Impact of sewer break on pond less than first feared

Posted 9/21/22

The Department of Environmental Management (DEM) had some good news for the otherwise catastrophic situation last week when a forced main sewer line ruptured on Lakeshore Drive.

Contrary to …

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Impact of sewer break on pond less than first feared


The Department of Environmental Management (DEM) had some good news for the otherwise catastrophic situation last week when a forced main sewer line ruptured on Lakeshore Drive.

Contrary to initial estimates, the sewage flowing into Warwick Pond was much less than stated in a DEM press release.

“In the midst of its emergency response to the sewer line rupture, WSA [Warwick Sewer Authority] initially overestimated the total volume of sewage discharged to the pond. WSA’s new estimate — based on a review by an engineer and data from the septic tank trucker haulers — is 161,600 gallons. This is still a major discharge, but much less than the 450,000-gallon estimate included in DEM’s Sept. 13 press release,” DEM spokesman Michael Healey writes in an email response to questions about the incident and authority plans going forward.

According to WSA Executive Director Bettyanne Rogers, ongoing tests of the pond show a declining level of bacteria although she didn’t have specifics at this time. She said test results are being compiled by the Department of Health.

“It’s fixed,” Rogers said of the 24-inch line that joins a transmission line off Airport Road feeding wastewater into the treatment plant on the banks of the Pawtuxet River. The rupture was caused by deterioration of the cement resulting from age and the corrosive effects of hydrogen sulfide gas emitted by sewerage.

In order to restore the line that ruptured a week ago Tuesday, the WSA needed to bypass that section of pipe. Meanwhile, the flow in the pipe representing sewage collected from the southern portion of the city including Warwick Neck, Oakland Beach and the Sandy Lane area continued. No customers lost service and, since the break occurred in a transmission line, there was no treat of backups into homes or businesses. To minimize spillage into the pond, the WSA had septic tanker trucks capturing what flowed into a storm drain.

By early Wednesday morning the bypass was operational and flow into the pond corked.

The WSA identified the line as a weak link in the system more than a year ago and developed a plan to repair it. Specifications were in the process of being finalized with the intent of seeking construction bids in November.

Rogers said that schedule is being moved up. She estimated the cost of the project at about $3 million.

Healey said the authority has submitted a Clean Water State Revolving Fund application that is under review by DEM.

He added in light of the break, WSA would expedite its bid posting for the project. He said the WSA has reached out to potential bidders to determine if there may be supply chain issues for rehabilitation materials and were told that there do not appear to be any delays. Further expediting overall restoration of the line, the authority is moving ahead with a by-pass on airport property.

Rogers pointed out that it will serve as an added measure of security should there be another rupture in the line before work starts.

As for pond water, Healey said the no-contact advisory remains in effect for the pond, creek and upper bay conditional shell fishing area A. He said DEM and the Department of Health (DOH) as well as the authority continue to sample for water quality in Warwick Pond and the downstream freshwater and saltwater receiving waters. DEM submits the samples to RIDOH.

“As of today, we don’t know when we’ll be in a position to lift the advisory,” Healey wrote Tuesday.

In a follow up email yesterday, Joseph B. Haberek, PE Administrator of Surface Water Protection, of the DEM wrote that water samples have demonstrated a decline in bacteria levels since the initial spill. 

“In addition, water quality samples collected in shellfishing Area A by DEM on Thursday 9/15 and Monday 9/19 have indicated that bacteria levels have returned to normal, low background levels in all of Upper Narragansett Bay Area A except an area at Mill Cove. Accordingly, DEM reopened the majority of Upper Narragansett Bay Area A to shellfishing as of this morning.  However, shellfish harvest continues to be prohibited in the waters west of a line extending from Conimicut Point to the extension of Ogden Avenue in Warwick . This 170-acre area is the area that had slightly elevated bacteria concentrations and will remain closed to shellfishing until further notice.  DEM will continue to test bacteria levels to track recovery after the Warwick Pond sewer spill and will reopen the entirety of Area A once the data supports reopening the remaining 170 acres.”

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