Pittsfield NH dam repowering project

As governments and businesses consider the hydroelectric potential of existing non-powered dams, competition is heating up to claim and evaluate the best sites.  Federal regulators yesterday resolved a conflict between two developers by awarding a preliminary permit to a developer interested in studying the feasibility of repowering or rebuilding hydroelectric energy production at an existing mill dam on the Suncook River in Pittsfield, New Hampshire.

Another former mill dam in the heart of a New England village: the Doughty Dam in North Berwick, Maine.

Yesterday's order by the Federal Energy Regulatory Commission (9-page PDF) granted a preliminary permit to KC Hydro LLC of New Hampshire to study the feasibility of the Pittsfield Mill Dam Hydropower Project.  Originally built for industrial purposes, the Pittsfield Mill Dam is currently owned by the New Hampshire Department of Environmental Services.

As described in KC Hydro's original permit application (11-page PDF), the project concept involved either restoring an existing but mothballed 415 kW turbine which previously operated under an exemption from licensing, or installing entirely new facilities (potentially with a 530 kW capacity) to capture the hydroelectric potential of the water already impounded behind the dam.

After KC Hydro submitted its preliminary permit, another developer - AMENICO Green Solutions, LLC - applied for a competing preliminary permit for the same site.  AMENICO proposed a similar project, which focused on restoring the existing 415 kW turbine.  AMENICO noted that it had property rights to the site, which it claimed KC Hydro did not.

Noting that the applications were comparable, FERC recited its standard for resolving the competing claims:

Staff has reviewed the applications and found no basis for concluding that either applicant’s plan is superior to the other. Neither applicant has presented a plan based on detailed studies or the results of agency consultation. Where the plans of the applicants are equally well adapted to develop, conserve, and utilize in the public interest the water resources of the region, the Commission will favor the applicant with the earliest application acceptance date.

Because KC Hydro had applied first, FERC awarded the preliminary permit to KC Hydro.  In doing so, FERC noted that a permit applicant is not required to have obtained all access rights to a project site as a condition of receiving a preliminary permit.  However, FERC did note that a preliminary permit does not grant a right of entry onto any lands, so a permittee must obtain any necessary authorizations and comply with any applicable laws and regulations to conduct any field studies.

With its preliminary permit in hand, KC Hydro now has 3 years to investigate the site and apply for a full project license.  Will the Pittsfield dam ultimately be repowered?

February 15, 2011 - small non-hydro dam removal

From the dam removal department:

Picture a small dam stretching about 50 feet across a stream.  The Gravesleigh Dam on Sackett Brook in Pittsfield, Massachusetts was built in the 1930s by Merle Dixon Graves, a native of Bowdoinham, Maine who served in the Massachusetts House of Representatives from 1921-1924 and who owned Gravesleigh, an estate surrounding the brook just above its confluence with the Housatonic River.  Merle Graves had the dam built to create a small pond for his estate.  Over the years, the pond filled with silt, and much of the Gravesleigh estate became Massachusetts Audubon Society's Canoe Meadows Wildlife Sanctuary.

Now, Massachusetts Audubon is interested in removing the dam for reasons including improving water quality, restoring riparian wildlife habitat, and creating educational opportunities to learn about watershed health and science.  Moreover, as part of a deal to allow the Pittsfield Municipal Airport to expand, the dam site has been identified as able to offset some of the habitat lost at the airport as a condition for state water quality certification.  With the impoundment silted in, and no renewable power production at the site, these benefits may make the Gravesleigh Dam seem like a good candidate for dam removal.

The Housatonic Valley has a long history of industrial manufacturing, some of which resulted in PCB (polychlorinated biphenyl) contamination of the valley's soils and water.  According to EPA, "PCBs are probable human carcinogens and can also cause non-cancer health effects, such as reduced ability to fight infections, low birth weights, and learning problems."  If these chemical contaminants are trapped in the sediment impounded by the Gravesleigh Dam, the dam's removal could send the PCBs downriver into the Housatonic.  This is the same problem as found on Twelve Mile Creek in Clemson, South Carolina, where dam removal initiatives must be weighed against the risk of disturbing PCB-laden sediments.  In Pittsfield, dam removal could be paired with sediment remediation, but that would significantly add to the project's cost - already predicted to be $303,000 without sediment remediation.  This points to the importance of understanding what's trapped behind the dam.

Sampling of impounded sediments was undertaken last summer.  While most samples came back negative for PCB, one of the sediment samples did show PCB contamination.  This triggered another round of sediment testing last month.  The results of that testing have just come in, and suggest that sediment remediation will not be required for dam removal.

The Gravesleigh Dam's saga may soon be over.  In this case, chemical contaminants trapped behind the dam may not prove sufficient to prevent the dam's removal.   Each dam has its own story, and may have its own baggage that must be addressed if the dam is to be removed.  I'll keep you posted on the Sackett Brook story as it continues to flow.