We are considering purchasing a new home that has sat vacant for a little over a year. Upon turning all the faucets on and running the dishwasher, a strong sewer smell filled the house. The water also stinks. We didn't dare taste it. We think it may be from the water just standing in the pipes for a long time but would like some feedback on what else it could be.

Also would water sitting in pipes without being used cause any future problems?

I don't think the sewer smell came from the tap water.

My guess would be that since the house has been empty for so long, a lot of waste had dried and caked in the drain pipes.

When you turned the water on, and got all that dried crap wet, you brought it back to life.

I think that if you let all the pipes run for a while, pour some clorox down each drain in the house but don't use anything else with the clorox to avoid the danger of mixing some ammonia with the chlorine and flush well after letting it soak for a while you could eliminate this problem.

The only other possible issue would be if the home uses a well rather than a municipal water supply. That could change everything.

Good Luck!

The water system would need to be disinfected. I found a procedure for disinfecting a well, but not the house here. http://www.in.gov/idem/compliance/water/drinkingwater/factsheets/welldisinfection.pdf

The hot water heater would contain a large amount of water. Chlorine disapears from water naturally as it sits. There are some procedures online to disinfect a hot water heater.

The sewer gas smell is an easy one. If you would have been smart, you would have just added enough water to fill the traps The traps are the J pieces of pipe under the fixtures and the shower, etc. and in the toilet. This water prevents sewer gas from entering the home. By turning on one faucet, you wet the interior of the sewer pipe and released sewer gas through all of the drains in the house.

You also should check the roof vents to see if any animals nested in there.