A major contributor to contamination of our waterways is polluted surface water runoff that results from a rainstorm. This water is generally referred to as storm water runoff. Pollution from a variety of sources degrades storm water runoff as it enters the city’s streams making them unsafe for drinking, fishing, swimming, and other activities. Storm water flows over land into ditches, streams or storm sewers all of which eventually reach Accotink Creek and the Chesapeake Bay. Storm water can pick up oils, litter, sediments, fertilizers, pesticides, herbicides, and pathogens as its travels across roads, buildings, lawns, and parking lots. These pollutants enter the city’s streams and creeks where they can have very harmful effects on the water quality of the city’s streams and the streams downstream of the city.
The City of Fairfax is dedicated to educating the public about the harmful impacts of polluted storm water runoff so that the citizens can become partners with the city to restore and protect our streams. Storm water runoff is produced every time rain or snow is not absorbed directly into the soil. When land is paved the storm water can no longer infiltrate into the ground where it can be naturally filtered by the earth’s soil. Based on area studies, it is known that a significant amount of water pollution going into the Chesapeake Bay is a result of storm water discharges that are collectively called "nonpoint" sources.
One of the latest trends in the control of nonpoint source runoff for developing sites is called Low Impact Development (LID). LID was developed in the 1990’s as a method to mitigate the impacts from the increases in storm water runoff that generally result from typical land development practices. When buildings and parking lots are constructed, the imperviousness of the land is significantly reduced so that water can no longer infiltrate into the ground. The goal of LID focuses on how to develop an area to minimize the hydrologic impacts created when you reduce the imperviousness of the area so that the site better mimics a natural watershed. LID attempts to combine site planning, land development, and storm water management with ecosystem protection. LID is an excellent tool to help control non-point source pollution and their impacts to community’s streams. LID is most effective in areas where development is just starting. However, LID is a useful tool and can provide benefit to urban areas in helping to reduce the imperviousness of the land. Several design manuals currently exist for homeowners, planners, engineers, and landscape architects who wish to implement LID techniques. For more information, visit www.epa.gov