A large percentage of the homes in America get their water from an auxiliary source of water. The most common auxiliary water source is a private well. Private wells are great for the homeowner because the water is free. Wells are also unpredictable when it comes to the quality of the underground water you are drawing from since the water is not treated by a controlled treatment plant.
Since the quality of water varies from well to well, the home’s plumbing system will react to what it is given. Sometimes this can result in a rotten egg smell coming from fixtures throughout the house. This is more common in well systems than with city water systems.
What the customer is smelling is hydrogen sulfide gas. Hydrogen sulfide gas is a naturally occurring gas produced by water’s decaying chemical reaction with certain rocks and soil. This creates sulfur bacteria. This sulfur bacteria comes straight from the well and into the home’s plumbing system.
Hydrogen sulfide odors require sulfur, hydrogen and bacteria. If you can remove at least one of those three elements from the equation the smell will dissipate.
NARROWING DOWN THE SOURCE
The bacteria coming in from the well may not be the dominant force causing a strong smell in the house. You will have to narrow the biggest source of smell by some simple diagnostics steps. Is it smelling from the cold-water system only? Is there an existing water filter or softener system? Is the smell coming from the hot water distribution system only? Does the smell go away after a few minutes, or does it stay permanently?
First run some cold water out of multiple faucets or spigots in the house. If you get a strong odor when only running cold water, you know the primary source of the smell is coming directly from the well.
Go to where the water enters the house and see if there is a water filtration system. If there is a filtration system of any type, notice whether the entire distribution system runs through this filter or is there a take-off before the filtration system? If there is a takeoff before the filtration system, what fixtures does that takeoff supply? Maybe you are only getting raw unfiltered well water to that specific fixture and it needs to be re-piped. Does the water filtration system need to be replaced? If the well water filtration system needs replacing, the best thing to do is send the water away to be tested. You can’t effectively filter out contaminants if you don’t know exactly what you’re trying to filter out.
HOT WATER SIDE ONLY
If the rotten egg smell is only coming from the hot water distribution system, the issue is coming from the water heater.
A water heater has an anode rod that protects the tank from corrosion by sacrificing itself. This anode rod is typically made from magnesium. Decaying magnesium generates enough hydrogen to create an odor problem. To fix this problem you need to consult with the manufacturer’s instructions on both anode rod replacement and chlorinating the water heater and the plumbing system. Each water heater manufacturer has their own step by step process on how to accomplish these two items and it’s important to follow them to avoid voiding the warranty of the water heater.
Typically, the manufacturer wants you to do two things. First, they want you to replace the magnesium anode rod with a different type of metal anode. Second, they want you to chlorinate the water heater and the connected distribution system.
Replacing the anode rod is a very straightforward task, but one that requires some risk. Most anodes screw out from the top with a hex nut that is visible. The standard size of that hex nut is 1-1/16 inch. I suggest getting a deep well socket with a ½-inch drive breaker bar and applying constant steady pressure for removal. The risk of removing the anode is that it may start to come out and break off at the threads leaving you with a serious leak and a night’s worth of fistfighting to salvage the threads. The homeowner should be made aware of this prior to the attempt (prior to beginning the work and in writing).
To chlorinate the system, the manufacturers often ask you to turn off the power or gas to the unit, drain a few gallons of hot water out of the unit, remove the magnesium anode rod, pour a gallon of bleach into the unit through the hot water outlet, replacing the anode rod with the new manufacturer recommended rod, reconnecting the hot water piping, running the hot water spigots until you get chlorine smell at each spigot, waiting a period of time (usually an entire day), and lastly running a ton of water until all the chlorine is out of the system.
This process will kill the bacteria causing the smell but is not guaranteed to totally get rid of the smell. Sometimes the only cure is to start from the beginning and work your way to the end by having a well company shock the well itself, install/replace/chlorinate the existing water filtration system, chlorinate the water distribution piping and work on the water heater as stated above.
The most important thing to remember is that you are adding nonpotable chemicals into a potable water system that people are going to be drinking and showering after you leave. Make sure you follow every step of the manufacturer’s processes.
