The City of Los Angeles Department of Public Works is in the midst of an environmental review process for the proposed Venice Pumping Plant Dual Force Main project.
The project includes a proposal to construct and install a new force main sewer line extending from the Venice Pumping Plant at 140 Hurricane St. in Venice to the North Outfall Sewer near Waterview Street in Playa del Rey.
Public comment on the draft environmental impact report (EIR) ended Friday, March 17th.
City officials have proposed four different construction alignments and will decide on one option after comments from the public have been reviewed.
“We have designated a preferred alternative,” said James Doty, a Department of Public Works engineer. “We are using the EIR process to figure out which alternative people want us to build.”
Currently, all of the wastewater from the Venice Pumping Plant is carried in one sewer line.
During severe weather, the wastewater flow exceeds the capacity of the sewer line.
Because there is only one sewer line, the Department of Public Works cannot shut it down for maintenance.
A new sewer line would ensure that another line is always available as backup for use in severe weather or for use during maintenance.
The four proposed alignments under consideration are:
n Marquesas Way/Via Marina: From the pumping plant on Hurricane Street, this alignment extends east under the Grand Canal and along Marquesas Way.
The sewer line would then continue southeast on Via Marina, cross under the Marina del Rey entrance channel and Ballona Creek channel, and south on Pacific Avenue to Waterview Street.
n Pacific Avenue: This possible alignment proceeds west on Pacific Avenue from the pumping plant, turns south on Pacific to cross under the Marina del Rey and Ballona Creek channels and stops at Waterview Street.
n Dockweiler Beach to Pacific Avenue: This alignment extends west on Pacific Avenue to an existing 20-foot-wide sewer easement at the north side of Dockweiler State Beach.
The line then turns south on Pacific Avenue to cross under the Marina del Rey and Ballona Creek channels, and continues south to Waterview Street.
n Dockweiler Beach: From the pumping plant on Hurricane Street, this alignment proceeds west to the 20-foot-wide sewer easement at Dockweiler State Beach, crosses under the Marina del Rey and Ballona Creek channels, and continues south along the beachfront to Waterview Street.
All four alignments involve 1,800 feet of tunnels under the Marina del Rey entrance channel and the Ballona Creek channel.
Department of Public Works engineers are also considering three construction methods.
n Cut and cover allows construction to be done in short segments, as opposed to doing work on the whole project the same time.
n Small-diameter micro-tunneling, or boring, is a trenchless method that utilizes hydraulic jacks to push pipes through the ground behind a tunnel-boring machine that is operated by remote control.
n Large-diameter tunneling, or mined tunneling, utilizes manned tunnel boring machines, which eliminate the need for the continuous jacking of pipes through the ground.
“We don’t want to talk about costs of each until we have reviewed the environmental impacts,” Doty said. “Open cut (cut and cover) is the least expensive and the fastest, but it has the most impacts on the surface.
“Deep tunneling (large-diameter) is the most expensive and slowest, but it has the least impacts on the environment.”
The draft EIR has some conclusions about long-term and short-term impacts.
No operational long-term impacts could be found and impacts to air quality, geology and soils, hydrology and water quality, and storm-water control can be mitigated, the EIR indicates.
Impacts to community aesthetics, noise, public services, transportation and traffic are considered unavoidable short-term significant impacts, the EIR says.
“Because of the nature of the communities we are in, we called less serious impacts significant impacts,” Doty said. “Most of the impacts can be mitigated to an acceptable level, but there are some that everyone will just have to live with.”
Department of Public Works engineers believe that, for environmental reasons, cut and cover construction on Dockweiler State Beach and small-diameter tunneling on Pacific Avenue are infeasible.
Large-diameter tunneling is an environmentally superior alternative for Dockweiler State Beach and Pacific Avenue, engineers say.
“The lagoon and ‘Jungle’ areas of Playa del Rey cannot function if the roads are reduced,” asserted Carol Kapp, a Playa del Rey resident and a board director of the West Beach Playa del Rey Property Owners Association. “Using the beach for tunneling will disrupt the least [number] of local residents. This project must be monitored carefully.”
The sewer line was originally built in 1928 as a 36-inch reinforced concrete pipe.
In 1958, the line was connected to the new Venice Pumping Plant’s four pumps and rebuilt as a 48-inch reinforced concrete pipe.
A fifth pump and new wet wall were added to the reconstructed plant in 1987.