Plans to create a 4-acre solar array in Portland are forcing city officials to address longstanding issues at its closed landfill off Ocean Avenue.

The city is looking to install more than 2,800 solar panels on the closed landfill by the end of the year so it can take advantage of higher rates paid for electricity from solar projects. Changes to so-called net metering rules will begin ratcheting down rates for solar energy beginning next year.

But before it can install the solar panels, the city must fix the landfill cover, which has settled over the years and been compromised by recreational use, lack of maintenance and erosion. The city must also install vents to address methane gas that is collecting underneath the landfill cover.

Several landfill neighbors, including Copley Woods Circle residents Sara Scola and Kim Rich, have been showing up at City Council meetings to urge the city to fully address the issue. They have expressed concern that the city would rush the mitigation work because of the solar project.

Last Monday, they reiterated their concerns during a public comment period.

“This site has been neglected. The maintenance plan has not been implemented,” said Scola, who has been following the issue since 2008. She noted that the city hasn’t maintained fences to keep pets and people out of contaminated water.

“I would like to see a more mindful approach of taking care of this site,” Scola said.

Rich, who is running for City Council, said there are areas where burrowing animals have created deep holes in the ground. “The common perception is that the city is doing right by us – that the city is taking care of us,” Rich said during an interview at the landfill last week.

City Manager Jon Jennings responded during the meeting last Monday by acknowledging that the city has not been meeting its obligations at the landfill, but now planned to do so.

“We are taking this very seriously,” Jennings said. “In terms of timelines and so forth for the solar project, that’s obviously important, but making sure this landfill is fully capped for the foreseeable future is a priority of the city.”

Jennings added, “Please know, it’s one of those things, in all honesty and in all candor, it hasn’t been addressed in many years and it should have been addressed and we’re addressing it now.”

DEP: LEACHATE A THREAT TO PETS, NOT HUMANS

The Ocean Avenue landfill in East Deering is rimmed by trails maintained by Portland Trails. From atop the 50-foot mound, one can catch a glimpse of Casco Bay. It’s near the Quarry Run dog park, but many pet owners allow their dogs to run off-leash along the road that rims the old fill.

Between the road and the landfill are areas of tall grass filled with colorful flowers. However, these are areas where potentially contaminated water seeps out of the landfill. And that leachate can be harmful to pets.

According to the Maine Department of Environmental Protection, leachate is forced out of the landfill by water that collects on top and infiltrates the capped fill. The top of the landfill should be rounded so water runs off the hill, DEP said. Portland’s landfill is mostly flat.

The leachate has been determined to be unhealthy for pets that frequent the area, but not humans, according to DEP.

Matt Young, project manager for the DEP’s Landfill Closure and Remediation Program, said leachate is a common problem for landfills that were closed in the 1970s, like Portland’s. But details about what exactly is in the landfill – and its potential toxicity – are difficult to come by, mostly because the landfill was also used by surrounding towns, including Scarborough and Westbrook, he said.

“Portland seems to have more complications, but it also did a lot more than most municipal landfills did,” Young said.

The Ocean Avenue landfill was informally closed in the late 1970s, but was not formally closed and capped until the 1990s. However, it was grandfathered in and exempt from newer regulations, and only needed to comply with those that were in effect in the 1970s, the DEP confirmed.

According to a 1996 summary of the landfill’s history by Sebago Technics, which was working on behalf of the city, the landfill was capped with 24 inches of materials, including sludge from the Portland Wastewater Treatment Plant, which the DEP approved. Over the years, the city has had to contend with people illegally dumping materials at the closed landfill, including construction debris and bulky waste, such as appliances and wrecked vehicles.

Erosion from ATVs and leachate were observed in 1996. At the time, tree and brush growth were noted as a concern, since the roots could damage the cover system.

“Although the landfill encompasses a fairly large area (approximately 35 acres), the level of closure performed by the city of Portland appears to be functioning adequately and in general compliance with the 1976 MDEP closure requirements,” wrote Owens McCullough of Sebago Technics.

A decade later, in 2008, the DEP warned about woody vegetation again.

“While it appears the cutting of a large portion of the landfill may have been done in the past, the clumps of woody vegetation remain in place and will eventually migrate onto most of the remaining surface if left unattended,” Robert Birk, of the DEP’s Division of Remediation in the Bureau of Remediation and Solid Waste, wrote in a letter to the city.

In 2009, the DEP received a complaint from the owner of a dog that had gotten sick after drinking some of the leachate. It received a second complaint later that year. Emails from the DEP indicate remediation work within the past 10 years initially slowed the leachate seeps, but they had since gotten worse.

The state urged the city that May to conduct surface water tests, since the area was being used increasingly for recreation. That August, the city’s water test at one of the locations shows “very high levels of lead, arsenic, chromium, iron, manganese, etc. Not good for mammals to drink – I’m sure of that,” Birk wrote in an email to DEP staff.

SUGGESTIONS FOR PROACTIVE APPROACH

Over the course of the next few years, DEP officials reiterated that they did not believe there was a significant public health threat to people using the perimeter trail, only to animals that may drink or come into contact with the water. They were not concerned about infiltration into groundwater, because surrounding homes used public water.

The DEP recommended that the city put up a fence and signs telling people that the water was not safe for pets to drink. It also brought up long-term remediation plans, since the leachate was likely affecting surface water.

“A proactive approach by the city now will likely save a considerable amount of time and expense later trying to address citizen concerns,” Birk wrote.

Sustainability Coordinator Troy Moon, who was the city’s solid-waste manager at the time, emailed the state that December, saying the city would install warning signs. A month later, Mike Bobinski, then the public works director, indicated that the signs were still being printed.

In July 2010, the DEP sent a letter to the city approving the sign placements, but urging it to do more to prohibit people from biking and using ATVs on top of the landfill and to add more fencing to keep pets out of the leachate areas. It also recommended that the city cut the grass more frequently to control the growth of woody plants that can damage the landfill cover.

The DEP also asked at the time that the city provide a plan to “implement the additional maintenance, management and monitoring steps.” The department stopped short of calling for more comprehensive measures to resolve the issues with the landfill cover, the deficiencies of which were leading to the leachate seeping out.

In November 2010, the DEP had still not received a response from the city.

“Certainly enough time has reasonably gone by from that date for the city to have developed an adequate response,” Birk wrote. “It is very important that we receive this plan no later than November 30, 2010, or we will need to consider other measures to assure compliance with this requirement.”

The city complied with that request.

REMEDIATION TO COST AT LEAST $150,000

After a site visit in May 2015, the DEP asked the city to repair fences between the access road and the leachate, as well as fix erosion issues. Additional letters were sent to city officials the following year, highlighting the need for the city to address the ponding on top of the fill, which prompted seepage, by regrading the site.

In June of this year, the city presented formal plans to the Planning Board to do exactly that. Public Works Director Chris Branch said in an interview Thursday that the project will cost at least $150,000, even though the city is using fill from its State Street road project to increase the height of the landfill by 3 feet.

Branch said the project cost does not include seven vents that will need to be installed to mitigate methane gas that was detected on the site. The city is still awaiting cost estimates for that work, he said.

There’s a lot riding on the landfill work, including the city’s ambitious solar project.

In addition to addressing negative environmental impacts of the leachate, the city recently amended an agreement with Kenyon Energy, the company that will assume ownership of the solar array after it’s installed by ReVision Energy. The city plans to purchase the solar array at some point, but until that happens it will be paying a premium for the electricity.

If the solar array has to be taken off-line or removed because of problems with the landfill or other regulatory issues, the city would be liable for the costs of any electricity that would have been produced, were it not for those issues.

Moon was not able to provide an estimate of how much that might cost, if the landfill fails in the first few years.

“I don’t think we’re able to speculate on a worst-case scenario,” he said. “There are too many variables to provide a reasonable answer to that.”

Randy Billings can be contacted at 791-6346 or at:

rbillings@pressherald.com

Twitter: randybillings