Murfreesboro pivots 2025 sewer rehab scope to address premature ductile iron pipe liner failures

Murfreesboro pivots 2025 sewer rehab scope to address premature ductile iron pipe liner failuresThe utility is partnering with local developers to install cured-in-place pipe (CIPP) liners inside newly laid ductile iron mains after mishandling led to cracks in the factory-applied lining, exposing the iron to corrosive sewer gases.

The Water Resources Board approved contract amendments to incorporate developer-funded warranty work into the city's 2025 sewer rehabilitation program.

Staff noted that cracks in factory-applied Protecto 401 liners allowed hydrogen sulfide to degrade the underlying iron, necessitating the CIPP intervention.

The scope changes also accelerate the replacement of failing pump station suction lines, which were losing prime due to severe hydrogen sulfide corrosion.

Despite the added scope, the construction change order with SBW Constructors decreases the total contract value by $2,844 to $4.33 million while adding 26 days to the schedule.

The City of Murfreesboro Water Resources Department is modifying its 2025 Sewer Rehabilitation Project to address premature corrosion issues in both newly installed developer infrastructure and existing municipal pump stations. During a June 23 meeting, the Water Resources Board approved contract amendments to tackle failing factory liners in newly laid ductile iron sewer pipes. According to staff, the pipes were specified to include a Protecto 401 liner. However, mishandling during installation by developers has caused the liner to chip or form cracks. "That crack in that liner... the hydrogen sulfide from the sewer will get into that crack and eat away at the iron below that liner," a staff member explained to the board. To resolve the warranty issue, the utility is stepping in to install cured-in-place pipe (CIPP) liners over the damaged sections. The developers are fully funding their portion of the repairs, but the utility is coordinating the work through its existing municipal contract because it is more cost-effective than developers mobilizing a lining contractor independently. The board approved a $31,436 task order amendment for LJA Engineering to provide construction administration for the added scope. Additionally, the utility is using the rehab contract to expedite emergency repairs at several municipal pump stations. Severe hydrogen sulfide corrosion has eaten holes through the suction lines connecting the pumps to the wet wells. The damage has caused stations, including the Thompson Lane facility, to lose prime, forcing the utility to initiate bypass pumping. The utility decided to pull the suction line replacements out of a separate, longer-term pump station improvement project currently being designed by SSR. By adding the replacements to the active 2025 rehabilitation contract held by SBW Constructors, the city hopes to prevent further operational failures. Through a series of quantity adjustments and the removal of other items, the change order for SBW Constructors ultimately decreases the total construction contract by $2,844, bringing the revised total to $4.33 million, while extending the project timeline by 26 days.