Residents urge prompt action on storm-related sewer backups
The next time extraordinary rainfall saturates Naperville, some basements likely will take on raw sewage, as they have in the past. City officials expect it to happen to fewer of them as time goes on, however.
Jim Holzapfel, director of water and wastewater utilities, is confident that a remedy planned for implementation in the coming months will especially insulate homes in two of the subdivisions hardest hit in last April’s floods from a repeat of that experience. About 250 residents reported sewage flowing into their basements after more than six inches came down on the city April 17 and 18, closing roads, bridges and schools for two days.
In the Cress Creek neighborhood on the city’s near northeast side, a high water table and substandard drainage hinder efforts to keep basements dry, Holzapfel said. The sanitary sewers will be more effective, he said, once they have undergone a high-tech lining treatment slated for some 10 miles’ worth of the clay line.
“We’re going out pretty quickly, in the next month or so,” said Holzapfel, who expects a contract for the anticipated $2.4 million project to be awarded in November, with the work to begin before the end of the year and last until spring.
The lining is made of a polyester felt material that is soaked with epoxy and soaked in warm water, which makes it adhere snugly to the inside of the piping. Holzapfel said installation goes best when the ground is frozen.
“It’s a trenchless technology, so we’re not digging anything up, or very little,” he said. “It’s minimal disruption to the community.”
Crews can line about 1,000 feet of pipe at a time, and it takes four to six hours for the material to fully cure.
“They can run a few thousand feet a day, once they get going,” he said.
Another area of the city saw sewage backups for different reasons. Many of the long and aging service lines in the Naperville Heights neighborhood have already been lined, Holzapfel said, but some still leak.
“The only thing we can think of is people are taking in water in their basements and it’s draining into the floor drains,” he said.
In that area, where many of the homes are without sump pumps, the city is offering to pay 75 percent of the cost for installing overhead sanitary sewers to keep the tainted water out of basements.
Because of the significant costs involved, a comprehensive long-term solution is not expected in the near future. Holzapfel said that makes the overhead systems the only viable route to relief right now for Naperville Heights.
“Until we get our system tightened up a little more, we think if you’ve had sewer backups, that’s something you should take a look at,” he said.
Big picture urged
Cress Creek resident Burt Thomas is among the residents who want to see the city address the flooding issues aggressively. Thomas blames the repeated sewage backups in his neighborhood on “outdated infrastructure and inadequate pumping ability.”
In an email, Thomas expressed doubt that the lining plan will fix the problem.
“There are no before-and-after measurements to gauge the effectiveness of this approach,” wrote Thomas, noting that officials have acknowledged that lining the full 600 miles of sewer pipe that comprise the system will take decades.
He and his neighbors would prefer a broader, faster approach.
“We’ve got to, as a city, do a whole lot more to address this problem,” said Dale Bryson, who told the City Council in June that his home has flooded five times in the 26 years since he moved in.
Holzapfel has faith that the lining contract for Cress Creek, which this year will double the sum the city normally puts into bolstering the sewer system, will be money well spent.
“We do monitor the flow in and out of the system. ... The hard thing is, every rain storm is different,” he said, adding that the city has metrics and trending data indicating the lining is effective. “Is it quantitatively, 100 percent right on? No. There is fluctuation, but we know the liner works. We know that.”
In some Cress Creek homes constructed at a time when builders thought “the sump pump could carry the day,” he said, the basement sits below the water table.
“I don’t know if there is a good answer for those guys,” Holzapfel said. “You have that a lot in Cress Creek, and I don’t really know what we can do with that.”
Countering criticism of the overhead sewer approach being used for Naperville Heights, he said no remedy is foolproof. In “a small percentage” of homes that install the system, he said, water could come in or could seep into the basements of adjacent homes that don’t have backup prevention.
“Doing nothing for fear that you’re going to affect someone else isn’t a good plan, in my opinion,” he said.
Many of the Cress Creek homeowners want the city to place high priority on addressing the recurring sewage backups.
“Cleaning up raw sewage in a basement is disgusting,” Bryson said.
Rob Neufelder, a 24-year Cress Creek resident, told officials his basement has been fouled by sewage three times, and wonders how common his experience is.
“I would like to see an outreach program from the city, to survey folks to see what kind of problem they’ve had in their basements,” he said.
According to Holzapfel, the near-term projects will bring relief. The lining program, he said, has already shown encouraging results.
“Our average daily flow to the treatment plant is less than it was 10 years ago, even though we’ve added 10,000 to 15,000 to the population,” he said.
The city’s sanitary treatment plant was scheduled for one more in a series of incremental expansions that would enable the system to process 36 million gallons a day. The final expansion is no longer needed, Holzapfel
said, because of the 100 miles of the system that have been lined so far.
“‘The lining program is working. There’s no doubt about it,” he said.
He is certain the city is on the right track.
“Naperville is probably one of the more aggressive communities in the nation in terms of lining the sewer system,” he said. “We have a little ways to go, but we’re chipping away at it, year by year.”