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Recent events highlight need for safe water for food production


Water is an essential component of many types of food products. Processors, manufacturers, and packers use water to clean, cool and even transport foods during production (in flumes for example). Water is, of course, also used to make ice and beverages of many types.


Cantaloupe are sometimes washed before being packed for distribution to wholesalers and retailers.

Water, mixed with detergents and antimicrobial compounds, is essential to clean and sanitize equipment and the food production environment. The quality of water is especially important in the food industry, and the impact of unsafe water sources cannot be overestimated.

In the United States we tend to take the availability of safe water for granted, because we as a nation have enjoyed a bountiful supply. Our municipal water systems consistently provide safe drinking water supplies to millions of consumers and the record of accomplishment has been very good.

However, dramatic contamination events occur, so we must avoid complacency. A few examples include:

  • 1993 Milwaukee, WI, Cryptosporidium parvum parasites in the public water supply sickened 400,000 people, killing more than 100;
  • 2000 Walkerton, Ontario, E. coli O157:H7 contamination of the municipal water system sickened 5,000 people and killed five;
  • 2015 Flint, MI, it is confirmed that switching the source for the public water supply from Lake Huron to the Flint River, known to include high levels of corrosives, caused lead contamination because the river water eroded pipes and solder joints. The entire population was exposed to high levels of lead for many months before it was confirmed. The lead was at toxic levels for 12,000 or more children. The number of related deaths is unknown. Many of the children face learning disabilities and life-long health problems.
  • 2016 El Paso County, CO, more than 200 toxic industrial compounds called perfluoroalkyls (PFAs) were found in 106 samples from drinking water systems that serve 70,000 customers. These compounds, even in small quantities, are believed to be mutagenic and disrupters of the bodies’ endocrine system.

Given the real possibility that water systems may contain microbial and/or chemical contaminates, it is part and parcel of any food safety inspection to require that operators prove the potability of any source of water used in a food plant. Potable is a somewhat archaic term, from the Late Latin potabilis, meaning “drinkable.”

Inspectors often ask food facility operators to conduct annual microbial tests, even on municipal water systems. This is an important parameter and inspectors should not overlook this requirement. Inspectors may also require samples to be taken from a facility’s plumbing to ensure that cross-connections have not contaminated the facility’s distribution system.

Most utilities are able to maintain the minimum 0.2 ppm Free Active Chlorine concentration needed to ensure the microbial safety of water, however, dead-end lines may lack sufficient circulation and old pipes or loose joints may allow ground water intrusion, compromising the water system.

Typically, water plant operators rely on the coliform test to determine the success of water disinfection. While these microorganisms are not pathogenic, their presence in a water system indicates ineffective chlorination, and thus the potential for the presence of pathogens.

When found, the usual response is to conduct a second test for so-called generic E. coli bacteria. If E. coli bacteria are found, the facility may not use that water system and must provide mitigation, such as hyper-chlorination, and they must re-test such water before putting the system back into use.

The Food Safety Modernization Act of 2011 (FSMA), in its Produce Rule, has a zero-tolerance approach for generic E. coli in agricultural water, including that used on post-harvest produce. This is an appropriate test, because it is common for produce facilities to use wells for water processes such as washing and cooling, without disinfection. The coliform test would not be an appropriate test for such systems, as coliform bacteria are likely to be present in non-chlorinated systems, and in themselves cause no harm.

The regulation of agricultural water supplies is very spotty. County health departments often enforce the EPA’s Safe Drinking Water Act, but stop short at the regulation of water used in agriculture.

Consequently, regulations have not required chemical, microbial or radiological tests for such water supplies, even though they are used directly on produce for human consumption.

Currently, food safety auditors ask for microbial tests of these water supplies as part of a third-party food safety audit, but construction criteria and pre-approval of these systems, and the all important chemical tests, in most cases, are missing from the standards.

This is a gap in our food safety controls, and FSMA and its Produce Rule have not addressed this problem. The FDA is apparently leaving it up to local public health agencies to decide whether to regulate a farm or packinghouse’s water supply. Given the poor state of funding for most local public health departments, a new initiative to identify and regulate the water supplies for hundreds of thousands agricultural water systems is highly unlikely.

In this event, it is very important the third-party auditing firms, the last line of defense for food safety, revisit the standards for the safety of these systems and become more aware of potential chemical and radiological hazards, and not just the microbial aspects of water used in food production.


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