SOUTH PORTLAND — Three years after the city passed an ordinance governing the use of pesticides, a set of companion regulations on the use of fertilizers is moving forward.

Councilors on Tuesday asked City Manager Scott Morelli to form an ad hoc committee to help draft an ordinance that would limit or ban the use of synthetic fertilizers.

The council also postponed a second vote on a proposed $7 million bond to fund a new Cash Corner fire station and repairs to other public safety buildings because there was insufficient public notice for the public hearing. The vote will happen Tuesday, April 16.

In a two-hour workshop April 9, councilors heard about the need to restrict the use of chemically manufactured fertilizers with compounds of phosphorus and nitrogen because of runoff and soil damage.

The workshop featured presentations from Jay Feldman, national director of Beyond Pesticides; Mary Cerullo, associate director of Friends of Casco Bay; Heather Spalding, deputy director of the Maine Organic Farmers and Gardeners Association; Curtis Bohlen, director of the Casco Bay Estuary Partnership, and Chip Osborne of Osborne Organics.

Councilor Maxine Beecher, who noted she is a beekeeper, said she is ready to move ahead on banning the use of synthetic fertilizers, although she expects there to be strong opposition.

“I am willing to take any crap that comes my way,” Beecher said as Mayor Claude Morgan polled the council on how to proceed.

The speakers detailed differences between synthetically produced fertilizers and organic ones, saying the runoff from water-soluble synthetic fertilizers can lead to algal blooms and impede the growth of eelgrass, an important part of the marine food chain.

“When we are talking about nutrients, we are usually talking about too much of a good thing,” Bohlen said, although he noted Casco Bay has not seen the kind of runoff damage sustained on Narragansett Bay in Rhode Island or Chesapeake Bay in Maryland and Virginia.

The speakers emphasized organic fertilizers and compost help build the soil structure, require smaller amounts, and are insoluble in water.

Osborne said an ordinance could at the least define when, how and where synthetic fertilizers are applied. While organic compounds, including compost, break down in the soil, he said synthetic fertilizers applied when the ground is still hard from frost are more likely to flow into waterways leading to Casco Bay.

Councilors envision an ordinance with a phased-in approach, which was the case with the pesticide ordinance that first affected municipal properties in 2017, private properties last year, and, on May 1, the city golf course.

Education would be emphasized, especially the benefits of organic alternatives. While the present pesticide ordinance does not carry fines for violators, Councilor Kate Lewis suggested stricter enforcement might be needed for both pesticide and fertilizer use.

In a 25-minute public hearing, speakers were largely in support of regulating fertilizer use, but Broadway Gardens owner Phil Roberts said a larger cause of runoff problems may be from ice-melting products. He asked if any testing had been done to determine the composition of runoff.

Fred Dillon, the city Stormwater Program coordinator, said that has not been researched.

Following Osborne’s caution that overuse of organic fertilizers can also damage soil, agronomist and city Pest Management Advisory Committee member Jesse O’Brien said the key is to ensure best land management practices for any fertilizers.

David Harry can be reached at 780-9092 or dharry@theforecaster.net. Follow him on Twitter: @DavidHarry8.