Scottish Water recommend that soup, gravy, sauce, oil & grease should never be disposed to sewer, further more it is an offence under the Sewerage (Scotland) Act 1968 to dispose of fat, grease or oil down your sink. http://www.scottishwater.co.uk/you-and-your-home/your-home/keep-the-water-cycle-running-smoothly/in-the-kitchen
Recommended best practice is:
- Fat, oil and grease - leave to cool and then scrape into a sealable container and put it in a food waste bin (if available) or general waste bin.
- Give plates, pots, utensils and containers a quick scrape or wipe with some kitchen towel before washing and use a sink strainer in the plughole to catch any bits of leftover food going down the sink*.
- Soup, stocks, sauces and milk products all contain fat, which can also congeal and harden in your drains - leave these to cool/harden, scrape into a container and put them in a food waste bin (if available) or general waste bin*.
- Peelings - put any waste food and peelings into your food waste bin (if available) or general waste bin*.
* check with your local Council/waste contractor for info on how to dispose of used fat, oil and grease.
The requirement to recycle food waste does not apply to liquids. Thick soups may be strained to capture food waste suitable for collection & treatment as advised by the collection agent. Thin soups, gravy, sauces etc. that cannot be accepted by food waste collection services should be dealt with using Scottish Water guidance above.