A Manhole Rehabilitation Solution for Concrete Corrosion Repair

April 29, 2026

A Manhole Rehabilitation Solution For Concrete Corrosion Repair

Deep within a chemical processing facility, a severely deteriorating manhole posed a serious threat to ongoing operations. Continuous exposure to heat and hydrogen sulfide (H2S) corrosion had weakened the structure, increasing the risk of failure, costly downtime and complex repairs. With no room to risk excavation or disruption, the damage was urgent. Was there a viable path forward for concrete corrosion repair without tearing up surrounding infrastructure? HK Solutions Group’s corrosion-resistant manhole rehabilitation solution proved to be the answer this industrial facility needed to avoid disaster and restore concrete infrastructure to prime condition.

What Causes Corrosion In Concrete Sewer Systems?

Concrete corrosion is often driven by hydrogen sulfide gas in environments where moisture, heat and chemicals are present. Over time, H2S can convert into sulfuric acid and begin deteriorating concrete surfaces, breaking down the material and compromising structural integrity.

H2S corrosion is common in both municipal sewer systems and industrial underground infrastructure, especially in facilities handling wastewater or chemical discharge. For the chemical processing facility in question, corrosion reached a critical point, requiring concrete corrosion repair before deterioration led to major damage on the facility floor.

Why Is Hydrogen Sulfide Dangerous In Sewer Systems?

Hydrogen sulfide corrosion significantly degrades sewer infrastructure over time. As pipes, manholes and other structures deteriorate, the entire system becomes increasingly vulnerable to collapse, leakage, infiltration and other costly, dangerous operational failures.

In a chemical processing facility, this level of corrosion can quickly escalate from a maintenance issue to a critical operational risk. Structural failure, unplanned downtime and exposure to hazardous conditions are all real possibilities if left untreated. Without corrosion-resistant manhole rehabilitation, concrete infrastructure remains susceptible to disaster.

An Industrial Manhole Rehabilitation Challenge Caused By H2S Corrosion

In the case of the industrial chemical processing facility, traditional repair methods requiring excavation or system shutdown were off the table. The facility needed a solution that could address concrete corrosion repair from within, without disrupting operations or disturbing critical equipment. Add in the unique challenges of the environment, and it was clear specialized treatment was required. Many factors needed to be taken into consideration, including:

• Aging Facility and Structures - This facility, located near Topeka, Kansas, was built in the 1950s and was more than sixty years old at the time of this project. The manhole was lined with acid bricks. Although these bricks were specially designed to resist chemical and thermal corrosion, they were deteriorating after decades of wear and exposure to strong chemicals.
• Significant Chemical Corrosion - The manhole was part of a process-water discharge system with high sulfuric acid content. Sulfuric acid has a very low pH and is very corrosive. The resulting H2S corrosion was causing significant infiltration and inflow issues.
• Extreme Heat - The wastewater in the system was around 140°F, too hot for traditional rehabilitation techniques such as a spray-on manhole lining. Any rehab solution needed to be resistant to both the corrosive properties of acidic chemicals and high temperatures.
• Complex Infrastructure - Because of this manhole’s location in the facility, it would have been extremely costly and difficult to replace. Excavation to dig up and replace the manhole was not an option, as it would have required a multi-day shut-down, involving relocating large, expensive pieces of industrial equipment, navigating existing underground infrastructure and working near dangerous explosive chemicals.

The business owners knew they needed to repair or replace this manhole in order to continue the plant’s operations successfully, but they simply couldn’t figure out a safe, affordable and viable manhole rehabilitation option. HK Solutions Group’s innovative manhole lining process stood out as the safest, most efficient solution to restore the failing manhole with minimal impact to the surrounding plant.

Monoform PLUS™ Manhole Lining For Corrosion-Resistant Manhole Rehabilitation

For projects involving high heat, high acidity and complex infrastructure, HK’s innovative Monoform PLUS™ manhole lining solution serves as a 100% structural and 100% corrosion-resistant manhole rehabilitation method forgoing excavation. Monoform PLUS™ is designed to withstand challenging conditions, making it the perfect option to restore the Topeka-area chemical plant’s deteriorating manhole. Along with being a trenchless technique, several other features made it an easy decision for the facility to move forward:

Durability & Longevity For Lasting Manhole Rehab

Monoform PLUS™ is designed to restore structural integrity while protecting against ongoing chemical exposure. Corrosion-resistant manhole liners help facilities avoid recurring damage, reduce maintenance costs and extend the lifespan of their infrastructure. This approach pairs an ABS plastic interior forming system with an integrated AGRU Sure-Grip® HDPE liner, creating a structurally reinforced, corrosion-resistant barrier that enhances durability and long-term performance.

Withstands Extreme Temperatures

In addition to its corrosion-resistant properties, HDPE can withstand very high temperatures up to 180°F. Other manhole linings aren’t compatible with extreme temperatures, but Monoform PLUS™ can take the heat.

Fast & Cost-Effective Installation

HK Solutions Group’s Monoform PLUS™ technique combines structural trenchless repair and corrosion protection into one efficient installation, reducing time onsite, minimizing disruption and delivering a more cost-effective manhole rehabilitation solution.

Achieving Exceptional Concrete Corrosion Repair Results

Our team of manhole rehabilitation technicians spent a total of 24-48 hours onsite for this project, completing the Monoform PLUS™ manhole lining process without disrupting the facility’s operations. Monoform PLUS™ cost the customer only a fraction of what they would have paid for a traditional manhole replacement, not to mention the cost savings of keeping the plant operating the whole time and maintaining the current infrastructure. They were beyond satisfied with the results and are planning to work with HK for Monoform PLUS™ to resolve future concrete corrosion repair needs.

Partner With HK Solutions Group For Innovative Manhole Rehabilitation Solutions

HK Solutions Group provides industrial and municipal services to companies and communities across the country. Our industrial solutions include hydroblasting, industrial vacuum truck services, silo cleaning, dry ice blasting and more, along with our trenchless manhole rehabilitation and underground infrastructure expertise. Contact us to learn more about our diverse range of services or to get started with corrosion-resistant manhole lining solutions today.

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