Final Permit Granted for Mirant Canal Station's Water Discharge
The Mirant Canal Station Power Plant in Sandwich, MA is once again under the spotlight, as the Environmental Protection Agency (EPA) has re-noticed the plant's permit for public comment. This move comes in response to the 2008 re-noticing process initiated over the power plant's Clean Air Act permits.
The current permit conditions primarily focus on stringent limits and requirements to reduce air pollutant emissions, specifically sulfur dioxide (SO₂), nitrogen oxides (NOₓ), particulate matter (PM), and mercury. Key elements of the permit conditions include:
1. **Emission Limits**: Specific numeric limits on pollutants, consistent with best available control technology (BACT) and state implementation plan (SIP) requirements. 2. **Continuous Emissions Monitoring**: Requirements for continuous emissions monitoring systems (CEMS) for key pollutants to ensure compliance and facilitate real-time reporting. 3. **Operational Restrictions**: Conditions governing plant operation to limit emissions during certain periods or under specific meteorological conditions to protect air quality. 4. **Reporting and Recordkeeping**: Obligations to maintain detailed operational records, emissions data, and periodic reporting to the EPA and state environmental authorities. 5. **Compliance Demonstrations**: Mandated performance tests and ongoing compliance demonstrations to verify adherence to emission limits. 6. **Public Engagement**: Provisions for public access to permit documents and opportunities for continued engagement or appeals.
In addition to the air pollution controls, the permit also includes provisions related to the plant's water discharge. The final permit requires modifications to the cooling water intake structures to reduce impingement mortality, and discharge temperature limits have been set to maintain the biological integrity of the receiving water.
The withdrawn and re-noticed provisions include Parts I.A.2.f, I.A.7.f, I.A.8, I.A.13.g, and I.A.13.h of the August 2008 Final Permit. These changes are based on EPA's determination under section 316(b) of the Clean Water Act that closed-cycle cooling is the best technology available for minimizing adverse environmental impact.
The public was invited to submit written comments on the draft permit conditions from December 12, 2008 to January 29, 2009, and a public hearing was held on January 14, 2009 at the Forestdale School in Sandwich, MA. The appeal of the August 2008 Final Permit is currently pending with EPA's Environmental Appeals Board.
The new draft permit conditions are accompanied by a supporting Fact Sheet, and the official EPA permit documentation is available on the EPA’s Region 1 environmental permits webpage or through the Massachusetts Department of Environmental Protection. For a more precise and legally binding understanding of the permit conditions, it is recommended to review these official documents.
The MCS federal and state permit number MA0004928 was last reissued on June 23, 1989, and the NPDES permit issued to Canal Station in 1989 remains in effect pending the resolution of the appeal. An extensive bio-monitoring program is required to gather information about the entrainment and impingement impacts from MCS.
The Region has requested the EAB to stay the pending appeal until the new draft permit conditions are finalized. Metal cleaning waste water has been segregated from other internal waste streams for sampling. The "Responses to Comments for Mirant Canal Station" document summarizes comments and EPA's responses.
For those interested in staying updated on the progress of the Mirant Canal Station Power Plant's permit, it is advisable to regularly check the EPA’s Region 1 environmental permits webpage or the Massachusetts Department of Environmental Protection's website.
- The water discharge from the Mirant Canal Station Power Plant is regulated in the new draft permit, requiring modifications to the cooling water intake structures to minimize impingement mortality and setting discharge temperature limits to protect the biological integrity of the receiving water.
- The financing for the modifications to the cooling water intake structures is not explicitly mentioned in the permit documents, but it could potentially be a topic of interest in the general-news given the concerns about the power plant's environmental impact.
- The Environmental Protection Agency (EPA) has re-noticed the permit for the Mirant Canal Station Power Plant, with provisions for public engagement and continued access to permit documents, creating an opportunity for environmental-science experts and the general public to provide input on the plant's operations and impact on the environment.
