Air Quality Construction Permits for Cooling Towers

February 28, 2006

The DNR has a draft proposal to require air construction permits for cooling towers. There are exemptions in the draft proposal. DNR officials are encouraging facilities with cooling towers to view the draft policy at www.iowacleanair.com/input/input.html and provide any comments by 3/28/2006. Based upon comments, the DNR will make decisions on rulemaking and follow rulemaking procedures with additional comment periods.

The DNR is proposing the schedule below to maintain consistency in how all facilities are permitted. Currently, some facilities are requesting permits for cooling towers. If your facility has a cooling tower, we encourage you to read the five page draft proposal at the above web address and provide comments if warranted.

A few highlights of the draft DNR proposal include requiring all new industrial process cooling towers (IPCT) to obtain construction permits. The small unit exemption can be applied. Form EU 4 has been created specifically for cooling towers.

All existing IPCTs constructed after September 23, 1970 will require construction permits with a one year amnesty. In order to expedite permitting and limit the amount of work for facilities and DNR engineers, only a cover letter, Form FI, Form EU 4, and EC are required. Additional information may be required if the emissions from the cooling tower affect your facilities classification status.

All existing IPCTs constructed prior to September 23, 1970 are considered grandfathered. The 0.1 gr/scf PM standard is considered the applicable standard and used for potential to emit (PTE) if no other enforceable limits such as TDS limits, drift loss limits, etc. are used. For inventory purposes, actual emissions should be calculated using actual process data.

While the NESHAP for cooling towers promulgated on September 8, 1984 affects use of chromium based water treatment chemicals, section 112(f)(2) of the Clean Air Act directs EPA to assess the residual risk after NESHAP application and promulgate additional standards if warranted to provide an ample margin of safety for public health. EPA has reassessed information collected from water treatment chemical suppliers and determined HAP emissions of several compounds. EPA is also taking comments on their findings.

Additional details and ramifications on exemption "q" for cooling and ventilating equipment is provided on the draft proposal at www.iowacleanair.com/input/input.html as well as information for amending Title V insignificant rule and other information.

If you have questions after reading the draft proposal, please contact the hotline at 877-247-4692. Please provide comments on the draft DNR proposal to Dave Phelps at dave.phelps@dnr.iowa.gov.

• Draft Construction Permit Implementation Document for Cooling Towers