[Pharmwaste] Finding clarity in water testing - testing for CECs in AZ

Tenace, Laurie Laurie.Tenace at dep.state.fl.us
Fri Oct 30 13:17:47 EDT 2015


One million, seven hundred sixty thousand.
Or 1,760,000.
That's the number of 8-ounce glasses of water from Flagstaff's Foxglenn Well a resident would have to drink to ingest a standard dose of Prozac from trace amounts in the well water, according to the latest testing numbers.
It's a figure Erin Young, the city's water resources manager, makes sure to emphasize when explaining the latest data from the city's efforts to test water for a multitude of trace substances that aren't currently regulated by state or federal agencies. The substances are categorized as compounds of emerging concern, or CECs, and they include things like pharmaceuticals, personal care products and endocrine disruptors.
Young presented interim results of that testing to the Flagstaff City Council last month.
The challenge for Young and the city is to interpret those results, verify their accuracy and help people understand exactly what the data mean for their health and safety.
"Since (CEC's) are not regulated, what we're missing is that conversation about...even if we find them, what do they mean?" said Brad Hill, director of the city's utilities department. "Putting these things in perspective is something we struggle with in our industry."
Crunching numbers
Flagstaff is one of only a handful of cities willing to test for compounds of emerging concern, said Hill said. The city has been doing so since 2002.
The effort to sample for these substances stems in part from a federal mandate and part from a local push to know more about the potable water coming out of taps and the reclaimed wastewater being sprayed over local parks and ski slopes.
Young's report to city council in September reviewed results of water testing completed since 2013. It showed that zero to five CECs were detected at each of seven drinking water sources across the system. The compounds that showed up include fluoxetine, or Prozac; Acesulfame-K, a calorie-free sugar substitute; and azithromycin, an antibiotic used to treat various types of infections.
The number of such compounds detected in reclaimed wastewater and effluent discharged from the city's treatment plants was approximately four to eight times higher, ranging from 23 to 47 substances detected at each test site. The sweetener sucralose; TDCPP, a flame retardant; amoxicillin, an antibacterial; and iohexol, an agent used in contrast radiography, were found in the highest concentrations.
The city also separately tested for the chemical NDMA, a potential carcinogen, which was detected in both reclaimed wastewater and treated discharge. The chemical results when ammonia lingering in wastewater reacts with chlorine used as a disinfectant. That reaction creates chloramines, which can form NDMA.
Those tests are on top of EPA-mandated testing the city completes for a list of 30 contaminants the agency is considering for future regulation.
Putting numbers in perspective
Beyond the numbers themselves, key from a public health standpoint is the amount or concentration of the substances detected in Flagstaff's water system. Prozac, which was detected at the city's Foxglenn groundwater well, was measured at 24 parts per trillion. That's the equivalent of 24 grains of salt in an Olympic-sized pool, Young wrote in her report to the city.
Azithromycin, an antibiotic, was another compound found in Flagstaff's drinking water at 37 nanograms per liter, or approximately 37 parts per trillion. A person would have to drink more than 22,864 8-ounce glasses of water to ingest an amount of the chemical that would pose a health concern, according to data provided by the Water Research Foundation, a nonprofit that invests research dollars in a wide range of water issues.
In reclaimed wastewater the concentrations of CECs were much higher.
Sucralose was the substance found in the highest concentrations in Flagstaff's reclaimed wastewater at a maximum of 58,000 parts per trillion. A person would have to drink more than 773 glasses of water per day of reclaimed water to receive a dosage above the level deemed safe.
TDCPP, the flame retardant, was found to occur in Flagstaff's reclaimed wastewater at a maximum level of 1400 nanograms per liter in reclaimed wastewater. At that concentration, someone would have to drink more than 1,148 glasses of reclaimed wastewater to ingest a dangerous amount.
At this point, no one in Flagstaff is drinking reclaimed wastewater.
In all, Young wrote in her report that the trace contaminant levels found in Flagstaff's drinking water and reclaimed water have remained much the same as in past years when the city has tested for them.
Need for review
Young also emphasized that the city's testing data hasn't yet been reviewed by the city's CEC advisory panel, a group of doctors, private, government and university researchers, city officials and health experts.
That's important because some of the results don't seem quite right. Tests that detected fluoxetine, for example, didn't detect sucralose, which commonly shows up with fluoxetine, Young said. Fluoxetine levels also were much higher than other samples collected by the Water Research Foundation. The city found 20 to 30 nanograms per liter compared with a maximum level of 0.82 nanograms per liter listed in WRF statistics.
Young said the city's testing lab compared Flagstaff's results with 558 other test results for fluoxetine, though, and found the highest level detected was 215 nanograms per liter.
"It may be that the results WRF is getting were run using a different analytical method. Or perhaps (WRF) has a mistake in units," Young wrote in a follow-up email.
Determining the accuracy of the test results and the potential human health impacts also is becoming increasingly important, and sometimes increasingly difficult, as the sensitivity of technology improves, compounds to be detected at smaller and smaller concentrations, Young said.
"It's really easy to contaminate samples at parts per trillion level," she said.
At such a small scale, there is a greater chance the devices detected false positives, or that a sample was contaminated.
"We haven't had somebody to look at data to see if it makes sense," Young said.
Evaluating health risk
It's important to remember that the compounds of emerging concern haven't been found to have health impacts at levels found in drinking water, said Alice Fulmer a senior research manager with the Denver-based Water Research Foundation. The compounds also vary seasonally and even daily, so levels found one day may not be the same as those found a few months later, she said.
"Detecting these compounds doesn't necessarily indicate any risk," Fulmer said. "Instead it's the starting point that tells us, 'Hey, let's start paying attention.'"


Laurie Tenace
Environmental Specialist
Waste Reduction Section
Florida Department of Environmental Protection
2600 Blair Stone Road, MS 4555
Tallahassee, FL 32399-2400
850.245.8759
Laurie.Tenace at dep.state.fl.us

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