Waste from roadside rainwater gullies is unfortunately not easy to dispose of. Because it's come off the road, it will be contaminated with oil, so needs to be disposed of properly at a site which can separate out the oil. Facilities which accept this kind of waste are FM Conway in Dartford or CSG in Aylesford.
Sewage from sewer cleans is usually taken to the same places that the cess-pool tankers go, to any one of a number of sewage treatment works. The waste is pumped through a logger which measures the amount of waste you're putting through it. This waste then goes into the works with the normal sewage and is processed.
Sewage Works which take cess-pool waste in the Medway Area are:
Whitewall Creek Works
Ham Hill Works
Aylesford Works.
Other places I go to discharge through cess loggers in Kent are: Tonbridge, Ashford, Canterbury, Wetherlees Hill (between Ramsgate and Sandwich) and New Romney.
For a Pump Station clean, the situation is a little more complex, because pumping stations usually have a large fatberg floating in them. Because the "rag" element of the fatberg will block up a logger, this usually has to go to a specialist facility. Two I use regularly are CFS in Hoo (Kingsnorth Industrial Estate) and RWR (Stratford in East London).
Because the truck I'm on can recycle sewage and re-use it for high pressure drain jetting, excess water just gets put back into the sewer when the job is finished. When cleaning a pump station, it's standard practice to put the water back into the wet well, where the sewage goes and is held before it's pumped, either to the next pump station in the chain or to the nearest sewage works.
