New Berlin - The city is about to embark on a project that could save New Berlin homeowners thousands of dollars.
It's the private property infiltration and inflow program where the city offers to line leaking private sewer laterals, a $6,000 to $8,000 job the homeowner wouldn't have to pay for. Laterals are pipes that take waste water from homes to sewers underneath streets.
Eventually, the laterals crack and leak and in some cases collapse, resulting in sewage backups into basements. Lining a lateral is a way to basically give 50-plus years of service from what is virtually a new pipe, said Chris Stamborski who is heading the project. Stamborski is associate assistant director of municipal services for R.A. Smith National, Inc. of Brookfield,
The city and the Milwaukee Metropolitan Sewerage District are interested in the city's pilot sewer lateral lining program because they want to reduce the amount of rain water that gets into the sanitary sewers. Rain soaking into the ground reaches the holes in laterals the flows into them and eventually into sewers.
During severe storms, sewage treatment facilities and the New Berlin sewer system can't keep up with the torrent of sewage that comes through and dump the diluted sewage into Lake Michigan, into rivers and in the city's case into ditches. That is the only way to keep sewage from backing up into homes.
The last time New Berlin had to dump diluted raw sewage was the August 2008 storm that caused severe flooding throughout the region, said James Hart, utilities department manager.
The Forest View subdivision, one of the city's oldest, was chosen for the city's pilot project. It not only has many leaky private laterals, but it will be easy to measure sanitary sewer flows before and after the project, Stamborski said.
"Then we can determine if it was worth it," he said.
New Berlin, like other communities, is trying to find the most cost-effective way to deal with private laterals pouring rainwater into sanitary sewers. Although New Berlin doesn't have a big problem with that now, it is being proactive, Stamborski said.
Why Forest View
"Collectively, Forest View is one of the worst," he said in terms of leaky laterals. "Individually, lateral by lateral, it is not one of the worst. We're coming for the worst next."
New Berlin has received $1 million from the MMSD for the pilot program. The grant is actually money that New Berlin's utility rate payers have already paid into the MMSD for projects to reduce inflow and infiltration of rain into New Berlin sewers.
The Forest View subdivision rehabilitation area is between Elm Grove and Sunnyslope roads and from about the New Berlin Recreation Trail to north of Ferguson Drive. Homeowners will be asked if they want the lining and to give permission for crews to come onto their property.
Although the laterals can be lined from inside the sewer in the street without digging the lateral up, crews do need to dig a square foot hole near the house down to the lateral. There they will lower a camera so that they can watch the procedure to be sure everything is happening as it should, Stamborski said.
When the lateral is lined, the crew will install an access pipe, the hole will be filled back in and a slab of sod will be put over the hole or the one square foot will be restored as it was before. Stamborski emphasized that no backhoes or heavy machinery are used to dig the access holes. The restoration may have to wait until all the laterals in the subdivision are lined, which could take two or three months.
The lining process uses a remote-controlled launching device. It has a camera in front of it so the operator watching a television screen up top can see what's happening and it has wheels underneath it. The launching device drags behind it a felt bag that's as long as the lateral. The bag that can be thought of as a sock has been soaked in the resin that will react with heat that will cover the inside of the existing lateral and then harden into a new lateral, only with no cracks or breaks.
The launcher also drags along a hose for water or compressed air that it will use to literally turn the sock inside out. The "sock" is inside a bag that is pressurized with the water or air that pushes the sock out into the lateral. Once out, the resin is activated with steam or hot water.
After the process is successfully completed, the camera is pulled out of the hole near the house and an access pipe is installed. Then the hole is filled and later restored.
On a good day, a crew can do two or three homes, Stamborski said.