Sewer Sentry System

Sewer Sentry System


Sewer Sentry is a sewer solution system that dramatically reduces inflow during rainstorms and lowers a sewer system’s exposure to corrosive gases, which can cause odor and become an explosive hazard. The Sewer Sentry sewer hole cover works as a manhole cover gasket and manhole ventilation system. This manhole vent seals manhole covers with a proprietary device. The Sewer Sentry device is constructed of Dupont Zytel, a nylon resin that is impact-resistant, chemical-resistant, UV light-resistant, heat-resistant, and cold-resistant. It is also available in stainless steel.

Additional Specifications

All Sewer Sentry manhole cover gaskets are fitted with a 1” wide, 1/8” rubber seal that helps create minimal leakage between the sewer hole cover and bearing surface. The Sewer Sentry sewer solution system is installed through a hole that is drilled in the manhole cover using a rubber gasket to minimize leakage. It protrudes approximately 5/8” above the surface of the manhole cover, allowing some sheet flow over the cover but not high enough to damage bicycles, vehicles, etc.

The Sewer Sentry Manhole Vent Device was independently tested for compression strength with a minimum 6000 lbs. with no cracking or deformation. Sewer Sentry is offered in stainless steel, and DuPontTM Zytel® ST801-NC010A, a nylon 66 resin that is highly impact-resistant, chemical, UV, and heat/cold resistant. The sewer sentry is installed with a rubber gasket constructed of commercial-grade EPDM (Ethylene Propylene Diene Monomer) blended rubber in 60 durometer (a measure of hardness).

EPDM provides superior properties for outdoor and high-temperature applications, with a minimum of 1000 PSI tensile strength, accommodating temperatures from -20 to 230 degrees F, provides resistance to ozone and many oxidizing chemicals and acids, and is highly resistant to sunlight.



Cast Iron, Composite


24 Inch, 26 Inch, 32 Inch


4 Inch, 7 Inch

Riser Type

Nylon 66, Stainless


Prevent Rainwater From Going Into The Manholes

The Sewer Sentry System is an innovative, patented inflow reduction technology solution that dramatically reduces inflow during rainstorms and lowers a sewer system exposure to corrosive gasses.

Allows Harmful Sewer Gases to Vent

The Sewer Sentry Riser is ⅝” high, so water goes around the vent hole. If the water rises higher, a ball check valve prevents the rainwater from entering the manhole. This eliminates extra electricity and water treatment costs at the pump stations, prevents storm water backups into homes and businesses, and allows harmful odors to escape.

DOTD Approved

Watch The Sewer Sentry in action

Learn how your city could reduce weep hole leaks by up to 98.5% (as tested by Louisiana Tech University)

Frequently Asked Questions

We’ve compiled a list of the questions we get asked the most often. Expand any of the questions below to learn more.

The Sewer Sentry System is an innovative patented solution that replaces traditional manhole rings and covers with specialized ones that prevent rainwater inflow and sewage overflow.

The System dramatically reduces inflow during rainstorms, lowering the sewer system’s exposure to corrosive gases. This efficient management of sewage overflow eliminates unnecessary costs at the pump stations and reduces environmental pollution caused by untreated sewage.

Yes, the Sewer Sentry Riser is designed to allow harmful gases to vent, making it safe. If the water level rises, a ball check valve prevents the rainwater from entering the manhole.

The Sewer Sentry System is available in sizes of 24 Inch, 26 Inch, and 32 Inch, with heights of 4 Inch and 7 Inch.

The System is very durable. It has been compression tested and has met ASTM D4280-12 standards, withstanding 6000 lbs 3 ways without cracking or deformation

Sewer Sentry Cast Iron Ring & Cover
24" Composite Manhole with Nylon 66 Riser

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Don’t just take our word on why you should choose Sewer Sentry. See what our customers have to say about our combined sewer overflow solutions!

Play Video about Sewer Sentry: Testimonial of Recent Sewer Sentry Customer

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