One mission of Darin Severson, supervisor for the utility and repair division for the city of Naperville, Ill., is to completely eliminate leaks from its collection system. “The city council demands that we keep the collection system performing, even during heavy rains,” he says.
Charged with maintaining more than 10,000 sanitary manholes and in excess of 300 miles of pipe, Naperville has developed a progressive preventative maintenance program. According to Severson, the tops of the manholes are one of the first parts of the collection system to fail. In many parts of the country, the tops need to withstand freeze-thaw forces and heavy loads from traffic. Top it all off with a highly corrosive environment, and the structures break down very quickly.
Failure at the top of manhole structures is costly. Premature damage to the surrounding pavement, the need to repave the road due to a sunken manhole, and other factors lead to the need for significant repairs. Perhaps the most costly result of failure is the excess water entering the system, which eats up capacity and significantly increases the likelihood of overflows.
The Lifespan System—from Fairfield, Conn.-based CWR Holdings LLC—is a frame cover and adjustment system designed to ensure manhole tops retain their structural integrity and remain leak-free. The product has been installed in several Canadian cities, where it continues to perform well even after years of heavy snowplowing and vehicle traffic.
The fully integrated, structural solution is made from ultra-high-performance elastomers (UHPEs). It consists of a UPHE frame, UPHE-tapered adjustment risers, a cast-iron cover with cams, and all accessories needed to facilitate simple, worry-free installation. The system design and UHPE construction minimize inflow between the frame and cover. Also, because the area below the frame is constructed with watertight, flexible, yet sturdy materials, they are able to absorb dynamic loads, minimize road noise from rattling covers, and reduce infiltration.
The Lifespan System is also simple to put in place, according to Jack Callahan, vice president of Kenny Construction, Wheeling, Ill., a company that installs the product. He adds that “the frame weighs about 65 pounds, so from a worker-safety perspective, this is a big improvement regarding safety and performance in general.”
Severson says the Lifespan System is the “smartest” product for the type of manhole structures that he's come across. “We never want to go back to a structure we have already fixed,” he says. “Lifespan will allow us to do the job right the first time and have it last.”
— David Sinclair and Paul Keblish are co-founders of CWR Holdings LLC.