LIHI Certificate # 50 --- Alternatives Hydroelectric Project (FERC No. 12608) Mumford River, Massachusetts
Portland, Maine (April 21, 2010) - The Low Impact Hydropower Institute at their regular monthly meeting, the Institute's Governing Board determined that the Alternatives Hydroelectric Project meets the LIHI Certification Criteria.
In reaching its decision to certify the Alternatives Hydroelectric Project, the Low Impact Hydropower Institute's Governing Board reviewed the application for certification, as well as the Application Reviewer's report and recommendations. Although the Alternatives Hydroelectric Project appears to be in compliance with LIHI's criteria, the fact that the project is not yet in operation results in the Board certifying the project, with the following project specific conditions:
The Alternatives hydroelectric project is certified, for a term of twelve months, with the certification extended for an additional forty-eight months when the Applicant demonstrates to LIHI that it has complied with the conditions outlined in its December 2006 and March 2008 FERC exemptions. The Board's vote to certify the Alternatives Hydroelectric Project with Project Specific conditions was unanimous. LIHI received no Public Comments on the application.
LIHI certification for the Alternatives Hydroelectric Project is granted, with the certification time period beginning on January 19, 2010.
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LIHI Pending Application -- (FERC No. 12608) Alternatives Hydroelectric Project on the Mumford River, Massachusetts
Portland, Maine (January 19, 2010) – The Low Impact Hydropower Institute (LIHI) announced today that Alternatives Unlimited ("Applicant") has submitted an application for certification of the Alternatives Hydroelectric Project (FERC No. 12608). The Project is located on the Mumford River in the Town of Northbridge, Village of Whitinsville, Massachusetts. The Project Dam is called the Ring Shop Dam. The dam drains approximately 48 square miles with an average annual flow of 44 cfs. It impounds 2 acres and stores 16 acre-feet at proposed pool elevation of 285.1. Without the flashboards (at pool elevation 282.6), approximately 1.3 acres are impounded or approximately 700-linear feet. The height of the dam from its toe to the top of its abutment is 15.5-feet. The spillway height is 9.5 feet and the normal hydraulic head on the structure, with 30-inches of flashboards installed, is 12-feet.
The Project consists of a 93.5-foot concrete ogee spillway, a waste gate, and two inlet structures located at the north and south ends of the spillway. The ogee crest is fitted with sockets to accommodate 2½ inch pipes, 30-inches tall on three-foot centerlines. The crest is designed to be fitted with 30-inch tall flashboards. The crest elevation is 282.6 (282.0 msl original datum). The deeded water rights allowed the impoundment to be raised to 285.1 (284.5 msl original datum) with the flashboards installed.
The dam was originally constructed to impound and convey the waters of the Mumford River to the shops of the Whitinsville Machine Works constructed on both banks of the river. Both intakes are now abandoned. The turbine generator sets for the northern intake were removed in the 1980s when the shop was converted to an assisted living facility. At that time, the intake canal was sealed off and the hydro power was abandoned. The Machine Works Shop is now occupied by Cotton Mill Apartments, an assisted living complex on the downstream side of Douglas Road.
The southern intake was abandoned at the turn of the century. It consists of a silted forebay, which leads up to a wooden headgate. This gate is located beneath the lower Alternatives Building. The top of the headgate is visible in the silt and has slid sideways. Under prior conditions, the water was conveyed through a short five-foot diameter stub penstock to a turbine casing located beneath the same building. An existing tailrace conveyed the water back to the Mumford River just upstream of the southerly abutment of the Douglas Street Bridge.
The original timber crib dam was destroyed in a 1938 flood and was replaced in its entirety in 1941 with a concrete gravity structure. It was originally proposed to reconstruct the existing southern forebay, intake gate, discharge pit and tailrace and install the turbine in the approximate location of the former hydro equipment. However, due to the deterioration of the existing hydro-infrastructure, the turbine was installed outside the building, on the south side of the dam, just downstream of the flood-gate opening. The power unit is one (1) 47 kW Leroy Somers Tube Turbine, which has a hydraulic capacity of 70 cfs. The expected plant factor is 82%. It is anticipated that all generated electricity would be utilized by Alternative's facility, except during low power demand, when net metering will occur. Massachusetts Electric Company provides transmission at the site.
The Project is to be operated strictly "Run-of-River" and the outflow will equal inflow. No "Peaking" or "Ponding" will occur. The unit will be equipped with a pond levelingdevice to accurately match the turbine discharge with flow conditions. The units willdrop "off-line" and the turbine gates will close automatically should flows drop too lowfor efficient operation. Further, all minimum stream flows will be maintained as requiredby the agencies. The units will be semi-automatic; they will be started up and put "online" manually and will shut down under all fault or low flow conditions. The Trashrack provided is a 20-foot long (1/4-inch x 3-inch flat stock), with clear spacing of 3/4-inch and 45º angle to flow as designated by the U.S. Department of the Interior and MA Department of Fish and Wildlife.
Public Comments - We encourage public comments on this application. Specifically, we are interested in knowing whether you think the Alternatives Hydroelectric Project meets our LIHI criteria. Review the program and criteria in greater detail and then review the Alternatives Hydroelectric Project's application. Comments that are directly tied to specific LIHI criteria (flows, water quality, fish passage, etc) will be most helpful, but all comments will be considered.
Comments may be submitted to the Institute by e-mail at info@lowimpacthydro.org with " Alternatives Hydroelectric Project comments" in the subject line; by fax at (206) – 984-3086; or by mail addressed to LIHI, 34 Providence Street, Portland, ME, 04103. Comments must be received at the Institute on or before 5 pm Eastern time on March 19, 2010 to be considered. All comments will be posted to the web site and the applicant will have an opportunity to respond. Any response will also be posted.