HONGKONG'S famed harbour is far from fragrant. All manner of flotsam and jetsam litters the surface, while innumerable liquid pollutants poison the water. Research suggested that the floating refuse originated on land and had been carried through to the harbour along the 90 stormwater outfalls that drain into it. To test the theory, five key outfalls were screened off with meshing designed and installed under Private Sector Committee on the Environment (PSCE) sponsorship. However, the screens caught almost no rubbish at all. The conclusion was that the refuse was finding its way into the harbour from an alternative source - most probably from illegal dumping of construction and other waste by contractors, usually under cover of darkness. If this type of littering proved unstoppable, could the collection of rubbish in the harbour be improved? The existing system was that, under a government-operated scheme, the collectors were paid on a flat rate. The PSCE hired two additional private boats to operate alongside the government-paid crews, but promised payment-by-results. This simplest of incentive schemes yielded tremendous dividends and impressive results. During the nine-month trial period, the private operators' sampans collected five times more floating refuse than the government crews, at only one-and-a-half times the cost. The experiment helped persuade the Government that the entire marine and boat refuse collection system in the harbour ought to be transferred into the private sector.