Groups piping up about threat of many small drains to water quality
Studies reveal amount of sewage discharged into streams may be much greater than thought
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Some solutions for restoring the Chesapeake Bay and its rivers arrive by way of high-tech, scientific processes. Others begin by pulling on boots.
Over the last 18 months, the Center for Watershed Protection studied several urban Maryland streams to investigate pollution flowing into them from storm drains.
The center worked with local water management agencies and nonprofit watershed groups to look closely at Sligo Creek in Montgomery County, and Western Run, Moores Branch, and a small part of the Jones Falls in Baltimore City and Baltimore County.
The research hinged on a task that cash-strapped public agencies can rarely afford: inspecting the entire length of the streams on foot.
Supported by grants from the National Fish and Wildlife Foundation, Rauch Foundation and the EPA, researchers walked the streams and conducted water quality tests at the ends of open pipes.
Their findings suggest that relatively small pipes releasing untreated sewage into streams may collectively be sending more nutrients to Bay tributaries than previously suspected.
Nutrients, primarily nitrogen and phosphorus, are the major cause of degraded water quality in the Bay.
"In many cities and counties, these pipes represent a leading source of bacteria and nutrients entering our waterways, yet the pervasiveness and severity of the problem are largely unknown or misunderstood," said Center for Watershed Protection executive director Hye Yeong Kwon.
Federal permits for stormwater drainage systems require local governments to monitor water quality at the open ends of pipes, called outfalls. But while a large city can have thousands of outfalls, regulations focus on pipes that are 36 inches or larger. Even then, only a sampling of the larger pipes is typically monitored during a permit cycle.
The federal regulations were designed to monitor pollution from industry. Tests for ammonia or E. coli - which indicate raw sewage and related pollution from nutrients and bacteria - are not required.
"People don't realize how outdated their methods are, from not testing for fecal material to not looking at pipes less than 36 inches," Kwon said.
As a result, communities may be overlooking a significant source of pollution to local streams and missing a cost-effective option for cleaning up their waters.
In some cases, field teams with the Center for Watershed Protection found far more outfall pipes than were identified on maps. Approximately 41 percent of all pipes surveyed measured less than 36 inches in diameter, which means they would most likely be overlooked by existing monitoring programs.
And while stormwater pipes flush especially large loads of pollution into streams during wet weather, many of the pipes surveyed had flows during dry weather, too. Polluted dry weather flows indicate persistent problems in addition to those triggered by stormwater. In these studies, 70â€“80 percent of the dry weather flows were polluted.
Many of the dry weather flows from smaller pipes carried a range of contaminants like oil, detergent, fluoride and ammonia. Approximately 80 percent carried raw sewage.
Polluted flows from outfall pipes are called illicit discharges.
The source of an illicit discharge may or may not be illegal. They originate from a range of problems that include illegal dumping, broken sewer lines seeping into stormwater and the deliberate or accidental connections of sewer lines to the stormwater system.
Kwon said the center's findings are a red flag for communities that need to reduce nutrient loads to the Bay.
"There is strong evidence that illicit discharges are a huge part of the pollution problem in the Chesapeake Bay and in other parts of the country," Kwon said. "Regulators, advocates and local governments should encourage the elimination of illicit discharges as a first step to clean our local waters rather than make a foregone conclusion that the issue has been addressed simply because a program requirement has been checked off."
Richard Batiuk, associate director for science with the EPA Chesapeake Bay Program, said that the center's findings could help explain questions about nutrients in urban streams. Scientists project the amount of nutrient pollution that should be found in a stream based on surrounding land use, but the actual amount of nutrients found in urban streams is often higher than expected.
"Land use tells us one thing, but the streams tell us another," Batiuk said. "Something doesn't match."
The unrecognized, cumulative impact of so many small polluted outflows could explain the difference.
Finding and correcting illicit discharges - especially those that involve sewage - could make a big difference in water quality. Such repairs could be critical for municipalities throughout the Bay region, which are struggling to meet federal requirements for reducing nutrient pollution in local waters. Reductions in bacteria could also make water safer for human contact.
David Flores, restoration manager for the nonprofit group Blue Water Baltimore, has helped with several efforts to locate and test more stormwater outfall pipes in Baltimore.
Flores said that persistently polluted dry weather outfalls, along with the contaminated stew that arrives through surges of stormwater, are collectively killing urban streams.
"There are 'hot' outfalls everywhere, and the Center for Watershed Protection study confirms it," Flores said. "Our greatest opportunity to improve water quality in Baltimore is to tackle this issue."
Researchers at the Center for Watershed Protection believe that removing illicit discharges has great potential for advancing water quality goals in the EPA's "pollution diet" for the Chesapeake Bay.
They estimated the benefits by combining their stream study findings with existing data on nutrient pollution for the larger watersheds. Based on calculations for Western Run and the Jones Falls, the aggressive removal of illicit discharges could achieve 43 percent of the local nitrogen reduction goal and 21 percent of the local phosphorus reduction goal. For Sligo Creek and the Anacostia, widespread removals could achieve 17 percent of the local nitrogen reduction goal and 6 percent of the local phosphorus reduction goal.
Eliminating illicit discharges could also save money. In densely developed areas, Kwon said that repairing stormwater pipes can cost much less than redesigning surface areas to retain and absorb large volumes of stormwater.
Kwon points to an example in which a 10-mile stream had 30 outfalls with sewage-related nutrients in dry weather flow. The discharges were small but persistent. Over the course of the year, these 30 outfalls deliver the same amount of nitrogen as stormwater runoff from 560 acres of impervious surface and the same amount of phosphorus as stormwater runoff from 140 acres of impervious surface.
The center estimated a total repair cost for that section at approximately $300,000, based on $10,000 for each of the 30 outfalls. In comparison, the cost for stormwater retrofits to achieve the same amount of nutrient reductions could top $50 million. Comparisons that raise repair costs to $50,000 for each outfall still result in significant savings.
Although the Center for Watershed Protection specializes in helping communities with stormwater retrofit projects, Kwon said that finding and correcting illicit discharges is an important part of the package.
"We don't want to discount the importance of green infrastructure, but we're missing an opportunity here," Kwon said.
The center is working with a number of communities on better methods to track and repair illicit discharges. Partners in the Chesapeake region include Baltimore City, Montgomery County, Cambridge, Salisbury, Cumberland, St. Mary's County, and Richmond. They are emphasizing the need for complete inventories of outfalls, as well as testing for the presence of untreated sewage.
Resource managers say that finding and fixing illicit discharges remains a challenge. In urban settings, the number of outfall pipes is simply daunting. Both federal permits and limited funds require resource managers to tackle larger pipes first.
"We don't monitor all of the outfalls. We just don't have the resources," said Kim Burgess, chief of surface water management for the Baltimore city Department of Public Works.
A "311" call system helps citizens report overflows and discharges, and the city works to correct problems. When they can't respond in the field, the number and location of problems helps to pinpoint areas that need more attention.
Baltimore is also beginning a long, hard search for illegal connections between sewage pipes and storm drains.
"We are trying to clean up a problem that's taken a hundred years to make," Burgess said. "It means a lot that the federal government is putting infrastructure as a priority, but lots of people think only in terms of street structures. As citizens and voters, we can ask for more focus on these pipes, and we haven't done that yet."
Baltimore County is required to monitor 150 outfalls each year. The focus has been on the larger pipes, but natural resources manager Steve Stewart said the county is also working to screen about 2,700 smaller outfalls over time. The county receives about 10,000 calls each year from citizens reporting problems at outfalls.
"We're never satisfied with the coverage we have," Stewart said, "but we could triple or quadruple the size of my section and still focus almost exclusively on illicit connections. We're not convinced that's the best way to spend our resources."
Illicit discharges that occur because of infrastructure problems usually involve sewage and pose their own sets of problems. Other discharges, like petroleum or detergents, are sudden and temporary. Even if they recur over time, possibly from illegal dumping, such discharges often have no witnesses and end too quickly to track.
Mike Smith, a volunteer with Friends of Sligo Creek, and Pat Ratkowski, a volunteer with the Audubon Naturalist Society, were working along Brashears Run when a gush of sudsy of water spewed from a large outfall pipe behind him. Smith used his cell phone to report the discharge to the county as it was happening.
In 10 minutes, the flow had stopped. Globs of white settled over water that was already an unnatural shade of green. But by the time county personnel attempted to trace the source upstream, the suds had dissolved and washed downstream. The trail had gone cold.
Identifying consistent problems and tracking down the source will always be a challenge, but the rewards might be worth it.
According to the Center for Watershed Protection, progress begins with two steps: mapping and testing.
Watershed ecologist Lori Lilly said that local governments should check the accuracy of their outfall maps and include pipes of all sizes.
"Mapping is a big investment in the beginning, but in the long run it will help you," Lilly said.
Local government agencies should also routinely test the water at outfalls for ammonia. This simple water quality test indicates the presence of sewage and can help assess nutrient loads to the stream.
Neither of these tasks is required under the federal stormwater permit. Lilly would like to see this change.
In the meantime, volunteer help is needed.
"Volunteers with watershed groups can help with the mapping and the monitoring, and use this methodology to find illicit discharges in the field," Lilly said. "They also have a role in advocacy. Sometimes government bureaucracy can get in the way of fixing problems, and these groups can come in and help push things along."
The need to meet local and regional cleanup goals in cost-effective ways may also encourage progress with illicit discharges. The Bay Program's Batiuk agreed that mapping and quantifying the problem is a critical first step to receiving credit toward Chesapeake Bay nutrient reduction goals for the work.
"To get credit, municipalities need to have some accounting for the discharge so that we know it's there and coming from a defined source," Batiuk said. "This is a real source, and we want to provide credit for the work they're doing."
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