Stormwater - Pollution
What is "Illicit Discharge?"
Federal regulations define an illicit discharge as "...any discharge to a storm sewer that is not composed entirely of stormwater." Sources of illicit discharge include sanitary wastewater, effluent from septic tanks, car wash wastewaters, improper oil disposal, laundry wastewater, spills from roadway accidents, and improper disposal of auto and household toxins.
Illicit discharges enter the system through either direct connections (such as wastewater piping either mistakenly or deliberately connected to the storm drains) or indirect connections (such as infiltration into the sewers from cracked sanitary systems, spills collected by drain outlets, or paint or used oil dumped directly into a drain.)
Effects of Illicit Discharge:
- The result is untreated discharges that contribute to high levels of pollutants, including heavy metals, toxins, oil and grease, solvents, nutrients, viruses, and bacteria to receiving waterbodies. These receiving waterbodies most often contain the water we drink, cook with, swim and bathe in. This in turn costs us more money for water treatment.
- Pollutant levels from these illicit discharges have been shown in EPA studies to be high enough to significantly degrade receiving water quality and threaten aquatic life, wildlife, and human health.
How Illicit Discharges can be Prevented:
- Dispose of wastewater properly down sanitary sewer drains
- Make sure septic tanks are properly functioning
- Dispose of vehicle fluid waste at proper locations (many auto parts stores accept used motor oil and other auto fluids for recycling or disposal)
- Properly dispose of paints (contact your trash hauler for specific questions)
Effects of Pollution:
Polluted stormwater runoff can have many adverse effects on fish, animals, plants and people. Polluted stormwater often affects drinking water sources. This, in turn, can affect human health and increase drinking water treatment costs to astronomical levels.
- Sediment can cloud the water and make it difficult or impossible for aquatic plants to grow. Sediment can also destroy aquatic habitats and make it difficult or impossible for fish to breath.
- Excess nutrients can cause algae blooms. When algae die, they sink to the bottom and decompose in a process that removes oxygen from the water. Fish and other aquatic organisms can't exist in water with low dissolved oxygen levels.
- Bacteria and other pathogens can wash into swimming areas and create health hazards, often making beach closures necessary.
- Debris such as plastic bags, plastic six-pack rings, bottles, and cigarette butts can choke, suffocate, or disable aquatic life like ducks, fish, turtles and birds when washed into bodies of water.
- Household hazardous wastes like insecticides, pesticides, paint, solvents, used motor oil and other auto fluids can poison aquatic life. Land animals and people can become sick from eating diseased fish and shellfish or from ingesting polluted water.
Residential - To prevent pollution, recycle or properly dispose of household products that contain chemicals, such as insecticides, pesticides, paint, solvents, used motor oil, and other auto fluids. Don't pour them onto the ground or into storm drains or gutters.
In winter, we often turn to salt to melt the snow and ice. Salt, however, adversely impacts the environment, especially our streams. Excess salt can saturate and destroy the soils' natural structure and result in more erosion to our waterways. A high concentration of salt can damage and kill vegetation. Salt poses the greatest danger to fresh water ecosystems and fish. Excess salt can seep into groundwater and stormwater runoff. Effective ice control can help prevent excess salt runoff to our waterways. Because all deicers can be harmful to the environment when applied in excess, the best strategy is to reduce the use of these chemicals as much as possible.
Below are some rules to follow:
- Shovel sidewalks and pathways to keep them clear and to prevent ice from forming. Remember, salt and deicers are not effective when more than three inches of snow have accumulated.
- Consider the temperature. Salt is less effective when the temperature is below 25 degrees Fahrenheit.
- Only use deicers when a storm is about to come through.
- Reduce use of deicers by adding sand or small stones for traction.
- Apply the least amount of deicer or salt to get the job done.
Septic Systems - Leaking or poorly maintained septic systems release nutrients and pathogens (bacteria and viruses) to the surface or into groundwater that can be picked up by stormwater and discharged into nearby water bodies. Pathogens can cause public health problems and environmental concerns.
Auto Care - Washing your car and degreasing auto parts at home may save some money, but can send detergents and other contaminants through the storm sewer system. Dumping automotive fluids into storm drains has the same result as dumping the materials directly into a water body.
- Use a commercial car wash that treats or recycles its wastewater, or wash your car on your lawn so the water infiltrates into the ground.
- Repair leaks and dispose of used auto fluids properly.
Pet Waste - Pet waste can be a major source of bacteria and excess nutrients in local waters.
- Remember to pick up pet 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.
Lawn Care/Landscaping - Excess fertilizers and pesticides applied to lawns and gardens wash off and pollute streams, rivers, and lakes. Yard clippings and leaves can also wash into storm drains and contribute nutrients and organic matter to water bodies as well.
There are four methods of landscaping that help with stormwater management:
- Permeable Pavement - Traditional concrete and asphalt don't allow water to soak into the ground. Instead, these surfaces rely on storm drains to divert unwanted water. Permeable pavement systems allow rain and snowmelt to soak through, decreasing stormwater runoff.
- Rain Barrels - You can collect rainwater from rooftops in mosquito-proof containers. The water can then be used later to water lawn or garden areas.
- Rain Gardens and Grassy Swales - Specially designed areas planted with native plants can provide natural places for rainwater to collect and soak into the ground. Rain from rooftop areas or paved areas can be diverted into these areas rather than into storm drains.
- Vegetated Filter Strips - Filter strips are areas of native grass or plants created along roadways or streams. They trap the pollutants stormwater picks up as it flows across driveways and streets.
Maintaining Grass Drainage Swales - A grass drainage swale is an open channel that collects water from hard surfaces and allows it to percolate slowly into the ground. Swales can help to increase water filtration, decrease water flow velocity, prevent erosion and direct runoff during storms into other stormwater facilities or into the storm drain system. The following is a list of ways to maintain your swale:
- Inspect your swale after storms, check that water has drained and that there is no erosion
- Remove sediment and debris from in and around the swale to prevent blockage of water flows
- Mow fescues and bluegrass no shorter than 2.5 to 3 inches, remove tall clippings
- Manually remove weeds or invasive plants
- Remove leaves in the fall, as they may smother grass and block the flow of water
- Adjust the mower height to avoid scalping the edges of the side slopes
- As Needed-
- Reseed any bare areas
- Contact DEP if you continue to have problems
- Never use fertilizers or pesticides in the swale
- Never over-mow, or mow shorter than 2.5 to 3 inches
- Never mow immediately after rain
Information for this page has been obtained from the Pennsylvania Department of Environmental Protection, the Center for Watershed Protection, the Cornell University Cooperative, and the Environmental Protection Agency.