Facts about the Environmental Protection Agency's Toxics Release Inventory and APS' participation in the program:
Q. What chemicals are measured?
There are more than 650 chemicals and compounds that the EPA says reporting industries must monitor as part of the TRI regulations. Of the 35 TRI chemicals typically produced at power stations that burn coal or oil, APS reported releases of 13 from its coal power plant operations. Four Corners reported all 13 chemicals; Cholla reported nine of them.
Q. Why did APS report so few chemicals?
A. Companies subject to TRI regulations must report only those chemicals that are released in amounts above 25,000 pounds a year. The type of coal that APS burns produces no more than 13 TRI chemicals - primarily metal compounds - in amounts beyond that threshold.
Q. Does APS monitor for all 650 TRI chemicals?
A. We measured the TRI chemicals known to result from fossil fuel combustion to determine those that exceed EPA’s threshold. We will continue to monitor the use of other chemicals at APS facilities to make sure we are meeting all TRI standards. We surveyed all the chemicals to see if we otherwise use them in excess of 10,000 pounds a year.
Q. What are the chemicals APS reported?
A. Both Four Corners and Cholla reported these metals: barium, chromium, copper, lead, nickel and manganese. Four Corners additionally reported beryllium, cobalt, selenium and zinc. Both power stations reported hydrochloric, hydrofluoric and sulfuric acids. These and other chemicals have always been produced by burning coal, oil and other fossil fuels.
Q. Are these chemical releases safe?
A. Yes. The TRI chemicals we reported are not harmful in the concentrations that exist at our plants. EPA’s own studies conclude that health risks relative to the volume of substances emitted from power plants are low. We burn about 15 million tons of coal at these facilities each year. But only 2,500 tons of these chemical substances are released, and the majority of these releases are actually metal compounds locked in the ash that we manage on site.
An assessment done by Harvard University’s Center for Risk Analysis concludes that, "Although this industry will report large quantities of emissions, the resulting risk to public health is minimal."
Q. Where do TRI chemicals go when plants are operating?
A. Most of them are metals chemically bound to the fly ash and bottom ash left over after coal is burned. Fly ash and bottom ash are similar to the ash you find in your fireplace. A small amount of the acid gases is released through the stacks after the gases are neutralized in our scrubbers.
APS, along with other utilities owning an interest in Four Corners and Cholla, has invested more than $750 million in pollution control technology to ensure any releases to the environment are kept at safe levels that fall well within regulated standards.
Q. What happens to the ash?
A. At APS, we either sell the ash, transfer it to ash ponds near the plants or return it to the coal mines where the material originated. The ash we sell to cement manufacturers is part of a recycling program and is not reportable under TRI. However, chemicals in the ash returned to the mines will be reported by us and reported a second time by the mines. There are no mines near Cholla - we ship our coal in by rail - so the ash cannot be reclaimed.
At both Four Corners and Cholla, less than half a percent of the ash is released through the stacks into the atmosphere. Both facilities sell some of the ash for use by cement manufacturers. Cholla sells about half of the ash it generates - or the equivalent of 5.5 million bags of cement. Four Corners sells about 10 percent of it - 4 million bags of cement - and sends about 70 percent back into the mine pits. The rest of the ash at both plants is placed in ash ponds on site.
Q. Does TRI data include the effects of these chemicals?
A. No. The TRI report released by EPA is a summary of chemical releases by weight. It does not address possible health or environmental risks associated with these releases, which may lead to public misunderstanding about the relatively small impact these substances have on the areas around APS facilities. EPA, EPRI and Harvard University have concluded in their studies that these substances, in the concentrations they are released, are not harmful to the environment in which we live.
Q. Why is the public just finding out about this now?
A. Environmental information - such as certain emissions and the kinds of substances that result from burning coal - has been available to the public for decades. Until now, however, the government has not asked utilities to measure these chemicals and report the results. As a steward of the environment, we are glad to comply.
This is not a new law, it’s just new to utilities at this time. As evidenced by the fact that TRI expanded to include utilities 10 years after its inception, this is a flexible regulation that could change again in the future. It could grow to include still more industries. Levels of detail required of reporting industries, or thresholds of reportable chemicals, could also change.
Q. What about APS' other power stations?
A. APS operates eight power stations with a total of 39 generating units in Arizona and New Mexico, ranging from one to eight units per site. About 55 percent of our energy mix is coal, about 35 percent is nuclear and the rest is comprised of natural gas, oil and hydro. We also operate the first two commercial solar facilities in Arizona and plan to build more.
EPA/APS Right to Know Program
1998 Reportable Releases
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