Water and Sewer Projects
2021 WATER MAIN IMPROVEMENTS, CONTRACT NO. 7
Project Description:
The work of this Contract includes construction of new water main in the City of Melrose. The majority of the work is scheduled between July and October of 2021. The Contractor for this project is R+D Site Development. The Department of Public Works will have an engineer on site at all times during active construction.
The work consists of installing approximately 1,800 linear feet of 12-inch ductile iron water main and 3,000 linear feet of 8-inch diameter ductile iron water main on Pleasant St., Brazil St., Burnett St., Hunnewell St., Sycamore Rd., Felton Pl., and Ashland St. All water mains shall be furnished and installed with associated valves, fittings, and hydrants. Temporary bypass piping shall be used during the construction of the water main where specified. All service connections are to be replaced from the main to the property line after the water main successfully passes the pressure testing and chlorination procedures. Pavement restoration will occur in Spring 2022.
WATER – UNIDIRECTIONAL FLUSHING PROGRAM
Project Description:
The City’s Unidirectional Flushing Program is conducted as part of the DPW’s maintenance and asset management effort. This investigation will be completed to collect data on hydrant flows, volume and clarity of water flushed, recorded water pressures, and fire flows. Modifications to the GIS files will be completed, as necessary. A summary report will include data tables from each flushing sequence from 2017, 2019, and 2021 for historical comparison, an estimate of the amount of water used during flushing based on recordings of the flow rate and flushing duration, and a list of hydrants and valves to be repaired or investigated.
Infiltration and Inflow Removal Program
In 2016, the City began addressing infiltration and inflow (I/I) in the sewer system by conducting a City-wide flow metering program. Thirty meters were installed for 10 weeks and the data collected has been used to prioritize the subareas with the highest I/I rates and develop a program for rehabilitation of that infrastructure. Infiltration is clean groundwater that enters pipes through cracks. Inflow is surface water or rain that enters the system through direct connections (e.g., sump pumps) or through defective manholes or covers. I/I is clean water that does not need to be treated at a wastewater treatment plant. I/I in the sewer system costs the City money and can cause backups due to capacity problems.
The City has 74 miles of sewer mains. A multi-phase program is underway to identify sources of I/I. Investigations to find infiltration include flow isolation, CCTV of pipes, and manhole inspections. Investigations to find inflow include smoke testing, dye testing, and building inspections. Rehabilitation methods include cured-in-place-pipe (CIPP), short liners, manhole sealing, and complete pipe replacement. To date, the City has CCTV investigated approximately 57% of the City’s sewer mains and 500 manholes. The investigations have resulted in the following rehabilitation projects: CIPP lining of over 50,000 linear feet (LF) of pipe, replacement of 1,200 LF of pipe, and rehabilitation of 19 manholes. To date, over $9 million dollars has been spent to identify and remove I/I in the City. This work is funded through a grant/loan program provided by the MWRA.