Apparently all those in Galt were notified about the arsenic levels in the drinking water being above acceptable EPA levels. The accepted limits are 10 parts per billion, and Galt's water levels of arsenic were from 11.5 to 14.3 parts per billion.
What does this mean to your pets?
Both dogs and cats have not been reported to suffer from long term arsenic exposure (perhaps because they do not live as long as humans). Also the "acceptable" levels recommended for our furry companions is 1 part per million or 1000 parts per billion so that the current elevation in Galt's water should not be a problem. Scientists have never been able to reproduce the skin lesions that effect humans with chronic exposure to arsenic.
Further of note: dog's clear out 45% of the arsenic they have ingested within about 2 hours, where it takes other pets and domestic animals up to two days.
So I think you can rest easy knowing that your pets should be ok drinking Galt's water. Of course, I don't care for the taste...