More NEI Replacements Needed
Wilmington, NC – Wilmington officials announced Thursday that 1400 more feet of the Northeast Interceptor sewer line need to be replaced.
The nine-mile line is already undergoing major repairs required to lift a state ban on new sewer permits. That work is expected to be complete in January.
While working on an underground vault, crews recently discovered that a segment of the line near the Cameron Art Museum uses a type of PVC piping that insn't approved for the higher pressure sewer flows planned for the line.
Project manager Chris Bowling says the pipe isn't corroded in any way; it's just not strong enough overall.
This type of pipe, because it's a lesser pressure rating than what we want, we would not want to turn on those higher-pressure interim pumps until this segment was replaced.
City records show the PVC piping was installed in the wake of a spill on the line 18 years ago, according to Bowling, who says he doesn't believe this type of pipe was used anywhere else in the line.
"We do have people who were working here in that time period, and from their recollection, they don't recall any other PVC pipe that was of this type that was used."
Poor record-keeping after past repairs has been an ongoing problem for the NEI. An undocumented patch was blamed for a major spill near Hewlitt's Creek last November.
Bowling said he doesn't believe this section of the NEI was incuded in the recent inspection of the line because engineers looking for corrosion weren't worried about the plastic piping.
The weaker grade of PVC is only detectable by visually inspecting the pipe.
Bowling says he doesn't have an estimate yet for how much replacing the line will cost, but says it shouldn't slow down the overall repairs to the NEI, which are scheduled to wrap up in January.