Point source vs.
nonpoint source water pollution

Shifting struggles for clean water

We are water creatures. The human body is 70 percent water, and about 75 tons of water passes through each person during a lifetime. So it behooves us to take care of this miraculous liquid. Life depends on pure water. But water doesn't want to stay pure. It wants to mix and wash. It wants to cleanse the world, carry away all the chemical residues of industrial society.

So we have a never-ending struggle to keep water clean, and to clean up the water which we have allowed to be sullied. In the past 25 years of environmental regulation, we have made great progress in some outstanding cases, such as the cleanup of Lake Erie and the Cuyahoga River. The irony, however, is that while some of the formerly most polluted areas are dramatically cleaner today, many of our most pristine streams are being degraded. As suburbia sprawls over the countryside, increased stormwater runoff is polluting the upper reaches of our watersheds. In the future, we may have no more than mediocre water quality throughout the region.

Point sources

Prior to the 1970s, a lion's share of water pollution in Northeast Ohio was caused by industry. Factories and mills used rivers to carry away their untreated process waters. They drew water to cool their machines and then returned it, heated and contaminated. Rainwater fell on mountains of stockpiled industrial materials and carried contaminated soil from industrial yards. The transportation of raw materials and finished products caused spills, which further contaminated the water.

In the 1970s federal environmental legislation began to control wastewater effluent through the issuance of discharge permits. The Ohio Environmental Protection Agency, the agency responsible for issuing these discharge permits (called National Pollution Discharge Elimination System, or NPDES permits) to every Ohio industry and sanitary sewage plant, has been working to bring all the dischargers into compliance with the law and to improve the permitting system itself. As a result of the regulatory oversight, major capital investments by industries and municipalities and significantly improved operation and management systems, there have been dramatic decreases in the pounds of pollutants discharged to surface water in the region.

Today the permit system is by no means perfect. Ohio EPA continues to look for illegal dischargers and adapt regulations to the large number and varied nature of the permitted dischargers. Since 1985 there have been approximately 175 permitted dischargers in the Cuyahoga River watershed alone. Roughly two-thirds of these permits were issued to industries. The remaining third were issued to sanitary sewage plants. These sources of pollution are known as "point sources" because their waste comes to the river at one point through a discharge pipe. Their treated wastewater, even after applying the best available technology, can contribute measurable levels of metals and conventional pollutants.

Nonpoint sources

Nonpoint sources of pollution have not received as much attention as the industrial dischargers and sanitary sewage plants, although they contribute more of certain contaminants than point sources. Nonpoint source pollution originates where some use of the landwhether farming, feedlots, oil and gas wells, storage tanks, landfills, industrial stock piles, streets, construction and development, urban cores and suburban housing (to name a few)has resulted in the disturbance of earth and/or contamination. The contamination is washed from the area by rainfall, often attached to soil particles that may be eroding from the area, and carried to waterways in stormwater runoff. In such runoff one can find virtually anything that can be found in industrial and sanitary sewage plant waste streams and more, including PCBs and pesticides.

Active use of the land, such as construction, can accelerate erosion and sediment loading to a river. Sediment is destructive for several reasons. It covers river bottoms, destroying habitat for fish and other aquatic organisms. Lighter sediment particles remain suspended, cause a muddy appearance in the water, and prevent light from getting through to the life on the river bottom. And sediment often carries chemical contaminants.

Atmospheric deposition is a nonpoint source that impacts Lake Erie. Fallout of air pollution directly to the water's surface contributes over half the cadmium and benzo-a-pyrene to the lake, in addition to smaller loads of other metals and organic pollutants. Atmospheric deposition may be impacting local rivers as well.

Hazardous waste sites are in a third key nonpoint source category. These sites are locations of past or abandoned industrial activities, spills or waste storage where toxic contamination is likely to exist. In the Cuyahoga River watershed, for example, there are approximately 200 known sites and possibly more which have not been identified. The release of pollutants from these local sites is largely unknown. However, in other areas of the Great Lakes and the nation, hazardous waste sites have been known to release contaminants which have then polluted the environment and been linked to health problems.

Urban stormwater runoff can carry measurable levels of metals, bacteria, PCBs, oil and grease, and trash. A study done in the early 1980s concluded that older cities like Akron and Cleveland contributed more pollutants than newer cities. Much of the pollution that is carried in urban runoff was once air borne, but oil from leaky cars and trucks, contamination and debris from abandoned or old industrial yards, sediment from highly traveled, unvegetated open space or abused stream banks, feces from urban animals also end up as water pollution. Stormwater runoff from suburban areas can become contaminated in the same way. Additionally, suburban areas can contribute high levels of nutrients where homeowners improperly apply fertilizers to their lawns. In both urban and suburban areas, road salt runs off into the water, creating toxic conditions for the aquatic life. The disposal of used motor oil, antifreeze, paint thinners, etc., down storm drains further contaminates the water.

Combined sewer overflows (CSOs), sanitary sewer overflows and wastewater treatment plant bypasses are a third source category of water pollution. Combined sewers carry wastewater from homes, businesses and industries along with stormwater to the sanitary sewage treatment plants (such combined pipes are common in older urban areas). During a heavy rainfall, stormwater runoff can cause a dramatic increase in the water flowing through the combined sewers. Special control devices on the combined sewers allow some of the combined wastewater to overflow into streams and rivers so that the pipes don't back up into homes or businesses. Urban sewer districts in Northeast Ohio are currently studying how much CSOs contribute to water quality problems and how to reduce the overflows.

Portions adapted from the Cuyahoga River Remedial Action Plan Stage 1 Report Public Review Summary.


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