MEMORANDUM

TO:  Portland Cement MACT Docket

FROM:  Steven Silverman, Attorney, OGC

RE:  Telephone call with Portland Cement Ass’n (PCA) Nov. 16, 2006

On Nov. 16, Keith Barnett, Steve Fruh, and I spoke with Andy O’Hare of
PCA, and Fran Streitman of Ashgrove Cement and Tim Matz of Lehigh Cement
regarding potential developments in the Portland Cement MACT rule.  Each
HAP was discussed separately.

THC

PCA asked for a reaction to their suggestion of using a 112 (d) (4)
approach for hydrocarbons, and the risk assessment information they had
furnished to us.  We noted that section 112 (d) (4) is limited to
threshold pollutants, and that organic HAP emitted by cement kilns
include nonthreshold pollutants.  PCA also inquired whether the
risk-based subcategory approach used in plywood MACT might be an option.
 We explained that that rule had considered all HAP emitted by the
source category, and that PCA had supplied information only on
non-dioxin organic HAP.  To fit the plywood MACT template, information
would be needed on dioxin, and all metal HAP.

They also inquired about potential new source standards.  We discussed
use of a Thermal Oxidizer on one existing kiln, as well as the level of
performance EPA had considered in other rules that such a device
typically achieved.  PCA inquired about the possibility of a midport
sampling option, which we had thought not feasible based on earlier
conversations with PCA.  We also noted that midport sampling would only
reflect hydrocarbon destruction for fuel-related organics, not those in
the feed (which predominate).  Feed-related organics would be controlled
by a thermal oxidizer.  PCA noted the adverse energy implications of use
of a thermal oxidizer.

Mercury

PCA explained that cement kiln dust is not recycled back to the kiln for
reasons other than alkali levels.

There was some discussion of wet scrubber performance for mercury.  We
indicated we had obtained some outlet data for mercury but had no inlet
data.  PCA observed that outlet emission levels could reflect low
mercury concentrations in raw materials.

PCA inquired about our reaction to their suggestion of importing the
mercury standard for hazardous waste cement kilns, but we stated that
that limit reflects feed control of mercury in hazardous waste fuels,
and so is not related to performance of a non-hazardous waste kiln.

PCA confirmed that new sources will be equipped with in-line raw mills. 
They estimated that these mills would be off for 10-20% of the time the
cement kiln operates both because they require more maintenance and
because mill capacity exceeds kiln capacity.

PCA inquired about a potential standard greenfield standard reflecting
choice (through siting) of lower mercury feedstock, but did not offer
any basis for quantifying what ‘lower mercury feedstock’ would be.  
 

PCA also indicated that it is hard to determine which areas have high or
low-pyrite limestone (which influences SO2 emissions).  There can even
be substantial variability of pyrite levels within a quarry.

