The Federal Energy Regulatory Commission on June 30 went out for 30 days of comment on an environmental assessment covering a February 2014 application from FFP Missouri 12 LLC on a license for the construction and operation of the Allegheny Lock and Dam 2 Hydroelectric Project.
The 17-MW project would be located at a U.S. Army Corps of Engineers dam at river mile 6.7 on the Allegheny River in Allegheny County, Pennsylvania. The project would occupy 3.23 acres of federal land owned by the Corps.
The Monongahela and Allegheny Rivers join to form the Ohio River in Pittsburgh, Pennsylvania. The Corps owns 38 locks and dams on these rivers—nine locks and dams on the Monongahela River, eight on the Allegheny River, and 21 on the Ohio River. The Corps operates these locks and dams for commercial and recreational navigation.
This proposed project would be located on the Allegheny River at the Allegheny Lock and Dam 2, which consists of a 1,380-foot-long, 52-foot-high fixed-crest concrete dam and a 360-foot-long, 56-foot-wide navigational lock. The entire length of the dam crest functions as an uncontrolled spillway.
The Allegheny Project would consist of a new 230-foot-long, 160-foot-wide intake channel to be excavated into the riverbed, replacing part of the north end of the existing dam crest and leading to a 120-foot-long, 170-foot-wide, 70-foot-high reinforced concrete intake structure that would convey flows past a trash rack with 5-inch clear bar spacing to a new 180-foot-long, 170-foot-wide, 70-foot-high powerhouse along the north bank of the river, housing three equally sized Kaplan turbine-generator units with a combined installed capacity of 17 MW. The project would operate in run-of-release mode, using flows made available by the Corps that would normally be released over the dam.
Flows would exit the powerhouse into a 170-foot-long, 155-foot-wide tailrace excavated into the riverbed. Two 45-foot-wide, 40- foot-high spill gates would be constructed within the intake channel to pass flow equivalent to the portion of the dam crest that would be removed, and an 1,100-foot-long series of 2.5-foot-high adjustable crest gates would be installed on top of the remaining dam crest to maintain the water surface elevation of the upstream pool.
Project power would be transmitted from the powerhouse to a new project substation with a 330-foot-long, medium-voltage, buried cable, and from there to an existing distribution line with a 1,265-foot-long, single overhead, 69-kV transmission line.
The applicant is a subsidiary of FFP New Hydro LLC. Rye Development LLC is acting as an agent for the applicant.