulators and local stakeholders including the school, church warden and neighbouring residents was ongoing throughout the remediation process. Regular contact was made with the neighbouring land owners to facilitate ongoing access off-site to permit groundwater and soil gas monitoring on a quarterly basis. Following the cessation of the ISTR activities in March this year, it has been agreed with the regulators that following the ISTR cool down phase planned for completion in July 2017, the remediation

system can then be removed from site allowing plans then to be made to support the site’s redevelopment. Throughout the remediation programme there has been a continuous focus on the Health and Safety of those performing the work, but also on stakeholders surrounding the site which had the potential to be impacted by the changing vapour conditions beneath the site. Some of the key initiatives taken during the project include: n weekly site visits to check treated vapour discharge conditions and boundary site conditions n fortnightly site audits to confirm the system is operating in accordance with the requirements of the site’s Environmental Permit and all critical safety devices are operational n quarterly off-site soil gas monitoring and testing around the sensitive neighbouring receptors including the residential properties and school n full-time remote monitoring of the system operation to allow for immediate identification and rectification of potential faults n installation of a bank of eight lead and lag vapour phase activated carbon vessels, allowing carbon changes to be arranged immediately on breakthrough of the lead vessels, whilst the lag vessels continue to treat the contaminated vapours to <1ppm n and installation of a back-up generator to maintain the operation of the vapour extraction system during the ISTR phase of the project and in the event of a power cut to the site. Judges’ Quote: “The Arcadis entry showed very clearly what has been achieved by both the original SVE/ dual phase system and the effectiveness of enhancing with thermal.”

Total Contaminant Mass Recovery – 2013 to 2017 (kg)


8 | Brownfield Briefing Awards 2017

Best In-situ Treatment

JOINT WINNER

Sustainable Low Temperature In-Situ Thermal Remediation of Pesticides ORGANISATION

ERM ERM was commissioned to investigate and treat legacy contamination beneath a building at a wood treatment testing facility. The site investigation activities, using a combination of traditional and high resolution site characterisation techniques, identified impacts from kerosene and the pesticide dieldrin, to saturated gravels that overlie the regional chalk bedrock. Contaminant mass was present mainly as sorbed phase kerosene and other hydrocarbons, with dieldrin entrained within this product. The dieldrin was shown to present a potential risk to a nearby river and the chalk aquifer groundwater. To mitigate these risks, a source zone remediation strategy was implemented using an innovative steam enhanced mobilisation process to simultaneously recover kerosene and dieldrin.

Remedial Targets Methodology and the UK Sustainable Remediation Forum (SuRF) framework, incorporating sustainability as an integral part of the technology selection process. The results showed thermal remediation could address both the kerosene and pesticide impacts, although relatively high temperatures of circa 350ºC would be required to volatilise dieldrin; this could only be achieved using a series of closely spaced heating wells via in-situ thermal desorption (ISTD) as the heating methodology. This high temperature strategy was assessed using PetraSim™ thermal modelling software to simulate two different well configurations and in both cases confirmed relatively high energy consumption would be required.

Characterisation and risk assessment

Given the magnitude of the CO2 consumption and associated energy demand, ERM investigated use of an alternative lower carbon strategy of changing the heating methodology to steam enhanced extraction (SEE); this was not initially considered as steam could only reach temperatures of circa 100ºC, considerably below the target treatment temperature (TTT) to volatilise the dieldrin. However it was considered that if the kerosene could be recovered via mobilisation and simultaneously remove the lower mass (but higher risk) of dieldrin, then this approach could be plausible and would significantly lower the carbon footprint; therefore this was bench tested to confirm effectiveness of reducing total concentrations of kerosene (TPH) and dieldrin via mobilisation of the closely associated kerosene and dieldrin. The results of the bench testing demonstrated that dieldrin was likely solubilised in the TPH and could be removed at temperatures of between 70 to 100ºC, where dissolved phase concentrations of both dieldrin and kerosene (TPH) are shown to increase at temperatures of 70ºC as a result of mobilisation, but then decline at 100ºC – a result that means mobilisation must be

Site characterisation was undertaken through an intensive programme of soil sampling and groundwater investigation using a Modified Waterloo Profiler, which is a direct push, discrete interval sampling technique. These methodologies confirmed and accurately delineated impact within the underlying high permeability gravel deposits to a depth of up to 4m below ground level (bgl). The main contaminant of concern within soil and groundwater was dieldrin, given its ability to migrate laterally and downwards into the underlying chalk aquifer. The contaminants were predominantly located beneath an area historically used for chemical storage. A controlled waters quantitative risk assessment indicated that the greatest potential risk from the impact was longer term vertical migration of dieldrin towards the chalk aquifer. The remedial strategy therefore focused on maximising mass removal of this compound as part of a risk reduction strategy. A remedial options appraisal was undertaken using a holistic sustainability approach, where environmental, social, and economic indicators were evaluated to determine the most sustainable option in accordance with CLR11, the EA’s

Lower carbon strategy

removing the contaminants given that this temperature is well below the boiling point of dieldrin.

Remediation design and operation The modelling and bench test work confirmed a change in the traditional and originally envisaged methodology of thermal recovery (volatilisation) to one of mobilisation, with the associated TTT reduced significantly from 350°C to 70ºC. This change now meant steam rather than ISTD could be used to heat the subsurface using less wells and energy. The thermal model using steam was then further developed to optimise steam injection well locations and predict heat-up duration for the revised TTT. This provided further benefits to the client and wider project team in that by estimating the energy use the most economic fuel source and power tariff could be selected; the process kit rental time could also be predicted/optimised improving cost estimates and certainty of programme schedule, a critical requirement for the client. The results of the modelling showed that the optimum well configuration comprised 19 DPVE wells and 19 steam injection wells within the approximately 1,500m² treatment area. Ninety temperature monitoring points were also installed within the treatment zone, at three different depths, to allow the heating process to be monitored and optimised. The wells were linked to process equipment, which included soil vapour extraction blowers, a heat exchanger, inlet tanks and carbon vessels for treatment of vapour and liquid phase. Following installation in January and February 2017, the pumping and SVE system was initially operated during March 2017 at ambient temperatures to confirm capture zones and extract readily recoverable mass. Steam was initiated in early April and the target temperature of 70ºC was rapidly achieved within four to five weeks and then maintained while significant quantities of LNAPL (containing kerosene and dieldrin) were recovered via


Best In-situ Treatment

Brownfield Briefing Awards 2017| 9

mobilisation of the kerosene. ERM developed an innovative data management system for this project, where data from the thermocouples was automatically uploaded to EquIS software on a daily basis and then outputted into Tableau visualisation software. This enabled ERM to confirm model predictions, optimise the steam injection, and hence minimise energy consumption; it also provided the US-based client with an understanding of key performance metrics on a near real-time basis. A webcam was installed to view the works undertaken remotely.

Validation and close out The target source-zone was brought up to temperature through controlled injection of steam. Mobilisation of LNAPL was observed as temperatures approached 70ºC. The majority of the mass was removed as kerosene NAPL via mobilisation (reduction in viscosity). Elevated concentrations of dieldrin were also detected within recovered NAPL and liquids, confirming success of the lower temperature mobilisation concept and the bench test results. The remedial strategy agreed with the client, regulators, and other stakeholders was a risk reduction approach of mass recovery that was feasible with the identified technique, with an achievement end point of asymptotic contaminant recovery. This condition is approaching and an estimated contaminant mass of 3,000kg has been achieved to date. In addition to a mass recovery of the same order of magnitude as the original mass balance, interim remediation groundwater sampling has not detected any dieldrin concentrations above the laboratory method detection limit in contrast to the pre-remediation baseline sampling. It is anticipated the system will run until the end of June 2017 to confirm recovery has been maximised.

Best practice Best practice was demonstrated in several elements of the project. A sustainability

Estimated Carbon Consumption for different heating methodologies/ configurations (CO2 kg equivalent use).

based remedial options assessment was completed in accordance with UK guidance. It concluded that in-situ thermal treatment would be most applicable and cost effective given the technical challenges to remove pesticides from the subsurface and that rapid remediation was required. The project illustrates how energy, cost, and time savings can be made via a combination of thermal modelling and bench testing to demonstrate a significant change in TTT (from 350ºC to 70ºC) could be made from the originally planned concept, allowing a change in heating technique. The use of the thermal model also enabled the system design to be optimised (well spacing and heat input), the energy source to be confirmed, and the operation to proceed in the most efficient way (real time data collection to confirm model results). The project confirms the applicability of thermal remediation to remove entrained pesticides via mobilisation of oils at temperatures well below the boiling point of these compounds. The data management procedures applied at this site were well above industry standard and used an integrated database and online platform to visualise key performance data (heat up progress and mass recovery), providing benefits to ERM and the client. This also involved collaboration with Information Solution experts outside of the contaminated land industry. In terms of cost effectiveness and durability, the approach adopted used innovative low temperature removal mechanisms to complete the operational phase more cost effectively than was originally envisaged. A significant reduction of the pollution burden was also achieved - the remedial technique selected rapidly maximising mass removal at a lower temperature than conventional application of thermal technology would have achieved. This reduced energy consumption and time, reducing the overall project costs. Regarding community and stakeholder acceptance, all project stakeholders were consulted throughout the project. ERM kept

Laboratory Bench Test Results.

the EA informed throughout the project, including facilitating a site visit/training session during operation. The robust remedial approach undertaken enabled endpoints to be agreed quickly with the regulators. ERM also held weekly meetings with the client to discuss a wide range of issues, including H&S and integration of remedial activities with site activities. The works were completed safely, on schedule, on budget and to the satisfaction of all stakeholders.

Health, safety, and sustainability ERM and the remedial equipment supplier instigated a proactive, sustainable approach to health and safety which frequently considered the risks in the context of an operational site. The work also fell under the Construction (Design and Management) Regulations (2015). In addition to typical risks considered for any in-situ remediation project, the following was also undertaken: n process safety was carefully considered at design stage and several reviews were undertaken, the outcome of which added several process safety features to the remedial equipment n thermal specific H&S hazards were included within the project risk assessments n a strong safety culture was embedded within the project team to ensure that any observed hazards were identified and addressed. The work was undertaken with no lost time accidents over a period of about 3,500 hours mentoring of junior staff was undertaken face-to-face throughout the works five project audits were also undertaken in accordance with ERM’s global Active Safety Management approach, with lessons learnt fed back into the project and wider business Sustainability was also a key consideration throughout the project’s lifecycle. The use of innovative investigation techniques demonstrated a lower carbon footprint than if multiple phases of traditional site investigation had been undertaken. A combination of sustainability led remedial options appraisal, modelling, and bench testing were key to deriving the lowest carbon footprint for the most technically applicable solution. The remedial approach focused on carbon footprint reduction in other practical ways such as the use of: a gas powered steam boiler; the mobilisation methodology to enable a significantly lower TTT, reducing energy consumption and carbon footprint; and thermocouples and real-time data review systems to optimise heat injection. Judges’ Quote: “ERM’s is a strong entry that illustrates the careful design and application of thermal technique together with very clear evidence of an effective system.”


10 | Brownfield Briefing Awards 2017

Best Conceptual Design

WINNER

Chapelcross Magnox; Chlorinated Solvent Plume Remediation Design ORGANISATIONS

Magnox and Arcadis During operation of the Chapelcross nuclear power generation site, waste solvents were lost to ground. The solvents were predominantly chlorinated hydrocarbons (CHC) into which non-chlorinated hydrocarbons (HCHCs) were dissolved during use. Arcadis site investigations identified several contaminant source components. The SI identified an area of predominantly NCHC-contaminated soil in glacial till above the permanent groundwater table. Due to site constraints, the contaminated material could not be excavated. A non-Aqueous phase (DNAPL) component of predominantly CHC was also located in the fractures of the Triassic sandstone aquifer. An aqueous (dissolved) phase plume of CHC and NCHC was identified that exceeded 850m in length and extended to the site boundary within the groundwater of the sandstone. This plume was further divided into that which was present dissolved within groundwater in the fractures and that which had diffused from the fractures into the pore water of the sandstone matrix.

Case histories from the US Environmental Protection Agency demonstrates that the remediation of chlorinated solvents to regulatory standards within fractured aquifers is notoriously difficult. The remediation concept is designed to achieve objectives agreed with all stakeholders using an innovative combination of technologies including: soil

source treatment to prevent unacceptable inputs to groundwater; groundwater source treatment to destroy contaminant mass; and near-source-plume treatment to achieve agreed assessment limits within a significantly reduced timescale. By design, the remediation can be implemented without disruption to site operations, has a low environmental footprint, and the agreement of the regulators.

Remediation strategy development Arcadis conducted a high quality innovative multi-phase, multi-technique SI to characterise the contaminants, geology, and hydrogeology beneath the site, leading to the production of a detailed conceptual model. With the benefit of this detailed knowledge, our approach to developing a remediation strategy was to: use an early stage in-situ pilot remedial trial; engage early with the regulators to agree objectives and remediation targets; undertake a remedial options appraisal of the technologies capable of achieving remedial objectives and targets given the identified site-specific constraints; produce an outline remediation strategy, for agreement with the client and regulators; and produce the detailed design of the optimised remediation strategy. The remedial objectives agreed with all stakeholders including the regulators were to prevent further unacceptable entry of hazardous substances from the soil source to groundwater and to remove sufficient DNAPL mass and reduce dissolved phase contaminant concentrations in the

groundwater source zone to the extent that contaminant concentrations cease to exceed assessment limits at the site boundary. The main technical constraint to successful remediation was that the approach had to address DNAPL located in the hard rock fractures at considerable depth and address the slow back diffusion from the sandstone matrix. The remediation strategy that best addressed the above technical challenges and hence could best achieve the remedial objectives without entailing excessive cost was identified as follows: Action A – soil source treatment: engineered cover (with surface water drainage) to reduce infiltration through the soil source in the glacial till, where soft cover currently prevails. Action B – soil source treatment: application of a proprietary blend of electron donors injected into the base of the glacial till to promote enhanced reductive dechlorination (ERD) of CHC leached from the soil source. Action C – groundwater source treatment: in-situ ERD of CHC through the introduction of electron donors into the groundwater source to address the residual DNAPL and associated high dissolved phase contamination within the fractured sandstone. The sustained release function also addresses the higher severity (early years) back-diffusion inputs from the sandstone matrix. Action D – Plume treatment: An on-site downgradient treatment barrier/zone (DTZ) using a technology based on a combination of an organic carbon source to promote ERD of the source zone daughter products, Zero valent iron (ZVI) for direct in-situ chemical reduction of chlorinated volatile organic compounds (CVOC) and an activated carbon component for adsorption of NCHC. The plume treatment ensures compliance with assessment limits at the site boundary within a reduced timescale compared to source treatment alone.  


Best Conceptual Design Demonstration of best practice The project demonstrates best practice in the several areas. The PRT demonstrated that the use of the electron donor substrate in the sandstone aquifer significantly promoted ERD, increasing the degradation rate of the CHC source (primarily PCE) and the production of breakdown products through to ethene. The PRT also provided an indication of reagent injection characteristics and actual contaminant migration rates through observation of the arrival of the breakdown products in a down-gradient borehole external to the PRT area. Secondly, fate and transport modelling was conducted to delineate the size of the treatment zones and to assess the benefit and optimal location of the DTZ. Data obtained from the PRT, especially contaminant migration and degradation rates, were used to produce a robust numerical model. A high quality innovative multitechnique SI was also employed in multiple phases to characterise the site and refine our conceptual understanding. These techniques specifically informed our optimised remediation design. Thin sections were obtained from cores and petrographic techniques were used to assess the pore throat size and the effective porosity of the sandstone. From this, we demonstrated that DNAPL could not enter the matrix. We calculated the mass of dissolved phase contamination in the matrix and in turn the likely restricted longevity of back diffusion. A soil vapour survey helped to delineate the extent of the residual soil source in the unsaturated glacial till. This informed the size of the source zone treatment areas. Geophysics (especially natural gamma) and packer testing were used in combination to identify varying permeability horizons in the sandstone to inform our substrate injection strategy.

Cost effectiveness, durability, and reducing the pollution burden The Arcadis remedial design offered excellent cost benefits, being approximately £500,000 cheaper than other competitor tendered designs. No preliminary works were required by the client to enable remediation (e.g. movement of operations and demolition of buildings). Arcadis also provided cost certainty into the design as most of the remediation costs (approximately 70%) are associated with the emplacement of the reagents. This cost has been controlled through assessment of mass flux in the aquifer to enable accurate reagent dosing. In addition, the use of long-life reagents, as well as pilot testing before implementation, means the risk of needing additional reagent injections is reduced.

Brownfield Briefing Awards 2017| 11

The client’s decision to optimise the design by installing the DTZ during the main treatment phase rather than adopting a “wait-and-see-if-required” approach resulted in a cost-effective design that goes beyond what is required to achieve regulatory assessment limits, creating greater certainty in the outcome. The remediation aims to remove or destroy contaminant mass, as well as achieving assessment limits. The remediation will have a significant impact on reducing the pollution burden for the next generation. Based on the results of the PRT, we believe the remedial work will destroy more than 90% of the contaminant mass present as DNAPL and dissolve inside the sandstone fractures within 24 months. Destruction of contaminants in the soil and dissolved within the matrix will take place at a slower rate, resulting in an overall contaminant mass reduction of 80-90% within 24 months. Fate and transport modelling has demonstrated that there will be no (regulatory) unacceptable impact at the site boundary. Validation will be conducted via monitoring.

Acceptance, safety, and sustainability Early stakeholder consultation was fundamental to the success of the project. The remediation of historically contaminated land on a permitted site in Scotland falls under two potentially conflicting regulatory regimes. Early regulator engagement resulted in a strategy that navigated the two regimes and was appreciated by the client and regulators alike. The approach adopted by Arcadis was subsequently shared within the industry. The NDA disseminated the Arcadis technical note as effective learning for the Dounreay site as it “pragmatically navigates two regulatory regimes, with SEPA ‘advocating’ the approach we used”. Arcadis supported the client during stakeholder engagement meetings with the adjacent landowners (under whose land the plume had extended) together, obtaining their acceptance of the remedial strategy. The protection of Health and Safety was also inherently designed into the remedial works. Reagent-related risks were eliminated in the source zone treatments as the electron donor substrate specified is a low-hazard, food-grade carbon source. Risks associated with drilling and injection works were reduced at detailed design by using fewer injection boreholes in combination with a less viscous electron donor substrate. A detailed injection equipment design prevented incorrect pressure rated hoses and fittings being connected. This prevented the over-pressurisation of lines in the event of a blockage and required pressure gauges to be fitted to monitor pressures during injection

works. The injection locations were refined with the client to avoid heavilytrafficked and highly-used areas. Finally, traffic management and working area segregation plans were included in the final detailed design . In terms of sustainability, the remedial design has a low environmental footprint compared to potential alternative remedial options as it is less energy intensive, generates little waste or emissions. Sustainability was further enhanced during the detailed design process. The number of injection points was reduced by using a less viscous electron donor substrate. The mass of reagents used was minimised by mass flux targeting of horizons, optimising the size of the source treatment zone and selecting the optimal location for the DTZ . The number of phases of work required at the site was minimised by selecting reagents that have longevity in aquifer systems to reduce the number of repeat injection and the client’s decision to install the DTZ during the main works phase.

Best assessment of remediation options Arcadis completed a thorough appraisal of the capability of a wide range of remediation technologies to achieve the two specific remedial objectives (stated previously) that had been agreed with the stakeholders. A key technical constraint considered during the appraisal was that the majority of contaminant mass resides at significant depth in the sandstone fractures as DNAPL. For remediation to be successful, the approach had to address this residual DNAPL as well as slow back diffusion from the sandstone matrix. The assessment was completed following the principles set out in CRL-11. A screening review of potential remedial techniques was conducted by examining their ability to achieve the required remedial outcomes considering the identified technical constraints. First, we considered generic applicability and identified techniques that were potentially viable. Then a more detailed assessment of these short-listed techniques was conducted considering site-specific constraints, resulting in the preferred combination of techniques that was taken forward to detailed design.

Judges’ Quote: “This project provided a clearly laid out description of a process that has removed significant contamination from soil and groundwater. The site investigation was excellent, with unusually early pilot studies helping with EA acceptance for monitoring and remediation.”


12 | Brownfield Briefing Awards 2017

Best Scoping or Operation of a Site Investigation

WINNER

Chapelcross site - assessment of groundwater contamination arising from past use of solvents ORGANISATIONS

Magnox and Arcadis During Chapelcross operation, the Armature Treatment Bay (ATB) had used a blend of chlorinated hydrocarbon solvents (CHCs) to clean motor and generator armatures. Some entered the ground, impacting glacial tills, and forming a dissolved plume in the sandstone aquifer. Action taken in 2007 to excavate the highlyimpacted till only partly influenced the plume. Arcadis designed and delivered an integrated and phased investigation to better define the 3D plume and hydrogeological regimes. This was a highly innovative and bespoke approach to develop a detailed conceptual site model (CSM), enabling the following questions to be answered: n Where was the remaining source? n Within which compartments - soils, fractures, or matrix-pores, did it reside? n Was the plume expanding, shrinking, or in a steady state? n Was natural attenuation occurring or stalling? n Would back-diffusion from the sandstone matrix be a key project risk? Assessment of the geochemistry and CHC composition throughout the plume revealed evidence of reductive stall, with prevalence of cisDCE in the mid-plume. However, parent CHC compounds were again present in the distal plume. Something unusual was occurring. An early Remedial Trial was included to inform site characterisation. This was was a great success, saving two years’ programme and providing key data and increased confidence for the client and regulators. Best practice techniques were applied. These included: creation of a time-series database, preliminary CSM, and soil vapour survey to target exploratory positions; continuous percussive sampling techniques in glacial till, rig-side PID screening, and real-time observations; using natural gamma and Visual Televiewer to aid correlation of mudstone beds (potential barriers to downward DNAPL migration) and preferential fissure flow paths; separate examination of plume characteristics within the source, near-source, mid- and

distal plume; petrographic thin sections, informing primary porosity and throat sizes and DNAPL pressure of entry; prediction of residual DNAPL 1% rule of thumb, modified by co-mixture mole fractions (Raoult’s law); multi-level groundwater monitoring, enabling better understanding of two distinct hydrogeological regimes; and the early remedial trial of a fermentable substrate to examine the potential of Enhanced Natural Attenuation AND act as an active tracer. Delineation of CHC movements in fractured media is challenging and several lines of evidence, including lithological, geophysical, and geochemical data, were combined to identify the most credible source and migration mechanisms. The early remedial trial was highly successful, demonstrating that natural processes could be enhanced. The step changes recorded in downgradient observation wells enabled calibration of the Fate and Transport model, providing increased confidence that plume dynamics were now better understood. The staged and innovative approach has provided detailed, less confused, or contradictory information, now underpinning a well conceptualised multicomponent remediation.

The site itself Chapelcross Nuclear Power Station is located approximately 2.5km north east of Annan in Dumfriesshire, Scotland. It is undergoing decommissioning and entered into its Care and Maintenance preparations phase in 2013. Solvents (Ardrox and Genklene) used at the Electrical Maintenance Workshop and Armature Treatment Bays entered the ground and surface water drains in the vicinity of these buildings in the 1960s. Prior to Arcadis’s involvement, pump and treat was trialled. Vacuum extraction and permeable reactive barriers had also been ruled out. The soil source was overexcavated and a period of monitored natural attenuation commenced in 2007. However, by 2012, monitoring revealed that risk to groundwater had not improved. The regulators, Dumfries and Galloway Council

and SEPA, had been kept fully informed. Adopting a voluntary and proactive approach, Magnox instructed Arcadis (formerly Hyder) to undertake a critical review of borehole and chemical data. This review identified the need for higher quality discrete sampling and collection of data on aquifer spatial geochemistry. Phase 1 SI commenced October 2012, with Phase 2 complete by October 2013. Characterisation monitoring continued into 2016. The general strata sequence present is: made ground; glacial till – sandy clay and silt; St Bees Sandstone – dominant fine grained sandstone with subordinate mudstone; and St Bees Shale.

Investigation strategy and outcomes Assessment of characterisation monitoring, borehole, and geophysical data culminated in a detailed CSM. The strategy also included a rock mass structure and depth discrete assessment of hydraulic permeability and phreatic conditions. This was to help establish whether inter-beds of mudstone (dipping perpendicular to the hydraulic gradient) were significant influences on DNAPL penetration and migration pathways. The scope of the ground investigation comprised: n a soil vapour survey to better locate exploratory holes and confirm limit of soil source beyond 2007 excavation limit n testing of preferential pathways such as historic services and drainage n dynamic and rotary cored boreholes, cased down with environmental seals n rig-side PID scanning and sub-sampling n packer infiltration tests to assess


Best Scoping or Operation of a Site Investigation

variation of formation permeability. n downhole geophysics to locate mudstones, examine fracture state, and preferential flow paths, extending to St Bees Shales, the conceptual limit to CHC flow regimes n the installation of standpipes (up to four per borehole pair) equipped with dedicated pneumatic bladder pumps with groundwater sampled using micro-purge techniques n in-situ measurement of well-head stabilisation of DO, pH, ORP, and EC parameters to +/-10% n the creation of a stable database of historic and newly acquired data in Microsoft SQL server and ArcGIS n the early regulatory discussion and the promotion of an early remedial trial to aid characterisation n an assessment of time series compositional relationships and trends Geochemical in-situ data indicated that groundwater in the source and near-source plume was low in oxygen and was mildly reducing. However, it was also low in dissolved organic carbon, a limiting factor on the rate of degradation. The plume was steady state, characterised by PCE in the source zone, and dominant cisDCE in the mid-plume. Compositions for source, mid- and distal plume displayed little change from 2002 to 2014. Unexpectedly, groundwater reaching the distal plume seemed to be by-passing the mid-plume.

Demonstration of best practice Accurate and relevant Information was retrieved for effective risk assessment. Firstly, a CSM-based SI design established relevant pollutant linkages, data for risk assessment, and informed remedial action. It included: drilling targeted by SVS and a time-series assessment of data and geological sequence established by reference to deep drilling for CPX B station; and geological structure, lithology, permeability, rock-mass, hydraulic heads, mudstone influence, residual DNAPL, and in-plume compositions. This relevant physical and geochemistry data informed a developed CSM and Consim transport and fate model. Secondly, an early remedial trial was conducted, which included: the Injection of 2m³ of a slow release electron donor; monitoring of geochemical changes and resultant increase in degradation; the arrival of degradation products at downgradient boreholes was back-analysed, helping to refine and calibrate the fate and transport model. Within 14 months, PCE was fully degraded within the source zone trial and 25% of the cisDCE had degraded to vinyl chloride (VC). Increasing concentrations of ethene gas demonstrated complete

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degradation and no VC stall. Thirdly, petrographic sections were assessed to see if DNAPL had entered the rock matrix. If this was the case, back diffusion would have been a significant remedial hurdle. The pore throat sizes entry pressure was also analysed. The typical grain size was 80µm, of quartz, and feldspar with subordinate mica and mud-clasts. Effective porosity was less than 5%. Critically, pore-throat size was <20µm and for a non-wetting CHC the entry pressure equated to >4m head of DNAPL. Given the gradual release of solvents over decades of ATB operation, risk of entry into pores was ruled out. Remedial options could thus focus on residual DNAPL within discontinuities; matrix back-diffusion would arise from dissolved phase only. Fourthly, the hydrogeological regime analysis consisted of: multi-depth discrete response zones; packer permeability testing high and low rock quality designation (RQD); and geophysical logging to correlate lithology, discontinuities, and ascertain transition to less mobile groundwater in St Bees Shales. A reducing geochemistry was recorded where TPH was also present. Permeability was negligible in solid strata, contrasting with high fissure flows. Semi-perched conditions within upper sandstones were supported by the laminated mudstones. Monitoring of phreatic heads revealed a downward hydraulic gradient under the ATB source area and an upward gradient down plume, enabling CHC compositions similar to parent CHC to be present in the distal plume.

Presentation and communication Regular client and regulatory contact was maintained to agree the approach and review risks and uncertainties. Reporting was subject to Magnox Intelligent Customer sign-off. Work within a Nuclear Licensed Site requires the highest level of pre-planning and safe working. The site team worked with a Magnox radiological protection advisor to minimise hold periods and dispatch under an excepted package process. Best practice was also observed in terms of community and stakeholder acceptance. The plume had extended beneath farmland adjacent to the south west boundary. Regular updates were provided to the landowner and access agreed to minimise impact to livestock relocation. Progress updates were published on Magnox’s website. Private water abstractions were checked, adopting a precautionary basis, to provide confidence. Presentations were made to regulators to communicate CSM and implications for possible remediation solutions. These presentations set out the developed CSM and examined the statutory guidance,

such as GP3 and SEPA WAT-PS-10. Critically, resource protection, rather than onerous minimum reporting values, will be considered as applicable to historic releases where entry to groundwater has occurred.

Cost effectiveness and safety Geophysical techniques reduced coring, with the technique resolving progressively tighter and healed fractures that indicated negligible groundwater flow below 60m. Corresponding EC and temperature rise showed responses characteristic of geologic water. The use of dedicated pneumatic pumps is best practice for VOCs, allowed discrete depth sampling over two years of monitoring, with no risk of crosscontamination. This enabled the collection of high quality, believable, time-series data. This project has underpinned exemplary targeted sustainable remediation. The project also included: the use of costeffective percussive, coring and open-hole methods integrated with geophysical logging; dedicated pneumatic bladder samplers with drop tubes to sample from up to 90m bgl; and adopting a mix of air, or air mist, as the drilling flush to significantly reduce the waste drilling water generated, reducing costs and environmental risk. Arcadis was Principal Designer and Principal Contractor for the project. The main hazards - active decommissioning, nuclear power plant/HGV traffic, underground services, and Chlorinated Solvents - were communicated via a designer’s hazard record/risk assessment. Hyder used “STAR” best practice guidelines to ensure safe work practices for the health and safety of all Hyder operatives, subcontractors, power station employees, and the general public - a key part of the site specific Health and Safety Plan. British Drilling Association category red was applied and mitigation included a decontamination unit, fully sheeted work areas, and sealed drums for the temporary storage of waste drilling water. All samples were assessed and logged on-site prior to testing via an integrated chain of custody system. No reportable or lost time incidents occurred during the works of approximately 2,000 worker hours. Drilling subcontractors were approved members of the BDA and were heavily involved in the full risk assessment for the site works, providing detailed mitigation plans and method statements of all their activities. Judges’ Quote: “The winning entry was clear, focused, and detailed. It centred on a lines of evidence approach rather than relying on one piece of information, which added crucial weight to their arguments. This effort showed why they’re market leaders.”


14 | Brownfield Briefing Awards 2017

Best Project Closure/Verification

WINNER

Coed Darcy ORGANISATIONS

St. Modwen, Atkins, and Prosurv Consult Coed Darcy is an ambitious brownfield regeneration project of regional importance involving the development of a new “urban village” on the site of the former BP Llandarcy Oil Refinery in Neath, South Wales. The need for oil refining capabilities in Britain was recognised during the First World War and this led to construction of the UK’s first crude oil refinery in Llandarcy, with operations commencing in 1922. At its peak, Llandarcy Oil Refinery employed more than 2,500 workers from local communities, processing more than three million tonnes of crude oil annually to produce motor spirit, kerosene, gas oil, lubricating oil, bitumen, and wax. Operations at the refinery ceased in 1997 and process and storage infrastructure was largely decommissioned and demolished following the closure. The resulting brownfield site comprised more than 1,000ha of derelict land, much of it contaminated with petroleum hydrocarbons, the legacy of the previous 75 years of refinery operations. This represented one of the largest single brownfield sites in Europe, bounded on two sides by Crymlyn Bog, a Site of Special Scientific Interest (SSSI), Special Area of Conservation (SAC), and a RAMSAR site. From the late 1990s, BP began to explore potential options for the site with a desire to create a positive legacy for future generations and create Coed Darcy. St. Modwen was chosen as developer and the site transferred ownership from BP in 2008. Following an extended period of negotiation with the site’s stakeholders, planning permission was granted and a Section 106 Agreement signed for a predominantly residential development comprising 4,000 residential units, schools, commercial premises, and public open space. Atkins was appointed by St. Modwen as lead engineer to oversee the remediation, infrastructure delivery, and ecological design of the site. Nine years into a programme of phased remediation and development that is anticipated to last more than 20 years, the site has undergone a transformation and hundreds of new homes are occupied. This level of progress is testament to the project’s robust closure and verification process. While this has led to rigorous solutions to environmental risk as one the world’s first

oil refineries to be redeveloped for residential purposes, it has also greatly improved the perception of the site as a safe place for a community to grow and develop.

Design and best practice It was recognised from the outset that the scale of the proposed development and the unprecedented regeneration of a former oil refinery for predominantly residential use would require best practice in all areas. To ensure that the design vision could be realised, a partnership of organisations comprising St. Modwen, Neath Port Talbot County Borough Council, and the Prince’s Foundation for Building Community established Coed Darcy Limited as a management company to independently monitor the redevelopment. This organisation acted independently of the development process and ensured the remediation standards were upheld on a site that would otherwise have continued blight on the area. As part of the acquisition, St. Modwen set out its clear aspirations as a “statement of intent” and demonstrated the rigorous approach to verification that it would take throughout the project from initial ground investigation, through to completion of construction to achieve the highest standards and confirm the efficacy of the works. Several elements of St. Modwen’s commitment aided in demonstrating the application of best practice within project verification. The implementation of three strategies for the remediation and management of contamination sought to distinguish between the more urgent voluntary works required in targeted locations to mitigate the risk of off-site migration of gross contamination e.g. to the adjacent SSSI. Those works required to ensure safe future site development and the final stage of remediation to be undertaken during construction work including preventative measures such as clean cover and gas membranes. St. Modwen’s commitment set out the minimum standards that would be achieved by the RRW works to ensure protection of site end users. These standards took two forms - Risk Based Screening Levels (RBSL) for key anticipated contaminants in soil and groundwater, accompanied by

aesthetic criteria that were set to manage perceived visual or olfactory “nuisance” contamination of material, which can be otherwise demonstrated to already meet the RBSL. In recognition of the periodic release of new toxicological data, Atkins derived its own set of site-specific Remedial Target Criteria (RTC) that superseded the adopted RBSL if they were found to be more stringent. As a means of ensuring the highest standards were maintained throughout ground investigation and remediation, Coed Darcy Ltd appointed Aecom as independent Monitor of the works. Aecom reported directly to Coed Darcy Ltd and provided independent certification that parts of the site could be released for development. This system ensured a ‘double lock’ of approvals were required providing the environmental authorities with a system that complemented the planning approval process. St. Modwen’s commitment also demonstrated the approach to project verification as an iterative process applied throughout the entire project rather than at the anticipated completion of remedial works only. The established verification process for Coed Darcy requires: n ground investigation, sampling and laboratory analysis across the site to a specified frequency n removal of oil-saturated soils and free product, validated by strict application of the aesthetic criteria n excavation and removal of soils identified to exceed the permitted RBSL/RTC or aesthetic criteria for ex-situ treatment at the on-site bioremediation facility n sampling and laboratory testing of


Best Project Closure/Verification

remediation excavations to a specified frequency depending on the proposed end use to demonstrate removal of identified contamination n sampling and laboratory testing of site-won stockpiled material to specified frequency depending on the proposed end use to demonstrate suitability for intended use n sampling, testing and assessment of aesthetic criteria of material which has undergone treatment at the on-site bioremediation facility prior to removal and re-use within the project n sourcing, sampling and testing of clean cover materials and independent inspection of this installed cover layer to ensure sufficient thickness at each development plot depending on the proposed end use n installation of an independently-verified vapour membrane in all buildings.

Assessment of residual risk and risk management It is recognised that with a site of this nature, there will always be an element of residual risk and the established three-tiered approach to verification and risk management through RAP works, RRW works, and preventative measures during construction sought to ensure an acceptable level of residual risk based on robust verification of each of these three important components. A degree of pragmatism was employed during the remediation validation process, for example by the use of statistical analysis to assess the risk posed by localised exceedances of the RBSL/RTC or to retain in situ material present at a depth that was characterised by a slight exceedance of the required aesthetic criteria but which met with the adopted RBSL/RTC. Full justification in each of these cases was provided in the validation report for the relevant area of the site and assessed by Aecom. An ongoing aspect of risk management requires monthly water sampling at consented surface water discharge locations, carried out in conjunction with Natural Resources Wales. This monitoring focuses on residual impacts to Crymlyn Bog from contamination at the site and seeks to enable early intervention should this be identified.

Remedial objectives, acceptance, and monitoring The remedial objectives for Coed Darcy are two-fold. The RAP and RRW works and subsequent preventative measures were designed to meet environmental requirements, and certification and completion of RAP works and full redevelopment of the first residential plots at the site demonstrate how the objectives were successfully met and verified. The second aspect of the remedial objectives is considered to relate to St.

Brownfield Briefing Awards 2017 | 15

Modwen’s desire to implement a positive legacy for the former oil refinery and to enhance the area to the benefit of the local community. The scale of the project means the Coed Darcy is already providing a focus for regeneration in the area and providing the core housing provision in the local plan. There are obvious complexities associated with residential development on a former oil refinery, not least the issue of public perception. From conception it was recognised that gaining buy-in from the public and in particular the local community would be key to the success of the project and a stringent verification process would be instrumental in attaining this. A requirement of the Section 106 was completion of the initial site-wide remediation within a seven-year timeframe to improve the overall image of the site and to show that the proposed works would result in demonstrable improvements to the environment and local community. An accelerated area of development, known as the ‘Demonstration Village’, was procured by St. Modwen to show remediation could be completed and verified and to showcase the end result of the project. The inclusion of an aesthetic criteria approach to verification sought to address the issue of public perception in relation to visual and olfactory contamination. It was recognised that the sole application of the adopted RBSL (and later RTC) may not have dealt with material exhibiting evidence of contamination that could be perceived as unsafe by the general public. In addition to the Monitor and Planning process, certification is also provided on the housebuilder works prior to each house sale which serves to demonstrate the suitability of the land for a residential end use. Agreement of the Section 106 was significant in demonstrating acceptance of the proposed verification of works at each stage of the project by the regulatory authorities. The strict standards set out provide confidence in the intended outcomes of the project.

Also, the workforce comprises more than 90% local labour and more than 3,000 jobs are anticipated to be created within the mixed-use development. This is considered to be key in gaining acceptance of the Coed Darcy vision by the local community. Under the direction of Atkins, more than 6,500 independently selected exploratory holes were undertaken across the site between 2014 and 2015 at specified frequencies according to the proposed end use. The large resulting dataset provided confidence to the project team and regulatory bodies in the overall chemical and aesthetic quality of soils at the site. Gathering and assessing this data represented the first stage of verification and a team from Atkins worked full time on the coordination and management of these works. The same team from Atkins was responsible for subsequently scoping, implementing, and validating the RRW works and this continuity was invaluable in ensuring the consistency of approach across such an extensive site. Selected members of the team also had responsibility for working closely with the housebuilder at the site to provide the final stage of verification of validated, imported clean cover, and membrane installation. In addition to Atkins’ responsibilities, the presence of Aecom as Coed Darcy Monitor provided an additional level of assurance. A GIS interactive map has been prepared that holds remediation records and Monitor reports for all areas of the site. This map has formed part of a robust information archive, enabling a dynamic approach to stakeholder engagement particularly with regulators and the local authority. Judges’ Quote: “This entry demonstrated an impressive approach to a project of such size, with the provision of a GIS-based database of environmental information from the verification process catching the eye in particular. Overall, this was a highly organised scheme that clearly demonstrated good practice.”


16 | Brownfield Briefing Awards 2017

Best Public Participation (including use of visualisation)

WINNER

“Making Places” – National School Photography Competition ORGANISATION

St. Modwen St. Modwen is the UK’s leading regeneration specialist of brownfield land, committed to improving the built environment through our projects - all of which seek to transform derelict areas and disused sites - transforming them into cleaner, greener, and brighter environments. To St. Modwen the regeneration is about making positive and genuine changes to communities, the environment, and economy. To mark 30 years as a listed company, in 2016, St. Modwen launched a photography competition as an opportunity to engage with the local communities in which its brownfield regeneration projects are located. Entitled “Making Places”, the competition was principally designed to make a new and wider target audience aware of the benefits of brownfield redevelopment and regeneration. “Making Places”also aimed to: demonstrate commitment to regenerate the communities in which we operate; It highlights the importance of place making and creating better futures; and linking the past with the future (students) through the medium of photography, which was chosen for its accessibility and ability to capture a moment in time. The concept was further developed in collaboration with WERK, an award winning contemporary arts organisation that specialises in projects that re-frame the relationship between art, the built environment, communities, and audiences. WERK provided consultation on how to outreach to secondary schools across the UK. Running in tandem with St. Modwen Corporate Social Responsibility team, it suggested that a professional practice project would enhance GCSE art students’ coursework and encourage schools to partake. Following this advice, the campaign was focused on students from schools situated near one of brownfield regeneration projects to capture the theme of place making through photography. The purpose of Making Places was for students to gain a sound understanding of St. Modwen’s brownfield regeneration aspirations and in turn, explore what community, architecture, or urban design means to them. The aim was to inspire, excite, and support

Students from Colmers Farm School explore the regeneration of Longbridge Town Centre, Birmingham the next generation on a subject matter that impacts everybody and at the same time, enhances students’ photographic skills and gives them access to industry experts. Not only is photography an excellent communication tool but it also proved a means to engage closely with the public by actively involving the students with our brownfield developments while encouraging creativity and learning. By engaging with students, the campaign also helped educate a new demographic about the importance of regenerating brownfield spaces into places that can make a positive and genuine change to the communities, the environment, and economy.

Capturing a new audience GCSE students from 30 schools wew invited across England and Wales to take part in the competition. A toolkit showcasing the timeline, objectives, participation requirements, and outcomes was shared with each school. Social media was used to post photographs, created and published newsletters to give tips, and made regular phone calls to maintain momentum and engagement with both teachers and the students from each school. The participating schools were invited to attend a workshop run by St. Modwen at its local brownfield regeneration project, which also formed the basis of their subject matter. During each workshop, Stephen Burke, from WERK, and photographer for the Financial

Times and Telegraph, provided support and guidance to the students. We saw this as an opportunity to encourage career opportunities within photography and the arts, as well as giving students an insight into photographing architecture and the built environment. In order to produce a creative and innovative piece of work, the students also had to really understand the process and benefits of brownfield regeneration. This included learning about the challenges posed by redevelopment of land formerly occupied by heavy industry including engineering contamination and ecological constraints. This provided a platform for the students to gain an appreciation of how St. Modwen creates environmental betterment and diversity. Representatives from St. Modwen also gave an overview of the development site, its history, and future plans. This provided an opportunity to talk with the students about the importance of brownfield

The sudents had photographed a variety of St.Modwen sites


Best Public Participation (including use of visualisation)

Brownfield Briefing Awards 2017 | 17

redevelopment and the long and short-term benefits of regeneration to the local community and economy.

What they said

Finding the winner

The students said:

The competion was launched following the schools coming on board. The judging panel comprised industry experts and were specifically selected for their expertise in education, place making, or photography. “Making Places” was designed to encourage students to appreciate and critique others’ work as well as their own; so, following their workshop, the students were asked to put forward one photograph that best demonstrates his/her exploration of place making. Each school was then encouraged to hold an end-of-term exhibition which created an opportunity to celebrate the students’ work and provided a platform for the winning photograph to be selected to represent the school going forward. From the 30 school submissions, St. Modwen’s directors, along with Stephen Burke, selected seven finalists, representing the seven geographical regions. The seven finalists attended an award ceremony that comprised a place making workshop hosted by Farrell’s architecture practice. The workshop focused primarily on the strategies employed in the design of developments on brownfield land to enhance the local communities and provide better futures. This was followed by an awards reception at the Prince’s Foundation for Building Community’s offices in London, where the work of all finalists was displayed. The overall winning student, as voted by the judging panel, received a professional camera and the winning school received a cheque for £3,000 to be spent on the school’s art department. Each finalist received a print of their own entry as well as a digital camera. Following the conclusion of the competition, the winner, Ruby Kripps, was invited to take photographs at a St. Modwen event near to her school. She has since featured this opportunity, as well as the competition, in her personal art portfolio.

“It was good to get out of the classroom with my photography group and visit somewhere that we would not normally get access to and I enjoyed the creative challenge that the brief offered. Overall, I found the competition very worthwhile.”

Positive outcomes St. Modwen continues to engage with each of the schools and has installed permanent and temporary displays of the final submissions as well as the highly commended photographs across various development sites. The competition was also featured in its latest Annual Report, CSR booklet, and on its website. This has given an opportunity to engage with shareholders, who see CSR activities as vital components in the business model. During the campaign, more than 400 students took up the challenge. There were

“I loved the workshop as it was an experience I have never done before!”

The parents said: “Ruby wants to go on to study fine art after she has finished her GCSE’s and A levels and winning the competition will add to her CV and portfolio which will help when applying for university places.” “Thank you to St. Modwen for organising such a wonderful day for all the finalists in the photography competition. I went as a parent and had a fantastic time. We loved the Farrell’s tour and the talk was very inspiring. The lunch and presentation was also very good and made all the contestants feel very special.”

The teachers said: “Our department really enjoyed taking part in this National Competition and we were very pleased we had a regional winner. We currently have an exhibition of the students’ photography in the department.” “It has been a fantastic opportunity for the students… to have experienced a live brief. The competition sat very well in line with their current coursework, allowing students to see how photography and visual

more than 31,000 impressions on social media and more than 24 pieces of media coverage, with a reach of 384,425. The feedback received was all positive and has reinforced good working relationships. The students enjoyed broader learning skills and exploring areas they would not normally be permitted to access. This project was conceived to educate future generations to accept and engage with brownfield sites and to understand why brownfield sites are locally, regionally, and nationally important and sustainable both now and in the future, thus helping enhance their acceptance in the local community. The photography competition was an excellent tool in delivering our message about the importance of brownfield regeneration sites, to both the pupils involved in the photography competition,

communication can be used within such an industry and highlighting the importance and strength of pictures as a source of visual communication in the current developing world… To be a finalist for such an outstanding company is rewarding in itself.” “The competition allowed the students to engage, look and appreciate their current surroundings and the development that is taking place… Their thought processes were definitely challenged.”

Ben Bolgar, director, The Prince’s Foundation for Building Communities and competition judge, said: “Placemaking, in creating better places to live, is fundamental to the work of The Prince’s Foundation for Building Community. We welcomed this competition from St Modwen to encourage future generations to think about what it means and how architecture and urban design can improve quality of life.”

Bill Oliver, former chief executive at St Modwen, said: “We wanted to use our 30th anniversary to build on our schools engagement programme and link education with regeneration, art, and urban design. Not only has the photography competition achieved this, but it has also enabled us to capture what regeneration looks like in 2016 to a new generation. The students are growing up with regeneration projects right on their doorstep and the competition has helped them to explore their community and get an understanding of what it is that gives a true sense of place to any community.”

and the community stakeholders around them. These stakeholders include the pupils’ peers, teachers, parents, and the judges – all of whom are likely to have become more aware of St. Modwen’s regeneration projects - as well as the wider public through press coverage and social media coverage of the photos and campaign. Stakeholder engagement was received with competition feedback from the students, teachers, and parents, as well as from third parties online and through social media.

Judges’ Quote: “St Modwen’s innovative initiative encouraged a stakeholder group that doesn’t often get a voice on brownfield matters. This project breaks the mould.”


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19 | Brownfield Briefing Awards 2017

Best Re-use of Materials on a Project

WINNER

Leeds College of Art ORGANISATIONS

WYG Group, Sanctus Ltd, Leeds College of Art

Leeds College of Art is located close to Leeds City Centre, opposite the main entrance to Leeds University. The 0.27ha constrained site comprised an LCA car park that had been constructed in 1985. Planning permission was granted for the construction of a new teaching block. Phase I geo-environmental work discovered a former school on the site that was built in 1908 and demolished in 1978. Architectural records revealed that the school contained two floors of below ground basements, the lower of which included a swimming pool, a boiler room, and heating ducts. The basements were still relatively intact but had been infilled in places with demolition rubble, leaving large voids and a foundational slab 8-9m below ground. WYG designed the proposed building to have a ground-bearing floor slab, to which the voids would have posed a significant constraint. It also proposed piled foundations, the installation of which would have been inhibited by the existing basement structure.

The task at hand Enabling works were required to remove the sub-surface structures and the uncompacted and voided made ground, and it needed to be backfilled to an engineering specification to provide a suitable founding stratum for the floor slab.

There were also several technical issues to address. Firstly, the heating ducts contained pipework that was lagged with asbestos. The basement walls were clad with asbestos insulation board and there were degraded fragments of asbestos containing materials (ACMs) in the demolition rubble. Disturbing this degraded material is classed as licensed asbestos removal works under the Control of Asbestos Regulations 2012. Remediation of licenced in-ground asbestos is a specialist area and not many suitable remediation contractors hold an asbestos licence. WYG led the procurement of the works and Sanctus was awarded the contract. The excavation of several tonnes of highly degraded asbestos was required in a city centre environment, adjacent to housing, offices, and a main road, and the basements extended off-site near offices. Furthermore, an 8-9m deep excavation was required in immediate proximity to one of the main roads into Leeds City Centre, separated only by the pedestrian footway. Temporary works with trench boxes were put in place by Sanctus to complete the excavation safely. Other issues included the gas and water mains crossing the site that required capping and diversion and an 8-9m deep excavation was required in close proximity to the leaning retaining wall. Finally, the project programme was extremely tight and important to the

client. The piling/building contractor took possession of the site immediately after the enabling works contractor vacated the site, which meant that the validation report needed to be provided in a final format within a week of site works completion.

Innovative thinking and adaptation Traditionally, works may have excavated the former basements, taken the material off-site, and imported geotechnically and geo-environmentally suitable material to site for backfilling. That technique was not suitable at this site due to the costs of disposing of large quantities of asbestosimpacted hazardous material; therefore, almost all material used for backfilling comprised site-won material generated from the in-situ mix of historic building materials and made ground. ACMs were handpicked from site-won material or physically stripped from the sub-surface building structure. This practice minimised the requirement for disposal of ACM containing hazardous waste and the cost of importing material - both providing a major cost saving to the client. It also reduced the carbon footprint of the scheme and was a highly sustainable approach. The presence of asbestos is still alarming to many in the industry and particularly to the public. Undertaking a risk-based approach to the asbestos contamination, considering


Best Re-use of Materials on a Project

CIRIA C733 rather than risk averse measures that were unjustified, was therefore considered innovative. Remediation targets were defined and then re-negotiated with the Council during the works using a risk-based approach while still considering the perception of third parties. The remediation strategy that was agreed with the regulator incorporated two different standards for the quantity of asbestos that was acceptable to be present in the back-filled soils. The asbestos gravimetric laboratory test was split between the Stage 2 visual inspection stage (for ACMs and fibre bundles) and the Stage 3 PCOM microscopy stage. The material being placed below 1m was required to show a result below detection in the Stage 2 part of the test, while for the upper 1m of soils (and piling mat), a below detection result for both the Stage 2 and the more stringent Stage 3 test was required. When a sample failed on the presence of asbestos fibres, the remediation target was re-negotiated with the regulator to allow for the presence of fibres at depth, outside of the piling area. On-site screening and crushing of recovered material produced sufficient suitably graded recycled aggregate to construct the piling mat and upper 1m of material containing no microscopically detectable asbestos material.

Brownfield Briefing Awards 2017 | 20

the material that was re-used in the ground had been so thoroughly processed that only 100m³ was recorded as containing asbestos fibres. That material was placed at depth by the ground-bearing slab to minimise disturbance. The contract was written in such a way that the savings from minimising off-site asbestos disposal were shared between LCA and Sanctus. This provided an added incentive for the contractor to recover it. Critically, given the city centre location, maximising material re-use on site saved about 1,850 lorry movements compared to a disposal and import option. There was no turning space for HGVs on-site, which meant any HGVs would need to have stopped the traffic to enter the site; this could have increased traffic on an already congested main road.

Application to other works The sub-division of the gravimetric test, using the Stage 2 part to confirm the absence of ACMs, is a technique that can be easily used elsewhere. Simple and welldocumented controls such as laboratory testing of processed material provide regulator confidence, which aids approval. Using Stage 2 only of the gravimetric test provides confidence to third parties such as landfill operators that material does not contain ACMs. Given that the presence of only one piece of ACM can classify a whole waste stream as hazardous, the removal of all the ACMs is critical. Therefore, these techniques are very cost effective. Handpicking of soils is a commonly used technique. However, this project also combined licenced asbestos removal from a building to a below ground, highly constrained environment. The uploading of site data to a shared cloud server on a daily basis to aid real time checking was also effective and could be cost effectively applied to other projects.

Sustainable re-use of materials The material in the ground at the start of the project contained substantial quantities of degraded asbestos. At the end of the project,

Re-use of excavated materials under the CL:AIRE definition of waste CoP By the end of the project: n 8,035m³ of material was excavated and broken out n 120m³ of tarmacadam was taken off-site for re-use n 10m³ of excess oversized concrete was taken off-site for re-use n 70m³ of topsoil was taken off-site for re-use n 9.7t of asbestos contaminated waste was disposed n Only 0.1% of soils were disposed of at landfill (10m³) n 97.4% of material was re-used on-site (excluding asbestos waste) and 99.9% was re-used or recycled.

Variations to the geotechnical specification To facilitate material re-use and increase the speed of backfilling, the specification

for the engineered fill was varied on several occasions during the works. The areas for the allowable re-use of different classes of material were relaxed to maximise material re-use while still meeting the engineered fill requirements. The plate loading requirements were also relaxed once the performance of the material and the suitability of the contractor’s methodology had been demonstrated, which meant Sanctus didn’t need to frequently stop works to wait for testing to be carried out. A key reason why the asbestos from the site was collected and not dispersed into the soils is because of the standard of the site works. Insulation board and ACMs could be handpicked from the excavated material prior to screening and crushing but it was the licensed asbestos removal from the ducts that was key to the success of the works. There were large ducts around the swimming pool that contained pipes with degraded lagging. Asbestos fibres from the lagged material and a spray coating covered the internal walls of the ducts. The ducts were approximately 3m below ground level. The contractor could have removed the soils from above the ducts, broken out the top of the ducts and then entered the ducts from a lowered surface to remove the lagged pipework and the asbestos on the walls. However, to have done so would have mobilised quantities of asbestos fibres into the air and impacted the surrounding material and increased risk. This posed a high risk to the aim of minimising fibre impact. Sanctus therefore undertook a structural integrity survey of the ducts and, despite them being approximately 100 years old, it concluded that the lowest risk was for personnel to enter the ducts, clean the asbestos off the walls, spray the pipework with water-based glue to minimise airborne fibre generation, wrap the pipework in multiple layers of plastic sheeting, and then remove the pipework in sections (without cutting it as this would have mobilised fibres). An angle grinder was used only to cut the fixings. The pipework was then placed into a sealed skip and taken off-site for specialist disposal. Approximately three sections (75m) of ducting was treated this way, with qualified Sanctus staff fully suited in PPE/RPE and all the requirements of licensed work in place. Judges’ Quote: “This project demonstrated very high levels of materials re-use and recycling under a tight schedule and on a constrained city centre site. It showcased an exemplary approach to the two hot topics of material re-use/minimisation of off-site movements and tackling in ground ACMs.”


21 | Brownfield Briefing Awards 2017

Best Science/Laboratory Advancement

WINNER

Light Non Aqueous Phase Liquid (LNAPL) Automatous Monitoring System ORGANISATION

Ecologia A baildown test is a seemingly simple method to measure LNAPL mobility. However, the interface probes used are not very precise, the tests can be very long and a small part of human error can change the result quite significantly. Ecologia has found an innovative way to get around these problems, by developing a LNAPL Automatous Monitoring System.

Synopsis The key recoverability criteria for free-phase Light Non Aqueous Phase Liquid (LNAPL) in contaminated soils is its mobility, expressed as transmissivity. Following the publication of the CL:AIRE LNAPL guidance in 2014, it is now more understood that significant thickness of LNAPL can be present in a well, but that this does not mean that meaningful quantities of LNAPL can be recovered. The characterisation and assessment of the risk that may be posed, and the ability to recover a free-phase LNAPL are all dependent on a robust understanding of the behaviour of the LNAPL and the factors that may affect this. The metric is transmissivity, which is an expression of the mobility of the LNAPL. It integrates the relative permeability and physico-chemical characteristics of the LNAPL and the nature of the soil. Whilst measuring the mobility of the LNAPL is conceptually straightforward, it is practically less so. A number of methods exist, but the most common and practical method is a baildown test. This involves instantaneous removal of the free product in the well when it is at equilibrium with the formation, and then measurement of the recharge over time until equilibrium is again reached. The interfaces of the LNAPL between the air and the water are recorded using an interface probe, which requires that an operative is present throughout the test. Essentially, a gradient (called the drawdown) is created in the LNAPL, and the plume’s response to it is then measured. The data from the test is then applied to an equation, and a figure for the transmissivity is produced. However, in some conditions, particularly when the mobility of the LNAPL is quite low,

the recharge of the well may take a number of days or even weeks. It is not practical or possible in these cases for an operative to take manual measurements – the well may be at an active, high risk site, for example a train depot or refinery, where access to wells is contingent on the operation of the site. This can be a particular problem if the well has confined or perched LNAPL. These are conditions where the LNAPL is trapped underneath, or is resting on the top of a low permeability layer, such as clay. These conditions are often found at refineries build on floodplains where there can be complex geology in the vadose zone. The LNAPL recharge in these wells behaves differently to non-confining conditions, but this may not be apparent until after several hours - after any operatives have left site. A final problem lies with the interface probes themselves. There may be inconsistencies in measurement caused by for example, twists in the tape, and if extended periods of monitoring are needed overnight, then fatigue can become an issue for the operative, leading to misreadings. Different operators also have different small biases when measuring. These can errors can become compounded, and lead to a large margin of error in the final transmissivity value. Additionally the need to have operative present on often high risk sites, for prolonged periods of time increase the health and safety risks.

Scientific problem The problem lies with the ability to measure two interfaces simultaneously in the field. Conversely, for a well containing only water, this is simple. A data-logging pressure transducer (‘diver’) can be used to record the total fluid head, consisting of the mass of water and the mass of the atmosphere. In combination with barometric diver, the effects of the atmosphere can be accounted for. When LNAPL is present in a well, there is no method to identify the location of the water- and air-LNAPL interfaces: only the atmosphere can be accounted for. As the LNAPL moves in the well, more water is displaced, and this pushes the

water level down. The LNAPL is generally of a density of 0.7g/ml to 0.99g/ml (by definition), and so the extent to which the LNAPL will displace the water is specific to any given LNAPL. As the LNAPL increases in thickness, it may pass over zones of soil where the permeability is significantly different (confining or perched conditions), and so the rate of recharge may not always decrease with decreasing drawdown. Figure 1 shows the geometry of an idealised well, and the best current method of measuring fluid head using divers. A number of researchers have attempted to simultaneously measure the two LNAPL interfaces in the field. The most notable were efforts to use sonar and pressure-

Figure 1. An idealised non-confined well showing a thickness of LNAPL in a well. There is no current method to infer the location of the airand water-LNAPL interfaces, and they must be measured by hand using an interface probe. sensitive tape for the top LNAPL level, with divers used to measure the total fluid head. The water-LNAPL interface was inferred from the data. However, these techniques used three separate measurements (in-thewell and barometric divers, and air-LNAPL interface monitoring), which each had their own measurement error. When combined to give interface levels, they were too ‘noisy’ to be of practical use.

Solution Ecologia’s system is automatous and uses a guided wave radar sensor to measure


Best Science/Laboratory Advancement

Brownfield Briefing Awards 2017 | 22

the fluid interfaces, without the need for diver data. This provided a much cleaner signal and avoided the requirement for multiplication of measurement error. The guided wire radar sensor is also energy efficient, so can be powered by a 12V battery. A full charge on a 72Ah battery lasts around 550 hours, or over 22 days.

Figure 3. A typical echo curve from the sensor. Two distinct peaks can be seen. The sensor also picks up false echoes, which it is programmed to ignore, and has a dead zone in the first 30 cm of the well. However, it is uncommon to find fluids at this shallow depth.

How it works A guided wave radar works by sending a weak an electromagnetic signal down a metal conductor. If the conductor passes through a substance that has a different dielectric constant, this causes some of the signal to be reflected. The dielectric constant of air, LNAPL and water are all different. Air is around 1, LNAPLs are typically around 2 to 3, and water is around 70. The air is ignored by the sensor as a background constant, but the sensor can pick up the change from air to LNAPL, and from LNAPL to water. These signals are then decoded by the sensor, and the interfacial levels are given as outputs. This technology is known as Time Domain Reflectometry (TDR), and is generally used for soil moisture measurement. The data can then be used to monitor changing LNAPLs levels, most importantly during the potentially long LNAPL recharging stages of a baildown test.

substitute for LNAPL, in the first instance, and then diesel was used to replicate site conditions as closely as possible. The set-up was found to be able to accurately and precisely track levels of the diesel and water as they were manipulated under laboratory conditions. There was a remarkably high degree of accuracy and precision. The artificial well was a clear permeameter and so the LNAPL could be measured using a tape measure, and any issues of the interface probe avoided. In these tests, the sensor was set to record the levels once every minute. In the overnight test, 935 readings were taken over 15 hours. The greatest variation in reading for the water level was 1.125 mm, for the LNAPL 0.975 mm, and for the recorded thickness of the LNAPL - 0.75 mm. It is not possible to produce data of this resolution with an interface probe.

Field trials

Figure 2. The theory of measurement for the radar sensor. By measuring the time (hence Time Domain) a signal takes to return (Reflectometry) the device can calculatethe location of the air- and water-LNAPL interfaces.

The sensor records data in two different ways. It can save what is known as an ‘echo curve’ which is the graph of the TDR, and it can record data points, where the sensor takes an estimate of the levels. The echo curves allow the data points to be independently checked and if needed, corrected.

Laboratory Trials Initial trials were conducted in Ecologia’s laboratory. Vegetable oil was used as a safe

A site was identified where there was significant thickness (up to 900 mm) of LNAPL present in some wells. The monitoring wells had not displayed any LNAPL after drilling, but aged diesel migrated into them between weekly monitoring after around six months. The thickness of LNAPL in the wells then varied from week to week. A baildown test was carried out to measure the mobility of the LNAPL, with the result to be used as a tool to decide the most appropriate course of action. The radar system was set up to monitor the LNAPL levels immediately before and after the test, and left in place over several days to record the recharge of the LNAPL back into the well. The sensor was set to record the interface levels for 15 minutes before the baildown test took place. These showed a mostly stable LNAPL. The water level fell around 2.5mm over the course of the monitoring, and the LNAPL level around 1.2mm. An interface probe was also used to record the LNAPL and water levels. The results were consistent with the radar sensor. These data are a combination of echo curve interrogation and sensor-interpreted levels.

The data gathered was appied to the Bouwer and Rice (1976) modified equation for the calculation of transmissivity. It was found that the transmissivity of the LNAPL in this well was 0.003 m2/day. This is far below what is hydraulically recoverable. Figure 3, shows a typical echo curve. These were generated by the device and then later interogated. The data was corrected against them.

Conclusions Ecologia designed and built a system to automatically track two moving interfaces, without the need for a constant operative presence. The system produces higher quality and more robust data than the use of an interface probe would allow. The data are repeatable, less prone to error, and the system can run over the course of several days without outside agency. The system can be deployed and left in-situ to collect repeatable, more robust, high quality near continuous data, without the need for operatives to spend extended time in the field. This reduces uncertainty, provides increased confidence associated with the data collection, and minimises the associated health and safety risks with being on-site for prolonged periods.

Future work Future work for the system will include monitoring of more complex sites with wider ranging temporal affects such as tidal sites, and developing updated well mountings and software. It is anticipated that the device will also be used in site characterisation to support risk assessment and remediation technology selection, based on a solid understanding of the LNAPL behaviour on any given site.

Judges’ Quote: ‘‘In a category described by the judges as the most educational, Ecologia’s project stood out as being both novel and substantial. They believe this useful instrument should have a wide application in the sector.“


23 | Brownfield Briefing Awards 2017

Best Digital Innvovation

WINNER

Former House Estate, South East London ORGANISATIONS

McAulife, Higgins, Notting Hill Housing Building Information Modelling (BIM) is now a familiar tool in design offices and limited site offices, but it has been slow to make an impact on the actual remediation process, at the ‘coal face’. McAuliffe, working with Higgins Construction and Notting Hill Housing, delivered a complex asbestos remediation project in the heart of London with BIM built into the complete design, remediation and reporting process.

The site In spring 2017, McAuliffe was appointed by Higgins Construction Ltd., on behalf of Notting Hill Housing Association, to conduct remediation works on the site to deliver a final engineered development. The site was formerly the council-owned House Estate in South East London, which was demolished in 2005 and had remained unused and derelict ever since. During the SI for the new development, asbestos containing materials (ACMs) and asbestos fibres were found in demolition waste dating back to 2005. This asbestos was only reported present in pockets and isolated areas. A further round of SI included 301 trial pits and 602 environmental samples in a grid across the area of asbestos contamination. This was limited to the top 1m of ground across site, split into the upper and lower 0.5m. Using the grid, the scope of works was defined based on a probabilistic approach to the presence of asbestos, using the relevant concentration of ACMs and/ or asbestos fibres. Each grid was classified as inert, non-hazardous or hazardous (see below). This project was one of the first

Figure 2 - Excavation Grid (treatment areas in red)

Figure 1 - The site to use the JIWG decision support tool published as part of the CL:AIRE CAR-SOIL guidance document.

construction of the piling mat, which was underlain with a geogrid membrane for added strength.

Scope of works

Innovative thinking

Following deployment of McAuliffe’s environmental permit and close consultation with McAuliffe project engineers, full regulatory sign-off was achieved via the Environment Agency permitting department. A fully declared and accepted MMP was also produced following the CL:AIRE DoW CoP. To enable the 10,000m3 of asbestos contaminated demolition material (ACDM) to be reused, a series of remediation works and reassurance testing was arranged. This was based on the classification grid in the remediation strategy, assisted by the use of 3D GPS-enabled plant. In accordance with CAR-SOIL, the ACDM was excavated on a grid-by-grid basis, each grid being uploaded to the excavator. All the material was excavated and visually screened in 100mm layers. Depending on the results of the site investigation, the material was sent directly off site as hazardous, picked on site to remove cement bound asbestos where visible, used as fill below the cover layer, or, if tested, as asbestos free material (<0.001% by mass) for processing into a compliant 6F2 material. Finally, underlying soils were subjected to a turnover to remove relict hard structures. This included lift shafts, concrete piles and relict footings down to 4m. Backfilling and general compaction, using a roller, led to the

Full machine control was implemented on site. Highly accurate, fully integrated GPS receivers were fitted on each excavator and dozer. These were linked to sensors on machines that determined where the bucket or blade was located to +/-10mm (x,y,z) anywhere on site. In order to gain the required GPS accuracy, a base station was set up on site at a known point. Each machine was calibrated and included an allowance for different buckets on the excavator. Each morning the calibration was checked on a known point. When approached at tender stage with the task of controlling an excavation on a 5mx5m grid in 100mm layer, McAuliffe knew full machine control was required. A 3D AutoCAD model was built to include the grid, along with the contamination type, location and depth which was loaded onto the excavators’ CPU and displayed on an in-cab screen. This allowed the driver to know exactly which grid square they were excavating and which route the contamination had to take for treatment. The system could record the as-built data as the excavation progressed, removing the need for repeated surveys. This was monitored from a live internet 3D site link. In this way, the performance and productivity of each piece of plant was tracked in real time from a remote office.


Best Digital Innvovation

Initially, it was assumed that the level of skill from the operator would diminish as the excavators and dozers had auto-dig functions. The opposite proved to be the case, as the operators, freed from the most routine functions, were upskilling and taking on more of an engineering and remediation role. They had to interpret the drawings on their cab displays, understand layered information and remediation management, record as-built information and code each survey point (existing pile, final dig level etc.) correctly.

Useful transfer of technology from other areas GPS technology has long been used for site surveying and setting out, but this has remained in the hands of the professional engineer with limited use. The use of intelligent machines in construction is slowly progressing on road and rail construction, but its use on remediation projects has been limited. McAuliffe takes the development of software and remediation systems very seriously, investing in excess of £500k on systems and plant. It has taken this forward by interpreting the remediation required, and, with its bespoke software and in house design, prepared a digital constraints and construction model to maximise the application of GPS technology. Supported by plant and technology providers Komatsu and TopCon, McAuliffe is rolling this process out across all of its remediation schemes.

Potential for widespread use The potential for widespread use is extensive, applicable on all sites where excavation or filling is involved under a Materials Management Plan. Complex 3D site investigation data can now be used to its full potential. The machine can follow highly complex dig profiles and the location of different soils types, with its movement digitally managed and recorded. At setup, the base station must be accurately surveyed and machines calibrated. Once trained, the system can be operated solely by the plant operators on site, with the option of remote access to the machine’s CPU from the office to monitor performance. By its very nature, GPS offers worldwide coverage, making the system suitable for overseas and remote locations.

Demonstrable achievement of time or cost efficiencies Combining the asbestos remediation, obstruction removal and earthworks solution into a single AutoCAD constraints and construction model enabled a 40%

Brownfield Briefing Awards 2017 | 24

programme time reduction, and ability to deliver the project in less than 12 weeks. This included a complete excavation and compaction exercise to remove underground obstructions up to 4m deep within a very tight working space. The greatest improvement over traditional site controls was the speed of work. With no setting out or waiting for an engineer to supply line and level, the works were progressed unhindered. There were no issues with profile boards or ranging poles being damaged or obscured. One unforeseen benefit was the ability to move work areas at short notice without the need to setup traditional site controls. If one area contained unexpected asbestos, the excavation could be relocated instantly to a safe place, allowing work to continue while the asbestos removal team stepped in to handle it. McAuliffe was able to manage a full audit trail of soils from excavation and quarantine to validation and reuse on site, all managed in real time. The removal of the setting out engineers from the excavation area made the operation inherently safer. The cost of purchasing the intelligent plant and training operators is predicted to be recovered multiple times over the investment cycle of the plant.

Enhanced data capture, storage and accessibility Data capture can be taken to extraordinary detail if required, and data management is a key aspect of the process. By way of an example, the intelligent dozer can capture x,y,z data through its tracks in real time. Data capture is used in bursts and managed to build up a sensible, as-built picture, surveying all formation levels and each 200mm fill layer during re-compaction, with the location of old piles and any obstructions left in place. The data can be sent via sitelink back to the office in real-time or transferred via USB flash drive where mobile data links are not available.

Significant contribution to QA/QC Quality is improved in the following ways: n By uploading the locations of underground services, or ‘no dig’ areas, onto cab screens, operators avoided these areas, thus greatly reducing damage to services n The UXO medium risk area was identified on the cab screens. This allowed workers to avoid these areas, unless there was a UXO supervisor in attendance n A full, real-time audit trail of excavated soil through quarantine, re-sampling and re-use was produced, with all record time and date stamped

n Operators were no longer waiting for setting out engineers, so didn’t continue working outside traditional site controls n Completed work could be surveyed instantly with a digital date and time stamp n As-built information, such as old pile locations, was sent in real time to the design team building the new development. This way, they could relocate new piles that may have clashed with old ones n Comprehensive validation reports were produced on completion with no delay. n Surveying staff and personnel were removed from working faces and potential asbestos risk areas n Machine operators were upskilled to have a proactive role in the remediation process.

Key innovations In conclusion, key innovations included: n Taking the client’s model and digitally processing this data into a suitable format to upload to machine control for excavators and dozers n Providing volumetric analysis of materials movement n Using machine control to precisely excavate areas of asbestos impact n Removing site setting out and improving safety by allowing engineering staff to monitor progress remotely n Avoiding below ground service strikes, as operators could view services on the cab screen. These were created as ‘no dig’ areas in the model n Upskilling plant operators to include understanding of the remediation process and final deliverable site layout. n Using machine control to produce real time, as-built survey data relayed in real time through 3D sitelink. A genuine breakthrough of real value to the sector. One of the true tests of adopting a new technology is “can you see yourself living without it on the next project”? Well, in the case of BIM and intelligent machine control, the answer is a clear NO from all those involved on site. This technology is integral to the success and efficient, safe delivery of all projects.

Judges’ Quote: “McAuliffe’s winning entry demonstrated the effective use of digital technology, such as BIM, to control excavation works on a remediation site. The approach was very carefully guided by the use of digital technology, yet it was translated onto a real site.”


25 | Brownfield Briefing Awards 2017

Best Urban Regeneration Project

WINNER

Waters Keep - Goscote Lane Corridor Regeneration Area, Walsall ORGANISATION

Walsall Council, Walsall Housing Group, Keepmoat Homes Goscote Lane Corridor consists of two key development sites – Waters Keep Phase 1 and 2 – where over 800 new homes of mixed tenure and type are under construction. As well as creating modern homes for residents, the project is about investing in people and improving lives in order to achieve sustainable long-term change in the area. Through the HCA Development Partner Panel, Walsall Housing Group (whg) has separately procured Keepmoat as the preferred housing partner for Phase 1 and 2. whg and Keepmoat began the £45m Waters Keep development in November 2014 and will deliver 412 new homes by 2018, comprised of 177 affordable homes and 235 units for private sale. To date 340 homes have been completed on Waters Keep. The final £56m development phase is due to begin in summer 2017 and will consist of 426 homes, 279 of which will be for private sale and 147 affordable units, including a 40-unit wellbeing apartment scheme with communal facilities, 31 bungalows for people aged 55 years and over, and 76 general needs family homes for rent. It is recognised that one of the biggest challenges for housing-led regeneration is that projects move in and out of viability as the housing market fluctuates. The partnership of whg and Walsall Council has however been able to provide the long-term commitment and patient capital needed (whg), together with external funding, to sustain regeneration and development despite the viability challenges. The project is also a clear example of how regeneration can be delivered in lower value housing market areas with the right approach. The development is already proving to be one of Keepmoat’s most popular nationally and a key element of this success has been the attractive pricing of sale properties in a local market context.

Regeneration strategy The regeneration is being delivered thanks to a partnership between whg and Walsall Council. As a stock transfer and major landlord in the area (owning around

20% of the stock in Walsall and housing around a quarter of the population), whg has historically strong ties with the local authority. Shortly after the transfer, Goscote Lane Corridor was recognised as a transformational project within the Walsall Strategic Regeneration Framework (SRF) in 2007, a 10-15 year blueprint for planning, investment and comprehensive housing-led regeneration in Walsall to achieve social, economic and environmental outputs. Recognising their combined regeneration responsibility, expertise and asset holdings, Walsall Council and whg set to deliver this shared regeneration aim through a commitment to partnership working, trust and openness, and shared solutions. Goscote Lane Corridor (area outlined in red on the above plan) is approximately 1.5 miles north of Walsall Town Centre and less than a mile east of Bloxwich District Centre, and is predominantly a residential area with access to open spaces and the Wyrley and Essington Canal. The area also benefits from local amenities at nearby centres, primary schools, as well as Goscote Greenacres community garden and palliative and dementia care health facilities at Goscote Lane. Identified as a ‘failing’ area in the Black Country and Telford Housing Market Renewal area, demolition and clearance of 500+ properties (predominantly semidetached social housing) through voluntary acquisition and relocation took place during 2006-2009 within the regeneration corridor. Through the establishment of a local project steering group, including local residents and key stakeholders, a Regeneration Framework Plan (2007) and subsequent Design Guide (2010, revised 2012) were prepared for the area. The framework set out an ambitious development programme of 800+ new homes across 58 acres of previously developed brownfield land to diversify and rebalance housing types and tenure. The aim was to deliver a high quality local environment focused on key design principles of creating:

n A local identity n Legible streets n Links to the wider community n Streets as spaces n A safe, secure environment n High quality homes

Joint investment These ambitious proposals – Walsall’s largest housing regeneration programme - were set at a time of uncertain economic and housing market demand. Achieving such large-scale comprehensive housing-led development therefore required an innovative approach from whg and the Council, as major land owners, and highlighted the importance of both private and public sector involvement to make the project work. The delivery of the Goscote Lane Corridor is a strategic priority for the Council and whg. It was also a priority for the Homes and Communities Agency (HCA) and the Black Country Local Enterprise Partnership (BC LEP); particularly given its importance in contributing towards housing targets nationally and those set in the Black Country Core Strategy (BCCS) and Strategic Economic Plan (SEP). Through a partnership approach, the land owner partners have been successful in securing public sector grant funding from the HCA and BC LEP who are contributing £2.66m (part of the £12.3m secured by whg under the Government’s Affordable Homes Programme 2015-2018) and £8.82m (Local Growth Fund (Round 1)) to support the delivery of affordable housing and green space improvements.The majority of funding has come from the private sector –


Best Urban Regeneration Project

with whg having borrowed £23.77m for the project and the remaining match funding of £52.16m secured through developer investment and sales.

Resident engagement A key consideration throughout the project has been maintaining relationships with the local community. As a large-scale regeneration scheme, residents were understandably concerned about change and the new community in the area. This has been managed by the partners through ongoing dialogue with residents from the start. From 2007 residents were actively involved in the shaping and design of the Goscote Lane Corridor masterplan and design guide. This included community information days and engagement with local schools. The name Waters Keep was chosen by schoolchildren. A four week consultation was also held in relation to the open space improvements masterplan, with several drop-in events and over 240 feedback forms received, which helped inform the final designs. Since the commencement of the construction works, a Community Action Group (CAG) has been launched and continues to run. It is made up of local councillors, residents and representatives from whg and the Council. This group continues to meet regularly to give their

feedback and resolve concerns. Through the CAG, whg launched a newsletter, WS3, which was delivered to around 4,000 residents to keep them up to date on the latest developments. Two community champions have also been appointed, both to liaise with residents on the regeneration and to support new and existing residents into work.

Economic, social and community benefits As part of the project, the partners have sought to maximise the direct social impact of the regeneration. The development agreement delivered by whg and Keepmoat outlines a number of added value commitments including the creation of 48 apprenticeships and 40 traineeships, support for 32 local businesses and maximising use of the local supply chain. Apprenticeships, traineeships

Brownfield Briefing Awards 2017 | 26

and jobs have been provided in construction, administration, catering, and environmental/ green space management. Training is also aimed at helping people secure better quality jobs and improved incomes, for example by providing guidance to residents about the risks of zero hours contracts. The Council has also acted as delivery partner for the open space improvement works which aim to support market attractiveness and the high quality environment aspirations for the area. The open space areas and canal corridor, which are central to the housing development phases, have benefited from £1.3m Local Growth Fund investment with improvement works having completed in May 2017. The area was previously low quality grassland with limited use for informal recreation and weak linkages and integration with the surrounding residential areas. The open space improvements have transformed the area, providing good connections to open space and much needed community resource to encourage local cohesion and positive interaction between both existing and new residents and promote health and well-being opportunities for people of all ages. The works have included new paths, site furniture, fishing pegs, trim trial routes, football pitches, together with formal play areas, multi-use games areas and skate facilities. Working with Walsall Public Health, whg has also delivered health and wellbeing interventions in the regeneration area. This has included lifestyle advice such as weight-loss and stop-smoking programmes. These have resulted in an increase in referrals and access to mainstream services, a rise in the number of outreach services available and improved links and referral pathways between provider organisations. Through the provision of an overage agreement and shared aspirations held by the Council and whg, the project will continue to see further regeneration investment in the area; with the overage share from the development due to be paid into VIEW (Visionary Investment Enhancing Walsall) and used to support joint priority community infrastructure projects within the vicinity of the development sites.

Environmental sustainability Although the preferred construction of the dwellings is traditional load bearing masonry, Keepmoat is committed to reducing carbon emissions through the use of highly insulated external envelopes and greater water efficiency. As part of the scheme delivery across the various sites it is a contract requirement

that all the affordable homes properties meet Code for Sustainable Homes at Level 3, with the remainder of the private sales units meeting Building Regulations. The sites will also benefit from Secured By Design accreditation making the individual properties and the local area a safe place to live. As part of the CfSH, the developer operates within a Waste Management Strategy, which looks to reduce waste as much as practically possible and to ensure that when it is generated, it is segregated so it can be taken-off site for recycling. To comply with current drainage requirements the major sites uses a Sustainable Urban Drainage System (SUDS) either in the form of an infiltration basin or retention pond. The systems capture the surface water drainage to ease the pressure on the mains drainage and providing an environment for local flora and fauna to flourish. To enhance and protect the local wildlife, ecological surveys were undertaken prior to start on site. In consultation with the local authority steps have been taken and enhancement measures introduced, such as wildlife corridors on the boundaries of the site where they meet existing open spaces or water courses to create buffer zones between the two. Materials and labour are largely sourced locally which not only reduces the impact on the environment but also stimulates the local economy, which in turn will create local jobs for local people. whg and Keepmoat ran ‘Meet the Supplier’ events at the start of the scheme to encourage local suppliers and trades companies to register their interest in working on the project.

Supporting information Links to Drone Flyover footage by Ginger Innovations showing construction progress: June 2015- https://www.youtube.com/ watch?v=Z45PG08jzLk October 2015- https://www.youtube.com/ watch?v=S2Xdj1NHh_g March 2016- https://www.youtube.com/ shared?ci=1OfMzfFP0Xk June 2016 - https://www.youtube.com/ watch?v=fwX34I46vJQ December 2016- https://www.youtube.com/ watch?v=kBWy-U0rYYo Judges’ Quote: “The winning entry was not just about economic regeneration, it was also about social regeneration and sought to improve community well-being. It provided new green space, unlocked the site for future development, and altered perception of a previously blighted area.”


27 | Brownfield Briefing Awards 2017

Best Brownfield Infrastructure Project

WINNER

Drainage Network - Glan Llyn, Former Llanwern Steelworks, Newport, South Wales ORGANISATIONS

St. Modwen, PJA Engineering, Rodgers Leask Ltd, Prosurv Consult Glan Llyn is a 35-year brownfield regeneration project led by St. Modwen and located near the city of Newport in South Wales. It occupies the site of the former Llanwern Steelworks and comprises 240ha of former derelict land to the north of the Gwent Levels SSSI, some two miles inland from the Severn Estuary. The Llanwern Steelworks was built in 1962 for Richard Thomas and Baldwin and was later bought by British Steel to run as a sister operation to their Port Talbot Steelworks. Llanwern was the first oxygen blown integrated steelworks in the UK and, at its peak, produced a combined 4m/t of steel/yr with Port Talbot, indirectly employing up to 30,000 people. The vision is to transform the Llanwern Steelworks into Glan Llyn, a residential development supporting mixed use and employment land-uses. The re-developed site will provide 4,500 homes for around 12,500 people and will include two schools, community facilities, retail areas including a supermarket, public open space, as well as a 42 ha business park providing 6,000 permanent jobs for the local community. The dwellings form a key housing allocation in Newport City Councilâ&#x20AC;&#x2122;s Unitary Development Plan. Following St. Modwenâ&#x20AC;&#x2122;s purchase of the site an active reclamation and remediation programme began in May 2008. The delivery team comprises St. Modwen - land owner and developer; Prosurv Consult Ltd procurement and contract, programme and cost management and PJA Engineering Ltd and Rodgers Leask Ltd - engineering design.

Impacts on the Gwent Levels The site originally formed part of the Gwent Levels managed through the millennia as lowland summer pasture. The fields were criss-crossed by steep-sided drainage ditches known locally as reens. The development of the steelworks led to the destruction of the historic drainage system and the imposition of an industrial

network which fundamentally altered the character and natural flow dynamics. Surface water flows from the site no longer discharged to the Gwent Levels. This not only affected water originating from within the site but also inflows from pre-existing water courses from the north, all of which were captured and pumped via aging pipelines directly to the Severn Estuary sea outfall. The net effect of industrial development was dramatic and included: n Culverting around 90% of the natural reen system n Virtual eradication of the natural fauna and flora and a significant reduction in biodiversity n Removal of any amenity value n Increased flow rates through the site creating increased flood risks downstream n Degradation of water quality through industrial discharge and leaching of contaminants from slag material (exacerbated by the removal of the attenuation capacity of the vegetated reen system) n Artificial lowering of the groundwater table

Masterplan vision As part of the restoration and remediation of the site the masterplan envisaged re-opening up the reens to provide simple drainage conduits within the new urban landscape. During the detailed design phase, it also became apparent that rather than acting as simple conduits to larger water bodies the drainage network could act as a multifunctional system. This multi-functionality provided alternative approaches to flood storage, water quality management and biodiversity enhancement as well as enhancing the landscape. The design challenges associated with re-creating the drainage system have been significant. The original design envisaged the continuing use of gravity flow to the industrial drainage network to the south

of the site. This option became undesirable as this network remains in use by Tata Steel and requires flows to be managed through an industrial discharge consent and had limitations imposed by the pumped sea outfall. An alternative scheme was devised utilising an existing channel, the Monks Ditch, which has direct access across the Gwent Levels. Although advantageous in allowing a more natural drainage route the Monks Ditch bisects the site and was wholly isolated in a raised channel. This option also required a detailed re-evaluation of flood consequences and water quality management given the direct access to the Gwent Levels SSSI (as opposed to the direct sea outfall).

Flow and flood modelling A complex modelling exercise was conducted on the Gwent Levels fluvial system over many months to assess the response to rainfall and storm events. The modelling demonstrated a limited capacity to take additional flows within Monks Ditch and the Gwent Levels during severe storm events. A maximum design flow from the site was calculated at 3.5l/s/ha. Given Glan Llyn is lower than the Monks Ditch all water has to be pumped to enable discharge. However, it is only possible to pump at the minimum rate during the summer months with capacity for out of season pumping only possible when the water level within Monks Ditch is low and with the tide lock to the Severn Estuary open. The 1:100 year storm event (plus climate change) was used as the basic design parameter together with the assumption of two back to back 1:5 year storms. However, to provide a level of insurance the site drainage system is designed to accommodate an entire month of rainfall, with limited pumping. In addition, the site has to accommodate 50,000m3 of surface water from the existing flows entering the site from the north.


Best Brownfield Infrastructure Project

The consequence of these design limitations is the need for a vast 350,000m3 of water storage within the site. This is equivalent to several free standing reservoirs, all of which need to be accommodated discreetly between the maintained water level of 3.4m and the lowest breach flood level of 6.3m AOD. To avoid the creation of large areas of standing water the storage volume is to distributed over network of the re-created reens.

Stakeholder involvement Stakeholder engagement as part of the design was critical in delivering a solution that understood the ancient water system and avoided contributing to flood events across the Gwent Levels. Natural Resources Wales were particularly interested in the ability of the downstream features in the Monks Ditch (weirs and control gates) to withstand storm events without being overwhelmed. In consequence telemetry was installed at critical points to support the model. The model assessed 17 downstream features. By utilising the data from these downstream control points the delicate balance between the surface water on site, water in Monks Ditch and the Gwent Levels was assessed. The modelling, whilst allowing on-site storage capacities to be assessed, also helped to define maintenance and upgrade requirements at each of the 17 water control features within Monks Ditch. Improvements undertaken by St. Modwen ranged from simple vegetation clearance to complete re- construction of weir features and the installation of additional telemetry. The on-going use of telemetry will help fine-tune the discharge criteria during the early years of operation to ensure that when the site is fully developed the theoretical design calculations are calibrated with real time data.

Water quality The designed system also forms an integral part of the treatment train to manage water quality variations. Surface water quality across the site was variously impacted by hydrocarbons, polyaromatic hydrocarbons and metals. High pH, typically up to 13, had also sterilised many of the reens making them unfit for inclusion within an urban environment. The high pH was the result of hydration reactions between calcium and magnesium oxides within the steel slag at the site. Excavation and stabilisation of the slag together with isolation from the new reen system has allowed the beneficial re-use of

Brownfield Briefing Awards 2017 | 28

this material around the site. To manage the residual concerns of National Resources Wales (NRW) a site specific controlled waters risk assessment was undertaken using the parameters from the drainage modelling to assess the likely concentrations of contaminants to; a) on-site in the reens, b) at point of discharge to Monks Ditch and c) on the downstream sensitive receptor of the Gwent Levels reducing the mobilisation of suspended solids and particulates to the Gwent Levels. As part of the agreement with NRW the old discharge to the industrial system in the south will continue in operation until plots are remediated and reclamation completed. A phased switch over to the new scheme will be undertaken as each phase is completed and new reens constructed. This allows a period of monitoring and water quality assessment prior to switching to pumping to Monks Ditch. During the long term operation of the drainage system the vegetated nature of the reens and the extended residence time, especially during storm events, provides a valuable element of the treatment train. Although the modelled impacts from residual contaminants are low the rejuvenated drainage system provides additional mitigation to manage minor quality variables, for example, by improving downstream turbidity by reducing the mobilisation of suspended solids and particulates to the Gwent Levels.

Biodiversity Improvements include: n the footprint of the surface water drainage infrastructure has increased to allow for the additional storm storage requirement. An additional 20ha of blueways and greenways will have been created. n the size and form of the network varies and caters for a variety of managed planting schemes and natural rejuvenation. n the form of these areas will naturally discourage public access allowing a wide range of natural fauna and flora to regenerate along approximately 7km of interlinked blueways and greenways. n consideration has been given to retaining water on the site to act as a reservoir to provide water to the Gwent Levels in periods of prolonged drought important for the ecological management of the SSSI in future.

Works programme Statistics for the implementation of the drainage infrastructure include: n The opening up of 4350m of culverted waterways

n Removal of 43,500m3 of concrete

structures along the length of the historic industrial waterways n Creation of circa 7,500m of new waterway and the creation of circa 250,000m2 of green corridors n Upgrade and landscaping of 1000m of Monks Ditch n Modelling of 3700m of external waterway and the upgrade of control features along Monks Ditch. Practicality dictates that sections of reens are being created as site reclamation and development proceeds. The full implementation of the scheme is anticipated by 2020.

Conclusion - long term benefits and multifunctionality The design of the surface water drainage at Glan Llyn demonstrates an innovative response to sustainable urban drainage which considers a unique set of constraints. The flat site topography, a high level discharge to Monks Ditch and flood and water quality issues in the Gwent Levels have necessitated the consideration of the long term impacts of climate change and a need to manage conditions way beyond the site boundaries. This has been achieved by the innovative use of site specific flow modelling using real time data which demonstrates best practice. The design has forced a reconsideration of the purpose and functionality of the drainage system. This has allowed improvements in visual amenity and a landform which will encourage biodiversity. In the future the surface water infrastructure will be managed as a valuable asset by the Glan Llyn Management Company. This would provide a targeted revenue stream for the maintenance of the infrastructure and landscaped areas. Overall the drainage network is as an integral part of the character of the site providing a high quality urban landscape with benefits to downstream ecology and on-site bio-diversity.

Judgesâ&#x20AC;&#x2122; Quote: â&#x20AC;&#x153;This project showed how historical drainage systems can be adapted for 21st century purposes. By opening up parts of the previous culverted system, there will be more public open space and biodiversity has been improved. Thanks to this work, the site is a natural and desirable asset that will be attractive to developers and residents..â&#x20AC;?


29 | Brownfield Briefing Awards 2017

Best biodiversity enhancement (including SuDS)

JOINT WINNER:

River Ewelme, former engine manufacturing works, Dursley, Gloucestershire

ORGANISATIONS

Rodgers Leask Environmental Ltd and St. Modwen The Littlecombe development is a regionally important brownfield regeneration project led by St. Modwen Developments Ltd, located near Dursley in Gloucestershire at the edge of the Cotswolds. It occupies the site of the former Lister-Petter works and comprises 37ha of brownfield land to the north of the town. A key part of the project was the restoration of the River Ewelme, which has been culverted for more than 100 years. St. Modwen identified the environmental benefits of reinstating the river channel at an early masterplanning stage and focused on ensuring designs would maximise the long-term biodiversity benefits of the site and the Class A salmonid river. RA Lister and Company was founded in 1867 in the valley of the River Ewelme, merging many years later with Petters Ltd to form the Lister-Petter Company in 1986. Initially producing farming equipment, the engineering works manufactured diesel and petrol engines throughout the 20th century. The works housed its own foundry from the 1930s, and by the mid-1970s the casting division was producing 19,200t of engine parts per year. At its peak, Lister-Petter employed 5,000 people, the population of Dursley today being approximately 6,000. The vision for Littlecombe is to transform the former engineering works into a sustainable development, delivering high-quality residential properties with employment opportunities. The final development will provide 600 homes and a community hospital, as well as a 15ha business park. Following purchase of the site in 2002, St. Modwen entered a development agreement with the South West Development Agency and subsequently Stroud District Council to undertake a complex reclamation and remediation programme to transform the derelict factory into a new environmentally focused community. Rodgers Leask Environmental Ltd was the lead consulting engineer for the project and was involved in the enabling works,

reclamation, remediation, ecological enhancement and infrastructure engineering.

The River Ewelme The Lister-Petter works was constructed in the valley of the River Ewelme, which flows north where it becomes the River Cam on-site, dissecting the development in two. The River Ewelme was first culverted beneath the Lister-Petter works in 1902 to enable the expansion of factory buildings. The River Ewelme rises above the village of Uley on the Cotswold escarpment in Gloucestershire before flowing through Dursley and the Littlecombe Development. The River Cam then flows through the villages of Cam and Cambridge, where it joins the Gloucester and Sharpness Canal as a feeder to the waterway, which opened in 1827. Prior to this, the River Cam flowed into the River Severn at Frampton-on-Severn. Historically, the culvert extended more than 750m across the works, several metres below ground in a masonry arched channel, which had deteriorated and was in poor condition when St. Modwen was selected as the development partner for the site. The poor condition of the culvert had led to significant hydrocarbon contamination in the river. The regeneration of the Lister-Petter works is complex. In parallel to remediation of foundry sands (containing hydrocarbons and leachable metals), significant cut and fill works are required to deliver a developable plateau, resulting in the distribution of material across the valley floor. The excavation and relocation of the River Ewelme was integral to the masterplan to enhance biodiversity and local ecosystems as well as creating excellent visual amenity to the future residents of Littlecombe.

Ecological assessment The negative impacts of culverted watercourses on flood risk, ecology, and amenities have been widely acknowledged. The Environment Agency actively discourages culverting, particularly where

this completely encloses a watercourse. Opening up the culverted section of the River Ewelme could help create a diverse range of aquatic and bankside habitats and a natural resource of value to the entire Dursley district. Extended culverted sections of a river dramatically harm its environmental status and health by introducing problems such as: reducing ecological value within concrete or brick channels and with reduced light; inhibiting groundwater recharge; increasing downstream flood risk flows due to shortened response times and reduced flood retention in artificial channels compared with natural watercourses; adverse effects on environmental features and wildlife habitat including disruption of the linear habitat of a watercourse, stopping species from spreading naturally; and increasing upstream flood risk due to blockages of culverts or screens by water borne debris and/or constricted flood flows in the culvert itself. Consultation was undertaken throughout the design process with the EA, local authority, Hydroland (flood risk expert), and independent hydrologists and ecologists to maximise the long-term benefits of the new open sections of the Ewelme. Several opportunities were highlighted to re-profile the river in such a way as to create more natural and varied riparian habitats including: long pooled areas where the river bed is sunk up to 500mm below the rest of the river bed; point bars created out of washed gravel and shingle to form riffles; coir roll protection to reduce erosion and promote vegetation growth; and turns and meanders to create swirls and eddies. Ecological assessments highlight the fauna likely to benefit from de-culverting the River Ewelme includes bats (Noctule and Common Pipistrelle), newts (Palmate) and water voles (recorded downstream of the culvert). Up to 23 species of bird were also identified as potentially benefiting from the restoration of the river, including the song thrush, which is on the RSPB red list,


Best biodiversity enhancement (including SuDS)

along with the green woodpecker, dunnock, and mistle thrush, on the RSPB Amber list. The importance of the Ewelme restoration is clearly evident from the potential environmental benefits to the local fauna. The River Ewelme is classified as an upland river and should therefore have fast running water over a bed of rock and cobbles. The restored river channel will support sparse vegetation (such as mosses and liverworts), insects (such as stoneflies, mayflies, and caddisflies) and fish (including salmon, brown trout, and eels). Otters are known to live downstream on sections of the River Cam, and consulting ecologists have stated that opening up the river channel greatly increases the chances for the population to spread. Ecologically, “daylighting” the River Ewelme could dramatically increase the biodiversity of the watercourse. A continuous bankside was designed to allow the spread of native flora and fauna, encouraging the natural evolution of a continuous ribbon of rich and diverse habitat. The project has further improved the River Cam with respect to the passage of fish, tying in with recent installation of fish passes on the river near Cambridge.

Legislation and channel design Under the Water Framework Directive (WFD), culverted watercourses are termed Heavily Modified Water Bodies (HMWB) because they have been significantly altered by human activity and substantially changed in character. The WFD requires that Environmental Objectives are set for all surface and ground waters in England and Wales to enable them to achieve Good Status (or Good Ecological Potential for Heavily Modified and Artificial Water Bodies) by a defined date. In terms of the River Ewelme Channel Design, Rodgers Leask prepared designs for the River Ewelme Diversion Plan throughout 2015 and 2016. The channel design criteria agreed with the EA and other stakeholders were to: promote an open channel for the greatest distance on site physically possible; convey the modelled 1:100-year flood flow, including an allowance for climate change without any “out of bank” flooding; and allow a flat 8m easement from the top of bank of the new channel for maintenance access and for flood protection. An innovative ticked shaped channel was also agreed with an asymmetric profile. Side slopes were designed with a variety of gradients ranging from 1:2 to 1:5. Any of the grades steeper than 1:3 were maintained

Brownfield Briefing Awards 2017 | 30

above the flood level for slope stability reasons, and new structures such as bridges, culverts, and outfall headwalls were to be kept to a minimum along the length of the new watercourse. The Principal Contractor (Hawk Group) was engaged to form the diversion route of the River Ewelme. This task involved several strands. A channel of compacted clay with a minimum thickness of 750mm was to be formed from the watercourse bed to the crest of the batters, to the line and level agreed with the EA. Site-won natural clays belonging to the Dyrham Formation were tested for compliance relating to permeability and chemical composition. Clay placed in the 750mm layer was compacted to achieve a maximum permeability of 1x10-8m/s. Chemically and geotechnically verified material was placed in the floor of the channel and compacted in 250mm layers, and coir and erosion control matting was then placed on the finished works to reduce the potential for erosion of the placed clay. The design is intended to replicate a naturally formed riverbank ecosystem which, prior to the river being culverted in 1902, ran the entire length of the River Cam Valley. Works to form the channel for the new watercourse were undertaken in two stages. The first stage was completed in 2009, with the second phase now nearing completion. The river diversion was completed in parallel to reclamation works on the adjacent housing plots.

Development advantages Notwithstanding the overwhelming advantages that daylighting the River Ewelme has created ecologically by providing a valuable wetland/aquatic habitat, aiding fish passage and significantly adding to the visual amenity of the area, the naturalised river has many other advantages for Littlecombe. It has enhanced pedestrian and cycle routes, giving residents an accessible area of countryside in the town. Swirls and riffles in the river produce noise that drown out urban sounds and provide an atmosphere of quiet and calm. The wider site complements urban initiatives and boosts house prices. Increased watercourse capacity and lag times reduce flood risk downstream. Furthermore, a dilapidated structure has been removed, cost savings were achieved during construction and maintenance using natural bioengineering techniques, and the work gives Littlecombe a sense of identity, differentiating itself from other developments.

Community acceptance and project legacy The local authority and EA were consulted by Hydroland and Rodgers Leask from the outset of the design process. The EA was able to highlight its observations and requirements regarding the design of the reinstated River Ewelme and subsequently enable all parties to agree on a set of design principles for the creation of the new river channel. It was also agreed with the local authority and EA that ongoing quarterly sampling and visual inspection of the water quality in the River Ewelme should take place. This is anticipated to continue post-completion, allowing an assessment of how water quality changes over time. The impacts on ecology from the works will also be assessed post-completion. The long-term benefits from reinstating the river channel will be significant to both ecology and the local environment. While meeting the requirements of the Littlecombe development in terms of the channel’s location and accommodation of a 1:100 year storm, St. Modwen was keen to ensure that the river channel was designed carefully to maximise ecological benefits. The channel has recreated a natural river habitat and, by including design specifications such as meanders, deepened pools, obstructions and shallows to produce eddies, riffles, and swirls, it will match that of an upland river. Hard engineering has been avoided to allow the use of subtle bioengineering techniques to reduce erosion, while encouraging biodiversity and improving the visual impact. The project’s success has been reliant on engagement with the EA, the local authority, flood risk experts, brownfield experts, hydrologists, and ecologists. In years to come, the channel will be a ribbon of river and bankside habitat that will have been colonised naturally by local native flora and fauna, providing Littlecombe residents with an area of countryside in an urban environment while also promoting biodiversity.

Judges’ Quote: “We were impressed by the remediation and restoration work completed at the site of the former engine manufacturing works project in Dursley, especially given that complex liaison with several departments at the EA was required. This project was a job well done.”


31 | Brownfield Briefing Awards 2017

Best biodiversity enhancement (including SuDS)

JOINT WINNER:

Silverton Mill, Devon

ORGANISATIONS

John F Hunt Remediation Ltd, DS Smith, Ecologia The requirement for DS Smith to remediate the former Silverton Mill, and surrender the lease back to the National Trust, provided the ideal opportunity for this enhancement project. The mill site is situated within the National Trustâ&#x20AC;&#x2122;s Killerton Estate. The River Culm, which runs through the centre of the site, plays an important part of the regionâ&#x20AC;&#x2122;s flood defence. The river and surrounding area provide a valuable habitat for a variety of flora and fauna. The transformation of the large culverted section of the River Culm into a diverse and attractive river corridor provided improved flood defences. The range of river and wildlife habitats introduced as part of the project enrich biodiversity and will attract tourism. Success was a product of true collaboration between the National Trust (land owners), DS Smith (leaseholder and operator of the mill), John F Hunt Remediation (remediation contractor), Ecologia (remediation designers), and the Environment Agency. Several teams within the EA were involved in the project including flood defence, biodiversity, geomorphology, contaminated land, and fisheries. This collective expertise assisted in integrating hydrology, flood defence, ecology, geomorphology, and landscaping to enhance the area, and will benefit wildlife as an exemplar of green infrastructure and surface water management.

The site The former paper mill site had a heavy industrial legacy dating back to the 1800s. This legacy had resulted in a negative visual impact, an adverse impact on the local ecology, and significant petroleum hydrocarbon contamination. The contaminants were present within the gravels alongside and below the culverted watercourse. Prior to remediation, the facility spanned the culverted River Culm and a smaller covered culvert (the mill leat channel) also ran the length of the site. Ecological surveys undertaken prior to the commencement of the works identified maternity roosts for Daubentonâ&#x20AC;&#x2122;s bats within a small section of culvert and Brown

River Culm post remediation looking east; limestone rock guide banks showing in foreground Long-Eared bats within the mill structure itself. While sensitive species such as reptiles and aquatic animals were not identified in significant in numbers, care was required to avoid adverse impacts on all wildlife throughout the works. The River Culm drains a large area of the Blackdown Hills and is prone to spate flows that can introduce a sudden surge of energy into the system. The River Culm was susceptible to full bank discharge at the Silverton Mill location, with the buildings and the area immediately surrounding the mill prone to severe flooding. This was caused in most part by the presence of the historic culverted structures, which spanned a width of up to 20m and a length of 160m. The mill and historic buildings to the south of the mill lacked any flood defence measures.

The challenge The presence of an industrial legacy, ecology issues, and a river that is prone to significant spate flooding required careful consideration and a multi-disciplinary approach to achieve the planned outcomes. John F Hunt Remediation was contracted to demolish Silverton Mill and excavate and treat the contaminated ground beneath the existing culverts. A significant aspect of the

works was to reinstate the River Culm with enhanced environmental and biodiversity benefits, introduce a groundwater base flow alleviation system, install rock armour flow protection, and create new grassed embankments. Most of the ground adjacent to the river culvert comprised loose, granular material with little integral strength. Significant hydrocarbon contamination was present in these granular materials along the north bank of the river, and were not suitable to form the banks of the high velocity river. Works were required to restore the significant culverted river, along with the remediation of the associated contaminated ground. To facilitate the works, a temporary diversion of the River Culm was agreed as part of the strategy; works were undertaken using a Flood Defence Consent. The former mill leat (the smaller of the two culverts) was opened out and installed with a welded HDPE liner for this purpose. The timing of the river diversion was agreed with fisheries officers from the EA to avoid spawning periods.

The solution The design of the newly created river channel required the construction of an oversize, predominantly over-wide profile,


Best biodiversity enhancement (including SuDS)

allowing some degree of natural freedom for the river to find a stable regime. The sizing of the newly created channel was determined by the width of the natural undisturbed channel upstream and downstream of the work area, along with the estimation of open channel flow rates. Discussions with the EA and the National Trust promoted the construction of a flood defence embankment to protect lower ground and retained listed buildings on the downstream bank on the western edge (the former clock tower and adjacent culvert). The river base was constructed as close to natural width as possible, but with gentle sloping banks to create a significantly widened flood stage channel. The over widening of the channel at flood levels was designed to reduce velocities and hence erosion pressure; these were important considerations with respect to long-term integrity of the 600mm clay liner and prevention of river contamination while ensuring that the newly placed artificial upper “benthic” layer would not be prone to erosion. Material selection was vital to the longevity of the river design and included the use of British Waterways-approved blue lias clay, a 200mm thick layer formed of recycled aggregates generated from the demolition process, and carefully selected quarried limestone material ranging in size from cobbles to boulders weighing several tonnes. Allowance was made for the natural deposit of sediment over time. The finished surface was completed at a reduced level of 200mm relative to the existing river bed to allow for the deposition and build-up of upstream sediments. A diverse and wildlife-friendly seed mix was developed with input from the EA’s Biodiversity Officer and wetland restoration specialists Salix. A variety of native grasses, sedges, rushes, reeds, and herbs were used, with seed mixes matched to anticipated wetness conditions on the banks of the channel.

Biodiversity enhancement The ambition of the partners to reinstate the site to pre-industrial heritage and provide enhanced biodiversity was realised through several design iterations and a series of stakeholder meetings to agree the final solution. It was important to ensure that measures were installed to permit the safe undertaking of the works, both for our team and the local wildlife. Early stages of the project involved fish relocation and innovative ecology mitigation measures.

Brownfield Briefing Awards 2017 | 32

The river reconstruction design was developed to include retention of a 40-metre section of the existing culvert adjacent to the clock tower. This was retained and enhanced to provide a suitable roosting habitat for the Daubenton’s bat. A bat curtain was installed to prevent the migration of bats into the river culvert during breeding season. Temporarily diverting the river was considered the most suitable solution to facilitate the remediation works. Following extensive consultation with the statutory authorities in respect of flood defence, geomorphology, biodiversity, groundwater, and contaminated land, the team designed and constructed a temporary HDPE lined river diversion channel. The temporary river diversion was formed from the smaller “river leat mill” channel. This allowed remediation of the ground around the main culvert to be completed without undue risk. The team liaised closely with the Environment Agency to monitor the River Culm and predict high flow conditions that might cause damage to the works and temporary channel. Petroleum hydrocarbon-impacted soils were excavated from the areas adjacent to the former culvert structures. Work was carried out under a Materials Management Plan (CL:AIRE Definition of Waste: Development Industry Code of Practice). Once the remediation works were complete, the former culvert was removed and the new naturalised river channel created. This included a groundwater base flow alleviation system, rock armour flow protection, and restoration of “natural” embankments. Rather than relying on man-made products such as the HDPE liner for the completed river installation, impermeable clay and limestone were sourced from local quarries. The impermeable clay also formed part of the remedial design, which was used to mitigate the potential migration of residual low level hydrocarbon contamination located at a depth below the new river formation. Habitats were maintained, restored, or diversified to increase the range of flora and fauna indigenous to the area. In consultation with the EA stakeholders and the local community, underrepresented or under threat animal, amphibian, and bird species were identified and suitable habitats were provided to strengthen numbers as appropriate. This included: installing new bat boxes in strategic locations, and retaining and enhancing a section of the culvert for Daubenton’s bat roosting; assessing the needs for movement corridors using

interconnected planting, water bodies and landscape features; assessing the flow and alignment of the relocated river to ensure it would be self-cleansing; building habitats to enhance protected and priority species; providing suitable access to allow local people to view the wildlife. The area immediately surrounding the Silverton Mill was prone to severe flooding caused by the 160m-long culvert and the lack of any suitable flood alleviation measures. Using a combination of historic analysis and the EA’s flood data, the team ensured that adequate water storage was built into the new river and the adjacent floodplain, thereby reducing the risk of flooding for adjacent communities and benefitting local wildlife.

Transformation into a new diverse habitat The former Silverton Mill site has now been cleared of built structures, contaminated ground remediated, and the river reinstated to promote biodiversity. The sustainable and environmentally sensitive design achieved by an iterative process meets the aims of the National Trust and its members, as well as the EA, while being appealing to the public. The solution to restore and enhance the River Culm corridor has reversed the loss of biodiversity, indeed making it possible for species to grow in numbers and increase in range. It has also provided a means of managing surface water as a contribution to the regions flood defences. The newly formed river banks were completed in July 2016 and the upper banks were completed in January 2017. The ecological system is therefore at a very early stage of establishment. However, as of June 2017, only six months after completion of seeding, perch, pike, kingfisher, green sandpiper, dippers, grey wagtail, goosanders, geese, swallows, swans, and dragonfly were seen in the restored area. The scheme has received positive feedback from the EA, who praised the “partnership approach to the project” and the “securing of a natural open channel feature”.

Judges’ Quote: “Regarding the Silverton Mill project, the judges said the natural, highly vegetated river restoration brings a lot of habitat improvements as well as being a local benefit in terms of public open space and flood alleviation.”


33 | Brownfield Briefing Awards 2017

Best Young Brownfield Professional

WINNER:

Sarah Poulton

ORGANISATION

WSP Remediation Ltd Sarah is an environmental hydrogeologist who has worked as a senior remediation consultant since joining WSP in 2013. She has five yearsâ&#x20AC;&#x2122; experience in the field of remediation engineering, working on a variety of contaminated land and groundwater projects across the UK. She has worked on projects from inception to completion. Her key responsibilities include extensive data analysis, interpretation and visualisation, designing and undertaking site investigation work, providing on-site technical support during groundwater and soil remediation projects, development and progression of the WSP digital platform, mentoring graduates, production of detailed quantitative risk assessments, regular liaison with clients and regulatory authorities, technical reviews of third party environmental reports and the compilation of technical reports, permits, risk assessments, and method statements.

Career history Sarahâ&#x20AC;&#x2122;s career within the brownfield industry began as an assistant environment engineer while undertaking a six-month placement at Vertase FLI as part of her MSc. During this time, she gained experience on-site and in the office, working on a variety of brownfield sites across the UK. She quickly gained confidence from the development of the Port Talbot Peripheral Distributor road, where the design and success of the bench-scale trials she completed led to the complete reuse of contaminated material on site, eliminating the requirement for off-site disposal and providing considerable cost savings. In 2013, Sarah joined WSP as a remediation consultant and was exposed to a wide variety of brownfield sites and remedial techniques. She was one of the main consultants working on the Esso Framework, progressing to Site Mature status. This enabled her to supervise and manage a wide range of site tasks while also maintaining a high level of health and safety in line with client safety expectations. She played a key role in several other projects before becoming largely officebased to manage a portfolio of petrol filling station sites. Her involvement in this area over the past two years has strengthened

Sarah Poulton (middle) with presenter Juliet Mann and Frank Evans, National Grid her skillset, including contaminant modelling and mapping, controlled waters risk assessment, data management and assessment, digital development, report writing, training, and client and regulatory liaison. She is now an integral member of the digital development team, working to develop, adapt, and roll out digital systems, alongside training colleagues in the use and management of the digital infrastructure. Sarah thoroughly enjoys her role within the brownfield industry and believes that the skills and knowledge she has developed throughout her career will help immensely as she continues on her career path. Sarah has played a key role in many projects. These include:

Port Talbot Peripheral Distributor Road, Port Talbot (2013) Sarah was the principal engineer responsible for both the design and completion of bench-scale trials and the execution of site-scale remediation for the stabilisation and solidification of naphthalene contaminated soils at the Port Talbot steelworks, as part of the Peripheral Distributor Road scheme. Sarah completed extensive laboratory trials, design, and management. This enabled all contaminated site-won materials to be treated as part of the works, removing the requirement for off-site disposal and

saving the client a lot of money. She designed and maintained a comprehensive materials treatment, placement, and validation strategy that accurately tracked all materials from pre-treatment through to appropriate validation. She was the primary point of contact for both client and regulatory liaison, and also took extra measures to monitor off-site residential locations and ensure local residents were kept informed throughout the works to minimise nuisance. The project was successful at the Brownfield Briefing Awards in 2013, winning the Best Conceptual Design award, and was highly commended in the Best Re-Use of Material category.

Felnex Trading Estate, Hackbridge (2014-2015) Sarah was one of the engineers responsible for delivering the remediation of a 15ha former cable manufacturing facility in Croydon, south London. During her nine-month site involvement, she managed and completed several tasks, including daily environmental monitoring, subcontractor management, liaison with adjacent neighbours, site surveying using a hand-held GPS system, and planning and overseeing the excavation and treatment of contaminated material. She was the principal engineer responsible for the detailed management


Best Young Brownfield Professional

of materials across the site and developed a comprehensive materials tracking system to ensure the location and treatment status of excavated materials were tracked at all times. Through the combination of on-site surveying and data modelling tools such as GIS, she was able to provide accurate records of the volumes of materials excavated, treated, reinstated, and disposed of off-site. This was made particularly difficult due to the split of the site into four areas based on end land use and the resultant calculation of three different specific assessment criteria; as such, it was vital to maintain up-to-date accurate records on the stages on treatment and to confirm the nature and volume of material that was suitable for reinstatement in different areas of the site. The system employed ensured maximum re-use of materials across the site, which resulted in cost savings for the client.

South East PFS Portfolio (NFA) Package (2015 - present) For the past two years, Sarah has been an integral part of the project management of a remediation portfolio comprising 23 petrol filling station sites across the south of England. At the outset, the project required the extraction and formatting of historic data from approximately 300 historic reports, and the construction of individual, bespoke databases. Sarah manages the technical delivery team. Not only does she manage and maintain the data for each site - which comprises multiple groundwater monitoring events, microbial data, intrusive investigation data, and hydrogeological assessment data - she also looks after the day-to-day running of the project both in the office and on-site. To date, she has written more than 80 factual and interpretive reports, including outline conceptual models, detailed remediation action plans, monitoring well installation reports, remediation performance reports, detailed quantitative risk assessments, and site closure reports - the issuing of which has involved considerable regulatory and client liaison. She has mentored many graduate and consultant level colleagues during the project, something which she is highly passionate about, thoroughly enjoys, and plans to continue. Throughout the project, Sarah has excelled in her understanding and knowledge of the company’s digital systems and the skills she has gained have aided her development.

Chilton Trinity Brickworks, Redrow Homes Ltd Sarah undertook both site- and officebased work on a Phase I and Phase II site

Brownfield Briefing Awards 2017 | 34

Ross Pollock, practice leader at WSP Remediation, said: “Since joining WSP in 2013, Sarah has become a valued member of our Remediation team. She has consistently demonstrated an ability to innovate and seek out better ways to complete project work, developing methods that have been adopted across our wider contaminated land business. “However, it is Sarah’s enthusiasm for her work, caring nature, and energy that make her stand out from her peers; using these qualities, she has become a very effective mentor for our graduate staff (and less technically savvy senior staff), developed excellent client relationships, and helped build a positive team spirit among her colleagues. Sarah’s significant project contributions have been numerous - consistently stepping up to take on the responsibility for delivering projects for our clients in the UK and across Europe. “Our high levels of trust in Sarah’s abilities have led to her current role: leading the technical delivery of a complex £2.5m project where we are managing legacy issues on a large portfolio of active filling station sites. In typical style, Sarah has taken this highly demanding project in her stride and has developed new methods of organising significant quantities of site information into bespoke, comprehensive databases, investigation at a former brickworks that was impacted by hydrocarbon. She enabled the redevelopment of the site for residential end-use. She undertook site investigation works around occupied residential dwellings. This included the supervision of drilling activities, soil logging and sampling, site characterisation, and groundwater and gas monitoring. She was subsequently involved in the analysis and modelling of data to inform the Detailed Quantitative Risk Assessment and Remediation Strategy, following which she was involved in site remediation works.

Patos Marinza Oil Field, Bankers Petroleum Albania Limited Sarah has been the main consultant working on behalf of Bankers Petroleum Albania Limited (BPAL) to complete Annual Groundwater Monitoring Reports for the Patos Marinza Oilfield in Albania since she joined WSP in December 2013. The production of each report requires an extensive review of groundwater chemical data collected by BPAL each quarter to provide a factual and interpretive assessment of groundwater and surface water quality on a yearly basis. Exported chemical data is imported into WSP’s geo-environmental database (gINT), allowing the robust

which have enabled the efficient construction of accurate site conceptual models to more clearly understand client liabilities. “Appreciating the need to tackle inherent inefficiencies in how we manage data, Sarah has also played a pivotal role in the development and use of bespoke digital tools to support the collection, management, and presentation of site data in formats that can be readily understood by clients, regulators, and fellow professionals. “As a digital Expert, Sarah provides support for the wider business and training in the use of digital tools. Notably, this has been in the use of GIS and database software to positively support investment in the roll-out and use of field tablets. “Outside WSP Remediation, Sarah runs the Early Career Practitioner (ECP) sub-group of RemSoc, which aims to integrate and support young professionals in the industry. Sarah has been integral in running the group, actively increasing member numbers through raising awareness of the society. “Sarah chairs a core group of members who produce and circulate newsletters, and she presented the ECP group aims and way forward at the RemSoc annual conference and the Contaminated Land Exposition. She has also organised, and is currently hosting, a series of technical webinars presented by co-professionals within the industry.” interrogation and assessment of data. The mastertable, produced by gINT, is linked to Microsoft Excel to provide bespoke Excel data outputs and enable the production of summary statistics and charts. The data management process allows for an ongoing assessment of data trends across groundwater and surface water monitoring locations, and the identification and subsequent reporting of any significant trends. Throughout the course of her involvement, Sarah has produced additional factual reports, primarily relating to the impact of site development works on the quality and contaminant status of controlled water bodies. To date, this has included extensions to infrastructure, installation of additional monitoring wells, and the excavation of additional “ecological pits” for managing and storing waste materials. Judges’ Quote: “We were extremely impressed by Sarah Poulton’s work. We were struck by the overarching work she’s done, and the fact that she was thrown in at the deep end and came up trumps marked her out. She has everything pretty well in balance, which is a very hard thing to do.”


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Soil/Groundwater investigation

Toxicology/Risk Analysis

Waste Management Licensing / Legislation

Remediation Planning/Management

Remediation Design & Supervision

Property & Environmental Audits

Landscape Architecture/Planning

www.aecom.com

Hydrology & Hydrogeology

Richard.bewley@aecom.com

Geophysics/Remote Sensing

Website Website

Geology & Geotechnics

0161 2376011

Email Email

Environmental Impact Assessment

Richard Bewley, Technical Director, EHS & Remediation Services, UK & Ireland

Telephone Telephone

Chemical Expertise and/or Laboratory

International

Contact NameName Contact

CQA/Verification & Monitoring

AECOM Ltd

Region Region

Biological/Ecological Expertise

Company Name

Archaeological Studies

● core area of expertise ○ further area of expertise

Air & Noise Impact Studies

UK Remediation Consultants

A Fortune 500 firm, AECOM is the world’s largest remediation company with over 5000 Remediation staff world-wide and a gross annual revenue from remediation projects alone of over $1 billion. We design, build, finance and operate infrastructure assets for governments, businesses and organizations in more than 150 countries. CGl (Card Geotechnics Limited)

UK-Wide, International

Ian Marychurch, Managing Director

01483 310600

IanM@cgl-uk.com

cgl-uk.com

CGL is an independent specialist consultancy combining geoenvironmental and geotechnical expertise. CGL’s deep understanding of ground and contaminant behaviour allows the company to give cost effective advice on complex site conditions. CGL provides value engineered solutions that often turn marginally viable developments on difficult sites into profitable opportunities. CampbellReith

UK-wide

James Clay, Partner

01737784500

jamesclay@campbellreith. com

www.campbellreith. com

CampbellReith is an independent firm of consulting engineers providing structural, civil, environmental, geotechnical, highways and transportation services. With a reputation for producing imaginative and cost effective design solutions, we are recognised by our clients as a firm of innovative and pragmatic thinkers. Land Quality Management Ltd

UK-wide, Europe, International

Paul Nathanail, Managing Director

01157484080

paul@lqm.co.uk

www.lqm.co.uk

LQM’s expertise delivers confidence for regulators and savings for developers and clients. Whether it is detailed risk assessment or value engineering remediation schemes - we can help. Visit our website to see how our services and training can deliver benefits to you and YOUR clients. Rodgers Leask Ltd

UK - wide

Sean Leach, Director - Business Development

01332 28500

sean.leach@rodgersleask. co.uk

www.rodgersleask.com

Rodgers Leask delivers major civil engineering and building projects and takes pride in providing high quality, innovative solutions. Our highly qualified team of civil, structural and geo-environmental engineers achieve excellent service levels by drawing on years of experience in addressing the most complex technical issues. We have a hard-earned reputation for providing cost effective, practical, buildable solutions, whilst developing close working relationships with clients and fellow professionals. Skyhawk Global Ltd

International

Andrew East, Managing Director

07944739202

andrew.east@skyhawkglobal. wales

www.skyhawkglobal.net

Skyhawk Global provides a comprehensive consultancy service for bio remediation solutions for hydrocarbon contaminated land and waste water applications. We also supply a comprehensive Bioaugmentation product range and solutions that are largely bacteria and enzyme based for use in a spectrum of applications from waste water to aquiculture and agricultural. Waterman Infrastructure & Environment Ltd

UK-wide

Carl Slater, Technical Director

020 7928 7888

carl.slater@watermangroup. com

www.watermangroup. com

Delivers multidisciplinary engineering solutions to the property, construction and redevelopment sectors. Services include site investigations, risk assessment, cost effective remediation and contract management. Reporting to facilitate planning conditions discharge. Waste classification advice on excavated materials during development and contract negotiations. Our experience brings strategic advice to minimise risk and costs.

*The details in these tables are from responses to a recent online survey. If your company wants to be included in directoty listings in the next issue of Remediation Solutions, please email either petya@environment-analyst.com or sales@environment-analyst.com


griffd@dixonltd.co.uk

www.dixonltd.co.uk

UK-Wide

Steve Davies, Business Development Manager

07874 213535

steve.davies@grm-uk.com

www.grm-uk.com

Ground Direct Ltd

UK wide

Mike Wilyman, Director

mike.wilyman@ groundirect.co.uk

www.groundirect.co.uk

GVA

UK wide

Paul Nixon, Head of Environmental Services

0121 609 8226

paul.nixon@gva.co.uk

http://www.gva.co.uk/ environmental-services/

Idom Merebrook Ltd

International

Simon Edwards, Director

01773 829988

sedwards@merebrook. co.uk

www.merebook.co.uk

IKM Consulting Ltd

UK-wide

Liz Copland, Environmental Associate

01324 878822

liz@ikmconsulting.co.uk

www.ikmgeoenvironmental.co.uk

John Grimes Partnership Ltd

South West

Meloney Celliers, GeoEnvironmental Engineer

01752 690 533

post@johngrimes.co.uk

www.johngrimes.co.uk

Jomas Associates Ltd

UK-wide

Roni Savage, Technical Director

08432892187

rs@jomasassociates.com

www.jomasassociates. com

JRS Consultants Ltd.

North Scotland, UK-Wide.

Ian Sidebottom, Senior Consultants

07847828780

ian.sidebottom@ jrsconsultantsltd.co.uk

www.jrsconsultants.biz

LBH WEMBLEY ENGINEERING

UK

Seamus Lefroy-Brooks, Principal

01280 812310

seamus@LBHGEO.co.uk

LBHGEO.co.uk

Leap Environmental Ltd

UK wide

Helen Smith, Director

01306 646510

hs@leapenvironmental. com

leapenvironmental.com

LQM - Land Quality Management Ltd

UK; EU; International

Paul Nathanai,l Managing Director 0115 748 4080

paul@lqm.co.uk

www.lqm.co.uk

Lund Advisors Chengdu

China, with a focus on West China

Patrik Lund, Environmental Advisor

+86 28 8515 0986

pl@lund-advisors.com

www.lund-advisors.com

Market Cross UK Limited

International

Greg Wells Managing Consultant

01929 401040

greg@marketcross.org

www.marketcross.org

Matthews Scott

Uk-wide

Paul Ricketts, MD

Mayer Environmental Ltd

UK wide

Rebecca Beddard, Senior Environmental Consultant

Griff Dixon Associates Ltd

UK Wide

GRM Development Solutions

07494530494

○ ○

○ ○

○ ○

● ●

○ ○

● ●

● ○

Waste Management Licensing / Legislation

01636 636565

Les Rodger, Principal Geologist

Toxicology/Risk Analysis

Griffin Dixon, Chartered Environmental Surveyor

UK-wide

Soil/Groundwater investigation

www.greencatrenewables. co.uk

Green Cat Geotechnical

0161 232 7465 02082911354

Remediation Planning/Management

les@greencatrenewables. co.uk

Peter George, Managing Director

Remediation Design & Supervision

01506-416553

Emma Bates, Marketing Manager

England & Wales

Property & Environmental Audits

www.gosolve.co.uk

UK and Australia.

GO Contaminated Land Solutions Ltd

Landscape Architecture/Planning

www.ggs-uk.com

mail@gosolve.co.uk

GGS

+33160749090

Hydrology & Hydrogeology

emma.bates@ggs-uk.com

Jean-Jacques Péraudin, Sales Manager Environment

Geophysics/Remote Sensing

Worldwide

Geology & Geotechnics

GEOVARIANCES

Telephone Telephone

Environmental Impact Assessment

http://www.geovariances. com/en/

Contact Name Contact Name

CQA/Verification & Monitoring

Archaeological Studies

sales-env@geovariances. com

Region Region

Company Name

Chemical Expertise and/or Laboratory

Website Website

● core area of expertise ○ further area of expertise

Biological/Ecological Expertise

Email Email

Air & Noise Impact Studies

UK Remediation Consultants

Paulricketts73@hotmail. com 442088473637

rebecca.beddard@mayerenviro.com

www.mayer-enviro.com


Waste Management Licensing / Legislation

Toxicology/Risk Analysis

Soil/Groundwater investigation

www.mkenvironmental. co.uk

Remediation Planning/Management

info@mkenvironmental. co.uk

Remediation Design & Supervision

07527268345

Property & Environmental Audits

www.mjca.co.uk

Landscape Architecture/Planning

kevineaton@mjca.co.uk

Hydrology & Hydrogeology

01827717891

Geophysics/Remote Sensing

http://www. metconsultancygroup. com

Geology & Geotechnics

ami.cooper@ metconsultancygroup. com

Environmental Impact Assessment

www.mayer-enviro.com

CQA/Verification & Monitoring

rebecca.beddard@mayerenviro.com

Chemical Expertise and/or Laboratory

Website Website

Biological/Ecological Expertise

Email Email

Region Region

Contact ContactName Name

Mayer Environmental Ltd

UK-wide

Rebecca Beddard, Senior Environmental Consultant

Met Consultancy Group

UK-wide

Ami Cooper, Senior Engineer

MJCA Limited

UK-wide

Kevin Eaton, Technical Director

MK Environmental

Northern Ireland

Mark Kelly, Principal

NOrth West Environmental

Ireland

Davide Gallazzi, Environmental and Energy Consultant

Opus International (uk) Ltd

Uk wide and international

Paul Eastwood, DirectorEnvironment

01159601200

paul.eastwood@ opusinternational.co.uk

www.opusinternational. co.uk

Oracle Environmental Experts

UK-wide

Jon Burton, Managing Director

01684252858

jburton@oracleenvironmental.com

www.oracleenvironmental.com

Overwatch Geo

South East England, and internationally.

Dr R A Lockwood, Geophysicist

Peter Brett Associates LLP

UK-wide

Catherine Copping, Associate

01189500761

ccopping@peterbrett.com

www.peterbrett.com

PJA Engineering

Midlands and South

Becky Lowe, Associate Director

01215165184

becky.lowe@ pjaengineering.co.uk

https://www. pjaengineering.co.uk/

Provectus Remediation Ltd

UK-wide

Stephen Langford, Managing Director

info@provectusgroup.com

www.provectusgroup.com

QTS Environmental

UK-wide

Simon Rudd, Business Development Manager

simon.rudd@ qtsenvironmental.com

www.qtsenvironmental. com

Red Rock Geoscience, Ltd

UK Wide

Paula Warke Principal Consultant 01392460800

p.warke@redrockgeo. co.uk

www.redrockgeo.co.uk

Roberts Environmental Limited

UK wide

Andrew Cuthbert, Principal Consultant

andrew@ robertsenvironmental. co.uk

http://www. robertsenvironmental. co.uk/

RPS

International

Andy Clifton, Managing Director Environment & Infrastructure

01454 853000

cliftona@rpsgroup.com

www.rpsgroup.com/uk

RPS Consulting Services Ltd

International

Andy Clifton, Managing Director

01454 853000

cliftona@rpsgroup.com

www.rpsgroup.com/uk

RSK

International

Cathrine Matthews

cmatthews@rsk.co.uk

www.rsk.co.uk

SEnSe Associates LLP

London & SouthEast

Mike Summersgill, Managing Partner

senseass@btinternet.com

www.remtechuk.com

Southern Testing

UK wide

Dr Lawrence Mockett, Joint Managing Director

01342 333100

lmockett@ southerntesting.co.uk

www.southerntesting. co.uk

Southern Testing Laboratories Limited

South & Midlands

Julia Warren, Senior Environmental Scientist

01342 333100

jwarren@southerntesting. co.uk

www.southerntesting. co.uk/

Company Name

Telephone Telephone

Archaeological Studies

● core area of expertise ○ further area of expertise

Air & Noise Impact Studies

UK Remediation Consultants

+442088473637 0113 200 8900

00353 87 6159616

solutiions@ northwestenvironmental. ie ●

01924489259

01622820429

Overwatchgeo@yahoo. com

01245 505600

● ●

● ●


www.tfigroup.co.uk

The Land Trust

UK-wide

Mr Iain Taylor, Director of Business Development

01925 852005

iaintaylor@thelandtrust. org.uk

www.thelandtrust.org.uk

Townsend Associates

London, South East, South, Midlands.

Steve Townsend, MD

07815 769335

www.townsendassociates. steve@ townsendassociates.co.uk co.uk

Turnkey Regeneration Ltd

South

Dave Rutherford, Director

07540295282

dave.rutherford@ turnkeyregeneration.com

WDE Consulting Ltd

International

Simon Ware

01442825570

sware@wdeconsulting. co.uk

Wilson Associates (Consulting) Limited

UK-wide

David Wilson, Director

WISER Environment Ltd

UK-wide

Charles Thomas, Director

Wood (formerly Amec Foster Wheeler)

International

Matt Logan, Associate Director

WSP

International

Richard Clayton , Director

www.turnkeyregeneration. com

www.wilsonac.co.uk

charles@wisergroup.co.uk

http://www. wiserenvironment.co.uk/

020 3215 1700

matt.logan@woodplc.com

www.woodplc.com

+44 77 1398 5864

Richard.Clayton@wsp.com

www.wsp.com

01480462232

● ●

info@wilsonac.co.uk

01452 422843

Waste Management Licensing / Legislation

Ben.dewaal@tfigroup. co.uk

Toxicology/Risk Analysis

Ben de Waal, Director

Soil/Groundwater investigation

UK Wide

Remediation Planning/Management

The Fiscal Incentives Group Ltd

Remediation Design & Supervision

N/A

Property & Environmental Audits

sue.slaven@btinternet. com

Landscape Architecture/Planning

0740 360 6234

Hydrology & Hydrogeology

Sue Slaven, Contaminated Land Consultant

Geophysics/Remote Sensing

South East

Geology & Geotechnics

Sue Slaven

01214555090

Website Website

Environmental Impact Assessment

Email Email

Chemical Expertise and/or Laboratory

Telephone Telephone

CQA/Verification & Monitoring

Contact Name Contact Name

Biological/Ecological Expertise

Region Region

Company Name

Archaeological Studies

● core area of expertise ○ further area of expertise

Air & Noise Impact Studies

UK Remediation Consultants

● ○

● ○

● ●

● ●

*The details in these tables are from responses to a recent online survey. If your company wants to be included in directoty listings in the next issue of Remediation Solutions, please email either petya@environmentanalyst.com or sales@environment-analyst.com


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Landfill/Soil treatment centre

Phytoremediation (ex-situ)

Vitrification/Incineration (off-site)

Solidification/Immobilisation (exsitu)

○*

Stabilisation in/ex-situ (cover layers)

○*

Thermal Treatment Plant (ex-situ)

Magnetic/Chemical Separation

Soil Washing/Jet Washing

Hydrofracture/Injection

Bioreactors/Sludge Treatment

In-Ground Barriers/Mixing

www.aecom.com

Permeable Reactive Barriers

Richard.bewley@ aecom.com

Landfarming/Biopiling

0161 2376011

Electrolysis/ElectroRemediation

Richard Bewley, Technical Director, EHS & Remediation Services, UK & Ireland

Website Website

DVE/Bioslurping

International

EmailEmail

Soil Vapour Extraction

AECOM Ltd

Telephone Telephone

Pump & Treat

Contact NameName Contact

In-situ Heating/Steam Injection

Region Region

In-situ Chemical Addition/Reaction

Company Name

In-situ Air Sparging/Venting

○ technique available, using subcontractors or subcontracted equipment ●○ technique available, using either in-house or subcontracted equipment

In-situ Bioremediation/Injection

* EP issued ◊ EP application pending ● technique available, using in-house equipment

MNA (monitored natural attenuation)

UK Remediation Contractors

A Fortune 500 firm, AECOM is the world’s largest remediation company with over 5000 Remediation staff world-wide and a gross annual revenue from remediation projects alone of over $1 billion. We design, build, finance and operate infrastructure assets for governments, businesses and organisations in more than 150 countries. Celtic Technologies

UK-wide

Kathy Newall Business Development Manager

07985 836227

kathy,newall@ celtic-ltd.com

www.celtic-ltd.com

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Celtic-EnGlobe is one of the leading remediation and Brownfield Enabling Works contractors In the UK, with a proven track record of delivery after more than 20 years in the industry. Celtic-EnGlobe is part of Englobe Corp., a world leader in providing integrated environmental services which operates in the UK, France, The Middle East, USA and Canada. By partnering with us, you are able to rely on our extensive experience and delivery capability. GeoStream Uk Ltd

UK-wide

Chris Evans, Technical Director

01902 906205

chris.evans@ mcauliffegroup. co.uk

www.remediation. com

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GeoStream UK is the only single source provider of tried and tested remediation technologies in the UK, being the exclusive provider of Trap & Treat® (BOS 100® & BOS 200®) and the full range of injectable substrates supplied by Carus Remediation Technologies for the UK and Ireland. Hydrock Contracting Limited

Uk-wide

Christine Mardle, Technical Director

01454 619533

grahammun day@hydrock.com

www.hydrock.com

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Hydrock is a specialist land remediation company. Our in-house technical resources develop remediation schemes through site appraisal, design, pilot trials and regulatory agreement. They work alongside our sitebased teams and in-house plant resources providing safe and efficient site works delivered on budget and to programme. McAuliffe Civil Engineering Ltd

UK-wide

Lucy Martinez, Communications Manager

0161 928 7740

lucy@mcauliffe group.co.uk

www. mcauliffegroup. co.uk

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McAuliffe delivers solutions in brownfield site transformation at land acquisition and build-out stages. The business offers a full turnkey service, with core capabilities including soil and groundwater remediation, haulage and materials management, ground improvement and foundation solutions, and demolition services. Soil and Water Solutions Ltd.

UK-wide

Paul Garrett, Remediation Manager

02036678666

paul.garrett@ soilandwater solutions.com

www.soilandwater solutions.com

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S&WS Ltd is a licensed specialist environmental and enabling works contractor providing sustainable in-situ and ex-situ remediation, bulk excavation and disposal/ recycling using our own plant, on time and budget. Our in-house expertise enables delivery of bespoke brownfield solutions for treatment of contaminants including hydrocarbons, asbestos and Japanese Knotweed, nationwide. Sanctus Limited

UK-wide

Peter Cooke, Managing Director

01453 828222

pcooke@ sanctusltd.co.uk

www.sanctusltd. com

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Sanctus is a specialist remediation contractor offering solutions for all issues associated with Brownfield land development, including a wide range of in-situ and ex-situ soil and groundwater remediation techniques. Sanctus hold a bespoke Environmental Permit for the onsite treatment of hazardous waste and are also a licensed asbestos contractor.

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Skyhawk Global Ltd

International

Andrew East, Managing 07944739202 Director

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Landfill/Soil treatment centre

Phytoremediation (ex-situ)

Vitrification/Incineration (off-site)

Solidification/Immobilisation (exsitu)

Stabilisation in/ex-situ (cover layers)

Thermal Treatment Plant (ex-situ)

Bioreactors/Sludge Treatment

Landfarming/Biopiling

Magnetic/Chemical Separation

Soil Washing/Jet Washing

Hydrofracture/Injection

In-Ground Barriers/Mixing

Permeable Reactive Barriers

Electrolysis/ElectroRemediation

DVE/Bioslurping

www. skyhawkglobal.net

Soil Vapour Extraction

andrew.east@ skyhawkglobal. wales

Pump & Treat

Website Website

In-situ Heating/Steam Injection

Email Email

In-situ Chemical Addition/Reaction

Telephone Telephone

In-situ Air Sparging/Venting

Contact Name Name Contact

In-situ Bioremediation/Injection

Region Region

Company Name

○ technique available, using subcontractors or subcontracted equipment ●○ technique available, using either in-house or subcontracted equipment

MNA (monitored natural attenuation)

UK Remediation Contractors * EP issued ◊ EP application pending ● technique available, using in-house equipment

HydroEater is a Hydrocarbon Bioremediator which is unique to Skyhawk Global. It is part of our exclusive range of bioremediation and bioaugmentation products specially formulated to break down specific contaminants on a variety of substrates including soil and water. Our products have undergone vigorous testing by independent third parties. Soilfix Limited

North, Midlands, Wales & South

Steve Jackson, Director

07841 919525

steve@soilfix.co.uk

www.soilfix.co.uk

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Soilfix is an award-winning remediation solutions provider to the development, industrial, commercial and public sectors. Our mission is “to understand and manage risk in the ground”. Soilfix has developed an outstanding track record for delivering innovative remedial solutions for contaminated and brownfield sites. Ecologia

Ecologia

UK - wide and International

TM

experts on the ground

DEME Environmental Contractors UK Ltd

Paul Sheehan, Director

+44 (0)1795 471611

p.sheehan@ ecologiaenvironmental.com

www.ecologiaenvironmental. com

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Ecologia is a award winning multi-disciplinary, specialist contaminated land consultant/contractor that provides advice and undertakes site investigation and remediation projects across the UK and Internationally. We also have an established and excellent reputation for the construction and operation of in-situ UK and International

Jim McNeilly

07713121839

mcneilly.james@ deme-group.com

www.deme-group. com/dec

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DECis one of Europes leading environmental remediation contractors with more than 25 years worldwide experiencein the treatment of contaminated soil,sediment and groundwater using both in situ and ex situ technologies (on and off site). Projects undertaken range from small petrol station clean ups to large scale, complex, multidisciplinary remediation schemes.

Acorn Waste Management

UK Wide Waste Services & Aggregates

Mark Albery, Hazardous & Bulk Waste Manager

07436 280259

mark.albery@ acornwaste.co.uk

www.acornwaste.co.uk

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Augean PLC

UK-Wide Middlesbrough and Peterborough

Laura Hodgson, Key Account Manager

07718 706 851

laurahodgson@ augeanplc.com

www.augeanplc.com

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Coleman Remediation Services Ltd

UK-wide

01932 577290

info@colemanremediation.co.uk

www.colemanremediation.co.uk

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+44 (0) 7713121839

mcneilly.james@ deme-group.com

www.deme-group.com

0121 356 4360

info@dunton environmental. co.uk

www.dunton environmental.co.uk

07718 638814

philip.norville@ dynasafe.com

www.bactecuxo.com

UK - wide and International

Dunton Environmental

Tim Mckee, Business Development Manager

Dynasafe BACTEC Limited

National

Ecofficiency Ltd

Waste Management & Recycling

07506404074

simon.raven@ ecofficiency.co.uk

www.ecofficiency.co.uk

ELDC

ELDC AREA

01507613471

arshad.bhat@elindsey.gov.uk

LOUTH

Envirotreat Technologies Limited

UK wide

Enquiries@ envirotreat.com

Www.envirotreat.com

ERM (Environmental Resources Management)

International

07393750774

harriett.bill@erm. com

http://www.erm.com/

GeoRem International

South Africa, SubSaharan Africa

027117913490

theo@georem. co.za

www.georem.co.za

Geotech

International

01926338111

m.white@geotech. co.uk

www.geotechuk.com

Geovariances

Worldwide

+33(0)160749090

peraudin@ geovariances.com

www.geovariances. com/en/

I & H Brown Ltd

UK-wide

James Wood, Bid Manager

01738 637171

james.wood@ ihbrown.com

www.ihbrown.com

International Process Plant & Equipment

UK & Europe, US

Tom Nash, Director

tomn@ippe.com

www.ippe.com

Lucion Services

UK-Wide

charlottewright@ lucion.co.uk

www.lucionservices. com

David Slater, Technical Manager

01384 288876

01482240211

0191 4618999

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Landfill/Soil treatment centre

Phytoremediation (ex-situ)

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Vitrification/Incineration (off-site)

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Solidification/Immobilisation (exsitu)

Stabilisation in/ex-situ (cover layers)

Thermal Treatment Plant (ex-situ)

Bioreactors/Sludge Treatment

Landfarming/Biopiling

Magnetic/Chemical Separation

Soil Washing/Jet Washing

Deme Environmental Contractors (DEC UK Ltd)

Hydrofracture/Injection

www.cuddy-group.com

In-Ground Barriers/Mixing

meyrick.williams@ cuddy-group.com

Permeable Reactive Barriers

01792 321110

Electrolysis/ElectroRemediation

Cuddy Remediation UK Wide Ltd

DVE/Bioslurping

WebsiteWebsite

Soil Vapour Extraction

Email

Pump & Treat

Telephone Email

In-situ Heating/Steam Injection

Telephone Contact Name Contact Name

In-situ Chemical Addition/Reaction

Region Region

○ technique available, using subcontractors or subcontracted equipment ●○ technique available, using either in-house or subcontracted equipment

In-situ Air Sparging/Venting

Company Name

In-situ Bioremediation/Injection

* EP issued ◊ EP application pending ● technique available, using in-house equipment

MNA (monitored natural attenuation)

UK Remediation Contractors

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RAW Technology Ltd.

Across the UK and Ireland

03451668491

andy.kyle@rawgroup.com

www.raw-group.com

Remediate Limited

UK wide

01245206130

charlotte@ remediate-ltd. co.uk

Solids Control Services

Worldwide

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Storefield Group Ltd

UK-wide

The Land Trust

UK-Wide

The LK Group

Andrew Hardie, Project Supervisor

01224 249220

a.hardie@ solidscontrol services.com

www. solidscontrolservices. com

Jamie.Bartley@ Storefield.co.uk

www.storefield.co.uk

01925 852005

iaintaylor@ thelandtrust. org.uk

www.thelandtrust. org.uk

UK

0161 763 7200

h.bennett@ thelkgroup.com

www.thelkgroup.com

TRM Ltd

UK-wide and Ireland

0115 932 7222

a.mccluskey@ trm-ltd.com

www.trm-ltd.com

WSP

International

Richard Clayton, Director

+44 77 1398 5864

Richard.Clayton@ wsp.com

Vertase FLI

UK-wide

Jez Hardy, Business Development Manager

07775 678 491

jhardy@vertasefli. co.uk

07854162290

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Landfill/Soil treatment centre

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Phytoremediation (ex-situ)

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Vitrification/Incineration (off-site)

www.provectusgroup. com

Solidification/Immobilisation (exsitu)

info@ provectursgroup. com

Stabilisation in/ex-situ (cover layers)

01245505600

Stephen Langford, Managing Director

Thermal Treatment Plant (ex-situ)

UK-wide

Bioreactors/Sludge Treatment

Provectus Remediation Ltd

Landfarming/Biopiling

www.lucionservices. com/companies/mpcremediation/

Magnetic/Chemical Separation

Andrewwise@ mpcremediation. co.uk

Soil Washing/Jet Washing

0345 5040 303

WebsiteWebsite

Hydrofracture/Injection

International

Email

In-Ground Barriers/Mixing

MPC Remediation

Telephone Email

Permeable Reactive Barriers

www.mcauliffegroup. co.uk

Contact Contact Name NameTelephone

Electrolysis/ElectroRemediation

Soil Vapour Extraction

info@ mcauliffegroup. co.uk

Region Region

DVE/Bioslurping

Pump & Treat

0161 928 7740

Company Name

○ technique available, using subcontractors or subcontracted equipment ●○ technique available, using either in-house or subcontracted equipment

In-situ Air Sparging/Venting

In-situ Heating/Steam Injection

In-situ Chemical Addition/Reaction

In-situ Bioremediation/Injection

UK-wide

* EP issued ◊ EP application pending ● technique available, using in-house equipment

MNA (monitored natural attenuation)

McAuliffe Civil Engineering Ltd

UK Remediation Contractors

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*The details in these tables are from responses to a recent online survey. If your company wants to be included in listings in the next issue of Remediation Solutions, please email eitherpetya@environment-analyst. com or sales@environment-analyst.com


Remediation Solutions

Brownfield Briefing Talbot House, 11-15 Market Street, Shrewsbury, SY1 1LG United Kingdom Tel: 020 8969 1008 Fax: 020 8969 1334 Email: ian@environment-analyst.com www.brownfieldbriefing.com

Remediation Solutions - Issue 27  

Brownfield Briefing's Remediation Solutions guide

Remediation Solutions - Issue 27  

Brownfield Briefing's Remediation Solutions guide