Lawns Are to Blame for Much of the Nitrogen and Toxic Chemicals in the Bay

Posted on Apr 28, 2015

Joe’s footprints in green slime at a cove in Falmouth

Joe’s footprints in green slime at a cove in Falmouth

Casco Baykeeper Joe Payne received a panicked call from a member of Friends of Casco Bay who lived on a cove in Falmouth. He asked Joe to discover the polluter whose actions had turned his scenic inlet bright green. When Joe walked out onto the flat to investigate, his boots sank four inches into green slime. He observed that the member had recently installed a culvert under the driveway that channelled rainwater runoff directly into the cove. He turned to his worried friend and said, “You did this.” The culvert was collecting runoff from fertilized yards in the neighborhood, stimulating a lush growth of green algae across the entire cove.

Friends of Casco Bay’s stormwater monitoring reveals that this neighborhood is not the only one over-fertilizing the Bay. We have found nitrogen and lawn care pesticides in waters around Casco Bay.

When Friends of Casco Bay tested stormwater for pesticides in a South Portland waterfront neighborhood, we found Diazinon and 2,4D, a component of weed and feed products. This prompted further testing at every coastal community around Casco Bay. We detected more pesticides flowing into the Bay in stormwater. Our findings inspired our BayScaping program, which teaches residents how to reduce their use of lawn chemicals.

Pesticides and fertilizers can harm marine life, as well as children and pets. But the good news is there are simple ways you can grow a green lawn that keeps Casco Bay blue.

BayScaping will save you time, save you money, save your lawn, and save the Bay! Join your neighbors, and learn more at cascobay.org/bayscaping.

Because our advocacy is grounded in science, we worked in conjunction with the Maine Board of Pesticides Control to collected water samples around Casco Bay. Chemicals we found are shown on this map.

Read the next section of the report What Is Our Coastal Future?