title: Use of an Artificial Sweetener to Identify Sources of Groundwater Nitrate Contamination.
abstract: The artificial sweetener acesulfame (ACE) is a potentially useful tracer of waste water contamination in groundwater. In this study, ACE concentrations were measured in waste water and impacted groundwater at 12 septic system sites in Ontario, Canada. All samples of septic tank effluent (n = 37) had ACE >6 µg/L, all samples of groundwater from the proximal plume zones (n = 93) had ACE >1 µg/L and, almost all samples from the distal plume zones had ACE >2 µg/L. Mean mass ratios of total inorganic nitrogen/ACE at the 12 sites ranged from 680 to 3500 for the tank and proximal plume samples. At five sites, decreasing ratio values in the distal zones indicated nitrogen attenuation. These ratios were applied to three aquifers in Canada that are nitrate-stressed and an urban stream where septic systems are present nearby to estimate the amount of waste water nitrate contamination. At the three aquifer locations that are agricultural, low ACE values (<0.02-0.15 µg/L) indicated that waste water contributed <15% of the nitrate in most samples. In groundwater discharging to the urban stream, much higher ACE values (0.2-11 µg/L) indicated that waste water was the likely source of >50% of the nitrate in most samples. This study confirms that ACE is a powerful tracer and demonstrates its use as a diagnostic tool for establishing whether waste water is a significant contributor to groundwater contamination or not.
authors.forename: W D
authors.initials: WD
authors.lastname: Robertson
authors.affiliation: Environment Canada, Burlington, Ontario, Canada.
authors.forename: D R
authors.initials: DR
authors.lastname: Van Stempvoort
authors.affiliation: Environment Canada, Burlington, Ontario, Canada.
authors.forename: J W
authors.initials: JW
authors.lastname: Roy
authors.affiliation: Environment Canada, Burlington, Ontario, Canada.
authors.forename: S J
authors.initials: SJ
authors.lastname: Brown
authors.affiliation: Environment Canada, Burlington, Ontario, Canada.|Department Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Spoelstra
authors.affiliation: Department Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: S L
authors.initials: SL
authors.lastname: Schiff
authors.affiliation: Department Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: D R
authors.initials: DR
authors.lastname: Rudolph
authors.affiliation: Environment Canada, Burlington, Ontario, Canada.|Agriculture and Agri-Food Canada, Fredericton, New Brunswick, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Danielescu
authors.affiliation: Environment Canada, Pacific & Yukon Region, Vancouver, British Colombia, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Graham
mesh_terms: D004784:Environmental Monitoring; D060587:Groundwater; D009566:Nitrates; D009864:Ontario; D013549:Sweetening Agents; D062065:Wastewater; D014874:Water Pollutants, Chemical
chemical_list: D009566:Nitrates; D013549:Sweetening Agents; D062065:Wastewater; D014874:Water Pollutants, Chemical