Thanks for that magicniner.

My only issue now is finding out who to speak to!
Where I stay just now, we're essentially off-grid in terms of sewage, using ye olde septic tank and effluent run-off into the local river, so not sure if it'll fall under Scottish Water or SEPA juristiction.
Given how little I'm likely to use, commercial disposal when the need arises may be a cheaper option than any licence fees to the above...