APS’s waste programs cover many different areas, from power plant operation to transmission and distribution to service centers and field operations. APS is focused on the following waste-related regulatory issues:

Waste Trends

Coal Combustion Residual Rule

In accordance with EPA’s Coal Combustion Residual (“CCR”) rule, APS has installed monitoring wells around its coal ash impoundments. APS is on track to complete the required monitoring by October 2017 and at that time will determine next steps. Compliance with the CCR requirements will help APS characterize the integrity of its impoundments and their effect on groundwater, if any. APS has completed a full assessment of its coal ash impoundments and has determined that there are no underground conveyances that would allow the inadvertent discharge of coal ash.

Superfund-Related Matters

On September 3, 2003, EPA advised APS that EPA considers APS to be a potentially responsible person (PRP) in the Motorola 52nd Street Superfund Site, Operable Unit 3 ("OU3") in Phoenix, Arizona. APS has facilities that are within this Superfund site. APS and Pinnacle West have agreed with EPA to perform certain investigative activities of the APS facilities within OU3. In addition, on September 23, 2009, APS agreed with EPA and one other PRP to voluntarily assist with the funding and management of the site-wide groundwater remedial investigation and feasibility study work plan ("RI/FS"). The OU3 working group parties have agreed to a schedule with EPA that calls for the submission of a revised draft RI/FS by June 2017.

On August 6, 2013, the Roosevelt Irrigation District ("RID") filed a lawsuit in Arizona District Court against APS and 24 other defendants, alleging that RID’s groundwater wells were contaminated by the release of hazardous substances from facilities owned or operated by the defendants. The lawsuit also alleges that, under Superfund laws, the defendants are jointly and severally liable to RID. The allegations against APS arise out of APS’s current and former ownership of facilities in and around OU3. As part of a state governmental investigation into groundwater contamination in this area, on January 25, 2015, ADEQ sent a letter to APS seeking information concerning the degree to which, if any, APS’s current and former ownership of these facilities may have contributed to groundwater contamination in this area. APS responded to ADEQ on May 4, 2015. On December 16, 2016, two RID contractors filed ancillary lawsuits for recovery of costs against APS and the other defendants. We are unable to predict the outcome of these matters.