The Total Coliform Rule is a national primary drinking water regulation that was published in 1989 and became effective in 1990. The rule set both health goals and maximum contaminant levels for total coliform in drinking water. The rule also provided baseline requirements for testing that water systems must undertake. Coliforms are a large class of micro-organisms found in human and animal fecal matter, used to determine whether the drinking water may have other disease-causing organisms in it. A high total coliform level in water indicates a high probability of contamination by protazoa, viruses and bacteria that may be pathogenic.
On December 20, 2012, the Environmental Protection Agency signed off on final revisions to the rule to be submitted for publication in the federal register. Based on advisory committee recommendations, the revisions will require public water systems that are vulnerable to microbial contamination to identify and fix those problems. More specifically, public water systems that are vulnerable to microbial contamination in the distribution system (as indicated by monitoring results for total coliforms and E. coli) will be required to assess the problem and take corrective action that may reduce cases of illnesses and deaths due to potential fecal contamination and waterborne pathogen exposure. The revisions will also establish criteria for public water systems to implement reduced monitoring, thereby incentivizing improved water system operations.
Some states, like California, have requirements that were already stricter than the federal requirements, and compliance with this new revision to the federal Total Coliform Rule is not required until April 2016. As a result, the publication of these changes to the rule is unlikely to have any immediate impact on many public water systems, but it may encourage states to respond with their own regulatory changes to either mirror or strengthen the new federal requirements. Many utilities already rigorously test for both total coliform and E. coli; or, they test for E. coli if there is any total coliform positive result. Because utilities must strictly adhere to regulatory sampling and notification requirements to protect the public health, and to prevent liability suits, there is also unlikely to be any immediate changes in utility sampling conduct based on this revision to the federal rule — absent specific changes in the state regulations, which govern testing. But time will tell.