ASAP Sanitary Sewer Interceptor Rehabilitation – NTMWD
The ASAP (Allen Sewer Association Partners, Inc.) interceptor was installed in 1985 and owned and operated by the City of Allen until a transfer of ownership to the North Texas Municipal Water District (NTMWD). This interceptor serves the cities of Frisco, Allen, McKinney, and Plano. NTMWD selected LAN to design rehabilitation of the ASAP interceptor utilizing the trenchless construction technology of cured-in-place-pipe (CIPP).
Improvements in the system included design for 17,650 LF of 27- to 42-inch CIPP, rehabilitation and coating of approximately 50 manholes. The pipeline had several challenging design elements, including one railroad crossing, two aerial creek crossings, five roadway crossings, and an existing manhole located in a private home owner’s backyard. The interceptor generally ran parallel to a natural channel (Rowlett Creek) and was located entirely in the floodplain. The alignment and required bypass piping during construction traversed through two golf courses (Chase Oaks and Twin Creeks golf courses) and two public parks (City of Allen’s Suncreek Park and City of Plano’s Oak Point Park & Nature Preserve), which required tree protection and mitigation and consideration for all construction.
The design of access and bypassing required coordination with TxDOT, DART, a privately owned tree farm, the golf courses, the Suncreek Subdivision homeowners association, the City of Plano, the City of Allen, private business owners, and private home owners. The project was constructed in two phases.
At a glance
- 4,885 LF of 27-inch diameter interceptor rehabilitation
- 9,338 LF of 33-inch diameter interceptor rehabilitation
- 3,710 LF of 42-inch diameter interceptor rehabilitation
- Rehabilitation and coating of approximately 50 manholes
- Construction and coating of two new manholes
- Carbon fiber technology was utilized to rehabilitate two aerial creek crossings
- Permitting was required with TxDOT and DART to coordinate bypass piping during construction
- Bypass pumping costs were minimized by using available capacity in a parallel pipeline to convey flow
- To minimize risk during construction, bypass pumping required a wet weather response plan and shutdown checklist
- Bypass pumping design
- Manhole rehabilitation design
- Manhole protective coating design
- Tree Mitigation Plan
North Texas Municipal Water District