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Frequently Asked Questions
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Frequently Used Terms
About the Site
· Who pays to clean up a Superfund site?
· Where is the NIBW Superfund site?
· What is the history of the NIBW Superfund site?
· Who are the key entities involved in the NIBW Superfund site and what is their role?
· What is the current status of the Superfund cleanup activities?
· How long will the Superfund cleanup activities take?
Treatment Facility Information
· How do I find out if the water I'm being served is from the CGTF?
· How do you know the water from the CGTF is safe?
Superfund and Your Property
· If my property is within the Superfund site, do I need to disclose that fact when selling my home?
· Are homeowners liable for cleanup costs?
Frequently Used Terms:
ADEQ = Arizona Department of Environmental Quality = A State of Arizona agency that oversees groundwater quality.
CGTF = Central Groundwater Treatment Facility = The water treatment plant, which is owned and operated by the City of Scottsdale, that treats groundwater that contains TCE.
NIBW = North Indian Bend Wash = The area in Scottsdale over the plume of contamination, as designated by the USEPA.
TCE = Trichloroethylene = A colorless liquid that is used as a solvent for cleaning metal parts. TCE levels in drinking water are regulated by the USEPA and ADEQ.
USEPA = United States Environmental Protection Agency = A federal agency that oversees health regulations as they relate to drinking water.
About the Site
The federal Superfund law was created to provide funding and regulatory authority for the USEPA study and cleanup of contaminated sites throughout the country. According to the USEPA, there are five federal Superfund sites, including Scottsdale’s NIBW site, in the Phoenix metro area.
Who pays to clean up a Superfund site?
In short, Superfund policy is to “let the polluter pay.” In the case of the NIBW Superfund site, this refers to the three companies deemed potentially responsible for the contamination—Motorola, Inc.; GlaxoSmithKline (formerly SmithKline Beecham); and SMI Holding LLC (formerly Siemens).
Where is the NIBW Superfund site?
The site is designated by the USEPA as the area over the plume of contamination, as indicated on the map provided by the USEPA. To view the map click here (PDF/5.5MB/1 page). If you aren’t sure if your home is within the site, please call (480) 312-8743.
What is the history of the NIBW Superfund site?
Groundwater contamination at NIBW was discovered in 1981 when industrial chemicals, primarily TCE, were found in several Scottsdale-area drinking water wells. As a result, local water providers stopped using those wells for drinking water purposes. The USEPA identified the potentially responsible parties causing the contamination and determined that a long-term cleanup effort would be required.
Who are the key entities involved in the NIBW Superfund site and what is their role?
- USEPA = Monitors the contamination plume, identifies those parties potentially causing the contamination, establishes a cleanup remedy, and directs the cleanup of the site.
- State of Arizona – ADEQ and Arizona Department of Water Resources (ADWR) = Oversee the cleanup for the state.
- Potentially Responsible Parties (as designated by the USEPA) - Motorola, Inc., GlaxoSmithKline and SMI Holding LLC = Responsible for costs associated with the cleanup.
- City of Scottsdale (the drinking water provider) = Operates the CGTF and ensures the water produced by the plant meets or surpasses all federal and state standards for safe and healthful drinking water.
What is the current status of the Superfund cleanup activities?
In December 2006, the USEPA declared that construction was complete on all treatment facilities needed to prevent unsafe levels of contaminants from entering the drinking water supply. Four treatment facilities have been constructed in the Scottsdale area, as well as two in Tempe. In 2005, these facilities treated 5.8 billion gallons of water, or 16 million gallons a day.
How long will the Superfund cleanup activities take?
It has been estimated that the cleanup will take 30-50 years. However, large portions of the groundwater plume cleanup should be completed before that time.
Treatment Facility Information
The CGTF is owned and operated by the City of Scottsdale. The plant, located at Pima and Thomas roads, was built by the potentially responsible parties. The plant treats water pumped from four groundwater wells that contain TCE. The water is treated to federal and state drinking water standards, under the oversight of the USEPA in cooperation with ADEQ.
How does the CGTF work?
| The treatment facility uses a proven process that “strips” the water of contaminants by mixing it with air. Water pumped from the four wells filters down through three treatment columns. As the water and air mix, the contaminants attach themselves to the air. The treated water is then moved to a reservoir for final treatment before it is delivered to the City of Scottsdale drinking water system. The water in the reservoir is combined with other treated water sources to meet customer demand. The air used in the treatment process is passed through activated carbon filters to remove the contaminants before it is released. |  |
How do I find out if the water I’m being served is from the CGTF?
The map that shows the plume also indicates an outline of the CGTF service area. Please note that these boundaries change slightly based on seasonal water demands.
How do you know the water from the CGTF is safe?
All water provided by the City of Scottsdale consistently meets or surpasses federal and state drinking water standards. These standards are set to protect the public against substances that may be harmful to humans if consumed for long periods of time. The City of Scottsdale operates the CGTF above and beyond normal operating procedures approved by the USEPA and ADEQ. The facility removes TCE from the water to a non-detect level (less than 0.5 parts per billion), which is far below the standard of 5 parts per billion. For information on the quality of any water served by the City of Scottsdale, see the latest Water Quality Report or call (480) 312-8732 for a copy.
Superfund and Your Property
If my property is within the Superfund site, do I need to disclose that fact when selling my home?
Yes. 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) 312-8743.
Are homeowners liable for cleanup costs?
No. Homeowners face no liability for contamination caused by others at Superfund sites. Most of Arizona's federal Superfund sites involve groundwater contamination resulting from the disposal of industrial solvents by industrial facilities. In many instances, this water contamination has moved beyond the facilities’ boundaries to the aquifers under residential property. Sellers or buyers of residential property who have not caused or contributed to the contamination are not liable for the cleanup. In addition to the federal law, Arizona has its own mini-Superfund law which protects innocent homeowners from cleanup liability.
For More Information
- Craig Miller, City of Scottsdale Water Resources, (480) 312-8743
- Rachel Loftin, US EPA, (415) 972-3253 or (800) 231-3075
- Wendy Flood, ADEQ, (602) 771-4410 or, toll free, at (800) 234-5677
- USEPA Region IX Web site
- ADEQ Web site
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