While on a walking tour with foreign ramblers, we stopped at Wied il-Mielaħ to view the arch and I was explaining beforehand that sewage no longer flows here and is now being redirected to the sewage treatment plant.
I should not have spoken so soon... We were welcomed by sewage smells, the sounds of fluid flowing beneath the steps and the end result was a grey sea that was certainly anything but clean.
I wrote to the local council and also to Water Services Corporation about this state of affairs in May but no feedback has been forthcoming.