City of Lawrence investigates Maplewood sewage overflow


The sewage system at Maplewood Mobile Home Park off Pendleton Pike has been overflowing during rainy weather, creating drainage concerns for the City of Lawrence. As part of its ongoing sewer rehabilitation program, the city recently completed an investigation into that privately built sewage system.

The resulting recommendation is a complete replacement of the system, which would cost the park’s owners upwards of $6 million. Maplewood owners are looking into less costly alternatives, according to city officials.

Contractor American Structurepoint conducted the city’s investigation, which included cleaning out pipes and taking video of the interiors to assess their conditions. During a utility service board meeting, Project Manager Karen Saavedra said they already knew there was an issue, because of sewage rising up in manholes during rainy weather.

Saavedra said they tried to start with a smoke test, which helps establish where cracks are located, but that didn’t work. Some manholes in the park are located directly under trailers, so they couldn’t get the equipment in place. They also tried flushing pipes to get clear video of the interiors, she said. It wasn’t as successful as they hoped because it started to create backup in some residents’ toilets.

Saavedra said they were able to complete their investigation on about half of the system. She noted that problems found in the parts they were able to access likely are the same throughout the park’s sewer system.

Those problems included grease buildup and roots from plants that found a crack and grew into the pipes seeking water. Both create blockages within the pipes.

“The problem with all these blockages is then when we add extra flow from rain plus the sewage, the sewer doesn’t have enough capacity because its blocked,” she said, which leads to overflow.

One option for fixing these kinds of problems is cured-in-place pipe, or CIPP. That’s essentially a new pipe that’s inserted inside an old pipe. Saavedra said that is the least expensive option, but likely wouldn’t work in this situation because of inaccessible manholes.

The recommended option instead is a completely new sewage system.

“It’s not the cheapest solution, but we feel like in this scenario it’s the only choice that makes sense,” she told the board.

The engineer’s rough cost estimate for a new sewage system is approximately $6 million.

Lawrence Utility Superintendent Scott Salsbery said he and other city officials met with Maplewood owners to provide raw data from the investigation and to talk about the report. In an email, he stated that he also gave the city’s recommendation, but the owners will have their own engineers look at the information. He said the owners also noted that off-site drainage from neighboring developments is adding to the problem.

“I reiterated that the only concern Lawrence Utilities has is the significant amount of rain and groundwater entering the system during rain events,” he stated. “But we also made sure they understood that we are reaching out to them in a spirit of cooperation and will work with them, but we must see progress.”

Salsbery said that because it is a private system, it is ultimately up to them to resolve the problem. He added that the city would provide technical assistance and would meet with the park’s owners regularly.