b'20Monitoring the impact of cattle access points on river water quality using in in-situ high frequency turbidity ONeill M1, Briciu-Burghina C1 and Regan F11DCU Water Institute, School of Chemical Sciences, Dublin City University, Dublin, IrelandCattle with direct access to streams and rivers contribute to deterioration in water qualityarising from contamination with faecal matter, increases in suspended sediment and nutrient enrichment. The exact extent and impact of how cattles behaviour when entering these water bodies affect the quality downstream from cattle access points has not been studied in great detail. In this study, in-situ monitoring of water quality was carried out using 2 multi- parameter sondes (temperature (oC), conductivity (mScm-1), turbidity (NTU), optical dissolved oxygen (ODO) (mgL-1) and pH) installed upstream and downstream from the cattle access point. Motion detection cameras were used to capture cattle entry events and to quantify these events in terms of duration/length (min) and magnitude (number of cows). R studio was used to carry out the statistical analyses of the data and event classification. During the deployment a total of 69 cattle access events were recorded and turbidity data was classified based on event time stamps. Results show there is a positive correlation between the number of cows entering the stream and the resulting impact on turbidity (difference inupstream and downstream turbidity) and between the entry event duration/length (min) and the impact on turbidity. The results identified a site specific threshold corresponding to eight cows and 14 min. When there are more than eight cows present, or the duration of the entry event is higher than 14 min, the impact on turbidity is considerably higher. Keywords: cattle access points; turbidity; nutrients; agri-environmental and sediment.64'