What Are The Pros And Cons Of Manhole Rehabilitation?
Our team at OBIC has decades of experience in sewer system rehab, construction and operation. Our combined experience includes everything from collapsing sewer manholes to deteriorating pipes and everything in between. As a matter of fact, there is not much we haven’t seen, heard and rehabilitated.
While we take pride in our accomplishments and enjoy telling stories of some of the most challenging projects we have tackled, we have also learned a lot over the years. It is that experience and knowledge that helps us to expertly mitigate the varying maintenance challenges facing our clients. Below is a summary of the two most common manhole rehab challenges that our installers face daily.
Manhole rehab challenge #1: inflow & infiltration
The first challenge that has a significant impact on manholes and sewer systems is inflow and infiltration. Although inflow and infiltration commonly begin as a very small annoyance, they can cause damaging structural issues if left unaddressed. For example, long-standing sewer manhole infiltration can cause a cavitation void in the soil surrounding the structure. Eventually, this will result in a potentially catastrophic sinkhole.
While that is an extreme example of challenges caused by inflow and infiltration, a more common one is the effect that they have on system capacity. For example, when clean groundwater infiltrates a deteriorating sewer manhole, it is taken to the water treatment plant. The treatment plant can’t tell the difference between clean groundwater and dirty wastewater, so it is treated as if it were wastewater. This doesn’t sound like a big deal until you begin factoring in the continual increase in operating costs. Eventually, this will also push the plant’s capacity toward its physical and/or permitted limit.
Fortunately, the team at OBIC is well versed in resolving inflow and infiltration challenges. From minor issues to major challenges, our manhole lining system is versatile enough to extend the life of any manhole regardless of construction material, shape or age. Not only can we stop current inflow and infiltration challenges, but we can also offer peace of mind that your sewer system is protected from future issues as well.
Manhole rehab challenge #2: corrosion
Another common manhole rehabilitation challenge is corrosion. Hydrogen sulfide (H2SO4) and microbial-induced corrosion (MIC) eat away at concrete manhole structures or the mortar joint of a brick manholes. Over time, this can cause considerable deterioration. A technical report by USEPA estimates that corrosion causes a minimum deterioration of 1 inch of concrete wall thickness over a 10-year period. This is most likely a conservative estimate largely dependent on varying conditions.
When you do the math, this means that a manhole with a 100-year design life will lose half its original thickness and experience significant structural concerns in only 25 years. Fortunately, OBIC can help with that one too. Our manhole products are designed to be resistant to the corrosive environment found in sewer systems. This allows it to protect the sewer manhole from H2SO4 and MIC structure corrosion, extending the life of the structure by decades.
Many challenges. One solution
There are dozens of challenges facing sewer system owners, too many to cover in one blog post. While these challenges may range in severity, they all have one thing in common. They can all be resolved with OBIC lining systems.
For more information on OBIC’s manhole lining system, or to schedule a free product demonstration, visit OBICProducts.com or call 866-636-4854.