Aug. 2, 2012 Vol. 2, No. 8
Setting our Sights on Stormwater
By Mike Beezhold
WEF Stormwater Committee Chair
Hot temperatures and heavy rains didn’t dampen the spirits of the more than 360 stormwater professionals from around the country attending the inaugural Stormwater Symposium 2012 in Baltimore. Rather it emphasized the importance of stormwater management and energized good conversation, learning, and professional networking.
Participants made the most of current collective knowledge, insights, and experience in best managing stormwater—preparing for what many are calling “21st Century Water Infrastructure,” a combination of gray and green infrastructure. The U.S. Environmental Protection Agency addressed implications of the national stormwater rulemaking. Presenters shared case studies stressing the power of precipitation and its pollutant-carrying potential.
On the positive side, rain also has the potential to renew communities and help them prosper through progressive stormwater management by creating jobs, improving quality of life, and introducing green space for all to enjoy. Stormwater infrastructure is no longer “out of sight, out of mind” but is becoming a prominent feature.
For decades, stormwater management has received little dedicated funding, and now the externalities associated with business as usual and deferring maintenance costs have come home to rest. The theme of the 21st century is doing more with less. Communities are finding that going back to green is easing the pain and drain on the pocketbook while providing more community benefits with greater public acceptance.
The multiple benefits of 21st Century Water Infrastructure will far outweigh the costs for this generation and those to come. These themes were heard consistently throughout the symposium. For instance, during the Opening General Session, it was clear — from the small community of Rockville, Md., to the City Baltimore — that commitment to stormwater is a game changer for large and small alike.
Stormwater management is a necessary and “value-added” community service, and like all services, it must be paid for and operated as such. Stormwater infrastructure is an investment in a community’s future — in clean water, green jobs, and flood control. Many states, such as Maryland, are requiring communities to have sufficient funding to meet their stormwater obligations. There were several great presentations regarding the legal, social, and fiscal considerations of community funding options.
It was apparent that the profession of stormwater management has matured during the past 2 decades, enabling the symposium program committee to pick from just over 200 abstracts spanning the many facets of stormwater management. In fact, the conference planners were able to run three concurrent sessions on both days of the symposium, creating a solid program to enhance the stormwater practitioner’s toolbox. More than 75 presentations took place at the Stormwater Symposium 2012, and their quality reflected the careful review of the symposium program committee. Many thanks to the Water Environment Federation staff, symposium chairs, the steering and program committees, presenters, and, most importantly, the participants for a successful symposium.
Read short summaries of highlighted technical sessions from the 2012 Stormwater Symposium in the Symposium Notes section below. Also, discover more about WEF’s commitment to stormwater management and the Stormwater Committee. We look forward to continuing these conversations and seeing many of you at WEFTEC® in October.
WEFTEC Stormwater Programming Continues to Expand
The Water Environment Federation (WEF) will host WEFTEC® 2012 Sept. 30 – Oct. 3 at the New Orleans Morial Convention Center. WEFTEC will include more than 75 presentations dedicated to stormwater, with programming in every time slot. In addition to sessions, there will be 3 workshops covering green infrastructure, funding, and linking stormwater controls to receiving waters. Located in Hall E, WEFTEC’s first ever Stormwater Pavilion will feature over 30 exhibitors in over 8500 square feet. The exhibitors in this area will be displaying the latest equipment, supplies and services for stormwater management.
Check here for a full list of stormwater programming, including committee meetings, workshops, technical sessions, and more. Online registration is open now. Also, find information on how to get employer approval to attend.
U.S. EPA To Provide $950,000 for Green Infrastructure Implementation in U.S. Communities
At the 2012 Stormwater Symposium, the U.S. Environmental Protection Agency announced that it will provide $950,000 in technical assistance to 17 communities across 16 states for expanding the use of green infrastructure. These cities represent the second round of green infrastructure community partnerships. Read more.
WEF Announces Top Stormwater Videos at 2012 Stormwater Symposium
The Water Environment Federation (WEF) collected more than 35 videos via the Stormwater Call for Media, an effort to collect and share innovative stormwater projects. The top two videos aired at the 2012 Stormwater Symposium. Under One Umbrella, by KPFF Consulting Engineers, features a bioretention area that is also a stormwater fountain and community gathering space anchored by giant bronze umbrellas. GreenTreks, a Philadelphia-based nonprofit communications organization, submitted the other top video — StormwaterPA: Low Impact Development. Rather than use a traditional stormwater management approach, this video focuses on a 24-ha (59-ac) residential community that has incorporated a system of more than 100 low-impact development measures to maximize infiltration of runoff at the site level.
Find all videos on WEF’s stormwater playlist, then go to the poll to vote for your favorite! Top videos will be shown at WEFTEC® 2012.
Brief summaries from select presentations made at the Stormwater Symposium 2012.
Papers behind these presentations and nearly 75 others make up the Conference Proceedings, which can be obtained by calling (800) 666-0206. Ask for stock number CPSW 1207. The member rate for proceedings is $US75, and the nonmember rate is $US115.
Capitol Region Watershed District Measures Cost and Performance of 18 Stormwater Controls
Presenter: Mark Doneux, Capitol Region Watershed District
Session 03: Stormwater Controls
In 2006, the Capitol Region Watershed District (Saint Paul, Minn.) began the Arlington Pascal Stormwater Improvement Project. This $2.7 million project included a performance and cost analysis of 18 stormwater controls (SWCs) during a 4-year period. SWCs included rain gardens, infiltration trenches, underground storage, and a pond. Here are a few highlights from the district’s study:
- SWCs captured approximately 20% of annual rainfall in the 121-ha (299-ac) Como Subwatershed.
- The rain garden, infiltration trenches, and underground storage had volume-reduction, total phosphorus (TP), and total suspended solids (TSS) removal efficiencies of nearly 100% for three of the study years, excluding 2010, which was a particularly wet year.
- Cumulative TP load reductions averaged about 73 kg (161 lbs) per year, which greatly exceeded target TP load reductions.
- While the pond received the most runoff, TSS, and TP, it had the lowest removal efficiencies.
- During the 4 years, operation and maintenance of the 18 SWCs cost about $22,000 and 554 labor hours. While annual labor costs decreased over time, projected annual operation and maintenance costs are higher in order to account for large-scale maintenance.
- Annually, volume-reduction costs for individual SWCs ranged from $0.75 to $2.99/m3. The underground chamber and pond removed TP and solids at the lowest cost, while infiltration trenches and rain gardens were more costly.
This study is also included in Banking on Green, a recently released report on green infrastructure co-authored by American Rivers, the American Society of Landscape Architects, ECONorthwest, and the Water Environment Federation.
University of Alabama Studies Best Practices for Measuring Infiltration Rates
Presenter: Robert Pitt, University of Alabama
Session 07: Stormwater Data
Low infiltration rates are often caused by compaction and can impair the effectiveness of green infrastructure practices, particularly in clay soils. In Tuscaloosa, Ala., Redahegn Sileshi and other researchers from the University of Alabama tested soils devastated by severe tornados. The goal of this study was to develop a method of quickly testing bioinfiltration rates that would be legitimate over both the short and long term. This can help improve the reliability of stormwater control practices and identify problem areas.
The researchers found that for testing surface infiltration— in grassed swales, for example —small-scale infiltrometers work well. In contrast, conventional double-ring infiltrometers require excessive force, as well as large volumes of water. The method is also time-consuming. For measuring subsurface conditions, researchers discovered that the borehole or “Sonotube” test works if a borehole drill rig and large amounts of water are available. If an infiltration-based practice is already established, a pressure transducer with a data logger can determine infiltration during an actual rain event.
U.S. EPA Survey of MS4s Informs Stormwater Rulemaking Effort
Presenter: Holly Galavotti, U.S. EPA Office of Water
Session 11: MS4 Permitting and Codes
In 2008, the U.S. National Research Council found that current regulations were not fully addressing nonpoint source pollution. As part of U.S. Environmental Protection Agency (EPA) stormwater rulemaking efforts, the agency collected data from nearly 850 municipal separate storm sewer systems (MS4s), including regulated, nonregulated, and transportation MS4s.
Results showed that 61% of the 222 regulated Phase II MS4s surveyed have stormwater programs that cover their entire jurisdiction. They also found that 14 states require jurisdiction wide stormwater programs, even if only a portion of the jurisdiction is in an urbanized area. Furthermore, 64% of Phase II MS4s and 80% of the 249 surveyed Phase I MS4s have either numeric or specific post-construction standards or design criteria for stormwater controls. Finally, 41% of Phase I MS4s and 18% of Phase II MS4s are implementing stormwater retrofit programs.
EPA is still reviewing financial and cost data from the survey.
Fort Wayne, Ind., Uses Green Scorecard To Evaluate CSO Control Alternatives
Presenter: Aaron Hutton, Malcolm Pirnie, the Water Division of ARCADIS
Session 06: Cutting-Edge Research
The City of Fort Wayne, Ind., evaluated 17 alternatives for controlling combined sewer overflows. Using a “Green Scorecard,” the city looked at three asset-management-only alternatives, as well as six gray-only, two green-only, and six hybrid green–gray alternatives.
The scorecard is broken into economic, social, and environmental impacts based on a triple-bottom-line approach. The city also identified 22 metrics, such as capital cost, job creation, and flood protection, and weighted them based on the city’s objectives. The city scored each metric, generally from 1 to 5, with 5 being the best — highest benefit, lowest cost, or lowest risk. However, metrics could get a zero if they were not applicable or a negative score if they worsened a problem. The Green Scorecard results were fairly balanced, recommending one asset management, one green-only, and two hybrid solutions. See an example of the Green Scorecard.
LID Assessment Tool Enables Users To Quickly Compare Alternatives
Presenters: Christopher Behr, HDR Engineering Inc., and Franco Montalto, Drexel University
Session 16: Examining the Cost of Green
Low Impact Development Rapid Assessment (LIDRA) Version 2.0—a free Web-based planning model developed at Drexel University — is useful for quantifying uncertainty related to green infrastructure performance, costs, demand, and benefits. LIDRA provides a stormwater control’s overall cost-effectiveness by coupling a life-cycle cost analysis with a performance analysis. Users can vary green infrastructure adoption rates and compare its use on various land and street types while utilizing costs from national data sets. The resulting information can improve informed decision-making, and due to its rapid assessments, LIDRA is also useful for comparing alternatives during the public participation process.
Stream-Channel Protection Requires Focus on More Than Flow Magnitude
Presenter: Robert J. Hawley, Sustainable Streams
Session 25: Vigilance in Monitoring and Maintenance
According to Robert Hawley — principal scientist at Sustainable Streams — adequate stream-channel protection requires stormwater controls that are designed with local data to address not only peak flows but also the frequency and duration of erosive flows. Channel instability is generally caused by an increase in runoff often associated with increased impervious urban cover. The impact from higher runoff rates occurring at an increased frequency can be exacerbated by the increased duration of erosive flows released by conventional stormwater basins. The resulting erosion adversely affects stream habitat and infrastructure located in riparian areas.
In a Northern Kentucky watershed, Hawley and other researchers showed that post-development erosive flows lasted 500% to 1000% longer and had the capacity to transport about 2700 Mg (2976 tons) of sediment over a 57-year continuous simulation of actual rainfall. This is nearly 17 times the capacity of the predeveloped watershed, which could only transport about 160 Mg (176 tons) of sediment during the same period. Small increases in impervious area could be responsible for significant stream destabilization. In Southern California, Hawley found that watershed development of 15% impervious area was correlated to fivefold increases in channel cross-sectional area. Even in more-resilient stream systems of Northern Kentucky, recent research showed channel enlargement rates of about 0.4 m2 (4.3 ft2) per year for every 5% increase in watershed imperviousness.
Blue and Green Roof To Serve As a Green Jobs Training Opportunity
Presenters: Jennifer Cass and Sandeep Mehrotra, Hazen and Sawyer
Session 24: Keep It Out of the Sewer
The Osborne Association’s 100-year-old Osborne Green Career Center in South Bronx, N.Y., will soon be outfitted with a blue and green roof. The new roof will become part of the center’s green jobs training program for the formerly incarcerated. Trainees will learn how to maintain the roof and monitor its effectiveness. The roof will be paid for in part by the Osborne Association and the New York City Department of Environmental Protection's Green Infrastructure Grant Program (see the winners). Each year, the roof should manage more than 908,000 L (240,000 gal) of stormwater with the goal of reducing combined sewer overflows to the East River.
Blue roofs are a fairly new technology. They are non-vegetated but detain stormwater for gradual release. The Osborne Green Career Center’s blue roof will be composed of aluminum trays, geotextile, and crushed stone. According to presenters, blue roofs typically cost less than green roofs. In addition, blue roofs generally require less maintenance and have a reduced deadload of approximately 73 kg/m2 (15 lb/ft2), compared to vegetated roof systems under dry conditions. However, green roofs provide additional benefits, such as carbon storage, reduced heat-island effects, and more.
In Public Outreach Success Story, City of Salem, Ore., Creates Stormwater Utility
Presenter: Robert D. Chandler, City of Salem, Ore.
Session 14: Funding Issues
In Salem, Ore., stormwater services were funded primarily by wastewater ratepayers. However, Salem’s Public Works Department (PWD) wanted to create a dedicated funding source for stormwater services that would better reflect the link between service costs and customers’ impacts on the stormwater system. The rate system, based on impervious surface area, meant that some customers, such as government offices, churches, schools, and commercial properties, would be significantly affected. This was compounded by the recession and the city’s 10.7% unemployment rate. However, in Dec. 2010, in a 6–2 vote with one abstention, the Salem City Council passed the measure to create a stormwater utility. The city even received positive comments from the media in the Statesman Journal. PWD attributes its success to an aggressive 12-month outreach effort.
PWD not only reached out to stakeholders but engaged and created relationships with them. PWD made changes to its proposed rate structure and other aspects of the program based on feedback, particularly from a Water/Wastewater Task Force made up of elected officials and utility customers. PWD consistently conveyed three simple talking points and created “frequently asked questions” documents, reports, and presentations. It targeted outreach efforts toward customers who would be most affected, acknowledging impacts and risks and trying to reduce them where possible. Another key to success was an educated electoral body actualized through meetings with the chamber of commerce, work sessions, and a two-part public hearing with the City Council.
Check It Out!
Victory Brewing Co. — which provided refreshments at the 2012 Stormwater Symposium reception — awarded the Guardians of the Brandywine with its Headwaters Grant. Guardians of the Brandywine used the grant to promote creek stewardship through a photography contest and educational session on stream monitoring. Check out the winning photos and a video on the program.
Brandywine Valley Association also received a grant to host a community tree planting and restore eroding streambanks in Parkesburg, Pa. “The pure water flowing from our local watersheds allows us to create the flavorful beers that we are so proud of,” said Victory Brewing Co. President Bill Covaleski. “Therefore, it was an obvious step for us to give back and protect this vital resource which was so generously provided to us.”