Bacteria to blame for turning Greenwood Lake green

BY Brenda Flanagan, Senior Correspondent |

Magnified bacteria glowed an ominous red under fluorescent light in a lab at Montclair State University.

It signals that the cell is alive, and that’s bad news for Greenwood Lake. The lake’s one of four in New Jersey where an HAB, or harmful algal bloom, prompted the state Department of Environmental Protection to post advisories against swimming this summer.

Students tested Greenwood’s water at 15 places on July 19 and counted bacteria cells per milliliter of water. Two of the sites were in the millions cells range, which is considered high-risk to use that water for recreation.

Experts say that contact with the algal bloom can lead to a high risk for rashes and diarrhea, and with long-term exposure could cause liver and nerve damage.

The other 13 Greenwood samples tested between 20,000 and 100,000 cells. Anything over 20,000 is considered moderate risk, according to the World Health Organization. That triggered the DEP swim advisory on Jersey’s side of the seven-mile-long lake, but not in the shallower eastern part, which is in New York.

Sen. Joseph Pennacchio says New York eyeballs the water and closes beaches if it looks bad, but New York tests for toxins produced by the bacteria before reopening. New Jersey’s 20,000-cell cutoff has meant weeks of HAB no-swim advisories at Greenwood, Lake Hopatcong and others.

“These numbers are based on extensive studies and analyses from a variety of organizations, including the World Health Organization,” said a spokesperson for DEP in a statement. “New Jersey uses levels that the state deems are protective of public health.” 

The state is retesting Greenwood Lake Wednesday. Meanwhile, residents are demanding the DEP take action and fix the problem. But it’s an issue with a long history involving money and politics.