Farm well water quality in Alberta

On-farm groundwater supplies in Alberta were evaluated for chemical (routin e chemistry, trace metals), herbicides and microbiological (total and fecal coliforms) parameters to determine the suitability of domestic drinking wa ter usage based on the Guidelines for Canadian Drinking Water Quality (GCDW Q). The sampling program was conducted between May and October of 1995 and 1996. Thirty-two percent of the 816 farm water wells surveyed (depth range 2 to 284 m) exceeded the GCDWQ for maximum acceptable concentration (MAC) o r interim maximum acceptable concentration (IMAC) of at least one parameter . In addition, the water from 92% of the sites exceeded the GCDWQ for at le ast one of the aesthetic objectives (AO). The chemicals were ranked from mo st to least frequently exceeding the GCDWQ MAC, in the following order: F > > NO3 -N + NOrN > As > Se > Pb > B > U > Cr (13, 6, 3, 3, 2, 0.9, 0.4 and 0.2% of all samples, respectively). The parameters ranked from most to leas t frequently, exceeding the AO, in the following order: TDS > Na > Fe > Mn > pH > SOI > Cl > Al > Zn > Cu (85, 64, 36, 34, 23, 19, 6, 2, 1 and 0.1% of the samples, respectively). The majority of the higher concentrations of m ost inorganic parameters are due to natural geological conditions defined b y source aquifer mineralogy. The effects of primary agriculture are likely limited to the 3% herbicide detections and to some nitrate and microbiologi cal contaminations observed; this water should not be used for human consum ption without some form of site-specific treatment. Some rural residents ma y be "mistreating" their water, and a general lack of water testing among r ural residents was noted.