Man holding noise

From time to time, we have all had the displeasure of smelling “sewer gas.” We know it when we smell it but we may not be aware of what it is, what it means and what we need to do about it – especially if we smell it in our homes or businesses.

Sewer gas is that rotten egg smell that is produced by the sewage system. It is the result of the decomposition of waste materials. The gasses are a mixture of methane, hydrogen sulfide, ammonia and other chemicals and they are more than “just unpleasant” to smell. Even at low levels, the gases can irritate your eyes, make you cough or produce dizziness. Higher levels are very serious and they can pose a serious health risk and in some cases they can cause fires or explosions.

If you have this smell in your home or your business, please call a plumber as soon as possible because this constitutes an emergency.

What causes sewage gas?

Chances are if you smell sewage gas, you will usually smell it in the basement. Sewage gas is heavier than atmospheric gas and it “sinks” to the lowest level in the house or in a room. The sewage gas smells are caused because somewhere within or outside of the house, the rotten egg smell is not being vented and so it starts to accumulate. The following are some of its causes.

Toilet rings

The first thing a plumber will look for is the easiest to fix; a worn wax ring under the toilet. When the seal under your toilet becomes faulty, there can be a poor fitting and leaks. Tell-tale warning signs include small leaks at the base of the toilet or the toilet itself “rocking.”

 

Sewer vent pipes

Some basic things have not changed very much in the building of homes. When building a home, a vent pipe is put in allows the rotten egg gases to vent from the drainage system to the outside and obviously allows outside air into the system.

If for any reason, there is a block at any point in the pipe, there can be a buildup of the gas. If your bathroom sink, shower or bathroom toilet waste lines vent gases into this pipe and there is a clog or block, a vacuum can occur every time a toilet is flushed or water is drained. This vacuum will pull sewage gasses from the system out into your home.

Blocked air vent/Blocked drains

In many cases, the air vent may be clogged; it could be something as simple as a bird’s nest or a beehive. In any case if the problem is not remedied, a gas build-up can occur. There can also be an odor build-up where in spare bathrooms and showers the drains have not been in use. When a drain dries out, a clog can occur. This can also cause a gas smell.

More serious problems

If none of the problems above are found more serious problems may be to blame. The problem may be in the plumbing of the drain lines or vent lines such as serious cracks. Plumbers may put pressure along the line to determine the point of the break.

There may also be a structural problem stemming from poor building construction. Sometimes the builders place the furnace or air conditioning return air ducts too close to the vent pipes and the sewage gasses are brought in that way.

Finally, there may be a break in the foundation of the house. This may possibly allow gasses from sewage lines or septic fields to enter into the basement.

No matter the reason for the noxious odor, it must be immediately addressed.