Can Municipal Water Regulations Prevent Cross-Contamination?

On the performance assessment side, many issues surface in using rules designed to make safe water for individuals and applying them to food manufacturing facilities. For example, will the sampling regime catch contamination? Positive total coliform samples on the weekly or monthly monitoring could require repeat sampling, trigger sampling or E. coli testing, or other assessment. But positive samples would be reportable as a violation only if the system takes less than 40 tests a month or if more that 5 percent of the samples are positive. A system that has a positive sample can take more samples and stay under the threshold for public notice or violation, so that food production facilities would be unaware of the contamination, masking potential food safety risk.

In addition, where public notification is required, samples reflect water already used and the announcements (boil water advisories included) serve to protect residents prospectively. But food manufacturers who had used contaminated water may have manufactured the product and even shipped it. They would rarely have enough information to understand the risk of contamination of their facility’s piping and infrastructure. A food manufacturer could conceivably inoculate their pipes and internal water systems with difficult to trace or treat microbes and probably go about business as usual.

These rules are designed to protect household drinking water and not food manufacturers, processors, or packagers who use water provided by the most conscientious and compliant of suppliers.

Municipal Water Drawn from Deep Groundwater Wells

Many public water systems do not disinfect the water they provide to the public. As part of the research to evaluate the public health impact of this practice, the EPA chartered and funded the “WATHER” study, which took an epidemiological perspective on testing non-disinfected ground water supplies that met all the health standards. The multi-year study looked at public drinking water systems in Wisconsin. The state, like many others, does not necessarily require public drinking water systems disinfect groundwater supplies on the theory that the deep groundwater wells they draw from are safe and do not test as coliform positive.

The WATHER team announced in 2012 that they had found infective viruses in drinking water samples in 14 Wisconsin communities that did not disinfect their water, with up to 25 percent of the samples positive for infective viruses. The study, published in a peer-reviewed journal, reported that up to 22 percent of the acute gastro intestinal illness experienced in the communities was directly associated with the drinking water viruses.

Wisconsin is probably typical of the situation in other states, and while the WATHER project studied only a small fraction of U.S. groundwater systems that do not disinfect the water they distribute to customers, there is no reason to assume that a WATHER-type study would find different results in any other state.

A similar study in Minnesota found comparable results. In fact, the joint Health Department/Department of Agriculture study found 22 of 245 samples positive for Salmonella out of the 14 percent of 567 un-disinfected municipal water supplies that were tested.

But whether or not the WATHER or Minnesota data is echoed in all the other states, for the next decade at least, drinking water rules, requirements, and enforcement actions will only protect municipal water to the extent needed to achieve safe drinking water for individual households and not necessarily safe food manufacturing water.

Total Coliform Rule Complications

In February 2013, the EPA announced the final Revised Total Coliform Rule (RTCR), after a multi-year process to consider public water suppliers’ concerns. Municipalities, authorities, water districts, and private water companies campaigned for reform, claiming the following.

1. Public notice rules are not useful; in a resource-constrained environment, money would be better spent fixing issues rather than notifying the public about them. The public doesn’t really understand the data; giving them unnecessary information reduces their confidence in the public water supply and impacts their ability to get money to fix issues in the rate setting process.
2. Testing for indicators instead of targets is not conclusive. Coliforms are not necessarily pathogenic and do not always indicate fecal contamination. To the extent that a coliform-positive demonstrates a pathway, focus should be on “find and fix.”
3. Most waterborne disease comes from viruses, which are not tested for or measured. As far back as 2002, data published by the EPA highlighted the presence of viruses in chlorinated water systems, and specifically in biofilms in pipes that connected the treatment plant to the distribution system. Research showed that viruses survived in groundwater and were infective, especially embedded in biofilms in chlorinated systems, where pseudomonas biofilms are resistant to chemical disinfectants.

In response to these and other concerns from its constituencies, the EPA reformed the TCR by:

• Reducing monitoring frequency for many systems,
• Changing from coliforms to E. coli as the key indicator on the notion that it actually indicated fecal contamination,
• Changing most public notice requirements, and
• Moving away from boil water advisories except in the most onerous cases of clear and present danger in the immediate future, shifting the regulatory scheme towards corrective action.

Dubbed “Find and Fix,” the new regulatory scheme requires water suppliers to do an assessment of each significant safety problem and develop a plan to correct it. Note that a corrective action can be to study the problem further. But as long as documentation of the problem and its corrective action is provided to the state within a 30-day period, both utility and regulator need take no further action. If the problem reoccurs within a specific time frame, the rules provide for a Level 2 Assessment and other measures, but not necessarily public notice.