Discharge to the sea or an estuary
Mean low water spring mark
If you are discharging to the sea or an estuary, you must discharge below the Mean Low Water Spring (MLWS) mark. The MLWS mark is how far the sea goes out at low tide. The lowest point a tide will normally reach is marked on an Ordnance Survey (OS) map as MLWS. You can access maps using our NGR Tool. To see the MLWS you must click the "Zoom to OS 1:25,000 map" button.
If you can't discharge below MLWS, you should contact us by emailing the Water Permitting Team.
The outfall for your discharge should have protection against erosion of the underlying sand to prevent movement of the outfall pipe and leakage of effluent above MLWS.
Engineering works below Mean High Water Spring (MHWS), such as the construction of a sewage outfall, may require a licence from Marine Scotland.
Bathing waters and shellfish waters
If your discharge is near a bathing or shellfish water, you will normally need to treat the sewage to reduce the bacteria before it is discharged. Our online registration service will work out if your discharge is near a bathing or shellfish water.
If the service indicates that your discharge point is near a shellfish harvesting area, you should contact us by emailing the Water Permitting Team.
Our staff will carry out further assessment to determine if enhanced treatment is requires.
You can then apply for a registration to discharge by completing an application form and emailing it to our Registry Team.
There are various treatment options to reduce bacteria including installing a package treatment plant or a septic tank in conjunction with a proprietary filtration system that uses bio-fibrous material. For example, the bio-fibrous material could be coir or a peat-free substitute.