(a) All coagulation unit processes shall be provided with the following mandatory features for uninterrupted coagulant feed:

1. (1) Standby feeders,
2. (2) Adequate chemical stowage and conveyance facilities,
3. (3) Adequate reserve chemical supply, and
4. (4) Automatic dosage control.

(b) All coagulation unit processes shall be provided with one of the following reliability features:

1. (1) Alarm and multiple coagulation units capable of treating the entire flow with one unit not in operation;
2. (2) Alarm, short-term retention or disposal provisions, and standby replacement equipment;
3. (3) Alarm and long-term storage or disposal provisions;
4. (4) Automatically actuated long-term storage or disposal provisions, or
5. (5) Alarm and standby coagulation process.