Wave of the Future

CAP water is gradually flooding back into Tucson taps.

When the history of Tucson's 1990s water wars is written, May 3, 2001 will only be a footnote. But on that day, following a six-year hiatus, Central Arizona Project water will once again start flowing. Sort of.

After the disastrous 1992 to 1994 introduction of CAP water, when hundreds of people found their pipes broken and thousands of households received a brown, stinking liquid, the system was shut down. To keep it off, over the vehement opposition of the community's elected officials and development interests, voters in 1995 adopted the Water Consumer Protection Act. An attempt to repeal it was resoundingly defeated in 1997.

Despite the act's objective of promoting CAP recharge into natural streambeds, the Tucson City Council used a loophole in the law to pour it into a series of large manmade basins in Avra Valley west of town. Arguing that this was never their intention, the original backers of the act tried to strengthen its provisions in 1999, but lost overwhelmingly.

That outcome meant the $77.5 million Avra Valley project, now known as the Clearwater Renewable Resource Facility, could be completed. In a few weeks it will become part of the Tucson Water distribution system with an annual operating cost rising from $8.5 million to almost $12 million within a few years. Of that, $4 million is to purchase CAP water, with millions more to pay for the power costs needed to pump it out of the ground.

The first step in the delivery process is for CAP water to be recharged in the Avra Valley basins, during which it will mix with groundwater. Tucson Water officials initially projected it would take only two years for this blend to become predominately CAP in character, with much higher levels of total dissolved solids. It was these tiny inorganic particles, along with a different pH level, that was commonly blamed for the first CAP fiasco.

Current Tucson Water computer models, however, predict it will be eight to 10 years before the Avra Valley water reaches a 50-50 mixture. To further dilute the amount of CAP, the water will be blended with more groundwater in the Clearwell Reservoir and then again throughout the Tucson Water distribution system. That means that unlike previously, this time almost everyone in town will receive some CAP water, even if only as a blend with groundwater.

According to Tucson Water spokesman Mitch Basefsky, the initiation of the Avra Valley project should allow 22 existing central city wells to be kept off this summer. These wells, generally between Campbell Avenue and Alvernon Way north of Broadway Boulevard, are in the area of highest groundwater depletion due to existing pumping, and thus are related to ground subsidence.

Basefsky says that at first 11 million gallons of water a day will come from Avra Valley, increasing to 18 million gallons later in the year. Next year 36 million gallons will be pumped every day, with 54 million gallons a day--50 percent of Tucson Water's total demand--in 2003 and thereafter.

Another difference with CAP water this time is the chemicals that will be added to it at the city's West Ajo Way treatment plant. As with existing wells, chlorine will be used to disinfect the blended water. Sodium hydroxide will also be put in to control the pH level.

Eventually the amount of total dissolved solids (TDS) in the water from Avra Valley will increase from the current 200 parts per million to around 450 as more and more CAP water is pumped. Because higher TDS levels can lead to quicker deterioration of water-using appliances like coolers and water heaters, a polyphosphate chemical may be added later as a corrosion inhibitor.

What won't be put in the water, however, is fluoride. After months of heated controversy during which both sides of the argument produced thousands of supporters, the City Council narrowly voted for the fluoridation of CAP water in 1992. But Basefsky says that Tucson Water has no plans to do that now because it is difficult under the current arrangements to provide consistent levels of fluoride throughout the water distribution system.

What do those who fought over the Water Consumer Protection Act think of the new facility?

Brent Cluff, a longtime advocate of recharging CAP water into natural streambeds, says, "We tried to encourage that in the Rillito and Santa Cruz rivers in order to allow the wells in the city to continue to be used. But the City Council chose not to do that. Instead they are recharging in Avra Valley where the big problem is the huge cost of pumping the water out of the ground, so you will have very costly water."

As for the quality of that water, Jerry Juliani, one of the authors of the Water Consumer Protection Act, believes, "It will improve the quality some over the original delivery of CAP water, but it's not the same as replenishing the central city wells. The CAP water is heavily chlorinated, and you shouldn't be able to taste or smell it, but you can."

Rich Wiersma summarizes the opinions of those who fought for a different outcome. "Tucson Water is betting the water will degrade in quality so slowly that people won't notice it. It's like the experiment with a frog in a beaker of water slowly being heated by a Bunsen burner. The temperature rises so slowly the frog doesn't notice until it is too late."

Former opponents of the Water Consumer Protection Act, however, praise the Avra Valley project. George Miller, who was Tucson's mayor during much of the 1990s, states, "The idea was to blend waters, and that is an excellent idea to replace groundwater. There will be a real strain on the water system with projected growth and the project is a good thing. I certainly think it is necessary."

Elaine Nathanson, executive director of the Tucson Regional Water Council, adds, "It is pretty exciting toward resolving our long-term water needs. It is a renewable resource we've been working on for 20 years, and it will allow wells in the central city to be turned off. After a lot of years, a lot of issues and a lot of political debate, the community has come together over a solution."

Eastside City Council representative Carol West, though, has some worries. While for many years she has been a strong advocate of delivering CAP water to peoples' homes, she was also involved with the earlier controversy. She now says, "I like the fact that wells in the central part of the city with the largest water declines can be turned off. But I still have apprehensions about 'will the other shoe drop'? Tucson Water staff has spent a lot of time on this, but underneath I'm concerned about it and just hope everything is as it should be."