To:
From:
Re:
C. Motion:
Discussion:
City of Nashua, Public Works Division
Board of Public Works Meeting Date: August 25, 2022
Daniel Hudson, P.E., City Engineer
Engineering Department
2022 Sewer Siphon Rehabilitation Construction Services
To approve the construction administration contract for sewer siphons
rehabilitation with Hazen and Sawyer, PC of Manchester, NH in an amount of
$192,876. Funding will be through Department: 169 Wastewater; Fund: Bond;
Activity: Sewer Improvements.
Hazen and Sawyer was selected as the engineering consultant to complete Phase |
of the Capacity, Management, Operation and Maintenance (CMOM) program.
During that project, eight locations where inverted sewer siphons convey
wastewater from one side of a waterway to the other side were cleaned and
inspected using closed circuit television (CCTV). The siphons are comprised of 22
sewer sections totaling 4,700 feet in length, are made of various materials, and
range in diameter from 6 inches to 60 inches. The siphons were originally
constructed between 1965 and 1982.
Fourteen of the 22 sections in the siphons ranging in size from 8 inches to 36 inches
were identified with deficiencies that include cracks, erosion of cement lining,
corrosion, holes, and exposed rebar. Hazen provided the proposed design using
methods of pipe lining to rehabilitate the pipes and has the necessary expertise to
provide construction administration to ensure proper construction methods are
followed by the contractor.
