Seeing yellow or brown water come out of the tap can be unsettling, but in most homes, this change has common, non-dangerous explanations.
What it usually means:
Discoloration is most often caused by sediment or rust that has been stirred up somewhere along the water’s path. This can happen after nearby construction, routine hydrant flushing, or water main work. In older buildings, rust inside pipes can temporarily discolor water when flow or pressure changes.
What it might mean:
If the color appears only in hot water, the source may be your building’s hot water system or heater. If it appears only in one faucet, the issue is likely localized to that fixture or section of pipe. If it affects the whole building at once, it’s often related to city or building maintenance.
What to do next:
Run cold water for a few minutes and see if the color clears. Avoid doing laundry until the water runs clear, as sediment can stain fabrics. If the issue resolves quickly, it’s usually temporary.
When it’s nothing:
Short-lived yellow or brown water—especially after construction or overnight—is extremely common in older buildings and usually harmless once flushed out.
When to get a professional opinion:
If discoloration lasts more than a day, keeps returning, or comes with particles that don’t settle out, it’s reasonable to notify building management or have a plumber assess internal pipes.
Cloudy water often looks alarming at first glance, but it is one of the least concerning tap changes.
What it usually means:
Most cloudy or milky water is caused by tiny air bubbles trapped in the water. This can happen after pressure changes, plumbing work, or temperature differences. If you pour the water into a glass and it clears from the bottom up within a minute or two, air is the cause.
What it might mean:
In rare cases, cloudiness that doesn’t clear can be due to fine sediment or mineral content. This is uncommon in city-treated water but can occur in certain building systems.
What to do next:
Let the water sit in a clear glass. If it clears quickly, there’s nothing you need to do. Running the tap briefly can also help release trapped air.
When it’s nothing:
If the cloudiness disappears on its own and doesn’t affect taste or smell, it’s simply air—and completely harmless.
When to get a professional opinion:
If cloudiness persists, doesn’t clear, or is accompanied by taste or odor changes, it’s worth asking your building or water provider for guidance.
Unusual smells or tastes are often more noticeable than visual changes—and they can feel personal because they affect drinking and cooking.
What it usually means:
A chlorine or “pool-like” smell often increases seasonally or after treatment adjustments. An earthy or musty smell can come from natural changes in water sources, not from contamination. Metallic tastes are frequently linked to plumbing materials or water sitting in pipes.
What it might mean:
After plumbing repairs, tastes can change temporarily due to disturbed pipes or new fittings. Hot water may taste different than cold water if the source is a building system.
What to do next:
Try running cold water for a minute and tasting again. Compare different taps. Use cold water for drinking and cooking, especially after periods of non-use.
When it’s nothing:
Mild, temporary taste or odor changes—especially after maintenance—are common and usually resolve on their own.
When to get a professional opinion:
If strong odors persist, worsen, or are accompanied by discoloration or health symptoms, contact building management or your local water provider.
Some tap changes follow daily patterns rather than sudden events.
What it usually means:
Morning discoloration often happens because water has been sitting overnight in internal plumbing, especially in older buildings. Pressure drops can occur during peak usage times or maintenance. Slow hot water is common in shared systems.
What it might mean:
If issues are isolated to your unit, internal pipes or fixtures are likely involved. If neighbors experience the same thing, the cause is usually building-wide.
What to do next:
Run cold water briefly in the morning. Note when issues happen and whether they repeat. Ask neighbors if they’re seeing the same thing—this often provides instant clarity.
When it’s nothing:
Patterns that repeat predictably and resolve quickly are usually part of normal system behavior.
When to get a professional opinion:
Persistent pressure loss, repeated discoloration, or changes that don’t improve over time justify asking a plumber, building superintendent, or water provider to take a look.
Most tap changes are signals, not emergencies.
Understanding what you’re seeing is often all you need to feel comfortable again.
KnowYourTap.org exists to replace worry with context—and confusion with clarity.