Just following up on this post from a couple of months back. Just after my last post on this in April, I contacted the local Water District and spoke to their manager. I also sent him a photo of what I found on our inlet screen. He says that properties that are seasonal like in RV parks and in areas where there are recreational summer cottages, the chlorine level in the water dissipates and drops to nothing because the water stagnates and does not move (or very little) over the winter months. This gives any organsisms that may be present in water time to grow. Upon seeing the photo, he says in the water 'biz, they call it slime... It's a biomass that is not toxic and can happen anywhere where water sits in piping for long periods without moving.
The manager said that he has spoken to our CG a number of times in the past and advised them that they should flush all of their lines at the beginning of each season. Judging by the level of maintenance they do around the property in general, I'm not so sure they flush the lines when they should. He said he would go to the cg and advise them (again) that they need to flush their lines.
Interestingly, when we returned to the cg a couple of weeks later, we found this sign a few hundred feet away from the cg on the road leading into it. The public supply line may have had biomass buildup in it as well.
All I know is, even if it's non-toxic, just the thought of ingesting that stuff makes me sick. We will never use a cg's water supply again without filtration. We now have a 4 stage filter setup ending with micro-filtration (used in in bulk water dispensers in stores).
