Opinion ID: 1176318
Heading Depth: 2
Heading Rank: 2

Heading: The Nature and Extent of the Waste to be Evaluated

Text: In determining the radon-222 concentrations that would be produced by LRP and SL, EFSC considered only the top 30 centimeters of the waste as it existed when EFSC evaluated it. Petitioners argue that the rule requires all of the waste to be considered as of the time that it was placed in LRP and SL. Petitioners contend that by the time the characteristics of the waste were evaluated, several years after the waste was placed in the sludge ponds, the waste had been substantially diluted by the actions of wind and rain. Because gaseous radon-222 decays relatively rapidly into nongaseous elements, radon-222 produced below a certain depth in waste material will decay before it is able to reach the surface and escape into the atmosphere. EFSC determined that only the top 30 centimeters of LRP and SL emitted radon-222 into the atmosphere. Petitioners do not dispute that only a portion of the waste is currently responsible for emitting radon-222, but they argue that EFSC should have considered the characteristics of all of the waste because future disturbances of the waste  for instance, by construction on the waste or by moving the waste to another site  might bring waste at lower levels to the surface. If EFSC's order had the effect of determining for all time that TWCA's waste is not radioactive, we might be persuaded that EFSC had erred in considering only the top portion of the waste. But we do not so interpret EFSC's order. EFSC's evaluation of the waste is necessarily limited to the waste in its current form because many of the variables in the model EFSC used to predict radon-222 concentrations depend upon the peculiar features of LRP and SL, in particular climatic conditions such as average wind speed and average rainfall. Were the wastes located at another site, the radon-222 concentrations predicted by the model might be quite different. This interpretation of EFSC's order is in accord with the purpose to be served by OAR 345-50-035. The rule is intended to exempt from regulation waste that does not emit radiation into the environment in amounts sufficient to pose a threat to public health. See OAR 345-50-010(1). EFSC states in its order that if it were to consider the average characteristics of all of the waste, it might be forced to conclude that waste that emitted more than the threshold amount of radon-222 into the atmosphere was nonetheless not radioactive if lower levels of the waste produced a sufficiently small amount of radon-222. Given the purpose of the rule, EFSC's consideration of only that portion of the waste that emits radon-222 into the atmosphere is not an erroneous interpretation of the rule. If in the future TWCA's waste is disturbed so that lower, possibly more radioactive waste, is exposed, procedures are available by which EFSC can redetermine the radioactivity of the waste. See ORS 469.550 and ORS 469.570. Petitioners' argument that the waste should have been evaluated as of the time that it was placed in the sludge ponds relies on OAR 345-50-035(1), which provides: The [waste] material shall be considered in the form it exists when it is removed from the users' equipment, systems, or settling ponds prior to any dilution or remedial action designed to reduce radiation levels. OAR 345-50-035 applies not only to waste sites that are no longer accumulating waste, such as LRP and SL, but also to sites at which waste will be added in the future. See OAR 345-50-035(3). The prohibition on considering dilution or remedial action designed to reduce radiation levels is meant to make the evaluation of the radioactivity of the waste independent of remedial efforts that may not be performed in the future. Exposing to the elements waste that is no longer being accumulated is not a remedial measure of this sort because the absence of exposure in the future will not increase the release of radiation to the environment. Indeed, OAR 345-50-035 contemplates that waste will be considered when it is removed from settling ponds, presumably after exposure to the diluting effects of wind and water. We conclude that the rule does not require EFSC to reconstruct radiation levels that no longer exist.