A proposal to more than double the size of Connecticut\u2019s only ash disposal landfill was approved by state regulators despite objections from environmentalists who say there is a risk that contaminants at the site could leak into local groundwater sources and the Quinebaug River. The Department of Energy and Environmental Protection issued its final decision Dec. 14 to allow the Wheelabrator ash monofill in Putnam to proceed with its planned expansion from 60 acres to nearly 128 acres, while also granting modifications to the company\u2019s existing solid waste and discharge permits. The expansion will also allow the landfill, which opened in 1999 and is approaching capacity, to expand its life cycle by another 30 years of accepting millions of additional tons of ash from trash incinerators in Connecticut and New York. \u201cThe life expectancy of the current facility is expected (to) be reached in 2022,\u201d DEEP hearing officer Kathleen Reiser wrote in a proposal outlining her final decision. \u201cIf no other disposal is developed by that time, there will be nowhere in this region for disposal of the ash material.\u201d DEEP granted preliminary approval for the expansion last summer, however opponents of the project successfully petitioned for a public comment hearing in October, delaying final approval. During that meeting, conservation groups urged regulators to deny the expansion permit. Any break in the landfill\u2019s protective lining, they said, which would send harmful contaminants into the nearby Quinebaug River, which flows into the larger Thames River and eventually into Long Island Sound. The Boston-based Conservation Law Foundation also attempted to intervene against the Wheelabrator\u2019s permit request, saying the landfill expansion was unnecessary due to plans to close one of the largest incinerators sending ash to the site. DEEP denied the group\u2019s bid to intervene, though its staff was allowed to submit testimony during the public comment period. Kevin Budris, a staff attorney for CLF, said Wednesday the group was pleased that DEEP incorporated some of its concerns into the final permit approval, including a requirement that Wheelabrator monitor local groundwater for any contamination by a toxic group of chemicals known as PFAS. However, Budris criticized DEEP\u2019s overall decision to approve the landfill expansion as a contradiction of the state\u2019s commitments to reduce waste generation, which he said would likely result in the closure of all waste incinerators over the next 20 years. \u201cDEEP is opening Putnam for ash disposal of all of New England,\u201d Budris said. \u201cIt\u2019s inappropriate for Putnam residents to have to shoulder the burden of this ash disposal, especially when so much of it is coming from out of state.\u201d Wheelabrator Vice President Don Musial, however, said the company has no plans to close its nearby waste-to-energy plants \u2014 including its large facility in Bridgeport \u2014 regardless of whether its permit to expand the landfill were approved. In its final decision to issue the permit, DEEP noted that transporting ash longer distances to out-of-state landfills would result in more carbon pollution from trucks. The agency also said past monitoring of the Putnam landfill site has not shown any previous issues with the protective lining. \u201cAs a company, we\u2019re excited for the decision; this has been a 10-year process,\u201d Musial said Wednesday. He added that the public\u2019s feedback ultimately led to amendments to the permit that the company supported, including the requirement for PFAS monitoring. \u201cAs these standards are developed, we will be at the forefront of any facility that\u2019s required to monitor for PFAS,\u201d Musial said. Despite some local opposition, the expansion plan earned the support of Putnam\u2019s elected town leaders, who pointed to the nearly $60 million the town has received in host fees during the two decades that the landfill has operated. Those fees have helped the town stabilize its tax rate, and even contributed toward capital projects such as the construction of a new municipal building, officials said. \u201cThey\u2019ve been a great company to work with,\u201d Putnam Mayor Barney Seney said Wednesday. \u201cThey\u2019ve been helping our town with their donations and the money they put toward our budget.\u201d With regulatory approval in place, Musial said the expansion project will begin this spring with the installation of another 14 acres of protective lining. Once that lining is in place, he said the landfill will gradually expand in four phases over the next 20 to 30 years. During the landfill\u2019s extended operation, Musial predicted that Wheelabrator will pay another $100 million in fees to the town of Putnam.