SACAQMD RULE 446 STORAGE OF PETROLEUM PRODUCTS          
LAST REVISED 11/16/93          

          SACRAMENTO METROPOLITAN AQMD                RULES AND REGULATIONS
                              RULE 446 STORAGE OF PETROLEUM PRODUCTS
                                          Adopted 6-1-74
                      (Amended 6-1-74, 8-3-77, 11-29-83, 12-4-90, 11-16-93)



                                              INDEX

          100 GENERAL
              101  PURPOSE
              110  EXEMPTIONS

          200 DEFINITIONS
              201  EFFICIENCY
              202  GAS TIGHT
              203  ORGANIC LIQUIDS

          300 STANDARDS
              301  CONTAINERS LARGER THAN 150,000 LITERS (40,000 GALLONS)
              311  FLOATING ROOF
              312  INTERNAL FLOATING ROOF
              313  VAPOR RECOVERY SYSTEM
              314  CLOSURE DEVICE REQUIREMENTS
              315  METALLIC SHOE SEAL REQUIREMENTS
              316  WELDED TANKS WITH METALLIC SHOES SEALS
              317  RESILIENT TOROID SEAL REQUIREMENTS

          400 ADMINISTRATIVE REQUIREMENTS
              401  INSPECTION, SELECTED LOCATIONS
              402  INSPECTION, FULL CIRCUMFERENCE

          500 MONITORING AND RECORDS
              501  RECORDS
              502  TESTING PROCEDURE
          
          100 GENERAL

              101  PURPOSE:   To  limit  emissions  from  storage tanks for
                   organic liquids with a vapor pressure greater  than  1.5
                   psia (10.3 kPa) under actual storage conditions.

              110  EXEMPTIONS: This rule shall not apply to emissions from:
                   110.1   Stationary  storage  tanks  having a capacity of
                           less  than  or equal to 150,000  liters  (40,000
                           gallons).
                   110.2   The provisions of Section 301 shall not apply to
                           tanks involved in periodic scheduled maintenance
                           or  replacement   operations   of   primary   or
                           secondary  seals  that  cause  the  emissions of
                           volatile   organic   compounds.   Such  periodic
                           scheduled maintenance must be done in accordance
                           with a plan as defined  in Section 403 which has
                           prior  written  approval of  the  Air  Pollution
                           Control Officer.  Scheduled periodic maintenance
                           operations shall  not  be  conducted from May 15
                           through October 15.

          200 DEFINITIONS

              201  EFFICIENCY:  A  comparison  of controlled  emissions  to
                   those emissions which would occur  from  a fixed or cone
                   roof  tank in the same product service without  a  vapor
                   loss  control   system.   Baseline  emissions  shall  be
                   calculated using  the  criteria  in  American  Petroleum
                   Institute Bulletin 2518.

              202  GAS  TIGHT:  A concentration of total organic compounds,
                   measured  one  (1)  cm  from  any source, which does not
                   exceed   10,000   ppm  (expressed  as   methane)   above
                   background,  as determined  by  a  method  specified  in
                   Section 502.3.

              203  ORGANIC LIQUID:   Compounds and mixtures of compounds of
                   carbon which are liquid under actual storage conditions.

          300 STANDARDS

              301  CONTAINERS LARGER THAN  150,000 LITERS (40,000 GALLONS):
                   A  person  shall  not  store   organic   liquid  in  any
                   stationary container of more than 150,000 liters (40,000
                   gallons) capacity, unless such container is:
                   301.1   a  pressure  tank maintaining working  pressures
                           sufficient at all times to prevent organic vapor
                           or gas loss to the atmosphere, or
                   301.2   designed and equipped with one of the vapor loss
                           control devices  specified in Sections 311, 312,
                           or 313.

              311  FLOATING ROOF: The vapor loss  control  device  may be a
                   floating  roof equipped with a closure device consisting
                   of  a  floating  pan-type  roof  or  a  pontoon-type  or
                   double-deck  cover.  All floating roofs must rest on the
                   surface of the liquid contents.
                   311.1   The closure  device  shall consist of two seals,
                           one  above the other; the  one  below  shall  be
                           referred  to  as  the primary seal, and  the one
                           above  shall be referred  to  as  the  secondary
                           seal.  The  closure device shall comply with the
                           requirements  specified  in Sections 314 through
                           317.
                   311.2   A floating roof shall not be used if the organic
                           liquid stored  has a true  vapor  pressure of 11
                           psia (75.9 kPa) or greater under actual  storage
                           conditions   as   determined   by   the  methods
                           specified in Section 502.4.

              312  INTERNAL  FLOATING  ROOF: The vapor loss control  device
                   may  be  a  fixed roof with  an  internal  floating-type
                   cover.
                   312.1   A    fixed     roof     container     with    an
                           internal-floating-type cover shall not  be  used
                           if  the  organic  liquid stored has a true vapor
                           pressure of 11 psia  (75.9 kPa) or greater under
                           actual storage conditions  as  determined by the
                           methods specified in Section 502.4.

              313  VAPOR  RECOVERY  SYSTEM:  The vapor loss control  device
                   may be a vapor recovery system capable of collecting and
                   processing all organic  vapors and gases and which meets
                   the following requirements:
                   313.1   The system shall  have  a recovery efficiency of
                           at least 95% by weight as  determined by methods
                           specified in Section 502.
                   313.2   Any tank gauging or sampling  device  on  a tank
                           vented  to  the  vapor  recovery system shall be
                           equipped with a gas-tight  cover  which shall be
                           closed  at all times, except during  gauging  or
                           sampling.
                   313.3   All pressure-vacuum  valves shall be constructed
                           and maintained in a gas-tight condition when the
                           valve is seated.

              314  CLOSURE DEVICE REQUIREMENTS: The  closure  device on any
                   floating  roof  container  subject to Section 311  shall
                   meet the following requirements:
                   314.1   Any secondary seal shall extend from the roof to
                           the tank shell and shall  not be attached to the
                           primary seal.
                           a.  For secondary seals installed after December
                               4, 1991 no gap between  the  tank  shell and
                               the seal shall exceed:
                               1.  0.15 cm (0.06 in)
                               2.  0.05  cm  (0.02  in)  for  a  cumulative
                                   length    greater   than   5%   of   the
                                   circumference of the tank.
                   314.2   All openings in the roof, except pressure-vacuum
                           valves, sampling wells,  and gauging wells shall
                           meet the following  requirements:
                           a.  The opening shall provide a projection below
                               the liquid surface to  prevent  belching  of
                               liquid  and  to  prevent entrained or formed
                               organic vapor from  escaping from the liquid
                               contents of the tanks.
                           b.  The opening shall be  equipped with a cover,
                               seal or lid, which shall  be  closed  at all
                               times with no visible gaps, except when  the
                               opening is in use.
                   314.3   Pressure-vacuum  valves  shall  be set to within
                           10% of the maximum allowable working pressure of
                           the roof.
                   314.4   Solid sampling and gauging wells  shall meet the
                           following  requirements:
                           a.  The  well  shall provide a projection  below
                               the liquid surface.
                           b.  The well shall  be  equipped  with  a cover,
                               seal  or  lid, which shall be closed at  all
                               times with  no visible gaps, except when the
                               well is in use.
                   314.5   Slotted sampling  and  gauging  wells shall meet
                           the following  requirements:
                           a.  The  well  shall provide a projection  below
                               the liquid surface.
                           b.  The well shall  be  equipped with one of the
                               following closure devices  which shall be in
                               place at all times except when  the  well is
                               in use:
                               1.  An  internal  float designed to minimize
                                   the gap between  the float and the well,
                                   provided that the  gap  shall in no case
                                   exceed 1.3 cm (1/2 in).
                               2.  A  capped  internal sleeve  designed  to
                                   minimize the  gap between the sleeve and
                                   the well, provided that the gap shall in
                                   no case exceed 1.3 cm (1/2 in).
                               3.  An internal sleeve  with no visible gaps
                                   between the sleeve and  the  well  and a
                                   cover,  seal or lid on the well with  no
                                   visible gaps.
                   314.6   Any roof drain shall  be provided with a slotted
                           membrane  fabric  cover,   or  equivalent,  that
                           covers at least nine-tenths  of  the area of the
                           opening.
                   314.7   The  gap between sampling wells, gauging  wells,
                           and similar fixed projections through a floating
                           roof,  such  as  anti-rotational  pipes, and the
                           roof  shall  be  added  to the gaps measured  to
                           determine compliance of the  secondary  seal and
                           in no case shall exceed 1.3 cm (1/2 in).

              315  METALLIC  SHOE  SEAL  REQUIREMENTS:   For  any container
                   which  uses a metallic shoe seal to comply with  Section
                   311, the seal shall meet the  following requirements:
                   315.1   There  shall  be  no  holes,  tears, or openings
                           which  allow  the  emission  of  organic  vapors
                           through the secondary seal. There  shall  be  no
                           holes,  tears,  or  openings in the primary seal
                           envelope surrounding  the  annular  vapor  space
                           enclosed   by   the  roof  edge,  stored  liquid
                           surface, shoe, and seal fabric.
                   315.2   Metallic-shoe-type  seals  installed on or after
                           September 1, 1978, shall be  installed  so  that
                           one  end  of  the  shoe extends  into the stored
                           liquid  and  the other  end  extends  a  minimum
                           vertical distance  of  61  cm  (24 in) above the
                           stored liquid surface.
                   315.3   The geometry of the shoe shall be  such that the
                           gap  between  the shoe and the tank shell  shall
                           not exceed twice  the  seal  gap requirements of
                           Section 316 for a vertical length  greater  than
                           45.7 cm (18 in).

              316  WELDED  TANKS  WITH  METALLIC SHOE SEALS: For any welded
                   tank shell which uses  a  metallic  shoe  seal to comply
                   with  Section  311,  the  seal  shall meet the following
                   requirements:
                   316.1   No gap between the tank shell  and  the  primary
                           seal shall exceed
                           a.  3.8 cm (1-1/2 in).
                           b.  1.3  cm  (1/2  in)  for  a cumulative length
                               greater than 10% of the circumference of the
                               tank.
                           c.  0.32 cm (1/8 in) for a continuous  length of
                               more  than  10% of the circumference of  the
                               tank.
                           d.  0.32 cm (1/8  in)  for  a  cumulative length
                               greater than 40% of the circumference of the
                               tank.
                   316.2   No gap between the tank shell and  the secondary
                           seal shall exceed
                           a.  1.3 cm (1/2 in)
                           b.  0.32  cm  (1/8  in) for a cumulative  length
                               greater than 5% of  the circumference of the
                               tank.
                   316.3   The secondary seal shall allow easy insertion of
                           probes up to 3.8 cm (1-1/2 in) in width in order
                           to measure gaps in the primary seal.

              317  RESILIENT TOROID SEAL REQUIREMENTS:  For  any  container
                   which  uses  a  resilient  toroid  seal  to  comply with
                   Section   311,   the   seal  shall  meet  the  following
                   requirements:
                   317.1   There  shall be no  holes,  tears,  or  openings
                           which  allow  the  emission  of  organic  vapors
                           through  the  secondary seal.  There shall be no
                           holes, tears, or  openings  in  the primary seal
                           envelope  surrounding  the annular  vapor  space
                           enclosed  by  the  roof edge,  seal  fabric  and
                           primary seal.
                   317.2   For primary seals no  gap between the tank shell
                           and the seal shall exceed:
                           a.  1.3 cm (1/2 in)
                           b.  0.3  cm  (1/8 in) for  a  cumulative  length
                               greater than  5% of the circumference of the
                               tank.
                   317.3   For secondary seals  no  gap  between  the  tank
                           shell and the secondary seal shall exceed:
                           a.  1.3 cm (1/2 in)
                           b.  0.3  cm  (1/8  in)  for  a cumulative length
                               greater than 5% of the circumference  of the
                               tank.
                   317.4   The secondary seal shall allow easy insertion of
                           probes  up  to 1.3 cm (1/2 in) in width in order
                           to measure gaps in the primary seal.

          400 ADMINISTRATIVE REQUIREMENTS

              401  INSPECTION,  SELECTED   LOCATIONS:   The   primary  seal
                   envelope shall be available for unobstructed  inspection
                   by  the  APCO  on  an  annual  basis  at  four locations
                   selected along its circumference at random  by the APCO.
                   If the APCO detects one or more violations as  a  result
                   of  any  such  inspection,  the  APCO  may  require such
                   further unobstructed inspection of the primary  seal  as
                   may be necessary to determine the seal condition for its
                   entire circumference.

              402  INSPECTION, FULL CIRCUMFERENCE: For tanks with secondary
                   seals  installed  after  September  1, 1978, the primary
                   seal envelope shall be made available  for inspection by
                   the  APCO  for  its  full  length  every  5 years  after
                   September 1, 1977, except that if the secondary  seal is
                   voluntarily  removed  by  the  owner  or  operator prior
                   thereto, it shall be made available for such  inspection
                   at  that  time.  The  owner  or  operator  shall provide
                   notification  to  the  APCO no less than 7 working  days
                   prior to voluntary removal of the secondary seal.

              403  MAINTENANCE PLAN:  Maintenance  plans shall be submitted
                   to  the Air Pollution Control Officer  at  least  thirty
                   days  prior  to anticipated maintenance.  The plan shall
                   state  the amount  and  type  of  emission  anticipated,
                   method of calculating emissions, and the reason that the
                   work  is   necessary,   including   the  effect  of  not
                   performing the maintenance.

          500 MONITORING AND RECORDS

              501  RECORDS: A person storing organic liquids  shall keep an
                   accurate  record  of  liquids  stored,  the  true  vapor
                   pressure  ranges, and the actual storage temperature  of
                   such liquids.

              502  TESTING PROCEDURE:  A  result by any of the below listed
                   test  methods  which  shows   non-compliance   with  any
                   provision  of  the rule shall constitute a violation  of
                   the rule.
                   502.1   CONTROL  DEVICE: Control efficiency and emission
                           rates of control  devices shall be determined by
                           EPA Method 25 or ARB Method 422.
                   502.2   COLLECTION  EFFICIENCY:   Collection  efficiency
                           shall   be   determined    using   Environmental
                           Protection  Agency  Guidelines   for  Developing
                           Capture   Efficiency   Protocols,   55   Federal
                           Register 26865, June 29, 1990.
                   502.3   LEAK DETECTION: EPA Reference Method 21.
                   502.4   VAPOR  PRESSURE:  Vapor pressure may be obtained
                           from  standard  reference   texts   or   may  be
                           determined by ASTM D-2879-83 or ASTM D-323-82.