You want to go to the beach. But you want to make sure the water is safe.
Cleveland’s popular Edgewater Beach had a few bad water quality days this summer — a harmful algal bloom during the July 4 holiday week and then a sewer discharge in August. So RocktheLake delved into water quality — how Northeast Ohio Regional Sewer District tests the water, and what the results mean.
The good news: The labs had similar E.coli findings, and none for harmful algal blooms.
The bad news: On Wednesday, Aug. 15, the day they tested, both CWM and NEORSD found E.coli levels above the U.S. EPA standard.
“It is over the level, but it is certainly not the highest that people have seen here recently,” said Lindsey Wittmer, director of quality assurance and quality control for CWM.
You can find water quality results for all Lake Erie beaches on the U.S. Geological Survey Nowcast website.
“We’ve very committed to providing the best public information we can, regarding water quality at the beach,” said Scott Broski, NEORSD superintendent of environmental services.
NEORSD works with the Cleveland Metroparks, which manage the beaches.
Let’s explain how it all works.
What do agencies test for?
NEORSD tests the Cleveland Metroparks beaches every morning about 6 a.m. for E.coli. The sewer district also checks for possible harmful algal blooms, though doesn’t run lab analysis unless workers see something suspicious.
Why is E.coli a bad thing?
E.coli is found in the gastrointestinal track of all mammals. High levels can cause nausea, diarrhea and other gastrointestinal issues in humans, especially children, senior citizens and people with compromised immune systems.
“It’s the same thing with certain kinds of food poisoning,” Wittmer said. “Some people may get sick and some people may not.”
How often is testing required?
The state requires popular beaches like Edgewater to be tested at least weekly. The sewer district tests daily. After Labor Day, it will test Monday through Thursday, until about October, when testing will cease for the season.
The sewer district has been doing daily testing for at least 25 years.
How does the testing work?
Lab analysts get a 100 mL sample of water. That’s about 4 ounces, or 1/3 of a pop can. The sewer district tests the water in its in-house laboratory, using an EPA-approved test called Colilert, which uses a chemical reagent in an incubator. Results take 24 hours.
CWM used a different test that is also EPA approved, m-ColiBlue, which also requires 24 hours. It collected five samples and combined them, and shared the sample with Enviroscience.
What were the results on Aug. 15?
CWM found 290 colony forming units of E.Coli per 100 mL.
That’s high. The EPA safe threshold is 235.
The sewer district results for the same day were 411.
“The variability from day to day is just absurd,” Wittmer said. “If it’s over 230, it’s not something you really want to swim in.”
Said Broski: “It really depends on the environmental conditions. It can change depending on a heavy rain storm, wind and waves.”
For example, that stormsewer overflow that closed Edgewater Beach after a big rainstorm in early August? The E.coli levels were more than 2,200. But goose and gull poop and fish also play a roll.
So what do the results mean?
Though the water was above EPA standards on Aug. 15, no one knew it because test results take 24 hours.
To decide whether a beach is safe for swimming that day, the sewer district instead uses a predictive model, based on wave height, Ph balance, turbidity, 24-hour rainfall and more. Generally, the drier the weather, the lower the E.coli. That’s because contaminants can flow into the lake when it rains.
But it’s like predicting the weather. Sometimes the forecast is wrong, unfortunately.
The sewer district model predicted good water quality on Aug.15. The water quality websites showed no advisories.
Only later can the sewer district research what might have caused the high levels of E.coli and compile it with a huge quantity of data — what it got right and wrong — to fine-tune its predictions for the future.
What about harmful algal blooms?
Harmful algal blooms, thankfully, are rare in Cleveland.
Stow-based Enviroscience tested for four toxins that can be present in harmful algal blooms, with an ELISA test that uses colored enzymes to bind to toxins. All of the toxins were below detection levels, said laboratory technical supervisor Kate Hansler
- Anatoxin-a, a neurotoxin that affects the brain
- Microcystin, a liver toxin, that promotes tumor growth
- Saxitoxin, a paralytic shellfish poison that causes progressive muscular paralysis
- Cylindrospermopsin, a liver toxin
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