Photo: Michael Kedzierski
Contaminated stormwater is a major source of ground water and surface water degradation. Furthermore, land development practices often create impervious surfaces that increase stormwater runoff and inhibit ground water recharge. A combination of approaches is needed to improve runoff quality and maximize quality recharge to ground water. These approaches include preventing the contamination of stormwater, minimizing impervious surfaces, segregating clean and contaminated stormwater, and applying best management practices (BMPs) that promote natural aquifer recharge and treat stormwater sufficiently before it is discharged to ground water.
Why stormwater matters to ground water...
In natural, undeveloped areas, a large percentage of relatively uncontaminated precipitation infiltrates the ground, thus recharging the ground water; the remaining runoff flows to nearby water bodies or evaporates. Natural physical, chemical, and biologic processes cleanse the water as it moves through vegetation and soil and into ground water. Development alters natural systems as vegetation and open spaces are replaced with new areas of impervious surfaces such as roads, parking lots, roofs, and turf, which greatly reduce infiltration and thus ground water recharge. Uncontrolled stormwater runoff collects pollutants such as sediments, pathogens, fertilizers/nutrients, hydrocarbons, and metals, which ultimately contaminate and degrade surface and ground water.
From the Ground Water Report to the Nation