Potential blasting near Shelton landfill raises methane gas concerns

SHELTON — The proposed development of a 40-unit apartment building on Mohawk Drive, not far from the landfill, has nearby residents concerned about increases of levels of methane in the area. 

The Connecticut Department of Energy and Environmental Protection presently oversees the landfill. The municipal solid waste portion closed in 1999 and the ash and hazardous waste portions closed in 2001. 

“The gaseous ‘burping’ that results from the breakdown of trash has reduced, though still needs to be managed,” said DEEP Director of Communications Will Healey. 

According to a CDC report, landfill gas is flammable in unventilated confined spaces, and exposure to the gas and the odor can trigger symptoms if the gas migrates off site.

At 2 Mohawk Drive, property owners Agim Ismali and Shprza Ismali are seeking approval for a Planned Development District on the site, allowing for development of a four-story 12,000-square-foot structure with 40 apartments with an outdoor parking lot and indoor parking under the building.  

According to the application, the developers would designate 30 percent of the apartments, 12 units total, as affordable under state statute 8-30g.   

The plans call for only one- and two-bedroom apartments on the site, which is located at the corner of Mohawk Drive and River Road. The property is bounded by Mohawk Drive to the east, a developed, residential area to the west, commercial development to the south, and Algonkin Road to the north. The land sits behind Casa Nova Ristorante, located on River Road. 

Dozens of residents appeared at a recent Planning and Zoning Commission public hearing to oppose this apartment application. During the hearing, the developers’ representatives suggested blasting may be necessary during the construction process. 

Regarding any blasting for such an apartment building, Healey said this, or any developer will likely need to evaluate the environmental setting and surrounding land use in the planning process. 

“Methane can migrate through known bedrock fractures at the landfill and in the vicinity of the landfill,” he said. “Blasting could potentially open new migration channels in the bedrock (and could cause some continuation of subsidence at the landfill).” 

According to Healey, this means that this or any developer may need to assess this potential when planning for construction of subsurface structures, such as basements and underground utilities. 

The DEEP Landfill Stewardship Operations Unit cares for this area and other closed regional landfills formerly managed by MIRA, CRRA and others, Healey said. In 2014, per legislative mandate, the post-closure care responsibility of the Shelton Landfill at 866 River Road transferred to DEEP. 

Property management tasks include managing the decomposition gas, methane, Healey said. 

“The methane produced by the decomposition of landfill waste has decreased significantly over the years,” Healey said, “Although the landfill continues to produce low levels of methane which is collected via an engineered system and ultimately burned off by an on-site flare.” 

The methane collection system and flare have been effective at controlling the methane on-site, he said. 

A flare is used because there is not enough methane to generate electricity, as can occur when landfill is first closed. 

“The methane collection system is continuously monitored in real time at the perimeter of the landfill and the flare is equipped with an alert system if the flare should shutdown,” said Healey, adding that DEEP has a contractor on-call to respond to any alarms, if they should occur, and address any disruptions in the flare system. 

The methane collection system is also visually inspected weekly, and routine repairs are made when necessary, he said.