The Environmental Protection Commission will conduct public hearings on proposed amendments to Chapter 135, Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks. The amendments propose to revise the current Tier 2 software model (Tier 2 Version 2.51) based on observations during the first decade of use. The hearings will be held March 4, 5, and 6, 2008. http://www.legis.state.ia.us/Rules/Current/Bulletin/IAB080213.htm.