Why Does My Water Smell Like Rotten Eggs?

You turn on the tap in your Sacramento home, and instead of clean, neutral-smelling water, you get a noseful of something that smells like rotten eggs. It’s sharp, sulfur-like, and honestly hard to ignore. Drinking it is unappealing, showering in it feels gross, and if guests notice it, it’s embarrassing.

That smell is usually not your imagination and it’s not “just how water is here.” It has a specific cause, and in most cases it can be fixed with the right diagnosis and treatment.

This guide breaks down why water in the Sacramento area sometimes smells like rotten eggs, how to narrow down the source, when it might be a health concern, and what practical steps you can take to solve it — from DIY checks to professional treatment options.

First things first: what is that rotten egg smell?

That “rotten egg” odor in water is almost always caused by hydrogen sulfide (H₂S) gas or sulfur-related bacteria.

Hydrogen sulfide can get into your water in a few ways:

• It can occur naturally in groundwater as water moves through soil and rock containing sulfur-bearing minerals.
• It can be produced by sulfur-reducing bacteria living in low-oxygen environments like wells, water heaters, or sections of plumbing where water sits. Even at very low levels, hydrogen sulfide can produce a strong odor. Your nose is extremely sensitive to it; you can smell it at concentrations far below what typical drinking water standards consider a health concern.

But here’s the key point:
The smell tells you something is off — with your water source, your plumbing, or your water heater. You shouldn’t ignore it, especially if it shows up suddenly or gets stronger over time.

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How Sacramento’s water setup plays into this

Understanding where your water comes from helps explain why some homes in and around Sacramento are more prone to sulfur smells than others.

For most homes inside the City of Sacramento:

• About 80% of the drinking water comes from the American and Sacramento Rivers.

• About 20% comes from groundwater wells. Sacramento County Water Agency and other local districts also rely on a mix of surface water and groundwater for surrounding communities. What this means for you:

• If you’re on city water inside Sacramento city limits, your water is treated and monitored to meet state and federal standards. Hydrogen sulfide at the treatment plant is typically controlled, but odor can still develop inside your home’s plumbing or water heater.

• If you’re on a private well (more common on the outskirts — parts of Elk Grove, Rio Linda, Wilton, Herald, rural pockets of South Sacramento and beyond), you’re responsible for your own water quality. Groundwater in some areas is more likely to contain hydrogen sulfide and sulfur-reducing bacteria, which can cause persistent odors. So the same smell can have different root causes depending on where you live and how your home is supplied.

Step one: pinpoint where and when you smell it

Before you start replacing parts or shopping for filters, you need a basic diagnosis. That starts with a few simple checks you can do in under 10 minutes.

1. Does it smell in hot water only?

If the rotten egg smell shows up only when you run hot water, but cold water from the same faucet smells normal, your water heater is the prime suspect.

Most likely causes:

• Reaction between the heater’s sacrificial anode rod (usually magnesium) and naturally occurring sulfate in the water, producing hydrogen sulfide.
• Sulfur bacteria colonizing the tank interior, especially if it’s been set at a low temperature or left unused for long stretches.

In Sacramento homes, this is common in:

• Older water heaters
• Heaters set below 120°F for “energy saving”
• Homes that sat vacant for months before you moved in

In this case, treating the water heater can dramatically reduce or eliminate the smell, without needing to overhaul your whole plumbing system.

2. Does it smell in both hot and cold?

If both hot and cold water smell like sulfur:

• The issue is likely in your water supply (well or incoming city line) or in your home’s plumbing system as a whole.
• If neighbors on the same block notice the same thing at the same time, it may be a system-level issue (rare, but possible), especially after main repairs or seasonal changes in source water conditions.

If you’re on a private well and both hot and cold smell, assume it’s either:

• Hydrogen sulfide naturally present in the groundwater, or
• Sulfur bacteria in the well, plumbing, or pressure tank.

3. Does it smell at every faucet — or only one?

If only one sink or shower smells like rotten eggs, but others in the house are fine, that points to:

• Bacteria in the fixture, aerator, or a short stretch of pipe
• A drain issue (the smell might be coming from the drain, not the water)
• A seldom-used branch of plumbing with stagnant water

Quick test:

1. Fill a clean glass with water from the suspect faucet.
2. Walk away from the sink and smell the glass.
   • If the smell is strong at the sink but faint from the glass a few feet away, it may be the drain.
   • If the smell is strong from the glass, the issue is in the water supply or plumbing, not the drain.

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Is rotten egg smell in water dangerous?

Hydrogen sulfide can be a health concern at high concentrations, especially in enclosed, poorly ventilated spaces. At typical household levels in water, it’s primarily an aesthetic and corrosion issue rather than an acute poisoning risk, but that doesn’t mean you should ignore it.

Key points:

• Low levels:
  • Unpleasant smell and taste
  • Can make drinking water effectively unusable
  • Can tarnish silverware and discolor fixtures
  • Can corrode metal pipes, water heaters, and appliances over time
• Higher levels or long-term exposure:
  • Can aggravate nausea or headaches in sensitive individuals
  • Accelerates corrosion, increasing risk of leaks and failure in plumbing and gas-burning equipment connected to water heaters

If you’re relying on well water and you notice a strong sulfur odor, treat it as a sign that you need comprehensive testing, not just for hydrogen sulfide but also for bacteria, nitrates, and other contaminants. Sacramento-area well owners are strongly encouraged by the State to test regularly. Bottom line:
Even if the smell alone isn’t likely to send you to the ER, it’s a quality-of-life issue and a long-term system health issue. Fixing it protects both your home and your comfort.

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Why Sacramento homes are prone to sulfur odors

Several factors make the broader Sacramento region a candidate for sulfur-smelling water in certain homes.

Groundwater and local geology

Surrounding parts of Sacramento County and nearby rural areas rely heavily on groundwater wells. As groundwater moves slowly through soil and rock, it can pick up minerals and interact with organic material. Under low-oxygen conditions, this can support sulfur-reducing bacteria and generate hydrogen sulfide. If your home or property:

• Uses an older well
• Hasn’t had the well inspected or disinfected in years
• Sits in an area with naturally higher sulfur or iron content

…then persistent rotten egg odor is a predictable outcome, not a random event.

Seasonal changes and surface water

For city water users, Sacramento’s primary sources — the American and Sacramento Rivers — can experience seasonal changes in algae and organic matter, especially during hotter months and lower flows. While treatment plants are designed to remove these and re-oxygenate the water before it enters the system, taste and odor events can still occur in distribution and at the tap, especially if water has spent longer in pipes or storage. These events are usually short-lived and often harmless from a regulatory standpoint, but your nose doesn’t care about compliance tables; it just reacts to the smell.

Aging plumbing and water heaters

Many Sacramento neighborhoods combine:

• Older galvanized or copper pipe
• Original or long-overdue water heaters
• “Energy saving” temperature settings that are too low to discourage bacterial growth

That mix is ideal for:

• Bacteria colonizing dead legs of plumbing (sections that rarely see flow)
• Hydrogen sulfide production inside the water heater tank

When you turn on the tap, you’re essentially venting the gas out of the water into your kitchen or bathroom.

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Common causes, broken down by scenario

Let’s map the typical “smell patterns” to the most likely causes.

1. Smell in hot water only → water heater

If the smell disappears when you run cold water, focus on the heater.

Likely mechanisms:

• Anode rod reaction: Magnesium anode reacts with sulfate in the water, creating hydrogen sulfide gas.
• Warm, low-oxygen tank: Perfect environment for sulfur-reducing bacteria if the temperature is kept too low or the tank is never flushed.

Typical Sacramento fix strategies:

• Flushing the tank to remove sediment.
• Temporarily shock treating the heater with a proper disinfectant (this should be done carefully and correctly, usually by a pro).
• Replacing the anode rod with an aluminum-zinc alloy rod, which is less likely to support sulfur odors in many water chemistries.

If the heater is old and heavily corroded, replacement may be more cost-effective than repeated temporary fixes.

2. Smell in both hot and cold at all faucets → source or main plumbing

Here, you’re looking upstream of the water heater.

Possible sources:

• Hydrogen sulfide in the well water or incoming city supply.
• Bacterial growth in the pressure tank, storage tank, or main plumbing lines.
• In rare cases, a distribution system issue affecting multiple homes.

Action steps:

• If you’re on city water and several neighbors have the same problem, report it to your water provider and get a plumber involved if the utility confirms their side is fine.
• If you’re on a private well, schedule a comprehensive water test (not just a cheap test strip) and plan on a combination of disinfection and treatment.

3. Smell at one fixture only → local plumbing or drain

If only one bathroom sink or one shower smells:

• Remove and clean the aerator and showerhead.
• Run hot water for several minutes to purge stagnant water.
• Clean the drain thoroughly; biofilm in the drain line can produce sewer-like or sulfur odors that mimic a water problem.

If the smell persists in the water itself from that fixture, you may have a localized bacterial issue in that branch line, which may require targeted disinfection or, in some older homes, partial repiping.

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How professionals typically solve rotten egg odor in Sacramento homes

A competent Sacramento plumber or water treatment specialist doesn’t just throw a filter at the problem. They start by testing and isolating the cause.

Here’s the typical process:

1. Interview and pattern mapping

   • When did you first notice the smell?
   • Is it worse in the morning, after vacations, or after heavy use?
   • Is it only in hot water, only in certain bathrooms, or everywhere?

2. Onsite tests

   • Check hot vs cold at several fixtures.
   • Run the glass test away from drains.
   • In well systems, test for hydrogen sulfide, iron, manganese, pH, and bacteria.

3. Physical inspection

   • Inspect the water heater age, settings, and condition.
   • Check for dead legs or old capped lines.
   • Inspect aerators, showerheads, and accessible plumbing.

4. Treatment plan

Depending on what they find, a typical Sacramento treatment plan might include:

• Water heater-only solutions

  • Raise temperature to a safe but bacteria-unfriendly range (often around 130°F, with scald precautions).
  • Flush the tank thoroughly.
  • Replace the anode rod with an aluminum-zinc type or, in specific cases, use a powered anode.
  • Disinfect the tank following manufacturer-safe procedures.

• Whole-house solutions for well water or persistent issues

  • Shock chlorination of the well and plumbing to knock down bacterial populations (done correctly, not just pouring bleach in the well cap and hoping for the best).
  • Installation of a backwashing oxidizing filter (e.g., air-injection, catalytic media) that converts hydrogen sulfide into elemental sulfur and filters it out.
  • Activated carbon filtration to polish taste and odor after oxidation.
  • In some cases, continuous chlorination or peroxide injection with proper contact time, followed by carbon filtration.

For serious, persistent sulfur issues in well water, a single under-sink carbon filter is rarely enough. The problem needs to be treated at the point of entry so every tap, shower, and appliance benefits.

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When should you handle it yourself — and when should you call in help?

Some steps are reasonable for a homeowner with basic tools and common sense. Others are worth outsourcing to avoid damage, unsafe chemical handling, or incomplete fixes.

Reasonable DIY steps:

• Confirm whether it’s hot-only, cold-only, or both.
• Check one faucet vs whole house.
• Clean aerators and showerheads.
• Clean drains and overflow openings where biofilm may be living.
• Flush rarely used lines by running water for several minutes.

Worth calling a pro for:

• Persistent odor in both hot and cold throughout the home
• Well water with recurring sulfur smells
• Situations where the odor returns quickly after DIY flushing or cleaning
• Water heater disinfection and anode rod replacement if you’re not comfortable working on gas or high-voltage equipment
• Designing and installing whole-house treatment systems

If you’re already at the point where the smell is affecting your daily life — cooking, showering, doing laundry — you’re past the “wait and see” stage. At that point, asking a professional for a structured diagnosis is more efficient than buying random filters and hoping one works.

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Practical tips and best practices for Sacramento homeowners

To wrap this up, here are concrete steps and habits that actually move the needle if you live in Sacramento or nearby and your water smells like rotten eggs.

1. Start with a quick home diagnosis

Within one day, you should know:

• Whether the smell is hot water only or both hot and cold
• Whether it’s one fixture or the entire house
• Whether neighbors are noticing the same thing

Those three observations dramatically narrow down the problem, and they’re exactly what a good plumber will ask you anyway.

2. Don’t ignore your water heater

Your water heater is not a “set it and forget it” appliance, especially in older Sacramento homes.

Solid practices:

• Keep the temperature at a reasonable level (often around 120–130°F; hotter requires scald precautions).
• Flush the tank annually (or more often if you have hard water or visible sediment).
• If you’ve had sulfur odor issues, ask about an aluminum-zinc anode rod or a powered anode that plays better with your specific water chemistry.

A heater that’s never been serviced is almost guaranteed to be part of the problem.

3. If you’re on a well, test like you mean it

For private wells around Sacramento:

• Schedule comprehensive water testing, not just cheap strips. Make sure hydrogen sulfide, iron, manganese, pH, and bacteria are included.
• Repeat testing after any major changes (pump replacement, flooding events, nearby construction).
• Plan for a real treatment strategy, not just piecemeal filters under a single sink.

Well owners are, effectively, their own water utility. If your water smells like rotten eggs, that’s your warning light on the dashboard.

4. Treat the cause, not just the symptom

A scented pitcher filter or fridge dispenser does not solve a systemic hydrogen sulfide problem.

Long-term, reliable solutions usually involve:

• Fixing plumbing or equipment issues (heater, dead legs, contaminated tanks)
• Implementing point-of-entry treatment for larger problems (oxidation plus filtration)
• Following up with maintenance so the problem doesn’t bounce back

Think in terms of system health rather than spot-fixing one faucet.

5. Use professionals strategically

If you bring in a local Sacramento plumber or water quality specialist, make the most of the visit:

• Be ready with notes on when and where you smell the odor.
• Ask for testing results in writing and a clear explanation of options, including up-front and long-term costs.
• Prioritize solutions that address both the odor and system longevity — for example, treating hydrogen sulfide while also reducing corrosion and protecting appliances.

The goal is not just “less smell this week.” It’s cleaner, more reliable water for years, fewer surprises, and less hidden damage inside pipes and equipment.

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Final thought: you don’t have to live with rotten egg water

If your Sacramento home’s water smells like sulfur, that’s not just an annoyance you need to tolerate. It’s a diagnostic clue that something in your water supply, plumbing, or equipment is out of balance.

By:

• Noticing where and when the smell occurs
• Understanding how local water sources and your home’s setup factor in
• Taking smart initial steps and then bringing in qualified help when needed

…you can turn “gross, smelly water” back into something you’re comfortable drinking, cooking with, and showering in every day.

If the smell is already driving you to bottled water or making you dread showering, that’s your signal. Get a proper diagnosis, map out a real fix, and restore your water to what it should be: clean, safe, and odor-free.