LESSONS LEARNED THROUGH THE DEVELOPMENT OF A PERFORMANCE MONITORING PROGRAM FOR GROSS POLLUTANT TRAPS Mohamed Ansaf Kachchu Mohamed*, Terry Lucke** *PhD Student, **Senior Lecturer School of Science, Education and Engineering, University of the Sunshine Coast Maroochydore DC QLD 4558, Australia *mkachchu@usc.edu.au, **tlucke@usc.edu.au ABSTRACT WHILE UNDERTAKING RESEARCH ON AND PERFORMANCE TESTING OF STORMWATER PRODUCTS AT UNIVERSITIES IS GENERALLY MUTUALLY BENEFICIAL FOR BOTH MANUFACTURERS AND UNIVERSITIES AND SHOULD BE ENCOURAGED. IT IS IMPERATIVE TO PLAN EVERY STEP OF THE TESTING PROCEDURE AND TO FULLY UNDERSTAND, AND NOT UNDERESTIMATE, THE CONSEQUENCES OF THINGS GOING WRONG. EVEN AN APPARENTLY VERY SIMPLE TESTING PROGRAM CAN EXPERIENCE A MULTITUDE OF COMPLICATIONS AND REQUIRE EXTENSIVE EXTRA (UNBUDGETED FOR) RESOURCES. THIS PAPER PRESENTS A CASE STUDY ON SOME OF THE PROBLEMS ENCOUNTERED AND THE LESSONS LEARNED WHILE UNDERTAKING PERFORMANCE TESTING OF A PROPRIETARY GPT SYSTEM AT THE UNIVERSITY OF THE SUNSHINE COAST. THE BACKGROUND OF GPTS AND HOW THEY HAVE BEEN TESTED IN THE PAST IS FIRST OUTLINED. THE STUDY METHODOLOGY IS THEN EXPLAINED AND THE SELECTION AND VERIFICATION OF THE MONITORING EQUIPMENT USED IN THE STUDY IS SUMMARIZED. DETAILS ARE GIVEN OF THE UNFORSEEN PROBLEMS THAT OCCURRED BEFORE AND DURING TESTING, AND HOW THEY WERE DEALT WITH. FINALLY, CONCLUSIONS AND RECOMMENDATIONS ARE PRESENTED. KEY WORDS GROSS POLLUTANT TRAP, STORMWATER RUNOFF, POLLUTANT LOADS, WATER QUALITY IMPROVEMENT, WATER SAMPLERS 1. Introduction The growing impact of stormwater pollution has become a major concern to water authorities, governments and public communities alike in recent years. Various pollutants generated in urban catchments are washed off by stormwater runoff into receiving waters and this can reduce the quality of receiving waters and cause harm to the health of aquatic and terrestrial ecosystems [1, 2]. The effects of the pollution contained in urban stormwater runoff include increases in the levels of turbidity, suspended solids, nutrients, heavy metals, micro-organisms, herbicides and pesticides, as well as oils and other hydrocarbons. In addition to these pollutants, urban stormwater can also cause changes in pH, temperature and dissolved oxygen levels in the natural water systems, apart from the damage to their aesthetic values [3]. The increasing concern over the need to safely convey stormwater from urban catchments in a way that minimizes the impact on downstream water bodies has resulted environmental authorities imposing stringent regulations on allowable water quality and pollutant yields of stormwater runoff leaving urban catchments (e.g. NSW DECC, 2007 & ANZECC, 2000) [4, 5]. In response to the growing concerns about deteriorating water quality and new regulations, a number of global initiatives have evolved to address the management of urban stormwater in expanding cities. Water sensitive urban design (WSUD) is one such philosophy that embraces the concept of integrated land and water management [6]. Pezzaniti et al. [6] defined WSUD principles relevant to stormwater as being:  treating stormwater to meet water quality objectives for reuse and/or discharge to surface waters; and  using stormwater in the urban landscape to maximise the visual and recreational amenity of developments. Stormwater quality improvement devices (SQIDs) are now commonly used to minimize the amount of pollutants in stormwater runoff by removing them along the drainage path prior to them reaching receiving waters. The selection of a particular SQID to be used in the field depends on the site conditions and the pollutants to be removed. Numerous studies have demonstrated that significant amounts of pollutants are transported in stormwater as sediment bound contaminants, particularly heavy metals [7, 8]. This suggests that limiting the amount of sediments transported in stormwater runoff will significantly reduce the pollutant load entering receiving waters. Hence, removing the coarse sediments and litter from stormwater runoff is considered to be the primary treatment process in stormwater pollutant minimization [9]. Gross pollutant trap (GPT) is a type of SQID that is specifically engineered to trap and remove visible stormwater pollutants such as litter, debris and coarse