Contaminants are emerging as serious issues for drinking-water
providers—and Tucson Water officials don’t want their latest
findings on local contaminants to emerge just yet.

Seven years ago, trace amounts of three emerging contaminants were
found in a Tucson Water well near the Santa Cruz River in Marana. Last
year, four contaminants were identified as coming from that same well.
(See “Drink This!” Aug. 14, 2008.)

As a result, city officials decided to conduct annual testing at a
number of sites, including wells north of the sewer-treatment plants on
Roger Road and Ina Road and near the city’s recharge facilities in Avra
Valley.

This year’s emerging-contaminant testing was done a few months
ago—but Tucson Water representatives have refused to release the
results.

“We prefer not to put it out until the issue goes to the mayor and
City Council,” indicates Tucson Water spokesman Fernando Molina.

A clue to the findings, though, is contained in a September 2009
report on water quality prepared by city and county staff. “The most
recent sampling (summer 2009) detected several constituents at a
variety of wells and locations,” it says.

That would mean more than one well has now been shown to contain
measurable amounts of emerging contaminants.

The most likely candidate is a well in relatively close proximity to
the originally identified well. Serving the Marana area, these two
wells are considered “critical” to the northwest area’s water
supply.

However, the very low levels of contamination are not currently
thought to be a health hazard by authorities, including the federal
Environmental Protection Agency (EPA).

“These emerging contaminants have always been there,” emphasizes
Stephen Dean, interim water quality administrator at Tucson Water, “but
we’re just seeing them now (because of advanced detection
technology).”

Bob Arnold, a chemical and environmental engineering professor at
the UA, points out that at least some of the contaminants found in
Tucson water are common across the country.

“It’s worth watching what goes on,” he says. “… If I was living
out there (in Marana), I’d ask Tucson Water about it, but still drink
the water.”

Ben Grumbles, director of the Arizona Department of Environmental
Quality (ADEQ), proposes a four-part process to address the issue.

“We need to strengthen the science on pharmaceuticals and
personal-care products,” Grumbles says, “while improving public
understanding. Plus, we should strengthen pollution prevention and
product stewardship, and look at opportunities to revise regulations
where appropriate.”

The four substances found last year by Tucson Water were mostly
pharmaceuticals—one of several categories of so-called “emerging
contaminants.”

Other contaminants coming under scrutiny include
endocrine-disrupting compounds (EDC), which “act on the hormonal level
in organisms.” Personal-care products, trace metals and perchlorate, a
component of rocket fuel, are also emerging as items of interest.

Jon Chorover, a professor of environmental chemistry at the UA and
the co-director of the Arizona Laboratory for Emerging Contaminants,
thinks it’s important to know what is being found. However, he also
stresses that everything so far detected has been found in extremely
low dosages.

“The question is,” Chorover asks of all emerging contaminants, “are
there any biological signs (of impact)? The answer is probably yes in
some cases, and no in others.”

Contaminants which interfere with hormones, he believes, could be of
concern, pointing out that research has shown that some EDCs can
influence the sex of fish. On the other hand, Chorover thinks
pharmaceuticals and personal-care products probably shouldn’t be of
concern.

Pima County Regional Wastewater Reclamation Department (PCRWRD)
representatives don’t like to acknowledge that their two large
treatment facilities are a source of these emerging contaminants.
Tucson Water officials, though, aren’t so hesitant, concluding:
“They’re mostly effluent derived.”

In any case, Pima County is taking steps to address the issue of
emerging contaminants. First, they are spearheading the formation of a
pharmaceutical take-back program.

Even though the effort is in its infancy, if it is established, it
will be one of only a few such programs in the nation, according to
Jeff Prevatt, regulatory compliance manager for PCRWRD.

The idea, Prevatt says, is that instead of people flushing unused
prescription drugs down the toilet, officials would collect them at
drop-off spots. Those drugs would then be turned over to the federal
Drug Enforcement Agency for destruction, thus reducing pharmaceuticals
in the sewer system.

On a much larger scale, the county is also acting to directly
address EDCs. According to a study done several years ago, the Ina Road
facility—and especially the Roger Road facility—do a poor
job of handling these contaminants compared to newer, smaller treatment
plants in the area.

“The technology in ROMP (the Regional Optimization Master Plan) will
go much further in eliminating their impacts,” says PCRWRD spokeswoman
Laura Hagen Fairbanks.

PCRWRD director Mike Gritzuk says the ROMP program will allow the
Roger Road treatment plant to be replaced with one that uses a
Bardenpho-activated sludge process. The Ina Road facility, he adds,
will also be improved to totally utilize this process.

The project is estimated to cost $720 million; a $440 million ROMP
phase could be included as part of a 2010 county bond package.

However, even after implementation of the Bardenpho process, Gritzuk
assumes more will have to be done to deal with emerging contaminants
once the EPA establishes drinking-water standards for any of them.

“After Bardenpho,” Gritzuk says, “something else will have to be
added, such as membranes or disinfection. We won’t know until the
standards come out.”

This article appears in Oct 1-7, 2009.