Chemical Dosing Checks

Automated SCADA readings must be physically verified once per shift to ensure feed pumps are accurate.

Verification Procedure (Drawdown Test)

This test confirms the actual mL/min output of a chemical pump.

1. Isolate: Close the valve from the bulk tank to the calibration column.
2. Fill: Open the column fill valve to fill the calibration tube.
3. Run: Let the pump draw from the column for exactly 1 minute.
4. Measure: Record the mL dropped in the column.
5. Calculate: $$\text{Feed Rate (GPH)} = \frac{\text{mL/min} \times 0.0158}{1}$$

Tank Level Inspections

Check physical tank levels against SCADA.

• [ ] Sodium Hypochlorite: Verify day tank level matches ultrasonic sensor.
• [ ] PAC (Polymer): Visually inspect mixing energy in the day tank.
• [ ] Fluoride: Ensure saturator tank has visible crystals (undissolved salt) at the bottom.

!!! warning "Air Lock" If a pump is running but the flow meter reads zero, the pump head may be air-locked. Follow the Pump Priming SOP.