I hope someone can guide me. I have three waste water outlets (Bath, basin and kitchen sink) entering a concrete hopper in my 1960's bungalow. This continuously overflows so I plunged my hand down (in a glove) and found a bit of sludge in the bottom but there was not a pipe leading out of the drain to take the water away??? Where should the waste water go? is it a soak-away? What can I do to stop the over flowing?