Water Reclamation Plants

 

In 1919, the Board of Commissioners passed an ordinance committing the District to the construction and operation of sewage treatment plants to protect and preserve Lake Michigan, our source of drinking water for six million people living in Chicago, Cook County communities, and neighboring counties today.

The boundaries of the Metropolitan Water Reclamation District include more than five million residents of Cook County. These people, plus the thousands of industries within the District, generate 1.4 billion gallons of wastewater each day.

The District is divided into seven service areas. Each sends its wastewater to a different treatment plant through the sewer systems. These seven plants range in capacity from 1.2 billion gallons per day at the Stickney Plant, the world's largest, to 2.3 million gallons per day at the Lemont Plant.

A wastewater processing facility usually contains two treatment plants. One is for processing the wastewater while the other is for treating the solids residue (sludge) captured during the first process.

Approximately 454 billion gallons were treated at the District plants during 2017. These plants have been very successful in meeting the National Pollutant and Discharge Elimination System permit limits. These limits are designed to protect and enhance the quality of our waterways.

The 2017 average plant flow, effluent values, and permit compliance for each plant are presented below in Table 1.

Table 1 2017 Operating Data Summary

Plant

Flow
(MGD)

Effluent (mg/l)

Permit
Violations

Permit
Compliance

CBOD

SS

NH4-N

Stickney WRP

677

2

5

0.5

1

99.94%

Calumet WRP

256

3

6

0.4

0

100%

O'Brien WRP

232

2

6

0.6

0

100%

Kirie WRP

41.77

2

2

0.3

0

100%

Egan WRP

23.9

2

2

0.1

0

100%

Hanover Park WRP

9.50

3

5

0.3

0

100%

Lemont WRP

2.56

4

8

-

0

100%

CBOD Carbonaceous Biochemical Oxygen Demand
SS Suspended Solids
NH4-N Ammonia Nitrogen

How does this compare with other facilities across the U.S.?

About 19,600 public-treatment facilities released about 35,000 Mgal/d (Million Gallons per Day) of treated wastewater nationwide during 1990. Nationally, an average of from 1 to 2 million gallons of treated wastewater per public-treatment facility was returned daily to streams or other surface-water bodies. In addition, 928 Mgal/d of treated wastewater was reclaimed for beneficial uses such as irrigation of golf courses and public parks.


— U.S. Geological Survey. Estimated use of Water in the United States in 1990.