Why is my septic tank smelling bad?

You may think the smell indicates that the tank is full and needs emptying. This could very well be the case if you are a household of between 4-6 people and it’s been 12 months since your tank was last emptied, however there could be a number of other reasons why you are experiencing this issue which would be worth investigating before you conclude the former: 
 1. The drain field may have failed or tanks may be leaking sewage (in which case you would need a repair specialist)
 2. One of the manholes may not be completely covered or a concrete lid may be broken, or, if a plastic lid, the seal on the lid may be leaking
 3. The aeration tank may not be receiving the appropriate amount of air, which can be caused by a stopped-up air system, broken air lines, clogged air filter or improperly operating air compressor or aerator
 4. Overuse of water, such as washing a lot of laundry in one day 5. Septic odours are being trapped near the ground by high air pressure, especially on a very hot, windless day, or
 7. One of your neighbours has a septic problem and the septic odour is coming from their tank/drain field In any case, it’s always advisable to obtain quotes from professional companies should you feel there’s a problem. If you are unsure how to begin, just put ‘septic tank emptiers’ plus your town into the search engine to get a list of local companies to you, then ask for a couple of quotes to get the best price.