An aquatic herbicide being applied with a backpack sprayer.
Over half of Pennsylvania pond owners indicate that nuisance algae and aquatic plants are a problem for their pond. Penn State surveys have found that about 40% of pond owners with nuisance algae and plants have used aquatic herbicides to control the growth. However, 65% of these pond owners were unaware that a state permit is necessary before making any herbicide application to a private pond or lake. The permit, officially known as the Application and Permit for Use of an Algaecide, Herbicide, or Fish Control Chemical in Waters of the Commonwealth, is a simple, two-page permit that is jointly reviewed by the Pennsylvania Fish and Boat Commission (PFBC) and the Pennsylvania Department of Environmental Protection (DEP). The permit must be submitted and approved by both agencies before the herbicide is used.
Effects of the chemical in and downstream from the pond are considered in the approval process. The permit may be denied or limited if the pond overflows into a stream where downstream aquatic life may be affected. In an impoundment with a wet weather discharge, avoid problems by treating when little or no overflow is occurring. Keep in mind that herbicides are more likely to be effective in ponds with little or no outflow where the chemical stays in the water for a longer period of time.