Frequently Asked Questions
1) What is a beach?
For the purposes of coastal recreational water quality monitoring, the
Wisconsin Department of Natural Resources (WDNR)
has defined a beach as “a publicly owned shoreline or land area, not contained in a man-made structure,
located on the shore of Lake Michigan or Lake Superior, that is used for swimming, recreational bathing or other water
contact recreational activity.”
2) When is the beach season in Wisconsin?
The beach monitoring season will be from Memorial Day Weekend through Labor Day Weekend (approximately 14 weeks)
3) Who can I call for more information about beach conditions?
You can contact the local health departments for further information on beach conditions. Contact
information for local health departments can be found on the Contact Information page on this website.
4) How is beach water sampled?
Water Quality Monitoring - A How To Guide – by the Chehalis River Council
5) What signs might I find at the beach?
New sign designs in 2004 were approved by the beach program's Workgroup, which includes representatives from
local health departments, state agencies, and water scientists. The signs are intended to inform the public about
the most current water conditions based on testing for Escherichia coli (E. coli) bacteria.
The U.S. Environmental Protection Agency (USEPA) requires that beaches be
posted with an advisory sign informing the public of increased health risk when a water sample exceeds 235 colony-forming
units of E. coli per 100 milliliters of water.
The Workgroup approved that the green informational
sign shall be posted at all monitored beaches when water tests are below the USEPA standard. Local health departments have
the option of posting the blue “Good” sign together with
the green sign, if they so choose. Some health departments, against the Workgroup’s recommendation, have chosen not to post
the green sign at all.
The Workgroup approved that the yellow “Caution” sign shall be posted when the USEPA health standard is exceeded. This sign remains posted until
the next daily sample shows the conditions have changed.
The Workgroup approved that the red “Closed” sign shall be posted when a water sample shows more than 1000 colony-forming units of E. coli per 100 mL are present,
or under any other conditions that the local health department considers there to be an increased public health risk at the beach.
This sign remains posted until the next daily sample shows conditions have improved.
6) What is E. coli?
Escherichia coli (E. coli) is a bacterium commonly found in natural bodies of water. Some strains of E. coli,
such as E. coli 0157:H7, are associated with potentially deadly food poisoning. But the strain of E. coli
being tested for at coastal beaches in itself poses a low probability of making swimmers ill. Instead, the bacteria serve as
an indicator of the possible presence of other health risks in the water, such as bacteria, viruses, and other organisms. All
warm-blooded animals have E. coli in their feces, which means that if high levels of E. coli are found in beach water
there is a high chance of fecal matter being in the water. For more information, check out the UW-Milwaukee Water Institute at
7) How were the E. coli 235 CFU/100 mL and 1000 CFU/100 mL standards developed?
The standards developed for the Great Lakes in Wisconsin and may be used for inland beaches are:
- If the E. coli count is greater than 1000 MPN/100 mL, the beach is closed.
- If the E. coli count is greater than 235 MPN/100 mL but less than 1000 MPN/100 mL, an advisory is issued.
- If the E. coli count is under 235 MPN/100 mL, the beach has no advisories or warnings issued.
The “Advisory” standard of 235 CFU/100 mL (E. coli in water) was adopted based upon data from three
USEPA studies conducted in the late 1970s (2-4). These studies indicate that E. coli
and/or Enterococci are the best bacterial indicators to assess the risk of acquiring a gastrointestinal illness as a
result of using recreational waters. These levels are the original recommendation of USEPA and they were reaffirmed in a
revisiting of the issue in 2002 (1).
Additional epidemiological studies are set to take place during the BEACH program and should be completed by 2006.
These studies are detailed in the following reports and are available free in *.*.pdf format from the
The epidemiological studies indicated that a level of 235 CFU of E. coli/100 mL of recreational water is approximately equal to
8 cases of gastrointestinal illness per 1000 recreational water users.
The “Closure” level of 1000 CFU E. coli/100 mL was adopted by the WDNR
based upon data from the studies mentioned above and represent a risk of approximately 14 cases of gastrointestinal illness per 1000
recreational water users.
1) USEPA, 2002. Implementation Guidance for Ambient Water Quality Criteria for Bacteria. U.S. Environmental Protection Agency. EPA-823-B-02-003. May 2002 Draft.
2) USEPA, 1986. Ambient Water Quality Criteria for Bacteria–1986. U.S. Environmental Protection Agency. EPA-440/5-84-002.
3) USEPA. 1984.Health Effects Criteria for Fresh Recreational Waters. U.S. Environmental Protection Agency. EPA-600/1-84-004.
4) Cabelli, V. J. 1983. Health effects criteria for marine recreational waters. U. S.
Environmental Protection Agency, Cincinnati, OH. EPA-600/1-80-031.
What is the difference between CFU/mL and MPN/mL? CFU means “Colony Forming Unit” and MPN is “
Most Probable Number”. The traditional membrane filtration tests for bacterial water quality actually count ‘colonies’
of bacteria and thus is reported as CFU. However, the newer defined substrate tests such as Colisure or Colilert report data as MPN which
is a statistical representation of what level of E. coli is likely present in a sample. For the purposes of reporting, these terms
have been used interchangeably.
8) Why E. coli and not Enterococci?
In the study listed as #2 above, E. coli levels were found to have the best correlation with highly credible cases of
gastrointestinal illness in freshwater systems. While Enterococci had the best correlation in marine systems, either E. coli or
Enterococci were deemed acceptable fecal indicators in freshwater systems. In addition to the EPA studies, the
WDNR conducted a study prior to the first BEACH season of 2003 in which 3 state park beaches were monitored for E. coli
and Enterococci. The E. coli yielded the most reliable and consistent results in their study.
9) What illnesses can occur during an E. coli advisory/beach closure?
Here are some microorganisms that can exist in lake water and examples of the symptoms of illness they can cause in humans:
- Bacteria: Gastroenteritis (includes diarrhea and abdominal pain), salmonellosis (food poisoning), cholera.
- Viruses: Fever, common colds, gastroenteritis, diarrhea, respiratory infections, hepatitis.
- Protozoa: Gastroenteritis, cryptosporidiosis and giardiasis (including diarrhea and abdominal cramps), dysentery.
- Worms: Digestive disturbances, vomiting, restlessness, coughing, chest pain, fever, diarrhea.
If you experience these symptoms or any other signs of illness, it is recommended you seek attention from a health care provider
immediately. For more information, see the Centers for Disease Control “Healthy
10) When there is an advisory or beach closure, is the water safe for pets? For adults
vs. kids? For wading vs. swimming?
The USEPA E. coli standards are health risk assessments for human health based on data from adults engaging in
full-immersion bathing. It is advised that people and pets stay out of the water when the “Caution” or “Closed”
advisory signs are posted.
11) Are all Wisconsin Great Lakes beaches being monitored?
There are about 190 public beaches along Wisconsin’s Lake Michigan and Lake Superior coastline. About
113 of these beaches are regularly monitored.
12) Are inland lakes being monitored?
Yes. All inland state parks have been monitoring their recreational bathing waters for E. coli at least once a week.
In 2004, ten popular inland State Parks and Forests beaches were selected for a pilot program to expand the coastal beach program to
inland lakes. These ten beaches are listed below. They were monitored at least 4 times a week and posted with the same signs
used for the coastal program.
The 2004 pilot program was a collaborative effort funded with about $106,000 provided by the WDNR,
Department of Health and Family Services, and the
Wisconsin State Laboratory of Hygiene. In the future, depending on funding, it is hoped the
inland monitoring program can be expanded to other public beaches around the state.
13) Why are some beaches monitored more frequently than others?
The priority for beach monitoring was determined after consulting with the public and doing surveys on beaches.
The number of people using each beach along with environmental factors were considered. “High priority” beaches
are monitored five times a week, while medium priority beaches are monitored at least two times a week and low priority beaches are
monitored once a week or only occasionally. This ranking allows WDNR to target limited funds to
the most popular and at-risk bathing areas.
14) Where can I find a map of beaches in my area?
The WDNR maintains
maps of public coastal bathing beaches on its website.
15) What can I do to help the monitoring program?
Keep your eyes open and report any water quality problems you experience at the beach to local health authorities and the
WDNR. There are many local and regional groups that advocate for clean and healthy beaches such
as the Lake Michigan Federation, the
Lake Superior Alliance, and Keep Our Beaches Open
16) What can I do to stay safe at the beach?
A few simple precautions can help you and your family protect your health and safety at the beach:
- Don’t swallow lake water
- Shower after swimming
- Wash hands before eating
- Pay attention and follow advisory signs
17) What can I do to improve beach water quality in my community?
There are many theories about what causes high levels of E. coli at local beaches. There are steps you can take
to help keep our beaches clean and reduce health risks for everyone at the beach.
Here are some suggestions to help keep our beaches open:
- Don’t swim if you are ill
- Don’t feed the birds
- Dispose of trash in appropriate containers
- Change baby diapers before allowing them to swim
- Don’t dump household chemicals or wastes in street drains
- Avoid using excess fertilizers or pesticides on your yard
- Report possible sources of contamination to local authorities/WDNR
18) How is the Wisconsin beach program funded?
The Wisconsin coastal beach monitoring program is funded by the USEPA under the federal Beach Act. And additional funds from the
To learn more about the BEACH Act, see the USEPA Beach Act website.
To learn more the USEPA and Beaches, see the USEPA beach website.
19) What role does WDNR
play in beach monitoring?
The Wisconsin Department of Natural Resources (WDNR) is the link between the federal
government and local health departments, and helps to set the standards for the beach program and funnel federal funds to the
local authorities. The WDNR convened a Workgroup in 2001 that has developed and continually
reviews the implementation of the program, and is composed of representatives from local health departments, state environmental and
health agencies, environmentalists, and water scientists from around the state.
20) How can I make a comment about the beach program?
Access our “
Questionnaire” from the Beach Health website. You can make comments about the webpage and the program in
general as well as provide other input to help improve the program!