Water System Corrosion Control Treatment Optimization

Project typeWater
Project value$13 million
Project scheduleSpring/Summer 2026
Contractor nameLD Docsa Associates, Inc.

Photo of a series of pipes set up during testing to optimize corrosion control treatment.

The City of Kalamazoo is implementing a phased update to the public drinking water system to further strengthen corrosion control and protect public health.

Since 1956, Kalamazoo has used phosphate treatment to control corrosion and sequester naturally occurring iron in drinking water. After nearly a decade of study and testing, conducted in cooperation with the Michigan Department of Environment, Great Lakes, and Energy (EGLE), the City is transitioning to a more optimized corrosion control approach tailored to Kalamazoo’s groundwater chemistry and water system.

What Is Changing?

The City is updating the type of phosphate used in drinking water treatment.

Previously, treatment primarily used polyphosphate, which is effective at keeping iron dissolved in water (iron sequestration). The updated treatment will primarily use orthophosphate, which is more effective at forming a protective lining on the inside of pipes.

This protective lining reduces direct contact between water and metal surfaces, significantly lowering the risk of metals, especially lead, leaching into drinking water from older pipes, service lines, plumbing solder, or fixtures. The new treatment will still include a polyphosphate component, meaning iron sequestration benefits will continue.

Why Is This Important?

Corrosion control is a safe, proven, and commonly used water treatment process across the country. It is one of the most effective tools water systems have to protect against lead exposure, even in communities with older infrastructure.

Optimizing corrosion control helps ensure that drinking water remains safe as it travels from treatment plants through distribution pipes and into homes and businesses.

This treatment update also complements the City’s ongoing commitment to replace every lead water service line in the system. Enhanced corrosion control provides an added layer of protection for customers while lead service line replacement work continues.

What Facilities Are Being Updated?

Upgrades are being completed at all 13 drinking water treatment plants in Kalamazoo’s system. As part of the project, phosphate storage and injection systems are being upgraded to current standards, including the addition of modern automation to ensure consistent and precise treatment.

The total project investment is approximately $13 million, funded through the City’s water utility and supported by customer rates, which are reinvested into maintaining and modernizing the drinking water system.

How Was the Treatment Selected?

This update follows nearly 10 years of study, beginning in 2016, including: Chemical analysis, two rounds of solubility testing, coupon rack testing, and an evaluation of treatment performance on steel, brass, galvanized metal, lead, and other materials present in the water system.

Review Corrosion Control Studies

Testing confirmed that this optimized treatment approach is best suited to Kalamazoo’s groundwater chemistry and infrastructure.

What to Expect During Implementation

The updated treatment is being rolled out in phases by service area. You can search for your address using the map linked below (please note it may take a moment to load).

View Update Schedule

During the transition, some customers may notice temporary aesthetic changes, such as discolored water. These changes are not a health concern and may occur when mineral deposits inside pipes are disturbed.

In many cases, discoloration clears on its own. If water use is low, flushing cold water from a faucet for several minutes may help clear the line. In some situations, City crews may perform localized water main flushing to restore normal water appearance.

Residents experiencing water quality concerns are encouraged to report them by calling 311 or (269) 337-8000.