AECOM Report B&W - N - City of Guelph

City of Guelph2008 Annual ReportClosed Eastview Road Landfill Sitehigher in the well with concentrations ranging from 28 to 53 mg/L, between 2005 and 2008. Theseconcentrations are similar to those recently observed at the downgradient location 37, although the chlorideis significantly lower. This well is also located upgradient of the landfill and, therefore, it is concluded thatthese concentrations are not related to leachate impacts.4.7 Effects of Municipal Water Supply PumpingA condition added to the C. of A. in 1999, Condition 17.10, requires the City to comment on the operation ofthe landfill with respect to the municipal water supply pumping in the Northeast Quadrant. Below is anassessment of the operation of the landfill and the effects of the water supply pumping, following the formatdeveloped through consultation with the MOE.• Review the water level measurements taken in the bedrock beneath the landfill site, and compare theseto the historical database, to confirm that the influence of the City’s water supply pumping system isstable beneath the landfill.• Review of measured bedrock groundwater elevations taken beneath the landfill generally does notindicate any change in levels, excluding seasonal variation, when compared to historical data (Section4.2). In fact water levels in the bedrock have generally increased since 1999 and are now generallysimilar to pre 1997 levels at most locations. As well, similar to 2006, the seasonal variability was muchless than in previous years due to the much higher precipitation in 2008.• Review the municipal water supply pumping records for the northeastern quadrant of the City to confirmthat the water takings are within the historical ranges over the period of record for the monitoringprogram at Eastview Road Landfill.The pumping records were reviewed by City of Guelph’s Water Works personnel and found to be withinhistorical ranges (Appendix H).• Review the results of groundwater sampling and testing from the bedrock beneath the landfill site toconfirm that the Reasonable Use Guidelines for groundwater quality are being met at the site boundariesand, therefore, there is no unacceptable impact from Eastview Road Landfill leachate on the City’smunicipal water supply wells.Reasonable Use continues to be met at the site boundaries (Section 4.4 and 4.5), there is nounacceptable impact on the City’s municipal water supply wells from Eastview Road Landfill leachate.• Review the landfill monitoring results against the predictive analysis of leachate migration from thelandfill site towards the bedrock to confirm that the water quality in the bedrock at the landfill siteboundaries will continue to meet the Reasonable Use Guidelines, and, therefore, there will be nounacceptable impact from Eastview Road Landfill leachate on the City’s municipal water supply wells inthe future.The landfill monitoring results for both chemistry and water level measurements confirm that the bedrockwater quality at the site boundary will continue to meet the Reasonable Use Guidelines (Sections 3.6 and4.5). Therefore, there will be no unacceptable impact from Eastview Road Landfill leachate on the City’smunicipal water supply wells in the future.(111414_2ra_apr29-09_city_of_guelph.doc) - 36 -