Tennessee Wastewater Operator Practice Exam

What is the approved method for measuring and reporting pH on the NPDES report according to federal regulations?

1. Colorimetric

2. Titrimetric

3. Electrometric

4. Fluorimetric

The correct answer is: Electrometric

The approved method for measuring and reporting pH on the NPDES report according to federal regulations is electrometric. This method involves using a pH electrode to measure the hydrogen ion concentration in a solution, providing a direct and precise measurement of pH levels. Electrometric measurement is favored because it offers high sensitivity and accuracy, making it suitable for regulatory compliance and environmental monitoring. In contrast, other methods such as colorimetric and titrimetric may be less accurate for pH determination. Colorimetric methods rely on color changes in pH indicators, which can be subjective and dependent on visual interpretation. Titrimetric approaches, while useful for determining the acidity or alkalinity of a solution, do not provide a direct measurement of pH at a given moment. Fluorimetric techniques are not commonly used for pH measurement as they are more suited for detecting specific compounds in solution rather than determining acidity or alkalinity. Thus, electrometric measurement stands out as the most suitable and reliable method for accurately measuring pH in compliance with NPDES reporting requirements.