Ok I visited this place a while back. Its located at Forenss at Palm Bay.

Currently still in use this was a live site when explored. It is owned by Sothern Water and used to treat waste water before sending it out to sea via outfall pipes.

We were amazed at the size of this place, its huge and on two underground levels. As we walked through the plant we could see and hear all the machinery working away and were amazed to find there were no active alarms, cameras or security. All the electrics were working and the lights were on making it a great place to photograph. This was built and extended as part of the Thanet waste water treatment programme.