Your permit plan: Herbicide, algaecide or pond dye

Alum, enzymes and other additives

DEP

Alum or any other chemical used to control algae also needs the joint Chapter 91 permit. Enzyme products could be treated as chemicals under Chapter 91; DEP asks you to contact its Bureau of Clean Water about your product.

• DEP pesticide permitting FAQ, #23 and #24 (PDF)

Checked Oct 4, 2026 · Source: Water Quality Permitting for Pesticide Applications in Pennsylvania: FAQ (rev. Feb 21, 2025), FAQ #23 and #24 This may be outdated

Joint DEP/PFBC Chapter 91 permit (herbicides and algaecides)

DEP (for ponds and lakes, the application goes to DEP only)

Form: 3800-PM-BCW0094b

Fee: $250

Timing: Approval must arrive before any treatment; there is no minimum amount.

Before any herbicide, algaecide or fish-control chemical goes into surface water in Pennsylvania, including a private pond, you need a joint DEP/PFBC "Chapter 91" permit. There is no minimum amount: any use needs it, and use may not start until the approval arrives. Apply on form 3800-PM-BCW0094b, one application per site (a tax parcel or contiguous parcels, up to 20 water bodies). For ponds and lakes the application goes to DEP only, by upload or mail. DEP usually issues the permit to the person who owns or manages the property. Permits are typically issued without an expiration date; changing the water bodies, the product or a higher dose or more treatments needs a new application. Application fees: $250 new, $250 renewal, $100 amendment, $50 transfer; no annual fee.

What to have ready

• The pond's name and location, with a topographic map (pond circled and named) or its latitude and longitude.
• How the pond is used and which fish live in it.
• The pond's total area, the area you'll treat, and the average depth (try the pond size calculator).
• The plant or algae you want to control (see the plant guide).
• Each product's brand and manufacturer: Only products registered with the U.S. Environmental Protection Agency and with the Pennsylvania Department of Agriculture, and labeled specifically for aquatic use, can be listed on the Chapter 91 permit application.
• The dose and number of treatments per year, taken from the product label.
• A PNDI environmental review receipt: Include a PNDI environmental review receipt (PA Conservation Explorer) with the application.

• DEP: Apply for Pesticide Usage Permit
• PFBC: Algicide, herbicide or fish control chemicals
• DEP pesticide permitting FAQ (PDF)
• PA Conservation Explorer (PNDI review)
• Pond size calculator
• Weed and algae ID guide

Checked Oct 4, 2026 · Sources: Water Quality Permitting for Pesticide Applications in Pennsylvania: FAQ (rev. Feb 21, 2025), FAQ #14; Permit Requirement for Use of an Aquatic Herbicide in Ponds (updated Sep 8, 2025) This may be outdated