What Will Help Rid NJ Lakes of Algae? State Says Cut Flow of Nutrients

DEP seeks long-term fix for blooms that can be harmful to swimmers, boaters
Credit: (AP Photo/Lisa Rathke)
File photo: Algal bloom

As the number of New Jersey lakes clogged by harmful algal blooms rises for the second summer running, state officials said the most important long-term solution to the problem is to reduce the flow of nutrients from sources including suburban lawns and farm fields into waterways and lakes.

Although the Department of Environmental Protection is trying a series of short-term treatments, officials said it is more likely to find a long-term fix by persuading residents and farmers to use less fertilizer in order to cut the flow of phosphorus, a leading cause of the slimy green blooms, known as HABs, officials said. The blooms make some lakes dangerous to the health of swimmers, anglers and pets.

Bruce Friedman, director of water monitoring and standards at the DEP, said that measures such as green infrastructure — the creation or preservation of surfaces that allow rainfall to soak naturally into the ground rather than becoming contaminant-laden runoff — are needed if heavily used water bodies such as Lake Hopatcong are to avoid the blooms in future.

“Those are really the types of technologies that we want to invest in because they are long-term solutions to what the real problem is, which is nonpoint source pollution, and runoff from impervious surfaces,” Friedman said during an online news conference on the status of the problem. Nonpoint pollution comes from general runoff, as opposed to point-source pollution that comes from specific sources like industry or water-treatment plants.

The blooms are being fed by nutrient-contaminated runoff and leaking septic systems in water that’s warmed by climate change. While New Jersey alone can’t control the warming climate, it has the potential to curb phosphorus-laden flows into its waterways.

‘Visible symptom of global warming’

Still, the blooms are a vivid reminder that a warming climate is affecting everyday life now, said Kati Angerone, an associate commissioner at the DEP. “It’s a real and visible symptom of global warming,” she said.

Treatment techniques include aeration, harvesting of aquatic weed, the construction of wetlands platforms, and even the use of ultrasonic waves, but all are short-term solutions for symptoms rather than an attempt to prevent the root causes of the problem, Friedman said.

“If I have algae in my pool, I throw a bunch of copper sulfate in there and it usually clears it up,” he said. “But a lake isn’t a pool, especially in New Jersey. These are our treasures. These are ecosystems that need to be managed in a way that’s healthy, and not just clear for swimming.”

Last summer, more than 30 lakes were affected by the blooms, DEP officials said.

There are 16 confirmed blooms so far this year, slightly more than the 12 that were confirmed by the same point of 2019.

The similarity between the two seasons may reflect this year’s relatively dry summer, which — despite the recent Tropical Storm Isaias – has seen fewer of the heavy downpours that feed the blooms than occurred last year, officials said.

Spreading to South Jersey

But the problem seems to be spreading from north Jersey, which saw most of last year’s blooms, to now include South Jersey, with reports of blooms in Burlington, Gloucester and Camden counties, officials said.

They highlighted a new interactive mapping tool that shows the locations of HABs, and ranks them with a color-coded system by order of severity. So far this year, two water bodies — Driscoll Pond and Hopkins Pond, both at Haddonfield in Camden County — have been given a “warning” designation, the second-highest of five levels, indicating that public bathing beaches are closed because of a “high risk of adverse health effects” due to high levels of microcystins, the toxins produced by algae. Another 20 locations have an “advisory” designation, meaning that toxin levels are lower but beaches are still closed.

Officials noted that the existence of a bloom on a lake doesn’t necessarily mean the whole lake is off limits for activities like swimming and boating, and will just apply to specific parts of the lake.

Jeff Tittel, director of the New Jersey Sierra Club, said reducing nutrient flow into lakes can only be achieved through the renewal of water-quality regulations that were weakened during the Christie administration.

“DEP needs to go back and fix rules on stormwater and stormwater runoff that Christie weakened, and bring back the watershed protection programs that we had in the 90s,” he said. “We have to put the lakes on a pollution diet.”

DEP’s Friedman said runoff can be reduced by curbing development, which has a proven link to the ecological health of lakes and streams.

“We know there is a correlation between the amount of development and impervious surface of a watershed, and aquatic health,” he said. “We really need to identify the source of pollutants, and not just continue to try to treat, through algicides, and aeration, and any of these technologies. They’re short term, while we address the longer-term problem.”