Sounds Like Science

The EPA’s Office of Inspector General issued a report yesterday stating that the agency ignored scientific evidence and its own guidelines in order to develop mercury emission limits that would be consistent with the Bush administration's free-market approaches to controlling pollutants from power plants. Note that the press release was distributed on Friday – the traditional day for burying unpleasant news.

The key finding of the OIG’s report was, “[e]vidence indicates that EPA senior management instructed EPA staff to develop a Maximum Achievable Control Technology (MACT) standard for mercury that would result in national emissions of 34 tons annually, instead of basing the standard on an unbiased determination of what the top performing units were achieving in practice.”

The 34-tons-per-year target was based on the amount of mercury reductions expected to be achieved from implementation of nitrogen oxide (NOx) and sulfur dioxide (SO2 ) controls, rather than from implementation of control technologies specifically for mercury. According to EPA officials, 34 tons represents the most realistic and achievable standard for utilities.

However, MACT standards typically require all facilities to achieve emissions reductions achieved by the top performing 12 percent of facilities in the nation. The OIG stated that the 34 ton/year standard understated the average amount of mercury emissions reductions achieved by the top performing 12 percent of utilities – which is just about saying that the proposed standard doesn’t comply with the Clean Air Act.

The OIG also called into question the cost benefit of the desired cap-and-trade approach to emissions limitations compared with the MACT, and questioned the ability for the proposal to address mercury hot spots. In other words, a facility could achieve the standard by buying emissions credits, which would reduce overall mercury emissions and long-range transport, but still result in significant exposures to residents living near the facility. Finally, the OIG found that the rulemaking did not comply with certain Agency and Executive Order requirements, including not fully analyzing the cost-benefit of regulatory alternatives and not fully assessing the rule’s impact on children’s health.

The part of the story that was most interesting starts on page 13 of the report:

EPA documents and an analysis of the process used to compute the MACT floor support EPA staff’s statements that the MACT floor computations were developed to produce the desired national emissions of 34 tons per year. Documentation that we reviewed indicated that EPA conducted at least three Integrated Planning Model (IPM) runs in order to reach the pre-determined target for national mercury emissions of 34 tons. The initial IPM run to try to reach the 34-tons target yielded a national emission of 29 tons (i.e., the IPM model indicated that mercury could be reduced from 48 tons to 29 tons). After changing the proposed MACT emission limits, a second IPM model yielded a national emission of 27 tons. While we were provided summary information about these two IPM model runs, they were not included in the EPA rulemaking docket.

An Agency source indicated that these results were not acceptable to senior management because they were not close enough to the 34-tons target.

Shorter version: pick the target, then back the analysis into it.

Not taking enough consideration of the impact on children’s health is disturbing, because reducing mercury emissions is almost entirely about childrens’ health. Agency officials argued that reductions in emissions will reduce atmospheric mercury, would in turn result in less deposition, lower mercury levels in fish, and ultimately reductions in human exposure to mercury, though a detailed analysis of the risk reduction had not been done for the proposed rule. However, they hoped to have a more detailed assessment for the final rule. They further explained that the Notice of Data Availability issued in December 2004 proposed a process for quantifying the proposed rule’s impact on mercury deposition and the resulting bioaccumulation in the environment. So they proposed an emission limit without knowing if it would achieve any meaningful public health goals?