1. Environmental Protection Agency, Process Design Manual for Upgrading Existing Wastewater Treatment Plants, EPA 625/1–71–004a, pp. 5–13 (October 1974).
2. , and , “Meet New NPDES Permit Limits,” Hydrocarbon Processing, pp. 67–72 (August 1991).
3. Metcalf and Eddy, Inc., Wastewater Engineering: Treatment, Disposal, Reuse, McGraw-Hill, second edition, pp. 480–485 (1979).
4. and , “Optimize the Effluent System—Part 1: Activated Sludge Process,” Hydrocarbon Processing, pp. 105–112 (March 1976).
5. , and , “Reduce Oil and Grease Content in Wastewater,” Hydrocarbon Processing, pp. 102–110 (June 1993).