Everything You Need to Know About Water Vending Machines

Our recent analysis found that water vending machines tend to be most concentrated in the corners of San Diego County with lower incomes and college attainment and higher percentages of rental units, non-citizens and Latinos.

If you’re one of the customers that purchases water by the gallon at one of the roughly 900 vending machines around San Diego County, you might be curious to know more about how they work. Here’s our round up of frequently asked questions. 

How Are Water Vending Machines Supposed to Work?

Water vending machines take in tap water and – like a souped up water fountain – apply a variety of filters and treatment techniques aimed at improving its taste, smell and appearance.

The California Health and Safety Code lists treatment techniques the machines can use and requires that such “distillation, ion exchange, filtration, ultraviolet light, reverse osmosis, mineral addition, or any other acceptable process is done in an effective manner.”

Those techniques typically are used in combination. Primo Water Company, which operates more than 80 percent of water vending machines in the state, advertises a five-step process. (A Primo Water Corporation representative declined an initial request for an interview and did not respond to follow-up messages.)

Is Vending Machine Water Safe to Drink?

The first thing to remember is that the machines typically draw water from tap water agencies, which are themselves subject to rigorous testing standards.

In a written response to a list of questions, a spokesperson for the California Department of Public Health, which is responsible for licensing and inspecting water vending machines, said that the kiosks are “a low public health risk” and that the agency “is not aware of any confirmed illnesses linked to the consumption of water from a water vending machine or retail water facility.”

The machines are required to have an automatic shutdown feature if the disinfection process fails under California law; otherwise, vendors are supposed to check everyday that disinfection is working. The vending machines also have to meet sanitary standards and get cleaned roughly every month.

With that said, third-party researchers who have tested vending machines have found some evidence the machines may not always work as advertised. More on that below.

How Frequently Are Water Vending Machines Inspected by the California Department of Public Health?

Not very often. The state public health department appears to inspect only a fraction of machines to see if they’re following the rules. An analysis of annual summaries suggests the department inspected fewer than 1 percent of water vending machines in recent years – even though the state Health and Safety Code calls on the department to inspect at least 20 percent of the machines. The agency declined to comment on the percentage of water vending machines it inspects annually. 

(We previously reported on how lightly regulated the industry can be.)

How Frequently Does the California Department of Public Health Find Problems with Water Vending Machines, Water Stores and Bottled Water Companies?

Water vending machines were found to be in violation of the California Health and Safety Code 58 times between 2020 and 2023, almost one violation found for every two times the department inspected a machine. 

The department’s annual reports also summarize problems involving water vending machines, water stores, water haulers and bottled water companies as a group. Those reports show that the California Department of Public Health found 132 major violations of health code between 2020 and 2023 across all of those categories – one violation for every five inspections.

An agency spokesperson said that ratio was to be expected because the department prioritizes inspecting new applicants and vendors that were the subject of a complaint. 

Complaints themselves are rare. A California Department of Public Health representative said in July that the agency has only received 11 about water vending machines since September 2020.

One of the most common ways water vendors can run afoul of state law is by operating without a license or permit. And since 2020, state public health officials have found 32 violations of a health code standard requiring vendors to check for coliform bacteria at least once every six months and to submit the analysis to the state. (Coliform bacteria generally don’t make people sick but might indicate the presence of more harmful bacteria.)

What Have Tests of Vending Machine Water in California Found?

In 2020, Loma Linda University researchers Thomas D. Hile, Stephen G. Dunbar and Ryan G. Sinclair published a study testing water vending machines in the Eastern Coachella Valley. 

They found that roughly a fifth of water samples had a heterotrophic plate count, a measure of the presence of bacteria in water, that exceeded EPA regulations. Eighty-one percent  contained the kind of bacteria that can give people diarrhea, fevers and headaches. And a majority tested positive for Enterococcus faecalis, a sign of fecal waste in water.

That doesn’t necessarily mean vended water is making people sick. The microorganisms found in the water might not be concentrated enough to cause illness, Hile said. 

The results also suggest that some vending machines might not filter water effectively. The machines are meant to remove chlorine used to disinfect tap water for the sake of taste, but the researchers found 60 percent of water vending machines contained residual chlorine anyway. 

The Loma Linda team is not the first to find that water from vending machines does not consistently meet state standards. A 2002 report released by the Environmental Working Group found that a third of the 274 water vending machines researchers sampled in California exceeded state standards for trihalomethanes, a byproduct of treating water with chlorine that has been linked to an increased risk of cancer and other health effects if consumed long term. 

How Can I Check if a Water Vending Machine Is Properly Maintained? 

Here are a couple of steps you can take to see if the machine you’re about to use has been serviced recently and is clean.

• Check to see if the machine is currently licensed by the state. It should have a sticker number, which is usually the last two digits of the year it was licensed followed by a string of numbers. For example, a machine that has a current license for 2024 will have a sticker number of the format 24-XXXXX. 
• Check the date the machine was last serviced. The date of last servicing is sometimes written on a label on the machine and other times programmed into a digital display. If the machine hasn’t been serviced in the past 31 days, it’s out of compliance with the state health code. 
• See if the machine looks clean and well-maintained. One trick Sinclair recommends: Put your phone camera in selfie mode and use it as a mirror to look at the spigot itself without touching it. If you see any rust or slime, Sinclair said, you might consider using another machine. 
• Look for other consumer disclosure information. Machines should be labeled with additional information about who operates them and how they treat the water, if at all. There should also be a phone number to call for complaints and questions. 
• Find out more about where the machine gets its water. In California, the State Water Board offers these step-by-step instructions for identifying the tap water system that serves a given location. This map is another useful resource. Once you know the tap water system, you can look up its regulatory records using this search portal.

Want more tips? The Community Water Center, a Visalia-based nonprofit that advocates for safe drinking water access, published this handout with recommendations for water vending machine users.