Westfield, MA, February 11, 2009 – The American Council of Engineering Companies of Connecticut presented Tighe & Bond and the Aquarion Water Company of Connecticut with an Engineering Excellence Grand Award for the Palmer Dam Rehabilitation / Dean’s Mill Water Treatment Plant Improvements project. The award was presented at an association dinner at the Inn at Middletown recently. Westfield, Massachusetts-based Tighe & Bond provided engineering and construction phase services for the $18.5 million project, which was constructed by Daniel O’Connell’s Sons of Holyoke, Massachusetts.
When Aquarion Water Company of Connecticut acquired its Mystic System in 2002, the firm inherited a CT Department of Environmental Protection (CTDEP) consent order requiring repair of the Palmer Dam. Corrective measures were mandated because the dam’s spillway could not safely pass the volume of water projected in the event of flood conditions. Furthermore, the dam was determined to be in poor condition and considered unstable in an overtopped situation. Failure of the 500-foot long, 34-foot high structure originally constructed in 1929 could have been catastrophic. Aquarion retained Westfield, Massachusetts-based Tighe & Bond to engineer the Palmer Dam repairs because they proposed a cost effective and innovative approach to solving the problem.
The Palmer Dam impounds 88 million gallons of water in a reservoir which serves as one of two supply sources for a population of over 10,000. Tighe & Bond was already working on improvements for the Dean’s Mill Water Treatment Plant on the site, and designing and constructing the $18.5 million in improvements together offered economies of scale and facilitated seamless coordination. The most significant result of completing the rehabilitation of the Palmer Dam in May 2008 is enhanced public safety. The integrity of the Palmer Dam is no longer in question and area residents can rest assured.
Design and construction of the improvements presented a number of interesting challenges, including the need to maintain undiminished operation of the active public water supply reservoir and the treatment system at all times. Tighe & Bond was able to adapt and design “on the fly” during the construction phase of the project and keep pace with the expedited schedule. The new chemical building cast integrally into the southern face of the dam added a level of complexity to the project but provided a space conscious and sustainable design. Great measures were taken during construction to protect water quality without interruption of service.
Tighe & Bond recommended using adjustable crest gates, a unique and cost effective application of an age-old technique, in repair of the Palmer Dam. Electrically-operated crest gates were installed to increase the reservoir’s spillway capacity, providing a method of maintaining the desired storage volume and spillway flow, without the need to raise the physical dam structure elevation significantly. An ingenious sequence of operations was developed and successfully negotiated with the CTDEP.
A permanent secondary containment area was constructed to protect the environment in the event of an accidental release from a chemical truck or hose during deliveries to the Dean?s Mill water treatment plant. This is not standard practice at water treatment facilities; portable enclosures are much more common as they are less expensive. Although it cost a bit more, Aquarion chose to “raise the bar” and implement these measures proactively.
The cooperative nature of the relationship between the engineer, owner, contractor and regulators was a key to the project’s success. “This project was the smoothest and most efficient I have experienced in my 20 year career,” comments Judy Simpanen, Manager of Aquarion’s Mystic Operations. “I have received countless compliments on the practical, attractive, and cost effective design. Tighe & Bond has given us a finished product of which we can be proud.” Aquarion’s proactive improvements advance public health, enhance public safety and protect the environment, and serve as a model for other waters suppliers and dam owners.
Founded in 1911, Tighe & Bond is one of the most experienced engineering firms in New England, with offices in Westfield, Worcester and Pocasset, Massachusetts; Danbury, Middletown and Shelton Connecticut. Tighe & Bond is annually ranked among the top design and environmental engineering firms nationally by the Engineering News Record and was recently named as one of the top 50 “Best Civil Engineering Firms To Work For” in the nation by CE News. The firm provides engineering and environmental services for clients in government, industry, health care, education and real estate development.