What causes a rotten-egg odor in my tap water?
That rotten-egg smell at the faucet usually comes from hydrogen sulfide, often just called sulfur. Sulfur is a naturally occurring mineral found in many water supplies, and its odor now and then shows up at fixtures in homes and businesses. When the water holds enough oxygen, sulfur stays bound to that oxygen and has no smell. Without oxygen, though, conditions can shift it into a hydrogen-bound form, hydrogen sulfide, which gives off the familiar rotten-egg odor. The smell is unpleasant, but the water remains safe to drink. It may be little consolation, but the problem pops up at random in water systems all over the country.
How does the city reduce the odor?
Along with every standard practice a safe drinking water system must follow, the city increases disinfection at stations around town when needed and scours its distribution mains with high-velocity flushing.
Why do I smell sulfur in the cold water too, not just the hot?
Most likely you are noticing hot water left in the pipes. Let the cold tap run a little longer and the smell should fade. Outdoor spigots are connected straight to the cold supply, so they rarely have a sulfur odor; checking one can help you confirm whether your water heater is the source.
What can I do about the odor?
A few simple steps can help. If you notice the smell only in hot water, start by opening the hot taps throughout the house and letting them run until the water turns cold. This flushes the water heater and may reduce the odor over time. You may need to repeat it, and doing it on a regular schedule can keep the tank clear. Raising the water heater temperature for a few hours before flushing can also help; just take care, because water at the taps will be scalding while the setting is turned up.
You can also ask a plumber to take out the magnesium anode rod in your water heater and install an aluminum one instead. Water heaters ship with a magnesium rod, which can turn dissolved sulfur into a gas and produce the smell at the tap.
When the cold side, or both sides, smell, something in the home's plumbing may be converting sulfur into hydrogen sulfide. Typically this is confined to one or a few fixtures where sulfur-reducing bacteria have taken hold. This is harder to fix: a licensed plumber usually needs to disinfect the household plumbing, commonly with a chlorine solution, and then flush the lines thoroughly to clear out all of the disinfectant.
What if the smell won't go away?
Call Environmental Services at (555) 010-1261 or Water Utilities at (555) 010-1903, and a staff member will follow up to talk through your situation. Staff cannot come inside to work on private plumbing, but they are glad to discuss the problem and share as much guidance as they can to help you get rid of the odor.
Is Fredville's tap water safe to drink?
Public Works does everything required to deliver safe water to residents, free of unpleasant odors, tastes and color. Public water systems must also meet strict standards from both the Texas Commission on Environmental Quality (TCEQ) and the federal Environmental Protection Agency. Samples are tested on daily, monthly, quarterly and yearly schedules. The city's annual water quality report lists the parameters tested and the laboratory results.
Both the state environmental quality agency and the EPA's safe drinking water program publish more information online about water quality monitoring and testing requirements.
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