Beach Water Quality F.A.Q.'s
- Can I determine if swimming is not allowed before going to the beach?
- How do I know if the beach water is safe?
- How does Combined Sewer Overflow (CSO) affect the water?
- What can I do to assure the best water quality at the beach?
- How do the bacteria get in the water?
The City of Evanston’s web site will include a notice on the Beach Status Page if a swimming area is closed by the Evanston Health & Human Services Department.
The Dempster Street Beach Office is open from 10:00 a.m. to 7:30 p.m. seven days a week during the beach season. To reach a member of the Beach Office staff directly, please call 847.866.4167.
How do I know if the beach water is safe?
No one can guarantee the quality of natural bodies of water. The sampling that the Department conducts indicates the water quality only on the particular day the sample was collected and at that specific location. Those sample results are not usually known until the day after the sample was collected. The Department recommends not entering the water if it is very murky or turbid, if it has an odor or if there has been a heavy rainfall within the past 24 hours. Beach patrons should not drink the water and should not enter the water if they have any open sores or skin infections, or are experiencing diarrhea.
How does Combined Sewer Overflow (CSO) affect the water?
The Metropolitan Water Reclamation District of Greater Chicago website displays a color coded map of Combined Sewer Overflow events on the entire Chicago Area waterways, including the North Shore Channel. This map is updated daily and graphically shows when the channel is unsafe for limited contact recreation use. These activities include recreational boating (kayaking, canoeing, jet skiing) and any limited contact incident to shoreline activity, such as wading and fishing.
What can I do to assure the best water quality at the beach?
While some contamination may occur by nature and cannot be controlled, there are several things that beach patrons can do to assure the best water quality:
- Be sure infants wear tight fitting rubber or plastic pants if they enter the beach water
- Don’t encourage water fowl by feeding ducks or geese
- Encourage children to use the toilets frequently.
What is E. coli?
Escherichia coli (E. coli) bacteria live in the digestive systems of humans and other warm blooded animals. Therefore, they are found in sewage and other wastewater. Most strains are not harmful, but some are, and they can indicate the presence of other disease-causing bacteria.
Why are beaches monitored by the Evanston Health & Human Services Department?
The Evanston Health & Human Services Department collects and analyzes samples of beach water seven days a week during the beach season. If the results exceed the Department’s limits, the risk of illness increases and the beach is required to be closed.
When will swimming areas re-open?
Factors such as natural die-off, wind and wave action, and ultraviolet light from the sun will help to reduce the level of bacteria. The length of time this takes is unpredictable; however, it is usually less than 24 hours.
The water needs to be resampled and the samples from both the shallow and deep areas must be below 235 cfu of E. coli/100 ml. before the beach will be allowed to re-open. It takes 24 hours after receipt of the samples to determine the bacteria levels.
How do the bacteria get in the water?
There are a variety of sources that contribute bacteria to surface water:
- Illegal sewer connections to storm sewers or roadside ditches, or direct discharges to the lake
- Malfunctioning sewage disposal systems
- Combined and sanitary sewer overflows
- Storm runoff following a rain
- Wild and domestic animal waste
- Agricultural runoff
- Bather defecation
What type of illness can you get from swimming in contaminated water?
Is it necessary to report any illness that might be associated with the use of the beach?
The Evanston Health & Human Services Department should be notified if you become sick after swimming at the beach. Illnesses will be reported to the Illinois Department of Public Health for investigation. Early notification can prevent hundreds of additional people from becoming ill.
Concerns about Evanston’s beaches or lakefront operations should be directed to:
City of Evanston Parks, Recreation and Community Services Department
2100 Ridge Ave.
Evanston IL 60201
Concerns about water quality should be directed to:
City of Evanston Health & Human Services Department
2100 Ridge Avenue
Evanston, IL 60201
The source for much of the information in this page is:
Illinois Department of Public Health
Division of Environmental Health
525 W. Jefferson St., 3rd floor
Springfield, IL 62761