Laurel Hill Hydrock GI Quote and Scope of Works

Over Court Barns Over Lane Almondsbury Bristol BS32 4DF United Kingdom

T +44 (0)1454 619533 F +44 (0)1454 614125 E bristol@hydrock.com

www.hydrock.com

Document ref: E14418.01 7th April 2016 Pegasus Group First Floor, South Wing Equinox North Great Park Road Almondsbury Bristol BS32 4QL For the attention of Will Collins Will.Collins@pegasuspg.co.uk

Dear Will Re: Proposal for Desk Study and Ground Investigation for Land at Laurel Hill, Cribbs Causeway, Bristol 1.0

Introduction Further to receipt of the supplied information, we are pleased to provide a Scope of Works and fee proposal for the desk study and ground investigation works at the above site. The site covers an area of approximately 2.5ha. and is located to the south east of Cribbs Causeway (A4018) at approximate NGR 357500E 180454N (postcode address of BS10 7TJ).

Hydrock has not had the opportunity to visit the site, however from the information supplied, it would appear that the site is currently open grassed field bounded to the south by the Henbury Trym stream, with the western end of the former Filton Airfield beyond. Residential properties of Catbrain Hill and New Charlton Way form the eastern and northern site boundaries respectively. A further open field lies to the west of the site and some commercial businesses are located to the north-west and west off The Laurels, again located off Cribbs Causeway. A footpath is understood to pass through the central section of the site in a general north-south alignment.

Whilst full details of the proposed development are not available at this stage, it is understood the development of the site will comprise the construction of residential dwellings with private garden, areas of public open space, attenuation pond and associated access infrastructure.

2.0

Ground Conditions Review of the geological map for the general site area (Sheet 264, Bristol) indicates the underlying geology to comprise the Mercia Mudstone Formation of Triassic age. It should be noted that the northernmost extents of the site may be underlain by the Blue Anchor Formation, again of Triassic age.

Hydrock Consultants Ltd Registered office: Over Court Barns, Over Lane, Almondsbury, Bristol BS32 4DF Registered in England & Wales no. 3118932 Birmingham Manchester

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The Mercia Mudstone is typically encountered as a red, less commonly green-grey mudstones with subordinate siltstones. The Blue Anchor Formation comprises pale green-grey mudstones and siltstones with thin arenaceous (sandy) lenses. Both of these lithologies typically weather to clays.

Reference to the BR 211 document entitled: ‘Radon - Guidance on Protective Measures for New Dwellings’, indicates that the site is an area where greater than 1% of properties are above the action level and radon protective measures may be required. A BGS Radon report is recommended to confirm this.

3.0

Suggested Scope of Investigation Works The works will be carried out in a phased approach. Phase 1 would be the desk study and Phase 2 will be the intrusive ground investigation. The scope of works for each phase is set out below: Phase 1 •

a review of topographical, geological and hydrogeological maps;

•

review of BGS radon report;

•

review of a specialist Unexploded Ordnance (UXO) report;

•

review of historical site maps to identify any former potentially contaminative site uses and an assessment of potential contaminants associated with those site uses;

•

an environmental database search to determine any former flooding, landfill, pollution incidents etc. at the site; and

•

a walk-over survey (normally carried out at the beginning of the Phase 2 fieldwork).

Phase 2 Subsequent to the Phase 1 desk study, an intrusive ground investigation will be undertaken. The Phase 2 Ground Investigation will comprise: •

the excavation of trial pits;

•

the undertaking of infiltration tests (if required);

•

geotechnical testing; and

•

contamination analyses of soil.

It is suggested to undertake 2 day of machine excavated trial pitting across the site. This will allow the excavation of 16 – 20 pits, to enable geotechnical and contamination samples to be taken.

Dynamic Cone Penetrometer (DCP) testing would also be undertaken at selected locations to inform preliminary pavement/roadway design.

The site is located in a high risk area for unexploded ordnance, mainly on account of being in proximity to the Filton Airfield which was a strategic target during WWII. Therefore in accordance with CIRIA C681, a preliminary risk assessment is deemed necessary for the site and would be required prior to the commencement of any ground investigation works.

Based on experience of sites in the vicinity of the subject site it is likely that the results of the risk assessment would recommend the presence of an Unexploded Ordnance (UXO) Engineer on site during any intrusive works to undertake appropriate surveys (magnetometer probing) within the

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progressed exploratory holes. The costs associated with this can be discussed upon appointment for the investigation works.

All site works would be supervised by a Hydrock Geo-environmental Consultant. Logging and sampling of trial pits would be undertaken in accordance with BS 5930:2015 ‘Code of practice for site investigations’ and BS 10175: 2013 ‘Investigation of potentially contaminated sites – Code of practice’.

Should you confirm that you wish for us to undertake the infiltration testing at this stage, the necessary equipment would be mobilized, along with a second man to monitor the tests, whilst the Engineer completes the trial pitting. The extra-over rate for the infiltration testing is presented as a separate item in the proposed fees below. We would undertake the infiltration testing during the planned days of site works, which should be sufficient to provide an indication of the suitability of the site for soakaway drainage. However, inherent variability of ground conditions means that further confirmatory testing at depths and locations of proposed soakaways is likely to be required at a later stage to allow detailed design.

Laboratory Testing Soils would be sampled as appropriate. Samples would be delivered to an accredited laboratory for subsequent geotechnical and contamination analyses on a ten day turnaround unless requested otherwise.

Based on the anticipated ground conditions and the method of investigation, we have allowed for a range of geotechnical tests including but not necessarily limited to: •

natural moisture content and Atterberg limits;

•

SD-1 suite for sulfate analyses; and

•

remoulded CBR.

Soil samples will be analysed for a range of contaminants based on the desk study and walk-over survey findings of past land uses. If groundwater is encountered it will be analysed for the following suite of determinands. In the absence of groundwater samples, soil samples will be subject to laboratory leaching and the eluate analysed for these determinands, in order to provide a generic risk assessment for the potential contamination of Controlled Waters.

Soil tests:•

Hydrock default suite of determinands for solids comprising: As, B (water soluble), Be, Cd, Cr (III), Cr(VI), Cu, Hg (inorganic), Ni, Pb, Se, V, Zn, cyanide (free), pH, asbestos screen, speciated polycyclic aromatic hydrocarbons (PAH, by GC-MS), total phenols and fraction of organic carbon;

•

Hydrock TPH Level 2 comprising carbon banding with aliphatic / aromatic split plus BTEX; and

•

Pesticide & Herbicide screens.

Water or soil leachability tests:-

•

E14418.001

Hydrock default suite of contaminants (waters, or standard leachate preparation from soil sample) comprising: Ag, Al, As, B, Ba, Ca, Cd, Co, Cr (III), Cr(VI), Cu, Fe, Hg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sn, Zn, V, cyanide (free & total), phenols (total), ammonium, bromate, chloride, fluoride, nitrate, nitrite, sulfate, PAH (speciated), pH, EC, DOC and hardness; and 3

•

Hydrock TPH Level 1 screening comprising carbon banding plus BTEX, if considered necessary.

It should be noted that the exact scope of testing could only be determined following the findings of the desk study and intrusive works. Additional testing where necessary would be discussed with the client and fees agreed prior to instructing the laboratory.

Reporting The report will present the factual results of the ground investigation including logs, photographs and test certificates, together with interpretation and a conceptual site model. Generic risk assessment of potential risks to the development will be presented according to the scope work. This will use currently accepted methodologies which are fully explained in the detailed appendices.

We will make recommendations with respect to foundations etc. and contaminated land, as appropriate, including recommendations for liaison with regulatory authorities or other third parties.

If unacceptable contamination is encountered, the report will include a provisional remedial strategy for dealing with it. An executive summary will also be included.

4.0

Price Schedule Our price for the proposed works is £7,520 and each element of works described above is provided separately for convenience.

A

Phase 1 Desk Study Information Gathering

£380

Including site walkover survey, historical maps, provision of a 3rd party environmental report & BGS radon report.

NB: this fee quotation is for a combined Phase 1 and Phase 2 report. If a standalone desk study report is required, an additional fee of £950 will apply.

B

Specialist UXO Desk Top Threat Assessment

£1,450

in accordance with CIRIA C681 C

D

E

Phase 2 Intrusive Ground Investigation

£2,070

•

Preparation of appropriate H&S Documentation;

£250

•

2 days engineer supervision;

£900

•

2 days operated JCB (or similar) hire; and

£845

•

Hire of DCP testing equipment.

£75

Laboratory testing

£1,520 £1,055

•

Contamination testing; and

•

Geotechnical testing.

£465

Assessment and reporting

£2,100

Combined Phase 1 & Phase 2 report (final version) TOTAL (excl VAT)

£7,520

Optional/Contingency items F

Infiltration Testing - Technician 1 day, standpipe licence, bowser hire etc, and permeability calculations and additional reporting requirements.

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£430

Additional laboratory testing (per sample) G

H

Hydrock standard suite of determinands

£80

Hydrock Level 2 hydrocarbon screens

£65

Asbestos quantification testing

£125

GPS Survey Kit

£450

Please note that our fees are inclusive of all disbursements but exclusive of VAT and assume that continuity of works can be maintained. Cancellation or postponement of site works within 3 working days of site commencement may result in abortive costs being incurred which will be passed on.

Hydrock Consultants Ltd Standard Terms and Conditions apply.

Hydrock shall not be responsible for any use of the report or its contents for any purpose other than that for which it was prepared and provided. Should the Client require to pass copies of the report to other parties for information, the whole of the report should be so copied, but no professional liability or warranty shall be extended to other parties by Hydrock in this connection without the explicit written agreement thereto by Hydrock. The report may be assigned by the Client by way of absolute legal agreement to a purchaser of all or part of the site to which the report refers (“The Site”) without the consent of Hydrock being required and such assignment shall be effective upon written notice thereof being given to Hydrock. No further assignments shall be permitted, unless expressly agreed in writing by Hydrock. In the event of the Client entering into a legal joint venture to develop The Site, the report can be regarded as having been issued by Hydrock jointly in favour of the Client and the joint venture partner, and in respect of the report Hydrock would owe the joint venture partner the same duty of care that Hydrock owed to the Client when Hydrock was instructed to prepare the report subject to all the matters contained or referred to in the report.

Fees exclude liaisons with the regulators and remediation and validation works (consultations, reporting and chemical testing). This would be addressed as part of any remediation for the site.

Reporting fees are based on the issue of a final report without revision. If a draft report is requested at the time of the enquiry, the fees include for one revision based on client (or other) feedback. All other revisions will be charged at our standard hourly rates with a minimum charge of £150.

One colour copy of the report plus a pdf copy on CD are included in the price. Extra paper copies can be provided at a rate of £50 per copy. Please ensure that you specify the number of extra copies required at the time of order. Subsequent to our original issue of reports, additional copies will be charged at £80 per paper copy and £25 per CD. Assumptions It is assumed the site is vacant and that we will have full access to all areas of the site. Beyond the use of cones and warning tape to demarcate working areas, we have not included any provision for fencing or hoarding. It is also assumed that site conditions are suitable for standard wheeled plant and four wheel drive vehicles. Due to the nature of the investigation there will be some inevitable disturbance. Should tracked plant and equipment be required additional costs would apply.

No allowance has been made for full, like-for-like reinstatement of trial pits. The trial pits will be backfilled with excavated arisings and compacted as far as practicable, using solely the excavator. It should be noted that trial pits may be left mounded to allow for subsequent settlement. If excessive spoil is produced, no allowance has been made for its disposal (unless stated otherwise in this letter).

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Excess spoil will therefore be left on site. It is assumed that there will be no restrictions in either moving plant around the site or in where trial holes can be excavated.

No reinstatement of any disturbance across the site is included. If this is not acceptable Hydrock will need to be advised prior to mobilising to site to ensure that appropriate alternative measures can be put in place.

We will retain soil samples for 4 weeks from submission of report and core samples for 12 weeks from submission of report after which they will be disposed of. Should you require longer-term storage, this can be arranged for an additional fee but must be requested with your order.

Our proposals for infiltration testing assume that a water supply is available close to site.

Please note that as our client, you have various duties under the CDM Regulations 2015. One of these is to notify us of live services on site. Please be aware that we will require a utilities services search prior to undertaking the works. Hydrock can arrange this for a budget figure of ÂŁ300 - ÂŁ400, dependant on third party costs. Please also be aware that it can take time for the information to be made available by the utilities company so it is strongly recommended that you procure this information at an early stage to avoid delay.

It is assumed that a suitably detailed site survey plan will be available in AutoCAD format such that we can plot our findings for the report. Our investigations will be located by taping from site features. However, should there be the requirement for exploratory hole locations to be surveyed, we would propose to record the locations using a GPS surveying kit, costs for which are presented in the table above. Please include this item within the appointment correspondence if required so this can be organised prior to the site works.

5.0

Time Schedule It is envisaged that the desk study could commence as soon as an official order for the works has been received. It is envisaged, due to current workload that the site works could begin within 3-4 weeks of receiving the official order. By this time the desk study searches would be available and the site investigation works could target any features identified. The report would be completed within 5 weeks of completing the site works.

We trust that the above meets your requirements, however if you have any queries or require any additional information, please don’t hesitate to contact the undersigned.

Yours sincerely, for Hydrock Consultants Ltd

Dan Coles Senior Geo-environmental Consultant dancoles@hydrock.com Encl:

Terms and Conditions.

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