Algae bloom hits Greenwood Lake, prompting advisory against swimming and water sports

An algae bloom has prompted an advisory against any contact with water at Greenwood Lake in West Milford, including swimming, wading and water sports, local officials said Tuesday. 

It is the second major lake in North Jersey to be stricken with harmful levels of cyanobacteria, following Lake Hopatcong in Morris and Sussex counties, where a no-swimming advisory has been in effect for three weeks. 

“We’re warning people to be cautious and to use their best judgment," said Paul Zarrillo, the New Jersey chairman of the Greenwood Lake Commission.  "Try not to go in the water. Don’t drink it."

Signs were posted Tuesday at Brown’s Point Park and the Greenwood Lake Dam warning people against going into the water due to cyanobacteria levels "quantified at or above the NJ Health Advisory Guidance.”

Three beaches were closed by the West Milford Health Department, Zarrillo said. 

Story continues below gallery

A spokesman for the Department of Environmental Protection did not immediately return a request for comment Tuesday evening.

The DEP listed Greenwood Lake on its webpage of cyanobacteria outbreaks Wednesday and said the bloom was first reported July 12.

The bloom comes at the busiest season for the lake, which stretches for seven miles from West Milford into Orange County, New York, and is managed by a bi-state commission.

New York environmental officials said late Tuesday they are investigating whether the algae bloom extends into their side of the lake.

Jesse Dwyer, mayor of the Village of Greenwood Lake in New York, said in a Facebook post Tuesday that water samples taken in his community show "algae levels DO NOT meet the threshold of concern."

But the findings in West Milford are concerning to local officials.

“I’m concerned about our marinas and local businesses," West Milford Mayor Michele Dale said Tuesday. "It’s the middle of the season for them. It’s not good."

Testing is ongoing but the lake remains open for boating, Zarrillo said.

Other activities such as jet skiing and swimming should be avoided, he said.

'RAIN TAX':Lake Hopatcong's toxic algae bloom renews fight over stormwater law derided as 'rain tax'

AFFIDAVIT:Newark cop 'blacked out' when he saw man in estranged wife's room. Then he started shooting

Fish caught in the lake should not be eaten, the advisory states. Pets should not drink the water.

Dale said the state planned to conduct an aerial survey of the lake on Wednesday.

High levels of the bacteria have been detected in recent years in Greenwood Lake, but not enough to prompt an advisory, said Meiyin Wu, a Montclair State University biologist who has taken samples from the lake for the past few years.

"I'm not surprised at all," Wu said Tuesday of the elevated levels. "We have been seeing higher levels over the past few years. And now you have the perfect conditions for an algae bloom."

So far this year the harmful blooms have also hit Deal and Sunset lakes in Monmouth County, and Swartswood Lake and Lake Mohawk in Sussex County. The problem has also cropped up in lakes in New York and Pennsylvania.

This summer's weather patterns of intense but short rainstorms followed by several hot, sun-filled days have created the perfect conditions for the blooms to occur, experts say.  

The storms sweep nutrients — mainly phosphorous from fertilizer — into lakes where it acts as a food source for the algae to feed on. The blue-green algae, or cyanobacteria, prefer three conditions to bloom — warmer water, still water and elevated nutrient concentrations.

In late June, the DEP investigated a reported algae bloom at Belcher's Creek, which flows into Greenwood Lake, but determined there was no cyanobacteria present.

The creek is the source of 30 to 50 percent of Greenwood Lake's pollutants, including nutrients.

 A spokeswoman for the New York Department of Environmental Conservation said her agency will be investigating cyanobacteria levels in the New York side of the Greenwood Lake.