At the night of July 4, 2007, Waste water treatment plant faced with the waste water which had pH level lower to 5.1 and contained high COD about 7,378 mg/l.
There was no operator at that time and the systems were running.
This cause shock loads to the water treatment system.
Also, Anaerobic Bacteria were damaged so VFA. increased dramatically from 437 mg/l. to 1,654 mg/l. (follow data in the table) and Waste water treatment plant cannot treat the waste water since then. We suspect that the main cause is from the acid or beer flew into the waste water treatment system in a huge quantity.