Overall, the Libby River appears to be healthy. Former land uses such as gravel mining and junk yards, which once contributed to a decline in water quality and habitat, have ceased operation. However, old land uses are being replaced by new land uses with a new set of problems. As a watershed becomes developed, the portion of rainfall (i.e., stormwater) and snowmelt that seeps into the ground diminishes and the amount that flows into streams from road ditches and storm sewers increases, yielding polluted runoff. Polluted runoff can ultimately harm water quality in the Libby River and the Scarborough Marsh.

Polluted runoff can contain a variety of pollutants, including:

• nutrient overdose of nitrogen and phosphorous
• sediment from soil erosion
• bacteria
• toxic substances such as pesticides, herbicides, petroleum products, and metals

Presently, the only pollutant that is being monitored in the Libby River is bacteria. The Maine Department of Marine Resources tests for bacteria in order to determine whether clam flats are safe for harvesting. While urban wildlife and failing septic systems can be a major source of bacteria in polluted runoff, one of the largest sources is pet waste that enters storm sewer systems. The good news is that the last ten years of Libby River testing indicate decreasing levels of bacteria. The bad news is that clam flats in certain areas of the Libby River are still subject to automatic closure after large storms because of high bacteria levels.

Problems identified during the watershed survey generally fall within the following four categories:

The cumulative effect from actions that private landowners can take on their property will likely yield the biggest benefit to the Libby River and the Scarborough Marsh. In terms of the problems that were identified during the watershed survey, the private landowner has the greatest control over the problems listed under the categories of Landowner Practices and Vegetated Buffers. A few possible solutions to the problems listed under those categories are listed below.

• Determine if there are stormwater control structures in your neighborhood. Contact the Town for information on their location.

• If there are stormwater control devices in your neighborhood, determine which organization is responsible for their repair and maintenance. Check with that organization to be sure that the structures are regularly inspected and maintained or repaired, as required.

• If there are no stormwater control structures in your neighborhood, determine the feasibility of installing control structures or other pollutant removal devices or systems. Contact the Town about possible options.

• Be an advocate in your community for the development and implementation of a stormwater master plan that addresses the cumulative effects of stormwater runoff from existing and future development in your watershed.

• Support the Friends of Scarborough Marsh and other local conservation organizations that have pledged to conserve, protect, restore, and enhance the Scarborough Marsh Watershed.

If you are interested in learning more about the Libby River Watershed Survey, a report has been prepared that presents the survey findings and the results of related evaluations in greater detail. For a copy of the report, or questions about the survey or other conservation activities sponsored by the Friends of the Scarborough Marsh, please contact: