THE BATTLE WITH POLLUTION

THE FIGHT to save Illinois waterways from the blight of pollution showed marked success during the year ending June 30, according to new water quality data released by the Illinois Environmental Protection Agency.

Dramatic increases in helpful dissolved oxygen and comparable decreases in harmful fecal coliform occurred in fiscal year 1972, the report indicated. Fiscal year 1972 covers the time span from July 1, 1971 to June 30, 1972.

For the first time every river basin in Illinois bettered Pollution Control Board standards for dissolved oxygen average for a fiscal year. The amount of dissolved oxygen is an indicator of the water's ability to support acquatic life.

Of the 17 basins that had dissolved oxygen data recorded for fiscal 1971, 10 showed fiscal 1972 increases in the chemical, while only five decreases and two remained the same.

Fecal coliform, bacteria which originate in the intestinal tracts of warm-blooded animals, usually appear in waters as a result of sewage treatment plant discharges, combined sewer overflows, and feedlot runoff.

Decreases in fecal coliform density were recorded in 164 stations as compared to increases at only 106. Seven stations showed no change, and 336 had no fiscal year 1971 data for comparision.

The Kankakee River showed the greatest reduction in the bacteria.

Substantial deterioration of the Ohio River and the Lake Michigan tributaries (Waukegan River and Pettibone Creek) was noted, however, with a large increase in the density of fecal coliform. The Lake Michigan tributaries are small streams that feed the lake.

Nevertheless, both shore water and open water of Lake Michigan bettered strict state standards by a wide margin.

The DuPage River and the Sanitary and Ship Canal on the DesPlaines River showed the greatest increases in dissolved oxygen during fiscal 1972.

Averages of all tests taken from the Sanitary and Ship Canal now meet the Pollution Control Board standard of not less than 6.0 milligrams per liter at any time. It was the only sub-basin below the standard in fiscal year 1971.

Obviously, even though the average of all tests taken on a river may meet standards, there may be individual locations which vary widely from the average.

In addition to compiling water quality data, the Environmental Protection Agency also prepares a list of the 25 sampling stations at which the fecal coliform density is highest and dissolved oxygen averages are lowest, based on water quality data.

The worst fecal coliform average for the year ending June 30, 1972—236,570 units per 100 milliliters of water—was found at a sampling station on the Big Muddy River near West Frankfort. The Pollution Control Board standard is 200 units per 100 milliliters of water.

Dissolved oxygen averages for fiscal 1972 were poorest at two stations on the Chicago Sanitary and Ship Canal. An average of 2.1 milligrams per liter of water was recorded at these stations.

Rankings of Illinois river basins by averages of dissolved oxygen and fecal coliform density summarize laboratory results on water taken from 618 sampling stations in fiscal year 1972.

The Division of Water Pollution Control increased the number of sampling locations by 154 from the 1971 total of 464.

The number of routing samples which were taken in fiscal 1972 increased more that 25 per cent over fiscal 1971 sampling. The expansion represents an increased concentration of efforts to upgrade water quality in Illinois and to better protect the health of Illinois citizens.

The EPA has now reached the level of sampling stations necessary to insure effective monitoring of river basins in Illinois. Stations are located at accessible points on major rivers, on their tributaries, and along Lake Michigan.

Fiscal year data comparsions of sampling network activity show the following expansion:

	1971	1972
Number of Stations	464	618
Number of Samples	4,858	5,523

In a continuing effort to provide Illinois citizens more frequent evaluations on the quality of waterways in the state, the EPA is now publishing results of water quality sampling on a quarterly basis. Reports were released annually in the past.

Fecal coliform data have been reported as geometric averages for the first time as prescribed by the Pollution Control Board. Previously arithmetic averages were used.

Illinois Parks and Recreation 14 January/February, 1973