The source of nitrate contamination in the Abbotsford aquifer is not unequivocally known, but is attributed to long-term agricultural land use practices, such I as poultry manure stockpiling and the spreading of poultry manure and fertilizer directly 1 above the permeable sands and gravels of the aquifer, particularly on the B. C. side of I the International border (Kohut et al., 1989; Zebarth et [...] The objective of this study was to use the 6’5N and 6’80 stable isotopic composition of groundwater nitrate to 1 ) evaluate the origin of nitrates in the Abbotsford aquifer system, and 2) to ascertain whether natural remediation of nitrate in the aquifer by bacterial denitrification. [...] Thus, the 815N and 6180 of groundwater nitrate indicated conclusively that no significant denitrification was taking place in the Abbotsford aquifer, and that the nitrate in the aquifer was predominantly derived from poultry manure nitrogen forms and to a lesser extent from ammonium fertilizers. [...] This required, in the absence of denitrification, the involvement of water in the vitrification process with 6160 values beyond the range of values observed in precipitation (Fritz et al., 1987). [...] In summary, the nitrate oxygen isotope data suggested that most of the NO3 in the aquifer was produced by vitrification of manure N and ammonium fertilizers in the soil zone during the summer months.
- Pages
- 50
- Published in
- Saskatoon
