INVESTIGATION OF THE CAUSES FOR LOW pH AT EAST BAY MUNICIPAL UTILITY DISTRICT'S WET WEATHER TREATMENT FACILITIES

摘要

During the 1997-1998 wet weather season, a new East Bay Municipal Utility Districtrn(EBMUD) wet weather treatment facility (San Antonio Creek WWTF) was put intornservice for the first time. During this first season the San Antonio Creek (SAC)rnWWTF experienced a low pH violation following the addition of sodium bisulfite (SBS)rnfor dechlorination. When similar dosages of SBS were applied to EBMUD's mainrnwastewater treatment plant's (MWWTP) primary effluent, the pH of the primaryrneffluent was not significantly depressed. It was determined that large amounts of rainrnwater diluted the buffering capacity of the sewage treated at the SAC WWTF, andrnresulted in the unusual pH depression observed following the addition of SBS at thernSAC WWTF. Methods are examined to remedy the pH problem.