Tucson is stepping up efforts to protect groundwater from PFAS contamination, launching a new treatment project and sidelining more wells as the city adjusts to new federal standards. 

Construction is underway on a new facility aimed at reducing the spread of the toxic forever chemicals in the aquifer, Tucson Water Director John Kmiec said during a city council study session on May 20.

The project is one of several underway across the region as agencies respond to evolving guidance on per- and polyfluoroalkyl substances, or PFAS.

Kmiec also reported that more city wells have been removed from regular service due to contamination concerns — part of an ongoing effort to keep affected water sources out of the supply delivered to homes and businesses. 

The Arizona Department of Environmental Quality recently announced it will be testing known PFAS contamination in Tucson: Shannon Road/El Camino Cerro and Miracle Mile/Silverbell landfill. 

We broke down Kmiec’s updates below and you can find Tucson Water service areas here. 

Background on PFAS

PFAS are man-made chemicals that degrade slowly — taking up to thousands of years to break down — and can contaminate soil and water and accumulate in wildlife. They’ve been used since the 1940s in products like non-stick cookware, clothing, and food packaging due to their chemical resilience.

Tucson, one of the largest remaining groundwater systems in the country, relies on a U.S. EPA-designated sole source aquifer with no immediate access to surface water, making PFAS contamination of the aquifer especially serious.

Kmiec noted that “water that Tucson Water serves continues to be PFAS free,” stating they continue to avoid PFAS-contaminated areas within the local aquifers.

In 2009, the City of Tucson launched the Sentry Program to proactively test and monitor groundwater, adjusting practices as PFAS health advisories evolved. Tucson Water works with state and federal agencies and has removed wells affected by PFAS contamination from service while treating groundwater. 

Regulatory developments

• On April 10, 2024, the federal Environmental Protection Agency updated its guidelines for the Maximum Contaminant Levels of six PFAS types: PFOA, PFOS, PFHxS, PFNA, HFPO-DA and “PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS.” 
• In 2025, the EPA under the Trump administration, proposed extending the compliance deadline for two types — PFOA and PFOS — from 2029 to 2031. It is also reconsidering the changed limits for the other four types. 
• Tucson has adopted more stringent limits for some PFAS types following the 2024 federal guidelines. Here’s how they compare.

*parts per trillion (ppt) (also expressed as ng/L)

Operational responses

• Kmiec said that in response to new federal regulations, Tucson Water has removed 22 wells from service “due to PFAS contamination” and put eight additional wells on an emergency use only status.
• Kmiec didn’t comment on the Silverbell West water system which, according to the meeting memorandum, continues to struggle with PFAS contamination and “continues to be provided point of use treatment devices for their fluctuating detections of PFAS compounds at or near the Tucson Water operational guidelines.”

Infrastructure projects

• Kmiec provided an update on the Randolph Park Groundwater Treatment Facility, a treatment facility established to block PFAS contamination from moving northward to other wells. He said initial drilling for the site in 2024 didn’t provide enough water for the treatment process and they are now working with the state of Arizona to find a supplemental well. 
• Kmiec confirmed that the construction of an advanced oxidation pretreatment facility at the The Tucson Airport Remediation Project (TARP) facility began in January 2025 and is expected to finish by August of 2026. This facility’s explicit use is to remove PFAS from the groundwater supply before it enters the TARP facility.
• A new funding agreement between the state and the U.S. Air Force for the Central Tucson PFAS project is under discussion after a funding lapse temporarily shut it down in early 2025. Kmiec said they anticipate the plant will return to operation soon. 
• The Northwest Wellhead Treatment Facility is under “active development” in the form of “well drilling and site preparation” following city council’s approval of the project in late 2023. Kmiec said this initiative will “return 3 Tucson water wells back into production with advanced treatment processes.” 

Coordination with federal and state agencies

• $25 million in funding from the Arizona Department of Environmental Quality is supporting the advanced oxidation pretreatment project.
• Various investigations and assessments are underway, here are the sites and the timelines:
  
  • Site: Air Force Plant 44
    Lead Agency: U.S. Air Force
    Phase: Phase 1 Remedial Investigation to “delineate the nature and extent of PFAS from two past aqueous film forming foam (AFFF) release areas”
    Status: Draft report due May 2025; final due Dec 2025
    
  • Site: Morris Air National Guard Base
    Lead Agency: Arizona Air National Guard
    Phase: Phase 1 Remedial Investigation to “define the nature and extent of PFAS releases at the base and assess risk to human health and the environment”
    Status: Draft report due May 2025; final due late 2025
    
  • Site: Tucson Airport Authority (TARP Superfund site)
    Lead Agency: EPA and Tucson Airport Authority
    Phase: Remedial Investigation and Feasibility Study to assess PFAS contamination and evaluate treatment options
    Status: Workplan due mid 2025

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New facility, more wells offline as Tucson intensifies PFAS cleanup efforts

by Carolina Cuellar, AZ Luminaria
June 23, 2025

<h1>New facility, more wells offline as Tucson intensifies PFAS cleanup efforts</h1> <p class="byline">by Carolina Cuellar, AZ Luminaria <br />June 23, 2025</p> <p>Tucson is stepping up efforts to protect groundwater from PFAS contamination, launching a new treatment project and sidelining more wells as the city adjusts to new federal standards.&nbsp;</p> <p>Construction is underway on a new facility aimed at reducing the spread of the toxic forever chemicals in the aquifer, Tucson Water Director John Kmiec said during a city council study session on May 20.</p> <p>The project is one of several underway across the region as agencies respond to evolving guidance on per- and polyfluoroalkyl substances, or PFAS.</p> <p>Kmiec also reported that more city wells have been removed from regular service due to contamination concerns — part of an ongoing effort to keep affected water sources out of the supply delivered to homes and businesses.&nbsp;</p> <p>The Arizona Department of Environmental Quality <a href="https://www.azpm.org/p/earthday/2025/6/5/225072-adeq-to-expand-pfas-testing-and-monitoring-with-new-5-million-investment/">recently announced</a> it will be testing known PFAS contamination in Tucson: Shannon Road/El Camino Cerro and Miracle Mile/Silverbell landfill.&nbsp;</p> <p>We broke down Kmiec’s updates below and you can find Tucson Water service areas <a href="https://gisdata.tucsonaz.gov/datasets/cotgis::tucson-water-obligated-service-area/explore?location=32.169661%2C-110.853720%2C8.89">here</a>. </p> <p><strong>Background on PFAS</strong></p> <p>PFAS are man-made chemicals that degrade slowly — <a href="https://publichealth.jhu.edu/2024/what-to-know-about-pfas">taking up to thousands of years to break down</a> — and can contaminate soil and water and accumulate in wildlife. They’ve been used since the 1940s in products like non-stick cookware, clothing, and food packaging due to their chemical resilience.</p> <p>Tucson, one of the largest remaining groundwater systems in the country, relies on a U.S. EPA-designated sole source aquifer with no immediate access to surface water, making PFAS contamination of the aquifer especially serious.</p> <p>Kmiec noted that “water that Tucson Water serves continues to be PFAS free,” stating they continue to avoid PFAS-contaminated areas within the local aquifers.</p> <p>In 2009, the City of Tucson launched the Sentry Program to proactively test and monitor groundwater, adjusting practices as PFAS health advisories evolved. Tucson Water works with state and federal agencies and has removed wells affected by PFAS contamination from service while treating groundwater.&nbsp;</p> <p><strong>Regulatory developments</strong></p> <ul class="wp-block-list"> <li>On April 10, 2024, the federal Environmental Protection Agency updated its guidelines for the Maximum Contaminant Levels of six PFAS types: PFOA, PFOS, PFHxS, PFNA, HFPO-DA and “PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS.”&nbsp;</li> <li>In 2025, the EPA under the Trump administration, proposed extending the compliance deadline for two types — PFOA and PFOS — from 2029 to 2031. It is also reconsidering the changed limits for the other four types.&nbsp;</li> <li>Tucson has adopted more stringent limits for some PFAS types following the 2024 federal guidelines. Here’s how they compare.</li> </ul> <p>*parts per trillion (ppt) (also expressed as ng/L)</p> <figure class="wp-block-table"> <table class="has-fixed-layout"> <tbody> <tr> <td><strong>Compound</strong></td> <td><strong>EPA Final MCL&nbsp;</strong>in parts per trillion (ppt) (also expressed as ng/L)</td> <td><strong>Tucson Water Final MCL</strong>&nbsp;in parts per trillion (ppt) (also expressed as ng/L)</td> </tr> <tr> <td>PFOA</td> <td>4 ppt</td> <td>&lt; 2 ppt&nbsp;&nbsp;</td> </tr> <tr> <td>PFOS</td> <td>4 ppt&nbsp;&nbsp;</td> <td>&lt; 2 ppt&nbsp;&nbsp;</td> </tr> <tr> <td>PFHxS</td> <td>10 ppt&nbsp;&nbsp;</td> <td>9 ppt&nbsp;&nbsp;</td> </tr> <tr> <td>PFNA</td> <td>10 ppt&nbsp;&nbsp;</td> <td>10 ppt&nbsp;&nbsp;</td> </tr> <tr> <td>HFPO-DA (GenX)</td> <td>10 ppt&nbsp;&nbsp;</td> <td>10 ppt&nbsp;&nbsp;</td> </tr> <tr> <td>Mixtures containing two or more of PFHxS, PFNA, HFPO-DA and PFBS</td> <td>1 (unitless) Hazard Index</td> <td>1 (unitless) Hazard Index, specifically:420 ppt for PFBS200,000 ppt for PFHxA</td> </tr> </tbody> </table> </figure> <p><strong>Operational responses</strong></p> <ul class="wp-block-list"> <li>Kmiec said that in response to new federal regulations, Tucson Water has removed 22 wells from service “due to PFAS contamination” and put eight additional wells on an emergency use only status.</li> <li>Kmiec didn’t comment on the Silverbell West water system which, <a href="https://tucsonaz.hylandcloud.com/221agendaonline/Documents/ViewDocument/MAYOR%20AND%20COUNCIL%20MEMORANDUM%20SS_MAY20-25-91.pdf?meetingId=1854&amp;documentType=Agenda&amp;itemId=75467&amp;publishId=172389&amp;isSection=false">according to the meeting memorandum</a>, continues to struggle with PFAS contamination and “continues to be provided point of use treatment devices for their fluctuating detections of PFAS compounds at or near the Tucson Water operational guidelines.”</li> </ul> <p><strong>Infrastructure projects</strong></p> <ul class="wp-block-list"> <li>Kmiec provided an update on <a href="https://www.tucsonaz.gov/Departments/Water/Dollars-at-Work/Randolph-Facility">the Randolph Park Groundwater Treatment Facility</a>, a treatment facility established to block PFAS contamination from moving northward to other wells. He said initial drilling for the site in 2024 didn’t provide enough water for the treatment process and they are now working with the state of Arizona to find a supplemental well.&nbsp;</li> <li>Kmiec confirmed that the construction of an advanced oxidation pretreatment facility at the <a href="https://www.tucsonaz.gov/Departments/Water/Water-Quality/TARP">The Tucson Airport Remediation Project (TARP) facility</a> began in January 2025 and is expected to finish by August of 2026. This facility’s explicit use is to remove PFAS from the groundwater supply before it enters the TARP facility.</li> <li>A new funding agreement between the state and the U.S. Air Force for <a href="https://static.azdeq.gov/wqarf/220101_ctpp_fs.pdf">the Central Tucson PFAS project</a> is under discussion after a funding lapse temporarily shut it down in early 2025. Kmiec said they anticipate the plant will return to operation soon.&nbsp;</li> <li><a href="https://www.tucsonaz.gov/Departments/Water/Dollars-at-Work/Northwest-Facility">The Northwest Wellhead Treatment Facility</a> is under “active development” in the form of “well drilling and site preparation” following city council’s approval of the project in late 2023. Kmiec said this initiative will “return 3 Tucson water wells back into production with advanced treatment processes.”&nbsp;</li> </ul> <p><strong>Coordination with federal and state agencies</strong></p> <ul class="wp-block-list"> <li>$25 million in funding from the Arizona Department of Environmental Quality is supporting the advanced oxidation pretreatment project.</li> <li>Various investigations and assessments are underway, here are the sites and the timelines:<br /> <ul class="wp-block-list"> <li><strong>Site</strong>: Air Force Plant 44<br /><strong>Lead Agency</strong>: U.S. Air Force<br /><strong>Phase</strong>: Phase 1 Remedial Investigation to “delineate the nature and extent of PFAS from two past aqueous film forming foam (AFFF) release areas”<br /><strong>Status:</strong> Draft report due May 2025; final due Dec 2025</li> <li><strong>Site:</strong> Morris Air National Guard Base<br /><strong>Lead Agency:</strong> Arizona Air National Guard<br /><strong>Phase</strong>: Phase 1 Remedial Investigation to “define the nature and extent of PFAS releases at the base and assess risk to human health and the environment”<br /><strong>Status</strong>: Draft report due May 2025; final due late 2025</li> <li><strong>Site</strong>: Tucson Airport Authority (TARP Superfund site)<br /><strong>Lead Agency</strong>: EPA and Tucson Airport Authority<br /><strong>Phase</strong>: Remedial Investigation and Feasibility Study to assess PFAS contamination and evaluate treatment options<br /><strong>Status:</strong> Workplan due mid 2025</li> </ul> </li> </ul> <p>This &lt;a target=&quot;_blank&quot; href=&quot;https://azluminaria.org/2025/06/23/new-facility-more-wells-offline-as-tucson-intensifies-pfas-cleanup-efforts/&quot;&gt;article&lt;/a&gt; first appeared on &lt;a target=&quot;_blank&quot; href=&quot;https://azluminaria.org&quot;&gt;AZ Luminaria&lt;/a&gt; and is republished here under a &lt;a target=&quot;_blank&quot; href=&quot;https://creativecommons.org/licenses/by-nd/4.0/&quot;&gt;Creative Commons Attribution-NoDerivatives 4.0 International License&lt;/a&gt;.&lt;img src=&quot;https://i0.wp.com/azluminaria.org/wp-content/uploads/2021/12/cropped-L-square-Primary.jpg?resize=150%2C150&amp;amp;ssl=1&quot; style=&quot;width:1em;height:1em;margin-left:10px;&quot;&gt;&lt;img id=&quot;republication-tracker-tool-source&quot; src=&quot;https://azluminaria.org/?republication-pixel=true&amp;post=36816&amp;amp;ga4=291628854&quot; style=&quot;width:1px;height:1px;&quot;&gt;&lt;script&gt; PARSELY = { autotrack: false, onload: function() { PARSELY.beacon.trackPageView({ url: &quot;https://azluminaria.org/2025/06/23/new-facility-more-wells-offline-as-tucson-intensifies-pfas-cleanup-efforts/&quot;, urlref: window.location.href }); } } &lt;/script&gt; &lt;script id=&quot;parsely-cfg&quot; src=&quot;//cdn.parsely.com/keys/azluminaria.org/p.js&quot;&gt;&lt;/script&gt;</p> Copy to Clipboard

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