Reuse of rubber crumb from discarded tyres is increasing, including with artificial sports fields, playgrounds, permeable pavement, and drainage media. Artificial sports fields are becoming more common to increase usage and decrease maintenance cost. Modern artificial sports fields use rubber crumb to ‘cushion’ the impact of players. The Auckland Council Parks department began investment of NZ$85 million over 10-years to convert 37 sports fields to artificial turf. Seddon Fields was converted to artificial turf in 2013. In New Zealand, rubber crumb is sourced from discarded tyres. However, tyre wear is a principal source of zinc contamination in the region. An initial mass balance model of rubber crumb was undertaken to assess the order of magnitude of rubber crumb likely discharged from the fields and to adjacent waterways. Previous estimates of zinc sources, run-off and accumulation in the estuarine area of Motions Creek and the Waitemata Harbour are compared to the new source of zinc from Seddon Fields. Initial estimates suggest that rubber crumb runoff from the sports fields constitutes an appreciable source of zinc that merits further assessment regarding local contaminant loads and potential methods to decrease the rubber crumb from reaching the waterways. A potential ‘sustainable reuse’ of discarded tyres may be exacerbating contamination of Auckland’s waterways.
