Nonpoint Source Issues
Sources of Nonpoint Source Pollution
Other Major Issues
COMMON WATER QUALITY ISSUES
NONPOINT SOURCE ISSUES
A significant and resistant water quality issue is nonpoint source pollution. Nonpoint source pollution results from "land runoff, precipitation, atmospheric deposition, drainage, or seepage." Rainfall, snowmelt, or irrigation runs over land or through the ground, picks up pollutants, and deposits them into rivers, lakes, and coastal waters or introduces them into ground water.14 Nonpoint sources can be defined as water pollution sources that do not fit the definition of point sources in the Clean Water Act (section 502(14)):
The term "point source" means any discernible, confined, and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. This term does not include agricultural storm water discharges and return flows from irrigated agriculture.
A draft definition for "nonpoint source water pollution" has also been offered by the Nonpoint Source Task Force created in 1996 to update Indiana's Nonpoint Source Pollution Management Plan. That definition would provide: "Nonpoint source water pollution is water pollution originating from diffuse, nondiscrete sources that are not regulated as point sources by the Clean Water Act's National Pollutant discharge Elimination System (NPDES) program. Nonpoint source water pollution generally results from land runoff, percolation, atmospheric deposition, hydrologic modification, or precipitation."15
Identifying nonpoint source pollution as runoff can create confusion. Some runoff is eventually discharged from conveyances identified as point sources, such as storm sewers. This discharge is regulated by the Clean Water Act requirements under the National Pollutant Discharge Elimination System permitting program. In general, nonpoint sources (including some diffuse point sources) are believed responsible for between one-third and two-thirds of existing and threatened impairments of state waters.16 The particular challenge of reducing this type of pollution is that it is so widespread, does not originate from a single source, or discharges into a waterway at a particular site.
Sources of Nonpoint Source Pollution
Potential sources of nonpoint source pollution include activities which disturb the land or water. Examples are agriculture, forestry, grazing, septic systems, recreational boating, urban runoff, construction, physical changes to stream channels, and habitat destruction.17 The State of Indiana Nonpoint Source Pollution Management Plan identifies nonpoint source pollutants that should be reduced in Indiana. A report completed by Purdue University in 1992 indicates that municipalities and developed areas are the primary sources of nonpoint pollution in the Grand Calumet River drainage basin.18 An estimate of the costs to control these contaminants from reaching the river is $855 million with an additional $102 million to maintain the control works.19
Another major contributor to nonpoint source pollution in Indiana is eroded soil. The eroded soil can increase turbidity and sedimentation which is detrimental to aquatic life in and commercial use of the waterways. Toxic contaminants can adhere to sediments resulting in harm to aquatic life.20
Nitrogen resulting from the handling of fertilizers is a serious problem when its levels are more than what is considered healthy in drinking water for humans, domestic animals, or wildlife. Although sewage treatment plants and public water supplies have reduced the risk of contracting diseases, animal waste can still contaminate surface and ground water with pathogens. Animal and vegetable waste in waterways can also deplete the oxygen supply in the streams necessary for aquatic life. Chemical pollutants associated with agricultural and home use such as pesticides and herbicides can also have harmful affects on aquatic life.
Urban areas contribute to diffuse runoff when activities occur such as precipitation and runoff, land development, and turf management. Precipitation in urban areas often results in increased runoff due to the impervious surfaces of developed areas. Natural percolation and adsorption capabilities are reduced. Precipitation can also increase loads to combined sewer overflow systems. Land development involves disturbance of soil which results in high rates of erosion. Soil loss has its greatest impact in downstream areas where sedimentation occurs. Turf management for areas such as golf courses, sod farms, and lawns can contribute high amounts of pesticides and fertilizers to the surface and ground waters.21
The disposal of wastes, both solid and liquid, occurs generally through a land disposal method. Some methods of disposal of sludge from septic systems, municipal and industrial wastewater treatment facilities, household garbage, and other debris contribute to the nonpoint pollution dilemma. These methods include land application of sludge and wastewater, on-site sewage disposal, and septic disposal.
Landfills not only involve soil disturbance which can be washed into waterways, but wastes can seep from the landfill as leachate. Other disposal methods that pose similar issues include municipal sludge lagoons and closed landfills or abandoned waste disposal sites.
The production and storage of hazardous waste is a potential source of contamination. The accidental or intentional spill or discharge of unpermitted substances is also considered a source of nonpoint source pollution.
Flood control and drainage activities often involve earth moving or excavation. Soil erosion and stream bank erosion are two potential results of these activities. Stream channelization, dredging, dam constriction stream bank modification, channel relocation, and road and bridge construction require mechanical equipment that can remove vegetation, allow mechanical fluids to be dispersed, and chemicals to restore vegetation.
Agricultural practices involve several related activities that contribute to nonpoint sources of pollution. In Indiana, more than 13 million acres of cropland are cultivated, and erosion from the cropland can lead to sedimentation. Along with the soil that is eroded, fertilizer and pesticide chemicals may also be washed into nearby waterways. Animal waste runoff from confined feeding operations and grasslands can be another source of nonpoint source pollution, as well as the land application of animal waste.
Atmospheric deposition has been identified as another major source of nonpoint pollution. Air emissions can be transported hundreds of miles before falling to the earth's surface or bodies of water. Once on the earth's surface, precipitation can carry these contaminants to receiving waters. Pollutants can also fall directly into surface waters. Estimates by the Environmental Protection Agency indicate that up to 70% of the PCB load to Lake Michigan is due to atmospheric deposition.
The Canadian National Pollutant Release Inventory and the U.S. Toxics Release Inventory state that 73% of total releases from manufacturing in the Great Lakes basin were emitted to the air. This figure increases to 85% when manufacturing emissions within the "one-day airshed" are included (the one-day airshed is approximately the eight Great Lakes states, Ontario, western Quebec, Vermont, and most of West Virginia). The amount would increase also if emissions from electric power utilities and municipal incinerators were reflected in these total loading figures. The dilemma is that the relative contributions of these deposition sources are not well understood.22
The U.S. Geological Survey has been conducting air deposition research through a grant from the Indiana Department of Environmental Management. The research is focused upon the nonpoint source pollution in northern Lake County. Initial findings from this on-going air deposition monitoring project are found in Quality of Wet Deposition in the Grand Calumet River Watershed, Northwest Indiana (June 30, 1992 - August 31, 1993).23
Recreational boating can impact surface water quality. Increased wave action can induce shoreline erosion resulting in higher rates of sedimentation. Motor boat activity can resuspend sediments, releasing contaminants throughout the water column. Marinas are located on shorelines for boat storage and access, however, the activities conducted at marinas can introduce pollutants such as oil and grease, gasoline, and other products used for boat maintenance which are then washed into the water. The paved surfaces for vehicle parking and dry storage of boats can increase the amount of runoff.
Road salt, sodium chloride and calcium chloride, are used to maintain safe roads, highways, and parking lots under icy conditions during winter months. Cyanide compounds are often added to reduce clumping. The runoff from the paved surfaces carrying the chloride and cyanide compounds can result in surface and ground water contamination. The storage of these materials is also an issue of concern for water quality.24
The Indiana Department of Transportation is developing technology which promotes the measured use of salt on Indiana highways. The technology includes computer evaluation of needs based upon changing highway conditions as identified by Department of Transportation trucks in the field. The goal is to provide highway transportation safety and snow maintenance in a manner which is economical and sensitive to the environment. An informational seminar was held in October 1995, in which the Department of Transportation, the Department of Environmental Management, Purdue University Department of Civil Engineering, and the U.S. Geological Survey discussed "Safe and Sane Road Salting" and outlined their cooperative efforts to reach this goal.
In addition to salt, the Department of Environmental Management will address the water quality impacts of heavy metals, oils and greases, and suspended solids. Temperature sensors have already been placed along the Indiana Toll Road in Lake County to help monitor salt needs. Toll Road trucks are calibrated by computer to help assure that salt placement is effective without being excessive.25 In April 1998, the Indiana Department of Transportation (INDOT) and the Department of Environmental Management announced their plans to build a wet detention pond and wetlands to catch runoff from the Toll Road's Buchanan/Grant Street interchange in Gary. INDOT will provide $230,000 for the project. An EPA grant in the amount of $129,000 will also be applied toward the project. Design work for the project is to be conducted by Purdue University.26
A 1992 study in north Lake County estimated 19% of the lead, 15% of the copper, 10% of the chemicals that use oxygen in the water, and 9% of the suspended solids in the Grand Calumet River come from runoff from the area's roadways. The roadways only comprise 2% of the watershed's total area. The detention ponds and wetlands will catch 90% of the runoff and allow the contaminants to settle. The water from the pond will eventually drain to the Grand Calumet River and the sediments will be removed periodically.27 OTHER MAJOR ISSUES
A common water quality issue is the discharge of effluent through "combined sewer overflow systems." A combined sewer system is a wastewater collection system that is designed, constructed, and operated to carry both sanitary sewage and storm water runoff to a publicly owned treatment plant. During dry weather conditions, diversion structures carry these waters to the treatment plant. During wet weather events, however, flows often exceed the capacity of the wastewater treatment facility, sewer system, and diversion devices, resulting in a combination of sewage and storm water discharge to the surface waters though the outfalls of combined sewer overflows.28 A significant contribution to the complexity of the issue is the associated infrastructure of combined sewers. Elimination or replacement of the systems can be very costly.
Similar concerns arise with respect to the functioning of septic systems. A critical factor to the design of a functional septic system is soil type. Most soils present some limitations to septic system functioning, but these limitations can often be overcome with proper septic system design. If a subdivision is developed without properly considering soil limitations on sewage disposal, lots may prove too small to accommodate a house, garage, driveway, well, and a properly-functioning septic system.29 Concerns for the use of septic systems may be heightened where those systems depend upon the use of drywells. A "drywell" is a concrete tank, perforated on the sides and bottom. Spillover from a septic drains directly into the shallow drywell, from which effluent seeps readily into the surrounding material. Water-supply aquifers can become polluted through seepage from drywells.30
Applying a grant under Section 319 of the Clean Water Act, the Indiana Geological Survey recently concluded a project involving the detailed monitoring of hydrologic and chemical conditions in the immediate vicinity of drywells at Beverly Shores. The Indiana State Department of Health and the Indiana Department of Environmental Management also participated in the project. Over a three-year period of intensive monitoring, the Indiana Geological Survey documented the percolation of septic effluent to the shallow water table at two local residences. Although pore waters in the unsaturated sand below the drywells were rather contaminated (high nitrate levels and abundant bacteria), the water in the zone of saturation was still generally of good quality. The study indicated that while the chemical quality of the water-table aquifer (the residential water source) is still good, contaminated effluent is invading the aquifer. The study suggested that long-term or increased usage of drywells in highly permeable dune sands "should be discouraged."31
Persistent toxic substances are a common water quality concern. In fish and wildlife, reproductive failures, deformities, and physiological malfunctions is associated through strong evidence to the presence of various pesticides, PCBs, dioxins, furans, and similar substances. "Persistent toxic substances" is defined by the Great Lakes Water Quality Agreement as: "Chemicals that can cause death, disease, behavioral abnormalities, cancer, genetic mutations, physiological or reproductive or physical deformities in any living species or its offspring. Also, those chemicals that can become poisonous after concentration in the food chain or in combination with other substances, and which have a half-life in water of more than eight weeks." The sources of these substances often are not localized. The effects of persistent toxic substances are on local and global environments due to atmospheric and other methods of transport.32
New evidence continues to reinforce that harm to humans from persistent toxic substances is similar to that caused in wildlife. Research indicates that several aspects of male reproductive health has declined over the past 30 to 50 years. Just as disorders seen today originated 20 to 40 years ago, the influences on male reproductive health in babies today may not become apparent for decades. Other effects involve the endocrine-endocrine response system, and behavioral and cognitive problems in school children.33
Thermal pollution is also a matter of some concern. Forms of heat pollution affecting ground or surface water include discharges from hydroelectric operations, coolant waters for industrial uses, and open loop geothermal heat pump systems. Hydroelectric operation discharges must obtain a permit through the NPDES program administered by the Indiana Department of Environmental Management. Water used to cool machinery is also regulated by the NPDES permitting program if cooling waters are discharged to surface waters. If the water is injected into an aquifer by an injection well, a Class V Injection Well Permit may be required from the Environmental Protection Agency pursuant to the Safe Drinking Water Act discussed later in this chapter.34 According to James Bose of the International Ground Source Heat Pump Association, open loop systems typically raise or lower water temperature less than 10 Fahrenheit, and the temperature change is rapidly dissipated upon discharge.35
Urban landscapes often have warmer temperatures than the surrounding rural countryside. The phenomenon is known as the "Urban Heat Island" and was first identified by Meteorologist Luke Howard in 1818. At first, Urban Heat Islands were studied by medical doctors because of the implication to health. Later, scientists were able to distinguish the environmental factor that caused warmer temperatures in urban areas. Principally, the factors that effect the Urban Heat Island are artificial surfaces including streets, sidewalks parking lots, and buildings. These features typically cover up to 30% of the land in cities. Concrete and asphalt . . . tend to absorb much of the solar radiation it receives. Consequently, energy is re-released into the atmosphere at night. Additional heat is created from mechanical, electrical, and chemical energy generated in the city.36 Urban Heat Islands can contribute to increases in smog. The photochemical reactions causing smog become intensified in higher temperatures. Higher temperatures also tend to lead to an increase in the consumption of energy resulting in more fossil fuels being burned by power plants, subsequently, additional smog causing pollutants are then emitted to the air.37