When the Oakland County Health Division’s 2012 beach monitoring program wrapped up earlier this year, there were a few more county beaches closed and for a slightly longer total of time when compared to figures from the 2011 program.
This year, the Health Division monitored 45 public beaches on 37 Oakland County lakes for potentially unsafe levels of bacteria in beach water. The annual beach monitoring program began on June 4 and ended on July 27.
Analysis of water samples collected from the targeted beaches resulted in the closure of six beaches for a total of 11 days during 2012.
Here’s a detailed look at the county’s 2012 beach closures:
• E.V. Mercer City Beach on Walled Lake in the city of Walled Lake was closed on June 12 with a bacteria count of 547 colonies. The beach was reopened the next day when follow-up testing indicated a bacteria count of 23 colonies.
According to the Michigan Department of Environmental Quality’s (DEQ) BeachGuard database on beach water quality monitoring, wildlife was the source of bacteria that prompted the closure of the beach. The beach’s last closure was in 2010.
• Thelma Spencer Beach on Carter Lake in Rochester Hills was closed twice during the 2012 monitoring program. The first closure took effect on June 13 due to a bacteria count of 762 colonies. The beach was reopened the following day after subsequent testing revealed a bacteria count of 22 colonies.
The beach was closed again on July 6 with a bacteria count of 308 colonies. Again, the beach was reopened the next day after a second round of testing found 11 bacteria colonies in beach water samples.
The BeachGuard database states wildlife was the source of high bacteria levels that closed the beach on June 13, and storm water runoff was the source of bacteria requiring the July 6 closure. The beach was last closed back in 2008.
• The Groveland Oaks County Park’s Paradise Beach on Stewart Lake in Groveland Township was closed on July 18 with a bacteria count of 485 colonies. The beach was allowed to reopen the following day after testing showed just 23 bacteria colonies in beach water samples.
The DEQ’s BeachGuard database cites an unknown source as being responsible for the high bacteria levels that forced the beach closure. No past closure was listed for Paradise Beach on the BeachGuard database.
• The Seven Lakes State Park beach on Big Seven Lake in Holly was closed on July 18 after testing revealed a bacteria count of 531 colonies. The beach was reopened the next day following a second round of testing that indicated 24 bacteria colonies in beach water samples.
The DEQ’s BeachGuard database cites an unknown source as being responsible for the high bacteria levels that forced the beach closure. The beach was last closed in 2007.
• The Haas Lake Park No. 1 beach on Haas Lake in Lyon Township was closed on July 24 due to a bacteria count of 328 colonies. The beach was reopened the next day with a bacteria count of 4 colonies.
Storm water runoff was the source of high bacteria levels that prompted the beach’s closure, according to the DEQ’s BeachGuard database. No past closures of the Haas Lake Park No. 1 Beach were cited by BeachGuard.
• Martindale Beach on Kent Lake inside Kensington Metropark in Milford Township was shut down on July 24 after water sample testing showed 507 bacteria colonies. The follow-up testing results indicated 1,176 bacteria colonies in beach water samples and required the beach to remain closed on July 25. The beach was allowed to reopen on July 26 after a third round of testing found 204 bacteria colonies in beach water samples.
The DEQ’s BeachGuard database cites wildlife as being the source of bacteria levels leading to the beach closure. No previous closures for Martindale Beach were cited by BeachGuard.
To access the BeachGuard database, visit www.deq.state.mi.us/beach.
In 2011, a total of four Oakland County public beaches on four lakes were closed for a total of five days because of high bacteria levels found in beach water samples. In 2010, 11 beaches were closed for 16 days, which is significantly different from 2006, when 22 beaches were closed for a total of over 90 days.
Budget cuts have forced the Health Division to scale back the number of beaches it monitors each year from over 100 public and semi-public beaches.
The Health Division tests beach water samples for the presence of E. coli bacteria, although most strains of E. coli are harmless. However, because E. coli lives in the intestinal tracts of warm-blooded animals, including birds and humans, it’s often excreted in feces. This makes E. coli a useful indicator of fecal pollution, which can contain other, more harmful pathogens including other bacteria, viruses, and protozoa.
According to the Michigan Department of Environmental Quality (DEQ), studies of fresh water bathing beaches have established a direct relationship between the density of E. coli in water and the occurrence of swimming-associated gastroenteritis. The recognition of this relationship has led to the development of criteria that can be used to establish recreational water standards.
These standards specify that water samples from monitored beaches must meet a one-day standard of no more than 300 E. coli bacteria colonies per 100 milliliters of water, and a 30-day geometric average standard of no more than 130 colonies per 100 milliliters of water. If a beach water sample exceeds either of those standards, the beach is closed until bacteria levels drop.
Typically, bacteria levels fall off within 48 hours, as wind and wave action, as well as ultraviolet light from the sun work to reduce bacteria levels. However, sometimes it can take longer for bacteria to die in a freshwater environment, especially if the water is stagnant.
Since illness can occur from swallowing water containing even minuscule amounts of fecal matter, it’s important to determine as soon as possible if a local beach is contaminated — which is why the Health Division annually collects water samples at beaches for testing to make sure the water is safe for swimming.
In order to implement the 2012 beach monitoring program, the Health Division employed four paid summer college interns to collect beach water samples at the 45 targeted public beaches. The interns are typically environmental health science students who require internships to complete their degrees.
Each of the 45 beaches targeted for testing this year were sampled at least once a week for the duration of the monitoring program.
If the lab results show E. coli bacteria levels exceed the state contamination standards, the Health Division closes the beach by sending an intern to post a sign at the beach and by notifying the beach’s contact person.
A variety of sources can contribute bacteria and other pathogens to surface water resources. Sources of bacterial contamination include combined sewer overflows, which are releases of raw or inadequately treated sewage from systems designed to carry both sewage and stormwater to wastewater treatment plants. When the volume of the combined wastewater is greater than the treatment plant capacity, the excess untreated sewage and stormwater are discharged into nearby waterways.
Sanitary sewer overflows are another potential source of bacteria in beach water. They are discharges of raw or inadequately treated sewage from systems designed to carry domestic sanitary sewage, but not stormwater. According to the DEQ, systems that contain cracks, obstructions, illegal stormwater 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 treatment plants into surrounding waters, particularly during extreme hydrologic events.
Failing septic systems also are a source of the bacteria that can force a beach closure.
Large congregations of waterfowl near beaches and animal waste runoff from farms and fields can work in tandem with stormwater runoff to contribute to elevated bacterial levels.
People can help prevent beach water pollution by conserving water; redirecting runoff; maintaining their septic systems properly; and properly disposing of animal waste. People who use a beach also shouldn’t feed the waterfowl or leave their trash because both attract animals that may leave behind fecal matter.