October 02, 2025| Community, Environment
By: Holly Odgers
Water treatments will continue next week as part of the ongoing pilot project to reduce harmful algal blooms (HABs) in shallow, near-shore areas. These efforts are being led by Princeton Hydro in partnership with the Lake Hopatcong Foundation, Lake Hopatcong Commission, and the New Jersey Department of Environmental Protection (NJDEP), with funding from the U.S. Army Corps of Engineers.
Two late summer treatments were completed in September in the northern area of Woodport and Landing Channel.
Starting around Tuesday, October 7, boats will be working in Van Every Cove, applying a treatment designed to improve water quality by reducing the nutrients that fuel algae growth (see treatment details below). These algae overgrowths, called harmful algal blooms (HABs), can affect water quality and make the lake unsafe for people, pets, and wildlife. The treatment is expected to take a few days.
Sometime in mid-October, crews will move to Great Cove for approximately a week. Equipment and boats for these final two treatments will be staged at Lee’s County Park Marina, so you may also notice activity there.
There are no temporary use restrictions for the Van Every Cove and Great Cove treatments; however, Princeton Hydro recommends not drawing water from the lake within the treatment zone within 24 hours of treatment, out of an abundance of caution, and to ensure a successful and even application.
All products are commonly used as water clarifiers and have been approved by NJDEP. Signs will be posted in the treatment areas.
You can read more about the pilot program at Exploring Solutions to Combat Algal Blooms on Lake Hopatcong’s Shorelines
For Van Every Cove, a “kill and sink” treatment strategy will be conducted over a treatment area of 23 acres. The kill component will use the oxidizer algaecide GreenClean 5.0, followed by the sink component, which will be EutroSORB G. It is anticipated that the treatment will take 2 - 3 days. There are no temporary use restrictions during or after treatment; however, it is recommended by Princeton Hydro not to draw water from the lake within the treatment zone within 24 hours of treatment, out of an abundance of caution, and to ensure a successful and even application. Signs will be posted in the treatment area.
For Great Cove, a “kill, floc, and sink” treatment strategy will be conducted over a treatment area of 44 acres. The kill component will use the oxidizer algaecide GreenClean 5.0, followed by the floc component, which will use the coagulant LiquiFloc 1% (active ingredient chitosan), and the sink component, which will be EutroSORB G. It is anticipated that this treatment will take 6 - 8 days. There are no temporary use restrictions during or after treatment; however, it is recommended by Princeton Hydro not to draw water from the lake within the treatment zone within 24 hours of treatment, out of an abundance of caution, and to ensure a successful and even application. Signs will be posted in the treatment area.
Ready Scout, LLC will be conducting the GreenClean 5.0 applications, and Princeton Hydro will apply all other products.
