Sewage and sewerage

Last week I heard an academic refer to the ‘Werribee Sewerage Treatment Farm’ during a story about the birdlife attracted to the huge lagoons at the facility that treats just over half of Melbourne’s human effluent. In fact, the stuff that arrives at the Werribee plant is sewage: it flows to Werribee through sewers, and indeed through the sewerage system, and after treatment is recycled or discharged into Port Philip Bay. The sewerage, on the other hand, stays where it is.