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Water, including drinking water, waste water, and storm water; is handled by a system of pipes that deliver water to residences; commercial, institutional and industrial users; transfer waste water from users to wastewater treatment plants; and carry untreated storm water to streams and lakes. As the infrastructure of municipalities age, utilities serving the population need to replace deteriorated water pipes. Existing water pipes can be made of various components, such as clay, iron, polyvinyl chloride (PVC), concrete, and asbestos cement (A/C). These A/C pipes are potentially subject to regulation under the National Emission Standards for Hazardous Air Pollutants for Asbestos (Asbestos NESHAP) when replaced. The Asbestos NESHAP sets work practice standards designed to minimize releases of asbestos to protect human health.

When A/C pipes age, the cementitious bonds in the pipe matrix weaken, primarily due to the pH of the water, particulate in suspension, gases within the pipes, and the scrubbing effect of sandy soil caused by movement, such as tidal changes against the outside of the pipe (e.g., in coastal environments). These mechanisms degrade both the outside and the inside of the pipes, causing them to become compromised and to leak.

Once pipes begin to leak, the environment can be harmed in several ways. Leaking waste water pipes can pollute nearby waterways, such as oceans, rivers and lakes. Compromised storm water pipes can allow excess ground water, produced during high volume storm events, to seep into the pipe through cracks. Compromised drinking water pipes waste valuable finished water, which can leak out of the degraded pipes into surrounding soils. Water pipes carrying finished water have been known to rupture due to a combination of degradation and a high-pressure load, also known as a water main break.

Existing water pipes of all types run beneath and beside major roadways, run beneath buildings, and overlap other utilities (e.g., gas, electricity, cable); their replacement can potentially be problematic, especially in high density residential, industrial, and urban areas. Even replacement in suburban and rural areas can require careful navigation beneath roadways and other major structures.

In this proposed action, the EPA intends to evaluate and determine potential alternative work practice standards for A/C pipe replacement subject to the Asbestos NESHAP.