Manhole Device Technology
Stop paying to treat rainwater.
Reduce inflow at the cover. Vent safely.
Solves Both Problems Simply & Economically.
Our technology: Sealed holes + valve-reduced inflow limit rain entry.
Well‑ventilated gases prevent corrosive buildup and safety risks. Sewer Sentry replaces the cover with a patented system that reduces inflow while still venting H₂S safely.
Available in both Cast Iron and Composite manhold covers.
Available in the following manhole lid sizes: 24 Inch, 26 Inch, 32 Inch.
Available in 4-inch and 7-inch heights.
The Sewer Sentry riser is available in Nylon 66 and Stainless.
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.
US Patent 8,851,781 B1
Manhole Device
Prevent rainwater from entering manholes with the Sewer Sentry System, a patented technology designed to reduce inflow during storms and protect sewer systems from corrosive gases. The innovative design features a riser with a ball check valve that prevents backups and costly stormwater treatment, while allowing harmful gases to safely vent. Compression-tested and DOTD-approved, the Sewer Sentry ensures durability and reliability.
How it works?
The Sewer Sentry device stops storm water from going through hole in the manhole cover simply by creating a new point of entry ―a “raised hole”―that is 5/8” higher than the surface of the manhole. At the same time, it reduces sewer gas problems, by allowing enough oxygen to reach the sewer.
With a standard manhole, heavy rain inflow leads to more water in the storm drain and sewer that needs to be processed thus overwhelming the pumps.
With the Sewer Sentry manhole, the rain water is correctly diverted to the storm drain, allowing the system to breathe properly and not overwhelming the pumps.
Available in both Cast Iron and Composite manhold covers.
Available in the following manhole lid sizes: 24 Inch, 26 Inch, 32 Inch.
Available in 4-inch and 7-inch heights.
The Sewer Sentry riser is available in Nylon 66 and Stainless.
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.
US Patent 8,851,781 B1
Venting
Abstract: Evaluation of Sulfide Control by Air-Injection in Sewer Force Mains: Field and Laboratory Study
Introducing oxygen into sewer systems can effectively reduce hydrogen sulfide (H₂S) levels by creating aerobic conditions that inhibit the activity of sulfate-reducing bacteria responsible for H₂S production. This approach has been successfully implemented in various cases. For instance, in Milford, Connecticut, an oxygen injection system was installed to address severe sewer collapse and high H₂S concentrations exceeding 50 ppm in lift stations. The implementation of this system led to the elimination of H₂S-related issues.
Example of cost to implement for a 1MGD System:
Capital Cost: $150K-500K
Oxygen Supply: $5K-8K
Energy & Maintenance $10K-20K
H₂S is one of the most damaging and costly byproducts in wastewater collection systems.
Left unmanaged, H₂S leads to chemical and structural deterioration, public complaints, and safety risks.
Cover Seizing
This option requires no roadway construction and can be installed in as little as 30 minutes!
Sentry Retrofit requires utilizes existing frame with drop in gasket and new Sewer Sentry Cover. Minimal traffic disruptions, no permits needed.
What are the benefits of Sewer Sentry?
Sewer Sentry replaces the cover with a patented system that reduces inflow while still venting H₂S safely.
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.
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.
The Sewer Sentry Manhole Device is Department of Transportation and Development Approved, ensuring reliability and safety for municipal systems. It has been compression tested to ASTM D4280-12 standards, successfully withstanding 6000 lbs of pressure in three directions without cracking or deformation, demonstrating its durability for public infrastructure use.
- Compression Tested
- Tested ASTM D4280-12
- 6000 lbs 3 ways; no cracking or deformation
Installation
The Sewer Sentry manhole is designed for easy installation, making it a popular choice for over 26 cities that are already benefiting from its reliable performance. Cities that have implemented this solution are enjoying improved sewer inflow management, reducing flooding risks, and lowering maintenance costs.
Cities are seeing tremendous results!
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!
Ready to reduce Your City's Sewer Inflow?
Frequently Asked Questions
We’ve gathered answers to the most common questions we receive about Sewer Sentry. Click on any question below to explore more and discover how our solutions can help improve your wastewater system.
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
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.
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.
The Sewer Sentry Manhole Device is Department of Transportation and Development Approved, ensuring reliability and safety for municipal systems. It has been compression tested to ASTM D4280-12 standards, successfully withstanding 6000 lbs of pressure in three directions without cracking or deformation, demonstrating its durability for public infrastructure use.
- Compression Tested
- Tested ASTM D4280-12
- 6000 lbs 3 ways; no cracking or deformation