EPA has released proposed guidance on post-construction compliance monitoring programs to verify the effectiveness of combined sewer overflow (CSO ) controls. The proposed guidance, according to EPA, is designed to assist municipal and state water officials in planning. It provides examples of planning documents that permittees should consider in preparing for post-construction monitoring including (i) quality assurance project plans, (ii) plans for assessing CSO controls, (iii) field sampling plans, and (iv) standard operating procedures. EPA will accept comments on the proposed guidance until September 30, 2011.