Reducing Stormwater Pollution

The Problem with Stormwater
Childhood rhymes teach us that spring rains are cleansing showers that bring May flowers. Unfortunately, heavy rains are not benign. Stormwater runoff is the leading source of water pollution to the nation’s rivers, lakes and coastal waters. It may contain oil, gas, heavy metals, de-icers, pesticides, fine sediments, fertilizers, and bacteria. During Maine’s mud season, stormwater often takes the form of snowmelt, which delivers a toxic shock of winter’s accumulated wastes to coastal waters after the first thaw.

Research Associate Mike Doan collects a stormwater sample in Cape Elizabeth.

Friends of Casco Bay’s research shows that stormwater is not a theoretical threat to the Bay. In developing the basis for our initial stormwater plan, we sampled 19 sites from Cape Elizabeth to Harpswell, and found six toxic pesticides in our waters:

(Click here to see the map)

 2, 4-D: banned in five countries, this herbicide is toxic to aquatic invertebrates and has the potential to harm birds.
 Clopyralid: this herbicide has been linked to birth defects in animals.
 Diazinon: recently banned from being sold to U.S. consumers (but still legal for use), this insecticide has been linked to human reproductive problems and has a high acute aquatic toxicity.
 Dicamba: found in surface and groundwater throughout the U.S., this herbicide is toxic to fish and zooplankton.
 MCPP: along with 2, 4-D, this herbicide is in the same family of chemicals as Agent Orange and is highly toxic to bay shrimp.
 Propiconazole: this fungicide is a possible carcinogen.

Solving the Stormwater Problem
Friends of Casco Bay is taking a comprehensive approach to reducing stormwater pollution.

Our Water Quality Monitoring Program is collecting stormwater samples to monitor the problem. We are also developing a first-in-the-nation volunteer stormwater monitoring pilot project. For this pilot project, we are writing a modular Quality Assurance Project Plan (QAPP) to make the data we collect scientifically defendable. The modular QAPP will also be available for organizations across the country, so others can learn from our experience.

We are also working with our community to reduce the pollutants in stormwater. For example, our BayScaping program is spreading a grassroots ethic for ecological lawn care, teaching residents and businesses how to grow green lawns that keep Casco Bay blue.