April 15, 1991


MEMORANDUM

SUBJECT:  Revised ASARCO, East Helena Modeling Protocol

FROM:     Joseph A. Tikvart, Chief
          Source Receptor Analysis Branch (MD-14)

TO:       Douglas M. Skie, Chief
          Air Programs Branch, Region VIII (8AT-AP)


     In response to your request the Model Clearinghouse has
reviewed the subject protocol, dated March 11, and the April 11
Mindy Mohr comments on that protocol.  We find that Mindy's
comments well reflect our own concerns and we agree with her
viewpoints.

     If you have any further questions please contact Dean Wilson
at 629-5683 or me at 629-5562.

cc:  E. Ginsburg
     W. Laxton
     M. Mohr
     L. Ostrand