On January 5, 1976, the Illinois Environmental Protection Agency proposed an amendment to the Water Pollution Control Regulations (Chapter 3) which: (1) deletes the general water quality standard for phosphorus of 0.05 mg/l, and (2) adds a new effluent standard for phosphorus (1.0 mg/l) for discharges affecting lakes and reservoirs of 20 acres or larger. In addition, the proposed amendment would change certain portions of the effluent standards to make them compatible with the National Pollution Discharge Elimination System (NPDES). These latter changes are largely administrative, with no significant environmental or economic consequences. The proposed regulatory action was designated as PCB R76-1 (Appendix A), and was published in the 'Environmental Register' no. 118, January 27, 1976.