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This study examined bacteria and nutrient quality in tile drainage and shallow ground water resulting from a fall land application of liquid municipal biosolids (LMB), at field application rates of 93,500 L ha(-1), to silt-clay loam agricultural field plots using two different land application approaches. The land application methods were a one-pass AerWay SSD approach (A), and surface spreading plus subsequent incorporation (SS). For both treatments, it took between 3 and 39 min for LMB to reach tile drains after land application. The A treatment significantly (p < 0.1) reduced application-induced LMB contamination of tile drains relative to the SS treatment, as shown by mass loads of total Kjeldahl N (TKN), NH(4)-N, Total P (TP), PO(4)-P, E. coli., and Clostridium perfringens. E. coli contamination resulting from application occurred to at least 2.0-m depth in ground water, but was more notable in ground water immediately beneath tile depth (1.2 m). Treatment ground water concentrations of selected nutrients and bacteria for the study period ( approximately 46 d) at 1.2-m depth were significantly higher in the treatment plots, relative to control plots. The TKN and TP ground water concentrations at 1.2-m depth were significantly (p < 0.1) higher for the SS treatment, relative to the A treatment, but there were no significant (p > 0.1) treatment differences for the bacteria. For the macroporous field conditions observed, pre-tillage by equipment such as the AerWay SSD, will reduce LMB-induced tile and shallow ground water contamination compared to surface spreading over non-tilled soil, followed by incorporation.

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.

The paper outlines the statutory arrangements governing water and sewerage charges in Scotland, and comments on the factors affecting the levels of charges. Trends in revenue expenditure over the period 1989–90 to 1992–93 are considered in relation to increases in personal community water charge levels, metered water rates, and costs per household. Non‐domestic sewerage rates and industrial effluent charges are also discussed. Some comparisons are made with England and Wales and with other countries. The funding arrangements for capital expenditure and their effect on the levels of charges are described, with particular reference to debt levels and rising expenditure to meet UK and EC standards. Factors affecting future charge levels are also identified.