Leaving no stone unturned, or more accurately no significant stormwater source uncontrolled, American Rivers, the Natural Resources Defense Council and Clean Air Council petitioned the U.S. Environmental Protection Agency (EPA) to ensure control of significant sources of pollution that contribute to costly local clean-up efforts and are not already adequately addressed by urban stormwater programs.
In the Delaware River basin, stormwater runoff is the most common clean water problem—storms wash nutrients from exposed soils, erode streambanks, and carry pollutants of off hard surfaces such as rooftops and roadways. There is a strong correlation between these impervious or hard surfaces and degraded water quality in our streams.
Where there are large areas of imperviousness, cities bear the cost of treating drinking water and cleaning streams that flow to downstream communities. Yet cities do not have the ability to control some of the most significant polluted stormwater runoff at its source when it is generated on private property. Controlling polluted stormwater runoff on the site of private commercial, industrial and institutional facilities with large areas of impervious surface will greatly reduce pollution in streams and the burden of clean up for localities.
Take a look at the small watershed of Army Creek in New Castle County, Delaware, just south of the city of Wilmington. The watershed is less than 8,000 acres and flows directly into the Delaware River. It serves an urban residential population and much commercial and industrial activity. This creek, as its name implies, is a workhorse. Notable clean ups of pollutants such as dioxin and PCBs from past activities have already occurred to help this creek continue its service and maintain healthy flows to support the diverse Delaware River estuary habitat. But, Army Creek is also on the state’s list of impaired waterways because of excess nutrients or nitrogen and phosphorus pollution. Nearly 32% of the watershed’s land area is commercial, industrial or institutional and 80% of that land use is within half a mile of Army Creek. Models estimate that, out of all urban stormwater sources, these land uses in Army Creek’s watershed contribute 34% of total phosphorus pollution and 39% of total nitrogen pollution. The large swaths of hard, impervious surfaces associated with these commercial, industrial and institutional land uses likely contribute four times the nutrient pollution loads that Army Creek watershed would receive under natural land cover from the entire watershed.
In the Army Creek watershed, in watersheds throughout EPA Region 3 and across the nation, these significant contributors of polluted stormwater runoff to impaired waterways represent a gap in stormwater management programs and a costly clean-up burden to localities receiving polluted runoff to their stormwater infrastructure system. These polluting sources fall outside of existing controls such as 1) Delaware’s urban stormwater permit (or MS4) for which New Castle County is the permit holder and permit requirements are limited to permit holder controlled land, 2) management practice requirements for control of runoff at new development or redevelopment sites that do not apply to existing development and 3) control of typical point source pollutants such as the PCBs and dioxins or those treated as wastewater and then discharged directly into the Delaware River. Fortunately, EPA can help…
The Clean Water Act has a provision called residual designation authority (RDA). If EPA determines that a sector or category of stormwater discharge sources are contributing to water quality violations, the agency must exercise its authority—RDA– and require those polluters to have permits which will direct steps toward pollution reduction.
We have petitioned EPA to use RDA to require contributors of stormwater runoff to work under a permit to manage their stormwater and ensure Army Creek can deliver clean water to the Delaware River. Since green infrastructure practices such as green roofs, rain gardens and porous pavement offer sustainable and cost-effective ways manage stormwater from large areas of imperviousness, RDA can also drive benefits within Army Creek such as safer communities, cleaner air, flood damage reductions and more attractive industrial, commercial and institutional sites. Saleem Chapman, Director of Policy and Strategy at Clean Air Council says “experience developing green infrastructure solutions in Delaware demonstrates the advantages of these types of clean water projects to overall local community health.”
Our petitions ask EPA to use RDA so significant sources of stormwater pollution will no longer be unpermitted, uncontrolled, burdening localities and impairing waterways. RDA can help reduce polluted stormwater reaching Army Creek within New Castle County and other urban watersheds and communities throughout EPA Region 3.
- Read the Army Creek petition for EPA Region 3 to exercise RDA [PDF]
- Read the petition for Back Creek within the Chesapeake Bay [PDF]
- Read about petitions in EPA Region 9, California