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6 .0 mgd of production capacity. On April 18, 2006, approximately 4.47 mgd of treatment capacity was available under typical conditions. With upward adjustments to feed pressures and train recoveries, a maximum treatment capacity of 5 .38 mgd could be achieved, still leaving a deficiency of 0.6 mgd. High Service Pumps The three existing high service pumps provide 6.9 mgd of pumping capacity with the largest out of service, approximately 1 . 6 mgd less than the treatment plant rated production capacity. High service pump systems are required by FDEP regulations, adopted August 28, 2003 , to have a capacity equal to the water system' s peak hourly demand unless the water system includes multiple water plants and/or remote storage facilities. Peak hourly demand is usually about 200 % of plant rated production capacity. Although FDEP regulations may allow the South RO Plant' s high service pumping capacity to be less than the peak hour requirement when combined with other connected treatment facilities and/or where remote storage is provided, the South Plant ' s high service pumping capacity should be increased to match that service area maximum-day demand, or the treatment production capacity. This will allow the South plant to place its daily production into the distribution system. The approach is to replace three of the existing 125 hp pumps/motors (2400 gpm capacity), with new 150 hp pumps, having a capacity of 3200 gpm each, and install variable frequency drives (VFD) on at least two of the three high service units. Due to age of the existing starters, replacement parts are no longer manufactured. Since regulations require that the largest pump be assumed out of service, the remaining 125 hp unit should be replaced to provide a firm capacity of at least 8 .57 mgd (6000 gpm) and provide pumps that have matched performance curves. This allows interchangeability of pumps in the control system and two VFD driven pumps to provide constant pressure performance. This will provide 9.27 mgd of connected pumping capacity with the largest out of service. If the third pump is not replaced, an increase in system operating pressure could not be obtained . Re-programming the high service pumping operation will also allow the facility to maintain constant pressure with variable system demands which is not currently available at this plant. Membrane Treatment System The existing membrane system is currently limited in capacity due to membrane damage from scaling, fouling, and intrusion of sand into the membranes. Several other mechanical features limit capacity such as leaking interstage valves, lack of first stage permeate control valves, and reduced feedwater pump capacity due to the age of the pumps. Replacement of the existing feedwater pump impellers is recommended since they were trimmed when first installed and also do not perform to original specifications due to wear. Replacement with full diameter impellers will increase pump flow/pressure capacity and allow an increase in capacity of the membrane system. Replacement of the impellers will not affect the motor sizes since they are sized for full diameter impellers . The approach to membrane replacement will include profiling of each pressure vessel to determine the extent of poor performance within the membrane system. Prior to purchasing membranes to replace all existing membranes, individual performance of all membranes will be evaluated and a replacement program will be developed. Once the extent of replacement is defined, a loading arrangement will be developed. Purchase of membranes for at least one-half of C:\MDM Files\South RO Plant Upgrades to Restore Capacity-rev9.doc Paget