MOJAQMD RULE 906 STD. FOR NITRIC ACID PLANTS          
LAST REVISED 12/03/76

          
          (Adopted: December 3, 1976)

                                       Rule 906
                             Standard of Performance for
                                  Nitric Acid Plants


          (a)  Definitions

               (1)  NITRIC   ACID   PRODUCTION   UNIT  means  any  facility
                    producing weak nitric acid by  either  the  pressure or
                    atmospheric pressure process.

               (2)  WEAK  NITRIC ACID means acid which is 30 to 70  percent
                    in strength.

          (b)  Emission Standard

               This rule applies  to  nitric acid plants, the construction,
               modification  or reconstruction  of  which  commenced  after
               August 17, 1971.

               On and after the date on which the performance test required
               to be conducted by Rule 902 (b)(1) is completed, no owner or
               operator of a facility  subject  to  the  provisions of this
               rule  shall cause to be discharged into the  atmosphere  any
               gases which:

               (1)  Contain nitrogen oxides, expressed as NO2, in excess of
                    1.5  kilograms  per metric ton (3 lbs. per ton) of acid
                    produced, the production being expressed as 100 percent
                    nitric acid.

               (2)  Exhibit ten percent opacity or greater.

          (c)  Monitoring

               There  shall  be  installed,   calibrated,  maintained,  and
               operated, in any nitric acid production  unit subject to the
               provisions  of  this  rule,  an instrument for  continuously
               monitoring and recording emissions of nitrogen oxides.

               Monitoring instruments and sampling  systems  installed  and
               used   pursuant   to   this  section  shall  be  subject  to
               requirements and performance specifications in 40 CFR 60.13,
               40 CFR 60.73, and 40 CFR 60 Appendix B.

               Production rate and hours  of  operation  shall  be recorded
               daily.

               For the purpose of making written reports pursuant  to  Rule
               902  (a)  periods of excess emissions that shall be reported
               are defined  as  any  three-hour period during which average
               nitrogen  oxides  emissions  (arithmetic  average  of  three
               contiguous one-hour  periods)  as  measured  by a continuous
               monitoring system exceed the applicable emission standard.

          (d)  Testing Procedure

               Emissions shall be tested according to the methods specified
               by the Air Pollution Control Officer.

          (e)  Monitoring

               There  shall  be  installed,  calibrated,  maintained,   and
               operated,  in  any  sulfuric acid production unit subject to
               the provisions of this  rule, an instrument for continuously
               monitoring and recording emissions of sulfur dioxide.

               Monitoring instruments and  sampling  systems  installed and
               used  pursuant  to  this  section  shall  be subject to  the
               requirements and performance specifications in 40 CFR 60.13,
               40 CFR 60.84, and 40 CFR 60 Appendix B.

               Production  rate  and hours of operation shall  be  recorded
               daily.

               For the purpose of  making  written reports pursuant to Rule
               902 (a) periods of excess emissions  that  shall be reported
               are  defined  as  all three-hour periods (or the  arithmetic
               average of three consecutive  one-hour periods) during which
               the integrated average sulfur dioxide  emissions  exceed the
               applicable emission standard.

          (d)  Testing Procedure

               Emissions shall be tested according to the methods specified
               by the Air Pollution Control Officer