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- Stormwater / MS4
Stormwater / MS4
What Is MS4?
Untreated or uncontrolled storm water runoff is the number one cause of impairment in our local waterways. Polluted runoff is often transported through municipal drainage systems until it eventually discharges into streams, lakes, and rivers untreated.
An MS4, or Municipal Separate Storm Sewer System, is comprised of drainage systems, including streets, catch basins, curbs, gutters, ditches, man-made channels and storm pipes, owned by a state, county, city, town, township, borough or other public entity.
The National Pollutant Discharge Elimination System (NPDES) storm water Phase II regulations require permit coverage for storm water discharges from MS4s, mainly those located in urbanized areas.
Therefore, most Townships and Boroughs are required to comply with the MS4 Program.
In summation, a MS4 makes sure that our stormwater is clean and properly managed through the implementation of 6 Minimum Control Measures (MCM).
The Minimum Control Measures Are:
MCM # 1 – Public Education and Outreach on Stormwater Impacts.
MCM # 2 – Public Involvement / Participation.
MCM # 3 – Illicit Discharge Detection and Elimination (IDD&E).
MCM # 4 – Construction Site Run Off.
MCM # 5 – Post Construction Stormwater Management (PCSM) in New and Re-Development Activities.
MCM # 6 – Pollution Prevention / Good Housekeeping for Municipal Operations.
What can you do to help?
Preventing pollution from occurring is a great first step. This can be achieved by considering all the little things you do each day that has effect on the environment and then seek ways to do them in an environmentally friendly way. Consider the following:
Car WashMany people don't realize that washing their vehicle can be a form of pollution. If you wash your car on your driveway or other impervious surface it could enter the stormwater system or local waterways. This may result in soap, scum, and oily grit polluting our waterways. To reduce the impact, wash your car on gravel, grass, or other permeable surfaces away from stormwater facilities or open waterways. Better yet, go to a local car wash. Car washes are required to filter and clean their water before it is discharged.
Pet waste can be a major source of bacteria and excess nutrients in local waters. When walking your pet, pick up the waste and dispose of it properly. Leaving pet waste on the ground increases public health risks by allowing harmful bacteria and nutrients to wash into the storm drain and eventually into local water bodies.
Excess fertilizers and pesticides applied to lawns and gardens wash off and can pollute streams. Use pesticides and fertilizers in accordance with the manufacturer's recommended amount. Never leave yard waste in the street and don't sweep it into storm drains or streams.
Construction activities can be a big source of stormwater contamination if runoff is not properly controlled. Pollutants such as sediment, debris, and chemicals could easily be picked up in stormwater runoff if you or your contractor are not careful. It is easier to protect your stormwater features and waterways than to replace, repair, or clean them if damaged due to improper site maintenance. Be sure to:
- Minimize the amount of soil you need to disturb to control erosion and create a grass buffer.
- Protect stormwater areas, open waterways, as well as vegetative areas or woodlands with silt fence or silt sock.
- Do not cross streams or enter streams with equipment unless you have obtained a stream crossing permit. Protect open waterways from construction activity with silt fence or silt sock.
- Inspect the site regularly, especially after each rain event, to ensure all control measures are operating properly.
- Silt Fence - The bottom of the silt fence must be buried and it must be attached securely to stakes.
- Silt sock must be filled with weed free compost of organic matter and installed per the specifications. It should be staked through the middle of the sock to hold it in place. Loose compost may be used on the upside of the silt sock to seal gaps between the soil surface and the sock to improve filtration and sediment retention.
- Clean up the site to eliminate debris, chemicals and other pollutants from being picked up by stormwater runoff.
- Sweep dirt off impervious surfaces regularly.
- Enter and leave the site using an appropriately stabilized entrance. Do not run through swales or a muddy access.
Keeping up with vehicle maintenance helps protect our waterways. When a vehicle leaks oil, antifreeze, brake fluid, or other liquids they lay on the surface of the road. When it rains or snow melts, the runoff picks up the pollutants and carries it into our waterways. Never dump any chemical out on the road, your driveway, or into a stormwater system. Clean up spills immediately with kitty litter or other absorbent material and sweep it up for proper disposal.
Do your part to make our waters clean for aquatic life to live in and for us to enjoy by following these quick steps:
1. Never pour any hazardous substance such as used oil, cleaning supplies, paint, or vehicle fluids outside where it could enter any part of the stormwater system or impervious surfaces. Dispose of them properly
2. Use pesticides and fertilizers sparingly to prevent excess runoff.
3. Correct vehicle leaks (dripping fluids) such as oil, grease, gasoline, antifreeze, and brake fluid.
4. When walking your pet, pick up the waste and dispose of it properly. Leaving pet waste on the ground increases public health risks by allowing harmful bacteria to wash into the storm drain and eventually into local water bodies.
5. Sweep up litter and debris from sidewalks, driveways, and parking lots to avoid having it wash into stormwater systems which could clog them or wash into waterways.
6. Inspect your stormwater system or your erosion and sediment control (if under construction) regularly to ensure it is operating properly.
- Build a Rain Barrel (PDF)
- Chester County Stormwater Authority MS4 (PDF)
- Construction Runoff (PDF)
- EPA urban-facts
- Homeowners Guide MS4 (PDF)
- Stormwater and the Construction Industry (PDF)
- Stormwater Operations and Management Pamphlet (PDF)
- Stormwater Puzzle
- Water Efficient Landscaping (PDF)