Portlands Energy Centre Inc., the company that owns the Napanee Generating Station through Atrua Power, has been convicted of violating the Environmental Protection Act (EPA), according to the Ministry of the Environment, Conservation and Parks (MECP).
In May of this year, Portlands Energy Centre Inc. was convicted of the violation in the Napanee Provincial Offences Act Court. That violation was “failing to comply with ministry approval by failing to operate a sewage works such that the effluent parameter for Total Residual Chlorine did not exceed the Daily Concentration Limit.”
According to conviction documents recently published by the ministry, the violation occurred on or about July 2020.
Napanee Generating Station, a natural-gas-fired electricity generating plant on Loyalist Parkway in the Town of Greater Napanee, operates industrial sewer works. According to the ministry, in July of 2020 the sewage system was operating in violation of the requirements of an Environmental Compliance Approval (ECA).
The power station operates a water circulation system in order to remove waste heat from the steam turbine generator condenser. The waste heat is then expelled into the atmosphere via cooling towers, and Portlands Energy Centre Inc. adds chlorine to the cooling water as an anti-foulant — that is, to remove pollutants.
MECP explained that “blowdown” is a term for water that is periodically removed from the recirculated cooling water in the cooling towers to reduce contaminant buildup or fouling of the system.
“The blowdown must be treated prior to being discharged from the facility into the natural environment in order to ensure that it meets effluent limits specified in the ECA,” the ministry explained in its findings.
Portlands Energy Centre Inc. is required to sample that effluent for “various parameters” to ensure those parameters are within the Daily Concentration Limits, as per the ECA. On July 11, 2020, a sample analyzed from the facility for Total Residual Chlorine (TRC) found that the TRC concentration exceeded the Daily Concentration Limit, according to MECP. A second sample confirmed this exceedance; as a result, Portlands Energy Centre Inc. then “immediately closed the effluent valve to stop the discharge.”
The company notified MEPC’s Spills Action Centre, and the ensuing investigation found that the over-concentration of residual chlorine was the result of a sodium bisulfite supply being allowed to run “to a low but not empty level,” the ministry said. Sodium bisulfite is a chemical added to the blowdown water to neutralize chlorine before the blowdown water is expelled into the natural atmosphere. According to MEPC, the low level of sodium bisulfite caused a suction issue, stopping the flow of sodium bisulfate into the blowdown water.
“As a result of the incident, an estimated 476,000 litres of wastewater effluent was discharged into the environment,” the ministry stated.
“There was no evidence that the exceedance caused harm to aquatic life.”
According to MEPC, Portlands Energy Centre cooperated with the ministry throughout the investigation on a voluntary basis and implemented “enhanced technology and prevention techniques at the facility on its own accord and expense as preventative measures.”
The court found that Portlands Energy Centre Inc. was guilty as charged by MECP’s Environmental Investigations and Enforcement Branch with one violation under the Environmental Protection Act. The company was fined $25,000 and given 45 days to pay.