Wisconsin Administrative Code
Department of Natural Resources
NR 400-499 - Environmental Protection - Air Pollution Control
Chapter NR 468 - Emission standards for hazardous air pollutants for miscellaneous processes
Section NR 468.30 - Industrial process cooling towers

(a) "Chromium-based water treatment chemicals" means any combination of chemical substances containing chromium used to treat water.

(b) "Construction" means the onsite fabrication, erection or installation of an industrial process cooling tower.

(c) "Cooling tower" means an open water recirculating device that uses fans or natural draft to draw or force air through the device to cool warm water by direct contact.

(d) "Existing industrial process cooling tower" means any industrial process cooling tower on which construction or reconstruction commenced on or before August 12, 1993.

(e) "Industrial process cooling tower" means any cooling tower that is used to remove heat that is produced as an input or output of a chemical or industrial process, as well as any cooling tower that cools a chemical or industrial process in combination with any heating, ventilation or air conditioning system.

Note: Cooling towers that only cool heating, ventilation and air conditioning systems and that are operated with hexavalent chromium-based water treatment chemicals are regulated by 40 CFR 749.68.

(f) "Initial startup" means the initiation of recirculation water flow within the cooling tower.

(g) "Major source" means any stationary source, or group of stationary sources, that is located on one or more contiguous or adjacent properties and is under common control of the same person or persons under common control, that emits or has the potential to emit, in the aggregate, 10 tons per year (tpy) or more of any hazardous air pollutant which has been listed pursuant to section 112 (b) of the act (42 USC 7412(b)) or 25 tpy or more of any combination of these hazardous air pollutants.

(h) "New industrial process cooling tower" means any industrial process cooling tower on which construction or reconstruction commenced after August 12, 1993.

(i) "Reconstruction" means the replacement of components of an industrial process cooling tower to such an extent that the fixed capital cost of the new components exceeds 50% of the fixed capital cost that would be required to construct a comparable new industrial process cooling tower.

(j) "Water treatment chemicals" means any combination of chemical substances used to treat water in cooling towers, including corrosion inhibitors, antiscalants, dispersants and any other chemical substances used to treat cooling tower water.

(a) No owner or operator of an existing industrial process cooling tower may use chromium-based water treatment chemicals in any industrial process cooling tower on or after March 8, 1996.

(b) No owner or operator of a new industrial process cooling tower may use chromium-based water treatment chemicals in any industrial process cooling tower on or after September 8, 1994, or on or after the date of the initial startup, whichever is later.

(a) Initial notification. Owners or operators of industrial process cooling towers that have an initial startup before September 8, 1994 shall submit, by registered mail, an initial notification to the department no later than October 1, 1996. Owners or operators of industrial process cooling towers that have an initial startup on or after September 8, 1994 shall submit, by registered mail, an initial notification no later than October 1, 1996, or 12 months after initial startup, whichever is later. The initial notification shall provide the following information and be signed by a responsible official who shall certify its accuracy:

(b) Notification of compliance status. Each owner or operator of an industrial process cooling tower shall submit to the department, by registered mail, a notification of compliance status on or before the 60th day following the date that the industrial process cooling tower is brought into compliance with sub. (3). The notification of compliance status shall:

(c) Prior notification under federal regulation. If the owner or operator of an industrial process cooling tower has submitted the notification required by par. (a) or (b) to the administrator under 40 CFR 63.405 prior to October 1, 1995, that notification shall be deemed to meet the applicable requirements of par. (a) or (b).

(d) Records retained at facility. Each owner or operator of an industrial process cooling tower shall retain copies of the notifications required under pars. (a) and (b) at the facility for a minimum of 5 years. The notifications shall be made available to department staff on request during normal business hours.