Councils are becoming more reliant on Gross Pollutant Traps (GPTs) to improve the water quality of their waterways. A group of Macquarie University students undertook an important literature review to see if the five most common GPTs in the Georges River catchment were doing their job.
The students discovered there was a lack of information regarding many aspects of GPT performance. They found that cost, maintenance, safety and inappropriate locations caused inefficiencies and issues with GPT performance. There were also discrepancies between manufacturers claims and in-situ performance. For example, some manufacturers claimed their GPTs removed up to 93% of solids, while it was reported that some GPTs contributed to pollution issues. There were also discrepancies between the reported values from councils and maintenance crews.
In summary, the paper recommended that maintenance guidelines should be implemented for every GPT device and further testing undertaken. A standard system for assessing effectiveness including specifics regarding locations and safety should be implemented. A cost efficiency evaluation should be implemented including a set of minimum performance goals. These recommendations would ensure councils and other buyers were fully informed and that their expensive device met a minimum standard. Please read the very informed review.