MMSD Sewer System Rehabilitation
MMSD Regent Street Sewer Lining
The original West Interceptor was constructed in 1916 and is one of the District’s oldest facilities in the collection system. The sections of this pipeline scheduled for rehabilitation consist of approximately 4,425 feet of 24” cast iron pipe located in N Randall Ave. from W Dayton Street to Regent, in Regent Street from N Randall to East Campus Mall, and in a sanitary sewer easement from Regent to a point 700 ft. south of Regent Street. The manholes in North Randall Avenue are located near the center of the south bound lane. The manholes in Regent Street are located near the center of the two west bound lanes. The primary defect in the cast iron sewer is tuberculation, which is the buildup of mineral deposits on the inside walls of the pipe due to chemical reactions between the wastewater and the cast iron pipe. The deposits generally form above the normal waterline and their effect is to decrease the carrying capacity of the sewer by reducing the effective diameter of the pipe and increasing the surface roughness. Removing the tuberculation and lining the pipe will make the pipe less rough, improve its flow characteristics and prevent further tuberculation. The project will include pipe cleaning utilizing a drag scraping method, installation of a cured in place pipe (CIPP) lining, bypass pumping and pavement restoration. Removal of existing manhole top decks is required to provide access for the drag scraping process. Drag scraping will be done in five sections, and lining will be installed in nine sections with cleaning and lining proceeding as a consecutive, continuous process.
Lining rehabilitation has significant advantages with regard to environmental, social, and transportation impacts. Installation of a new sewer with standard excavation methods would cause significant disruption to local businesses and vehicular traffic. These effects will be greatly mitigated through rehabilitation, which does not require extensive excavation of the street and enables smaller works zones to be utilized.
The work requires pipe cleaning and pipe lining equipment located in the street. Some excavation is required to provide access to the underground pipes. Sewage flow must be bypassed around the pipe being rehabilitated. Pumps and bypass pipes will be located above ground in the Right of Way. Limited restoration of street pavement will follow completion of the pipe lining. Residents and businesses can expect intermittent parking restrictions and lane closures along Randall Avenue, Regent Street, and Park Street, as well as closure of some ancillary streets. Lane and/or street closures will vary by section as construction by section proceeds. Changes to traffic control will be preceded by electronic message notification signs. Much of the work will occur during nighttime hours.
Properties located along the north side of Regent Street and most of the properties along N. Randall Avenue will experience limited interruptions of sewer and water service. Residents will receive notification 48 hours prior, and should expect service interruption up to 12 hours duration.
Notice to Proceed is anticipated to be February 27, 2017. Work in right of way is expected to begin April 3, 2017. Substantial completion (All work complete) is June 30, 2017