Sewage treatment plants use colonies of live natural micro-organisms to break down pollutants in domestic sewage. Many chemicals found in the household can inhibit or kill these micro-organisms, particularly if used in excessive amounts.
Bear in mind that treatment plants serving a few houses do not have the benefit of dilution that occurs at a large sewage works. A bottle of bleach tipped down the toilet in Birmingham would be virtually lost amongst the millions of gallons of sewage arriving at city’s treatment works; a bottle of bleach in a plant serving half a dozen houses could be a lethal dose.
If the micro-organisms are damaged, the will usually recover in time. But in the meanwhile one of the more obvious symptoms is an unpleasant smell, so it is in residents’ interests to avoid this.
Generally speaking, all common household cleaning fluids are acceptable to use, providing they are used in accordance with the maker’s instructions and stipulated concentrations.
The following are some of the most common chemicals found in household situations. It is not an exhaustive list and the golden rule should always be ‘if in doubt, leave it out’.
Bear in mind also that it isn’t only the toilet that is connected to the treatment plant; anything that goes down the sink, bath etc. also ends up there.
Washing machine and dishwasher detergents, washing-up liquids
Perfectly all right in normal concentrations and usage. Problems can occur if, for instance, you are washing the jerseys of the local rugby club’s five teams! Excessive amounts of biological detergent can affect the biomass development.
The BioDisc incorporates a unique flow management system which enhances its ability to handle shock loads of detergent waste, but there are limits even to this, so if you have to do unusual amounts of clothes washing it would be a good idea to spread it over a few days.
Floor cleaners, disinfectants and bleaches
These are safe to use in accordance with the maker’s recommendations and in the minimum necessary concentration. Do not pour neat disinfectant or bleach down the sink or outside gullies. If these are smelly it usually indicates a build-up of decaying material or a plumbing problem and should be dealt with accordingly.
Nappy disinfectants and bottle sterilising fluids e.g. Milton
When disposing of the used fluid, ensure that it is well diluted with water. The easiest way of doing this is usually to flush it away down the toilet.
Waste disposal units
These do not inhabit the micro-organisms, but depending on use, they can present the treatment plant with considerable extra load. It is much better to compost your vegetable peelings etc. as it’s much cheaper and more environmentally-friendly.
Home beer and wine making
This presents a similar problem to waste disposal units. The treatment plant has to work as hard to treat one pint of beer tipped down the drain as it does to treat all the normal waste produced by one person in 24 hours. See also the notes above regarding bottle sterilising fluids
THE FOLLOWING MUST NOT BE DISCHARGED INTO THE DRAINS
- Motor oil, grease, anti-freeze, brake fluid etc.
- Cooking oil and fat
- Weed-killer, insecticides, fungicides and other gardening chemicals
- Paint, thinners, white spirit, turpentine, creosote etc.
- Medicines – take unused medicines to a pharmacist for safe disposal
- Photographic developing fluids
- Nappies, sanitary towels, rags, soft toys, tennis balls etc. – it’s amazing what gets flushed down the loo from time to time! Although such items are not directly damaging to the micro-organisms they can cause problems, not the least of which is simple blockage of the drains. Even so-called ‘disposable’ nappies and sanitary towels often do not degrade fully in the treatment plant and can lead to malfunction, so it is best to dispose of them by other means.
Routine de-sludging and servicing
These are vital to the plant’s ongoing operation and should be carried out in accordance with the guidelines in the owner’s handbook.
Our team of engineers are fully qualified and experienced in servicing and maintenance of your sewage treatment system. Call us for a quote on 01388 537030.