GREAT BASIN UNIFIED AIR POLLUTION CONTROL DISTRICT
RULE 427 - CHROMATE TREATED COOLING TOWERS
- Purpose. To comply with the Air Resources Board's Hexavalent Chromium Airborne Toxic Control Measure for Chromate
Treated Cooling Towers, as required by California Health and Safety Code Section 39666.
- Definitions. For the purposes of this rule, the following definitions shall apply:
- "Chromium": Hexavalent chromium.
- "Cooling tower": A device which evaporates circulating water to remove heat from a process, building,
or refrigerator and transfers the heat to the ambient air.
- "Water treatment chemicals": Any combination of chemicals which are added to cooling tower water
including, but not limited to, corrosion inhibitors, antiscalants, tracers, dispersants and biocides.
- "Wooden cooling tower": A cooling tower containing wood components which are exposed to the circulating
- Requirements: The requirements of this rule shall apply to any cooling tower in which the circulating water
is exposed to the ambient air. A person shall not operate any cooling tower unless the following requirements are
- No chromium containing compounds shall be added to the cooling tower circulating water;
- The concentration of chromium in the cooling tower circulating water shall not exceed:
- 0.15 milligrams per liter (mg/l) in any non-wooden cooling tower, effective June 12, 1991;
- 8.0 mg/l, effective June 12, 1991, and 0.15 mg/l, effective December 12, 1991, in any wooden cooling tower.
Between June 12, 1991 and December 12, 1991, the measured concentrations must decrease each month.
- Compliance shall be determined by testing the concentration of chromium in the circulating water every six
months in non-wooden cooling towers and monthly in wooden cooling towers. Testing may be discontinued if two required
consecutive tests show chromium concentrations less than 0.15 mg/l. The Air Pollution Control District (APCD) may
require testing of the circulating water at any time, to confirm that the water does not contain chromium in excess
of 0.15 mg/l;
- A compliance plan, as defined in Section D, shall be submitted to the APCD by March 12, 1991 or 90 days prior
to placing a new cooling tower in operation.
- Compliance Plan: Owners or operators of cooling towers located at separate stationary sources shall submit
a separate compliance plan for each stationary source. A compliance plan shall be accompanied by the fee specified
and shall contain the following:
- The name, address, and phone number of the cooling tower operator and owner;
- The cooling tower location including the address and the site specific location;
- The cooling tower specifications including type of construction and materials of construction.
- The trade and chemical names of the water treatment additives currently in use, the Material Safety Data Sheets
for these additives, and the name and address of the manufacturer and supplier;
- The date when the addition of chromium containing compounds to the circulating water ceased, or will cease.
- If chromium containing compounds have not been added to the circulating water in a cooling tower since June
12, 1990, or have never been added, the APCD may waive the requirements of subsections C.3 and C.4. A person seeking
an exemption pursuant to this subsection shall submit to the APCD written certification, signed by a company officer,
stating that chromium containing compounds have not been added to the cooling tower circulating water since June
12, 1990, or have never been added. In addition, the written certification shall contain the information specified
in subsections D.1, D.2, and D.4. The APCD may require the testing of the circulating water at any time, to confirm
that the circulating water does not contain chromium in excess of 0.15 mg/l.
- Any cooling tower in which the circulating water is completely contained and is not exposed to the ambient
air is exempt from the provisions of this rule.
- Recordkeeping Requirements: Any person subject to the requirements of subsection C.3 shall maintain records
of all circulating water tests performed pursuant to subsection C.3. The records shall be retained for at least
two years and shall be made available to the APCD upon request.
- Reporting Requirements: By January 12, 1992 and annually thereafter, any person subject to the requirements
of subsection C.3 shall submit to the APCD the results of all circulating water tests performed pursuant to subsection
C.3. In addition, the submitted test results shall include the date the test was performed, and the name and address
of the laboratory performing the test.
- Test Methods: Compliance with the chromium concentration limits in sub section C.2, shall be determined by
American Public Health Association Method 312B.
- Compliance Schedule: Any person subject to the provisions of Section C shall meet the following compliance
- Achieve compliance with the requirements of subsection C.1 by April 12, 1991;
- Begin testing pursuant to the requirements of subsection C.3, by July 12, 1991.