What is the CGP-approved method for pH analysis?

• A. Lab pH meter
• B. Colorimetric strips
• C. pH indicator tape
• D. Calibrated field meter

Answer: (D)

For CGP pH analysis, the on-site, properly calibrated field meter is the recommended method. This approach provides immediate, accurate readings at the point of sampling, which is essential because pH needs to be assessed within regulatory timeframes and under field conditions where sample integrity can change quickly. A calibrated field meter uses an electrode system and is calibrated with standard buffer solutions (and often includes temperature compensation) to ensure the reading reflects the actual stormwater pH at the time of sampling.

Relying on lab measurements would introduce delays and potential changes in pH during transport, and colorimetric strips or pH indicator tape generally offer less precision and reliability for regulatory purposes. In short, using a calibrated field meter aligns with the CGP requirement for timely, accurate on-site pH determination.