On May 13, 2011, the Wisconsin Department of Natural Resources ("WDNR") reissued the Tier 1 and Tier 2 general permits for storm water discharges from industrial facilities. Because storm water is considered a point source discharge, these general permits were issued pursuant to WDNR's Wisconsin Pollutant Discharge Elimination System ("WPDES") permit program and Wis. Admin Code chapter NR 216.

WDNR regulates industrial storm water discharges on a three-tier basis:  Tier 1, Tier 2 and "no exposure" facilities. Tier 1 covers "heavy" industrial operations, Tier 2 covers more "light" industrial operations and "no exposure" facilities are those that have no discharge of contaminated storm water. WDNR also has several industry-specific storm water general permits, including those for auto dismantling, scrap recycling and nonmetallic mining. Chapter NR 216 contains a list of industrial facility types that must be covered under a storm water general permit. 

Tier 1 and Tier 2 storm water general permits were last issued in 2001, and expired in 2006. Since 2006, existing permittees have been lawfully operating pursuant to expired permits. Importantly, facilities already covered under an expired Tier 1 or Tier 2 permit will automatically be covered under the new permits - those facilities will receive written notification from WDNR of their coverage and a copy of the new permit. It will be most important for these already-covered facilities to carefully review the new permit to ensure that any new operational or recordkeeping requirements are addressed in the near-term. 

The new Tier 1 and Tier 2 permits include quite a bit of new language, intended to require permitted discharges to maintain applicable water quality standards for specific classified water bodies, including outstanding or exceptional waters; impaired water bodies, including those with EPA-approved Total Maximum Daily Loads in place; and fish and aquatic life waters.  These provisions require covered facilities to, among other things, identify the type of water way it discharges to, and check annually if any of its receiving waters have been added to the WDNR list of impaired waters. The new general permits also reference the recently updated NR 151 post-construction runoff management performance standards and have updated Storm Water Pollution Prevention Plan requirements.

WDNR and the U.S. Environmental Protection Agency technical guidance documents are available online to assist permittees with compliance; however, to date no new guidance documents have been developed specifically for the new general permits.  The WDNR fact sheet for the new general permits can be found here.