New Well - Green Hot Water

My home previously had an interior well (38') in the basement and I recently had a new, exterior well drilled that met our local code requirements.

The well driller went down to 60', got static water level at 31' and the water company took the 1/2 HP pump from the old inside well and dropped it in at 45' in the new exterior well. The bacteria test came back negative. I already tested for PH which is 7.5 but the alkalinity was off the chart. The rest were normal (nitrate, copper, iron, etc.) The water at the test faucet is clear, and the softened cold water lines in the house are pretty clear, but the hot water coming through the softener and indirect hot water heater is green. Serious green, like St Paddy's Day green! The only filter in the system is the water softener and I never had green water prior to the cutover to the new well.

The new water line into the house is polyethylene pipe cutting over to copper just inside the house. All the other water lines are copper. What could be causing only the hot water to turn green with this new well?

I couldn't help but to notice you wrote "hot water coming through the softener". I don't know of any softener that recommends HOT water go through it.

No, sorry, I meant that the water coming out of the indirect has already passed through the softener. I only have two lines that don't run through the softener - cold water line to the kitchen sink and outside hose bib.

Green means dissolved copper, and it will likely dissipate after the new installation gets coated internally with some deposits.

Is it a tank water heater?

food for thought: http://www.epa.gov/nrmrl/wswrd/cr/corr_res_copper_ai2.html

You might want to take a chemical sample on the hot side. Hot water makes corrosive water more aggressive. There are many things that can effect corrosion such as how soft or hard the water is, concentrations of carbon dioxide and dissolved oxygen, alkalinity, dissimilar metals, improper grounding etc. If the water is corrosive it will not build up a protective scale on the inside of the pipe.