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Avoid E. coli by staying dry after a storm

Water tests sometimes show high levels of E. coli bacteria in local waters. The bacteria can appear at any time, sometimes for no obvious reason. That’s why the water at 16 area beaches is tested weekly all summer.

Routine sampling on June 23, for example, found E. coli levels at eight times safe amounts at Northport Marina Beach. At that level, Michigan Environment, Great Lakes & Energy standards recommend no body contact with the water. The Benzie Leelanau Health Department tested seven other beaches that day, all of which fell within safe limits.

Follow-up tests typically show that levels decline in a day or two. That was true in the Northport example — levels were safe a day later.

The testing system — and therefore the ability to inform the public about E. coli incidents — is imperfect. Current testing methods take 18 hours to generate a result. So public notice of high E. coli levels are delayed a day.

Equipped with common sense and a tidbit of knowledge, though, swimmers can keep themselves out of potentially dangerous waters — most of the time. E. coli tends to show up most often right after a big rainstorm.

It makes sense to stay dry the day after a serious summer shower.

Health Department of Northwest Michigan Director of Environmental Health Dan Thorell says heavy rainfall can flush out municipal storm drain systems.

The stuff flushed out includes waste from ducks, geese and any animal that deposits scat in the wild. Waste collects during dry periods, scattered across fields, forests, yards and roads. Light rains transport some of that animal waste, which can carry E. coli bacteria, into storm drain systems. Heavy rains flush out the system, scouring it clean and carrying everything — including E. coli — into Grand Traverse Bay and Lake Michigan.

It takes time for the big lake to digest the stuff that nature — and storm drain systems — feed it. Sunlight breaks down the bacteria in open water. Add in the time it takes for test results to come back, and there’s a built-in period soon after rainstorms when it might not be safe to go in the water.

Elevated E. coli levels indicate surface water fecal contamination — which poses a threat to public health and can cause serious illness, especially in young children and people with compromised immune systems.

That’s why the region’s health departments have been monitoring E. coli levels weekly for two decades.

Much testing on Lake Michigan is financed through the U.S. Environmental Protection Agency’s BEACH Act. In Michigan, the Department of Environment, Great Lakes, and Energy disperses the money to the health departments along state shores.

In Traverse City, the Watershed Center contracts specialists at SOS Analytical to gather samples and run the tests.

Testing at a few Lake Michigan beaches is privately financed.

Vacationers and locals alike are tempted to dive into the waves the day after a big storm. It’s only natural, after being cooped up inside for a day, to want to get straight back to enjoying summer fun.

But, equipped with the knowledge that E. coli could be lurking in the water, it makes sense to resist the urge to get wet the day after a downpour. It’s safer to stick to dry pursuits for 24 hours after the storm drains flush their contents into the lake.

If a health department hasn’t issued an E. coli-related recommendation by then, it’s probably safe to go back in the water.

— Traverse City Record-Eagle

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