Green sediment in water

Three days after moving into my "new" (1950s) house and the brand new kitchen faucet clogged up with sandy sediment that is sort of a milky green color. I'm familiar with black sediment from iron pipes; is this green sediment natural with copper pipes? We're on utility water and have a gas water heater that's probably 5 to 8 years old. The house was unoccupied (except by realtors and our contractors) for at least a year before we moved in. Any guesses as to the source of this sediment and advice on what to do about it? I'm worried that all of the new appliances that we installed might get clogged up if this sediment continues to come.

What I would do is to flush out ALL the water lines and see if it does any good, I would not drink any of the water until it is all out. If flushing dosen't do any good I would have a commercial company sterilize the line.

I wouldn't go as far as spending money to "sterilize" the lines until a water test was done to determine if it is something harmful.

I would start by draining/flushing the water heater and all the lines. Houses that sit empty for long periods should always have this done when the system is brought back into operation.

Will do; I'll drain/flush everything out and see what happens. Ever seen this sort of greenish sediment before?

If part of the work that was done a year ago was sweating copper water lines there may have been soldering flux sitting in the pipes all that time. Flush the lines.