Update: March 2018

Marana Water, in its efforts to continuously provide high quality service and product to its customers, recently began a voluntary water quality sampling program to gain more information about our water system.  Based on information recently received from other water providers in the region, Marana Water conducted water quality testing for unregulated compounds called perfluoroalkyl substances (PFAs). Two of these compounds, PFOA and PFOS, have health advisories from the United States Environmental Protection Agency (USEPA). Recent testing by Marana Water has shown that some of our drinking water wells have these compounds present. 

What is PFOA and PFOS? How is it used?

PFOA and PFOS are chemicals that were widely used in commercial products. They have a strong ability to repel other compounds so they were commonly used as stain protection on fabrics and clothing, non-stick cookware, furniture protection, paper packaging protection, as well as in firefighting foams. Most of the companies that use these compounds have phased out their use over the last ten years. However, because the compounds are highly stable and resistant to breakdown, they are commonly found in the environment. 

What is an unregulated compound?

An unregulated compound means that the compound is not part of the mandatory water quality testing that the department is required to do per state and federal rules. The USEPA is currently examining PFOA and PFOS as potential drinking water contaminants, but has not created a maximum contaminant level regulation at this time. These compounds have been found across the nation and have the ability to remain in the environment for a long time.  While PFOA and PFOS are being actively studied by the USEPA, they have issued a lifetime health advisory for drinking water systems to use as a benchmark. The current lifetime health advisory value was set in 2016 for both compounds is 70 parts per trillion, or nanograms per liter. Based on sampling events in December 2016 and December 2017, some of the Marana Water wells tested show concentrations that are above this lifetime health advisory level. To give an idea on what a part per trillion means, it is like one second in 32,000 years or one square inch within 250 square miles.


The information below will help identify the testing results for specific neighborhoods. The chart on the left, reflects sampling data gathered from events in December 2016 and 2017. The colors correspond with the water systems in the map on the right. If you click on the image, it will enlarge for better viewing of the results.


Is the quality of my water OK?

All Marana Water systems meet the current required federal and state water quality standards for drinking water. However, as your local water professionals, we also know that not every chemical compound or microbiological risk is regulated. By staying aware of our local environment and the environment of our nation, we can conduct additional, voluntary water quality sampling to help us understand and identify potential issues before they become a drinking water regulated item. Activities like this sampling program will allow us to effectively plan for possible additional infrastructure and treatment options in a proactive, not reactive, manner.

can i treat my water at home?

With respect to PFOA and PFOS, there are two types of treatment that have shown to be effective in reducing or eliminating these compounds from the water. These treatments are activated carbon and reverse osmosis. Activated carbon filters are relatively common and can be found at most grocery stores and home improvement stores. Examples of these devices are filtering water pitchers and in-line refrigerator filters. Use of these devices has shown a positive effect in reducing or eliminating PFOA and PFOS compounds, as well as others. Here is a link to a study using University of Arizona research showing the effectiveness of a few of these devices. 

how can PFOA and PFOS in the water affect my health?

The USEPA is continually testing and researching the likelihood that these compounds can be harmful in drinking water. While the research continues, the USEPA has established a lifetime health advisory of 70 parts per trillion for both compounds. This advisory was established to provide a level of protection for all Americans throughout their lifetime from any adverse health effects resulting from exposure to PFOA and PFOS in drinking water. The health advisory is designed to protect the most sensitive populations: fetuses during pregnancy and breastfeeding infants. If you live in a water system that has shown PFOA and PFOS levels greater than the health advisory, you may want to take steps to limit or avoid consumption of water directly from the tap. While the department works on the next steps to address this issue, you may be able to treat water at home to reduce the levels of these compounds. 

What are the next steps?

Marana Water will be scheduling additional sampling of our wells and delivery systems over the course of the year.  Having information on what is present in our environment with more data will allow us to determine why this compound is present in our region and what steps we may want to explore to mitigate any occurrence of this in the future. Some of these future steps may include building additional infrastructure to blend water from other sources or using advanced treatment processes at the water source. This research is ongoing. We plan to work with the other water and wastewater utilities in the area to combine as much of our research data to develop a complete picture. As the department gathers additional information, we will provide updates to the community through the Marana Water website,