Septic tank odours can be disarming, to say the least, and can and will linger until they are addressed; a quick spray with a deodoriser will most likely not eliminate the problem. Odours from a septic tank arise as the result of many different causes, and can emanate from both inside and outside the home. This may require implementing one or more odour-fighting solutions to rid your home of the odour problem in its entirety.
Indoor Septic Odors
Removing indoor septic odours can be one of the easiest odours to eradicate. The cause of the odour is often a dry drain, or "trap" in a pipe, usually in a little-used bathroom or sink in the home. The reason a dry trap causes an odour is the pipe is designed in a "U" shape to trap the amount of gases and odour that come back up through the pipes. This simple design works because it will generally have water that sits in the U-shaped trap area of the pipe. However, particularly in less-used plumbing in the home, these traps can dry out, leaving no barrier between the drain and the odour. The fix is to simply run water down the drain, and make certain to do so periodically to avoid future odour problems.
Septic Cleaning Products
Cleaning and flushing out the lines between the septic tank and the home can help to eliminate septic tank odour. Similar to traditional plumbing products, flushing these products through the septic lines may be enough to eliminate the odour. Call your local home improvement store that sells septic tank maintenance supplies or research online to find odour-fighting products.
Extending the septic tank vent stack on the top of the roof is a relatively quick and easy means of eliminating many outdoor odours. The septic vent stacks often do not extend high enough to allow the breeze to safely blow away the septic tank odour. Rather, it is blown back down toward the front or rear of the home, bringing septic tank odour with it. This odour can often be mitigated by simply using a PVC pipe to extend the vent stack to about three feet high. There are also charcoal filters that can be placed over the vent stack, filtering the odours before they are wind-borne.
Other Causes of Odors: Indoors and Outdoors
Pouring coffee grinds and oils down the garbage disposal will eventually cause a backup of the septic lines, bringing odours back up along with clogged materials. Outside, allowing water to collect and pool around the septic tank area can cause damage to the tank, and the moisture may facilitate septic tank odours. Also, you should not plant trees around the septic tank area, although grasses and small shrubbery is generally fine, as the roots can cause damage to the tank and line, resulting in odours and the need for repair.
Calling a professional may be necessary if nothing else has worked. It is possible the septic tank, particularly if it is old or has not been maintained properly, requires a thorough cleaning and flushing of the septic lines. If this is required, make certain to contract with a professional familiar with both plumbing and septic tanks, not simply one or the other. This way you are more likely to address either a tank or a plumbing situation (perhaps both), by the same person during the same maintenance call.