2003 Spill Summary

Oil Spills

• In April, a large PCB capacitor in the Show Low Substation ruptured and released approximately three gallons of PCB mineral oil onto the station's gravel bed. The contaminated soil and gravel was excavated and disposed of, and PCB contamination removed.
•  In July, a PCB contaminated transformer caught fire and exploded in Phoenix. About 10 gallons of contaminated oil spread over three residential properties due to high winds and water sprayed on the burning equipment by the local fire department. The properties were cleaned up and all visible oil removed.
•  In Phoenix, a PCB contaminated transformer failed during a summer monsoon storm in July. Approximately 10 gallons of oil was released and was washed by rainwater into a nearby dry well. In addition, oil also ran onto the adjacent property contaminating electronic equipment located on that site. All contaminated soil/asphalt and sludge in the drywell was removed. 
• In November, approximately 20 gallons of hydraulic oil were released into a City of Peoria street from a leaking hydraulic line on a Company service truck. The oil was carried into a storm drain by runoff from a sprinkler system watering nearby landscaping.
• An estimated one gallon of PCB was released in September onto the gravel bed at the APS Navajo switchyard when two high voltage capacitors ruptured. The contaminated soil and gravel was excavated and disposed of, and all PCB contamination removed.
• In November, about 100 gallons of non-PCB containing mineral oil was released from two transformers damaged in Payson when an excavation contractor accidentally dug into a buried electrical conduit line. The material was cleaned up and all visible oil removed.
   

Chemical Spills

• Approximately 50 to 60 gallons of EDTA boiler cleaning solution leaked into a drain at the Four Corners Power Plant in April. The material flowed under the cover of the drain and into the combined waste water treatment pond.
• In August, approximately 1,300 gallons of sulfuric acid were released from ruptured acid transfer line at the Saguaro Power Plant. The acid ran into the plant's storm drain system and into an unlined permitted surface impoundment. The acid spill was neutralized and storm drain system flushed to remove residual pockets of acid. The pH in the surface impoundment was closely monitored and returned to normal levels once the acid was neutralized.
• During a chemical cleaning process at the Four Corners Power Plant in November, a flange on the chemical cleaning discharge line leaked. Approximately three gallons of spent ammoniated EDTA solution was released into the Plant's condenser cooling water canal.
• In December, a 69kV bushing containing an estimated two gallons of PCB compound failed at the Prescott City Substation. The resulting explosion caused fragments of the PCB compound to be dispersed over a 100-foot area within the substation. All of the PCB compound material was cleaned up and soil within the immediate vicinity of the ruptured bushing was removed and disposed.

Other Releases

• A siphon water vacuum-vent valve on the Cholla Power Plant bottom ash pipeline failed after it froze and released approximately 9,000 gallons of water into the nearby Tanner Wash in December. The water soaked into the soil and no response action was necessary.
• Approximately 120,000 gallons of bottom ash sluice water was accidentally released from a hydro-bin at the Four Corners Power Plant in January. The water/ash mixture flowed into a storm-water containment area. The compacted earthen berm subsequently failed and allowed the water to flow into the plant's cooling water inlet canal.
• As the cooling towers at the Palo Verde Nuclear Generating Station were taken out of service in March 2003, there was a release of approximately 50,000 gallons of cooling-tower water to the ground. About 50 gallons of this overflow entered the Sedimentation Basin 1 unlined ditch.
  
  

Spill History

(a) 57,000 gallons overflowed from cooling tower flowed into unlined ditch at Palo Verde Plant. 4,000 gallons overflowed the cooling towers and released to the sedimentation basin at Palo Verde Plant. Less than 500 gallons of reverse osmosis product water was released on-site to the unlined ditch at Palo Verde Plant. 72,000 gallons of overflow from a cooling tower reached the sedimentation basin and unlined dirt storm drains at Palo Verde Plant.

(b) 50 gallons of sewage discharged into Morgan Lake at Four Corners Power Plant.

(c) In separate incidents, 340,000 gallons of water from a cooling tower spilled into an unlined retention basin at Palo Verde.  Approximately 500 gallons of effluent was released accidentally into the Palo Verde storm drain system. The West Phoenix Power Plant released about 8,900 gallons of cooling water into a nearby unlined retention basin. 

(d) A circulating cooping water line at the Cholla Power Plant cracked and leaked approximately 60,000 gallons of Cholla Lake water into the Little Colorado River. The water soaked into the dry streambed.

(e) 25 gallons of sulfuric acid discharged into a sump at the Four Corners Power Plant. About 37,500 gallons of chlorinated secondary treated effluent water was released to a sedimentation basin.

(f) 200 gallons of water containing slurried bottom ash were released into a dry streambed at the Cholla Power Plant when a bottom ash pipeline ruptured. About 500 gallons of water containing ash were released when a discharge pipe ruptured. A blowdown reuse pipe was damaged and 8,045 gallons of water was released at the Palo Verde Plant, 4,000 gallons were recovered.

(g) 7,300 gallons of non-radioactive water were released to an unlined storm water drain. About 31,000 gallons of water from a HVAC cooling tower were released into and unlined storm water ditch.

(h) 280 gallons of water was released from a spray pond filter at Palo Verde. Three separate discharges at Four Corners, two of 100 gallons each and one of unknown quantity.