PROVIDENCE, R.I. (AP) — Rhode Island Gov. Lincoln Chafee has descended 250 feet under Providence to see a huge subterranean tunnel being built to protect the health of Narragansett Bay.

Chafee and members of the media toured the tunnel Tuesday. It's part of a $1 billion project to divert storm water runoff and prevent sewage from polluting the bay.

The effort is one of the largest public works project in state history.

Crews have already completed a three-mile, 26-foot-diameter tunnel deep under Providence.

Without the project, water from heavy rains overwhelms sewage treatment plants and sends significant pollution into the bay.

The project was mandated by federal environmental laws. It's being funded through sewer bills and won't be completed for several years.

Chafee says protecting the bay is critical to the state's economy.

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