There is no question that the water infrastructure in the United States is aging to the point of needing major repairs. However, there is more than just money standing in the way of making the necessary upgrades to the nation's water delivery system. It's asbestos.
When the water infrastructure
was initially built, experts surmise that up to 200,000 miles of asbestos cement pipe was used when steel wasn't readily available. In the 1940s, although historically health risks were known regarding asbestos, most people were unaware and civil engineers readily embraced the use of this strong, durable and readily available composite to help supply water to burgeoning suburban areas.
Today, engineers surmise that approximately 15% of the water that currently flows throughout the U.S., with higher concentrations in the western portions of the country due to the extremely fast population growth experienced in this region, is carried by asbestos cement pipe mains. asbestos cement pipe, when installed, had an expected lifespan of between 50-80 years, and many of the existing mains are reaching their maximum useful lives. However, getting them replaced isn't as easy as it sounds.
Current regulations governing the use and replacement of asbestos cement pipes are vague, at best. In most cases, governing bodies really aren't sure what to do with the existing mains and the latest scientific data isn't providing definite answers.
Lack of guidelines
The EPA is considered the prevailing authority on how to handle potentially dangerous compounds. However, in the case of asbestos cement pipe, even the EPA isn't offering any real guidance on what to do to replace and dispose of these water mains. Instead, they are leaving the responsibility in the hands of local governments. Engineers have a responsibility to check regulations during the design phase of a project.
The issue at hand at the local level is that regulations can vary from state to state and even between regulatory agencies within a given state. California, for example, has 19 different agencies with a stake in deciding how to handle asbestos cement pipe, each with their own opinions and levels of stringency attached. States such as Montana require removal of all asbestos cement pipe and associated debris. Contractors and municipalities which are unaware or ignore regulations are faced with the possibility of huge fines and/or project delays.
One method for rehabilitating older, asbestos cement pipe is pipe bursting
. The asbestos cement pipes are broken while still underground. The cavity is widened and a new pipe is pulled into place. Some states interpret EPA regulations as a ban on pipe bursting while others interpret it to mean that contractors simply have to be licensed in proper asbestos handling before they can remove asbestos cement pipes.
The main crux behind the lack of uniform guidance simply points towards a lack of solid data regarding the impact that asbestos cement pipes will have on the environment as they are being replaced. Obviously, asbestos has been shown to have a major health and safety risk when used in other applications and until there is solid data available that shows that asbestos cement won't pose a large health or environmental impact when removed, those left with the responsibility of replacing it will continue to struggle with finding a solution.
Efforts are being made to collect data to provide insight into the potential environmental impacts of pipe bursting or other asbestos cement pipe removal/replacement methods.
Samples of soil, air and water have been collected from pipe bursting sites in order to determine the level of asbestos contamination that may exist. The results are mixed.
A current study is expected to reach completion this year and the hope of many local regulators is that the findings will produce more solid federal guidance with regard to the proper way to handle the replacement of asbestos cement pipe. It is this guidance that engineers and contractors are looking for when it comes to better understanding the risks associated with asbestos cement pipe rehabilitation and offering them a "best practice" for replacing the aging pipe.
Many municipalities in a hurry to complete rehabilitation projects are choosing other methods of pipe replacement such as; slip-lining, complete removal of asbestos cement pipe or installing new pipe and abandoning the asbestos cement pipe in place. Much of the concern from regulators is what will happen when repairs are necessary in the future. Pipe bursting asbestos cement pipe leaves friable asbestos in the ground which has the potential to be a health, safety and regulatory issue during future excavations. The asbestos cement pipe left in the ground is considered a regulated asbestos-containing material which essentially makes it a hazardous waste site (Class II or IV landfill.
Contact Bruce Kirby:
Calls welcome 406-250-6902