What is the minimum allowable pH for discharges to a POTW?

The minimum allowable pH for discharges to a Publicly Owned Treatment Works (POTW) is designed to protect the biological processes in wastewater treatment as well as to prevent damage to the infrastructure. The correct answer is that the minimum pH should be no lower than 5.5 at the point of discharge.

A pH level below 5.5 can be harmful to the microorganisms that are crucial for effective wastewater treatment, as acidic conditions can inhibit their metabolic activity and growth. Maintaining a pH that is too low can also lead to corrosion of pipes and equipment within the treatment facility, which can result in costly repairs and reduced efficiency in wastewater processing.

The other values listed as options indicate levels that may be too low for safe discharge into a POTW and do not align with the regulations set by environmental agencies. Understanding the implications of pH levels in wastewater management is essential for ensuring proper treatment and compliance with health and safety regulations.