Utility MACT Pre-Comment Webinar on June 9

We had an excellent discussion of the proposed Utility MACT rule during yesterday’s Hot Topic Webinar. The 80+ participants included representatives from utilities, boiler and scrubber manufacturers, instrumentation vendors and governmental agencies. We are planning a follow-up Webinar in two weeks, just before the July 5 due date for comments. If you would like a topic or issue discussed, please let us know. We welcome your ideas for our second pre-comment Webinar scheduled for June 23.

It was pointed out during this week’s session that EPA had acknowledged a conversion error and was revising the MACT floor values for mercury upward, from 1.0 lb/TBtu to 1.2 lb/TBtu and from 0.008 lb/GWh to 0.013 lb/GWh for existing units. With respect to HCl, EPA assumes that the less expensive dry sorbent injection (DSI) technology can be used rather than scrubbers.  Participants thought that DSI technology could probably achieve the HCl standards with certain optimized hydrate products.  Others wondered whether DSI would just be a short-term solution only to be obsolesced by ambient PM_2.5, and SO₂ limits.

We also discussed the ability to consistently and reliably measure mercury, HCl and total particulate matter to the proposed levels. The HCl limit translates to 1.4 ppm, but instruments may only be reliable above 2 ppm. With respect to mercury, the method protocols are not designed for such low levels. Particulate matter offers its own challenges with respect to measuring the condensable fraction.