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One of the biggest challenges facing municipalities across the country is the maintenance of the hundreds of thousands of miles of public sewer lines and the lateral lines that connect private residences to the public sewage system. According to the U.S. Environmental Protection Agency (EPA), there are between 23,000 and 75,000 sewer overflow events every year, most of them caused by deteriorating infrastructure. Local governments are expected to invest billions in repairing these wastewater assets, forcing civic planners to seek out cost-effective solutions that will allow them to deliver the most value with their limited budgets.

What You Need to Know About Manhole Deterioration

As the gateway to the country’s sewer systems, manholes are particularly vulnerable to deterioration over time. In addition to being used as access points, they’re also subjected to a biochemical process known as Microbial Induced Corrosion (MIC). This complex chemical reaction occurs when hydrogen sulfide gas produced by wastewater bacteria interacts with the natural properties of concrete to create sulfuric acid, which can rapidly corrode a manhole’s structural integrity. As these structures deteriorate, they increase the risk of groundwater leakages, sewer line blockages, and sewage gas leaks. More importantly, they become more susceptible to additional damage in the form of root intrusion and shifting soil.

Manholes have been utilized as access points for more than 200 years. Until the mid-20th century, they were mainly built using brick and mortar. Since the 1950s, most of them have consisted of precast concrete, which usually had an expected service life of 50 to 60 years. That means that a large number of manholes across the country are beginning to deteriorate and fail. Even worse, the removal of toxic heavy metals such as lead, chromium, mercury, and arsenic from wastewater as part of the 1980 Clean Water Act created a more favorable environment for bacteria, which accelerated structural corrosion and shortened the service life of many manholes.

What is Manhole Rehabilitation?

While modern manhole manufacturers have developed structures that are much more resistant to the impact of MIC, wholesale manhole replacement is simply too expensive for many municipalities. Manhole rehabilitation, on the other hand, offers a cost-effective solution that addresses the immediate needs of deteriorating infrastructure and greatly extends the service life of existing sewer systems.

The process of manhole rehabilitation involves the application of polymer coatings or cast-in-place liners to reinforce the structural integrity of the manhole. After the manhole surface has been prepared by washing away debris with a high-pressure hose, spray-applied polyurethane lining is used to reinstate structural integrity and provide chemical resistance. The rehabilitation process can extend the service life of a manhole by as much as 50 years and can be performed quickly with minimal disruption to the community.

3 Benefits of Sprayroq’s SprayWall Structural Polyurethane


For nearly three decades, Sprayroq has been one of the most innovative names in trenchless technology solutions. Their flagship product, SprayWall, is a leading manhole rehabilitation solution trusted by customers around the world. A self-priming, spray-applied polyurethane lining, SprayWall can be applied in varying thicknesses and needs only 60 minutes to cure enough to accept flow. This quick curing time ensures that a manhole can be returned to service quickly, making it an ideal solution for projects where sewer services cannot be disrupted for a long period of time.


Once applied, SprayWall provides a continuous, corrosion- and abrasion-resistant surface. The interior walls can stand up to substantial abuse, greatly reducing the wear and tear associated with maintenance tasks such as cleaning out the manhole with a vacuum truck tube. Even if tools or equipment are accidentally dropped down the manhole, the urethane coating will easily withstand the impact without compromising the structure.


Designed to add another 50 years of service life to manhole structures, SprayWall has undergone extensive testing to ensure it meets environmental and safety standards. In addition to being 100% VOC-free, it is NSF 61 approved and has proven resistant to a wide variety of chemicals. Easily and quickly applied by a certified technician, SprayWall is one of the most effective and practical solutions for manhole rehabilitation.


While cement may appear to be a more affordable option upfront, the ongoing costs of maintenance and its shorter lifespan ultimately make it a less economical choice. With SprayWall's exceptional durability and minimal upkeep needs, it stands out as a cost-effective solution in the long run. Furthermore, SprayWall outperforms cement in typical water and wastewater conditions, making it a more dependable choice for crucial infrastructure projects. 

Contact Express for Cost-Effective Manhole Rehabilitation

At Express Sewer & Drain, we’re proud to be a Sprayroq Certified Partner (SCP), which allows us to offer fast and effective manhole rehabilitation services throughout the Sacramento area. As a longtime advocate of trenchless technology solutions, we see Sprayroq as a natural partner in our mission to resolve serious challenges to municipal sewer lines without disrupting local infrastructures or incurring unnecessary costs associated with digging up city streets. SprayWall structural polyurethane allows us to provide environmentally sound, durable, and cost-effective solutions when it comes to manhole rehabilitation.

To learn more about how Sprayroq products can bring your latest municipal sewer project under budget, contact the team at Express Sewer & Drain today.


Topics: Trenchless Technology