- Removal of 35-foot tall dam – the tallest ever removed in Massachusetts
- Staged dam removal throttled the release of about 10,000 cubic yards of “clean” sediment to downstream sediment starved reaches
- Designated as a Priority Project by the MA Division of Ecological Restoration (DER)
- Secured grant funding from the EOEEA Dam and Seawall Repair and Removal Fund in the amount of $633,996 or about 75% of the construction costs
Faced with an Office of Dam Safety Order to repair the dam or take it down, the City asked GZA to identify the most cost-effective approach, provide design plans, obtain necessary permits, and act as the resident engineer during construction. The earthen dam with a stone masonry spillway is an approximately 35 feet tall and 125 feet. This High Hazard, former water supply dam had been in a Poor/Unsafe condition since the 1970’s.A dam breach would require tackling the issue of dealing with approximately 27,000 cubic yards of sediment impounded by the dam.
The City concurred with GZA’s recommendation for dam removal as the preferred alternative. Connecting high-quality trout habitat in the stream above and below the dam made the project a priority for MA Division of Ecological Restoration who eventually became a project partner. After years of meetings and deliberations with city residents and regulators, the City, with the help of GZA and MA DER, was able to obtain concurrence to permit the project as a staged dam removal with a controlled sediment release. The project approach was developed to “throttle” the release of about 10,000 to 11,000 CY of sediment to the downstream sediment starved reaches. A post-construction sediment survey completed in the early fall of 2018 revealed very good agreement with GZA’s design, specifically, the amount of sediment mobilized (about 10,800 CY) and the location of the newly formed stream within the former impoundment.
Practitioners from multiple GZA core service areas comprehensively and successfully addressed the City’s engineering, permitting, and construction support needs for the project. GZA also was successful in securing an EOEEA grant to cover 75% of the construction costs. The City’s liability was reduced by removing the Poor condition, High Hazard dam which also resulted in the removal of the tallest dam removal in Massachusetts. Project costs were reduced by using the innovative sediment release approach in lieu of dredging/offsite disposal, saving the City nearly $500,000. The newly formed stream re-established the connectively between two high-quality cold-water fishery habitats.
Am I At Risk of Vapor Intrusion?
In this interactive ebook, David Schultz and Michael Zazzera explain what vapor intrusion is, how it happens, and possible mitigations.
Case Study: Hennepin County Environmental Response Fund (ERF) Contamination Cleanup Grant
The Debra Selam Orthodox Church, a minority-owned non-profit, holds a 2.67-acre property in the Seward Neighborhood of Minneapolis, Minnesota. The property was initially developed in the 1900s with...
EPA Amends All Appropriate Inquiries Rule to Add New ASTM Standard
On February 13, 2023, a new rule issued by the US Environmental Protection Agency (EPA) goes into effect that amends the All Appropriate Inquiries Rule (AAI rule 40 CFR Part 312) to reference ASTM...
New Lead Paint Regulations: Costs, Paperwork & Questions
In the December 2022 issue of Commerce Magazine, Benjamin Sallemi, Ph.D, CIH is interviewed on the impact of new state regulations on lead-based paint in New Jersey.