SACAQMD RULE 481 COOLING TOWERS          
LAST REVISED 10/29/91          

          SACRAMENTO METROPOLITAN AQMD                RULES AND REGULATIONS
                                     RULE 481 COOLING TOWERS
                                         Adopted 10-29-91

                                              INDEX

          100 GENERAL
              101  PURPOSE
              110  EXEMPTION

          200 DEFINITIONS
              201  COOLING TOWER
              202  HEXAVALENT CHROMIUM CONTAINING WATER TREATMENT CHEMICALS
              203  WATER TREATMENT CHEMICALS

          300 STANDARDS
              301  HEXAVALENT CHROMIUM REMOVAL
              302  CIRCULATING WATER CONCENTRATION - WOODEN COOLING TOWERS
              303  CIRCULATING  WATER  CONCENTRATION  -  NON-WOODEN COOLING
                   TOWERS

          400 ADMINISTRATIVE REQUIREMENTS
              401  COMPLIANCE SCHEDULE

          500 MONITORING AND RECORDS
              501  TESTING PROCEDURE
              502  MONITORING-GENERAL
              503  MONITORING-WOODEN COOLING TOWERS
              504  MONITORING-NON-WOODEN COOLING TOWERS
              505  RECORD KEEPING

              101  PURPOSE: To limit hexavalent chromium emissions  to  the
                   atmosphere  from  cooling towers by eliminating chromium
                   based circulating water treatment programs.

              110  EXEMPTION: The requirements  of  Sections  503  and 504,
                   shall   not  apply  if  hexavalent  chromium  containing
                   compounds  have  not been added to the circulating water
                   in a cooling tower  since  August 1, 1990, or have never
                   been added, and documentation,  required in Section 401,
                   has  been  approved  in  writing  by the  Air  Pollution
                   Control Officer.

          200 DEFINITIONS

              201  COOLING TOWER: Any open water recirculation  device that
                   uses  fans  or  natural  draft  to draw or force air  to
                   contact  and  cool  water by evaporation,  except  those
                   devices in use in single family residences.

              202  HEXAVALENT    CHROMIUM-CONTAINING     WATER    TREATMENT
                   CHEMICALS:  Water  treatment  additives  which   contain
                   hexavalent  chromium (Chrome VI) alone or in combination
                   with other water treatment chemicals.

              203  WATER TREATMENT  CHEMICALS: Any combination of chemicals
                   used  to  treat  circulating  water  including  tracers,
                   corrosion  inhibitors,   antiscalants,  dispersants  and
                   biocides.

          300 STANDARDS

              301  HEXAVALENT CHROMIUM REMOVAL: Effective April 29, 1992, a
                   person shall not supply, sell,  solicit,  offer for sale
                   or  add  hexavalent chromium-containing water  treatment
                   chemicals to or for the circulating water of any cooling
                   tower.

              302  CIRCULATING WATER CONCENTRATION - WOODEN COOLING TOWERS:
                   A person shall not operate a wooden cooling tower unless
                   the following requirements are met:
                   302.1   By  April  29,  1992:  The  hexavalent  chromium
                           concentration in the circulating water does  not
                           exceed 8 milligrams per liter.
                   302.2   For   hexavalent   chromium   concentration   in
                           circulating  water  greater than 0.15 milligrams
                           per  liter,  the  concentration   of  hexavalent
                           chromium concentration in the circulating  water
                           decreases  each  month  from  April  29, 1992 to
                           October 29, 1992.
                   302.3   By  October  29,  1992:  The hexavalent chromium
                           concentration in the circulating  water does not
                           exceed 0.15 milligrams per liter.

              303  CIRCULATING  WATER  CONCENTRATION  - NON-WOODEN  COOLING
                   TOWERS:  Effective April 29, 1992, a  person  shall  not
                   operate a non-wooden cooling tower unless the hexavalent
                   chromium concentration in the circulating water does not
                   exceed 0.15 milligrams per liter.

          400 ADMINISTRATIVE REQUIREMENTS

              401  COMPLIANCE  SCHEDULE: Any owner or operator of a cooling
                   tower shall submit  a  written  compliance  plan  to the
                   District, by January 29, 1992. Any owner or operator  of
                   a cooling tower constructed after January 29, 1992 shall
                   submit  a  written  compliance  plan  to the District at
                   least  90  days  before  the  tower is constructed.  The
                   compliance plan shall contain the following:
                   401.1   Name, address and telephone numbers of the owner
                           and operator.
                   401.2   Cooling tower location including the address and
                           specific location of each cooling tower.
                   401.3   The   materials  used  in  the   cooling   tower
                           construction.
                   401.4   The  trade  and  chemical  names  of  the  water
                           treatment  additives  proposed  to  be  used  or
                           currently  in  use,  and the name and address of
                           the manufacturer and supplier.
                   401.5   Date  when hexavalent chromium-containing  water
                           treatment chemicals were last added.

          500 MONITORING AND RECORDS:

              501  TESTING PROCEDURE: Samples of circulating water shall be
                   analyzed for hexavalent  chromium  as  prescribed by the
                   American  Public  Health  Method  312B or an  equivalent
                   method. Such equivalent method must  be  approved by the
                   Air  Pollution  Control  Officer.  If used to  determine
                   compliance, such equivalent method must provide the same
                   results as the test method it is replacing.

              502  MONITORING-GENERAL:  The Air Pollution  Control  Officer
                   may either require the testing of the circulating  water
                   at  any time, or sample the water and submit for testing
                   at the  owner  or  operators  expense,  to determine the
                   concentration of hexavalent chromium.
                   502.1   Hexavalent chromium concentration  test  results
                           including the date of the test, and the name and
                           address  of  the laboratory performing the test,
                           must be submitted  to  the Air Pollution Control
                           Officer within 30 days of the date collected.

              503  MONITORING - WOODEN COOLING TOWERS:
                   a.      From  April  29, 1992 until  October  29,  1992:
                           Compliance with  Section 302.1 shall be verified
                           by  testing the water  utilizing  the  procedure
                           specified  in  Section  501  at least once every
                           month   to   determine   the  concentration   of
                           hexavalent chromium.
                   b.      By  October 29, 1992:  Compliance  with  Section
                           302.2 shall be verified by testing utilizing the
                           procedure specified in Section 501.

              504  MONITORING-NON-WOODEN  COOLING  TOWERS:  Compliance with
                   Section 303 shall be verified by  testing  utilizing the
                   procedure specified in Section 501.

              505  RECORD KEEPING: Any owner or operator of a cooling tower
                   subject to this rule shall maintain records  of  testing
                   for  two years and make the records available for review
                   by the Air Pollution Control Officer upon request.