By Bonnie Adams, Government Editor
Westborough – Renovations to the Westborough Wastewater Treatment Plant (WWTP) are nearly complete, a month ahead of schedule and $1.8 million under budget. All that is left to do for the $54 million project, according to Town Engineer Jack Goodhall, is a punch list.
The project was funded using a 20-year loan from the Massachusetts Department of Environmental Protection (DEP) State Revolving Fund at 2 percent interest and an approximately $8 million grant from the American Recovery and Reinvestment Act of 2009.
The plant, which was built in the mid-1980s, serves Shrewsbury – 60.8 percent, 4.39 million gallons of daily flow (mgd); Westborough – 35.48 percent, 2.89 mgd; and Hopkinton – 4.7 percent, 40 mgd. The renovation project was mandated by the DEP to limit the levels of phosphorous running into the Assabet River.
Phosphorus is found in agricultural fertilizers, manure and organic wastes in sewage and industrial effluent. Environmental groups and municipal officials agree that excessive amounts can be harmful to fish and plants in bodies of water, but disagree on what is considered an excessive level.
Goodhall noted that managing the levels of phosphorous in the Assabet and guidelines on how to treat it have changed significantly over the last two decades. Initially when the plant was built, officials were told not to be concerned with phosphorous, he said. Over time they were told it must be treated. Those standards have steadily increased over the years, he added.
“It's tough for the DEP and EPA [Environmental Protection Agency],” Goodhall said. “They must listen to the environmental groups, who want tougher standards. They also must listen to the towns, many of whom say the new mandates are too costly a burden.
“Because it's not just the capital expenses, it's also ongoing annual expenses, which get passed on to the users,” he added.
Sometimes, as in the case of the Upper Blackstone Treatment Plant in Millbury, officials are being told by the DEP and EPA they must make additional changes, even as they have not yet completed previously ordered mandates. (See http://communityadvocate.com/2012/01/18/selectmen-support-appeal-of-new-epa-water-treatment-regulations).
As part of the WWTP renovation project, a brand-new building was built specifically to treat phosphorous. Phosphorous was the main focus of the project, Goodhall said, but other mechanical upgrades were made to the existing buildings including new filters, disinfecting equipment and solar energy units.
Another issue, Goodhall said, is that sediment in the river contributes to the phosphorus levels as well, especially near the dams. It is not clear, he added, if it is cost-effective to try to remove that sediment.
A ribbon-cutting ceremony will be held at the WWTP on a date sometime this spring.