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Design and Specifications Included on the controller will be a single three-way switch (MANUAL-OFF- AUTOMATIC) for each step in the batch process. Each switch shall override the memory timer to provide direct manual control of the individual pump. Each switch shall also reset the PC to the START or STANDBY position by switching to the MANUAL position. Each switch shall have its own status light. Both the light and switch shall be mounted in,the enclo- sure door and have an identification nameplate identifying the switch function. The control panel shall have a digital settling time recorder. This recorder shall be mounted in the panel door and be visible from outside the panel. The recorder will automatically record, in minutes, the clarifier settling time after completion of the weiring cycle. The recorder will be operated by the solid-state memory controller PC and will be reset automatically upon completion of the settling cycle. 8. Flow Measuring. The treatment plant shall have a batch-counting device for calculating exact effluent flows. This device is a digital counter connected to the discharge pump cycle time in the PC which shall be programmable to read true batches discharged. The number of batches discharged times the fixed volume discharged from the chlorine contact chamber equals the plant total hydraulic flow. �7 F. PROCESS (Model 50EFO) I. Pretreatment and Reserve Capacity. The secondary treatment process shall be batch type with the aeration chamber designed for 16-hour detention time. Aeration reactor capacity shall allow a minimum of 33% of total daily flow as surge capacity from the standby level. 2. Aeration. Air for aeration and mixing is supplied to the aeration chambers by a regenerative- type blower sized to meet the plant's maximum-flow air requirements. Blower air shall be diffused through nonclog, air-seal diffusers as manufactured by Jet, Inc. Each diffuser shall direct air downward and shall screw-attach to a 1-inch Sch 80 PVC header. There shall not be more than 3 diffusers per header. Each header shall be connected to a 1-inch Sch 80 drop- pipe. Each drop-pipe shall have two unions connecting each section to facilitate removal. 3. Process Activation. When the mixed liquor (ML) rises in the aeration reactor to a pre- determined STANDBY LEVEL, a timed volume of ML (batch) is transferred to the clarifier. This process is activated by a circuit closing in the PC from a liquid-level control switch mounted at the STANDBY LEVEL. The location and timing of this switch (LCI) shall be set at plant startup. 4. Weiring. Skimming of the floatables occurs by weir overflow prior to the period of quiescent settling. The weir overflow returns the floatables directly to the aeration chamber. 5. Supernatant Transfer. At completion of the .settling period, a prescribed volume batch of supernatant liquor is transferred to the ozone contact chamber. This supernatant transfer shall be accomplished with no disturbance to settled sludge or floatables remaining in the clarifier. 6. Sludge Return. Upon completion of the supernatant transfer, the sludge and floatables remaining in the clarifier are returned to the primary aeration reactor for additional treatment i 12