AECOM Report B&W - N - City of Guelph

City of Guelph2008 Annual ReportClosed Eastview Road Landfill Siteassessment in 1997 recognized this and modelled the overall effects at the site under long-term averageconditions, concluding that the “overall average boron concentrations in the bedrock aquifer will remain wellwithin Reasonable Use Guidelines” (p.9).Based on the assessment of target elevations at individual locations, and the overall assessment for the site,future Reasonable Use exceedances in the bedrock aquifer are not predicted.4.5.2.2 Lower Till Groundwater QualitySampling and testing the water quality in the lower till provides a predictive “early warning” of any leachatemovement towards the bedrock aquifer. Because of the very slow rate of downward flow in the tills beneaththe landfill, as noted above, no leachate should be detected in the lower till in 2008 or for many more years inthe future.A summary of groundwater quality in the lower till during 2008 is provided in Table 8 and is similar toprevious years 11 . Spatially, the water quality is slightly variable but at each location it is stable (i.e., noapparent trends).Table 8. Summary of Lower Till Groundwater Quality During 2008ParametersLower Till Groundwater QualityAvg. Min Max. SamplesGeneralpH 8.33 8.3 8.4 12Conductivity (μS) 321 273 390 12Alkalinity (mg/L) 165 139 205 12Hardness (mg/L) 93 45 180 12Critical Indicators Chloride (mg/L) 2 1 3 12Boron (mg/L) 0.11 0.045 0.25 12Phenol (μg/L)