MOJAQMD RULE 903 STDS.FOR FOSSIL FUEL-FIRED STEAM GEN.          
LAST REVISED 12/03/76
          
          (Adopted: December 3, 1976)

                                       Rule 903
                            Standards of Performance for
                          Fossil Fuel-Fired Steam Generators

          (a)  Definitions

               (1)  FOSSIL FUEL-FIRED STEAM GENERATING UNIT means a furnace
                    or  boiler  used  in the process of burning fossil fuel
                    for the purpose of producing steam by heat transfer.

               (2)  FOSSIL FUEL means natural gas, petroleum, coal, and any
                    form of solid, liquid,  or  gaseous  fuel  derived from
                    such materials for the purpose of creating useful heat.

          (b)  Emission Standard.

               This rule applies to all fossil fuel-fired steam  generating
               units,  the construction, modification or reconstruction  of
               which commenced  after  August  17,  1971,  or  more than 63
               million kilogram calories (250 million B.T.U.) per hour heat
               input.   Any  change to an existing fossil fuel-fired  steam
               generating  unit  to  accommodate  the  use  of  combustible
               materials, other  than fossil fuels as defined in this rule,
               shall not bring that  unit  under  the applicability of this
               rule.

               (1)  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:

                    (A)  Contain particulate matter in excess of 0.18 grams
                         per million calories (0.10 lb. per million B.T.U.)
                         heat input derived from fossil fuel.

                    (B)  Exhibit  20 percent opacity or greater except that
                         a  maximum   of   40   percent  opacity  shall  be
                         permissible for not more  than  two minutes in any
                         one hour.

               (2)  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   subject   to  the
                    provisions  of  this  rule shall cause to be discharged
                    into  the atmosphere from  any  affected  facility  any
                    gases which contain sulfur dioxide in excess of:
                    
                    (A)  1.4  grams  per  million  calories  (0.80  lb  per
                         million B.T.U.) heat input when liquid fossil fuel
                         is burned.

                    (B)  2.2  grams  per  million  calories  (1.2  lbs. per
                         million B.T.U.) heat input when solid fossil  fuel
                         is burned.

                    (C)  Where    different   fossil   fuels   are   burned
                         simultaneously  in any combination, the applicable
                         standard shall be  determined  by  proration using
                         the following formula:

                                        Y (0.80) + z (1.2)
                                        ------------------
                                               y + z

                         where

                         y is the percent of total heat input  derived from
                         liquid fossil fuel,

                         and

                         z is the percent of total heat input derived  from
                         solid fossil fuel.

                    (D)  Compliance shall be based on total heat input from
                         all fossil fuels burned, including gaseous fuels.

               (3)  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   subject   to  the
                    provisions  of  this  rule shall cause to be discharged
                    into  the atmosphere from  any  affected  facility  any
                    gases which  contain nitrogen oxides, expressed as NO2,
                    in excess of:

                    (A)  0.36 grams  per  million  calories  (0.20  lb. per
                         million  B.T.U.)  heat  input  when gaseous fossil
                         fuel is burned.

                    (B)  0.54  grams  per million calories  (0.30  lb.  per
                         million B.T.U.) heat input when liquid fossil fuel
                         is burned.

                    (C)  1.26 grams per  million  calories  (0.70  lb.  per
                         million  B.T.U.) heat input when solid fossil fuel
                         (except lignite) is burned.


                    (D)  Where   different    fossil   fuels   are   burned
                         simultaneously in any  combination, the applicable
                         standard shall be determined  by  proration  using
                         the following formula:

                                        x (0.20) + y (0.30) + z (0.70)
                                        ------------------------------
                                              x + y + z

                         where

                         x  is the percent of total heat input derived from
                         gaseous fossil fuel,

                         y is  the percent of total heat input derived from
                         liquid fossil fuel,

                         and

                         z is the  percent of total heat input derived from
                         solid fossil fuel (except lignite).

          (c)  Monitoring

               (1)  There shall be installed,  calibrated,  maintained, and
                    operated,  in  any  fossil fuel-fired steam  generating
                    unit subject to the provisions  of  this part, emission
                    monitoring instruments as follows:

                    (A)  A photoelectric or other type smoke  detector  and
                         recorder,  except  where  gaseous fuel is the only
                         fuel burned.

                    (B)  An  instrument  for  continuously  monitoring  and
                         recording sulfur dioxide  emissions,  except where
                         gaseous  fuel  is  the only fuel burned, or  where
                         compliance is achieved  through  low  sulfur fuels
                         and  representative  sulfur analysis of fuels  are
                         conducted daily in accordance  with  paragraph (3)
                         or  (4)  of  this  section.  Analysis of all  fuel
                         received  may  be  substituted   for   daily  fuel
                         analysis if this will assure accurate knowledge of
                         sulfur content of fuel as burned.  When fuels must
                         be blended to achieve compliance, sulfur  analysis
                         of   fuels  may  not  be  used  and  SO2  emission
                         monitoring is required.

                    (C)  An  instrument  for  continuously  monitoring  and
                         recording emissions of nitrogen oxides.

                    (D)  An  instrument  for  continuously  monitoring  and
                         recording  emissions  of  either  oxygen or carbon
                         dioxide in the flue gases.

               (2)  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 60.45, and 40 CFR 60 Appendix B.

               (3)  The sulfur content of solid fuels, as burned, shall  be
                    determined  in accordance with the following methods of
                    the American Society for Testing and Materials.

                    (A)  Mechanical sampling by Method D 2234-65.

                    (B)  Sample preparation by Method D 2013-65.

                    (C)  Sample analysis by Method D 271-68.

               (4)  The sulfur content of liquid fuels, as burned, shall be
                    determined in  accordance with the American Society for
                    Testing and Materials  Methods  D 1551-68, or D 129-64,
                    or D 1552-64.

               (5)  The rate of fuel burned for each fuel shall be measured
                    daily  or  at  shorter  intervals  and  recorded.   The
                    heating  value  and  ash  content  of  fuels  shall  be
                    ascertained at least once per week and recorded.   When
                    the   steam   generating   unit  is  used  to  generate
                    electricity,  the  average electrical  output  and  the
                    minimum and maximum  hourly  generation  rate  shall be
                    measured and recorded daily.

               (6)  For  the  purpose of reports required pursuant to  Rule
                    902(a), periods  of  excess  emissions  that  shall  be
                    reported are defined as follows:

                    (A)  Opacity.   All  hourly  periods during which there
                         are  three  or more one-minute  periods  when  the
                         average opacity equals or exceeds 20 percent.

                    (B)  Sulfur  dioxide.   Any  three-hour  period  during
                         which the average emissions (arithmetic average of
                         three  continuous   one-hour  periods)  of  sulfur
                         dioxide  as measured by  a  continuous  monitoring
                         system exceed the applicable emission standard.

                    (C)  Nitrogen oxides.   Any  three-hour  period  during
                         which the average emissions (arithmetic average of
                         three  continuous  one-hour  periods)  exceed  the
                         applicable emission standard.
          
          (d)  Test Procedures

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