Beach Monitoring

Where can I find e.coli readings for the parks beach access points?

For information on e.coli readings at the parks various beach access points visit the Indiana Department of Environmental Management. (Note: The national park service does not operate the "Indiana Department of Environmental Management" site.)


What are Indiana’s Water Quality Standards for E. coli?
Indiana’s Water Quality Standards (327 IAC 2-1.5-8 (e)), specify that for full body contact, E. coli counts shall not exceed 235 colonies per 100 milliliters as a one-time sample or 126 colonies per 100 milliliters as a geometric mean of not less than 5 samples equally spaced over a 30 day period. “Full body contact” means the direct contact with the water to the point of complete submergence (i.e., swimming).

How can I find out the Status of other Lake Michigan beaches in Indiana?
For information concerning Indiana’s other beaches visit Information concerning Indiana Dunes State Park is also available by calling (219) 926-1952.

What are swimming related illnesses?
According to the Centers for Disease Control and Prevention (CDC), swimming, one of the most popular activities in the country, is a fun, active, and healthy way to spend leisure time. Every year, millions of people visit “recreational water” sites, such as swimming pools, water parks, hot tubs, lakes, rivers, or the ocean. Over the past century, the use of modern disinfection systems in pools and environmental improvements in our lakes, rivers, and oceans has improved the quality of recreational water. Despite this, however, there are certain illnesses that are associated with swimming. These swimming related illnesses are caused by microorganisms (e.g., bacteria, viruses, and protozoa) in the water.

According to the CDC, of the different illnesses that may be contracted during recreational water activities, gastrointestinal illness is the primary concern. The main route of exposure to illness-causing organisms in recreational waters is through direct contact with water while swimming, most commonly through accidental ingestion of contaminated water. Gastroenteritis is a term for a variety of diseases that affect the gastrointestinal tract and are rarely life-threatening. Symptoms of the illness include nausea, vomiting, stomachache, diarrhea, headache, and fever. Although the most common effects of bathing in contaminated water are illnesses affecting the gastrointestinal tract, other illnesses and conditions affecting the eye, ear, skin, and upper respiratory tract can be contracted as well.

How do beach managers monitor the water quality at their beaches?
In lakes and rivers, it is very difficult to detect the presence of the microorganisms that actually cause swimming related illnesses. Therefore, beach managers test for levels of bacteria in the water that can be associated with contamination from sewage or other sources of contamination and which may indicate the potential presence of human pathogens in the water. These “indicator” organisms generally do not cause illness directly. The most common indicator bacteria monitored in freshwater is Escherichia coli (E. coli). Although most E. coli do not cause illness, some less common pathogenic E. coli strains do cause illness (often associated with food contamination). In addition to E. coli have been show to live naturally in soils and sands, and thus are not always indicative of contamination. Generally, it is the level of non-pathogenic E.coli that is reflected in the bacteria levels reported for water quality monitoring. The U.S. Environmental Protection Agency completed studies that correlated the levels of indicator E. coli to swimming related illnesses.

How do single sample E. coli levels relate to swimming related illness rates in EPA’s studies?

E. coli level of a single sample

Reported gastrointestinal illness rate?


8 in 1,000 swimmers (at the 75% C.L.*)


9 in 1,000 swimmers (at the 75% C.L.)


10 in 1,000 swimmers (at the 75% C.L.)


8 in 1,000 swimmers (at the 95% C.L.)


9 in 1,000 swimmers (at the 95% C.L.)


10 in 1,000 swimmers (at the 95% C.L.)
*In EPA’s studies, for a gastrointestinal illness rate of 8 in 1,000 swimmers, there was a 75% probability that the concentration of E. coli in any single sample would be 235 or less (i.e., the 75% Confidence Level) and there was a 95% probability that the concentration of E. coli in any single sample would be 576 or less (i.e., the 95% Confidence Level).
What you can do to help protect your health and that of other beach-goers:

At the Beach

  • Do not swim or play in streams or ditches flowing into Lake Michigan (they contain run-off that is more likely to be contaminated).
  • Do not feed the seagulls, geese, or other animals on the beach. The feces from these animals as well as from dogs can increase microorganisms on the beach and in the water. At beaches where dogs are allowed, it is critical to pick-up pet waste and dispose of properly.
  • Place all litter in trash cans provided (or properly dispose of it after leaving the beach). Trash left out on the beach is unsightly, can be hazardous, and will attract animals.
  • Take young children on bathroom breaks and check diapers often. Waiting to hear "I have to go" may mean that it's too late.
  • Do not swim when you have diarrhea and don’t allow children in dirty diapers to swim. Micro-organisms can spread through the water and make other people sick.
  • When going to the beach or for other outdoor activities, keep two items handy—a sunscreen lotion and a hand-sanitizing lotion (62% ethyl alcohol). Use an appropriate sun screen before going outside and use the hand-sanitizing lotion after swimming or playing in the sand. (Microorganisms are present in the water, sand, and soil.)

At Home

  • Support the restoration of wetlands. Wetlands help to clean and protect Lake Michigan and can reduce the level of microorganisms. Healthy wetlands will lead to open beaches.
  • Keep your septic system properly maintained.
  • Reduce your water use, especially during heavy rain events, when local sewage treatment plants get overloaded. Postpone your laundry chores when it is raining.
  • Pick up pet waste and dispose of it properly. Don't hose waste into storm drains. Pet waste contains microorganisms that can spread disease. Help keep your yard, neighborhood, and Lake Michigan, healthy and clean.

Additional Resources
The Centers for Disease Control and Prevention (CDC):

The U.S. Environmental Protection Agency Beachgoer's Guide

Human Health Impacts of Sewer Overflows:


Swim Safe (Some Tips from the CDC) --
• Know the local weather conditions and forecast before swimming or boating. Strong winds and thunderstorms with lightning strikes are dangerous to swimmers and boaters.

• Watch for dangerous waves and signs of rip currents (e.g., water that is discolored and unusually choppy, foamy, or filled with debris). If you are caught in a rip current, swim parallel to the shore. Once out of the current, swim toward the shore.

• Make sure an adult is constantly watching children swimming or playing in or around the water. Do not read, play cards, talk on the phone, or engage in any other distracting activity while supervising children.

• Always swim with a buddy.

Last updated: June 16, 2020

Contact the Park

Mailing Address:

1100 North Mineral Springs Road
Porter, IN 46304


(219) 395-1882
Indiana Dunes Visitor Center phone number.

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