The FOG Problem
"FOG" is an industrial acronym for "F"at, "O"il and "G"rease. "FOG" is the residue from cooking with fat or oil and / or from cooking food containing grease.
The "FOG Problem" is: Sewers are blocked by the "FOG" that householders pour into them.
A build up of fat in the sewer.
- FOG is effectively a sort of "sewer glue", which sticks first to the walls of the pipes and then to anything passing by. That builds into blockages which result in cost, inconvenience and sometimes in sewage overflows.
- FOG has to be regularly removed from pumps and other machinery with shovels and high-pressure hoses to avoid clogging.
- FOG interferes with the bacterial treatment of the sewage.
- Tonnes of FOG have to be sent to the landfill daily, at the expense of the Local Authority and therefore the householder.
- Traces of FOG pass through the system and pollute the sea.
Sources of FOG
FOG comes into the sewers from:
- catering establishments
- food manufacturers
- private houses
How catering establishments and food manufacturers in New Zealand dispose of their FOG residue is controlled by law and checked on by Local Authorities.
There are no legal restrictions on what private houses can put into the sewers.
Stopping FOG going into the sewer is good for the householder and Local Authority.
Stopping FOG going into the septic tank is good for the householder.
Correct disposal of FOG
Fat, Oil and Grease should be caught before they enter the sewer and be put into the rubbish for landfill.
This isn't easy, as FOG is a slippery item to handle under all circumstances. It is understandable that people will be reluctant to mess around storing used fat and oil. This is especially so because it is easiest to handle when it is so hot it can scald you. Cooled fat can be scraped out and dropped in a waste bag but oil is a particularly difficult substance to deal with.
The solution is the Fat Trap, a storage container made for just for this purpose.
Life-cycle of FOG
On its journey to its final resting place, the FOG passes through many places. It goes through the household pipes, then through the sewer pipes under the street, and is finally captured at the treatment plant.
But some FOG is not captured. It escapes to the sea.
This journey is the Life-cycle of FOG.