Mysterious "plumes" of oddly-coloured water drifting close to some of Cape Town's best-known beaches have prompted a row over the city's sanitation policy. The plumes, in Hout Bay and near Green Point, not far from Clifton and Camps Bay, were photographed last month by Cape Town photographer Jean Tresfon.He posted them to Facebook, prompting dozens of outraged comments. Clifton and Camps Bay beaches have blue flag status and are among Cape Town's main tourist beaches.Tresfon claims the plumes consist largely of untreated sewage.He says they occur close to city waste-water "outfalls" which discharge largely untreated sewage into the sea via underwater pipelines. Tresfon said his camera never lies."Both plumes are exactly where the [sewage pipe] outfalls are marked on the charts," he said.Tresfon's latest photo - of an apparent sewage plume in Hout Bay - elicited shocked comments on Facebook. Sophia van Coller said: "Eeeeeuwwww. That is shocking. I'm definitely not diving there."An earlier photo showed an offshore plume near Green Point. Last year the Sunday Times reported on a slightly elevated level of E.coli - a bacteria associated with human waste - at Clifton.Cape Town acting mayoral committee member for utility services Brett Herron said the city was aware of Tresfon's photographs but the outfall pipes in question had been inspected and found to be in working order.The City of Cape Town is set to approve the controversial sale and lease of a multi-million-rand property in Clifton, despite opposition from a number of residents.The Clifton Precinct, comprising four erven, is estimated to be worth about R100-million.It has garages used by bungalow owners in Clifton, a restaurant and sports grounds.In a report to Mayor Patricia de Lille and her full committee on Friday, the city said it wanted the winning bidder to build underground parking garages. It also wants a "commercial space" for a retail business and "a limited number of boutique line shops".The winning bidder will operate and manage the development on a long-term lease.Additional reporting by Aphiwe De Klerk..