Although experts are unsure yet if it poses a health risk, sophisticated new techniques have detected pharmaceuticals such as antibiotics, anti-inflammatory drugs, X-ray contrasting agents and antiepeleptic medication in the effluent flowing in the Santa Cruz River channel in Northwest Tucson and Marana and in nearby wells used to monitor ground water quality.
In a separate study, trace amounts of estrogen regulators, hormones and synthetic hormones that affect the endocrine system and which in large quantities could potentially cause birth defects, were also detected in the effluent and in ground water.
Officials from Tucson Water, which controls most of the average 49 million gallons of effluent pumped into the river channel each day, said no pharmaceuticals have been detected in wells that provide potable water to customers.
"It's definitely a concern, but no one is sure yet if this is a serious problem," said Marie Light, a project manager with Tucson's water utility. "We're dealing with new techniques and very new information. It's all very cutting-edge and we're very far out of the envelope in trying to get more information."
Officials in other jurisdictions, including Marana, which is negotiating with Tucson to obtain a portion of the effluent, claim Tucson administrators have commissioned studies and are being less than forthright about the problem.
"There does seem to be a serious problem with the dissemination of information from Tucson Water on this issue," said Marana Town Manager Mike Hein.
Establishing whether there is a problem at all will be the first hurdle area water administrators will have to face.
Millions of gallons of the effluent flowing in the channel northwest of Tucson from Pima County's two primary waste water treatment plants at Roger Road and Ina Road percolate through the ground each day.
The effluent, which has been treated at the plants to remove solid material and kill bacteria, is a major source of recharge for the underground aquifer that is the primary source for the area's drinking water.
Some of the pharmaceuticals and other chemicals are being detected with new techniques that are able to identify trace amounts in parts per billion, whereas in the past, the chemicals were discovered only if they were within a ratio of parts per million.
A federal study noted that while individual chemicals are being found at the extremely low levels of parts per billion, the presence of a wide range of chemicals in some streams, when tallied together, were on a level that past studies have shown to have harmful effects on fish and other aquatic life.
The study did not posit any conclusions on the effects of the pharmaceuticals on humans, but urged further study of the findings.
The chemicals, which also included trace amounts of caffeine from coffee drinkers and nicotine from cigarette smokers, are being excreted primarily from human beings and are not being removed during the treatment process the effluent undergoes before being released into the channel and the aquifer, Light said.
A study by the U.S. Geological Survey of 139 streams nationwide, which included water samples taken from the Santa Cruz at Cortaro Road in Marana, found the presence of at least some pharmaceuticals in 80 percent of the streams sampled.
In Marana, pharmaceuticals detected in the federal study from samples taken in 2000 included the antibiotics Erythromycin, Trimethroprim, Tylosin, Tetracycline, and Ciprofloxacin. In all, the study detected trace amounts of 21 pharmaceuticals, mostly antibiotics in the Santa Cruz channel at Cortaro Road.
The study said the increased human exposure to antibiotics could potentially contribute to the continued development of antibiotic-resistant strains of bacteria.
Information gathered by Tucson Water, including a report by researchers from the University of Arizona's department of Chem-ical and Environmental Engineering that was presented at a symposium in Tucson in June, noted the presence of "endocrine disrupting" pharmaceuticals in test sites near the Roger Road Waste Water Treatment Facility near Interstate 10 and Roger Road.
The report indicated that while percolation through the 120 feet of sediment during recharge reduced the presence of the hormone regulators by 30 fold, "the measurements in wastewater-influenced ground water still indicated that estrogonic activity was present."
Another study compared recharge sites at the Tucson Sweetwater Underground Storage and Recharge Facility near the Roger Road plant, and the Northwest Water Reclamation Plant in Mesa. Both sites contained a variety of pharmaceuticals in their effluent and test wells.
At the northwest Tucson site, the study detected in the effluent traces of the lipid regulator Gemfibrozil; the antiepeleptic drug Primidone; and analgesics and antiinflamitories such as Ibuprofen, Keptoprophen, Naproxen and Propyphenazone.
Naproxen and Propyphenazone, along with the antiepeleptic drugs Carbamazaepine and Primidone, were also found in test wells to have infiltrated into ground water.
The city of Tucson has not publicized the presence of the pharmaceuticals in the effluent, and did not release the local studies to other jurisdictions such as the Metropolitan Water Improvement District and the Marana water utility until last week.
The Northwest EXPLORER obtained copies of the local studies through a public records request filed with Tucson Water.
Light said Tucson Water has been aware of the presence of the contaminates for more than a year.
"We became aware of this in the late 1990s and initiated a sampling program through the University of Arizona to look at endocrine interrupters and other pharmaceutical compounds," Light said.
The study was prompted by results from a study done in Germany in the early 1990s that used the sensitive detection methods to monitor pharmaceuticals in waste water, Light said.
Metro Water and Oro Valley recently concluded deals with Tucson Water to obtain shares of the effluent that the jurisdictions plans to recharge for valuable water credits from the state or use to water golf courses and turf areas.
Metro Water Director Mark Stratton said he had only heard about the presence of pharmaceuticals in local effluent "through the grapevine," but has not reviewed the studies yet.
"This stuff is all new and wide open for interpretation. Even the (U.S. En-vironmental Protec-tion Agency) has yet to begin looking at the problem or what the potential impacts are," Stratton said Friday. "We met with Tucson Water today and we did agree that all the jurisdictions would begin sharing information about this as much as we can."
Marana is in the process of negotiating for a share of the effluent, but has yet to conclude the deal, said Hein.
"We are continuing to pursue the negotiations, but we are being guarded. There could potentially be some liability issues involved with the effluent and we are proceeding with a certain degree of caution," Hein said.
Tucson is moving forward on plans for a managed recharge project in the Santa Cruz that would return even more effluent into the aquifer. The project, being developed by Tucson Water, would concentrate effluent in the channel north of Ina Road, and which if implemented, may stretch as far as the Pinal County line north of Marana.
Five different entities were embroiled in a fight over the managed recharge project for more than 20 years.
A lawsuit filed against Tucson to stop the project filed by Pima County, Marana and other jurisdictions was dropped in February 2000, after Tucson agreed to begin negotiating to turn over portions of the effluent it controlled to Marana, Metro, Pima County and Oro Valley.
Brad DeSpain, Marana's water director, said Tucson has been "less than forthcoming" about the local studies that detected the pharmaceuticals.
"We weren't informed by Tucson Water of any of this," DeSpain said. "We only heard about the U.S. Geological Survey study from an article in the Arizona Republic (newspaper) that dealt with the broad, nationwide issue, but that mentioned Cortaro Road."
In a March 19 memo to the Marana mayor and council, DeSpain elaborated his concern.
"In ongoing discussions about management of effluent supplies between Marana staff and representatives of Tucson, Pima County and other jurisdictions in the region, no disclosure of this potentially important water quality information has been offered. This lack of information sharing is of serious concern to us because it is Marana-area aquifers that are potentially impacted with possible effects on Marana residents and businesses. These effects could increase over time.
"It is important to stress that no known health risks have been established for any of these compounds at the levels that may be present in the effluent. It is equally important to stress, however, that because scientific studies have not been done, it also cannot be stated with certainty that the compounds are safe at the levels currently found," DeSpain wrote.
Light disagrees with claims that Tucson Water is not sharing information on the studies.
"Much of this stuff is on the Internet. That's where we got our information on the U.S. Geological Survey report," Light said. "The symposium information was printed last summer and anyone can get access to that. It's not like anything is being withheld."
Carol West, a Tucson council member widely regarded as being the most knowledgeable elected official in Tucson on water matters, said the issue of pharmaceuticals in the channel has not been presented to the city's mayor and council for discussion by administrators.
West said she heard of the issue from reading national studies and speaking to people she knows who are involved in hydrology.
"I'm sure that if there is a problem, we will develop a plan to deal with it," West said. "I don't think that it should be a case of anyone pointing fingers. We all use drugs, and we're all contributing to the problem."
Benny Young, a Tucson assistant city manager charged with overseeing environmental and water matters for the city, said the Tucson mayor and council would be receiving information on the studies soon.
"I've asked (Tucson Water) to put together a report that will come to the city manager and that will be forwarded to the mayor and council with regard to the possible implications both for our domestic potable water system and our secondary effluent system. At this point, it doesn't appear to me to be something that is cause for alarm, but it is something we will be tracking," Young said. "The Tucson citizens don't need to be worried about this, we don't believe."