I took samples of tapwater in order to examine concentrations of escherichia coli and enterococcus, in a rural area. I was told, by the analytical lab, to take samples in four sterilized vessels bought from pharmacy. The problem is that at the completion of the last vessel, its cap fell frοm my hand down to the soil and some grains of sand stack on the inner surface of the cap. As fast as I could, I picked it up and washed it off totally with the water of the sampling tap. After that I closed my last sampling vessel with it and this was the completion of the sampling. How great is the possibility my sample has a serious contamination of these twο biological pollutants after this incident?
Thanks and sorry for the long story and bad english