Road salt corrosion of water in New Hampshire
There are two main factors that contribute to corrosive water for our customers. The most common issue is low pH. If the pH is below 7, it’s acidic. If it’s below 6.5, it’s acidic enough to dissolve copper pipes. Road salt corrosion can also occur in NH well water. Evidence of this is a blue-green-toned residue in sinks, tubs and sometimes in the toilets.
It’s a challenging stain to clean. But what’s more concerning is every little bit of copper that you see collecting in sinks, tubs and toilets is copper that is no longer on your pipes. This can result in brittle pipes or pipes that leak on your plumbing connections. Corrosion happens faster wherever two metals meet such as a plumbing elbow or a mixing valve.
Salt in water corrosion
We tell our customers that salt in their water is naturally occurring, but we don’t always know the origin of the salt. In areas such as Auburn or Tilton, the salt in the water often comes from road salt corrosion.
Yes, it’s important to keep roads safe in winter, but it’s important to note that anything that goes onto roads is likely going to end up in the water table. There are portions of NH with chloride from salt at levels over 1,000milligrams per liter. You know it’s salty by taste.
There are limited treatment options when salt levels in water get extremely high. We can put in a reverse osmosis (RO) system at the point of use for the drinking and cooking water. A RO system can remove more than 90% of the salt from road salt corrosion at the point of use.
Rampant water corrosion
The Environmental Protection Agency’s secondary standard for chloride is 250 milligrams per liter (MPL). At a level of 500 milligrams per liter, corrosion is really rampant, and the water tastes horrible. When chloride levels get up around 1,000 milligrams per liter, treatment options are very limited other than improving the drinking water.
High chloride levels negatively affect water systems and pipes. At 250 milligrams per liter, even with a neutral pH level, there are going to be a bunch of symptoms such as pinhole leaks in pipes. A hot water tank that you would normally expect to last 15 years might last five years.
Water appears to have the same kind of crusty build ups that come with hard water. This can be confusing to some people when they test and think they have hard water. Yet, the hardness isn’t that bad, but you see all the same symptoms of hardness. Salt can do much of the same build ups that hardness can do.
Unfortunately, preventing road salt corrosion of water is very difficult for those on well water. A well generally gets contaminated over time. There are areas in NH and Massachusetts that read “Low Salt” or “Reduced Salt Area or “Sand Only,” because the groundwater has been contaminated with salt.
Testing and treating for road salt corrosion
When was the last time you had your water tested? Road salt is a common problem in NH wells because of long winters, but salt stays at the ground level year round. You may see chloride spikes in spring and summer depending on the water table. Unfortunately, by the time many homeowners detect there’s serious salt corrosion in pipes and the water system, there’s a flood in the home.
One option for those with copper pipes and water that regularly gets corrosive from chloride is to switch to cross-linked polyethylene pipe. With that switch, you’re still going to have corrosion on individual faucets, fixtures and hot water tanks, but you’re not going to have pinhole leaks that will occur with copper pipes getting corroded. (Secondwind does not replace copper with polyethylene pipe.)
Secondwind’s water treatment experts suggest an acid upflow neutralizer for homes where the pH level is below 7. This option does not remove the salt; it passivates the plumbing. If there’s no passivation in your plumbing and you’ve got salty water, the salt is going to eat through the copper. When we install an acid neutralizer, we can actually passivate the inside of a pipe, which means creating a protective layer of calcium buildup. It’s the opposite of softening the water. We’re actually adding hardness to the water in order to protect the pipes.
It’s important to remember that every case is unique. There are different types of salt that corrode wells and water systems. In some cases, a neutralizer is a solution; for others, it’s a water softener. Secondwind’s experts will guide you through the best solution for your drinking water.