EPA outlines plan to clean up groundwater pollution at Motorola Superfund site in Phoenix

Federal officials outlined plans to clean up half-century-old groundwater pollution under central Phoenix during a meeting with community members on Nov. 13.

Officials from the Environmental Protection Agency told community members the agency has identified its preferred plan for dealing with part of central Phoenix's groundwater pollution problem. Community members will have until Dec. 15 to comment on the plan before the EPA finalizes it.

The plan is the next step in a multi-decade process to address pollution caused by various industrial activities in east Phoenix, first identified in the 1980s. After roughly 40 years of studies and interim remedies, the plan lays out the EPA's first attempt at a permanent cleanup.

The EPA has identified 23 entities, including Honeywell, Arizona Public Service, and Motorola Inc. as potentially responsible parties for the pollution. Starting in the 1950s, companies began dumping and improperly storing a range of chemicals used in their manufacturing processes, creating an underground stream of polluted groundwater that begins near the former Motorola 52nd Street facility near Papago Park and stretches west, crossing through downtown and ending around 7th Avenue.

The area around polluted water has been designated as a Superfund site by the EPA since 1983. The agency's plan will address pollution in the westernmost of three sections within the site, where pollution is least severe. The agency does not yet have plans for the rest of the site.

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EPA would inject carbon into the contaminated areas Groundwater in the Motorola site contains five main contaminants. The most concerning is trichloroethylene, known as TCE, which is known to cause cancers, nervous system disorders and birth defects.

Pollution prevents municipalities or companies from using local groundwater, complicates construction projects with subterranean components and sends toxic vapors through soils and into some buildings. In some places, the contaminated groundwater rises as close as 20 feet beneath the land surface. None of the polluted water is currently used for drinking.

The agency plans to use 10 wells to inject liquid-activated carbon into gravel deposits that hold polluted water, creating an environment for bacteria that will treat the groundwater through biological processes. Carolyn Cooper, the EPA's remedial project manager, said the carbon itself is safe, pointing out that carbon water treatment is the same process used in many household water filters.

"The word 'injection' sounds bad, but it's been proven, and it works," Cooper said.

The agency also considered extracting groundwater, treating it above ground, and restoring it to the aquifer, though that option would be costly and complex. The EPA has already drilled extraction wells in other parts of the site as an interim remedy while it develops a long-term cleanup plan there.

The agency expects the preferred plan to cost about $14.7 million. Responsible parties are liable for cleanup costs at Superfund sites, meaning taxpayers will not pay for the work.

According to Michelle Rogow, the EPA's Arizona section manager for the Superfund program, the responsible parties will determine how they divide the cleanup costs. Honeywell and APS have already funded the feasibility study that led to the proposed plan.

"Any party that is found liable is 100% liable unless they get the other parties who are also liable to work with them," Rogow said.

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Resident wonders 'Is this safe?' Jessica Gibbs, a Phoenix resident, said at the end of the meeting she was grateful for a clear explanation of the site and issues from the EPA.

"I'm so relieved. I was looking at my water bottle as I filled it from the sink, thinking, 'Is this safe?' You've really alleviated all my concerns," Gibbs said.

Another resident, Diane Barker, pointed out how the pollution limits Phoenix's already precious water supplies.

"It's not the water we have been drinking, but we all know we live on a desert, so I'm thinking they're preparing for all the ways we can get water in the future," Barker said.

Several members of community information groups associated with the site attended the meeting. One new member, Lauren Trapp, said she had worked for several years in the late 1990s as a computer technician at the Motorola facilities associated with the Superfund site. Seven years ago, Trapp was diagnosed with Parkinson's Disease.

Recent research has suggested a link between TCE, and a rapid increase in Parkinson's diagnoses across the country. Trapp said she has no idea if her work at Motorola was connected to her diagnosis, but said she could not ignore it.

"It's a massive, growing neurological disease, and it would make sense for it to have a connection with this chemical," Trapp said.

The EPA moved to ban TCE across the country last year. State officials stopped studying instances of cancer and birth defects related to the site in 2014 because of data limitations, a move supported by community members at the time.

After gathering public comments in December, the EPA plans to issue a decision finalizing the plan by September 2025. Officials estimate the plan would take roughly nine years to complete. At that point, officials hope the water will be usable again as a water supply.

Robow said a change in presidential administration is unlikely to affect the plan, saying the Superfund process has "stood the test of time."

Phoenix residents can find information and submit comments on the plan at an EPA webpage by searching "Motorola Superfund site" or going to this link:

Austin Corona covers environmental issues for The Arizona Republic and azcentral. Send tips or questions to .

Environmental coverage on azcentral.com and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust.

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