Chesapeake Quarterly Volume 7, Number 2: Urban Stormwater and the Bay
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Urban Stormwater and the Bay

By Erica Goldman

urban area in Baltimore - photo by Skip Brown
cows in a pasture - ourtesy of the National Resources Conservation Service
Urban issues like stormwater receive less attention than agriculture in the context of Baywide restoration efforts. With limited dollars and big problems, many argue that focusing an agriculture will bring more bang for the buck when it comes to reducing nurient loads to this troubled estuary. But with the combined pressues of suburban development and aging infrastructure, Baywide goals to reduce of nitrogen, phosphorus, and sediment in urban areas are losing ground. Left photograph by Skip Brown and right photograph courtesy of the National Resources Conservation Service.

Stormwater from city streets ends up in the Chesapeake Bay, carrying heavy metals, organic carbon, nitrogen, and phosphorus to the mix. But among the expensive problems facing the troubled estuary, where does urban stormwater fit in?

This is not easy to answer, says Tom Simpson, who's served for 10 years as chair of the Nutrient Subcommittee of EPA's Chesapeake Bay Program. The subcommittee's Urban Stormwater Work Group devotes most of its energies right now to planning for stormwater management in new development, he explains, not on retrofitting older systems.

To him, this allocation of effort within the Bay Program makes sense. New development offers an opportunity to get it right the first time when it comes to stormwater infrastructure. "The dumbest thing we can do is to keep creating new problems when we can't solve existing ones," Simpson says.

Cost and Benefit

But existing stormwater infrastructure, especially in older urban areas, clearly needs to be upgraded to protect local waters as well as tidal waters downstream. And the Bay Program has a mandate to address large-scale urban stormwater problems, explains Simpson. Maryland's Tributary Strategy, in fact, requires a retrofit of 40 percent of all stormwater infrastructure in developed land by 2010.

"Frankly, the 40 percent was not something that anyone ever felt was achievable," says Simpson. He says that this high number came as a concession to bring other practices, like agriculture, to higher levels. "It's the piece we'll never get to."

According to calculations, retrofitting 40 percent of existing stormwater infrastructure would reduce nutrient loadings by 5 to 10 percent — at a cost of $7 to $8 billion. By comparison, changes in agricultural practices and sewage treatment plant upgrades could cut nutrient loads by 80 percent — at price tag of $2 to $3 billion. "If the priority is nutrient reduction in the Chesapeake Bay, urban stormwater is not the wisest expenditure," he says. Targeting agriculture would bring the greatest impact, he says, which "leaves the urban side out in the cold in terms of retrofitting."

There is a disconnect between local stormwater issues and Baywide restoration goals, says Simpson. "We keep trying to portray our need for good stormwater management under the auspices of trying to restore the Chesapeake Bay. Maybe that isn't why we should do it. We need to build a case on local merits of needs for stormwater [management]."

Local governments are well aware of the merits of managing stormwater. Right now, the responsibility for managing stormwater falls squarely on their shoulders, thanks to regulatory requirements from the National Pollution Discharge Elimination System (NPDES). "We want to do our part to protect Bay and tidal tributaries, but we have significant problems within local streams," says Meosotis Curtis, who administers the stormwater permitting system for Montgomery County's Department of Environmental Protection. Local governments need money to meet those requirements, she says, but they are getting little financial assistance from watershedwide efforts like the Bay Program.

Permits and Pollution

The NPDES permitting process for stormwater, created in 1972 by the Clean Water Act, requires municipal separate storm sewer systems (MS4s), like Watershed 263, to develop stormwater management programs that prevent harmful pollutants from being washed into the system and then discharged into local waters.

Currently MS4 permits are more "programmatic" than regulatory. Counties must monitor water quality of stormwater, work to reduce discharges of compounds (such as nitrogen, phosphorus, and total suspended solids), and provide outreach and education.

An MS4 permit says that whatever you are doing must improve water quality, explains Curtis. It is basically a mandate to "do good things." The current language does not set any limits for how much nitrogen and phosphorus, for example, can be present in stormwater. But future permits may set "load limits" for stormwater runoff.

Such so-called "load limits" already apply to the permitting process for industries, power plants, and sewage treatment plants. These daily limits, or Total Maximum Daily Loads (TMDLs), were originally established by the Clean Water Act to protect local waters from cumulative pollutant loads from a range of potential sources. Both Simpson and Curtis say that these TMDLs would also set more stringent requirements for the quality of stormwater runoff. With such a change, stormwater outfall pipes, like sewage treatment plants, would not be allowed to discharge nutrients or sediment above a certain fixed amount. In some instances, these load limits already exist, says Curtis. In the Anacostia, for example, load limits have been established for sediment, coliform bacteria, and biological oxygen demand (a proxy for the metabolic activity of bacteria). Tougher regulations will soon be coming nationwide, Curtis says, and these will act as a big "regulatory hammer" for stormwater management.

New load limits for stormwater may produce positive ripple effects in other environmental areas — such as air pollution. "If we have to actually remove nitrogen from stormwater, we don't have a lot of tricks," says Simpson, so prevention is key. Since much of the nitrogen loading in stormwater comes from airborne exhaust from cars and power plants that drifts down to road surfaces, urban areas may have to push for more stringent air pollution controls. "The best BMP [Best Management Practice] is for it [nitrogen oxides, etc.] not to fall," he says.

Finding Funds

With load limits required by MS4 permits, it would be easier to make the case for funding stormwater management — at both local and federal levels. When the Clean Water Act was first passed, the federal government provided money for municipal wastewater upgrades. If load limits are imposed on stormwater, says Curtis, "we would hope that funding would come from higher levels. It will cost a huge amount of money."

Some good news for funding urban stormwater projects came this year when the state legislature created the new Chesapeake Bay Trust Fund, seeded at $25 million for the first year. Within the Trust Fund will be the Chesapeake Bay Nonpoint Source Fund to provide financial help for urban and suburban stormwater management.

So is urban stormwater a local or Baywide issue? The answer appears to be that it is both. "To build a case for stormwater, urban stormwater can't be about the Bay," says Curtis. It's about the quality of life in the urban environment, she says.

Simpson agrees. "If you've got people feeling good and connected to local waters, he says, "just as the waters connect to the Bay, they will connect too."

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