One Line at a Time

A small city in Minnesota meets the challenges of an aging infrastructure with a mix of rehabilitation technologies and aggressive public education

You wouldn’t depend on an 85-year-old toaster or furnace in your home, so why rely on an 85-year-old water or sewer line?

That’s a question that Joe Haller, public works director for Annandale, Minn., often asks residents of his small city, where his department is replacing or lining old water and sewer pipes. Some date back to the sand-cast variety installed in 1922.

Haller’s team began rehabilitating portions of Annandale’s 32 miles of water and sewer lines in 2003. He estimates it may take up to 10 years to complete the project, since funds are not always available and the community’s leaders and citizens must be educated about the need to update its infrastructure.

“Those are our biggest challenges,” he says, “financing and public education. Compared to that, laying pipe is nothing.” The city is rehabilitating its systems using a combination of trenchless and traditional methods.

Lots of water

Annandale lies 50 miles northwest of Minneapolis-St. Paul, and 30 miles from St. Cloud. The community has a strong downtown retail corridor, modern industry, and beautiful residential areas, including lake and golf course living. With 26 area lakes within a 10-mile radius, Annandale bills itself as “The Heart of the Lakes.”

Sand-cast pipe makes up about 25 percent of the city’s water lines, and much of it isn’t even round anymore, according to Haller. The remaining 75 percent is either ductile iron or PVC, installed in the 1970s. While age is a factor with the water lines, the area’s high water table presents problems for the city’s clay and PVC sanitary sewer pipes.

“In some places, our water table is only 4- to 6-feet deep, and our sanitary lines actually run below it,” Haller says. “With 4-foot sections in the clay pipe, it acts more like drain tile.” That has led to a serious infiltration and inflow issue at the 250,000-gpd wastewater treatment plant, which has been operating at full capacity.

The water and sewer line rehabilitation project has helped alleviate the situation. As Haller’s crew tightens up the system, less clear water flows to the treatment plant, freeing up capacity. That’s important because until recently the city was under a court order pro-­hibiting the construction of a new regional wastewater plant in cooperation with neighboring communities (see sidebar).

“Overall, we’ve reduced flow by about a million gallons a month, or about 25 percent,” Haller reports.

One step at a time

The first step in the rehabilitation project was to inspect all the sewer lines. In 2003, Haller and staff video-inspected the system under a contract with Infrastructure Technologies Inc. (Infratech) of Rogers, Minn.

The project identified sections of the system most in need of attention based on age of pipe, depth in relation to the water table, and history of problems. Haller’s team then coordinated repairs or replace-ments with the city’s capital street improvement plan.

The infrastructure project began the next year, starting with replacement of the sand-cast water lines, and lining of sections of the 35-year-old clay pipe sewers where street reconstruction and curb-and-gutter replacement was already scheduled. Lametti & Sons Inc. of Hugo, Minn., used cured-in-place pipe (CIPP) lining technology on the clay pipe that was still in decent shape. Pipe not suitable for lining was replaced by conventional methods.

Annandale also restored nine manholes using the Monoform system from Infratech. The process uses a plastic forming system to enable the pouring of high-strength, ready-mixed concrete to create a new monolithic structure within the existing manhole.

Because of funding issues, no improvements took place in 2005. But in 2006, the city totally reconstructed 13 blocks of water, sewer and storm sewer line, as well as force mains and utilities. Again, Lametti & Sons lined the 35-year-old clay pipe that was in good shape. In one four-block section, old sewer lines were as much as 10 feet below the water table. The town also replaced a number of corroded hydrants and rehabilitated 14 manholes. Key Contracting of Fargo, N.D., applied the CuraFlo Spincast method of centrifugally applying the coating to the interior manhole surfaces. The total cost of all 2006 projects was $3.2 million. A lack of funds again prevented work in 2007.

This year, working with general contractor Mid-Minnesota Hot Mix Inc. of Annandale, Haller’s team is reconstructing a seven-block section of street and sidewalk, curb and gutter. They are using the opportunity to replace old sanitary sewer line with 8-inch PVC, and water line with 8-inch ductile iron.

The project also calls for new reinforced concrete storm sewers where the line runs beneath road surfaces, as well as HDPE pipe elsewhere. The storm sewers are 12, 18 and 24 inches. Minnesota Pipe and Equipment of Farmington, Minn., is supplying the pipe, and the pipe contractor is Kuechle Underground Inc. of Kimball, Minn. These projects will cost about $1.2 million.

Educating the public

Haller firmly believes an educated public will support necessary infrastructure repairs, so he makes sure his utility has a booth at the annual business expo. There and at other venues, his staff displays a cross section of street to show residents how sewer, water and utilities work beneath the surface to keep the town running smoothly, and why 85-year-old infrastructure needs to be replaced and upgraded.

The Annandale Web site also displays a map of the street and water-sewer line reconstruction projects so homeowners can find out where work is scheduled and track progress. Finally, Haller makes sure his staff is up-to-date with the latest information so they can communicate effectively with homeowners as they replace meters.

“Most of our folks are receptive to the idea,” he says. Financing the projects is the other major challenge. “The longer we wait, the more emergency repairs we have to do, and then possibly do them over again,” says Haller. “It’s better to reconstruct if possible.” He says homeowners who need emergency repairs pay about $5,000 for the new service and associated street repairs. His crew performs five to 10 “curbstops” every spring as the frost moves out.

“It’s not just the cost to do a project, there’s a cost not to do it,” he says. “We try hard to educate people on the cost of not doing anything.” If Haller needs proof that the rehab program in Annandale is worth it, he can point to community development.

With a maxed-out wastewater treatment plant and government limits on pollutant loads, the only way the town has been able to grow these last few years has been by fixing its underground infrastructure. “We’ve enabled the town to continue to expand,” he says, “and we’ve bought time.”


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