Diesel invert wastes are one of the more difficult types of drilling mud wastes to dispose of due to the presence of hydrocarbons and salts. In 1989 a joint research program funded by the Alberta Research Council (ARC) and the Alberta Land Conservation and Reclamation Council was initiated to develop environmentally acceptable land application rates of diesel invert wastes for soils in Alberta and to model the fate of these wastes. The work was undertaken as four individual but closely linked experiments. This paper emphasizes the work related to the field study. The characterization experiment included the sampling and analysis of the waste materials and indigenous soils from the field site. The degradation experiment was undertaken to determine degradation rates of the oil, organic carbon and three targeted PAH’s (fluorine, phenanthrene, and pyrene) when applied to soil under laboratory conditions. The objective of the greenhouse pot experiment was to measure the relative impact of the oily materials and salts present in the invert wastes on soil quality and plant growth and quality. The field plot experiment was undertaken to validate and calibrate the results of the degradation and greenhouse experiments. It was established adjacent to the wellsite which was reclaimed using conventional management practices. The oil application rates achieved in the field plots were 0% (control), 1.0%, 2.0%, 3.0%, and 4.0%. Frequency of application included single applications with and without a vegetation cover and multiple waste application plots. Waste was applied and incorporated in October 1990 and again in September 1991 for the multiple application plots. Each treatment (4 m x 5 m plot) was replicated three times and a grass or grass and legume vegetation cover was established. Each of the 54 plots was sampled in 15 cm intervals to the 250 cm depth prior to waste application, 15 days after application, and again in the fall of 1992, 1993, 1994, 1995, and 2003. Tissue samples were collected and biomass was determined. The extent of chloride movement was greatest in year 1 and declined thereafter. By year 5 the highest chloride values were in the 150 to 180 cm depth interval and by 2003 (year 13) the chloride had all been leached beyond the 3 m depth. None of the 2%, 3%, or 4% vegetated or non-cultivated treatments achieved the 0.5% oil content limit by the end of year 5 whereas all of the non-vegetated treatments did achieve the 0.5% target by the end of year 5. For the treatments that did exhibit some level of hydrophobicity, the levels were dominantly slight with only a few in the moderate category. The vegetation cover established at the wellsite where operational reclamation practices were employed was comprised mainly of grasses in 2003. Trees and shrubs were much more common in the adjacent plot area. Overall neither the salt content nor oil content had any long-term effect on vegetation cover establishment and growth. In 2004, the ARC initiated a bench scale experiment to assess the effectiveness of raw and composted mechanical pulp mill sludge for degrading hydrocarbons. The results indicated that both materials have significant potential for use as a soil amendment for remediating hydrocarbon contaminated sites.