Truesdale Lake  

South Salem, New York

Lake Treatment Information

Due to the shallowness and large watershed of Truesdale Lake,  we must manage our lake to maintain its pristine appearance and excellent swimmability.

We use different combinations of treatments as recommended by our lake management company,  Allied Biological. Allied has been managing our lake for over 30 years. We comply with all DEC permitting requirements and notify affected homeowners in the winter or early spring about possible treatment chemicals. We typically apply for permits to use all three treatments below just in case they are needed. We don’t always use all three treatments in any given year however.

Below are links to the Product Labels and Material Safety Data Sheets (MSDS) for the treatments we have used in the past.

Aquathol-K is an aquatic herbicide used to treat weed growth throughout the lake. Application is usually once at the end of the spring (late May or early June).

Aquathol-K main page: http://www.cdms.net/LabelsMsds/LMDefault.aspx?pd=67&t=)

Copper Sulfate is used to keep algae blooms to a minimum during the summer. There are typically 4-5 applications during the summer.

Avast! or Sonar (same product, different name) is used only every few years to keep growth of weeds low. It is a longer-acting herbicide treatment than Aquathol-K but is more expensive. Treatment is typically once during a season with potential ‘bump’ treatment if conditions warrant.
When treatments are made to the lake,  Allied will post notices at the association beaches about water limitations. We will also post here on this website, on our Facebook page, and at the Nextdoor Truesdale site. (Sign up for Nextdoor Truesdale here if you are in the neighborhood — limited to deeded lake residents, addresses are verified).
Typically the restrictions on swimming are 24 hours and we don’t recommend watering your lawn with lake water treated by herbicides for at least a week. A summary of all restrictions is included with the notice posted on the day of treatment.