Pollutants of Concern

Stormwater and snow-melt runoff in a parking lot

Storm water runoff from impervious surfaces carries large amounts of various pollutants to the surface waters of the United States. These pollutants include nutrients, silt/sediment, pathogens, oil/grease, metals, debris and litter. Of particular concern to the water bodies in the Syracuse Urbanized Area (SUA), are phosphorus and sediment.

Phosphorus (and other nutrients)

An algea bloom caused by nutrient loading

Phosphorus is the nutrient of greatest concern because it promotes weed and algae growth in lakes and streams. Excessive weed growth clogs waterways and blocks sunlight. 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. Some sources of nutrients are fertilizer, excrement and detergents.

Silt and Sediment

Large amounts of silt and sediment, when dislodged and swept by storm water into water bodies, can disrupt ecosystems in a number of ways. Storm water runoff that contains sediment can deposit harmful amounts of silt in sensitive areas such as wetlands, wildlife preserves, and stream and lake bottoms harming habitat needed by aquatic insects and plants. Sediment blocks sunlight needed by aquatic plants to grow. Sediments can carry toxic chemicals that cause the oxygen in water to be used up. Sediment generally is the result of soil erosion from lawns, hillsides and gardening/landscaping activities.

Toxic Substances (gasoline, household products and paint thinner)

Toxic substances may enter surface waters either dissolved in runoff or attached to sediment or organic materials. The principal concerns in surface water are their entry into the food chain, bioaccumulation, toxic effect on fish, wildlife and microorganisms, habitat degradation, and potential degradation of public water supply sources. Some toxic substances that may be present in residential areas, businesses and construction sites are listed below:

Residential: Pet waste, vehicle fluids (oil, gas and antifreeze) paint, pesticides, solvents, batteries, hazardous wastes, street litter, soap from car washing and swimming pool discharges.
Businesses: Fuel, soap from equipment washing, waste process water and hazardous liquids.
Construction: Sediment, wash water from concrete mixers, used oil and solvents, vehicle fuels and pesticides.

Pathogens (bacteria, viruses)

Contaminated water resulting from stormwater runoff

Bacteria and viruses include infectious agents and disease producing organisms normally associated with human and animal wastes, leakage from sewers and seepage from septic tanks. These organisms can cause disease in humans and animals when present in drinking water and contact recreation water bodies. Biological contaminants come from litter, organic matter and animal waste.

Oxygen-demanding Organics (human and animal excreta; decaying plant, animal matter; discarded litter, food wastes)

Oxygen demanding organics such as human and animal excreta, decaying plant, animal matter; discarded litter, and food wastes

Organic materials (natural or synthetic) may enter surface waters dissolved, or suspended, in runoff. Natural decomposition of these materials may deplete dissolved oxygen supplies in the surface waters. Dissolved oxygen (DO) may be reduced below the threshold necessary to maintain aquatic life, impairing or killing fish and other aquatic plant and animals.

Metals (lead, mercury, copper and cadmium)

Metals in water can be toxic to humans, aquatic life and other animals that drink water. Metals come from vehicle exhaust, weathered paint, metal plating, tires and motor oil.

Oil and Grease (petroleum products)

Oil and grease may be toxic to aquatic life, even in small amounts. Oil and grease in storm drains can generally be traced to automotive leaks and spills or improper disposal of used oil and automotive products into storm drains.

Thermal Stress (sunlight)

Direct exposure of sunlight to urban streams which lack shade may elevate stream temperatures, which can exceed fish tolerance limits, reduce survival and lower resistance to disease. Urban street surfaces and other impervious surface areas which have been heated by sunlight may transport thermal energy to a stream during a storm event adding stress to biota. Cold water fish (such as trout) may be eliminated, or the habitat may become marginally supportive of the fishery.

Floatables (litter)

Floating litter in water may be contaminated with toxic chemicals and bacteria, are unattractive to look at, and can cause death to aquatic animals and birds. Commonly observed floatables include cigarette butts, plastic containers, wrappers and cans. Floatables are generally the result of careless handling or littering.