When Greensward was purchased by Worthing Council in 1936 there was a very specific clause relating to the laying of a sewer system and mains drains. Click here. There was is even a pumping station to the left of Amberley Drive (refered to as ESS Mast on the land registry documents).
One of the biggest challenges for any property developer is water drainage and poop, which we as humans produce. Under Goring Gap is an existing system designed to cater for hundreds of homes. Our forefathers planned this and worked hard to lay the infrastructure.