Monkey Run Interceptor Sewer Rehabilitation

Project Overview

The City of Jackson selected NTH to perform a condition assessment of the 4000 feet long, 60- to 66-inch diameter brick sanitary interceptor sewer between North West Avenue and West Trail Street in Jackson, Michigan. NTH utilized LimnoTech to perform flow monitoring and a hydraulics study to confirm the required capacity, which was utilized in the proposed rehabilitation options.

NTH and LimnoTech developed three rehabilitation options ranging from in-pipe repairs to total relining of the brick sewer system. The Engineer’s Estimate of Probable Repair Costs were calculated for each option along with a detail of impacts to the community during each of the repair options. NTH is currently working with the City of Jackson to design the most favorable option given the City’s available budgets and the criticality of the defects.

Project Scope

The City of Jackson requested a condition assessment and hydraulic analysis to determine the best repair options for a 4000 foot long, 60- to 66-inch diameter brick sanitary sewer. The initial design of the sewer was to convey combined sewer flow, but the storm water flow was previously separated, leaving the brick sewer with much greater flow capacity than required. The alignment of the brick sewer was a major consideration during the project as a section of the sewer system runs under a high school stadium and along a busy railroad Right-of-Way corridor. Therefore, a failure to the sewer system would be catastrophic for either of these areas.

The condition assessment included a closed-circuit television (CCTV) inspection along with an extensive review of existing records. The alignment included 125 sewer taps. However, a large number of these had previously been abandoned. A hydraulics study was conducted to observe the flows during normal dry weather conditions as well as during some wet weather events to determine the impact of storm flow on the sewer system and allow for proper resizing of the sewer pipe.

The data from the condition assessment and hydraulic study was evaluated and three options for rehabilitation were provided, along with estimated cost and impact to the community. These options included repair of the defects within the sewer system and maintaining the size of the sewer, slip lining the entire sewer system with a smaller diameter pipe to rehabilitate and properly size the sewer based on the flow characteristics, or a combination of both – slip lining under the critical infrastructure and repairs within the pipe at the other areas.

The NTH team is currently working with the City of Jackson to determine the best option to fit within the City’s available budget while providing the necessary sewer rehabilitation services.

Project Challenge:

The City of Jackson was concerned about the condition of an older, brick sewer that ran under a high school stadium and along a busy rail road Right-of -Way corridor.