Pipebursting AC Pipe Problematic, Says EPA

There was a time when the word “asbestos” was not primarily associated with serious health hazards.

Asbestos is a mineral fiber that has been widely used in a variety of building construction materials for insulation and as a fire retardant. Strength of its fibers and heat resistant properties ideally suited asbestos as a component for roofing shingles, ceiling and floor tiles, paper products, auto brake linings, asbestos cement and many other products, including utility pipes. Components of asbestos cement (AC) pipe are Portland cement, water, silica or silica containing materials and asbestos fibers.

AC pipe was widely used for potable water, sanitary sewer and storm drain pipelines from the 1940s through the 1960s.

“The asbestos fibers in lieu of reinforcing steel provided adequate strength with lower weight,” said Kent Von Aspern, senior project manager, HDR Inc., an architectural, engineering and consulting firm that helps clients manage complex projects. Von Aspern has been involved in the trenchless technology industry for more than 20 years and has advised the U.S. Environmental Protection Agency (EPA) regarding the use of pipe bursting and pipe reaming as they relate to AC pipe.

Von Aspern said that in addition to light unit weight, AC pipe was marketed as having very good resistance to the effects of hydrogen sulfide corrosion and soils that were aggressive to steel pipes, and having low operating costs because the smooth walls of the pipe provided low friction factors.

But as health issues relating to asbestos were documented, federal regulations significantly restricted inclusion of asbestos in most products and the manufacture of AC pipe in the U.S. ended more than 30 years ago.

Still in abundance
However, much AC pipe remains in the ground today in active water and sewer systems. Von Aspern cites a 2004 study by the American Water Works Association (AWWA) which estimated 15 to 18 percent of the water distribution and transmission systems in the U.S. are comprised of AC pipe.

And much of that AC pipe, he said, needs to be replaced.

In a presentation at the 2008 UCT conference, Von Aspern said that 630,000 miles of AC pipe in water and sanitary sewer and storm drainage systems are near the end of their useful lives.

Facing the prospect of replacing hundreds of thousands of feet of old AC pipe, project owners and contractors are faced with what they must do to comply with environmental regulations to properly dispose of old AC pipe removed from the ground, pieces of broken pipe removed in slurry during pipe reaming operations, and whether it is permissible to leave broken AC pipe segments in the ground after pipebursting procedures.

The U.S. Environmental Protection Agency (EPA) is responsible for protecting the public from asbestos hazards, and Von Aspern believes confusion over how EPA regulations apply to AC pipe continues to cause problems for utility providers and contractors who serve them.

“One area of confusion,” said Von Aspern, “is whether public agencies are required to replace AC pipe. Studies have indicated that in normal use, AC pipe does not pose a threat to public health. However, if AC pipe is tapped, cut, crushed and removed from the ground for disposal, National Emissions Standards for Hazardous Air Pollutants (NESHAP) regulations apply.”

Another point of confusion is whether contractors need special licensing to work with AC pipe.

“Contrary to common belief,” Von Aspern said, “in most cases special licensed contractors are not required to work with AC pipe (New Jersey is one exception). Many states have developed programs to train individual employees in safe practices involving the regulated AC pipe practices. These training programs provide employer exemptions for hiring licensed contractors. In addition, guidelines have been established for licensing of course providers to extend available training resources while maintaining consistency in content and message.”

Early ruling
In 1991, the EPA took the position that “crushing” AC pipe with mechanical equipment would cause the crushed material to become regulated asbestos containing material and that pipe crushed and left in place would cause the location to be considered an active waste disposal site. Without using the term pipebursting, this appears pipebursting and pipe reaming cause remnants of AC pipe to be in the category of regulated waste.

“Because pipebursting was not specifically identified in the EPA letter, interpretation of EPA’s intent has been inconsistent in the industry. Some entities are issuing clarifying documents,” said Von Aspern.

For example, in California, the Bay Area Air Quality Management District issued a Compliance Advisory addressing the pipebursting and pipe reaming construction methods, as well as EPA’s interpretation of NESHAP requirements concerning these specific techniques.

Von Aspern said the advisory clearly states pipebursting and pipe reaming have been determined by EPA to make AC pipe friable [easily broken] and that pipe pieces contain regulated asbestos material. Further, the advisory states that because the pipe reaming process does not completely remove the pipe and the bursting process leaves all the material in place, both methods of construction have been determined by the EPA to create an active asbestos waste disposal site.

Where is the industry today regarding regulations for removal of AC pipe?

Von Aspern said that key EPA staff members have surveyed the industry to learn about pipebursting, pipe reaming and AC pipe in order to gain an in depth understanding of the rehabilitation techniques. This is supposed to determine the extent to which pipebursting or pipe reaming of AC pipes constitute a threat to public health. They are evaluating existing restrictions to determine whether modifications or clarifications of the applications of NESHAP requirements are needed.

“Currently,” he said, “the EPA has expressed a preference for pipe reaming over pipebursting because reaming can remove a portion of the asbestos pipe fragments through the downstream receiving pit.

“The goal is to modify the AC pipe regulations to specifically address the public health impact of replacement by pipebursting or pipe reaming. In the meantime, the EPA and local air quality boards are aggressively enforcing current restrictions.”

Industry aid
There are a number of things that members of the industry can do to help, Von Aspen believes.

“First of all,” he said, “be aware of the regulations in your specific area regarding pipebursting and pipe reaming of AC pipe and follow the regulations.

“Second, investigations are needed to determine the state of broken pipe fragments after pipebursting, and to quantify the percentage of AC pipe recovered during pipe reaming.

“Third, support research into development of consolidating lubricants that may be used to form a conglomerated material encapsulating the pipe fragments and reducing potential health risks.

“And fourth, contact the entity responsible for regulating asbestos in your area and express your concerns regarding the impacts that restrictions on pipebursting and pipe reaming of AC pipe will have on your ability to provide safe, reliable and cost efficient water and wastewater services.”

Kent Von Aspern, HDR Inc., (925) 974 2516, Kent.aspern@hdrinc.com

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