Councilors look to diminish use of chlorine gas

LYNN – Chlorine gas used at the Commercial Street waste treatment plant poses “potential dangers,” including domestic terrorism, to plant workers and residents in surrounding neighborhoods, according to city councilors who want its use phased out.?We understand that the use of chlorine gas is being phased out at many other plants across the country and its use is discouraged due to the risks associated with its use,” councilors wrote in a letter sent to the Water and Sewer Commission on Monday.Chlorine gas is “seen as a potential terrorist target,” said New England Water Works Director Ray Raposa.He said federal officials following the Sept. 11, 2001 terrorist attacks directed utilities, including treatment facilities, to prepare risk management plans including inventories of chemicals stored and used in facilities.The Commercial Street plant and the Parkland Avenue water plant are almost the only treatment facilities in the state still using chlorine gas, said waste treatment plant operations director Robert Tina.Most treatment facilities around the country switched to liquid chlorine – common household bleach – in their treatment processes.?Modern facilities don?t use chlorine gas,” said Water and Sewer Executive Director Daniel O?Neill.Raposa said many utilities switched to liquid chlorine after 2001, in part, because “chlorine gas has been seen as a bigger hazard.”?Comparing liquid and gas chlorine, depending on how much gas is used, could impact an entire neighborhood,” Raposa said.Council concerns about accidents, vandalism and terrorism incidents associated with chlorine gas used in the plants are accurate, Tina said, adding safety measures in place at the plants for chlorine gas passed a 2012 federal occupational safety inspection.The treatment plant is operated by Veolia Environmental Services, and Tina said two workers were injured during the last 15 years in chlorine-related incidents at the plants. He said the employees required hospitalization and said the incidents occurred during maintenance work.?Chlorine gas has a lot of dangers associated with it,” Tina said.The Commercial Street plant is designed to treat more than 25 million gallons of waste every day. Tina said chlorine gas is injected into liquid waste as the treatment process nears completion. Before the treated liquid is discharged into the ocean, a chemical process is used to neutralize the gas.In their letter to the commission, Council President Daniel Cahill and Ward 6 Councilor Peter Capano said chlorine gas not only poses a danger to plant workers but also to “significant portions of Lynn and Nahant” in the event of an accident.?We strongly urge work begin to eliminate the use of chlorine gas at the Waste Water Treatment Plant as soon as possible,” wrote Cahill and Capano.Commissioner and former councilor David Ellis initially raised concerns about chlorine gas use in Water and Sewer facilities during an October 2013 commission meeting.Tina said Cahill and Capano are correct in noting the treatment plant?s chlorine system is almost 30 years old. He said Veolia estimates replacing gas systems at the waste and water plants with liquid chlorine systems will cost $2.5 million.A Water and Sewer consultant will review that estimate before recommendations for converting to liquid treatment are sent to the five commissioners, Tina said.?It will be up to the board to decide what they want to do,” he said.