Walk into a house built in the middle of the last century and the water supply is likely copper, or galvanized steel that someone replaced with copper. Copper earned that spot. It resists many forms of corrosion, handles heat well and can be repaired with common fittings. The question homeowners usually ask is whether it is still a good choice, either to keep or to install in a remodel.
What copper does well
Long service life
Properly installed copper in compatible water can last for decades.
Heat tolerance
It handles hot water lines and sunlight exposure without breaking down.
Strength
It resists impact and does not sag between supports.
Familiar repairs
Any plumber can repair or extend it, and fittings are common.
Recyclable
Old copper has scrap value.
Where copper fails
Copper is not immune. Water chemistry, flow velocity and installation quality can all shorten its life. The most common failure is pinhole leaking, a tiny hole that forms from the inside when something in the water pits the pipe wall. Pinholes often start in one spot and appear in others over time.
Other issues include corrosion at joints where different metals meet, erosion from fast flow at elbows and the failure of old solder with lead content in very old systems. Lead solder was banned for potable water lines years ago, but homes with very old copper may still have it.
| Problem | Typical sign | What it points to |
|---|---|---|
| Pinhole leaks | Small wet spots or green stains on pipe | Internal pitting that may spread. |
| Joint corrosion | Crust around fittings | Mixed metals or flux residue. |
| Erosion at bends | Failure at elbows near the heater | High velocity or hot water. |
| Blue-green water | Staining on fixtures | Copper dissolving into aggressive water. |
Seeing pinholes or green stains on copper?
Call and describe where they are.
Should you keep copper or replace it?
One pinhole in an otherwise sound system is a repair. Several in a few years points to a system that is failing. At that point, a partial or whole-house repipe may be better value than a string of repairs. Our repiping page explains how we assess that decision, and our slab leak repair page covers the case where the failing pipe is under the floor.
Copper versus the alternatives
PEX is flexible, cheaper to install and resists scale, but it has its own limits. Copper costs more in materials and labor but has a long track record and tolerates higher temperatures and sunlight. The choice is not about one being better in every case. It depends on your home, the water, the budget and the layout. We lay out the options when we inspect.
How to extend the life of copper
- Keep water pressure within a normal range with a working regulator.
- Avoid mixing dissimilar metals without dielectric fittings.
- Flush the water heater so sediment does not erode the outlet piping.
- Fix small leaks promptly so corrosion does not spread.
- Ask for a pipe inspection if you see blue-green stains or recurring pinholes.
Reading the pipe you have
You can learn a lot from looking at exposed copper under sinks, near the water heater and at the main. Healthy copper is salmon-pink to brown with an even tone. Green or blue crust at fittings suggests a slow weep. White chalky deposits suggest hard water minerals, which are normal near the water heater. Dark pitting or tiny wet beads along a pipe are signs of trouble.
Pipe thickness is labeled on the tube in many cases, with markings indicating type K, L or M. Thicker walls tend to last longer in aggressive conditions, and thin-wall pipe in a home with problem water may fail sooner. If you are not sure what you have, send us a photo.
Soldered joints, lead and older homes
Very old copper systems sometimes joined pipe with solder that contained lead. Modern solder for drinking water is lead-free by law. If your home predates that change and you have never had the water tested, a lab test of a first-draw sample tells you whether lead is present in your water.
A test is the only way to know. Appearance does not tell you, and a clean-looking system can still release lead from old fittings. If the result is a concern, a plumber can identify the source and recommend whether replacing sections is enough.
Copper theft and exposed runs
Copper has scrap value, and exposed copper in vacant or under-construction buildings is a target. If a property is empty during a remodel, closing the main shutoff and securing access reduces the risk of a water loss when pipes are cut. It is an odd reason to prefer another material, but it matters on some jobs.
When to ask for a pipe inspection
If your house has copper that is several decades old and you have seen even one pinhole leak, call a plumber. The inspection covers exposed sections, water pressure and how the pipe behaves under test. The inspection shows whether the problem is localized or system-wide, and it gives you facts for a repair-or-repipe decision. See our repiping page for what that decision involves.
Copper and Monterey Park water
Whether water attacks copper depends on its chemistry, and we do not state a corrosion rating for Monterey Park here. The City of Monterey Park supplies most of the community from local groundwater wells, and its 2010 water quality report listed total hardness around 12 grains per gallon, with a range from 4 to 24. Hardness is one part of the picture, and it tends to leave scale rather than eat pipe.
If you see pinhole leaks, blue-green stains or recurring failures, ask the City's Water Division for its current water quality report and consider a lab test of your tap. Repiping work typically needs a plumbing permit, and the building department can tell you what applies.
Questions about copper pipe in Monterey Park
Often several decades, but it depends on water chemistry, pressure and installation quality.
Internal pitting from water chemistry, flow or deposits. Once started, pinholes often appear elsewhere.
It means copper is dissolving into the water at some point. A plumber can check the cause.
Not automatically. Replace when failures are repeating, not just because the pipe is old.
Ask the City's Water Division for its latest report, or test your tap.
Sources and where to confirm
Local facts and rules on this page rest on the City's 2010 water quality report, the Water Division, the building department and the California Plumbing Code. Confirm anything that affects your own property with the source.
- City of Monterey Park Water Division, water quality report (2010 edition cited here). Ask the Water Division for the current report.
- City of Monterey Park Water Division, for questions about your meter, billing and the utility side of the line.
- City of Monterey Park building department, plumbing permit requirements, including water heater replacement.
- California Plumbing Code (the state's adoption of the Uniform Plumbing Code, UPC), enforced locally by each city's building department.