Potential Sources of Water Pollution in LaPorte County

Figure 10. Point source and nonpoint source pollution.

Potential Point Source Pollution Because point source discharges require permits, excellent information is available about potential point sources discharging in LaPorte County. Twenty-three facilities (municipal sewage treatment plants, factories, schools, packing plants, etc.) were permitted to discharge wastes in LaPorte County’s water in 1996. The largest dischargers in LaPorte County are NIPSCO in Michigan City, the Michigan City Sanitary District, LaPorte Municipal Sewage Treatment Plant, and Roll Coater in Kingsbury. They have permits to discharge substances like suspended solids, ammonia, cadmium, copper, lead, and chlorine. A limited amount of flow is allowed to by-pass the sewage treatment plants during storms.

The three Superfund sites in LaPorte County can be considered point sources of ground water contamination.

The 250-acre Fisher-Calo site near Kingsbury previously housed a U.S. military installation used to manufacture weapons. This was followed by an industrial park. Ground water was contaminated by volatile organic compounds (VOCs), and the soil contains PCBs and semi-volatiles. Extensive cleanup is taking place at the site, including the removal of about 3,500 buried drums and 4,000 surface barrels. Contaminated soil is being treated, and ground water is being pumped and treated with air stripping. The 32-acre Waste, Inc. landfill east of Michigan City accepted approximately 128,000 tons of industrial wastes from 1966-1982. The landfill was unlined, and there were no dikes to control runoff. Groundwater and soils at the site, as well as sediments in Trail Creek were contaminated. The landfill has now been closed and capped. The third Superfund site is Cam-Or in Westville where contaminated soil and groundwater are being treated. For more information contact the LaPorte County office of Emergency Planning and Hazardous Material at 326-7700 x265 or the Laporte County Health Department.

Potential Nonpoint Source
Pollution Potential nonpoint source pollution exists everywhere in the watershed. Sediment is the largest pollutant by volume in most Indiana streams. Sources of sediment include farm fields, construction sites, and streambank erosion. Although some erosion is natural, flow changes due to development (increased impervious area) may increase streambank erosion. Nutrients, such as phosphorus or nitrogen, are potential pollutants in either ground or surface water. Nutrients can come from urban or rural areas, and result from normal home and farm operations as well as accidents or spills. Major sources of nutrients include septic systems, fertilizers, and livestock manure.

Urban and Residential Nonpoint Sources
Septic systems have the potential of leaching nutrients into the ground water and can contaminate the surface water if the system is not functioning properly. According to the 1990 census, of the 42,268 households in LaPorte County, 43% use a septic system for waste disposal, while the other 57% of the housing units are connected to the public sewer system (which treats the waste and then discharges into a river or lake as a point source). No information is available on how well the 18,000 septic systems in the county are performing. Salt, oil, fertilizers for lawns, and antifreeze are other examples of urban pollutants that can be washed off from rain and enter the water system as pollutants. No figures are available on urban lawn chemicals and runoff, which may be significant sources of pollution from residential areas. Household hazardous wastes can also contaminate water if not disposed of properly.

Agricultural Nonpoint Sources
Agriculture can also contribute to nonpoint source pollution. Sediment, nutrients and pesticides can be transported by water from cropped fields and land where manure is applied. Roughly 215,000 acres or 55% of LaPorte County is used for planting crops. About 56% of cropped fields were in corn in 1994, with the remainder mainly in soybeans and small grains.

Information on fertilizer sales from the Office of the Indiana State Chemist shows that 18,974 tons of fertilizer were sold in LaPorte County in 1996. Manure from livestock may also contribute nutrients to ground and surface water. Livestock in 1994 included more than 21,000 cattle and 31,000 hogs. Large livestock facilities must be permitted by the Indiana Department of Environmental Management.

No statistics are available for pesticide use or runoff in LaPorte County. Indiana Agricultural Statistics tracks pesticide use statewide and this information could be assumed to represent LaPorte County. In Indiana in 1995, the most widely used pesticides were the herbicides atrazine, alachlor, and metolachlor. Large-scale studies carried out in Indiana and elsewhere have shown that typically about 1% of applied pesticides end up in lakes or rivers.

Many farmers are changing their practices to protect water resources. Erosion and chemical runoff from fields can often be reduced by using conservation tillage, defined as any tillage system that leaves 30 percent or more of the soil surface covered with crop residue. Conservation tillage was used on 25% of the cropland of LaPorte County in 1995. Some farmers are scouting their fields so that only necessary pesticides are applied. Many farmers test their soils to ensure that crops only receive the amount of fertilizer that is needed, and some have installed grass waterways and buffer strips to protect water quality and provide habitat for wildlife.