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 storm events 

 WEF Events 

Design of Urban Stormwater Controls MOP Series
July 12, Aug. 9
1–2:30 p.m. (EDT)
A no-charge webcast series 
 

 WEF/CWEA Stormwater Symposium 2012
July 19–20
Baltimore 
 

WEFTEC 2012
Sept. 29–Oct. 3
New Orleans

 

Member Association Events 

New York Water Environment Assoc.
2012 Watershed Science and Technical Conference 
West Point, N.Y.
Sept. 13–14

 

Other Events 

U.S. EPA
USDA’s National Water Quality Initiative
July 10
1–3 p.m. (EDT)
Part of EPA’s Watershed Academy webcast series 


North Carolina State University
Low Impact Development Researcher Symposium
Aug. 13–14
Asheville, N.C.


Australian Stormwater Industry Association
Stormwater 2012
Oct. 15–19
Melbourne, Australia

 

  July 5, 2012                                                Vol. 2, No. 7  

 storm feature 

 

 

 
Subsurface Gravel Wetlands for Stormwater Management
 
By Robert M. Roseen, Thomas P. Ballestero, James Houle, and Alison Watts 
University of New Hampshire Stormwater Center  

Subsurface gravel wetlands are a recent innovation in low impact development stormwater design that offer a high level of treatment for nonpoint source pollution. Their gravel substrate creates an anaerobic, microbe-rich environment, making them particularly well suited for nutrient removal. This capability makes gravel wetlands ideal for areas with impaired receiving waters and nutrient total maximum daily loads.

Subsurface gravel wetlands approximate the look and function of natural wetlands, with a high performance for removing sediments, nutrients, and other pollutants commonly found in runoff.

Gravel wetlands combine sedimentation on the surface of the system and microbial nitrogen removal in an anaerobic subsurface zone with physical filtration. The result is highly effective advanced stormwater treatment.

 Gravel wetland design thumb 
Concept schematic for subsurface
gravel wetland. Click to enlarge.
Based on 6 years of performance data collected by the University of New Hampshire Stormwater Center (UNHSC), average nitrate removal in gravel wetland systems is greater than 75% annually and 85% in the summer. The wetlands remove more than 95% of total suspended solids and have a phosphorus removal efficiency of 58%. In addition, seasonal performance evaluations show these systems to have a high level of functionality during winter months.

Originally developed for use in wastewater treatment, the Center for Watershed Protection introduced gravel wetlands for stormwater management in 1996. Initially, their implementation was minimal. However, usage is growing because of their documented exceptionally high level of treatment, especially for nutrients.

 

wetland actual thumb 
View across gravel wetland from outlet at commercial site, Greenland, N.H. Click to enlarge.
While similar in appearance, gravel wetlands should not be confused with constructed surface flow treatment wetlands, which are modifications of traditional ponds. The difference is the subsurface system that allows water to drain from the gravel wetlands, enabling them to function much like a dry pond. While the surface is dry between storms, the subsurface storage reservoir, filled with gravel, remains saturated and becomes anaerobic.

 

On the surface, wetlands are densely vegetated. Below the surface, gravel wetlands are composed of a series of flow-through cells consisting of wetland soil underlain by a thicker layer of angular stone or gravel. Stormwater typically enters the system through some form of pretreatment, such as a sediment forebay. Stormwater is then filtered and treated as it flows horizontally through the subsurface from cell to cell via gravity.

Although a wide range of research exists for biofiltration, much less is available on the use of subsurface gravel wetlands for stormwater management. For more than 6 years, UNHSC has been conducting performance monitoring for several subsurface gravel wetlands at a field site in Durham, N.H., and a commercial installation in Greenland, N.H.

 Gravel Wetland image thumb  
View of treated runoff from gravel wetland at commercial site, Greenland, N.H. Click to enlarge.

Studies at UNHSC show that, on average, gravel wetlands are able to reduce nitrate concentrations in treated effluent to less than 0.05 mg/L (0.05 ppm), phosphorus concentrations to 0.02 mg/L (0.02 ppm), and total suspended solids to 4 mg/L (4 ppm). While nitrate removal was highest in summer, gravel wetlands still performed well in winter, with a 33% removal rate. Studies also showed that maintenance of vegetation and removal of biomass every 3 years is important for maintaining high removal efficiencies.

Read more on subsurface gravel wetland design specifications from UNHSC.

 Storm news 

U.S. EPA Releases Stormwater Rulemaking Schedule  

/uploadedImages/Access_Water_Knowledge/Stormwater_and_Wet_Weather/Stormwater_Reports/stormdrain.jpg After several short extensions, the U.S. Environmental Protection Agency (EPA) released official dates for the National Stormwater Rulemaking: June 10, 2013 for release of the proposed rule and Dec. 10, 2014 for release of the final rule.  These dates are a result of negotiations between EPA and the Chesapeake Bay Foundation, as a letter of agreement signed between the groups established initial rulemaking milestone dates.  EPA is expected to continue work gathering information and analyzing costs and benefits on the rule through the summer and into the fall before assembling a draft proposed rule. EPA will likely submit the draft to the Office of Management and Budget in early 2013. EPA has not yet posted information reflecting these dates, please follow updates directly from EPA.

 

Nancy Stoner Keynote Speaker at 2012 Stormwater Symposium 

pondNancy Stoner, Acting Assistant Administrator for the U.S. Environmental Protection Agency (EPA) Office of Water, will be part of the 2012 Stormwater Symposium Opening General Session.  Stoner will speak to timely issues, such as EPA’s integrated planning framework, national stormwater rulemaking, EPA’s green infrastructure strategy, and the Campus RainWorks competition.  Other topics to be addressed by panelists and speakers will include recent U.S. Supreme Court activity and interest in stormwater-related issues, financial challenges municipalities and utilities face in managing stormwater, and future research needs in the stormwater field.       

 

U.S. EPA Releases Integrated Planning Framework for Stormwater and Wastewater 

storm drainOn June 12, the U.S. Environmental Protection Agency (EPA) released its revised Integrated Municipal Stormwater and Wastewater Planning Approach Framework. The framework does not lower existing regulatory standards but allows municipalities to prioritize stormwater and wastewater projects. The framework is designed to help municipalities better manage the costs of implementing Clean Water Act requirements. Rather than implementing stormwater and wastewater requirements separately, the framework encourages municipalities to identify complementary and innovative solutions, such as green infrastructure.

EPA held a series of public workshops on the framework earlier this year. The revised framework incorporates comments from these workshops by adding a new element on adaptive management approaches, placing more emphasis on public outreach, addressing prioritization more effectively, providing more detail on cost and affordability, and explaining the balance between permitting and enforcement.

The Water Environment Federation recently hosted a webcast on the framework and will host a second webcast describing case studies of implemented integrated plans. View the slides only. 

 

 WEF Awarded Green Streets–Green Jobs–Green Towns Grant  

On June 27, the Chesapeake Bay Trust, U.S. Environmental Protection Agency (EPA), Maryland Department of Natural Resources, and Maryland Department of the Environment announced that the Water Environment Federation (WEF) is among the 10 winners of their Green Streets–Green Jobs–Green Towns Grant. The grants include $376,000 supporting stormwater management, green job development, and enhanced resident livability throughout the Chesapeake Bay watershed.

WEF’s winning project proposal is for a 2-day event and field trip on low impact development (LID) competitions in EPA Region 3. LID competitions are an effective way of positively engaging the land development community in implementing green infrastructure. The event will bring together groups currently involved or interested in LID competitions. The goal is to facilitate information sharing and develop guidance and support from early adopters.

 

 U.S. Supreme Court To Review Stormwater Cases 

The U.S. Supreme Court will review two stormwater cases from the 9th U.S. Circuit Court of Appeals. The first is the 9th Circuit Court’s decision to consider stormwater runoff channeled from logging roads as a point source, requiring a Clean Water Act permit. This overturns 30 years of regulatory status quo, as the U.S. Environmental Protection Agency traditionally requires best management practices for nonpoint source pollution. Read more.

The Supreme Court will also review a case from the Los Angeles County Flood Control District. According to the 9th Circuit Court, Los Angeles County is responsible for the polluted runoff released into the Los Angeles and San Gabriel rivers from its storm drains. The Supreme Court will clarify whether water flowing from a man-made channel into a natural portion of the same river constitutes a "discharge" from an "outfall" subject to a National Pollutant Discharge Elimination System permit. Read more details in The Stormwater Report Vol. 1 No. 6 and Vol. 1 No. 8.

 

WEF Releases Manual on Design of Urban Stormwater Controls   

The Water Environment Federation and American Society of Civil Engineers recently released Design of Urban Stormwater Controls. This Manual of Practice walks readers through setting water quality performance goals and selecting the right stormwater management practice and design to meet those goals. The manual covers the design of basins, swales and strips, filters, infiltrators, gross pollutant traps, and mechanical operations. It also discusses how to maintain stormwater controls and assess their performance, so they continue to provide adequate storage and pollutant removal efficiencies over their useful life spans.

 

 U.S. EPA Releases Fact Sheets on Green Infrastructure and Watersheds  
 
The U.S. Environmental Protection Agency (EPA) recently released a series of six fact sheets and four supplements on incorporating green infrastructure into control programs. The fact sheets are part of EPA’s permitting and enforcement series and cover general accountability considerations, combined and sanitary sewer overflows, stormwater, total maximum daily loads, and water quality standards.

In June, EPA also released a fact sheet on the economic benefits of healthy watersheds. Maintaining a healthy watershed enables ecosystem services, such as stormwater infiltration and natural disaster resiliency, to operate free of charge. For example, flooding in the U.S. causes an average of $8 billion in damage every year, some of which could be avoided by maintaining natural land cover, according to EPA. The fact sheet compares the cost of nature’s services with those of man-made treatment works. Healthy watersheds also increase property value and recreational activities.

 

U.S. EPA Issues CSO Post-Construction Compliance Monitoring Guidance    

Regulated communities are expected to develop Long Term Combined Sewer Overflow (CSO) Plans as part of the 1994 CSO Control Policy. One requirement of the long-term plan is drafting a post-construction compliance monitoring program. The U.S. Environmental Protection Agency recently released a guidance document to help with this step. The guidance focuses primarily on verifying compliance and determining the effectiveness of CSO controls.

  

 WERF Announces Call for 2012 Unsolicited Research Proposals   

The Water Environment Research Foundation (WERF) is seeking proposals related to wastewater, stormwater, and water quality for its 2012 Unsolicited Research Program. WERF will consider new research ideas, as well as those building on existing research. Those interested should check the WERF website for a list of ongoing, completed, and planned research to avoid duplication. Preproposals are due to WERF by July 12 at 5 p.m. EDT.

 

WERF Releases Guidance on Using and Evaluating Innovative Stormwater Controls   

In June, the Water Environment Research Foundation (WERF) released two stormwater publications that are available free to WERF subscribers. The first, Tools For Evaluating The Benefits Of Green Infrastructure for Urban Water Management, discusses criteria, metrics, and protocols for measuring green infrastructure benefits. This discussion includes data collection and performance measurements, as well as two important cost analyses — triple bottom line and life cycle cost analysis.

WERF also recently released Stormwater Non-Potable Beneficial Uses and Effects on Urban Infrastructure. This publication covers international beneficial stormwater use projects in both developed and developing countries under various climatic conditions. It also discusses stormwater storage and treatment options for meeting water quality criteria and includes guidance on calculating storage volumes and supplemental landscape irrigation.

 

Florida Invests in Everglades Water Quality Projects   

The federal government is investing more than $1.4 billion in restoring the Florida Everglades. In coordination with the State of Florida, programs will focus on improving water quality and protecting habitat. One project already planned is the restoration of 1215 ha (3000 ac) of floodplain along the Kissimmee River. In addition, 24,300 ha (60,000 ac) of wetland treatment systems or stormwater management areas are currently built or in construction, and 2630 ha (6500 ac) are planned. The state will also install flow equalization basins to store and slowly release water to the wetlands.

These projects are part of a recent agreement primarily between the U.S. Environmental Protection Agency, the Florida Department of Environmental Protection, and the South Florida Water Management District to reduce and monitor phosphorus discharges into the Everglades. Read More.

 

U.S. and Brazil Promote Sustainable Urban Development With New Website 

At the Rio+20 Conference, held June 20 to 22, the U.S. and Brazil announced a new website supporting the U.S.–Brazil Joint Initiative on Urban Sustainability. The goal of the initiative and the site is to increase investments and expand markets for clean technology and sustainable urban infrastructure. Browse the site by sectors, including water quality and water management, or by keys to enhancing sustainability: policy instruments, financial mechanisms, and example projects. Currently, projects include Philadelphia’s Green City, Clean Waters program and those from Rio de Janeiro. Read more.

 

 The Role of Water Utilities in Stormwater Management 

Water is often compartmentalized into drinking water, wastewater, and stormwater. However, all three sectors have the common goal of protecting watersheds. In June, the American Water Works Association (AWWA) hosted its 2012 Annual Conference and Exposition, which included several speakers on source water protection. Speakers discussed the impacts of stormwater on water quality and the cost of drinking water treatment. Erosion can also decrease reservoir capacity due to sedimentation. In contrast, collecting rainwater can reduce stormwater pollution and decrease reliance on groundwater and other traditional supplies. Most utilities responding to a 2010 AWWA source water protection survey  have a utility policy specifically for source water protection. Read more about how water utilities can take an active role in protecting source water quality.

 

 Share Your Ingenious Stormwater Solutions 

Sometimes problem-solving with the tools at hand results in brilliant solutions. The Water Environment Federation is hosting an Ingenuity Contest for all clever ideas related to stormwater and wastewater, from treatment to management. For example, using duct tape and a shop vacuum, operators at the Village of Andes (N.Y.) Wastewater Treatment Plant designed a simple solution for managing Nocardia foaming. Winners of the Ingenuity Contest will be invited to give a 10-minute presentation in the WEFTEC® Innovation Pavilion. Submissions are due by July 13.

 

Post ItCheck It Out! 

Cigarette butts are one of the most commonly littered items, but inventor Ken Beckstead hopes to change that with his Butts Only Box®. The boxes have a unique design that makes it easy to throw butts in on the go — on roads or trails, for example. A grated opening also keeps human hands and animals out. By itself, one cigarette butt may not be a significant problem, but an estimated 770 million kg (1.7 billion lb) of cigarette butts wind up in waterbodies worldwide, according to the American Littoral Society.  Cigarettes are not biodegradable and can harbor chemicals that are toxic in high concentrations. Wildlife can also mistake butts for food.