If you live in Cobb County or Northwest metro Atlanta and your home has copper pipes, you’ve probably heard about “pinhole leaks.” Maybe you’ve had one or more leaks and are considering having a whole home repipe. Here’s what’s really going on and what you can do about it.
The Issue Isn’t Your Plumbing. And it isn’t the Water.
The copper pipe systems in many Cobb County homes weren’t installed incorrectly. Most of them were done according to code with materials that were standard for the time. But over the years, we’ve learned that the water chemistry in our area doesn’t always play nice with copper pipes.
Cobb County-Marietta Water Authority (CCMWA) treats the water using chemicals like chlorine dioxide. These chemicals are great at keeping the water safe to drink. But they’re also corrosive over the long haul especially in soft water that doesn’t naturally form protective scale inside the pipes.
The result? The inside of the copper pipe slowly thins out until tiny holes aka pinhole leaks start appearing. These leaks can show up under slabs, in walls, or in ceilings. And once they start, they tend to keep happening until the whole system is compromised.
Why No One Will Pay for It (Except the Homeowner)
This is where it gets frustrating.
● The water authority isn’t liable. Their job is to provide water that meets all federal and state safety standards—which they do. The law doesn’t require water that’s “pipe friendly,” only water that’s safe to drink.
● The pipe manufacturers aren’t on the hook either. The copper pipe they sold met code and passed all the required quality checks. They didn’t sell a defective product.
● That leaves homeowners holding the bag, even though the root cause wasn’t something they could have predicted or prevented.
So while the water is legal and the pipe was legal, the two haven’t worked well together in some parts of Cobb County. That mismatch is what’s leading to the widespread failures we’re seeing now.
What You Can Do
If you’ve had one pinhole leak in your copper pipe, it may be a matter of time before more appear. At that point, you’re facing not just the cost of repairs but water damage, insurance claims, and all the stress that comes with those.
We recommend repiping before the damage gets worse. At Plumbing Express, we offer whole-home and partial repipes using modern materials that are more resistant to the chemicals in Cobb’s water like FlowGuard Gold® CPVC and Uponor PEX Type-A.
Some homeowners also choose to:
● Install a smart leak detection valve that shuts off water automatically if a leak is detected
● Add whole-house filtration to reduce chemical exposure
● Avoid water softeners, which can make copper even more vulnerable
Is Your Home at Risk?
If you live in unincorporated Cobb County or in Acworth, Kennesaw, Powder Springs, Dallas, or Mableton, your water comes from CCMWA. That means your pipes may be exposed to the same conditions that have caused problems in thousands of homes across the area.
If you’re starting to see signs leaks, discolored pipe, signs of mold, or increasing water bills, it may be time to talk with us about leak detection and your other options. The earlier you catch it, the more control you have over the process and cost.
Why Are Copper Pipes Failing in Cobb County Homes?
If your home has copper water pipes and you’ve experienced mysterious leaks—especially small “pinhole” leaks in walls, ceilings, or under slabs—you’re not alone. Many homeowners in Cobb County and Northwest metro Atlanta are dealing with this frustrating problem. Here’s what you need to know:
It’s Not Bad Plumbing—It’s the Water
The issue isn’t that your pipes were installed incorrectly. In fact, many homes with pinhole leaks had professional installations that followed industry standards. The real problem is that our region’s treated water, while safe to drink, can be chemically aggressive toward copper over time.
Cobb County’s water is treated to keep it clean and safe, but the water is soft (low in minerals) and slightly alkaline. That combination doesn’t allow the thin protective coating that usually forms inside copper pipes to develop. Over the years, this can lead to corrosion from the inside out, even in high-quality copper.
In some areas, the problem is made worse when water sits still in pipes (like in rarely used bathrooms), or when disinfectant levels drop in parts of the system. This can allow conditions that speed up corrosion—even though everything still looks normal on the outside.
Who’s Responsible?
This is the part many homeowners find surprising—and frustrating.
● The water authority (CCMWA) is not liable, because the water meets all federal and state safety standards. They are required to deliver water that is safe to drink, not water that guarantees zero pipe corrosion in every home.
● The copper pipe manufacturers also aren’t responsible, because the pipes meet national plumbing codes and passed all required certifications at the time of sale. They weren’t defective—they just aren’t always a good match for the local water chemistry over the long haul.
● Homeowners are left responsible for replacing the pipes, even though the root cause was out of their control.
In short, this is a known but unassigned problem: the water is legal, the pipe is legal, and yet they haven’t played well together in some neighborhoods.
What Can Be Done?
If your home is experiencing repeat copper leaks, it may be time to consider a long-term solution. At Plumbing Express, we offer whole-home and partial repipes using materials better suited to the water conditions in our area—like FlowGuard Gold® CPVC or Uponor PEX Type-A. These modern materials are chemically resistant and engineered for decades of reliable performance.
Steps to possibly help slow the damage include: eliminating water softeners, adding whole house water filtration that remove chlorine and chloramine. Add a smart shutoff valve that will close the water supply instantly when a leak is detected.
How do I know if my pipes could be affected?
The Cobb County Water System (CCWS) provides water service to over 197,000 homes and businesses in unincorporated Cobb County and the cities of Acworth, Kennesaw, Powder Springs, and Mableton . CCWS purchases treated water from the Cobb County-Marietta Water Authority (CCMWA), which also supplies water to nine other municipalities and one corporation within Cobb County and neighboring counties .
