WASTEWATER
By Rick Lallish
(This is a corrected version of the question that appeared in this space in last month’s edition.)
The MPN method for fecal coliform testing has become on the most common methods for testing. What is a disadvantage for MPN fecal coliform analysis?
A. Sample toxins are diluted
B. Samples cannot be analyzed by membrane filtration
C. Difficult to interpret, either by observation or gas emission
D. Results are not very accurate and have a high probability of false positives
Answer: D. It is important for operators to understand the many types of laboratory procedures and analysis so that they can properly operate a wastewater treatment facility.
