When It Rains, It Drains An overview of Stormwater Management

Stormwater Runoff Water falls as rain, snow, or ice Most water seeps into the ground If the ground is saturated, frozen, or has an impermeable surface, water flows as runoff

Point vs. Non-Point Source

Point source: – Travels through a conveyance system – Regulated under permit program Non-point source: – Runoff that comes from a wide unspecific area – Addressed through voluntary programs

Why is stormwater a problem? Human activities cause stormwater to decrease in quality and increase in quantity Caused by developed and disturbed land

Where does stormwater go? Travels over land Carried through Municipal Separate Storm Sewer Systems (MS4) Discharges into various creeks and streams Ultimately, the creeks and streams discharge into a larger body of water, like the Schuylkill River

Where does stormwater go? Stormwater flows to storm drains along the street Water may carry pollutants with it This runoff goes to streams, rivers, lakes, and the oceans untreated

Southeastern PA Watersheds DARBY CREEK WATERSHED Conestoga

Stormwater Pollutants Sediment Oil and grease Heat (thermal pollution) Nutrients Bacteria Trace metals Toxic chemicals

Sediment Pollution Sediment comes from soil erosion and from decomposition of plants and animals Sediment makes water cloudy Sediment is the most common type of water pollutant

Sediment Pollution Prevention Create vegetative buffers along bodies of water Minimize the amount of exposed soil Use silt fences when disturbing soil

Oil and Grease Pollution The EPA estimates that 200 million gallons of oil are improperly disposed of each year 1 quart of oil can contaminate 1 million gallons of water

Oil and Grease Pollution Prevention Fix vehicles that are leaking fluid If you change your own oil, store it in a container and dispose of properly

Septic System Pollution The EPA estimates that 25% of homes in the U.S. use septic systems Over 4 billions gallons of wastewater per day is dispersed below ground through septic systems

Septic System Pollution Prevention Have septic system pumped regularly Fix a faulty septic system Fix faulty toilets and leaky faucets to reduce water going through the system Don’t overload the septic system (ex: do several loads of laundry over several days, rather than all in one day)

Lawn Chemical Pollution Lawn chemicals are fertilizers, herbicides, and insecticides Over-application can cause toxic levels of chemicals and excessive nutrient runoff

Lawn Chemical Pollution Prevention Conduct a soil test Don’t over-fertilize Use chemicals according to their instructions Landscape with native plants

Thermal Pollution Rain or snowmelt running over pavement picks up heat from asphalt and concrete Warm runoff raises the temperature of bodies of water

Best Management Practices (BMPs)

Non-Structural BMPs Pollution prevention and source control Street sweeping Stormwater collection system cleaning and maintenance Low-impact development and land-use planning Snow and snowmelt management Public education

Structural BMPs Green roofs High density residential areas Grassed/porous pavement

Hillside Elementary

Rain Gardens

Rain Impoundment Basin

Benefits of Stormwater Management Enhanced opportunities for recreation Reduced flood damage Improved drinking water quality Navigational benefits Reduced illness Enhanced aesthetic value