The City of McMinnville is one of more than 85 Tennessee communities that has submitted a Notice of Intent (NOI) application to the Tennessee Department of Environment and Conservation (TDEC) for coverage under the Tennessee phase II MS4 general storm water permit.
Under this permit, McMinnville has developed a program to manage the quality of storm water runoff from the storm water drainage system. The program will focus on the following:
What is stormwater runoff?
Stormwater runoff is the water that flows off roofs, driveways, parking lots, streets, and other hard surfaces during rain storms. Rather than being absorbed into the ground, it pours into ditches, culverts, catch basins, and storm sewers. It does not receive any treatment before eventually entering the community’s streams and lakes.
What problems does it cause?
Stormwater can carry harmful nonpoint source pollutants, cause flooding, erode topsoil and stream banks, and destroy marine life habitats. In an area with natural ground cover, only 10% of rainwater becomes runoff. The rest is absorbed or evaporates. In urban areas, up to 55% of rainfall can become storm water runoff.
Why are the storm water and sewer systems separate?
Unlike waste water, which is treated before it is released back into the environment, storm water goes directly into a community’s ponds, streams and lakes. Because stormwater comes in large amounts at unpredictable times, treating it as waste water would be very expensive.
What is nonpoint source pollution?
Nonpoint source pollution is water pollution that is difficult to trace to a specific discharge point. Because it comes from many diverse sources, it is hard to control. Examples of common nonpoint source pollutants include fertilizers, pesticides, sediments, oils, salts, trace metals, and litter. They come from farms, yards, roofs, construction sites, automobiles, and streets.
What is impervious surface area?
Any surface that does not readily absorb water and impedes the natural infiltration of water into the soil. Common examples include roofs, driveways, parking areas, sidewalks, patios, decks, tennis courts, concrete or asphalt streets, crushed stone and gravel surfaces.
How does the city determine impervious surface area?
For single family homes, a statistical sampling is taken using Geographical Information System (GIS) including aerial survey data. Each is measured and an average impervious surface area is determined. For businesses and other institutions, the city measures the impervious area using aerial survey data.
What can I do to reduce pollution in stormwater runoff?
Creating natural areas on your property can help reduce the quantity of stormwater runoff. Disposing of wastes properly, using the minimum amount of chemicals on your yard, and keeping your car well-maintained can reduce the amount of pollution that you add to storm water runoff.
ADDITIONAL THINGS WE CAN DO TO HELP
- Report any non-emergency type pollution problem to your local government offices. For emergency pollution problems, such as major spills, call 911.
- Never dump anything down a storm drain inlet. They flow directly to our lakes and streams.
- Keep your leaves and grass clippings out of the streets so that they do not end up washing into the storm drain inlets.
- Wash your vehicles on your lawn or at a car wash facility instead of in your driveway.
- Keep your automobiles and your gas powered lawn mowers or blowers well tuned so that they are not dripping toxic fluids or emitting toxic fumes.
- Do not use chemicals on your lawn before it is expected to rain, and try using organic or slow-release products, which are better for your lawn and for the environment.
- Be conservative with pesticides and herbicides (weed killers) and try natural alternatives. Call your local Extension Service to find out more about natural pesticides.
- Make sure your air conditioners are in good working order and not leaking harmful chemicals.
- Install early closing toilet flappers and water conserving shower heads.
- Lawns need less than an inch of water per week. If it rains an inch, do not water. Try using a rain gauge.
*** TO REPORT ILLICIT DISCHARGES INTO STORM SEWER SYSTEMS ***
CONSTRUCTION STORMWATER DOCUMENTS
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