While the plot was interesting and the matter is or could be an actual public health issue, I don't think the plot was meant for a CSI episode, because even when Ray said the water is the crime, the end of the big case, which is the water contamination, is way out of the hands of the CSI lab. They can help but they cannot solve it.
However, the content of the case was well developed, the evidence, the bodies, the hypothesis were believable enough to keep me interested the 43 minutes. I like the toughness of the new detective, but somehow I feel she does not have chemistry with the cast like other detectives like Vartan or Lockwood. Good to see Megan Ward again from the old series Dark Skies. I wish she did more TV.