Algal blooms, which have become one of Casco Bay’s most challenging problems, are caused by excess nutrients – especially nitrogen – that flow into Portland Harbor and other densely populated coastal areas. Additionally, several South Portland streams and other water bodies do not meet water quality standards primarily due to the adverse effects of polluted storm water runoff from surrounding development.

City of South Portland Courtesy photo

To help address these concerns, the city council enacted a fertilizer ordinance that became effective in December 2020. The purpose of the ordinance is to protect our waterways while creating healthy, living soils that retain moisture and nutrients. It is also intended to prevent nutrient-laden runoff from the excess use and misapplication of fertilizers on lawns and turf.

The effort was an outgrowth of concerns raised by citizens that resulted in the creation of the pesticides ordinance in 2016. Pesticides and fertilizers are now regulated under a single Landcare Management Ordinance.

The process to develop the fertilizer ordinance started in June 2019 with the council appointment of a Fertilizer Working Group. The group consisted of stakeholders from a diversity of professional backgrounds who met on a monthly basis to carefully review information from fertilizer ordinances around the country, scientific studies and presentations from the Maine Cooperative Extension Service, among others.

The ordinance provisions that resulted from this process apply to all lawns and turf, whether public or private. The Sustainability Department and Landcare Management Advisory Committee are in the process of updating the city’s Grow Healthy South Portland website to provide an informative and user-friendly guide on how to comply with the new ordinance and use organic landcare practices.

In the meantime, a summary of the most relevant ordinance provisions for residents and businesses:

· Synthetic fertilizers are prohibited (except when waivers are granted).

· Organic fertilizer on established turf, including residential lawns is allowed only when a comprehensive soil test indicates a need for nitrogen. The fertilizer must be phosphorus-free unless the soil test indicates a need for phosphorus.

· Organic fertilizer on performance turf is allowed, but limited.

· Organic fertilizer for re-establishment of turf is allowed (with stipulations) and may contain phosphorus without a soil test.

For new development projects:

· Organic starter fertilizer containing phosphorus can be applied without a soil test.

· Topsoil must be 6 inches deep and contain 5 percent organic matter with a pH between 6.0 and 6.5.

· Compacted subsoil must be broken up to a depth of 10 inches (including the 6 inches of topsoil).

Over the next several weeks, the city will cover more topics associated with the new ordinance. Please check in periodically with the Grow Healthy South Portland website for more information or contact the Sustainability Department with any related questions.

Our Sustainable City is a recurring column in the Sentry intended to provide residents with news and information about sustainability initiatives in South Portland. The Sustainability Office is located on the first floor of city hall. Follow the Sustainability Office on Instagram and Facebook @soposustainability.

Fred Dillon is storm water program coordinator for South Portland. He can be reached at 767-7675, ext. 4138.

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