Biological contamination and flooding: A plumbing question

The joys of home ownership! I have to replace some of the old galvanized steel plumbing in my house this weekend and have run into a problem. I’m replacing the cold water line from the water heater to the kitchen with 1/2" copper pipe.

The problem is this: where the current cold water line braches from the main line is directly above the furnace. To reach the “T” I would have to remove all the ductwork and tear down the furnace almost completely. Instead of doing this, I though I could cap off the current line about 10 feet from the “T” and branch a new line from the pipe that feeds the water heater.

OK, this I can do, but will having a 10’ length of stagnant water in this pipe have any deleterious effects? Could this pipe be a breeding ground for bacteria that will slowly poison my wife and I? Will the rate of corrosion in this pipe increase to the point where it will burst in the next year or two and flood my basement?

I do plan on replacing the pipe from the water heater to the main out at the street sometime in the next couple of years, but I would rather not take that project on now.

Thanks in advance for all the help…

You really need to check with the building and safety department in the city or country were the house is. If you want to sell the house the plumbing should be up to code. The lawyers can answer this better than I, but I think that there might be an implied warranty when you sell the house that you haven’t done anything illegal to it.

I am pulling permits to replace the current pipes so I will be going through an inspection. If this stop gap measure is not up to code, I am sure the city inspectors will inform me.

This is a temporary measure; the current pipe to my kitchen MUST be replaced. I will replace the rest of the system as soon as I can, hopefully this summer. If I leave a pipe connected to the system with 10 of still water for the next 6 month to a year or so, will there be any negative consequences regarding corrosion or bacterial growth?