East Lyme — More than two months after mud slid into wetlands and a tributary of Cranberry Meadow Brook during a rainstorm, the town is asking developers of a solar farm on the site to do more to stabilize the property.

The Inland Wetlands Agency voted Monday to re-issue a cease-and-correct order against the developers.

The order carries new requirements, including hydro-seeding all exposed soil areas, installing check dams around the site's border and putting up additional measures in anticipation of storms, such as hay bales, and more inspections.

The developers of the solar farm on Walnut Hill and Grassy Hill roads are to restore the site by Sept. 30. After a heavy rainstorm in late March led to the silting of wetlands and watercourses, the town issued its first cease-and-desist order against Greenskies Renewable Energy and Centerplan Construction Co. During the late-March storm, stormwater basins failed or overflowed.

Since then, the companies had taken emergency measures to stabilize the site and hired a biologist to review downstream damage and a civil engineer to propose corrective actions, Centerplan Construction CEO Robert Landino said in a phone interview Monday. The developers also submitted an engineering plan to the commission.

But at least two subsequent rainstorms have brought more concerns about turbid water running off the site. Wetlands Enforcement Officer Gary Goeschel, who inspected the site during a rainstorm last Thursday, said a large volume of water carried sand and silt deposits into the unnamed tributary of Cranberry Meadow Brook. Photos from the inspection show water high up against silt fences and muddy areas.

Monday's show-cause hearing covered many technical aspects of stormwater management. In some cases, commission and the developers' representatives debated aspects of the plan.

The developers' environmental consultant, along with Goeschel, surveyed downstream of the field last month and found 22 small deposits of silting in the tributary. There was also deposits in Cranberry Meadow Brook but the consultant said it could not be determined if they were from the site.

Chairwoman Cheryl Lozanov raised questions about the use of polymers to separate dirt from the stormwater. She said she was concerned the materials could be harmful to sea life and eventually humans if they flowed from the farm into Long Island Sound. In the end, the developers and the town will continue to research it, and Goeschel will have the authority to decide on whether or not to use it.

The commission also asked the developers to install erosion control measures below the solar panels' edges. Centerplan President Michael Lombardi said once the grass seed grew in, the site would no longer be vulnerable to storms, but agreed to discuss it with the developers' engineers and bring more information to the commission.

Lozanov said that the water run-off could muddy the grass and reduce its effect. She also stressed that the developers are planning on using the site for more than 25 years.

"What we do now is going to protect the site for that time," she said.

The developers will present more information at the commission's next meeting in July, and there will also be a site walk of the area. While some of the developers' remediation plans call for vacuum-removal of silting during the drier, summer months, they also said they are already employing ways to mitigate storm run-off, such as cleaning out the catch basins so mud doesn't accumulate.

The town will also submit its list of requirements to the Connecticut Siting Council, which has jurisdiction over placing projects, such as cell towers or in this case solar farms, in communities. The council will then also issue the requirements to the developers, according to an email from the council's acting executive director, Melanie Bachman, which was read aloud at the meeting.

Bachman said in a phone interview last week that the plan for the solar farm called for exposed soil areas to be sown with seed mixes after construction. She said it was a matter of "bad timing" that the seed mixes planted by the developers hadn't had a chance to grow in before the first rainstorm in March.

k.drelich@theday.com