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Application of municipal biosolids (sewage) to agricultural land is a common practice to improve soil physical quality and fertility. Th e chosen method of land application can have a strong impact on the extent of adjacent water contamination by nutrients and bacteria. Dewatered municipal biosolids (DMB) were applied to silt-clay loam experimental fi eld plots in Ontario, Canada using two application methods: (i) surface spreading followed by shallow incorporation (SS) and (ii) a newly developed implement that directly injects DMB into the topsoil (DI). Th e objective of this study was to compare N, P, and bacteria quality of tile drainage and shallow groundwater associated with each land application technique. Th ere were no signifi cant diff erences (P > 0.05) in N, P, and bacteria tile mass loads among the application treatments for time periods <100 d postapplication, when the greatest peak loads and peak tile water concentrations were observed. Both land application treatments caused groundwater Escherichia coli contamination to at least 1.2 m depth below surface after the fi rst postapplication rainfall event, and NO 3 -N contamination to at least 2.0 m depth below surface. Th e DI treatment did, however, have signifi cantly (P < 0.05) higher tile mass loads of total Kjeldahl N (TKN), total phosphorus (TP), E. coli, Enterococci, and Clostridium perfringens relative to the SS treatment for time periods >100 d postapplication. Nevertheless, relative to tile effl uent data collected <100 d postapplication (no application treatment diff erences), peak loads, and concentrations during this time were, overall, considerably lower for both treatments. Th is fi nding, along with no signifi cant diff erences in N, P, and bacteria groundwater concentrations among the application treatments, and that the direct injection technique could potentially reduce vector attraction problems and odor, suggests that the direct injection technique should be considered a dewatered municipal biosolid land application option.

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