New England’s largest plumbing
job is a wrap
– MetroWest water supply tunnel opens
The Plumbing Heating and Cooling Contractors of Greater Boston are integral
players on the region’s largest projects. From Boston’s new convention
center to the Big Dig, Local 12 craftspeople are on the front lines. But the
Massachusetts Water Resources Authority’s (MWRA) MetroWest Tunnel, part of
its new water transmission and treatment system, is the mother of all
plumbing projects.
When it opened in November 2003, the 17.6-mile long, 14-foot wide tunnel
represented 7 years of construction, $665 million in costs, and an
investment of 6 million labor-hours. Nearly 2000 people, including Local 12
members, worked on the project. Tunnel work proceeded 24 hours per day on 3
shifts, 5 to 6 days per week, with no fatalities. The project focused on 5
primary shafts in Marlborough, Southborough, Framingham, and two in Weston.
The MWRA finished on time and well below its $728 million budget.
Local 12 Business Agent George Donahue visited the tunnel as it was being
built and dubbed it an “historic project.” He says that traveling 300 feet
underground on an elevator to reach the work site was like going on a theme
park ride.
Serving 39 communities in the Metro Boston and MetroWest regions, the
project was a logistical challenge of epic proportions. Yet, the 2.3 million
people who rely on the tunnel for their water probably didn’t notice a thing
when the MWRA switched open the valve. And that’s as it should be.
As they do every day, people filled their drinking glasses, took showers,
and flushed their toilets without any pressure fluctuations or discolored
water problems. Behind the scenes, however, up to 450 million gallons of
water per day began flowing 200 to 450 feet underground.
The MetroWest Tunnel essentially replaces the aging, leaking, and vulnerable
Hultman Aqueduct as the region’s water lifeline. A surface aqueduct running
continuously since the early 1940s, the Hultman will get an overhaul and
then become a backup to the new tunnel.
More work in the pipeline
In addition to the tunnel, the MWRA opened two of three cells that comprise
the new 115 million gallon Norumbega Covered Storage Tank along the Mass
Pike in Weston. Meanwhile, the agency is using the old Wachusett aqueduct to
move water from the Wachusett Reservoir down to the Marlborough area where
the tunnel starts. That allows the MWRA to take the Cosgrove Tunnel off-line
over the winter months so that it can connect the new tunnel to the Walnut
Hill Water Treatment Plant under construction in Marlborough.
Phase 2 of the new system will take place this spring when the MWRA connects
the Cosgrove Tunnel and turns on the third Norumbega tank cell. Phase 3 will
begin when the Walnut Hill treatment plant starts providing treated water in
early 2005 using ozone gas as the primary disinfectant instead of chlorine.
The tunnel is the backbone of MWRA’s $1.7 billion Integrated Water Supply
Improvement Program. This multi-faceted program, which includes water
transmission, treatment, and storage, represents the biggest investment in
New England’s largest water system since the building of the Quabbin
Reservoir during the Great Depression.
