Origination includes cesspool and sewage outfall pipes. Sewage is piped to a community septic tank, with effluent discharge through an ocean outfall. The wastewater treatment system discharges through a marine outfall line to Kuluk Bay. This gives a required discharge outfall capacity. The unusual upstream facing outfall of the Derwent is man made. Once the latter was diverted to King's Lynn in 1236, the Nene outfall deteriorated. There is an ocean outfall from the plant. An ocean outfall line was recently added for seafood processing waste. There is an ocean outfall at Pencarrow Head. The subsets of possible nodes are&colon; junction, outfall, storage and divider. It was mostly constructed on the embankment containing the Northern Outfall Sewer. It is similar to the Ridgeway in south London that covers the Southern Outfall Sewer. The Greenway runs atop Joseph Bazalgette's Northern Outfall Sewer. It treats the waste water from the Northern Outfall Sewer serving North and East London. South of the river, the Southern Outfall Sewer extended to a similar facility at Crossness.