Merrimack scrubber cutting emissions by more than expected

A new SO2 scrubber on the coal-fired Merrimack power plant has significantly reduced mercury and sulfur emissions from the plant, according to a progress report recently filed by Public Service of New Hampshire (PSNH) with the New Hampshire Public Utilities Commission (PUC).

Recent tests show that the project is reducing mercury emissions by 97%-98%, well above the 80% mercury reduction requirement set by the New Hampshire Legislature, PSNH, a unit of Northeast Utilities (NYSE: NU), noted in an April 9 statement. It is also reducing SO2 emissions by 96%-98%, which exceeds the project’s 90% SO2 reduction goal.

“We are pleased to report that the Clean Air Project is achieving exceptional success,” said William Smagula, PSNH Director of Generation. “Already ahead of schedule and under budget, the scrubber is now also beating the clean air benchmarks set by the State Legislature.”

The installation of the wet scrubber at Merrimack was mandated by the state Legislature in 2006 and is aimed at reducing emissions of mercury and other pollutants. The filing to the PUC also reported on the status of the project’s construction work and overall cost. The construction of the project has to date entailed more than 1.3 million man-hours of work over a three-year period, all of which was completed without any lost-time accidents. The remaining construction work associated with the project is expected to be completed in June.

The final cost of the project is projected to be $422m, a reduction of $35m compared to the initial project budget of $457m. The scrubber project was declared in-service in September 2011, almost two years ahead of the July 2013 deadline set by the Legislature.

Merrimack, a 440-MW coal facility, is PSNH’s largest power plant and was put into service in the 1960s.

Incidentally, PSNH said in a March 28 posting to a special blog that the New Hampshire House of Representatives voted that day to table HB 1238, which would force the sale of the utility’s generating assets by 2013, by an overwhelming margin of 304-19. By tabling the bill, the House effectively is killing it for now, though the issue could return later in the legislative session if the Science, Technology & Energy committee opts to amend a Senate bill.

“For now, however, a great victory has been achieved in stopping this harmful legislation due in large part to the support and efforts of PSNH employees who placed hundreds of calls to House members over the past week and to the many business organizations and community leaders who supported our position,” said the PSNH blog post.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.