Blending and post-treatment protocols for SDWA compliance - Hollywood (FL) water plant

摘要

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 consumptive use of the Biscayne Aquifer as raw supply to the City's 37.5 mgd lime softening plant. The three-phase plan which was adopted involves staged replacement of obsolescent softeners and filters with RO membranes, using both the Biscayne and the deeper, better contained, but brackish 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 Aquifer withdrawal at or below current permitted amounts, with eventual curtailment; and residuals and concentrate disposal effected in an environmentally acceptable manner. These operating constraints, plus the unusual requirements for blending control make this project an important and instructive prototype for our changing water utility industry.