Colorado sewer smoke testing specialists.

Schedule your sewer smoke test today and find dangerous, smelly sewer gas leaks in your plumbing. Click the button or call (303) 944-3794   to speak with an expert at Proactive Sewer & Drain located in Denver.  We server all the way from Colorado Springs to Ft. Collins including all of the Denver metro area.  Same day service may be available.  Both residential and commercial testing.

About us

Specializing in finding the source of sewer gas leaks in your home or business.

Finding the source of sewer gas smells is almost impossible without the proper equipment. Unlike a water leak that shows up, sewer gases drift throughout your property. They may come and go. Less than 1% of plumbers have the proper equipment to quickly pinpoint the source of sewer gas emissions.  Our trained experts are equipped with Hurco Power Smoker II smoke machines. By filling your plumbing drain system with non toxic, white, odorless smoke we can identify the source of sewer gas leaks.

Common questions about sewer gas.

The smell of sewer gas in your home or business is very challenging and very difficult to fix.  Learn how we solve this difficult problem.


We quickly find the source of sewer gases leaking into your home, business or yard using a non toxic, odorless smoke (like a fog machine). We connect to your main sewer line and fill the plumbing pipes with a dense, heavy, odorless fog (it’s called a smoke machine, but it’ll really a fog generator) and you will be able to see exactly where the sewer gasses are leaking into your home or business.

Call us at (303) 944-3794  for a cost estimate or to  schedule a sewer odor smoke test online now!


Sewer gas is a mixture of gases, some toxic, that are present at varying levels. It is formed during the decay of household and industrial waste. Some of the most highly toxic components commonly found in sewer gas are hydrogen sulfide and ammonia. Sewer gas also contains methane, carbon dioxide, sulfur dioxide, and nitrous oxides.


Sewer gas can enter a home through a floor drain, drains or sewer vent lines that may have been penetrated by a nail during construction, vent lines not properly run to the roof, bad studor vents, faulty toilet wax rings, bad seals on a basement lift station, dried out plumbing traps, from a leaking or blocked plumbing roof vent, or (if the gases are in soil adjacent to the house) through cracks in foundations. Sewer gas leaks are actually pretty common.

how can i find the source of my sewer smell?

First, following the odor, try to locate the point of entry, such as basement floor drains or other plumbing fixture locations. Check for a blocked rooftop plumbing gas vent. By adding water to the floor drain or fixtures and/or removing ice/snow/debris from a roof plumbing stack vent, you may be able to prevent sewer gas from entering your home.

It can be very difficult to determine the exact source of the odor. Our sewer gas leak detection service is quick, easy and non invasive. You’ll be amazed to see the non toxic and odorless smoke (fog) seeping from a toilet, behind or a wall or other source of sewer gas. Once the location of the leak is identified by us it’s usually a pretty easy fix for a plumber to repair the problem.

Is sewer gas dangerous to breathe?

The principal risks and effects associated with exposure are:

Hydrogen sulfide poisoning: Exposure to low levels of hydrogen sulfide causes irritation of the eyes and respiratory tract. Other symptoms include nervousness, dizziness, nausea, headache, and drowsiness. This gas smells like rotten eggs, even at extremely low concentrations. Exposure to high concentrations can interfere with the sense of smell, making this warning signal unreliable. At extremely high levels, hydrogen sulfide can cause immediate loss of consciousness and death.

Asphyxiation: High concentrations of methane in enclosed areas can lead to suffocation as large amounts of methane will decrease the amount of oxygen in the air. The effects of oxygen deficiency include headache, nausea, dizziness and unconsciousness. At very low oxygen concentrations (<12%), unconsciousness and death may occur very quickly and without warning.

Sewer gas diffuses and mixes with indoor air, and will be most concentrated where it is entering the home. It can accumulate in basements/crawl space areas. Explosion and fire: Methane and hydrogen sulfide are flammable and highly explosive. Plus your house just kind of stinks.

How can I avoid being exposed to sewer gas?

There are some basic steps that can be taken:

Flush all floor, sink, tub, laundry and shower drains with water one to two times per month to prevent the traps in pipes to the sewer from drying out. All toilets should be flushed as well since these have built in traps in the toilet bowl which can dry out. The water acts as a barrier in the traps to prevent the escape of gases into the home. If you cannot be present, then you should make arrangements for someone to periodically come in and perform this service for you. Occasionally check the roof plumbing vents for blockage from snow/ice or debris such as leaves or bird nests. 

Schedule Now!
Call us at (303) 944-3794  for a cost estimate.


There are dozens of possibilities of what may be causing a sewer smell in your home ranging from wax rings to cracks in a vent pipe. No matter the issue our smoke test is almost guaranteed to find it.

Client testimonials

We do our best to ensure each of our customers receive a thorough smoke test and excellent service!

Don’t breathe dangerous sewer odors. We’ll find the sewer gas leak in your plumbing!

Call us at (303) 944-3794  You’ll speak with a real, local Colorado expert that will help diagnose your issue and determine whether a smoke test will help identify the source of your sewer gas smell.