The Manhole Odor Eliminator is a carbon filter system designed to remove odors from sewer vents, grease traps, combined sewer stormwater systems, storm drains and other vented manholes. Each filter cartridge contains activated carbon filter media. This filter media can remove large amounts of hydrogen sulfide and other odors from sewer manholes. The Manhole Odor Eliminator is a complete odor control filter system.
The Manhole Odor Eliminator
Basic Problem
Sewer gases escape from manhole covers and cause nuisance, health and safety problems. The ambient air flow into manholes and the sewer gases flow out of manholes is caused by many factors including sewer system design, operation, time, chemical and biological, environmental and other conditions.
These conditions result in fluctuating pressure and flow of air and gasses through manhole covers. On extensive sewer lines with multiple manholes only some of the manholes may have severe odor problems.
Sewer odors
Harmful hydrogen sulfide and other gasses
Complaints from residents and businesses
Common Solution - Prior Art
A pre-formed insert is fitted under the manhole cover and an odor absorbing media treats sewer gases before exiting manhole cover.
This is considered an improvement in reducing odor complaints. The problem with this method is a short cartridge life, high cost of cartridge replacement and service. Health and safety issues from hydrogen sulfide and other gasses occur during each service along with disruption of traffic in the service area.
Short filter life
High maintenance cost
Limited effectiveness
The Manhole Odor Eliminator is designed so that contaminated air enters the filter through a hole in the bottom of the cartridge. Air is then dispersed through activated carbon before exiting the filter. The manhole odor eliminator is equipped with an air bladder. The bladder buffers the frequent fluctuations of sewer gas. The odor absorbent carbon only has to treat the peak flow rates. The filter cartridge is supported by either a plastic or stainless steel frame.
Introducing The Manhole Odor Eliminator
The Manhole Odor Eliminator is the latest patented sewer odor treatment method. This engineered device is considered a substantial improvement over prior art.
This product includes many of the prior art items and features plus a variable volume device (bladder) that acts to accommodate the frequent fluctuations of pressure and flow that affects sewer gases and ambient air flow in sewer systems.
The expansion and contraction of air and gases from thermal temperature changes and plumbing cause flow in or out of the manhole. The bladder captures a portion of this flow and only the flow exceeding the bladder capacity allows sewer gas to pass through the cartridge and exit the manhole. This feature substantially extends the life of the activated carbon filter cartridge many times.
Long filter life
Low maintenance cost
Higher efficiency
Grease Trap Filters
The Manhole Odor Eliminator is very good at eliminating the odors from grease traps. Shallow grease traps can be fitted with a customized unit.
Manhole Odor Eliminators also work well in septic systems, sand-oil interceptors, fountain water storage and other underground vaults. Custom support frames can be made to fit round, rectangular or any other shaped manhole cover.
Fits shallow manholes
Works in many different environments
Customizable
Combined Sewer Stormwater System
The Manhole Odor Eliminator also works in storm drain catch basins in both stormwater systems and in combined sewer stormwater systems. The combined system uses the same activated carbon filter cartridge and bladder as the standard Manhole Odor Eliminator®. The stormwater bypass allows water to flow through the system while still sealing the gases in the storm drain. Combined sewer stormwater filters are also fitted with a rain deflector cover to prevent saturation of the carbon filter cartridge.
Note: Inventor of the Manhole Odor Eliminator has several other bladder-related patents and patents pending for solutions to other environmental and equipment problems. Click here to visit the Inventive Resources, Inc. website.
Participate in a Study
We are currently testing manholes for hydrogen sulfide gas concentrations. Contact us for more information on having your location included in our study.
FAQs
What is sewer gas?
Sewer gas—at least the kind that causes odor problems in homes—is a mixture of inorganic gases produced by anaerobic (oxygen-free) bacteria breaking down sewage and sludge. This mix can include hydrogen sulfide, ammonia, carbon dioxide, methane, nitrogen, and hydrogen.
Why does it smell so bad?
Hydrogen sulfide is almost always the main culprit behind the foul odor. Ammonia may contribute in rare cases, but the other gases are odorless. The human nose can detect hydrogen sulfide at incredibly low concentrations—between 0.001 and 0.01 parts per million (ppm). To visualize and put it into perspective: 1 ppm is like one inch in 15.8 miles. It often smells like rotten eggs due to hydrogen sulfide. Some people also describe a metallic or musty odor.
My neighborhood is smelly, how can I solve the sewer odor in my neighborhood?
Municipal sewer odors in neighborhoods are typically caused by hydrogen sulfide and other gases from decomposing waste, especially in aging or overloaded infrastructure. Residents can help by reporting odors and maintaining private plumbing within their own property. It is important to report odors to your local public works or wastewater department. Odor complaints help pinpoint problem areas and trigger inspections and possible repairs. Support microbial treatments, biofilters and activated carbon systems like the MOE® help neutralize and or decrease hydrogen sulfide at the source.
How is the MOE® installed compared to a standard manhole odor filter? Does it require special tools or skills?
Installing The MOE® is simple and requires only basic tools—such as a manhole pick, hand shovel, wire brush, gloves, broom, and a trash bag.
Replacing a manhole odor filter cartridge is a straightforward process that doesn’t require specialized tools or advanced training. Typically, one person can complete the installation by:
Removing the manhole cover
Disposing of the spent filter
Placing the new cartridge in the designated position
Replacing the manhole cover securely
The entire process is quick, minimizes disruption, and helps maintain effective odor control with minimal effort.
How does the design of The MOE®’s odor filter insert ensure it does not interfere with normal manhole cover operations?
One of the standout design features of the odor filter insert is its ability to remain out of sight once installed. The filter nestles securely onto the rim of the manhole frame, sitting just beneath the cover itself. This placement means the filter is effectively hidden from view, and there’s no added hardware visible from the roadway. This low-profile design allows routine activities to go on as usual. In short, this passive treatment filter quietly does its job without getting in anyone’s way, out of sight, out of mind (and nose), while the integrity and daily operations of the manhole remain mostly unaffected.
What is the procedure for ordering a custom MOE® Manhole Odor Eliminator? What documentation is required
Ordering a custom Manhole Odor Eliminator is a simple process designed to ensure a precise fit for your specific application. Because each unit is tailored to the unique dimensions of your manhole, accurate measurements are essential.
To get started:
Visit our Get a Quote page and complete the sizing guide form.
Use the included measurement guide to record key dimensions directly at the job site. (link to sizing guides)
Watch our sizing guide video for step-by-step visual instructions (linked on the form).
Once your measurements are complete, return to the ordering page and submit your information. Our team will follow up with the next steps to finalize your order.
How does sewer gas enter a house?
Sewer gas only enters a home when there’s a problem with the plumbing. The most common issue is untrapped drains—especially in basements or utility rooms. In most of the United States, homes built after 1970, because of the widely availability of PVC, P-traps because more used, but older homes not as likely. Currently, plumbing codes continue to require properly vented P-traps on all fixtures and mandate replacement of older or outdated traps during renovations and repairs. Dry or broken plumbing traps, cracked sewer lines, or blocked vents can allow sewer gas to enter your home.
Other possible entry points include:
Dry traps: If a drain isn’t used often, the water in the trap can evaporate, breaking the seal.
Damaged traps: Cracks can let water escape, eliminating the seal.
Broken drain lines: Cracks between the trap and main sewer allow gases to leak—and possibly sewage to accumulate in crawlspaces or basements.
Faulty or blocked vents: Plumbing vents equalize pressure and release gases outside. If blocked or improperly installed, they can siphon water from traps or leak gases indoors.
How can persistent sewer odors from manhole covers negatively impact cities, industries, and nearby residents?
Sewer gases can escape from manhole covers, causing nuisance and possibly creating health and safety problems. Hydrogen sulfide (H₂S) based sewer odors can be an extreme nuisance for residential homeowners and users of public spaces or properties nearby to a smelly manhole. Persistent nuisance sewer odor complaints often lead to negative publicity and ongoing headaches for cities or industries managing the infrastructure. These recurring issues not only drain time and resources but also are crucial factors in maintaining public satisfaction and in some cases, regulatory compliance.
Can sewer gas formation be prevented?
In localized trouble spots like treatment plants or lift stations, oxidizers (e.g., oxygen, hydrogen peroxide, chlorine, permanganates) can be added to boost oxidation and reduce H₂S formation.
In the sewer collection system, flushing the lines to increase flow and remove sediment can help—but it’s only practical for short-term fixes, not ongoing prevention.
Can sewer gas come through my HVAC system?
Yes. If your furnace or HVAC system is near a faulty drain or vent, it can circulate sewer odors throughout your home.
What makes the MOE® different from other odor control systems?
The MOE® includes a variable volume bladder that buffers pressure and flow fluctuations, extending filter life, and improves performance. There is no other product like ours! The MOE® is a passive odor eliminator is a device that uses natural airflow to continuously disperse odor-neutralizing or fragranced molecules into the air without needing a fan, batteries, or electricity. These systems are designed for smaller, localized areas and work by using a cartridge or gel that releases its contents slowly over time, often for weeks or month
What type of activated carbon is used in The MOE®’s odor filter inserts and what are its safety features?
Our odor filter inserts feature activated carbon like most others. This specialized carbon is engineered to effectively capture and neutralize hydrogen sulfide and other unpleasant gases commonly found in sewer environments. What really sets The MOE® apart from other manhole odor inserts is our patented bladder system that allows sewer gases to disperse through the carbon slowly, even at peak flow times, extending the life of the filter media while keeping the streets stink-free.
When it comes to maintenance, replacement filters are available to ensure continued performance. These replacements drop into the housing quickly and easily. This makes routine filter replacement safer for workers and minimizes regulatory concerns.
What measurements will be needed when ordering The MOE®?
To ensure a perfect fit, a few specific measurements are needed before we can fabricate your custom manhole odor filter insert:
Width and Depth of the Drop Ring: If your manhole cover includes a drop ring (the portion extending below the lid), measure its width and depth. If your lid is completely flat with nothing extending below.
Opening Dimensions: Accurately measure both the outside diameter and inside diameter of the manhole opening (not just the lid). For covers with a drop ring, ensure that the width of the drop ring does not exceed the inside diameter of the manhole.
Note any obstructions such as ladder rungs or changes in the dimensions within the manhole that may may impact a proper fit. Remember the MOE® fits inside the sewer manhole so it needs some clearance.
These measurements help us tailor the manhole odor eliminator filter to your unique requirements, ensuring a snug and secure fit. For more detailed measurement information, please refer to your sizing guide. Double-check all measurements before sending your specifications to ensure a smooth experience.
What is a trap?
A trap is a U-shaped section of pipe, tubing, or tile that holds wastewater. This water acts as a barrier, preventing sewer gases from escaping through the drain.
Can sewer gas harm people?
Only in extremely rare situations. While hydrogen sulfide is toxic, the concentrations found in homes with odor issues are far below harmful levels. Toxic effects on the central nervous system occur at concentrations above 150 ppm—15,000 to 150,000 times higher than what most people can smell. However, entering confined spaces like tunnels or deep holes with active sewage breakdown could pose a serious risk, hence warnings like confined space permit requirements. Sewer gas can contain hydrogen sulfide, methane, ammonia, and other toxic compounds. Exposure may cause headaches, nausea, dizziness, or even more serious health effects in high concentrations. The CDC has Immediately Dangerous To Life or Health (IDLH) values posted on their website for many chemicals, if you are curious the link is: https://www.cdc.gov/niosh/idlh/intridl4.html
How can I keep sewer odors out of my house?
The best solution is to identify and fix plumbing issues. If your floor drains lack traps, have them installed. Avoid plugging the drain entirely—this could lead to flooding. A licensed plumber can assess your system and recommend tailored repairs.
Is sewer gas more common in certain areas of the house?
Yes. Bathrooms, basements, laundry rooms, and kitchens are common entry points due to their plumbing fixtures.
How does the MOE® help reduce odors?
It uses a proprietary blend of media inside a replaceable filter cartridge to absorb hydrogen sulfide (H₂S) and other sewer gases, effectively neutralizing the “rotten egg” smell. Peak gases will go through the variable volume bladder and through the filter cartridge. The filter cartridge will scrub the gas and reduce/eliminate odors.
Are replacement cartridges available for The MOE® filters through your website?
Yes! For ongoing odor control, replacement cartridges for The MOE® filters are available directly from us—the manufacturer. To place an order, simply email us at info@iriproducts.com or call 209-545-1663.
To keep your odor control system operating at peak performance, we recommend replacing the filter cartridge approximately every 12 months, depending on flow levels. If you notice any odor issues, consider replacing the cartridge sooner.
Does the MOE® work year-round?
Yes, but it’s especially effective during hot weather, when odor issues are most severe due to increased gas volatility.
What is the lead time for the MOE®?
Once you submit a sizing guide and approve the dimensions, the lead time is 2 weeks approximately.
How can I tell if my floor drains are trapped?
Pour at least two gallons of water into the drain and look inside. If water remains standing and fills the pipe, the drain is likely trapped. Check again after a few hours—if the water is gone, the trap may be dry or missing.
If odors persist, pour water into the drain and check again in an hour. Lingering smells likely mean there’s no trap.
How is sewer gas produced?
Hydrogen sulfide (H₂S) forms when sulfate (SO₄) is reduced to H₂S and water in oxygen-free environments. It typically takes two to three days to form in wastewater—by which time it’s usually at or past the treatment plant.
However, H₂S can form in:
Slime layers inside sewer pipes below the water line.
Settled sludge at the bottom of pipes.
Stagnant sewage caused by blockages or slow flow, which lowers oxygen levels.
All sewage systems produce sewer gas at some point.
Can sewer gas cause explosions or fires?
Methane in sewer gas is flammable. In enclosed spaces with poor ventilation, it can pose a fire or explosion risk.
What is passive odor treatment?
The MOE®manhole odor eliminator is a passive odor treatment device that uses natural airflow to continuously disperse odor-neutralizing through a filter cartridge without needing a fan, batteries, or electricity. The MOE® system is ideal for localized problem areas
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