28/Plumbing Engineer June 2019

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here are two good reasons readers should be ask- ing if our drinking water is safe. The obvious one is the responsibility we share to create healthy communities for our families and ourselves. The other reason is that some aspects of our drinking water prob- lem represent enormous undertakings, offering signifi- cant business opportunities for plumbing professionals. Lead Infrastructure Sometimes it seems as if the mainstream media is looking for ways to alarm the public and boost their audience ratings, but lead in the bloodstreams of our children remains a genuine problem. It is likely caused to a significant degree by lead service lines installed in the first half of the 1900s and perhaps lead soldering, which wasn't banned until 1986. We drink about 1 billion glasses of water per year from 152,000 public water systems. The Centers for Disease Control and Prevention says lead poisoning can damage the central nervous system, kidneys and repro- ductive system. At high levels, especially in children, it can cause coma, convulsions and death. The Natural Resources Defense Council notes that about 6 million lead service lines are in the ground across the country needing replacement. And Rachel Layne of CBS News wrote last November that reports from the American Water Works Association (AWWA) suggest, "[piping is] being replaced at an average rate of 0.5 percent a year - at that pace, it would take roughly two centuries to renew the whole system." Meanwhile, AWWA's Paul Olson believes there has been some improvement in the situation in the past 15 years, especially in the past few years since 12 or more deaths in Flint, Mich., thrust drinking water into the national media spotlight. Around the time of the Flint tragedy, a University of California study found that at least 21 million Americans were getting water from sys- tems violating EPA health standards. "Restoring the existing system will cost another $1 trillion and take about 25 years," Olson explains. "We do surveys every year showing that we certainly have not solved the problem. But despite growing cities, our new infrastructure needs have been marginally reduced, rath- er than getting worse. We're trying. Nobody likes lead." Olson describes the numerous economic, political and technical challenges faced by cities as they accept the reality of aging lead and other infrastructure. Trenchless Line Replacement One bright spot is the success of relatively new trench- less line repair and replacement technologies. Some of these have been applied to lead service line replacements in the Michigan cities of Flint and Lansing, as well as Chicago and other cities across the country. Trenchless means you don't have to dig up the whole existing line, Olson explains, which provides some relief for the difficult municipal/homeowner cost problem. It also reduces the number of homeowners resisting what could be a life-saving upgrade. There are two categories of trenchless remedies: lin- ings for existing pipe and pipe bursting or splitting. Linings can come in the form of plastic tubes, sprays or felt plus resin, which cures after it is inserted. In all these cases, the lining is pulled into an existing pipe, sealing off the water from contact with the old pipe exterior. Pipe bursting or splitting are used to completely replace a line along the path of an old pipe, again with minimal digging. The new pipe or tube is fitted with a bursting head, shaped almost like a bullet. It June also have fins to help break the old pipe as it moves through the line. The tip of the bursting head is narrow enough to fit inside the existing pipe, and then it widens to a few inches larger than the new pipe. The bursting head and the new pipe are pulled through the host pipe using a chain and winch, fragmenting the old pipe and creating a cavity for the new pipe. If neces- sary, the new pipe can be a bit larger than the pipe it is replacing. For some of the harder materials, a cutting head is needed and the pipe is split rather than fragment- ed. In many of these operations, small CCTV cameras are used to guide new tubes or liners into position. Challenges in Flint "We've done thousands of replacements in Flint," says Joe Parks from Flint-based Goyette Mechanical. "We had between four and six crews going in 2017 and 2018." Parks says one of the biggest problems was the scale of the project and scheduling the work with homeown- ers. Technical perils included avoiding existing water

The Future is Now

By BF Nagy

Is America's Drinking Water Safe?

Aging infrastructure is putting our drinking water at risk.

Flint, Mich., made national headlines as toxic amounts of lead were found in its drinking water in 2014-2015. Photo credit: iStock.com/LindaParton