Herald and Review from Decatur, Illinois • Page 30

Ui 1 re M1 -TVater 23. 1981 Sangamon River Basin COUNTY COUNTY LINE COUNTY SEAT DOUGLAS SCOTT I MORGAN jSANCAMOfc'r'cf ft WwiTRIE Quality problems plague Lake Decatur, river and won't dissipate," Mayhugh says. However, trihelamethane levels in the lake "don't even approach" safety standards set by the federal government, he adds. The city is required to notify residents if levels of turbidity, nitrates or bacteriological agents exceed standards. These warnings do not include boil orders, which can be issued in the event of a main break, low pressure or other temporary causes.

The city also tests the concentrations of heavy metals in the lake on a yearly basis. Mrs. Sefton says EPA tests show no abnormal amounts of metals other than copper, approximately 10 micrograms per liter over the safety level. "But that's typical of this area and is a natural level," she says. Mrs.

Sefton also says industry both in Decatur and on the river north of the city appears to have had a minimal effect on the quality of Lake Decatur. What seems to have had the greatest effect is the river, particularly the sedi-ment it carries, and the seepage of farm chemicals. Those problems are being addressed by the state and federal governments in developing studies and the Illinois water management plan. However, the future of some of the programs is in limbo right now because of federal budget cuts. And some critics charge those problems have existed for several years and are getting worse instead of better.

Ellen Allan, a writer active in area environmental concerns and a long-time Herald Review columnist, says the problems with lake quality could be seen and smelled a long time ago. She says an "anti-regulation" mood in the country and the nature of a state bureaucracy will hamper the EPA in improving the lake. She also points to'the strength of farmers in resisting changes or reductions in the use of farm chemicals. "There's a feeling the EPA is not going to move in," she says. "But there's going to be a day of reckoning." use of Illinois lakes," according to Mrs.

Sefton's 1978 report. "It was rated as a (problem) for approximately 39 percent of the lakes particularly for those in the Illinois, Mississippi and Sangamon River basins." Not only does sediment decrease the capacity of the lake to hold water, but it can kill lake life and absorb pesticides and other pollutants. Occasionally high nitrate levels, which in the spring can climb above the safety standards of 10 parts per million. The levels build from nitrogen-based farm fertilizers, which enter the river system by seeping through the ground after application and by running directly into the water through erosion, Mrs. Sefton says.

Turbidity, meaning that particles in the water block off light, making the lake appear muddy. Turbidity is a form of sedimentation and can cause similar problems for lake life. Algae and dissolved oxygen deficiencies, part of the eutrophic condition. Both affect fish life and can create a nuisance for recreation. Oxygen depletion can kill fish and allow the release of toxic substances contained in sediment.

These problems are not unique to Decatur, and it took some time for them to develop. Erosion began contributing to the decline in water quality everywhere around the turn of the century, as farmers began tilling land more, Mrs. Sefton says. The lake, created in 1922, was helped by the formation of the Soil Conservation Service in the 1930s. The service brought help and ideas to farmers and the government But by the 1970s, more acreage was in continuous corn and soybean planting, and more marginal land was brought into use.

This again led to increases in sedimentation, nitrate levels, oxygen deficiencies and turbidity. The EPA is testing Lake Decatur and 56 others on a biennial basis in preparation for development of a water management plan. The agency hopes to offer technical assistance to municipalities, who will be By LORI MILLER NmM A Review Staff Writer Old Man River rolls slowly along the western edge of Illinois, bringing history and commerce along with it A hundred miles or so to the east, the old man's adolescent counterpart, the Sangamon River, travels too, bringing with it sediment and a host of interesting chemicals and organisms. At one point, the river takes a brief yawn, the pause that otherwise is known as Lake Decatur. Between time and the river, the lake has become "very much a reflection of the Sangamon," says Donna Sefton, lakes program coordinator for the Illinois Environmental Protection Agency.

According to studies by the EPA and other state agencies, the quality of the lake does not reflect well on the river. Sampling done in 1980 shows Lake Decatur falls in the worst one-quarter of all lakes in the state in terms of water quality. Another EPA report, drawn up by Mrs. Sefton in 1978, shows Decatur ranking with some 100 other lakes as being in "poor condition and having high potential for exhibiting problems with eutrophica-tion andor sediment pollution." "Eutrophication" means the water promotes the growth of algae and other organisms which eventually can choke off a lake. And still another EPA report on the clean-lakes strategy for the state classifies Decatur in the lowest grade: poor condition with high problem potential.

Not a good report card. But Mrs. Sefton says it is not unusual for lakes in this area. For example, those lists also include Taylorville, Oakland, Paris, Carlinville, Meredosia and Sparta, among many others. And Springfield ranks in the lower half in the state.

Only the newer lakes, such as Clinton Lake in DeWitt County, escape negative comment, she says. In general, quality problems which affect Lake Decatur are: Sediment, considered by the EPA as the most serious problem "impairing the facing more and more serious water shortages and quality problems in the future. June and August were this year's test periods, but results of several of the samples will not be available until 1982, since analysis is slow, she says. However, the lake has been tested by the U.S. EPA, the state Water Survey and the state EPA at different times since 1973.

"The data has not changed much since then," Mrs. Sefton says. "There are some greater transparency problems, mainly due to the sediment coming in." Testing is also done on a daily basis by the city Water Department, says the department's James Mayhugh. Among aspects tested are nitrate levels, turbidity, bacteriological concentrations related to sewage, chlorine levels, hardness, sludge and fluoride. All but nitrates, which are 'tested weekly by both the EPA and Water Department, are checked daily.

In addition, controls are run on chemicals added, in the treatment process to ensure the measurements are correct. The city also is required to test for trihelamethane, which can interact with chlorine to form a possibly carcinogenic agent. The substance is carried by herbicides and pesticides and "can't be removed.