EPA Responsibilities and Cross-Connections

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Although EPA does not under the provisions of the NPDWR require public water system to initiate or implement a cross-connection control program plan, EPA does strongly encourage states to implement the existing cross-connection control programs pursuant to the state drinking water program. While there are cross-connection control programs in place in many locales, many others lack such programs. There is evidence that inconsistent implementation of such control programs can result in public health risk (NRC, Drinking Water Distribution Systems: Assessing and Reducing Risks, 2006).

The EPA Office of Ground Water and Drinking Water published an issues paper on August 13, 2002 entitled Potential Contamination Due to Cross-Connections and Backflow and the Associated Health Risks. The nature and purpose of the paper was to examine the public health risk associated with cross-connection. The study reviewed the occurrence, magnitude, nature, method of detecting and controlling the occurrences of a cross-connection incidence. The Executive Summary states that backflow risks can be mitigated using preventive and corrective measures. Preventive measures would include the installation of backflow prevention devices and assemblies, and control cross-connections within the distribution system and individual service areas. Corrective measures would include flushing and cleaning the distribution system after a detected incident.

The finding and conclusions are as follows:

  • Plumbing cross-connections constitute a serious public health hazard.
  • Pesticides, sewage, antifreeze, coolants and detergents were the most frequent types of contaminants reported.
  • There are numerous, well-documented cases where cross-connections have been responsible for contamination of drinking water, and have resulted in the spread of disease.
  • The problem is a dynamic one, because piping systems are continually being installed, altered, or extended.

EPA’s position statements are as follows:

  • Control of cross-connections is possible, but only through thorough knowledge and vigilance.
  • Education is essential, for even those who are experienced in piping installations fail to recognize cross-connection possibilities and dangers.
  • All municipalities with public water supply systems should have cross-connection control programs.
  • Those responsible for institutional or private water supplies should also be familiar with the dangers of cross-connections and should exercise careful surveillance of their systems.