The effective reuse and recycling of industrial byproducts, namely coal wash (CW) and basic oxygen steel slag (BOS), through large-scale geotechnical projects (e.g. land and port reclamation) is economically beneficial and environmentally sustainable. Nevertheless, due to the heterogeneity of these granular waste materials, the actual performance of compacted fill in the field can be significantly different from that observed in the laboratory. This paper reports the results of a compaction field trial carried out at Port Kembla Outer Harbor reclamation site (Wollongong, Australia) to evaluate the in situ performance of two selected CW-BOS blends. Based on a number of field density tests, it was found that 4 passes of compaction were adequate for achieving a fill density > 90% standard Proctor compaction. A series of dynamic cone penetration tests (DCPTs) confirmed that compacted CW-BOS fills have a greater strength compared to compacted sandy fill, as the number of blows to penetrate 100 mm is greater than 20 for both materials. Furthermore, plate load tests were also performed and swelling was routinely monitored. The results are presented and discussed.