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Superfund Cleanup

North Indian Bend Wash Superfund Cleanup

In 1981, groundwater contaminated from industrial chemicals, primarily trichloroethylene (TCE), was discovered in the southern part of Scottsdale. Investigation revealed that the contamination was the result of past improper chemical disposal by several industrial companies in the area.

The U.S. Environmental Protection Agency (EPA) declared the contaminated aquifer a Superfund Site, namely the North Indian Bend Wash Superfund Site. The area affected is from Chaparral Road to the north, Pima Road to the east, Scottsdale Road to the west, and McKellips Road to the south. View maplinks to external site  (PDF)

In some locations, the groundwater contamination has extended beyond these boundaries and those locations are considered part of the Superfund site.

Once the presence of industrial chemicals was discovered, Scottsdale stopped using these wells for drinking water purposes.

The EPA identified the parties potentially responsible for causing the contamination and determined that a long-term cleanup effort would be required. The parties potentially responsible for the contamination include – Motorola Solutions (formerly Motorola, Inc.), GlaxoSmithKline (formerly SmithKline Beecham) and SMI Holding LLC (formerly Siemens) – are responsible for all costs associated with the cleanup. The State of Arizona’s Department of Environmental Quality (ADEQ) and Department of Water Resources (ADWR) are overseeing the cleanup for the state.

Clean-up Remedy

To clean up the site and the drinking water, the potentially responsible parties built the Central Groundwater Treatment Facility (CGTF), located near Pima and Thomas roads. This treatment plant treats water pumped from four groundwater wells that contain TCE.

The CGTF is owned and operated by the city of Scottsdale. Scottsdale ensures that the water produced by the plant meets or surpasses all federal and state standards for safe and healthy drinking water, with oversight from the EPA in cooperation with ADEQ. The facility removes TCE from the water to a level that is considered non-detect (less than 0.5 parts per billion), and is far below the EPA standard of 5 parts per billion.

In 2012, EPA approved the final design for a new treatment facility for the long-term remedy for the NIBW site. This facility extracts water from well PCX-1 and uses a liquid Granular Activated Carbon (GAC) treatment process to clean and treat the water. Construction of the NIBW GAC Treatment Facility (NGTF) for well PCX-1 began in late 2012 and was completed and tested in June 2013. Previously, water from PCX-1 was treated at the Miller Road Treatment Facility.

Treated water from the NGTF is pumped to Scottsdale Water’s Chaparral Water Treatment Plant, located at Thomas and Hayden roads, where it is combined with other water in our system and then pumped into our distribution system.

The pipeline enhanced Scottsdale’s water portfolio, adding approximately 3 million gallons per day drinking water capacity. When the Chaparral Plant cannot take the water, the treated water is discharged into the nearby Arizona Canal.

Cleanup Timeline

It’s estimated that the cleanup will take approximately 30-50 years. However, large portions of the groundwater plume cleanup should be completed before that time. In March 2013, the EPA announced that the upper aquifer plume has decreased in size by 84 percent, and the total mass of contaminants in the upper aquifer groundwater has decreased by over 97 percent. Because the upper aquifer is almost restored, 25 NIBW upper aquifer monitoring wells were closed in 2013.

Clean-up will continue in the middle and lower aquifer until they reach the same level of clean-up. This is still estimated to take 30-50 years.

Superfund and Your Property

If you own a home within the Superfund site, you have no liability for the contamination caused by others. Arizona has its own mini-Superfund law that protects innocent homeowners from cleanup liability.

However, if you are selling a home within the NIBW Superfund site, you must disclose the home is in a Superfund site to potential buyers. Whether disclosure is made by the seller or a real estate agent, the Superfund designation should be disclosed at the first discussion about the property. This will avoid any last-minute questions that could complicate the transaction. If you aren’t sure if your home is within the site, please call 480-312-8712.

For More Information

Contact Information

City of Scottsdale - Scottsdale Water
9312 N. 94th St.
Scottsdale, AZ 85258 
P: 480-312-5650
F: 480-312-5615

Office Hours

Monday through Friday
7 a.m. to 4:30 p.m.

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