Manmade Snow From Recycled Sewer Water May Contain Antibiotic-Resistant Bacteria

By Ashley P. Taylor | October 15, 2012 2:17 pm


This winter, an Arizona ski resort, Snowbowl, will be the first to use treated sewage water, and sewage water alone, to make manmade snow. Recycling’s usually a good thing, but opponents of the plan worry about chemicals left in the snow, and an August report by a civil and environmental engineer says that the recycled water, already used for irrigation in Flagstaff green spaces, may contain antibiotic-resistant bacteria.

As Virginia Tech’s Amy Pruden describes in an unpublished report, covered by The New York Times Green blog, her group tested reclaimed water from various green spaces irrigated by Flagstaff’s recycled water and found five of the eight antibiotic resistance genes that they were testing for. These genes allow disease-causing bacteria, such as Staphylococcus aureus, to flourish despite antibiotic treatments. It’s unclear whether the bacteria in the wastewater that contain these genes are disease-causing, but growing them in a dish to find out is the next step, Pruden told the Times. Finding antibiotic-resistant bugs in the water would shift concern to alarm, she said.

Pruden is not the first researcher to be concerned about the growth of antibiotic-resistant bacteria in effluent from wastewater treatment plants. A University of Michigan lab previously found that wastewater treatment plants were a source of antibiotic-resistant bugs. The plants foster bacterial growth to break down organic matter, then treat the effluent with ultraviolet light or chlorine to kill bacteria before discharging the wastewater, but the treatment doesn’t kill all microorganisms.

Nothing has changed in response to the findings yet, but Pruden has been appointed to an advisory panel in Flagstaff that will decide how to respond to the possibility of having antibiotic resistant bacteria in water already used for irrigation. Snowbowl plans to start spraying manmade snow around Thanksgiving.

Ski slope photo via Jennifer C./Flickr

  • Bob

    Leaving out a few actual facts:
    Although this will be the first resort to use 100% reclaimed water, many resorts have been using this to make snow for years. Mt Hotham in Australia has been using 90-95% reclaimed water for years and has received many awards for their conservation efforts.

    The real concern is that IF these reports DO prove that the wastewater has antibiotic-resistant ‘bugs’ then the city parks (which host many family picnics and events and are often very muddy due to rain plus sprinklers) have been sprayed with them for years. Where were the scare articles before snowmaking started making headlines?

  • hhb

    There is no such thing as “new” water, so whether this water goes to make snow or not if there’s bacteria surviving the treatment process it’s going to go back into the environment via some method. The water you’re drinking today probably passed through a dinosaur at some point. It is our “advances” that are changing the game.

  • Frank

    Read this quote from a June 2007 issue of Onsite Water Treatment The Journal for Decentralized Wastewater Treatment Solutions:

    “We’ve got to figure out a better way to deal with recycled water than thinking that it is really recycled,” says Frank Pecarich, a soil scientist retired from the US Department of the Interior.

    “One of the things some people say is that all water is recycled. This is true. The problem is, though, that it wasn’t going through a tertiary treatment plant, but Mother Nature’s system. The water we drink is filtered through the soil profile. “When you replace that with tertiary treatment you’re not replacing the water cycle; you’re just short-circuiting or short-cutting it and leaving out a tremendous bacteria-cleansing mechanism of the soil and the profiles of materials it must go through before it reaches the aquifer. There has been great success in getting recycled water to flow through bogs, marshes, and particularly sand to get fairly clean water, in effect letting the whole world of biology go to work for you.”

    Read the whole article here:

  • Jim Bynum

    A July 2000 study by the Corps of Engineers research on one wastewater treatment process treating secondary wastewater effluent for snowmaking shows that cell damage during this third treatment process causes the bacteria to be non-detectable. The study also shows that the bacteria can repair the cell damage very quickly and become detectable again. This is the same wastewater used to irrigate food crops and golf
    courses as well as to recharge underground water sources. Technical Report ERDC/CRREL TR-00-9

  • Lynn Reed

    I wonder where the retreated sewage water is coming from. Are they pumping it all the way up the hill from Flag? Who is paying for that?

  • ThomasD

    The report also fails to note what specific bacteria were carrying the detected antibiotic resistance genes.

    In the case of acinetobacter baumanni you have a bacteria ubiquitous in soils and ground water that is naturally resistant to most all antibiotics. While this may sound horrific the bacteria is really only a threat for the strongly immunocompromised and/or severely ill.

    Which makes it a significant problem in hospitals, but a non-issue for otherwise healthy skiers, and just about everyone else – it better be, the bug is literally everywhere.

    If organisms of no, or very limited, pathology were the source of the findings then the report is being used to generate a gross misperception of the potential risks associated with using treated effluent.

    The study further notes that detection of antibiotic resistance genes increased between the point of treatment and point of use, and they speculate this is from biofilms developing in the delivery pipes. All of which would tend to indicate that these genes are coming from organisms already present at the point of use, ones that are merely taking advantage of the new moisture source.

    While the initial study may have been performed with good intentions, it is hardly a complete picture of the situation. As used in the present article it isn’t science, this is politics masquerading as science.

    Snowbowl tried for years to gain approval to build a reservoir for natural snow melt on the mountain, and the NIMBY/antis shot them down at every turn. Now they’ve come up with an alternate source of water and this effort strikes me as more of the same.

  • Kyle

    It’s fun going from forum to forum on this issue and setting right the many misconceptions that there are. Reclaimed wastewater is not one homogenous thing. The content of the water as well as the laws that govern it’s quality and use vary state by state, country by country. The resort mentioned by “Bob” in Australia does use a percentage of wastewater, but in Australia the water goes through a much more sophisticated filtration process. The laws in AZ that govern filtration and usage are in dire need of an update. Also, antibiotic resistant bacteria is simply one of many different concerns in terms of what might be found in the water.

    Besides, that we’re “conserving” water, but using it for ski resorts and golf courses in the southwest is totally and completely ridiculous in 2012.

    Folks also claim – hey, they use this water on crops and on children’s playgrounds. Why aren’t ya’ll in an uproar over that? Well, I can tell you that an increasingly large number of people do have these concerns. And studies like the one mentioned in this article validate those concerns.

  • Musicman

    Sunlight kills most bacteria anyway. The little buggies can’t handle the UV rays. They use UV rays in hospitals to kill bacteria. That’s how bacteria in sewage run-off into our oceans is killed off, UV rays from the sun.

  • Dave

    Somehow when I think of snow, I think of compound fractures and closed injuries requiring urgent and reconstructive surgery. When I think of sunny parks and golf, I think of tendonitis, sprains and simple fractures. It’s a doctor thing. So yeah, no dirty snow, please. Or monitor it about fifty times better and longer than I think you will. And get a honest man to check downhill drainage year round. Or at least dye the snow yellow. You wouldn’t lie to us, right?

    It seems to me that pouring water contaminated with antibiotics outside just makes wild bacteria resistant even without survival of pathogens or theoretically harmless wild bacteria who received genetic resistance during an interspecies exchange before the trip outdoors.
    The idea seems to be that the wild things will metabolized residual antibiotics, without becoming resistant, or changing pathogenicity, or exchanging resistance among micro organisms. That’s not proven.


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