Horn, A & Thomas, EG 2014, 'Paste fill delivery/distribution failures – causes, costs and mitigation/prevention', in Y Potvin & T Grice (eds), Mine Fill 2014: Proceedings of the Eleventh International Symposium on Mining with Backfill, Australian Centre for Geomechanics, Perth, pp. 243-247, https://doi.org/10.36487/ACG_rep/1404_18_Thomas (https://papers.acg.uwa.edu.au/p/1404_18_Thomas/) Abstract: Paste fill formulations focus on use of treated mine/mill waste materials and a variety of additives to reduce the impact/costs of surface waste disposal and improve pertinent underground mining parameters, in the main cost, reserves recovery and local and regional ground stability. Cost of such additives must be optimised. Mix and/or delivery mismanagement can result in costly pipeline and/or borehole blockages. Delays to production are the main cost impacts. Actual costs of pipeline/borehole clearance are of secondary importance. This paper first describes paste fill preparation and delivery mechanisms and then various performance failure modes including disaggregation, in-void dilution and inappropriate slurry rheology. Topics considered include fill delivery reliability, adherence to specifications, mix formulation cost effectiveness and commercially available additives.