CURRENTS VOLUME 18, NUMBER 1 WINTER 2016
RISING SEA LEVEL REQUIRES ENGINEERS TO THINK DIFFERENTLY John Englander, Rising Seas Group A very serious engineering challenge has arrived due to rising sea level. Most design specifications do not take into account a realistic range of sea level rise (SLR) over the planned or true lifetime of a project. This includes a vast range of work ranging from road elevations, to drainage contours, to bridge heights and tunnel entrances, water and wastewater infrastructure to nuclear power plants, refineries, ports, etc. Design life for projects is often 20 – 30 years. Adding the leadtime for project approval and construction can add another decade -- getting us to mid-century. By then, some scenarios for rising sea level now suggest that the average global sea level could be more than a foot higher. With land subsidence the amount of effective SLR could be far greater in some locations. Unusual storm patterns are also becoming more common, which can further
While design life and financing may only look to mid-century, the reality is that major buildings and infrastructure often are in use more than a century after construction. The latest sea level rise projections from the U.S. National Climate Assessment exceed six feet by the end of this century. That presents a new reality for the engineering community and a real challenge. The following are some facts that are often overlooked or misunderstood. Some could pose professional risks and even potential liability for engineers if not considered. 1. “Resiliency” to temporary localized flooding from storms and even extreme tides is confused with global higher sea levels that are almost certain to persist for more than a thousand years. Not only is SLR essentially permanent, as the base level, it will gradually keep
Last Ice Age
0 - 200 - 400
Adapted from Hansen & Sato
Sea Level (ft) T Anomaly (o C)
The graph of carbon dioxide, global average temperature, and sea level supports the case for long-term rising sea level and the need to plan differently. Over the most recent four ice age cycles it illustrates how the three lines move in rather close synchronization – though there can be a substantial “lag time “ of decades or longer as the ice sheets and glaciers adjust to long term changes in temperature. Global average temperature correlates with CO2, now at 400 ppm (parts per million). Global temperature has already warmed 0.85 degrees C, approximately 1.5 degrees F. The goal agreed at the recent COP21 Climate conference set an ambitious target to keep the warming to 2.0 degrees total. Ice melt and sea level have just started to rise and are accelerating. Sea level will continue to rise until a new equilibrium is reached. The geologic record suggests that the long term adjustment is approximately 65 feet of sea level change per degree C. While there are diverse estimates for how high sea level can rise this century, this view shows why many experts believe we need to begin engineering for sea level that will rise higher, far into the future.
increase flood risk beyond traditional patterns and design criteria.
Time (thousands of years before present) www.johnenglander.net
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INFORM, INSPIRE AND ENGAGE Let me begin by informing you about one of our international conferences held at the beginning of the New Year. Since 2006, ASCE-EWRI has been hosting international conferences in developing countries in an effort to encourage information exchange with developed countries as well as invest in technology transfer. Not only is the intent of these conferences to bring environmental and water resources professionals together to focus on the regional issues where the conference is located, but also to provide access to participants from a wide variety of backgrounds. Conference locations in the past have included New Delhi, India; Bangkok, Thailand; Chennai, India; Singapore; Marrakech, Morrocco; Izmir, Turkey; and Quito, Ecaudor. This year the 8th International Perspective on Water Resources and the Environment was held in Colombo, Sri Lanka on January 4-6, 2016. A good example that illustrates how this conference deals with regional issues is that there was a series of papers presented on various water treatment technologies to help deal with water purification and chronic kidney disease. President-elect Steve Starrett, Ph.D, P.E., D.WRE, F.EWRI, F.ASCE attended the conference as the official representative of the EWRI Governing Board. Steve had an awesome experience and I am including two photos from his trip. The first photo is of his meeting with students from the University of Peradeniya, Sri Lanka. The second photo
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is of him and EWRI member Curt Elmore on a swinging bridge while participating in one of the two technical tours. To inspire you I can highlight the efforts of A. Curt Elmore, Ph.D., P.E., M.EWRI, M.ASCE, an Assistant Professor at the Missouri University of Science & Technology. Curt has been instrumental with trying to connect ASCE-EWRI with Project Lead The Way or PLTW. PLTW is a leading provider of science, technology, engineering, and math (STEM) programs. Through world-class K-12 curriculum, high-quality teacher professional development, and outstanding partnerships, PLTW is helping students develop the skills needed to succeed in the global economy. To engage our members, I challenge you to become more involved with EWRI by joining one of our active committees that is working on producing or revising a publication. One publication currently being worked on involves revising a Manual of Practice with AWWA on Water Treatment Plant Design. Also, all members should register on EWRIâ€™s Collaborate site, which is a portal that allows you to communicate and collaborate directly with other water and environmental professionals. Just posted in January by EWRI Member Bao Chongtoua under Discussions was a call for volunteers to join the Sustainable Stormwater Committee. An earlier post by EWRI Member Jie Zhang was a call for volunteers to
Join the Task Committee on Computational Fluid Dynamics Applications in Water and Wastewater Treatment. Further information and contacts for these committees can be found using the link below: http://collaborate.ewrinstitute.org/home
David D. Dee, Jr., P.E., D.WRE, M.ASCE President, EWRI
One only has to look at the recent, unfortunate events in Flint, Michigan to be reminded that it should never be assumed that clean water will always be available, even in the United States. Water everywhere is threatened by pollutants from point and non-point sources, overuse, and now sea level rise and climate change. It takes sound science and engineering professionals working with community leaders to protect and preserve our water resources. In other words, it takes you! In this issue there is a broad variety of articles addressing local, regional, and international water issues. For example, John Englander provides an eye-opening article on sea level rise and its potential implications on infrastructure as well as the engineering profession. Steve Roy and co authors provide an innovative solution to extreme rain events from around the globe. Overall, I hope you find this Winter issue of Currents to provide a renewed awareness of how critical clean water is to society. To provide relevant content in future issues of Currents we need your articles. Please contact me at CDrummond@DrummondCarpenter.com or Veronique Nguyen at VNguyen@asce.org with any article suggestions or questions you may have regarding article submission. Either of us would be glad to help you through the process of getting published.
Chad Drummond, PE, D.WRE, BCEE
COAL AND COAL ASH: REAL AND POTENTIAL HAZARDS TO ENVIRONMENTAL HEALTH AND WATER QUALITY Rory Klinger, Department of Civil, Construction, and Environmental Engineering – San Diego State University Claudia K. Gunsch, Department of Civil and Environmental Engineering – Duke University Anastasia E.M. Chirnside, Entomology and Wildlife Ecology Department – University of Delaware
Figure B Figure A
Figure C Figure A – A 25-foot (7.6 m) wall of ash approximately 1 mile (1.6 km) from a retention pond in Kingston, Tennessee. Photo taken by Brian Stansberry - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=5583772 Figure B – Coal Ash Cleanup (Source: US Environmental Protection Agency) Figure C – Coal Ash Staging (Source: US Environmental Protection Agency) Figure D - Aerial photo of Duke Energy Coal Ash Spill (Source: US Environmental Protection Agency)
This article is the first of a four part exploration of the environmental health and water quality issues associated with coal combustion residuals prepared by the EWRI Environmental Health and Water Quality Committee. Part 2 will provide a detailed case study of the 2014 Dan River coal ash spill in North Carolina. Parts 3 and 4 will explore restoration activities, ethical considerations, and an end cap summary. The most often recognized threats posed by the use of coal in energy production are associated with air pollution and global climate change. While not being completely overlooked, the associated threats to water quality do tend to be forgotten when disastrous spills of hazardous combustion wastes fall out of the news cycle. This may be because the water quality risks are less intuitive and more discontinuous, or it may simply be a symptom of distaste for or ignorance of material processes and life cycles. Regardless of the reason, coal production and use has created and maintains significant threats to environmental health and water quality. The historically implicit acceptance
of these risks has been eroding for over a century, and the process has accelerated over the past 50 years. Research on global climate change has spurred a global assessment of coal as an energy resource. Recent major coal ash spills in the United States (US) have brought the water quality implications of coal ash management back into the spotlight. Furthermore, the global nature of the coal conversation has helped bring to light that while the water quality hazards of coal use are not global in scale, they are both local and regional problems that do occur globally. The top ten nations for total coal consumption as of 2012 were (from greatest to least): China, US, India, Russia, Germany, South Africa, Japan, Australia, Poland, and South Korea (source: US Energy Information Administration). Bottom ash is produced in all coal combustion, but the extent to which additional residuals (such as fly ash and gas scrubber slurries) are produced depends on air pollution control requirements and practices,
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which vary across regional and international borders. The manner in which these residuals are handled depends on their composition, predominant phase, and disposal requirements, which are all influenced by location dependent regulations, common practices, and markets for combustion products as resources. There are three major coal production areas within the US (Figure 1): the Appalachian Basin, the Interior Basin (Illinois, Indiana, Texas, Ohio), and the Western Basin (Wyoming, Montana, North Dakota, New Mexico, Utah, Arizona). The Appalachian Basin (AB), which includes the Appalachian coalfields and the Marcellus Shale, covers parts of Alabama, Georgia, Kentucky, Maryland, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia and West Virginia. The AB has supplied the US with coal since the early 1700’s. The region has consistently produced more coal than the other US coal basin regions, producing ~70% of the US coal until the 1970’s. Since that time, the production has decreased to about 43%. Annual production from the AB peaked at 476.8 million tons in 1997. By 2003, production decreased to 375.3
million tons. Most of the coal in the AB is obtained from relatively few counties found in three general locations or “sweet spots”: southwestern Pennsylvania; southern West Virginia, eastern Kentucky, and south western Virginia; and to a lesser extent, Alabama. In 2013, the approximately 642 coal-fired electric utilities in the US produced 39% of US electricity. This production generated approximately 113 million tons of coal combustion residuals (CCR) that include coal ash, boiler slag, and flue-gas desulfurization (FGD) solids (American Coal Ash Association). Coal ash consists of the leftover material after coal is burned, a mixture of fine powdery material released up a smoke stack (fly ash) and the heavier particles which remain at the bottom of the furnace (bottom ash). The composition of coal ash will vary depending on the source of coal used in a particular power plant. However, coal ash generally contains concentrated amounts of metals, naturally occurring radioactive materials (NORM), and other elements. The metals typically include: lead, mercury, aluminum, barium, manganese, cadmium, chromium, beryllium, cobalt, molybdenum, nickel, thallium, vanadium, and zinc. Common NORM elements (and their half lives) include: uranium 238 (238U t1/2= 4.5 x 109 years), thorium 232 (232Th t1/2= 1.3 x 109 years), radium 226 and 228 (226Ra t1/2= 1600 years; 228Ra t1/2= 5.8 years), lead 210 (210Pb t1/2= 22 years) and potassium 40 (40K t1/2= 1.3 x 109 years). Finally, common metalloid and non-metal elements include: arsenic, boron, antimony, selenium, and chlorine. Many of these elements have been classified as carcinogenic toxicants and/or as contaminants which affect the nervous system, causing cognitive deficits, developmental delays, and behavioral issues. Additional health impacts have been noted such as cardiovascular damage, lung and kidney disease, birth defects and impaired bone growth
in children, as well as gastrointestinal issues. At a local scale, acute and long term human and ecological risks stemming from exposure to coal ash materials vary based on the type of coal combusted at a particular power plant. This in turn dictates which metals and other substances are found in the coal ash. Local practices determine how the coal ash is treated, handled, and managed, including ultimate disposal following production. The US Environmental Protection Agency (EPA) final rule for “Disposal of Coal Combustion Residuals from Electric Utilities,” finalized in 2015, classified coal combustion residuals as a non-hazardous industrial solid waste under RCRA Subtitle-D. This provided important “national minimum criteria” regulatory guidance for coal ash handling, but it classifies coal ash in the same category as household garbage and established decision making power over planning, regulation, and implementation at the level of state and local governments, creating potential for conflicts of interest (http://www.epa. gov/coalash/coal-ash-rule; http://www3. epa.gov/region02/waste/dsummary.htm). The most common disposal methods for coal ash include storing dry coal ash in landfills and abandoned mines, disposing of coal ash mixed with water (slurry) in wet ash ponds (surface impoundments) and coal ash recycling. Dry ash landfill disposal and operations result in particles being blown away by the wind to neighboring communities or farther away. Risks are linked to inhalation exposure of windborne particles. Coal ash slurry is typically stored in large open impoundments. The Southeastern US contains about 40% of the nation’s coal ash impoundments. The approximately 450 impoundments across the region contain approximately 118 billion gallons (447 million cubic meters) of coal ash slurry. Many of these impoundments and landfills are unlined, leading to exposure as a result of contaminant leaching to groundwater or bioaccumulation in wildlife. The siting of these facilities in close proximity to surface water bodies also
drastically increases the risk of surface water contamination. Coal ash recycling options include encapsulation into solid structures such as bricks and bowling balls, use as structural fill for highway embankments or incorporation in wallboards. Some of these options appear to prevent the toxic materials from being rereleased at a later time while other applications may ultimately lead to the reintroduction of the toxic substances to the environment. Clearly, exposure risks vary greatly with the recycling approach and more research is needed to identify the best methods for coal ash disposal. Each disposal method comes with its own exposure pathways and risks. Most acute contamination events linked to coal ash, including the Clinch River, Virginia (1967), Bellews Lake, North Carolina (1976), Kingston, Tennessee (2007) and the Dan River, North Carolina (2014), resulted from the failure of surface impoundment structures. These failures led to thousands to millions of gallons (tens to thousands of cubic meters) of waste materials being discharged into local rivers and streams leading to massive fishkills. In 2009, the EPA rated the impoundment sites for hazard potential based on certain criteria such as structural integrity of the impoundment and developed a rating system expressed as less-than-low, low, significant, and high. The Southeast contains 21 of the nation’s 45 high hazard dams (EPA). The EPA estimated in that study that at least 535 US coal ash ponds are unlined, contributing significant additional risk of groundwater contamination. While recent actions, such as North Carolina in August 2014 approving legislation to cap or remove 30 ash dumps, are a step forward, the authors feel that the engineering community would benefit from more in depth discussion of coal ash issues. The next article in this series will explore the details of the 2014 Dan River coal ash spill in North Carolina. 5
INTEGRATED PLANNING FOR NITROGEN CONTROLS IN THE EXETER/SQUAMSCOTT WATERSHED â€“ NEW FLEXIBILITY BRINGS NEW OPPORTUNITIES Robert Roseen, Renee Bourdeau, Alison Watts, Paul E. Stacey, Theresa Walker, Cliff Sinnott, Ted Diers, Doug Thompson, Towns of Exeter, Stratham and Newfields, NH
The Squamscott River tidal marsh What is WISE? In 2015 the Water Integration for Squamscott-Exeter (WISE) project completed an Integrated Planning framework for three coastal communities including Exeter, Stratham, and Newfields, NH to provide recommendations for affordably managing permits for wastewater and stormwater. The project has received tentative approval to fulfill the Nitrogen Control Plan requirements for Exeter and overlapping MS4 requirements for both Stratham and Exeter pending some critical next steps. This was accomplished by making use of a new flexibility in EPA permitting called Integrated Planning. The project bridged legal and technical gaps through a collaborative process working with regulators and municipal staff to develop a product that stakeholders and regulators trust and support. The project quantified the economic and performance advantages of municipal collaboration and integration of water resource planning. Success of this new approach depends upon leadership by municipalities, trust in the process and outcome, technical capacity and innovation, and regulatory flexibility. The
process has included officials from the Towns of Stratham, Newfields, and Exeter working with a team from Geosyntec Consultants, the University of New Hampshire, Rockingham Planning Commission, Consensus Building Institute, and the Great Bay National Estuarine Research Reserve with funding was provided
The Squamscott River by aerial imagery
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by the NERRS Science Collaborative. What is Integrated Planning? Integrated Planning is a new EPA approach that allows a flexibility in permitting of wastewater and stormwater controls to plan for most cost effective measures first while still meeting regulatory standards that protect public health and water quality. Green infrastructure is a key integrated planning strategy for nutrient and stormwater management and enables management of stormwater as a resource and supports other economic benefits and quality of life. Integrated planning is being shown to have great cost-efficiencies through the comprehensive management of wastewater, stormwater and nonpoint sources throughout the nation. Why this Project? New Hampshire coastal communities have experienced rising populations resulting in an increase in development and stormwater and wastewater discharges to the Great Bay. As communities respond to new federal permit requirements for treating and discharging
foundation supported a Plan which could guide effective nutrient management in the region, and ultimately support attainment of permit requirements and ecosystem goals. The towns recognize the value of inter-municipal collaboration and have a long history of collaboration that augurs well for future collaborative success, and Integrated Planning for nutrient management could be a logical next step.
The Exeter wastewater treatment facility currently under design for upgrade stormwater and wastewater, meeting regulatory requirements requires innovative ways to find effective and affordable means to meet water quality goals. The neighboring towns of Stratham, Newfields, and Exeter, New Hampshire share a history of collaboration. They share a regional school district, management of hazardous waste, and town recreation programs. More recently, representatives from the Towns of Stratham and Exeter have been working together to discuss sharing water and wastewater infrastructure and services. Integrated Planning for nutrient management could be a logical next step. Management of Uncertainty Ecosystem restoration is an inherently uncertain process; ecosystem health and the role of nutrients and other impacts from urbanization are complex, and the time to recovery may be decades or longer. Some aspects of ecosystem response, such as chlorophyll-a reduction may occur very rapidly, while others, including long-term recovery of eelgrass have a much higher uncertainty. Permit requirements, on the other hand, require substantive assurance that goals will be met. EPA is required to issue permits that address a â€œreasonable potential to cause or contribute to impairmentsâ€?, while communities and residents naturally want a high level of confidence in the outcome of substantial investments in wastewater and stormwater. Long-term implementation schedules and adaptive management are means for communities and
regulators to manage uncertainty in environmental management. A long-term schedule combined with monitoring supports an iterative process of management actions which reduces uncertainty over time and has potential cost savings. The adaptive management process also provides a long-term strategy to address concerns about uncertainty in the understanding of the relative significance of nitrogen and its role in declining estuarine health. Town, Agency, and Stakeholder Collaboration This Plan was developed by a team of municipal leaders, engineers, scientists and agency representatives. It incorporates information and feedback from a wide range of stakeholders, and all participants have actively contributed to and reviewed these results. This collaborative
Technical Methods To understand the pollutant load inputs from the Squamscott-Exeter subwatershed to the estuary, a watershed-scale pollutant load model and budget were developed, which provides the average annual load to the estuary from nonpoint and point sources for the subwatershed and by Town. The pollutant load model was developed building on a number of existing studies and methods to account for surface water and groundwater loads to the estuary. The various components are: stormwater load model, septic system load model, agricultural load model, attenuation in pathways in groundwater and surface water; and wastewater treatment facility load model. The watershed model was developed using a hydrologic response unit (HRU) approach, idealized 1-acre representative parcels, with varying combinations of land use, soil type, and impervious cover. Precipitation data
A municipal bioretention system optimized for sizing for management of stormwater runoff 7
Agriculture and agri-tourism play an important role in the community from a local gage is used to perform a continuous rainfall-runoff simulation of the HRUs to estimate the amount of stormwater volume generated by each HRU. BMP and Source Area Optimization and Prioritization One of the core elements of integrated planning is the allowance that a permittee can take credit for actions associated with one permit (i.e., wastewater) and may also receive credit in another (i.e., MS4). For example, installation of green infrastructure (i.e., biofiltration to treat road runoff, or drywells to treat roof tops) for non-point source management under the WWTF permit could also satisfy requirements for in the draft NH Small MS4 permit .
This has the potential to be more economical than traditional permitting because it satisfies elements of both the MS4 and wastewater permits and it helps manage the uncertainty of environmental response. Optimization of designs used at the watershed scale can significantly reduce costs for achieving load reduction targets. This article will provide two case studies that use different cost minimization approaches. A linear optimization approach was used to find the lowest cost mix of nutrient control measures for nonpoint source, structural stormwater controls, agricultural practices, septic system retrofits, and variable water quality volumes. Optimal nutrient removal was achieved by targeting impervious surfaces that have the highest
load and greatest runoff potential, and sizing systems for the first flush of nitrogen enabling a substantial cost reduction. This approach allows for the use of various sizes (i.e., capture depths) of nutrient controls to allow for a greater number of smaller systems in place of fewer systems designed to treat larger volumes. The optimization model runs iteratively for different nitrogen control strategies with user defined constraints including available land for implementation, pollutant load reduction capability based on capture depth, and cost. This is first applied at the system level to develop a series of BMP performance curves. It is next applied at the land use scale to identify the most cost effective options for each
Optimization curve for residential land use illustrating the maximum point of cost effectiveness is small infiltration and biofiltration systems
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FPareto curves illustrating cost comparison of 1) integrated planning at the single municipality, 2) multiple community scale, versus 3) traditional permitting approach. particular land use. The optimization is then conducted at the watershed scale for the range of nutrient control measures, and the range of land uses. The optimization process is then repeated for various management scenarios. Major Findings Since 1960 Exeter, Newfields, and Stratham have experienced substantial population growth of 98%, 128%, and 602% and a 20 year increase in impervious cover of 108%, 177%, and 138% respectively. The Squamscott River has an average Total Nitrogen concentration of (0.77 mg/L), more than double draft criteria, and has lost 100% of its eelgrass cover since 1948. A new pending MS4 (stormwater) permit combined with a new 2012 wastewater permit substantially increases municipal requirements for nitrogen management.
10% for stormwater and 90% for wastewater both for construction and operation. Communities of Exeter, Stratham and Newfields contribute ~50% of the Nitrogen Load from 24% of the watershed area. Nearly 50% of the nitrogen load in the watershed comes from upstream communities, and water quality goals for the Squamscott-Exeter subwatershed cannot be attained without broader participation throughout the watershed.
ecosystem recovery in the Great Bay estuary which could fulfill permit requirements for a Nitrogen Control Plan. Municipal officials in each community could use the plan to guide local and watershed decisions around water quality and permit compliance. Detailed analyses of alternatives, calculated load reduction and associated costs, coupled with monitoring and tracking will be necessary to document progress and provide assurance that selected actions will support overall permit compliance and restoration goals. For the Integrated Plan to receive EPA approval some critical next steps will be required.
Project Contacts: Robert Roseen, Project Director firstname.lastname@example.org, Renee Bourdeau, Project Manager, email@example.com, Alison Watts, Watershed Science Lead, Alison. Watts@unh.edu, Paul Stacey, NERRS Research Coordinator, Paul.Stacey@wildlife.nh.gov, Cliff Sinnott, Executive Director Rockingham Planning Commission, firstname.lastname@example.org, Theresa Walker, Town Liaison, email@example.com, Jennifer Perry, Exeter DPW Director, perry@ exeternh.gov, Paul Deschaine, Stratham Town Administrator, firstname.lastname@example.org, Clay Mitchell, Newfields Town Planner planner@ newfieldsnh.gov
Next Steps This plan is intended to serve as a guide for the towns of Exeter, Stratham and Newfields to support nitrogen load reduction, permit compliance, and ultimately
An Integrated Planning approach that satisfies elements of both the MS4 and wastewater permits reduces existing loads by 60% (56 tons N) and was estimated to provide around 50% cost avoidance from traditional permitting for the three communities. The incremental cost to increase reduction from 53 to 74% for nitrogen load by WW and NPS management is an increase in $159 million (62% increase). Watershed wide, estimated costs are approximately
WISE Project Team during kick-off meeting. 9
(continued from pg. 1)
raising the high water mark for storms and peak tides. The magnitudes and permanence of those three items need to be evaluated separately and in combination. Global average sea level – the oftencited metric – misses a vast range of regional variation due to ground subsidence and changing ocean currents. Areas like Hampton Roads and New Orleans have dramatically greater SLR than the global average. For example, the rise in global average sea level over the past century has been approximately 8 inches; however, in New Orleans the rise has been over 45 inches. Internationally the list of extreme SLR areas is even greater with major cities as Tokyo and Jakarta near the top. Engineering also needs to take into account other local geologic and morphologic factors. Rising sea level combining with storms and extreme tides, presents different problems in different places. What works in Manhattan will not work in Miami for example. Unlike the damage from storm waves that are somewhat limited to the coastline, SLR extends through marshes and wetlands and can push hundreds of miles up tidal rivers greatly expanding the vulnerability zone. For example, Sacramento, California is located on a tidal river and is extremely vulnerable to sea level rise although it is over 80 miles from the coast. Wider community and peripheral vulnerability needs to be considered. For example, perhaps a building has adequate elevation and design to maintain functional use when sea level is three feet higher. But what about the access roads, utilities, or distant zone of vulnerability that could make the building indirectly vulnerable or even become a virtual “island” due to submerged areas outside the project boundary. What would that do to the value of the asset? Where would the blame fall for inadequate project design? Problems are not just limited to flooding. For example, sustained higher sea level will change the critical clearance heights
for vessels getting under bridges where tolerances are now sometimes measured in inches. It will also mean groundwater penetration into landfills, fresh water aquifers, toxic waste sites, and cemeteries posing new situations for public health and safety. 6. “Future technology” is often cited as the solution to the problem of SLR, yet sober evaluation shows that to be little more than wishful thinking. As one example, in a recent article in the New Yorker, the head of engineering for Miami Beach said that when sea level had risen beyond the capability of pumps, that perhaps they would lift up the entire city and install an impermeable barrier, or inject grout into the porous limestone. Most engineers would find those two suggestions to be completely unrealistic considering the large geographic area. Although innovation and new technologies will certainly play a part in SLR adaptation measures, engineers must understand their limitations when protecting vast assets and landmasses, urban as well as rural. 7. Efforts like the recent climate negotiations in Paris, known as COP-21, are commonly perceived to be a potential solution to SLR. As I explained in a blog post, “Paris Climate Agreement – the good, the bad and the ugly“ the 196 countries only agreed to limit maximum global warming to 2.0 degrees Celsius over pre-industrial, but could not agree on a method to reach the goal. Even if the agreed target can be reached, basic physics and thermodynamics guarantee that vast additional amounts of land ice will melt, raising sea level much higher. Engineers need to recognize that despite these very worthwhile efforts to reduce greenhouse gas (GHG) emissions and the various sustainability efforts, so much excess heat has already been stored in the oceans that we are now committed to substantial SLR with no hope of avoidance. We have passed a tipping point. (It must be noted of course that if we do not reduce GHG emissions and slow
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the warming, that SLR will accelerate and be dramatically worse, potentially catastrophic within this century.) 8. Sea level rise is now in motion. Our planning and design methods, so engrained with the notion of a fixed sea level, need to be updated. We need a new standard of practice. 9. Our building codes, even in the most progressive locations, do not adequately address the risk of SLR. As the engineering and planning industry as well as the general public become more aware of the risks from sea level rise, professionals can no longer expect to enjoy safe harbor from professional liability in designing and building only to code. What engineers and planners must do now: • Get informed and know the facts. Understand how SLR will impact your specific area of expertise. • Assist your clients in assessing the vulnerability of future projects. Today, there are new tools that can make this easy to do. For example, at the Rising Seas Group we work with engineers helping them understand the full array of design scenarios through a “9 box matrix” that plots short, medium, and long term time horizons against the realistic low, medium, and high scenarios for flooding from rising sea level, combined with the impacts from storms and extreme tides. Different locations and clients will have different time horizons and risk tolerance. This tool allows for a full range of scenario planning and vulnerability assessment. • Seize the opportunity to be seen as a leader. Sea level rise is a long-term trend that will bring tremendous economic growth and engineering opportunities. As businesses and communities continue to realize the necessity of SLR adaptation, enormous projects will be undertaken to build resilient communities. Now is the time to be on the forefront of SLR
adaptation planning, building and design. It is time for the professional engineering community to help educate clients about the issues of sea level rise, rather than just accepting the design criteria in an RFP. We are in the early stages of recognizing the revolutionary reality of sustained and accelerating sea level rise. It may be useful to look at the dual perspective of being on the forefront of new knowledge, as well as making sure that professionals will be able to defend against future allegations of possible negligence or other liability. Enlightened understanding could not only give us more resilient communities, and achieve better return on investment (ROI), it could enhance the scale of a project and reduce future exposure and establish the professional or the company as one that is forward thinking and a leader.
John Englander is President of the Rising Seas Group, a consulting practice that works with professionals, businesses, communities and government agencies to better understand, plan, and adapt to rising sea level. www.risingseasgroup.com email@example.com
CLOUDBURST MITIGATION Steven Roy, Climate Adaptation and Green Infrastructure US Service Line Martin Vilhelmsen, Project Manager, Rambol Christian Nyerup Nielsen, Global Service Line Manager Climate Adaptation and Green Infrastructure Climate is changing and the future extreme precipitation events will increase in frequency and intensity. Work is underway in several European cities to manage runoff during extreme events using new planning and engineering techniques. In 2010 and 2011, the City of Copenhagen— the capital of Denmark—was hit by three devastating cloudbursts in a 12-month period. During one extreme event on July 2, 2011 the intensity of precipitation was measured at 100 mm (close to 4 inches) in one hour. Major roads and other infrastructure were flooded. The total damage from the most destructive of the three events cost Copenhagen more than €800 million (or $1.18 billion). Climate is changing and the future extreme precipitation events will increase in frequency and intensity. Work is underway in several European
cities to manage runoff during extreme events using new planning and engineering techniques. In 2010 and 2011, the City of Copenhagen— the capital of Denmark—was hit by three devastating cloudbursts in a 12-month period. During one extreme event on July 2, 2011 the intensity of precipitation was measured at 100 mm (close to 4 inches) in one hour. Major roads and other infrastructure were flooded. The total damage from the most destructive of the three events cost Copenhagen more than €800 million (or $1.18 billion). As a consequence, the city embarked on the creation of a Cloudburst Management Plan, http://en.klimatilpasning.dk/media/665626/ cph_-_cloudburst_management_plan.pdf to invest in preventing flooding rather than
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responding to flooding damage on a regular basis. An initial economic analysis indicated the cost of doing nothing would triple in 100 years due to climate change affecting weather patterns, so the city decided it had to do something to protect the city from future damage. The plan The 2012 cloudburst master plan is based on a few simple principles, the main one being to keep the water on the surface and control it rather than making large expensive pipes underground. New infrastructure will be used for separating rainwater from smaller events to divert stormwater runoff from the sewers and wastewater treatment plants. From a socioeconomic perspective, this proved more feasible compared to conventional pipes, underground retention structures, and a completely new separate system. Adaptive measures on the ground surface will collect, detain and slowly release captured stormwater. A green solution helps by creating new recreational areas including new tree plantings that provide multiple benefits year round. Creating new pathways for directing and discharging stormwater to the ocean are planned. The plan will require implementation over a 20-year timeframe. Cloudburst streets collect and transport the water away from the vulnerable areas. Retention streets are typically located a bit upstream from a low-lying vulnerable area and retain the water through the large storage volumes created. Adjacent to the cloudburst streets, areas with secondary streets will be transformed into green streets with swales or permeable pavements that retain the water in the area, and to some extent, infiltrate it, thus helping to recharge the groundwater aquifers. Central retention will be created in public spaces like parks and parking zones. In areas where the water simply cannot be handled on the surface, large underground cloudburst tunnels up to three metres in diameter will
be built instead of cloudburst streets. This is mainly reserved for ultra-urban areas with predominately built and impervious surfaces. The master plan intends to create synergy for the city as a whole, achieved by using watersensitive solutions to increase the overall livability of the city, with the water on the surface used as a resource in the city space. The benefits are many, such as increased recreational value from the upgrading of parks and meeting places, improved microclimate, and synergy with traffic planning. More specifically, the concept is to retain the water in the upper drainage areas of the city and slowly release it when the peak of the storm has passed. In addition, the plan aims to create robust solutions that drain the low-lying areas. Where possible, the water should be handled locally. An extensive hydrogeological assessment of the whole city was conducted to identify the effects of infiltration on the groundwater table and to prioritize possible projects and solutions. Detailing the vision Copenhagen has been divided into eight areas, and an implementation plan for each of those catchments has been developed. Ramboll Environ prepared four of the eight implementation plans with detailed illustrations and renderings of how cloudburst streets, retention streets, and green streets can be designed, and how these solutions support the overall goal of the city to increase livability. Multifunctional spaces are key elements in the implementation plans, such as parks and playgrounds that can be flooded during heavy rainfall but in dry weather serve as recreational spaces. In one example of a multifunctional space on a cloudburst boulevard (see illustration), the boulevard is wide enough to have a substantial retention volume in order to both store the water and transport it away. As it stands currently, the street is a traditional
www.asce.org/ewri • EWRI Currents Volume 18 Number 1 Winter 2016
boulevard with a green median, which is common all over the world. The median is raised and has no other function than adding some green space to the city and providing space for the citizens to walk their dog. During cloudbursts, the water is likely to run from the green area and onto the street. The whole road profile is sloping toward the buildings and does nothing to prevent the basements under the houses from flooding. The vision Ramboll created for this boulevard is to change the whole road profile to a V-shaped profile, creating a large retention volume in the lowered green area in the center of the profile. When it rains, the water can run away from the houses and the street into the green area. The capacity of the urban river created during cloudbursts can carry up to 3.3 cubic metres of water per square metre. During normal rain and dry weather, the lowered green strip can serve recreational purposes. Central retention is also a key element in the plan. One of the more radical suggestions is to transform one of Copenhagen’s three innercity lakes, Saint Joergens Lake, into a beach park by lowering the water level in the lake. This creates a vast area for the collection of rainwater while also improving the recreational value of the city. The alternative would be to construct a gigantic and expensive cloudburst pipe to divert the expected half -million cubic metres of water away. The recreational solutions above ground will save approximately €44 million compared to the construction of an underground stormwater pipe. Benefits A socioeconomic analysis was done for the master plan, and the result was that the benefit from this approach exceeds the costs of construction and maintenance. Even though the budget is €1.3 billion ($1.9 billion) over a 30-year investment period, the benefits from prevented flooding and reduced damages far exceed the investments. In 2015, several hundred projects were approved and several
projects have already commenced. The implementation plans help Copenhagen maintain its position as one of the most livable cities in the world. The city is a showcase for the importance of long-term city planning and holistic and sustainable solutions, as well as an example to follow for many other cities in the world that are facing the same issues. Adapting to climate change in this way is good business for cities because of the many socioeconomic benefits. However, the costs of investing in cloudburst adaptation are also hard to finance. US cities are limited in their income and many local governments rely on real-estate taxes and limited state and federal government funding for their infrastructure investments. And no government grant is currently directed at â€œclimate adaptation.â€?
stormwater adaptation. Green infrastructure creates places that handle water and are, at the same time, attractive public spaces. Green infrastructure helps increase the value of nearby real estate by as much as five per cent, which makes it interesting for realestate developers to participate in adaptation investments. In order to attract private investors and work fully across departments to raise finances to avoid the cost of doing nothing, cities must understand the full benefits of doing something and capitalize on these benefits, as Copenhagen has done
Prepared by: Steven Roy, Climate Adaptation and Green Infrastructure US Service Line Manager, Ramboll-Environ T 978-449-0356 firstname.lastname@example.org Martin Vilhelmsen, Project Manager, Ramboll Christian Nyerup Nielsen, Global Service Line Manager Climate Adaptation and Green Infrastructure, Ramboll
Itâ€™s therefore paramount to look for ways to engage the private sector to attract funding and to work across departments to finance
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BOARDMAN RIVER DAMS DISPOSITION AND ECOSYSTEM RESTORATION PROJECT Dan DeVaun, PE – AECOM, Troy Naperala, PE – AECOM, Frank Dituri – Grand Traverse Band of Ottawa and Chippewa Indians, Kim Balke – Conservation Resource Alliancer
Many communities are struggling with aging infrastructure. Dams were built throughout North America during the 1900s to power industry and literally turn the lights on. Whether the dams were constructed for generating electricity, powering mills, controlling floods or providing recreational opportunities, many have exceeded (or are rapidly approaching); their expected lifespan and their owners are faced with rising maintenance costs and regulatory compliance issues. For many dam owners, removing the dam is the best option. The Boardman River Dams Disposition and Ecosystem Restoration Project in Michigan is an example of a process one community took to make this decision. The Boardman River flows into West Grand Traverse Bay of Lake Michigan at Traverse City, Michigan. The majority of the Boardman River is a high-quality coldwater trout stream that has been degraded in its lower reaches as a result of habitat conversion resulting from the construction of dams that once produced hydroelectricity. The 287 square mile Boardman River Watershed, upstream of the dams, is a nationally significant resource
noted for its “blue ribbon” trout fishing and “natural rivers” designation. In the lower river, the dams have replaced the coldwater ecosystem with warm water habitat. This has resulted in habitat fragmentation and degradation, thermal disruptions, and thermally induced species disruptions. The dams also create a barrier between the river and Lake Michigan and preclude tributary spawning, foraging and protection for Great Lakes species. In 2005, Traverse City Light and Power determined that it was not economically feasible to produce hydropower at the Sabin, Boardman and Brown Bridge Dams- all on the Boardman River. The dam owners – the City of Traverse City and Grand Traverse County – organized a citizen-based Boardman River Dams Committee to gather community feedback, encourage community involvement, and manage an engineering and feasibility study to assess the environmental, economic, and social implications of retaining, modifying, or removing the several dams. After thorough review and discussion, the dam owners decided to remove the Sabin, Boardman, and Brown Bridge Dams and modify a fourth dam (i.e.,
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Union Street) that did not produce hydropower but serves as a sea lamprey control barrier. Brown Bridge Dam was removed in 2012. The current focus is on removal of the Boardman and Sabin Dams. Future phases will entail the development of plans to modify Union Street Dam. The Detroit District of the U.S. Army Corps of Engineers has been engaged in the project since its inception, in partnership with local partners, via the conduct of an Engineering Feasibility Study. The project has progressed through several phases. Among others, key components included a collaborative, stakeholder-driven process to evaluate a range of alternatives; a focus on natural channel design; a controlled drawdown approach; evaluation of flood risk protection the dams provided; evaluation of post-dam removal sediment transport mechanisms and their impacts on infrastructure; and the permitting process. Each of these critical phases is described below. A Collaborative Process Worth Emulating: Early in the project the dam owners set out to
cultivate a sense of ownership in the project by all stakeholders and interested parties, all in the interest of demonstrating sensitivity to community needs and concerns. This resulted in a community engagement process that lasted from 2005 to 2009. This process included cooperation among local, state, federal, and tribal government agencies, nonprofit organizations, and local residents. The result was an engineering and feasibility study that considered the environmental, economical, and social impacts of retaining, removing, or modifying the Boardman River Dams. Ultimately the dam owners decided to remove Brown Bridge, Boardman, and Sabin Dams while modifying Union Street Dam.
understand the condition and function of the structure being demolished. The goals of the dam breach design for the Boardman and Sabin Dams, are focused on efficiency and underscored by redundant safety measures. This redundancy carries over to the design process including geotechnical investigations, structural and geotechnical analyses, and extensive review processes including a collaborative risk assessment meeting. The resulting design takes into account the existing condition of the structure, hydrology of the region, sediment management, channel restoration design, and safety and risk considerations. The design developed for this project includes a siphon and pump system with an emergency overflow channel.
Natural Channel Design: Project stakeholders identified complete dam removal and restoration of the channel to its pre dam location as a high project priority. This lead the consulting teams to a design that restored the river to a condition that approximates its natural flow regime (i.e., with little or no man-made structures or influences). Achieving this goal is dependent upon substantial field investigations utilizing depth of refusal measurements to locate the historic channel, quantify sediment, and reference reach measurements to best approximate natural channel geometry. The construction phase of the project will entail “daylighting” the historic channel, allowing the river to reclaim its natural alignment.
Flood Risk Assessment: Of the 2,500 registered dams within the State of Michigan, very few were constructed to provide flood mitigation. However, when a dam removal is proposed, the first question to be asked is inevitably, “Will I be flooded if the dam is removed?” The answer to this question is dependent upon the river’s hydrology and the physical characteristics of the dam and its impoundment. This question has been asked numerous times throughout the Boardman River Dams Disposition and Ecosystem Restoration project, and has been carefully addressed by AECOM with regard to the upcoming removal of the Boardman and Sabin Dams. A thorough flood risk assessment was undertaken, providing a high level of confidence among project stakeholders that the dams historically functioned as run-of-the-river
Controlled Dam Breaching Design: When tasked with removing a dam, it is important to
and provided no significant flood mitigation. Sediment Transport Impacts to Infrastructure: One of the goals of the project is to restore natural sediment and nutrient transport through the river. However, a significant concern relates to the potential impact of increased sediment loads on infrastructure that has seen reduced loads for the past 100 years. These impacts were evaluated through a series of sediment transport and geomorphologic analyses that addressed both short-term increases in sediment loads (associated with restoration activities), as well as long-term sediment aggradation in delta areas and associated impacts to flood stage and flood plains. Outcomes of these analyses were taken into consideration in designing approaches to dam removal and informing dam owners of potential future maintenance activities. Permitting Process: The key to a timely and successful permitting process is early and continuous coordination and communication with all relevant federal, state and local regulatory and resource management agencies. This coordination eliminates (or minimizes the likelihood of) surprises and ultimately leads to a high quality restoration project in full compliance with various regulations. Key issues addressed through the permitting process include protecting existing wetlands (and those anticipated to form once the dams are removed), addressing material that is regulated as sediment during the initial phase of the project (and as soil at the project
completion), and floodplain/flooding concerns. Over the past 11 years, this project has progressed from a conceptual planning phase to an implementable project that has seen one dam removed and two more removals in the engineering design phase. Benefits have been realized as the project has unfolded: costly, aging and unsafe infrastructure is being removed, a more natural flow regime is being restored, and healthier, more natural aquatic ecosystems have been documented. The projectâ€™s momentum continues to draw new partners and inspire the long-standing ones. As it moves toward completion, the project demonstrates the multiple benefits of removing aging infrastructure, restoring a river, and generating benefits for the ecosystem and all who use it.
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www.asce.org/ewri â€˘ EWRI Currents Volume 18 Number 1 Winter 2016
USING DISTRIBUTED TEMPERATURE SENSING TO UNDERSTAND TEMPERATURE DYNAMICS AT SHASTA LAKE, CALIFORNIA Laurel Saito, University of Nevada Reno; Scott Tyler, University of Nevada Reno; Rachel Hallnan, University of Nevada Reno; Eric Danner, National Oceanic and Atmospheric Administration
The drought in the western United States has emphasized the need to manage water efficiently for multiple purposes, including the provision of adequate thermal habitat for endangered fish. In California, management of discharges from Shasta Dam is one of the tools to store cold water in the reservoir for release at times that are critical for salmon spawning and rearing. To better understand the temperature patterns upstream of the dam, a team from the University of Nevada Reno in collaboration with NOAA Fisheries has been using distributed temperature sensing (DTS) to monitor water temperature with depth in the reservoir. DTS measures the backscattered Raman photons along a standard telecommunication optical fiber. Raman backscatter can be related to the temperature of the fiber at the point of scattering, and therefore near-continuous profiles of temperatures can be obtained along any fiber (Selker et al. 2006; Tyler et al. 2009). Typical integration times of 60 seconds can provide temperature resolution of less than 0.05°C (Hausner et al. 2011). The technology has been used for many different applications including examining Antarctic ice shelf stability (Kobs et al. 2014), describing convective mixing at Devil’s Hole in Death Valley National Park (Hausner et al. 2012), and monitoring
heat generation in salt-gradient solar ponds (Suarez et al. 2014). In the pilot application at Shasta Lake, deployment of the DTS required careful consideration of secure deployment in close proximity to hydropower intakes with water levels that can fluctuate as much as 100 feet. The fiber optic cable is ~3/8” diameter, and has an outer shield of braided stainless steel. The breaking strength of the cable is ~ 1,000 lbs. The DTS detector was housed inside the dam, and the cable was routed through the dam and down the west side of the temperature control device (TCD) that allows selective withdrawal from the reservoir. Transmission of data from the TCD for the pilot deployment is via a cell modem. The sensing cable drops ~400 feet down through the reservoir in front of the dam. The pilot deployment successfully captured the decline of the reservoir thermocline as water levels dropped in the fall and the development of isothermal conditions in late November. Future work involves using the DTS data to understand reservoir dynamics as release operations change to enable predictive modeling of reservoir operations.
UNDERSERVED COMMUNITIES IN NEED OF WATER RESOURCES EXPERTISE Are you looking to volunteer your water resources expertise to help underserved communities? Consider Community Engineering Corps (CECorps), an alliance between ASCE, the American Water Works Association (AWWA), and Engineers Without Borders USA (EWB-USA). With its mission to bring U.S. underserved communities and volunteer engineering leaders together to advance local infrastructure solutions, CECorps offers you this hands-on opportunity. CECorps works only with communities who do not have the resources to access engineering services in a traditional fee-for-service manner. While there are several open projects waiting for adoption by a project team, one group of projects in particular would benefit from EWRI member involvement. CECorps, along with NGO partner the Environmental Justice Coalition for Water, is seeking project teams to assist eight rural, underserved communities in the Salinas River Valley in California. Help is needed to identify and evaluate solutions to water supply and sanitation problems, such as water systems and domestic wells being out of compliance with regulations regarding nitrate in their water supply and a waste water system that is out of compliance with county regulations. Project teams can be formed through your EWRI Chapter or an ASCE Section or Branch. The team must have at least one professional engineer licensed in the state in which the project will take place (CA) to serve as the Responsible Engineering in Charge. Learn more about the Salinas River Valley projects, additional open projects, and other volunteer opportunities such as reviewing community project applications or providing technical review of project plans. Engage with CECorps to provide pro-bono engineering services that address the infrastructure needs of underserved communities in the United States.
www.asce.org/ewri â€˘ EWRI Currents Volume 18 Number 1 Winter 2016
WORLD ENVIRONMENTAL & WATER RESOURCES CONGRESS 2016
West Palm Beach | May 22-26 2016 www.ewricongress.org
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EWRI Currents is written and published by the EWRI Communications Council, part of Membership Services. For membership opportunities, contact Chad Drummond at CDrummond@drummondcarpenter.com. Editor: Chad Drummond (407) 417- 1220 CDrummond@drummondcarpenter. com NEWS CORRESPONDENTS Irrigation and Drainage Council Robert Evans email@example.com
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