Healthy Beaches, Healthy Lakes

Healthy coastal areas are of course important to fish and wildlife, but they are also vital to the quality of life in and the economy throughout the Great Lakes basin. For most people, the beach is a place for relaxing, making memories or connecting with nature. However, Great Lakes beaches, streams and rivers are threatened by pollution, contamination and a changing climate. This lesson explores threats to Great Lakes beaches like bacterial contamination, pathogens and harmful algal blooms as well as stewardship efforts like beach cleanup programs that help keep beaches safe and healthy. While humans often play a role in contributing to beach contamination, people work equally as hard to maintain and improve water quality.

Grade Levels:

  • National Science Education Standards: 5-8 grade
  • Michigan Grade Level Content Expectations: 5-7 grade

Performance Expectations:

  • MS-ESS3-3: Earth and Human Activity: Apply scientific principles to design a method for monitoring and minimizing human impacts on the environment.

For alignment, see: Healthy Beaches, Healthy Lakes, NGSS Summary

Lesson Objectives

  • Describe different sources of beach contamination.
  • Develop a hypothesis about the increase of beach closures.
  • Discuss several ways people can help protect beaches and water quality.


Protecting Michigan’s water quality depends on the efforts of pollution prevention programs around the state. Beach monitoring programs review water quality data, including the number of beach closures or advisories. This information is used in federal, state and local pollution prevention programs to identify sources of pollution that affect beach water quality.

The following are several examples of what can detract from beach health and water quality throughout the Great Lakes:


Pathogens are microorganisms (bacteria, protozoans or viruses) that cause disease. Most waterborne pathogens are found in the feces of humans and other warm-blooded animals. Gastroenteritis is the most common illness associated with swimming in contaminated water. The severity of the illness depends on the amount of exposure and the type of pathogen.

Pathogen Example: E. coli

E. coli is a rod-shaped bacterium that is found in the lower intestines of warm-blooded organisms. Most E. coli is harmless and only a few strains directly cause illness. Because E. coli is strongly associated with human (and other mammal and bird) intestines, it is a good indicator of the presence of sewage and fecal contamination in a location. It is also a good indicator of other bacteria and viruses that are difficult to measure directly.

EPA requires that beaches be closed when E. coli levels are elevated. This is the leading cause of beach closures in the Great Lakes. If bacteria counts are elevated enough to cause a risk of illness in humans, the beach is closed and an advisory is issued. One problem with testing for E. coli levels is that it requires a 24 hour incubation period. This can result in people swimming in contaminated water before beaches are closed. However, scientists are working on developing methods to detect contamination faster and more accurately in order to ensure human and beach health.

Sources of Bacterial Contamination

  • Combined sewer overflows (CSOs) are discharges of raw or inadequately treated sewage from sewer systems that are designed to carry both domestic sewage and stormwater to wastewater treatment plants. When a storm occurs and the volume of the wastewater is larger than what the plant can process, the excess untreated sewage and storm water are discharged into local waterways.
  • Sanitary sewer overflows (SSOs) are discharges of raw or inadequately treated sewage from municipal sanitary sewer systems, which are designed to carry domestic sanitary sewage but not stormwater. Systems that contain cracks, obstructions, storm water connections, or that are undersized with sewers and pumps too small to carry all the sewage may leak or overflow raw sewage from manholes, bypass pump stations and the treatment plants into the surrounding waters, particularly during extreme hydrologic events like a large amount of rain in a short time or flooding.
  • Failing septic systems can leach or runoff contaminants into the waterways, causing bacterial contamination.
  • Urban stormwater runoff from roads, roofs, construction sites, parking lots, etc., may contain fecal matter from pets and wildlife.
  • Excessive waterfowl feces near beaches as well as animal waste runoff from farms and fields can contribute to elevated bacterial levels.
  • Illicit connections of pipes containing sewage to storm sewers or surface waters are also a potential source of bacterial contamination.

Harmful Algal Blooms

Algae are an important component of a healthy, functioning ecosystem. However, when certain conditions are present, such as high nutrient or light levels, these organisms can reproduce rapidly. This dense population of algae is called a bloom. Some algal blooms are harmless, but when the blooming organisms contain toxins, other noxious chemicals or pathogens, it is known as a harmful algal bloom or HAB. Harmful algal blooms can kill fish, foul coastlines and produce conditions harmful to humans, pets and wildlife. To learn more about HABs in the Great Lakes, see: HAB Fact Sheet (PDF)

What can People do About It?

Beach Clean-Up and Monitoring Programs
Adopt-a-Beach™ is a program that was created by the Alliance for the Great Lakes, an organization that works to conserve and restore the world’s largest freshwater resource through policy, education and local efforts. Adopt-a-Beach chapters operate along the coastlines of four of the five Great Lakes.

More than 9,000 volunteers — including schools, businesses, individuals and families — participate in the program. Teams conduct litter removal and monitoring, and also complete a beach health assessment form that includes science-based observation and testing. Information collected by teams is entered into the Alliance for the Great Lakes’ online database system and can be used for education, to share with local beach authorities, and to improve our beaches.

To learn more about Adopt-A-Beach program, check out this article.

Local Watershed Groups
Do you know what watershed you live in? Find out! Often there are active regional watershed groups that offer opportunities for volunteers to get their hands wet. Typically this will involve gathering water samples or counting some kind of water quality indicator species, like certain types of insects.

Use Ecologically Safe Products
Using some common household items can contribute to the decline of water quality locally as well as in the Great Lakes. For example, cleaning supplies or fertilizers that get sent down the drain or are collected and transported by runoff when it rains can contribute to algal blooms and muck. Nitrogen, phosphorus and ammonia are three compounds that are commonly found in household cleaners and that can be detrimental to water quality. Consumers should look for products that use other ingredients or consider making their own environmentally friendly products for use around the house.


Alliance for the Great Lakes: Improved Enumeration Methods for the Recreational Water Quality Indicators: Enterococci and Escherichia coli. March 2000. United States Environmental Protection Agency Office of Science and Technology. Washington, D.C. EPA/821/R-97/004 Michigan Beach Monitoring Year 2009 Annual Report. April 2010. Michigan Department of Natural Resources and Environment Water Bureau. Lansing, MI. MI/DNRE/WB-10/018.