Potentially Responsible Party (PRP) Issues
APS was named in 2003 as a Potential Responsible Party in the Motorola 52nd Street Operable Unit 3 Superfund Site located in Phoenix, Arizona. In July 2004, APS completed negotiations with the EPA and signed a formal agreement, an Administrative Order of Consent. The agreement obligates APS to determine the extent, if any, of its contribution to the regional groundwater impacts, and if so, to identify options for addressing the company’s contribution to those impacts under the EPA’s oversight and guidelines.

APS is currently implementing the scope of work specified in the Administrative Order on Consent to evaluate potential groundwater impacts at our facility. The results of the groundwater investigation to date, indicate that volatile organic compounds have been detected in both the up and down gradient monitor wells at the APS facility at concentrations below the EPA’s Maximum Contaminant Level for drinking water. Additional characterization of the soil and groundwater are scheduled for 2007 to 2008.  

APS continues to provide funding for the clean-up of the EPA CERCLA Hassayampa Landfill superfund site. APS sent industrial solid waste to this municipal landfill until it closed in the late 1970s. The facility was later designated as a Federal superfund site and APS named as one of a number of PRPs. APS’ contribution to this clean-up effort is small, representing approximately 1.5 percent of the total annual assessment.

MGP Voluntary Remediation Program Status
Manufactured Gas Plants (MGPs) operated from the late 1800s to about 1950, making synthetic gas for domestic heating and lighting purposes. Several predecessors of APS operated plants in Arizona communities including Phoenix, Globe, Miami, Prescott, Douglas and Yuma. The manufactured gas process created by-products including lampblack, tar and oils, some of which remained at the sites after operations ceased.

APS has voluntarily investigated and characterized our historical MGP sites. We have entered the MPG sites into the Arizona Department of Environmental Quality Voluntary Remediation Program, which is a program specificallly addressing the voluntary investigation and remediation of environmentally impacted sites in Arizona. The company began evaluating each site in 1993 to address any remaining material that may have been generated by MGP activities. We began remediating the sites in 1996. Below is the current status of our MGP remediation sites:

Other Remediation Projects
The following table describes the current status of APS’ non-MGP remediation projects. Each of these sites is also anticipated to be completed under guidance of the Arizona Department of Environmental Quality (ADEQ) through the Voluntary Remediation Project.

Spill Summary
We take many precautions to avoid spills. However, despite our efforts, on occasion an accidental spill occurs. In 2006, APS had the following releases. These releases do not include small releases of non-PCB mineral oil from electrical equipment, or releases of water. 

(Note: releases to water are defined as materials that went into a Water of the USA, as defined in the federal regulations)

Oil Spills:

• Release of PCB oil from a Potential Transformer malfunction with the lid and bottom releasing approximately 3 gallons at our Four Corners Power Plant
• A Pothead was damaged and released between 600-1000 gallons of mineral oil inside a substation

Chemical Spills:

• Approximately 150 gallons of 10 percent sodium hypochlorite (bleach) leaked from the Cholla Power Plant lake storage/transport system onto the surrounding concrete/asphalt. The spill was completely contained on plant site 

Toxic Release Inventory
Our company is required by the Environmental Protection Agency (EPA) to report applicable releases of chemicals listed by the EPA through its Toxic Release Inventory (TRI) program. Our reportable releases under the TRI program are primarily contained in our air emissions from power plant smokestacks, or are contained within coal ash. While the TRI quantities reported by our company are fairly large (as is the case with all utility companies), the majority of these releases are captured by pollution control equipment, or are contained with our waste coal ash (much of which is recycled for beneficial use).  The below chart lists our 2005 TRI summary (2006 TRI report is due in July 2007 and was not available at the publication of this report)

Palo Verde Tritium
In February of 2006, Palo Verde personnel found tritium — a radioactive form of hydrogen ­— in shallow subsurface water around Unit 3. Although low levels of tritium were detected in water collected in shallow “potholes” excavated in the RCA yard, none has ever been detected in any wells or aquifers beneath the plant property or in offsite wells. The Arizona Department of Environmental Quality (ADEQ) and the Nuclear Regulatory Commission were notified in a “non-hazardous spill” report.

In response to the discovery, a team was formed to conduct exhaustive studies, establish the source of tritium and ultimately remediate the condition. The likely source was determined to be tritium from normal releases of plant gasses from which tritium was washed from the air by rain and from condensation from air ducts. Working closely with ADEQ, Palo Verde has enacted additional procedural controls and made physical changes, including drilling new monitoring wells,at the plant to enhance monitoring and minimize the potential for reoccurrence. During this same period, Palo Verde took an industry leadership role in defining proactive guidance on groundwater protection. Once approval is received from ADEQ, water trapped in the shallow sand lenses will soon be pumped out and eliminated.