After flooding, MMSD considers checkups for sewer laterals

[excerpted from JS-Online.com]
by Don Behm

Call it a routine seweroscopy.

It is time to check the inner workings of private sewer laterals, say officials at the Milwaukee Metropolitan Sewerage District.

Cameras would televise the inside of 6,000 laterals in the next 12 months in a search for cracks or other damage allowing excessive volumes of storm water to enter municipal sanitary sewers, as part of contracts to be considered Monday by the district's commission.

During heavy rains, flows of storm water into laterals draining to sanitary sewers quickly fill the municipal pipes and cause overflows and basement backups, MMSD Executive Director Kevin Shafer says in documents distributed to the commission.

In the wake of catastrophic flooding on July 22, Shafer and several municipal officials at a public meeting in Glendale last week emphasized the need to reduce leaks of storm water into private laterals as part of any strategy for preventing sewage backups. Laterals extend from homes to municipal sewers beneath streets. Shafer has proposed spending $150 million in the next 10 years to inspect and repair private laterals in the 28 communities served by the district. The commission will discuss the plan later this year as part of the 2011 budget process.

On Monday, the commission will be asked to take a step down that path by awarding five private sewer inspection contracts, at a total cost of nearly $3.85 million, to Chicago-based National Power Rodding Corp. The company was the low bidder for each contract, records show.

MMSD would pay full costs of each inspection, under the voluntary program.

The contractor would televise and clean each lateral, cut and remove tree roots and note all defects, said Tom Zimmerman, MMSD engineering design and construction manager.

Possible leaks could be tested by pouring color-dyed water onto a lawn and checking whether it flows out of the lateral, he said.

Municipalities can choose whether they want to participate in the program, Zimmerman said. If they do, each community will be asked to identify priority neighborhoods, such as blocks where basement backups have been recurring problems.

"Our goal is to begin immediately," Zimmerman said.

Inspections of laterals would not be done, however, without the permission of property owners.

There are thousands of additional private laterals in the 28 communities - a total length of 3,000 miles of private sewers. Wauwatosa and a few other communities have started inspecting limited numbers of them, Zimmerman said.

Part of the costs of repairing problems disclosed in the inspections might be funded through the proposed $150 million leak prevention effort, Shafer and other district officials have said. The district likely would distribute funds to communities so local officials could reimburse property owners.

Leaking private laterals are the weak link in the regional system of collecting and treating wastewater, according to Shafer.

In addition to cracks or collapsed laterals, storm water can enter sanitary sewers where rooftop downspouts are connected to a lateral. And homes built before 1954 were allowed to connect exterior foundation drains to a lateral.

Leaks of water into sanitary sewers have increased since the district's deep tunnel system began operating in 1994, Shafer said. The excess water compromises the system's ability to store wastewater and prevent combined sewer overflows.

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To read Milwaukee Riverkeeper's Executive Director's recent op-ed regarding our local sewage infrastructure click here.