PLAAPCD RULE 231 IND.INSTITUTIONAL, AND COMM.BOILERS,ETC 
LAST REVISED 10/17/94

                             
                             Adopted 10-17-94

                                 CONTENTS


100  GENERAL

     101  APPLICABILITY
     102  EXEMPTION, BIOMASS BOILERS
     103  EXEMPTION, CEMENT AND LIME KILNS, GLASS MELTING
          FURNACES, AND SMELTERS
     104  EXEMPTION, DIRECT-CONTACT DRYERS
     105  EXEMPTION, ELECTRIC UTILITY BOILERS
     106  EXEMPTION, MEDICAL WASTE INCINERATORS
     107  EXEMPTION, MUNICIPAL WASTE INCINERATORS
     108  EXEMPTION, NONGASEOUS FUELS
     109  EXEMPTION, WASTE HEAT RECOVERY BOILERS

200  DEFINITIONS

     201  ANNUAL HEAT INPUT
     202  BOILER OR STEAM GENERATOR
     203  BRITISH THERMAL UNIT (BTU)
     204  GAS
     205  HEAT INPUT
     206  HIGHER HEATING VALUE (HHV)
     207  MUNICIPAL SOLID WASTE
     208  NOx EMISSIONS (NOx)
     209  NONGASEOUS FUEL
     210  PARTS PER MILLION BY VOLUME (PPMV)
     211  PROCESS HEATER
     212  RATED HEAT INPUT CAPACITY
     213  RESPONSIBLE OFFICIAL
     214  STANDARD CONDITIONS
     215  THERM
     216  THREE PREVIOUS CALENDAR YEARS
     217  UNIT

300  STANDARDS

     301  ANNUAL HEAT INPUTS  90,000 THERMS
     302  ANNUAL HEAT INPUTS < 90,000 THERMS
     303  EQUIPMENT REQUIREMENTS
     
400  ADMINISTRATIVE REQUIREMENTS

     401  COMPLIANCE SCHEDULE
     402  COMPLIANCE DETERMINATION
     403  COMPLIANCE COSTS
     404  CERTIFICATION
500  MONITORING AND RECORDS

     501  FUEL USAGE AND OPERATING HOURS
     502  SOURCE TESTS
     503  TUNING REPORTS
     504  DURATION OF RECORDS

600  TUNING PROCEDURE

     601  GENERAL
     602  PROCEDURES100  GENERAL

     
     
     101  APPLICABILITY:  This rule applies to boilers, steam
          generators, and process heaters with rated heat inputs of
          greater than or equal to 5 million BTU per hour, used in
          industrial, institutional, and commercial operations.

     102  EXEMPTION, BIOMASS BOILERS:  The provisions of this rule
          do not apply to boilers subject to Rule 232, BIOMASS
          SUSPENSION BOILERS, or Rule 233, BIOMASS BOILERS.

     103  EXEMPTION, CEMENT AND LIME KILNS, GLASS MELTING FURNACES,
          AND SMELTERS:  The provisions of this rule do not apply
          to cement and lime kilns, glass melting furnaces and
          smelters.

     104  EXEMPTION, DIRECT-CONTACT DRYERS:  The provisions of this
          rule do not apply to dryers in which the material being
          dried is in direct contact with the products of
          combustion.

     105  EXEMPTION, ELECTRIC UTILITY BOILERS:  The provisions of
          this rule do not apply to boilers used by electric
          utilities to generate electricity.

     106  EXEMPTION, MEDICAL WASTE INCINERATORS - This rule shall
          not apply to those incinerators which are subject to the
          requirements of Rule 906, AIRBORNE TOXIC CONTROL MEASURE
          - MEDICAL WASTE INCINERATORS.

     107  EXEMPTION, MUNICIPAL WASTE INCINERATORS - This rule shall
          not apply to boilers, steam generators, or process
          heaters whose primary purpose is to burn municipal solid
          waste, as defined in Section 206.

     108  EXEMPTION, NONGASEOUS FUELS:  Units subject to the
          requirements of Section 301 that normally burn only
          gaseous fuel shall comply with a 150 ppmv, or 0.215 pound
          per million BTU of heat input, NOx emission limitation
          when burning nongaseous fuel, if gas is unavailable for
          purchase.  This exemption is limited to not more than 168
          hours of operation per calendar year, excluding equipment
          and emission testing time not exceeding 48 hours per
          calendar year.

     109  EXEMPTION, WASTE HEAT RECOVERY BOILERS:  The provisions
          of this rule do not apply to waste heat recovery boilers
          that are used to recover sensible heat from the exhaust
          of combustion turbines.

200  DEFINITIONS

     201  ANNUAL HEAT INPUT - The total heat input of fuels burned
          by a unit in a calendar year, as determined from the
          higher heating value and cumulative annual usage of each
          fuel.

     202  BOILER OR STEAM GENERATOR - Any combustion equipment
          fired with any fuel and used to produce steam that is not
          used exclusively to produce electricity for sale.

     203  BRITISH THERMAL UNIT (BTU) - The amount of heat required
          to raise the temperature of one pound of water from 59F
          to 60F at one atmosphere.

     204  GAS - Any fuel which is a gas at standard conditions.    

     205  HEAT INPUT - The chemical heat released due to fuel
          combustion in a unit, using the higher heating value of
          the fuel.  This does not include the sensible heat of
          incoming combustion air.

     206  HIGHER HEATING VALUE (HHV) - The total heat liberated per
          mass of fuel burned (BTU per pound), when fuel and dry
          air at standard conditions undergo complete combustion
          and all resultant products are brought to their standard
          states at standard conditions.  HHV shall be determined
          by one of the following test methods:

          206.1     ASTM D 2015-85 for solid fuels; or

          206.2     ASTM D 240-87 or ASTM D 2382-82 for liquid
                    hydrocarbon fuels; or

          206.3     ASTM D 1826-88 or ASTM D 1945-81 in
                    conjunction with ASTM D 3588-89 for gaseous
                    fuels.

     207  MUNICIPAL SOLID WASTE - Household, commercial/retail,
          and/or institutional waste.  Household waste includes
          material discarded by single or multiple residential
          dwellings, hotels, motels, and other similar permanent or
          temporary housing establishments or facilities. 
          Commercial/retail waste includes material discarded by
          stores, offices, restaurants, warehouses,
          nonmanufacturing activities at industrial facilities, and
          other similar establishments or facilities. 
          Institutional waste includes material discarded by
          schools, hospitals, prisons, and government facilities
          and other similar establishments or facilities. 
          Municipal solid waste does not include landfill gas or
          digester gas or other fuels derived from decomposition of
          municipal solid wastes.

     208  NOX EMISSIONS (NOX) - The sum of nitric oxides and
          nitrogen dioxide in the flue gas, collectively expressed
          as nitrogen dioxide (NO2).

     209  NONGASEOUS FUEL - Any fuel which is not a gas at standard
          conditions.

     210  PARTS PER MILLION BY VOLUME (PPMV) - The ratio of the
          number of gas molecules of a given species, or group, to
          the number of millions of total gas molecules.

     211  PROCESS HEATER - Any combustion equipment fired with any 
          fuel, and which transfers heat from combustion gases to
          water or process streams.

     212  RATED HEAT INPUT CAPACITY - The heat input capacity, in
          million BTU per hour, specified on the nameplate of the
          combustion unit.  If the combustion unit has been altered
          or modified such that its maximum heat input is different
          than the heat input capacity specified on the nameplate,
          the maximum heat input shall be considered as the rated
          heat input.

     213  RESPONSIBLE OFFICIAL - An individual with the authority
          to certify that a source complies with all applicable
          requirements, including the conditions of permits issued
          to sources in accordance with Regulation 5, PERMITS.  A
          "responsible official" means one of the following:

          213.1     For a corporation, a president, secretary,
                    treasurer, or vice-president of the
                    corporation in charge of a principal business
                    function, or any other person who performs
                    similar policy or decision-making functions
                    for the corporation, or a duly authorized
                    representative of such person if the
                    representative is responsible for the overall
                    operation of one or more manufacturing,
                    production, or operating facilities applying
                    for or subject to a permit and either:
                    a.   The facilities employ more than 250
                         persons or have gross annual sales or
                         expenditures exceeding $25 million (in
                         second quarter 1980 dollars); or
                    b.   The delegation of authority to such
                         representative is approved in advance by
                         the Air Pollution Control Officer;

          213.2     For a partnership or sole proprietorship, a
                    general partner or the proprietor,
                    respectively; or

          213.3     For a municipality, state, federal, or other
                    public agency, either a principal executive
                    officer or a ranking elected official; or

     214  STANDARD CONDITIONS - For purposes of this rule, a gas
          temperature of 68 Fahrenheit and a gas pressure of
          14.7 pounds per square inch absolute.

     215  THERM - One hundred thousand (100,000) BTU.

     216  THREE PREVIOUS CALENDAR YEARS - The three consecutive
          years immediately preceding the year in which final
          compliance is required by this rule, or the three
          consecutive years immediately preceding each calendar
          year of compliance thereafter.

     217  UNIT - Any boiler, steam generator or process heater as
          defined in Sections 202 and 211.

300  STANDARDS

     301  ANNUAL HEAT INPUTS  90,000 THERMS:  For units with rated
          heat inputs of greater than or equal to 5 million BTU per
          hour and annual heat inputs of greater than or equal to
          90,000 therms for any three previous calendar years, NOx
          emissions shall not exceed the following levels:

          301.1     30 parts per million by volume (ppmv), or
                    0.036 pound per million BTU of heat input when
                    operated on gas; or

          301.2     40 parts per million by volume (ppmv), or
                    0.052 pound per million BTU of heat input,
                    when operated on nongaseous fuel; or

          301.3     The heat-input weighted average of the limits
                    specified in 301.1 and 301.2, above, when
                    operated on combinations of gas and nongaseous
                    fuels.

          301.4     Emissions from units subject to this section
                    shall not exceed a carbon monoxide
                    concentration of 400 parts per million by
                    volume (ppmv).

     302  ANNUAL HEAT INPUTS < 90,000 THERMS:  Units with rated
          heat inputs of greater than or equal to 5 million BTU per
          hour and annual heat inputs of less than 90,000 therms
          for each of the three previous calendar years shall be:

          302.1     Operated in a manner that maintains stack-gas
                    oxygen concentrations at less than or equal to
                    3.00 percent by volume on a dry basis; or

          302.2     Operated with a stack-gas oxygen trim system
                    set at 3.00 percent by volume oxygen.  The
                    tolerance of this setting shall be plus or
                    minus () five percent (i.e. 2.85 to 3.15
                    percent by volume oxygen); or

          302.3     Tuned at least once per year by a technician
                    that is qualified, to the satisfaction of the
                    Air Pollution Control Officer, to perform
                    tuning in accordance with Section 600; or

          302.4     Operated in compliance with the applicable
                    emission levels specified in Section 301.

     303  EQUIPMENT REQUIREMENTS

          303.1     For units which simultaneously fire
                    combinations of different fuels, and are
                    subject to the requirements of Section 301,
                    mass flow rate meters shall be installed in
                    each fuel line.  Alternatively, volumetric
                    flow rate meters may be installed in
                    conjunction with temperature and pressure
                    meters in each fuel line.

          303.2     For units which employ flue-gas NOx reducing
                    technology, and are subject to the
                    requirements of Section 301, meters, as
                    applicable, shall be installed to allow
                    instantaneous monitoring of the operational
                    characteristics of the NOx reduction
                    equipment.

400  ADMINISTRATIVE REQUIREMENTS

     401  COMPLIANCE SCHEDULE

          401.1     By January 1, 1995, any person subject to this
                    rule shall submit a plan containing the
                    following:
                    a.   A list of all units with their rated heat
                         inputs and anticipated annual
                         heat inputs.
                    b.   For each unit subject to Section 301, the
                         selected method of achieving compliance
                         with the applicable standards of Section
                         301.
                    c.   For each unit subject to Section 302, the
                         selected option (one of four specified in
                         Section 302) to achieve compliance with
                         that section.

          401.2     By May 31, 1995, any Major Source subject to
                    this rule shall demonstrate final compliance
                    with all applicable standards and requirements
                    of Section 300.  Subject to the approval of
                    the Air Pollution Control Officer, testing
                    conducted in the 18 months preceding May 31,
                    1995, may be used to demonstrate compliance
                    provided such testing meets the requirements
                    of Sections 503.1, using the test methods
                    specified in Section 502.

          401.3     By October 17, 1996, any non-Major Source
                    subject to this rule shall submit an
                    application for Authority to Construct for any
                    modifications required to achieve compliance
                    with the requirements of this rule.

          401.4     By October 17, 1997, any non-Major Source
                    subject to this rule shall demonstrate final
                    compliance with all applicable standards and
                    requirements of this rule.

          401.5     Any non-Major Source subject to this rule
                    installing a new or replacement boiler shall
                    comply with this rule for the new or
                    replacement boiler effective October 17, 1995.

          401.6     A violation of the plan required under Section
                    401.1 shall constitute a violation of this
                    rule.

     402  COMPLIANCE DETERMINATION:

          402.1     Any person subject to this rule shall have the
                    option of complying with either the pounds-
                    per-million-BTU emission rates or the parts-
                    per-million-by-volume emission limits
                    specified in Section 301.

          402.2     All ppmv emission limits specified in Sections
                    106 and 301 are referenced at dry stack-gas
                    conditions and 3.00 percent by volume stack-
                    gas oxygen.  Emission concentrations shall be
                    corrected to 3.00 percent oxygen as follows:

                         
                         

          402.3     All pounds-per-million-BTU emission rates
                    shall be calculated as pounds of nitrogen
                    dioxide (NO2) per million BTU of heat input.

     403  COMPLIANCE COSTS:  A person operating a unit subject to
          this rule shall bear all expenses associated with
          compliance with the monitoring and reporting provisions
          of this rule.

     404  CERTIFICATION:  All reports submitted in accordance with
          this rule shall be signed by a responsible official who
          shall certify the truth, accuracy, and completeness of
          the report.

500  MONITORING AND RECORDS

     501  FUEL USAGE AND OPERATING HOURS

          501.1     Any person subject to this rule shall monitor
                    and record for each unit the HHV and
                    cumulative annual usage of each fuel.

          501.2     The cumulative annual usage of each fuel shall
                    be monitored from utility service meters,
                    purchase, or tank fill records, or by any
                    other acceptable methods approved by the Air
                    Pollution Control Officer.

          501.3     Any person subject to this rule, but exempt
                    from Section 301 in accordance with Section
                    106, shall monitor and record for each unit
                    the cumulative hours of operation on each
                    nongaseous fuel.  The records shall be updated
                    weekly and made available to the District upon
                    request.

     502  SOURCE TESTS

          502.1     Except for units in compliance with the tuning
                    option of Section 302.3, a source test shall
                    be conducted for all units subject to this
                    rule to demonstrate compliance.  A report of
                    this source test shall include the operational
                    characteristics of any flue-gas NOx reduction
                    equipment.  Additional source testing may be
                    required by the Air Pollution Control Officer
                    as necessary to ensure compliance with the
                    standards set forth in Sections 301 and 302. 
                    Compliance source testing is required on an
                    annual basis for sources subject to Rule 507,
                    FEDERAL OPERATING PERMIT PROGRAM.

          502.2     All source tests shall be made in the as-found
                    operating condition, except that source tests
                    shall include at least one test conducted at
                    the maximum firing rate allowed by the
                    District permit, and no source test shall be
                    conducted within two hours after a continuous
                    period in which fuel flow to the unit is zero,
                    or shut off, for thirty minutes or longer.  A
                    separate source test shall be conducted for
                    each fuel burned including standby fuel.          502.3     Compliance with NOx emission requirements and
                    the stack-gas carbon monoxide and oxygen
                    requirements of Section 300 shall be
                    determined using the following test methods:
                    a.   Oxides of Nitrogen - ARB Method 100,
                         Title 17, CCR, Section 94114, Procedures
                         for Continuous Emission Stack Sampling.
                    b.   Carbon Monoxide - ARB Method 100.
                    c.   Stack-Gas Oxygen - ARB Method 100.
                    d.   NOx Emission Rate (Heat Input Basis) -
                         EPA Method 19, 40 CFR Part 60, Appendix
                         A.

          502.4     All emission concentrations and emission rates
                    shall be based on 15-consecutive-minute
                    averages.  These averages shall be calculated
                    from no less than five data sets, recorded
                    from samplings on intervals of no greater than
                    three minutes.

          502.5     Integrated sampling methods for oxides of
                    nitrogen, stack-gas oxygen, and stack-gas
                    carbon monoxide, as approved by the Air
                    Pollution Control Officer, may be acceptable
                    for determination of compliance with NOx
                    emission concentration or rate limits.

     503  TUNING REPORTS:  Units covered under Section 302.3 shall
          be tuned not less than once every 12 months.  Tuning
          verification reports shall be submitted not less than
          once every 12 months for each fuel burned.  The first
          tuning verification report shall be submitted by October
          17, 1997, for non-Major Sources, and by May 31, 1995, for
          Major Sources subject to this rule.

     504  DURATION OF RECORDS:  All records maintained pursuant to
          this rule shall be retained for at least three years from
          date of entry, with the exception that sources subject to
          the requirements of Rule 507, FEDERAL OPERATING PERMIT
          PROGRAM, shall retain records at least five years. 
          Records shall be made available for inspection by the Air
          Pollution Control Officer upon request.

600  TUNING PROCEDURE

     601  GENERAL: Nothing in this tuning procedure shall be
        construed to require any act or omission that would
        result in unsafe conditions or would be in violation of
        any regulation or requirement established by Factory
        Mutual, Industrial Risk Insurors, National Fire
        Prevention Association, the California Department of
        Industrial Relations (Occupational Safety and Health
        Division), the Federal Occupational Safety and Health
        Administration, or other relevant regulations and
        requirements.

     602  PROCEDURES:
          601.1     Operate the unit at the firing rate most
                    typical of normal operation.  If the unit
                    experiences significant load variations during
                    normal operations, operate the unit at its
                    average firing rate.

          601.2     At the firing rate established in Section
                601.1, record stack-gas temperatures, oxygen
                concentration, and CO concentration (for
                gaseous fuels) or smoke-spot number (for
                liquid fuels), and observe flame conditions
                after unit operation stabilizes at the
                selected firing rate.  If the excess oxygen in
                the stack-gas is at the lower range of typical
                minimum values, and if CO emissions are low
                and there is no smoke, the unit is probably
                operating at near optimum efficiency - at this
                particular firing rate.  However, complete the
                remaining portion of this procedure to
                determine whether still lower oxygen levels
                are practical.

          602.3     Increase combustion air flow until the stack-
                    gas oxygen levels increase by one or two
                    percent over the level measured in Section
                    602.2.  As in Section 602.2, record the stack-
                    gas temperature, CO concentration (for gaseous
                    fuels) or smoke-spot number (for liquid
                    fuels), and observe flame conditions for these
                    higher oxygen levels after unit operation
                    stabilizes.

          602.4     Decrease combustion air flow until the stack-
                    gas oxygen is at the level measured in Section
                    602.2.  From this level gradually reduce the
                    combustion air flow, in small increments. 
                    After each increment, record the stack-gas
                    temperature, oxygen concentration, CO
                    concentration (for gaseous fuels), and smoke-
                    spot number (for liquid fuels).  Also, observe
                    the flame and record any changes in its
                    condition.

          602.5     Continue to reduce combustion air flow
                    stepwise, until one of the following limits is
                    reached:
                    a.   Unacceptable flame conditions - such as
                         flame impingement on furnace walls or
                         burner parts, excessive flame carryover,
                         or flame instability;
                    b.   Stack-gas CO concentrations greater than
                         400 ppm;
                    c.   Smoking at stack;
                    d.   Equipment-related limitations - such as
                         low windbox/furnace pressure
                         differential, built-in air-flow limits,
                         etc.

          602.6     Develop an O2/CO curve (for gaseous fuels) or
                    O2/smoke curve (for liquid fuels) similar to
                    those shown in Figures 1 and 2 using the
                    excess oxygen and CO or smoke-spot number data
                    obtained at each combustion air flow setting.

          602.7     From the curves prepared in Section 602.6,
                    find the stack-gas oxygen levels where the CO
                    emissions or smoke-spot number equal the
                    following values:




Fuel              Measurement                Value


Gaseous          CO Emissions                400 PPM


#1 & #2 Oils     Smoke Spot Number           Number 1


#4 Oil           Smoke Spot Number           Number 2


#5 Oil           Smoke Spot Number           Number 3


Other Oils       Smoke Spot Number           Number 4


                    The above conditions are referred to as the CO
                    or smoke-spot thresholds, or as the minimum
                    excess oxygen levels.  Compare this minimum
                    value of excess oxygen to the expected value
                    provided by the combustion unit manufacturer. 
                    If the minimum level found is substantially
                    higher than the value provided by the
                    manufacturer, burner adjustments can probably
                    be made to improve fuel and air mix, thereby
                    allowing operations with less air.

          602.8     Add 0.5 to 2.0 percent to the minimum excess
                    oxygen level found in Section 602.7 and reset
                    burner controls to operate automatically at
                    this higher stack-gas oxygen level.  This
                    margin above the minimum oxygen level accounts
                    for fuel variations, variations in atmospheric
                    conditions, load changes, and nonrepeatability
                    or play in automatic controls.

          602.9     If the load of the combustion unit varies
                    significantly during normal operation, repeat
                    Sections 602.1-602.8 for the firing rates that
                    represent the upper and lower limits of the
                    range of the load.  Because control
                    adjustments at one firing rate may affect
                    conditions at other firing rates, it may not
                    be possible to establish the optimum excess
                    oxygen level at all firing rates.  If this is
                    the case, choose the burner control settings
                    that give the best performance over the range
                    of the firing rates.  If one firing rate
                    predominates, the setting should optimize the
                    conditions at the rate.

          602.10    Verify that the new settings can accommodate
                    the sudden load changes that may occur in
                    daily operation without adverse effects.  Do
                    this by increasing and decreasing load rapidly
                    while observing the flame and stack.  If any
                    of the conditions in Section 602.5 result,
                    reset the combustion controls to provide a
                    slightly higher level of excess oxygen at the
                    affected firing rates.  Next, verify these new
                    settings in a similar fashion.  Then make sure
                    that the final control settings are recorded
                    at steady-state operating conditions for
                    future reference.                                 
                    
                    
                                        Figure 1

                    Oxygen(O2)/CO Characteristic Curve

                               Source: KVB Inc.


                   Oxygen(O2)/Smoke Characteristic Curve
                               
                               Source: KVB Inc.