WASTEWATER By Rick Lallish
While operating an automatic composite sampling device, you notice elevated TSS or BOD in the effluent sample. What could be causing this problem?
A. Not enough samples in the 24-hour period
B. Refrigerator temperature set too low
C. Dirty labware/operator error
D. Sample tubing residue
Answer: D. Automatic samplers are outstanding and generally reliable devices if maintained properly. Dirty tubing can lead to elevated TSS or BOD readings in the effluent samples. The residue is biological growth and, if left unchecked, it will cause many problems. Periodic cleaning or changing of the rubber or plastic tubing is necessary. Other problems to look
