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In many cases, the maximum application rate is fixed by a regulatory agency. Some factors that must be considered in selection of the rate NOTES of application include: 1) efficiency of the secondary treatment proc- ess; 2) diurnal flow pattern and magnitude of any peak flow rate;3) filter cycle duration and backwash water production; 4) capital cost of equipment. Designed-in plant flow equalization allows filter design based on an equalized flow rate, which minimizes the number of problems that may result from periodic surge flows. With the unique batch design of the AquaClear secondary process, the daily flow patterns (as well as peak flow rates) are neutralized due to the hydraulic quality control of the mechanical process.Thus, a set schedule can be maintained for backwashing of the filter media. ELECTRONIC/ELECTRICAL CONTROL SYSTEM The solid-state control panel, provided by AquaClear, manages the operational functions of the treatment system from solid-state mem- ory.The memory is programmed at the factory and is retained in the program controller (PC) by either a battery backup or an EPROM. The memory consists of firmware located within the solid-state assembly. In addition to the PC are solid-state relays, circuit breakers, a dis- charge flow counter, and a settling time totalizer. Control cycles of individual pumps are preprogrammed within the timer. These cycles are based upon pumping times and are set dur- ing factory testing of the unit. Actual field operation times may vary; thus,field adjustment may be made when necessary. All pump cycles are protected from memory loss by standby battery, or by the EPROM, which retains the program memory during peri- ods of electrical interruptions. Protection of the control panel and PC from electrical spikes and surges is required where history of power fluctuations occur and/or where the primary power is supplied from onsite generators. Maximum demand is calculated at simultaneous operation of aera- tion,mixed-liquor transfer, and sludge return pumps. The electrical control system provides a separate alarm circuit pow- ered by a rechargeable batten;. Electrical connections and controls are installed in accordance with applicable local codes and ordi- nances. All the process pumps do not operate simultaneously in the auto- matic mode. In manual mode, the kw demand will vary proportionally to the cycle and the cycle duration the operator selects. 20