When Toledo’s internal water sample testing revealed potentially dangerous levels of microcystin, the city issued the ban on drinking it, and notified the state’s Environmental Protection Agency. Then the city and the EPA began sending out a series of water samples to five different labs, all with different testing procedures.
"Some of the test methods were showing that there was nothing in the water. Some of the test methods were showing that there was a level above the World Health Organization recommended limit for drinking water," said Brenda Snyder, chief chemist for Toledo’s Water Division. She said city officials made the right decision by erring on the side of public health throughout the crisis.
Snyder said testing for microcystin has only recently moved out of the most sophisticated research labs and into those of municipal water systems like Toledo’s. Over the past 10 years, testing has gotten better, with results available in hours, rather than days. But, "The scientific community does not yet have an easy, simple, easily verifiable, robust test."
The way water samples are processed, the equipment that’s used and how the operator is trained can all impact results, Snyder said.
That poses problems for decision-makers in a crisis. In Toledo, they cast the broadest net possible, then went with the most conservative course of action. And during that flurry of activity, the local, state and federal officials involved – all with different views on which testing methods were best – sat down and hashed out a way forward.
That written protocol for how testing would be conducted is now in the hands of every public water system in Ohio, "so that everybody is doing it consistently," said Craig Butler, head of Ohio EPA. He said the method everyone ultimately agreed on was the one least likely to give a false negative result – to say toxin levels are lower than they really are.
Snyder said it’s the same test that had been showing unsafe levels of toxins when other tests weren’t.
She said all the current testing methods are imperfect. And as algae blooms become more of a threat to drinking water, there’s an urgent need to improve them.
No one knows exactly what the toxin levels were in Toledo. But "I plan on keeping some of the samples that we pulled from this weekend in a freezer," Snyder said. She hopes one day, with better testing, there will be an answer.
Meanwhile, officials who struggled with the testing confusion are pushing the federal government for guidance. There’s no national standard on safe levels of microcystin. In Toledo, officials used the World Health Organization’s 1 part per billion recommended maximum.
The U.S. EPA has said it will release its own recommended limit late this year or early next year. But state EPA chief Craig Butler said it’s needed sooner.
"I’ve talked to the national administrator of EPA and her senior staff in the last couple of days, saying, ‘I know you’re working on this, but this is a clear example of why we need to accelerate that research,'" he said.
Officials now seem to agree on the best methodology for testing for microcystin, Butler said. Now they need a firm consensus on how much is safe.