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Our Aging Infrastructure
Part 2: Trying to Keep Pace with Water System Needs

Our first article examined the need for infrastructure renewal on a national level. We are now turning to water infrastructure needs within the Detroit Water and Sewerage Department (DWSD) service area. The DWSD water system serves nearly four million people in 127 communities with water produced at five water treatment plants operated by DWSD. The treated water is pumped through large transmission mains to connections in suburban systems where the local communities operate and maintain the distribution system that delivers water to residents’ taps.
 
To learn more about local challenges of maintaining our water system, we talked to professionals with Livonia, Rochester Hills, Taylor, Madison Heights, Harrison Township and the DWSD. While each community faces a unique set of challenges, the overall themes are consistent with what is being experienced on a national level. Aging pipes can only be replaced as quickly as budgets allow, operations and maintenance staffs continue to shrink, water use continues to decline, and greater public support to reinvest in our infrastructure is needed. On the positive side, communities are joining forces to reduce project costs, using new technology in rehabilitation projects, and leveraging funding to maximize investment. This article presents a snapshot of how area water professionals are maintaining water services while stretching budgets and getting by with fewer resources.
 
Piggybacking Projects and Joining Forces to Reduce Reinvestment Costs
Road reconstruction and water main replacement projects frequently go hand in hand. If a road will be torn up, it makes sense to replace the water and sewer pipes underneath at the same time. As part of its prioritization process, the City of Livonia looks at which roads are slated for repairs to determine if utilities should also be rehabilitated or replaced. This includes road reconstruction projects undertaken by other entities like the Michigan Department of Transportation (MDOT).
 
This fall, several months before I-96 is closed for reconstruction, the City of Livonia will begin relining sanitary sewers from manholes in the service drive to get a head start on the process. “We have been working with MDOT to coordinate the rehabilitation of 33 utility crossings during reconstruction,” explains Don Rohraff, Superintendent of Public Services for Livonia. “These are the original pipes that have been there since the freeway was constructed more than 40 years ago.”
 
Lining the sewers first enables the more intense work of water main lining to begin once the five-mile stretch of I-96 within Livonia’s borders is closed. “Lining the water main requires excavating in the shoulder of the freeway,” Rohraff continues. “Two of the mains are 30-inch transmission mains that feed other water mains increasing the complexity of construction. It is safer and more cost-effective to do the work when the road is closed.”
 
Savings are being realized by constructing the project at the same time as MDOT – maintenance of traffic plans and signage are not needed. A shared construction contract was also developed with Redford Township that contains a two-mile stretch of the freeway’s reconstruction to obtain better lining pricing through economies of scale.
 
Aging cast iron pipes are being replaced as they reach the end of their useful life. Tuberculation in older, unlined cast iron pipes (above) weakens the pipes making them more prone to breaks. Newer pipes are lined to prevent internal corrosion. Limited budgets and funding sources are slowing the pace of reinvestment in many communities.
 
 
 
 
 
Addressing System Components with the Greatest Need and Using New Technology
Water main breaks frequently drive replacement projects as well. Cast iron corrodes over time, weakening the pipe and making it susceptible to breaks and the freeze-thaw cycle brings ground movements and increased breaks. The number of breaks a community must repair in a given year is dependent on the age of the pipe, pipe material and size of the community.
 
While Livonia has rehabilitated most of its 1920s pipe, much of the original cast iron pipe installed in the 1950s and 1960s remains in service. With a 36-square-mile service area containing 484 miles of water main and a lot of aging cast iron pipe, the Department of Public Service repairs about 180 breaks each year. The number is much lower in Rochester Hills, a 32-square-mile community where only 4% of their 420 miles of water main was installed prior to 1970. They typically only experience about 10 breaks a year but the age of older mains is starting to show. The majority of mains that do break are cast iron that was used until the mid-1970s when ductile iron, a stronger material, became the preferred choice for water main.
 
“We need to replace a one-mile segment of 8-inch cast iron water main along South Boulevard, our border with the City of Troy,” explains Tracey Balint, Public Utilities Engineer for Rochester Hills. “The right-of-way is really congested with other utilities so we reviewed different construction methods to determine the best approach to minimize displacement and impact on adjacent infrastructure. We also wanted to increase the pipe diameter based on the size of connecting pipes. We determined that pipe bursting was the best solution.”
 
 
Article continued on page 2
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