SEPA Uniteds States Environmentall Protection Agency EPA841-F-03-003  Water  Protecting  Quality  from  URBAN RUNOFF  Clenn Nater ls Everyledy Bwfiness  n urban and suburban areas, much The most recent National Water Quality Inventory reports that runoff  oft the land surface is covered by buildings and pavement, do not allow rain and snowmelt to soak into the ground. Instead, most developed areas rely on storm drains to carry large amounts of runoff carries pollutants such as oil, theys seriously harm water quality. Toj protect surface water quality and should be designed and built to minimize increases in runoff. How Urbanized Areas Affect Water Quality Increased Runoff Thej porous and varied terrain of natural landscapes like forests, wetlands, and grasslands traps  which  from urbanized areas is the leading source of water quality impairments tos surveyed estuaries and thet third-largest source of impairments to Did you know tbat because ofimpervious surfaces like pave-  surveyed lakes.  runoff from roofs and paved areas to ment and rooftops, a typical city block generates more than nearby waterways. The stormwater 5 times more runoffthan a woodland. area ofthe same size? directly to streams and rivers, where surface, where it runs off rapidly in urbanization may also cause profound  dirt, chemicals, and lawn fertilizers and snowmelt remains above the groundwater resources, development Storm sewer systems concentrate  The loss ofinfiltration from groundwater changes. Although urbanization leads to greati increases inf fooding during and immediately after wet weather, ini many instances during dry weather. Many native fish and other aquatic life cannot survive Increased Pollutant Loads and amount of pollutants carried pollutants include: Sediment Oil, grease, and toxic chemicals from motor vehicles Pesticides and nutrients from lawns and gardens Viruses, bacteria, and nutrients from pet waste and failing septic systems Road salts Heavy metals from roofs shingles, motor vehicles, and other sources Thermal pollution from dark: impervious surfaces such as streets and rooftops These pollutants can harm fish and wildlife populations, kill native vegetation, foul drinking water unsafe and unpleasant.  unnaturally large amounts. runoffinto smooth, straight and erosional power as it travels underground. When this runoff into a stream, its excessive volume and power blast out streambanks, wiping out aquatic habitat. These  conduits. This runoff gathers speed it results inl lowers stream flows leaves the storm drains and empties when these conditions  prevail.  damaging streamside vegetationand Urbanization increases the variety increased storm flows carry sediment into streams, rivers, and lakes. The  rainwater and snowmelt and allows loads from construction sites and them to filter slowly into the ground. other denuded surfaces and eroded In contrast, impervious (nonporous) streambanks. They often carry surfaces like roads, parking lots, and higher water temperatures from rooftops prevent rain ands snowmelt streets, rooft tops, and parking] lots, fromi infiltrating, or soaking, into- which are harmful to the health and  the ground. Most oft the rainfall 40% evapotranspiration  reproduction of aquatic life.  30% evapotranspiration  10% runoff  55% frunoff  25% shallow infiltration Natural Ground Cover  10% shallow infiltration  25% deep infiltration  5% deep  infiltration supplies, and make recreational areas  75%-100% Impervious Cover  Relationship between impervious cover ands surface runoff Impervious cover ina a watershedi results ini increased surface rumoff As little as 10 percent impervious coveri ina a watersbedcanz resulti ins stream degradation.    Managing Urban Runoff What Homeowners Can Do To decrease polluted runofffrom paved surfaces, households can develop alternatives to: areas traditionally covered byi impervious surfaces. Porous pavement materials are available for driveways and  and pumped every 3 to 5 years. Theys should and water quality). Urban planners and also practice water conservation measures to others responsible for managing urban Controlling Impacts from New and examine source control opportunities.  extend the life oftheir septic systems.  and suburban areas can first identify and implement pollution prevention strategies They should seek out priority pollutant reduction opportunities, then protect natural areas that help control runoff, and finally begin ecological restoration and retrofit activities to clean up degraded water bodies. Local governments are encouraged marking, pollution prevention outreach campaigns, and partnerships with citizen groups and businesses. Citizens can help tol become involved in restoration efforts, and mark storm drains with dump" messages.  Development Developers and city planners should attempt to control the volume ofrunoff  sidewalks, and native vegetation and mulch from new development by using low can replace high maintenance grass lawns. impact development, structural controls, Homeowners can use fertilizers sparingly and pollution prevention strategies. Low ofyard waste, they can use the materials to hydrologic areas like riparian buffers and start a compost pile. And homeowners can infiltrable soils); reduce development learn to use. Integrated Pest Management impacts; and reduce site runoff rates by polluted runoffb by picking up after pets and Controlling Impacts from using, storing, and disposing of chemicals Existing Development  and sweep driveways, sidewalks, and roads impact development includes measures that tot take lead: roles inj public education instead of using a hose. Instead of disposing conserve natural areas (particularly sensitive efforts through public signage, storm drain  (IPM) to reduce dependence on harmful In addition, households can prevent properly. Drivers should check their cars for leaks and recycle their motor oil and antifreeze when these fluids are changed. Drivers can also avoid impacts from car  maximizing surface roughness, infiltration prioritize the clean-up strategies, volunteer  pesticides.  opportunities, and flow paths.  "don't approved  Controlling runofff from existing urban areas is often more costly than controlling runoff from new developments. Economic efficiencies are often realized through  wash runoff (e.g., detergents, grime, etc.) by approaches that target "hot spots" of using car wash facilities that do not generate runoff! pollution or have multiple benefits, runoff. Households served by septic systems such as high-efficiency street sweeping should have them profesionalyinspected (which addresses aesthetics, road safety,  Related Publications www.epa.gov/nps  Turn Yourl Homei into a Stormwater Pollution Solution! This web site links to an. EPA homeowner's guide tol healthy habits for clean water that provides tips for better vehicle and garage care, lawn and garden techniques, home improvement, pet National Management Measures to Control Nonpoint Source  Low Impact) Development Center ibwipaminepmasting  This center provides information on protecting the environment and water resources through integrated site design techniques that are intended to replicate preexisting hydrologic site conditions. Stormwater. Manager's Resource Center (SMRC) Created and maintained by the Center for Watershed Protection, this resource center is designed specifically for stormwater Strategies: Community Responses tol RunoffPollution nwantcogwatetpalaronftomaonkap Thel Natural Resources Defense Council developed this inter- active web document to explore some oft the most effective strategies that communities are using around the nation to control urban runoff pollution. The document is also available in print form and as an interactive CD-ROM.  care, and more.  www.stormwatercenter.net.  Pollution from Urban Areas PMCpne  This technical guidance and reference document is useful tol local, practitioners, local government officials, and others that need state, and tribal managers in implementing management programs technical assistance on stormwater management issues.  for polluted runoff. Containsi information on the best available, economically achievable means ofreducing pollution ofsurface waters and groundwater from urban areas. Onsite Wastewaterleatment System Resources wwwepgpvfowm/onsie This web site contains the latest brochures and other resources from EPA: for managing onsite wastewater treatment systems (OWTS) such as conventional septic systems and alternative decentralized systems. These resources provide basic information tol helpi individual homeowners, as well as detailed, up-to-date technical guidance ofinterest tol local and state health  Forl More Information U.S. Environmental Protection. Agency Nonpoint Source Control Branch (4503T) 12001 Pennsylvania. Avenue, NW Washington, DC: 20460 www.epa.gov/nps  departments.