Clearwater - Most Requested Information

If you have a question or concern that is not addressed on this page, send an e-mail to Tucson Water's Public Information / Conservation Office (PICO).

Am I receiving the Clearwater blend at my tap?
Possibly. For 8-10 years, the Clearwater blend will be very similar to the average groundwater most of our customers have been using. The blend will also mix repeatedly with groundwater from other sources as it flows from the Clearwater facility to customer taps. Because of this, there is no way to use water quality characteristics to track the Clearwater supply as it flows through the drinking water system.
The primary purpose of using a blend of recharged Colorado River water and groundwater is to allow the City to shut down wells in central Tucson that have caused groundwater declines and contributed to land subsidence. Because of this, the blend is first directed into those areas of town where these wells were located — mostly in central Tucson. Since 2001, more than 80 wells have been taken out of service or put in standby mode (shut off, but kept ready for use to meet emergencies). This has allowed groundwater levels in central Tucson to begin to recover naturally. Any of the blend that is not used up in the area where the wells have been put on standby flows or is pumped wherever it is needed to meet customer demand or to fight fires.
Since 2001, the amount of Clearwater blend has risen to approximately 50% of the water Tucson Water delivers annually. During the summer months, when average daily demand for water is around 130 MGD, the water supply from Clearwater will be used up relatively quickly, before it can spread very far across our service area. During the winter months, when average daily demand is less than 80 MGD, the blended water will spread over a much wider area. On some low use days, most of Tucson Water's customers have at least some of the Clearwater blend reach their taps.
How does the blend differ from our groundwater?
Initially, there will be very little difference between the water you've been receiving and the Clearwater blend. The Clearwater project has been designed to spread any changes in water quality over many years. In 2001, water from the Clearwater project was almost entirely groundwater. As we recharge more Colorado River water at Clearwater, the amount of recharged Colorado River water in the Clearwater blend will slowly rise until it approaches about 50%. Tucson Water distributed this 50/50 blend of recharged river water and groundwater in bottles given away at malls, public buildings, and community events.
Is the mineral content (Total Dissolved Solids / TDS) and hardness of my tap water different from the groundwater I've received in the past?
That depends on where you live. The mineral content of groundwater in Tucson varies widely, depending on the geology around each well, ranging from a low of about 160 parts per million (ppm) to a high of more than 760 ppm.
At first, the mineral content of the Clearwater blend was about 220 ppm. By 2011, the mineral content had risen to about 450 ppm. Since the Clearwater blend will be mixing with other groundwater as it flows into and through our water system, the mineral content in the water you receive is a concentration somewhere between 220 ppm and the concentration in the groundwater you've received in the past.
The level of certain minerals in water, particularly calcium, determines how hard or soft the water is. The hardness of our groundwater varies from 68 ppm to 320 ppm depending on your location. The Clearwater blend initially had a hardness of about 80 ppm and rose slowly to about 180 ppm by 2011. The hardness of your tap water likely ranges between 80 ppm and the hardness of the groundwater you've received in the past.
A note to owners of water softeners: You can calculate hardness in grains per gallon by dividing the parts per million number by 17.1 (for example, a hardness of 120 ppm/17.1 = 5.8 grains per gallon).
You can access information on mineral content and hardness, as well as view annual and monthly water quality reports, in the Water Quality section of this website.
How will the water be disinfected?
We disinfect the Clearwater blend with chlorine, just as we do with all of our groundwater supplies. The amount of chlorine in the blend is the same as we use in all of the rest of our groundwater supplies, with a target range between 0.8 and 1.2 ppm. Adding a low level of chlorine is necessary to ensure that your drinking water remains free of harmful bacteria or other microorganisms as it flows from the wells to your tap.
I have fish. Should I do anything different with the blend?
No. The Clearwater blend is disinfected with chlorine, just like all of our other groundwater supplies. Continue to practice good fish habitat maintenance by removing the chlorine prior to adding tap water to your aquarium or pond. Read our brochure about Clearwater and Your Fish for more information.
Will the Clearwater blend add fluoride to my water?
The Clearwater blend has a fluoride content similar to the average levels seen in Tucson's groundwater, about 0.4 ppm. The level of fluoride in groundwater varies based on the geology where our wells are located.
Are there substances in the blend that I should be concerned about, like TCE, pesticides or herbicides?
No. Like all of the water Tucson Water delivers, the blend meets all local, state and federal drinking water health standards. We monitor the Colorado River water that is recharged at Clearwater, the blend as it comes out of the ground and at other locations before it enters our drinking water system, and as it flows through our pipes. Access information on mineral content and hardness, as well as view annual and monthly water quality reports, in the Water Quality section of this website.
Is there arsenic in the Clearwater blend?
Arsenic occurs naturally in the groundwater in the Tucson region and is present in the Clearwater blend. At the Clearwater site, the level of arsenic in the groundwater is below the EPA drinking water health standard of 10 parts per billion (ppb). The Colorado River water that is recharged at the Clearwater facility is generally below 3 ppb. As the percentage of Colorado River water in the blend slowly rises over time, the amount of arsenic in the blend will drop toward the level seen in Colorado River water. Learn more about arsenic on the Arsenic Information page of our website.
My water comes out cloudy. Is that because of the blend?
No. Cloudy water that clears from the bottom of the glass upwards is caused by air that is dissolved in your water. It is harmless. For more information, see our Why is My Water Cloudy? page.
What is the pH of the blend?
The natural pH of the Clearwater blend is about 8.0, similar to most of the groundwater in Tucson. Tucson Water closely monitors the drinking water system for signs of corrosion and adjusts the pH of the Clearwater blend using a small amount of sodium hydroxide to ensure that the water is non-corrosive. The use of sodium hydroxide to stabilize pH levels is approved by the EPA and is standard throughout the drinking water industry.
Will the addition of the Clearwater blend affect my water pressure?
No, your water pressure will remain the same as it was prior to the delivery of the blend.