BLENDING AND POSTTREATMENT PROTOCOLS FOR SDWA COMPLIANCE - HOLLYWOOD (FL) WATER-PLANT

In 1988 the City of Hollywood, Florida prepared a 10-year water supply and treatment plan as a condition for renewal of its permit for consu mptive use of the Biscayne Aquifer as raw supply to the City's 37.5 mg d lime softening plant. The three-phase plan which was adopted involve s staged replacement of obsolescent softeners and filters with RO memb ranes, using both the Biscayne and the deeper, better contained, but b rackish Floridan Aquifer as raw water supplies. Operating and blending protocols had to be developed which would ensure at all times during and after project implementation: Satisfaction of public water demand; water quality in compliance, present and future; Eastern Biscayne Aqu ifer withdrawal at or below current permitted amounts, with eventual c urtailment; and residuals and concentrate disposal effected in an envi ronmentally acceptable manner. These operating constraints, plus the u nusual requirements for blending control make this project an importan t and instructive prototype for our changing water utility industry.