Naragansett Bay Gets $700-million Combined Sewer Upgrade
Complying with an environmental consent decree to stem polluting storm water and sewage from running into Narragansett Bay, Rhode Island officials have started a three-phase, $700-million-plus combined sewer overflow program in and around Providence. The initial work involves construction of a $165-million, 16,000-ft-long main spine storage and transport tunnel, seven 250-ft long drop shafts and 2,000-ft of interceptor lines. Click here to view map>>
The 147-sq-mile Narragansett Bay is an estuary of national significance that has more than 400 miles of shoreline in Rhode Island and Massachusetts. Recreational fishing generates about $300 million annually, while bay related tourism contributes another $2 billion to the local economy. CSOs account for about 85% of point source fecal coliform contamination. In the past, high coliform counts after storm events have triggered several shellfish closures. The RI Dept. of Environmental Management and the Narragansett Bay Commission agreed on a cleanup plan in 1992. But federal rules changed in 1994 and after publicly reviewing 17 different remediation scenarios over a two-year period, NBC selected its current plan. The agency hired Gilbane/Jacobs Civil as agency construction managers and then broke ground on the first project in June 2001 for the Moshassuck River Interceptor. The main spine tunnel was awarded to ML Shank/Balfour Beatty in 2001, but the shafts were broken out to allow for local competition.