Gray water is the water that comes out of your household appliances, showers, baths, etc. that is not seriously contaminated (but has been used).
Black water is water that has been infected with biological materials, primarily feces or urine.
Water Treatment in CT
Who supplies our water?
What does Aquarion do?
Ways to reduce:
Interactive Water Calculator: http://www.aquarion.com/CT/interactive-water-calculator