Aquatic herbicide application. Photo: Bryan Swistock, Penn State University
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. The permit application requires the following information:
- Name and location of the water body, including a topographic map or latitude and longitude of the pond
- Specific uses of the water body
- Types of fish present in the water body
- Total area of the water body and the size of the area to be treated
- Average depth of the water body
- Name of plant to be controlled
- Commercial and manufacturer's name of the chemical to be applied (Note: Only herbicides that are registered with the U.S. Environmental Protection Agency, registered with the Pennsylvania Department of Agriculture, and labeled specifically for aquatic use can be listed on the permit application.)
- Name of each chemical to be applied
- Number of treatments to be made throughout the year.
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.
The permit can be obtained from local PA Fish & Boat Commission or Department of Environmental Protection office or online