Municipal Separate Storm Sewer System (MS4)/Storm Water

What is Storm water?

Storm water runoff is part of the natural hydrologic process and occurs when rainwater that does not infiltrate into the ground flows into water bodies such as creeks, lakes, streams, or rivers. In suburban areas, the storm water runoff often has the benefit of passing through naturally vegetated areas, which slows down the velocity of the water and ultimately filters it for pollutants and sediments. In urban settings, however, natural vegetation and topography have frequently been altered to prevent storm water from naturally soaking into the ground and so it is most often carried by storm drains.

When the drainage pattern of a watershed is altered with the addition of impervious surfaces such as driveways, parking lots, and buildings, flows increase in concentration and velocity and pick up sediments and pollutants from land surfaces at an increased rate. Storm water that flows through urbanized areas to receiving waters is called "urban storm water runoff” or “urban runoff."

The City of Frankfort has developed a storm water program that manages the pollutants and impacts from urban storm water runoff.  The program includes education, storm water quality and quantity measures, and a storm water utility.

Pollutants

Urban runoff is known to carry a wide range of pollutants including:

• Heavy metals
• Nutrients
• Pathogens
• Petroleum hydrocarbons
• Sediments