ONTARIO MUNICIPAL BOARD

Transcription

1 PL ONTARIO MUNICIPAL BOARD Eden Oak (Creditview Heights) Inc. has appealed to the Ontario Municipal Board under subsection 34(11) of the Planning Act, R.S.O. 1990, c. P.13, from the neglect or refusal of the Town of Halton Hills to amend Zoning By-law No to permit a development consisting of 33 single detached lots, Part lot 20, Concession 9,Town of Halton Hills Municipal File No. D14ZBA OMB File No. PL Eden Oak (Creditview Heights) Inc. has appealed to the Ontario Municipal Board under subsection 51(34) of the Planning Act, R.S.O. 1990, c. P.13, from the failure of the Town of Halton Hills to make a decision to permit a development consisting of 33 single detached lots, Part Lot 20, Concession 9, Town of Halton Hills Municipal File No. D12SUB OMB File No. PL WITNESS STATEMENT OF TIM LOTIMER February 22, 2017

2 2 WITNESS STATEMENT OF TIM LOTIMER, P.GEO. INTRODUCTION 1. The following witness statement is submitted by Tim Lotimer, Tim Lotimer & Associates Inc., Peer Review Hydrogeologist for the Regional Municipality of Halton (the Region ). 2. My testimony will be directed at Issue 7a on the Town and Region Issues List namely: Will the construction of the sanitary sewer for the proposed development have an adverse impact on private wells within the vicinity of the proposed development? QUALIFICATIONS 3. I am a licensed Professional Geoscientist (P. Geo. Registration #0026) and principal with Tim Lotimer & Associates Inc. 4. Tim Lotimer & Associates Inc. holds a certificate of authorization (#90917) to practice Professional Geoscience in Ontario. 5. I was retained by the Region from 2007 to 2011 as a senior hydrogeologist, primarily for Water Planning/Public Works. In 2011, I was retained by the Region as a Peer Reviewer for Environmental Health/ Health Protection Services and remain in that role. 6. In my current role as Peer Reviewer, I am responsible for review of consultants hydrogeological reports submitted to the Region in support of development applications. In the course of my retainer with the Region, I have peer reviewed over 15 applications. As a result, I am familiar with the development approval process at the Region and the types of conditions and tests that must be met before the Region will approve a proposed planning application. 7. My Curriculum Vitae outlining my professional qualifications and experience is attached hereto as Appendix A. My Acknowledgment of Expert s Duty is attached hereto as Appendix B. MATERIALS REVIEWED 8. Monitoring Program, Eden Oaks Subdivision, Town of Halton Hills (Glen Williams), letter from Hydroterra Limited, January 25, 2010 to the Regional Municipality of Halton, Health Department. This is the original hydrogeological Peer Review report of the proposed development. I generally agree with the conclusions and recommendations of

3 3 this report. However, I note that some aspects of the proposed site servicing have changed since the review of Hydroterra Limited. 9. I will rely on the following documents as part of my evidence: EVIDENCE a. Proposed Subdivision, Glen Williams, Town of Halton Hills, Ontario, letter from V.A. Woods Associates Limited, February 8, 2017 to Edenoak (Creditview Heights) Inc., b. Functional Servicing Report for Proposed Low Density Residential Development by Eden Oak (Creditview Heights) Inc., revised December 2016, prepared by Condeland Engineering Limited. c. Grading Plan, Drawing (June 2016); Plan and Profile Street A, Drawings (January 2017) and (December 2016); prepared by Condeland Engineering Ltd. d. Hydrogeological Investigation, Proposed Subdivision, Part Lot 20, Concession 9, Town of Halton Hills, Ontario; V.A. Woods Associates Limited, Updated June e. Hydrogeological Investigation, Proposed Subdivision, Part Lot 20, Concession 9, Town of Halton Hills, Ontario; V.A. Woods Associates Limited, Updated April f. Hydrogeological Investigation, Proposed Subdivision, Part Lot 20, Concession 9, Town of Halton Hills, Ontario; V.A. Woods Associates Limited, July g. Monitoring Program, Eden Oaks Subdivision, Town of Halton Hills (Glen Williams), letter from Hydroterra Limited, January 25, 2010 to the Regional Municipality of Halton, Health Department. Review of The Functional Servicing Report Wastewater 10. Conveyance for sanitary sewage of the proposed subdivision has been addressed via discharge to the existing Gamble Street sanitary sewer. To ensure that a gravity based conveyance system is attainable, a portion of existing Gamble Street sanitary sewers is to be reconstructed to a point where connection to the existing sanitary sewer invert downstream is achievable. As shown on drawing , the invert of the existing sewer will be deepened from about m asl. to about m asl to accommodate the proposed sanitary sewers for the development. 11. As shown on drawing , the proposed sanitary sewer that services the new development will have an invert of about m asl at the westerly end of the proposed development and m asl at the easterly end, where it connects to the deepened existing sewer.

4 4 Review of the Hydrogeological Reports 12. Boreholes have been drilled at the site. In general these boreholes indicate that low permeability sediments (silts, clays and glacial till) several metres thick overly higher permeability sands. 13. Seven monitoring wells were also constructed to measure the position of the water table within the sand unit. The location of monitoring wells (MW 101 to MW 107) are shown on the figure below, reproduced from the June 2016 (reference d ) report. 14. The results of the water level monitoring are presented in a Table in the June 2016 (reference d ) report reproduced below:

5 5 15. Using the water level information shown in the above Table, the consultant prepared a map showing the contours of the water table, in the June 2016 (reference d ) report, reproduced below. There is a lack of water level data along the proposed location of Street A and the sanitary sewer. We also note that although the reported water levels for MW 101 ranged from to m, the water table contour line was located incorrectly on the drawing. However, the general pattern of the water table contours appear to be reasonable.

6 6 16. The hydrogeological study concluded that (nearby) water wells are unlikely to be affected by trench excavations of less than 3 m of depth. 17. The hydrogeological study concluded that deep excavations that are substantially below the water table will likely require significant dewatering works and should be avoided. 18. However, the hydrogeological study predated the decision to reconstruct and deepen the existing Gamble Street sewer to a depth of 7.3 m (257.5 m asl) to allow connection to the sewer from the proposed development. As a result, an assessment of the potential for impacts to private wells on Chelten Street, that would result from the deepening of the sewer, was not considered in the hydrogeological study. 19. The functional servicing report (reference b ), section C5. Servicing Depth Trench Construction references that sewers will be below or near the measured groundwater level of m. We note that the water table contour map more accurately reflects the interpreted groundwater levels on the property. As such, using this map, it would be possible to estimate the relative depth of the invert of the sanitary sewer in relation to the groundwater level.

7 7 Review of February 8, 2017 Letter (reference a ) 20. In response to the request of the Region, V.A. Woods Associates Limited did a door-todoor survey of private wells close to the proposed development along Chelten Street and Wildwood Road. It was determined that there were five private wells along Chelten Street and four private wells along Wildwood Road that were close to the proposed development as shown on the figure below, reproduced from their report. 21. During the survey, the elevation of the top of all of the wells was measured. Water level in wells were permission to monitor was granted by the homeowner (five wells) was also measured. The available results for the shallow wells, are tabulated in the table below that we prepared. In general, these water level results are considered to be representative of the water table within the vicinity of the private wells. Well depths were obtained from the Ministry of the Environment and Climate Change (MOECC) water well records or from the private well owner.

8 8 Well Address and MOECC well # Elevation (metres above sea level) Depth (metres above sea level) Water Level (metres above sea level) Date of measurement 1 Chelten * (from water well record) Not measured Chelten Chelten Chelten Chelten Wildwood Measured water levels range from an elevation of m asl to m asl. It is not known if these levels were impacted by recent well use. If the water levels had been impacted by recent use, then the non-pumping (static) levels would be higher than those measured, but not higher than ground surface. 23. The water table contour map, in the June 2016 (reference d ) report, appears to be in error within the vicinity of Chelten Street, as measured water levels are much higher than that represented by the water table contours. It appears that the consultant used water levels from Well and Well that are completed in a much deeper aquifer (Geological Cross Section A-A in the June 2016 (reference d ) report ) reproduced below. The water levels for these wells do not appear to represent the water table, but this does not impact our conclusions.

9 9 24. The water levels that were measured in the private wells are all below the proposed sewer invert of about m asl at the westerly end of the proposed development and m asl at the easterly end, where it connects to the deepened existing sewer. Review of Monitoring Program (reference g ) 25. This program listed six tasks to be completed and sets the need for a mitigation strategy in case adverse impacts to private wells occur as a result of construction. To summarize, the tasks related to characterization of existing private wells prior to the start of construction and the requirement for monitoring throughout and after construction for one year. The mitigation strategy speaks to the requirement to provide water to any impacted private well owner. We agree with this program.

10 1 CONCLUSIONS 26. The geotechnical data suggests that dewatering will not be required during construction of the sewer trench, and installation of sewers along proposed Road A. 27. In the event that the method of construction and installation of sewers does require dewatering, as long as the method used to dewater does not lower the water table more than two metres below the proposed sewer invert it should not cause an adverse impact to the private wells along Chelten Street or Wildwood Road. Dated the 22 th of February, 2017 Tim Lotimer, P. Geo.

11 1 APPENDIX A

12 1

13 1 APPENDIX B