Pollutants associated with nonpoint sources

Nonpoint sources and pollutants associated with them. (Source:Adapted from [The Stormwater Pollution Prevention Handbook], Conservation Toronto and Region, 2001)

<width=70%>Pollution sources	<width=30%>Pollutants of concerna
Vehiclular traffic accounts for much of the build-up of contaminants on road surfaces and parking lots. Wear from tires, brake and clutch linings, engine oil and lubricant drippings, combustion products and corrosion, all account for build-up of sediment particles, metals, and oils and grease. Wear on road and parking surfaces also provides sediment and petroleum derivatives from asphalt. Spills from traffic accidents can occur on any street or highway.	Heavy metals (lead, zinc, copper, cadmium, mercury) hydrocarbons (oil and grease, gasoline, cleaning solvents) Salt (sodium, chloride) Sediment
Lawn and garden maintenance of all types of land uses including residential, industrial, institutional, parks, and road and utility right-of-ways accounts for additions of organic material from grass clippings, garden litter and fallen leaves. Fertilizers, herbicides and pesticides all can contribute to pollutant loads in runoff if not properly applied.	Phosphorus Nitrogen Fertilizers and pesticides Organic debris Oxygen demand
Air pollution fallout of suspended solids from traffic, industrial sources and wind erosion of soils builds up contaminants in soil and on urban surfaces.	Organic pollutants (polycyclic aromatic hydrocarbons (PAHs) Pesticides Polychlorinated biphenyls (PCBs) Phenols Heavy metals Nitrogen and sulfur oxides Hydrocarbons Mercury
Municipal maintenance activities including road repair and general maintenance (road surface treatment, salting, dust control, etc.).	Sediment Hydrocarbons Salt
Industrial and commercial activities can lead to contamination of runoff from loading and unloading areas, raw material and by-product storage, vehicle maintenance and spills.	Any raw material exposed to runoff
Illicit connections of sanitary services, roof/sump drains or industrial process water to storm sewers can cause contamination with organic wastes, nutrients, heavy metals and bacteria.	Bacteria and viruses Phosphorus Nitrogen Excess water Heavy metals
Improper disposal of household hazardous wastes can introduce waste oil and a multitude of toxic materials such as paint, solvents, auto fluids, and waste products to storm and sanitary sewers. Note that industrial and commercial hazardous materials are regulated under point source control programs.	Any household material deemed hazardous
Pet and wildlife feces and litter introduce organic contamination, nutrients and bacteria.	Bacteria and viruses Phosphorus Nitrogen
Construction activity can introduce heavy loads of sediment from direct runoff, construction vehicles and wind-eroded sediment. Sediment particles also: transport other pollutants that are attached to their surfaces including nutrients, trace metals and hydrocarbons; fills ditches and small streams and clogs storm sewers and pipes, causing flooding and property damage; and reduces the capacity of wetlands, reservoirs and lakes. Construction can also contribute construction debris, material spills and sanitary waste.	Sediment Phosphorus Nitrogen Debris Sanitary waste
Combined sewer overflowsb (CSOs) and Sanitary Sewer Overflows (SSOs) contain a mixture of sanitary, commercial and often industrial waste, along with surface drainage.	Bacteria and viruses Phosphorus Nitrogen Suspended solids heavy metals Organic contaminants Oxygen demanding substances
Runoff from residential driveways and parking areas can contain driveway sealants, oil, salt, and car care products.	Salts PAHs Hydrocarbons Increased temperature

^aRepresentative list only; many additional pollutants can be associated with most of the activities listed
^bCombined sewers are very limited in Minnesota, with only a few remnants still existing in the metropolitan area. However, the same concerns apply for sewage spills and accidental overflows.