Algal Blooms Fed By Chemical Runoff And Climate Change, Study Says

Jon Hurdle | August 9, 2019 | Energy & Environment
Data compilation shows rising levels of unhealthy toxins in lakes and rivers around the country

Credit: NJ DEP
Algae bloom
Algal toxins fouling at least a dozen New Jersey lakes this summer are part of a growing national trend triggered by chemical runoff and the warmer temperatures and heavier rainfall that come with climate change, according to a new compilation of federal and state reports.

Environmental Working Group, a nonprofit that campaigns on water quality and other issues, released research on Thursday showing that the harmful compounds, known as cyanotoxins, were found in lakes, rivers and other water bodies at above an EPA health guidance level in more than 10,000 samples reported by state authorities around the country in 2018. Cyanotoxins include a subclass, microcystins, that can result in liver failure and cancer with long-term exposure.

Nearly all the samples were provided by a group of states that did not include New Jersey, a fact that drew the EWG’s criticism because recent data was not available for the Garden State.

Older data from the U.S. Environmental Protection Agency, based on tests in 2007 and 2012, found the toxins in water bodies in all 48 contiguous U.S. states, including New Jersey, and that the proportion of lakes where microcystins were found jumped to 39 percent in 2012 from 9.5 percent in 2007. The agency also tested for the toxins in 2017 but has not yet published those results.

More than two-thirds of Americans use water drawn from rivers or lakes, and suppliers are struggling to keep the toxins out of drinking water as runoff from farms and homes combines with warming water and bigger rainstorms to create conditions favoring formation of harmful algal blooms (HABs) such as those that have appeared in some New Jersey lakes this summer, EWG said.

Worries about swimmers, others

EPA has put microcystin and some other cyanotoxins on a list of candidates for regulation under the Safe Drinking Water Act but establishing enforceable health standards could take years, EWG said.

EPA said it’s working on a number of fronts to reduce the toxins in water bodies. It said it invited states to work with it and the U.S. Department of Agriculture to find ways of reducing runoff of “nutrients,” so called because they feed algal blooms. The agency is also offering webinars to educate the public on financing opportunities to improve water quality.

In June, the agency published recommended health standards to protect swimmers and other users of water bodies from the toxins.

“EPA’s research related to cyanotoxins and harmful algal blooms is focused in the areas of monitoring, analytical methods, health effects, remote sensing, water treatment and ecosystem impacts,” it said in a statement.

According to the EPA and the Centers for Disease Control and Prevention, the short-term health effects of exposure on microcystins include headaches, nausea and sore throat; long-term effects include tumor development, in addition to liver problems and cancer.

Impact on Lake Hopatcong

Those concerns led the New Jersey Department of Environmental Protection, starting in mid-June, to advise swimmers and boaters to avoid contact with the water in most of Lake Hopatcong, New Jersey’s largest, where the blooms containing the toxins have formed.

On Wednesday, the DEP lifted its advisory on a third area of the lake, Byram Cove, but urged the public to avoid activities such as water-skiing, tubing or kayaking that would bring them into contact with the water in the rest of the lake.

The state agency said there’s no recommended limitation on fishing or boating that wouldn’t involve contact with the water but it urged people not to eat fish caught there, and not to allow pets into the water.

The blue-green blooms have been found in 12 other lakes or reservoirs in New Jersey since May, and beaches have been closed on six of them, according to the DEP. New Jersey’s weather was unusually hot and wet in July, according to the state climatologist, David Robinson, who also said rainfall was among the 30 heaviest on record for the month.

EWG’s data compilation is shown on a national map that identifies 10 New Jersey sites where the EPA found microcystins. They include Orange Reservoir where the toxin was found at 0.4056 micrograms per liter in 2012, and Round Valley Reservoir where an average of 0.05 micrograms per liter was found in 2007. (A microgram is a millionth of a gram.)

The advisories are the result of an interagency strategy on HABs that has been reporting twice a week, according to DEP.

EWG said New Jersey should be doing more to monitor and advise on the issue, noting that it was not among the 14 states with public data for 2017 and 2018 that EWG used in its compilation.

“In comparison to states like Ohio, New Jersey could be doing more to inform the public about the existence of harmful cyanotoxins like microcystins in its public lakes,” said Soren Rundquist, EWG’s director of spatial analysis.

Harmful algal bloom detected at Manasquan Reservoir: Report by NJTV News