top of page

Plan To Add Oxygenation System to Lake Hopatcong Presented at Public Meeting

ROXBURY – A plan to potentially add an oxygenation system to the efforts to clean up Lake Hopatcong was explained at a public in-person and online meeting on November 2.

Morris County, the Lake Hopatcong Commission and the Lake Hopatcong Foundation hosted a meeting at the Roxbury Township Municipal building at which Fred Lubnow and Pat Rose, scientists from Princeton Hydro LLC, the lake environmental consultant, outlined the plan. Lubnow said the goal of the proposed project would be to add oxygen directly to the 987-acre dead spot at the bottom of the middle of Lake Hopatcong. A specific location for the system has yet to be determined.

In 2019, this area of the lake added to the creation and long-length of a Harmful Alga Bloom (HAB) that essentially closed the lake for the summer season.

The area is called anoxic, meaning there is no oxygen in the water at that level of the lake.

Lubnow said in 2019 when the significant HAB occurred, the lake weather had periods of heavy rain followed by high temperatures. As a result, high levels of phosphorus washed into the lake, the chief pollutant in the 2,600-acre body of water.

Cyanobacteria, the chief culprit of the HAB, thrive in warmer, stagnant water and feed on the polluted waters. The addition of oxygen to the anoxic portion of the lake bottom will help bind the phosphorus in the water to iron, in essence removing phosphorus as a food source for the cyanobacteria.

Lubnow said the goal is to maintain a daily level for phosphorus of .03mg/ml, a standard measure agreed upon decades ago by lake officials and state and federal governments.

In June 2019, he said, for the first time after many years of steady decline, the average daily level of phosphorus in Lake Hopatcong topped .04mg/ml, fueling the HAB.

The oxygenation system would consist of oxygen generators placed on the shore of the lake, a system of pipes to carry the oxygen to the lake bottom and an exchanger-devise that would mix the oxygen with the anoxic water, creating a higher level of dissolved oxygen in the turbid water, Lubnow said.

This system is similar in theory to the aeration system installed in 2020 in Hopatcong’s Crescent Cove, Lubnow said. The difference is that the aeration system in Crescent Cove adds oxygen to the water as it stirs the entire water column, and the oxygenation system proposed, injects oxygen into the bottom layer of the water.

This oxygenation system is very different the three nano-bubble aeration projects that were installed in the spring at beaches in Mount Arlington, Lake Forest Yacht Club in Jefferson and Shore Hills Country Club in Roxbury, he said.

The new system could have up to four oxygen generators, Lubnow said. The concept is under development. An early cost estimate for the system runs between $1.5 and $2.5 million, Lubnow said. It could cost $100,000 annually to provide electricity to the system.

A more exact cost and design will be presented at a follow-up meeting in the spring, with no date announced.

Lubnow said while the state Department of Environmental Protection has offered support for the development of a concept plan, the department would not be funding the installation or operation of the system.

Colleen Lyons, administrator of the Lake Hopatcong Commission and Kyle Richter, executive director of the Lake Hopatcong Foundation, both said grants would be sought to install and operate the new system if approved.


bottom of page