Hard Water: Elements that Corrode Pipes and Treatment Solutions

Written by AOS Treatment Solutions on June 23, 2017
corrosion control
Solving hard water issues is one of the most difficult realities municipalities must deal with in respect to potable water.
The majority of mineral elements are removed because of the fact that they smell and taste bad and discolor water. More costly however, many elements found in our drinking water destroy infrastructure through galvanization and build up.
However, corrosion is equally devastating.
And metal pipe corrosion can actually be a consequence of treating water for mineral and iron removal.

How Hard Water Destroys Municipal and Residential Infrastructure

Municipalities with failing water delivery systems are victims of one of two symptoms of hard water: galvanization (build up) and/or corrosion. Hard water can galvanize to metal pipes and build up in plastic piping or it can corrode pipes from the inside out.

In order to treat hard water, chemicals like chlorine, chlorine dioxide and potassium permanganate are often added to water in order to soften it. But, while these chemicals — in association with a filter — remove the iron, manganese and other elements that make water unpalatable, they also change the pH and can make them acidic.
Making water more acidic can lead to pipe corrosion.

Consequences of Corrosion

While both build up and corrosion are extremely damaging and typically require pipe replacement, corrosion can lead to catastrophic failures.
Unlike galvanization and buildup, corrosion does not typically produce obvious symptoms prior to a major break because the rot comes from the inside. Whereas buildup becomes apparent over time because water pressure slowly changes, corrosion from the inside does not affect the delivery of water until there is a break.
Because of corrosion, broken water mains under roads, breaks next to and below roads and swells under and beside overpass and bridge abutments can occur with little to no warning.
And, once it is determined that breaks are occurring because of pipe corrosion, there is little that can be done except replace the pipe. But, prior to replacing the pipe, the corrosive elements in groundwater must be removed via water treatment.

Most Common Corrosive Catalysts in Municipal Water

It is far from the truth to say that treating water is the only factor that leads to pipe corrosion. There are a variety of factors that can lead to pipe corrosion.
From pH, alkalinity and organics to salts and chemicals dissolved in the water, different components of a water supply can corrode pipes for different reasons.
The physical properties of the water – the temperature, gases and solid particles – can also contribute to corrosion, as “the tendency of water to be corrosive is controlled principally by monitoring or adjusting the pH, buffer intensity, alkalinity, and concentrations of calcium, magnesium, phosphates, and silicates in the water.”
In the same light, that water itself can be corrosive: “Actions by a water system to address these factors can lead to reduced corrosion by reducing the potential for the metal surface to be under the influence of an electrochemical potential.”
As there are a wide variety of factors that can lead to corrosion, a number of solutions are required.

Means of Preventing Corrosion

Before deciding what means to use in order to prevent corrosion, it must first be determined what is causing the corrosion. AOS Treatment Solutions utilizes a variety of methods to diagnose corrosion and evaluate the reasons why corrosion has occurred.
Some techniques utilized in the corrosion control process may include redesigning the plumbing system, adding corrosion inhibitors and making water quality modifications. We may also use cathodic protection and a variety of coatings and linings.
AOS Treatment Solutions can provide on-site testing with state-of-the-art equipment and expertise to determine the best treatment plan to inhibit corrosion in a cost-efficient and environmentally safe manner. Contact AOS Treatment Solutions for more information regarding corrosion control for groundwater.
Posted Under: Corrosion Control