E-coli Oakland County
Health Division looking out for bacteria at 44 beaches
As summer approaches, many Oakland County residents will take advantage of the numerous lakes in the area to have some fun in the sun. Yet, that good time frolicking in the sand and splashing through the waves can be tarnished by subsequent gastrointestinal problems caused by exposure to certain pathogenic microorganisms.
Most people have probably heard of beaches closing throughout the summer due to high levels of E. coli bacteria, and yet it’s not E. coli that most beach-goers have to fear. In fact, most strains of E. coli are harmless — with a few exceptions, such as the infamous O157:H7 strain, which is the strain most related to E. coli outbreaks in foods.
However, while most strains of E. coli are harmless, they can serve as a useful tool for water quality monitoring. Since E. coli lives in the intestinal tracts of warm-blooded animals, including birds and people, it’s often excreted in feces. This makes it a useful indicator of fecal pollution, which can contain other harmful pathogens — including bacteria, viruses, and protozoa — according to Dr. Joanna Pope, a post-doctoral fellow at Michigan State University working in the lab of Dr. Joan Rose.
Rose is the Homer Nowlin Chair in Water Research at Michigan State University and an international expert in water microbiology, water quality and public health safety.
“In human fecal material, pathogens can include norovirus, salmonella and pathogenic strains of E. coli, such as O157:H7. It may also be possible to detect other pathogens such as Cryptosporidium or Giardia. These pathogens can cause acute symptoms such as gastrointestinal illness (vomiting and/or diarrhea) and in some people, more chronic conditions such as kidney disease, skin rashes or longer-term fatigue,” Pope explained.
She added that the types of pathogens found in fecal matter can be “highly variable, both in type and abundance” depending on the source of the fecal material.
E. coli can come from a number of sources, such as wastewater treatment plants, leaking septic tanks, farms, wildlife, and storm water.
Pope explained that sometimes E. coli can come from a mixture of multiple sources.
“We usually describe these sources as being ‘point-source,’ which is something readily identifiable such as a waste pipe discharging to a beach, or ‘non-point,’ which is something more diffuse, such as surface water that runs off the ground to the beach when heavy rain occurs.”
And if E. coli is present in high levels, it’s most likely that other pathogens may be in the water and sand, as well.
Yet, Pope said it’s very difficult to determine “a general risk frequency” with regards to beaches because of the multiple factors involved.
These factors include behavior, such as swimming vs. playing in the sand; susceptibility of the person, such as the difference between children and adults; and the weather conditions, like on-shore vs. offshore winds.
“All of these factors can influence the possibility of health risks for a particular beach,” Pope said. “EPA (Environmental Protection Agency) studies along Lake Michigan where wastewater influences the shoreline suggests that 10 percent of the people over the swim season may get sick.”
However, determining water quality by monitoring E. coli can help in determining the possibility of people getting sick.
“E. coli monitoring is important because it helps local health departments, state and federal agencies advise beach-goers about the quality of the water. It can also help identify areas where the water quality is impaired and put into place strategies that can improve the water quality by reducing pollution,” Pope said.
According to the Michigan Department of Environmental Quality (DEQ), epidemiological 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, and the recognition of this relationship has thus led to the development of criteria that can be used to establish recreational water quality standards.
These standards specify that water samples from monitored beaches must meet a one-day standard of no more than 300 bacteria colonies per 100 milliliters (ml) of water, and a 30-day geometric average standard of no more than 130 bacteria colonies per 100 ml. If a water sample exceeds either of those standards, a beach is closed until bacteria levels drop.
Typically, bacteria levels will drop within 48 hours as wind and wave action, as well as ultraviolet light from the sun, help reduce bacteria levels.
However, there is an exception to every rule, and sometimes it may take longer for bacteria to die in a freshwater environment, especially if the water is stagnant.
Because illness can occur from swallowing water that contains minuscule amounts of fecal matter, it’s important to determine as soon as possible if a local beach is contaminated — which is why many county health departments routinely collect water samples at beaches to make sure the water is safe for swimming.
Oakland County is no exception.
This year the Oakland County Health Division will be testing water samples collected at 44 public beaches on 37 county lakes with the help of four summer college interns.
“These interns are students usually studying environmental health sciences who need internships for a completion of a degree,” said Mark Hansell, the Environmental Health Services Unit supervisor for the Oakland County Health Division.
The monitoring program will start on June 6 this year and continue for eight weeks until the end of July. Hansell said that eight weeks is usually the standard for the beach monitoring program, which is primarily based on the interns’ school schedules.
“We typically monitor through the last week of July. However, if there were beaches that were still having water quality problems, then we would continue to sample until problems clear up. In that case, we might monitor for 10 weeks occasionally, but only for the beaches having those issues,” he said.
Each of the 44 beaches will be sampled at least once a week for those eight weeks.
“The interns do an initial survey of the beach, looking for environmental concerns,” Hansell said. They then wade out into the lake and start collecting samples from three areas of the bathing area — the center of the beach, the right side of the beach, and the left side of the beach. And then the samples are brought back to the lab for analysis.”
“E. coli laboratory methods typically involve collecting water samples, sometimes filtering the water and culturing — growing — the bacteria to give a number of E. coli colonies, a group of cells that have grown up into one large visible number of cells,” Pope said. “We typically report E. coli as colony forming units (CFU) per 100 ml, which allows comparisons in the water quality at different beaches.”
According to Pope, E. coli is relatively easy and inexpensive to grow in a laboratory, which along with its presence in water makes it a “good microbial candidate” for frequent water quality testing.
If the lab results from beach water testing exceed the state standards previously mentioned, then the Health Division will close a beach by sending an intern to post a sign at the beach and by notifying the beach contact person. The beach closings are then also posted online at the Oakland County website, oakgov.com.
The beach will reopen once E. coli levels are once again below the state-set standards.
Although Oakland County has 279 active beaches that are public or semi-public, budget shortfalls have forced the Health Division to reduce the size of its summer staff. This means that the county’s beach monitoring program has dwindled since 2007, when 120 beaches were tested during the summer.
Furthermore, while the county used to have a five-year rotation for monitoring water quality at semi-public beaches — those operated by property owner associations and located in neighborhoods — the county now has the resources to only collect and analyze water samples from public beaches.
“We limit sampling to public beaches because these are beaches designed for public swimming,” Hansell said. “With semi-public beaches, the original intent of the beach wasn’t a bathing beach. So the grooming and upkeep of the beach isn’t as good as it is at a public beach that is specifically designed for swimming.”
However, the Health Division is still encouraging the managers of privately-owned beaches to have water samples collected and analyzed at the county’s lab, free of charge.
“We have all the materials at the offices to get them started,” he said. “They can pick up the materials and directions on how to collect samples and then return the bottles to the lab, which will do the analysis for free and mail the results out.”
Unfortunately, he said, “not as many (private and semi-public beaches) as we would like take advantage of it,” which can be seen when comparing the Oakland County beach closings over the past five years.
In 2010, 11 beaches were closed for a total of 16 days. This is vastly different from 2006, when 22 beaches were closed for a total of more than 90 days.
Back in 2006, more semi-public and private beaches were being monitored by the Health Division, which Hansell said most likely accounts for the difference in results.
This is one of the reasons why Hansell strongly encourages lake associations to take advantage of the free lab analysis by collecting their own beach water samples.
Others may want to take advantage of the free lab analysis, as well, to test water from their favorite swimming holes that may not be part of the main beach.
According to the DEQ, it’s a popular misconception that if one area of a lake is contaminated, then the whole lake is contaminated. Bacteria contamination originates from conditions or factors present on or near the shore in the immediate vicinity of the contamination. Two beaches on opposite ends of a lake that have different on-shore conditions will not have the same bacteria levels. This is why it’s important for private homeowners who swim near their house to periodically collect water samples where they swim and not rely on results from a beach down the road. Since contamination originates on-shore, it’s generally considered safer to swim in deeper areas away from the shoreline, because wind direction and wave action could trap bacteria against the shoreline.
The DEQ provides administrative and technical support for beach monitoring programs like Oakland County’s. The DEQ also administers federal and state funds allocated to the local health departments for their beach monitoring programs.
When selecting which counties will receive the grants, the DEQ considers all of the following:
• Location and frequency of beach use;
• History of beach monitoring and bacterial contamination;
• Ability to communicate results to the public in an efficient manner;
• Ability to respond and take appropriate action in the event of beach contamination;
• Proximity of beach to a known bacterial contamination source;
• Innovativeness and feasibility of a proposed project; and
• Ability to reduce time delays between sampling and results.
In 2009, for the 2009 and 2010 beach testing program, the DEQ awarded $187,424 in grants to 14 health departments across the state testing 149 beaches. Oakland County didn’t receive any state grant money for beach water monitoring in 2009 or 2010.
The funding for those grants was made available through the Clean Michigan Initiative-Clean Water Fund.
Hansell said Oakland County applied for a grant from the state this year to help fund its beach monitoring program, but he’s yet to hear whether the county will receive a grant.
Meanwhile, beach testing will continue to occur on the 44 designated Oakland County public beaches to monitor for potentially harmful levels of bacteria.
However, there are a few things residents can do to ensure that E. coli levels remain low.
Individuals can help prevent beach water pollution by conserving water; redirecting runoff; using natural fertilizers and compost in gardens; maintaining their septic systems properly; and properly disposing of animal waste, litter, toxic household products and used motor oil. People who use a beach also shouldn’t feed the waterfowl or leave their trash behind, as both continuously attract animals that may leave behind fecal matter.
As for remaining healthy while enjoying the beach, it’s always recommended to wash your hands after swimming or playing in the sand to avoid any invisible fecal matter from entering your system.
Pope also recommends searching the state of Michigan’s beach database to see which beaches are tested regularly for E. coli and to get better informed about the quality of the water.
“If a beach closure or advisory is issued, then it is recommended that people do not enter the water,” she said. “It is also a good idea not to swim near discharge pipes, especially after heavy rain. If the water is very turbid (murky) it could mean that the microbial quality is reduced and going into the water is not recommended. Finally, the public can learn about how wastewater and storm water is handled in their watersheds that might affect key beaches and support efforts to remediate the problems.”