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Sampling Error?
November 18, 2007 | 09:32 AM

Fecal Coliform can easily turn up in a sample due to casual contact that contaminates the sample vessel. The timespan between sampling and lab analysis should also be of great concern when analyzing these results. Given the complexity of the sample's chain of custody and travel time to a lab, there's too much room for error.

Omnipresent pools of brackish water in that channel just makau of the highway provide ideal habitat for all the contaminants mentioned. Is the entire channel rife with such low spots? That would certainly explain the plume at the beginning of each flow. Perhaps we ought to evaluate whether the channel is settling (bad) or fill in the low spots with polymers designed for this purpose (expensive).

One final note: I live in Northern California most of the time, and even with our state's longtime focus on water quality, there are only a few labs qualified to perform this sort of analysis. I usually take samples in the wee hours and deliver them as the front doors of the lab are unlocked for the day. Sampling and delivering wastewater properly and promptly is crucial.


Tony the Process Wastewater Guy