LANSING, MI — As this summer’s harmful algae bloom in Lake Erie grows in toxicity, Michigan environmental regulators are still reviewing whether to add the state’s portion of the lake to a list of impaired waters that was supposed to be in the U.S. Environmental Protection Agency’s hands this spring.
The Michigan Department of Environmental Quality said it’s in “discussions with both internal and external partners” about the designation for Western Lake Erie, which has inevitably turned green again thanks to rampant algae growth.
Environmental groups are pushing for the “impaired” designation, which would trigger more stringent pollution controls under the federal Clean Water Act.
The biennial report was due April 1.
“The Clean Water Act provides powerful tools to protect our drinking water, public health and economy,” said Joel Brammeier, CEO of the Chicago-based nonprofit Alliance for the Great Lakes.” It’s time to use them.
Scientists say this year’s harmful algal bloom is more toxic than the record-setting bloom in 2015, although the current bloom is smaller in size.
Tim Davis, a biologist with the Great Lakes Environmental Research Laboratory in Ann Arbor, said the color and thickness of algae scum areas in the west end of the lake varies between “limeade and Sherwin Williams paint.”
Concentrations of microcystin, a toxin inside the blue-green algae, are highest in Maumee Bay and the mouth of the Maumee River in Toledo, Davis said. Those are also where the thickest algae scums are located.
Sampling there has found microcystin at levels around 50 parts-per-billion, well above Ohio’s dual public health advisory levels. At 6 ppb, children, pets, pregnant or nursing women and those with medical conditions should avoid touching the water. At 20 ppb, algal toxins are considered unsafe for anyone.
Ohio also has dual drinking water regulatory limits of 1.6 ppb for adults and 0.3 ppb for women and children in finished, treated water.
“These concentration are well above the drinking water guidelines, but obviously no one is scooping up raw lake water and drinking it,” said Davis. Few are swimming in scummy green water, as well.
“Where we’re seeing these elevated concentrations is also nowhere near the municipal intakes.”
Along Michigan’s shoreline, Davis said weekly sampling shows relatively low concentrations of microcystin off Monroe, but wind and waves can change that.
Both this and last summer, “we’ve seen toxin concentrations at our Monroe site that have exceeded Ohio’s current recreational advisory levels.”
The National Oceanic & Atmospheric Administration (NOAA) has been sending out weekly bulletins on the bloom status since early July. Thus far, the bloom is following the forecasted pattern — mild to moderate severity thanks to a drier spring that cut down nutrient runoff into Lake Erie tributaries.
Blooms typically peak in size and toxicity in August and end by late October.
“It definitely has not been nearly as bad as the record-setting bloom in 2015 and the second-largest bloom in 2011,” said Davis. “What we’re seeing right now is what we anticipated in terms of size, but this year’s bloom is much more toxic.”
Why? Well, that’s still not fully understood. Scientists are studying how nitrogen and light interact to boost algal toxins, but Davis said its still unknown what role nitrogen plays in toxicity. Like phosphorus (which fuels bloom size), nitrogen (which fuels bloom toxicity) is found in both urban and agricultural runoff.
Microcystin needs a lot of nitrogen to grow, Davis said.
Microcystin can cause rashes, nausea, headaches and even liver and kidney damage. Unfortunately, bloom toxicity forecasts aren’t yet possible.
In January, Michigan released a plan to reduce nutrients entering Lake Erie that leans heavily on maintaining discharge reductions at Detroit area sewage plants through tighter pollution permits. The plan hasn’t wowed environmental groups, who want to see the state do more to curb farm runoff.
Last summer, Michigan, Ohio and Ontario in Canada signed a joint pledge to reduce phosphorus hitting Lake Erie by 40 percent over the next decade and by 20 percent over the next five years. In the wake of Toledo’s 2014 crisis, Ohio put limits on when and where farmers can spread fertilizer and manure on fields.
Much of the phosphorus comes from Lake Huron through the St. Clair and Detroit River systems. Roughly 80 percent of the water and 40 to 50 percent of the phosphorus entering Western Lake Erie comes through the Detroit River.
Under the Clean Water Act, states must set and enforce limits called Total Maximum Daily Loads (TMDLs) on pollutants discharged into rivers, lakes and streams to protect drinking water and recreational uses.
Heidi Grether, the new DEQ director, has the final say on which waters are included on the impaired list sent to the EPA. Federal regulators will get the list “soon,” according to a DEQ statement this week.
“The Michigan Department of Environmental Quality agrees the situation in Lake Erie is a serious environmental and public health concern. The department is fully committed to resolving the problem as evidenced by its action to reduce phosphorous loadings in Lake Erie, active involvement in the Collaborative Agreement signed by Governor Snyder and the Annex 4 process. We are currently in the process of reviewing available information, including discussions with both internal and external partners about listing the WLEB (Western Lake Erie Basin) as impaired waters in response to compelling public comments submitted on our draft list. The final impaired waters list is expected be submitted to U.S. EPA soon and we will update when that occurs.”
The EPA considers a water body “impaired” if any one of its uses, such as for drinking or recreation, does not meet regulatory standards for water quality.
Michigan standards for nutrient pollution stipulate “nutrients shall be limited to the extent necessary to prevent stimulation of growths of aquatic rooted, attached, suspended, and floating plants, fungi, or bacteria, which are or may become injurious to the designated uses of the surface waters of the state.”
According to the EPA, a 2005 TDML was developed for nitrogen pollution in the River Raisin, a Lake Erie tributary in Michigan. Other phosphorus TMDLs have been developed for drains that feed into Lake Erie because of algal growth.
Most of the state’s TMDLs address E.coli bacterial contamination at beaches and polychlorinated biphenyls (PCB) contamination from old industrial pollution.
Michigan controls 115 square miles of Lake Erie and 7 percent of the basin.