National Primary Drinking Water Regulations and Cross-Connection Control

The NPDWR established drinking water standards for the quality of water delivered to the consumer from the source to the service connection. The service connection is the piping from the public water system main to service valve or the water meter valve downstream of the water meter.

The NPDWR do not require the public water system to have a cross-connection control program in place. However, cross-connection control is mentioned in some of the rules.

The NPDWR Revised Total Coliform Rule establishes a maximum contaminant level (MCL) for E. coli and uses E. coli and total coliforms to initiate a “find and fix” approach to address fecal contamination that could enter into the distribution system. It requires public water systems to perform assessments to identify sanitary defects and subsequently take action to correct them. Examples of sanitary defects can include cross-connection and backflow issues such as backflow prevention devices not in place or not operating properly. Unprotected cross connection (e.g., hoses connected from the hydrant to the raw sewage masher spray bar in a wastewater facility is another example of a sanitary defect as is potable water plumbed directly to the raw waste system in a recreational vehicle or unauthorized connections to water mains. The rule states that a public water system on increased coliform monitoring that has a cross-connection control program approved by the State may reduce the coliform monitoring frequency

The EPA Revised Total Coliform Rule (RTCR) Assessments and Corrective Actions Guidance Manual Interim Final EPA 815-R-14-006, September 2014, Assessment and Corrective Actions, under the Revised Total Coliform Rule, states that coliform bacteria can enter the public water distribution system from customer connections and premise plumbing when a backflow event has occurred due to a change in distribution pressure. Examples of customer connections include service line connections to schools, hospitals, public and private housing and other buildings. Coliform bacteria and other contaminants or pollutants can enter the public water distribution system under certain hydraulic conditions by the way of unprotected cross-connections or protected cross-connection with failed backflow prevention devices within the building.

Proper operation and maintenance of the distribution system is the last protective barrier to microbial contamination of drinking water, which would include the implementation of a cross-connection control program by the public water system.

The NPDWR requires sanitary survey to be conducted on public water system. A sanitary survey means an onsite review of the water source, facilities, equipment, operation and maintenance of a public water system for the purpose of evaluating the adequacy of such source, facilities, equipment, operation and maintenance for producing and distributing safe drinking water, which would include an assessment of the public water system cross-connection control program.