Sent: April :08 PM. Subject: RE: Southwood 4 - Monitoring Well update

Transcription

1 Sent: April :08 PM Subject: RE: Southwood 4 - Monitoring Well update Further to our discussion, I have attached the following reports and letters that we have issued, which generally remain applicable to the Southwood 4 project: Hydrogeological Report for Southwood 3 and 4, Report 3, dated April 11, 2014 Addendum to Report 3, dated July 16, Geotechnical Report for Southwood 3 and 4, Report 4, dated April 25, 2014 Ground Water Monitoring Update, Southwood 3 and 4, Report 5, dated March 18, addressed to Skylar Van Kruistum regarding the Southwood 4, monitoring well update, dated June 24, 2017 Also attached is a copy of our most recent ground water monitoring update, with all data presented from 2015 and For older ground water monitoring data, reference is made to Report 5. Based on the results of the long-term ground water monitoring, (which is now complete for Southwood 3 and Southwood 4), our recommendations in the above reports generally remain applicable and the ground water contour provided in the Addendum to Report 3 remains applicable. It is noted however that the contour plots are for Summer (June 30, 2014) and ground water levels vary by typically more than 1 m throughout the year in the shallow well screens. The Seasonal High ground water level contours provided in Report 5 have been slightly realigned based on the ongoing monitoring program, and are also attached. Southwood 3 (raised fill area) Structural fill was added in the Southwood 3 areas during the 2015 construction season (approximately between May and October), and three new monitoring wells were installed in this area (MW6C adjacent to MW6A, MW7C adjacent to MW7A and MW26, near the high point of the site) to measure the effects of the added fill on the ground water levels. Below, we have tabulated the measured water levels in each of the monitoring wells installed prior to construction (i.e., MW6A and MW7A) and after construction (i.e., 6C, and 7C) for comparison purposes. Southwood 3 Ground Water MW6A (2014) MW6A (2015) MW 6C (2016 / 2017) January / -- February / March / April

2 Southwood 3 Ground Water MW6A (2014) MW6A (2015) MW 6C (2016 / 2017) May June July August September October November December Average Minimum Maximum Southwood 3 Ground Water MW7A (2014) MW7A (2015) MW7C (2016) January <362.2 February March April May June ** July ** August ** September ** October ** November ** December ** Average * Minimum Maximum * Average once the January reading is removed (due to initial reading prior to well stabilizing) ** Well damaged (buried) during construction activities

3 Southwood 3 Ground Water MW26 (2016) January February -- March April May -- June July August -- September October November --** December --** Average Minimum Maximum ** Well damaged during construction activities Where fill was added as part of Southwood 3 construction, the ground water levels have been variable in comparison to prior ground water levels. In general, the water levels in MW7C were similar to the ground water levels in MW7A in years past, however as noted previously, MW7C was damaged due to construction activities shortly after monitoring began. Other than the initial reading in January, 2016, the ground water levels recorded in MW6C were very similar to those recorded in the past in MW6A. Within MW26, which was also installed within the raised Southwood 3 area, the ground water levels have typically been between and m, which is below the fill / native interface, and consistent with the findings before fill was added. It is noted that MW26 was also destroyed, around December, Southwood 4 (homogenized area) Within the Southwood 4 area, the client homogenized an area of the in-situ material (in January, 2016) by excavating the soil to a depth of 1.6 m, mixing it and replacing it. PML installed one monitoring well (MW25B) within the homogenized zone, adjacent to the previously installed MW25A. It is noted that sand seams were observed within the homogenized zone in the new borehole.

4 Southwood 4 Ground Water MW25A (2015) MW25A (2016) MW25B (2016 / 2017) January < / -- February < / March < / April May June July August September October November December Average Minimum Maximum The area where the surficial soils were homogenized (MW25B) has shown higher ground water levels compared to the closest monitoring well outside of the homogenized area (MW25A). It is noted that MW25B is at a higher elevation than MW25A (about 0.5 m) which may in part account for the higher ground water level. Conclusion Based on the results, adding structural fill has not had an appreciable effect on ground water levels over the period monitored. Within the homogenized area, the ground water level has been higher than previous recordings on average, and removing the sand seams within the area has not lowered or removed the ground water from the area over the period monitored. It is noted that, due to the variability of precipitation year to year, a one-year monitoring period may not capture the long term effects of the changes made to the near surface soils. Further to our previous , in addition to MW7C, MW26 has also been damaged and is no longer available for ground water monitoring. As per our proposal, PML will continue to monitor the remaining monitoring wells installed in 2016 (MW6C, MW19B and MW25B) until year end 2017.

5 Please let us know if you require anything further at this point. Regards, Ken Hanes, P.Eng. Project Engineer, Geotechnical and Geoenvironmental Services Peto MacCallum Ltd. 16 Franklin Street South Kitchener, Ontario N2C 1R4 Tel: (519) Fax: (519) Cell: (519) Celebrating 60 Years of Engineering Excellence! Canada s Top 100 SME since 2015

6 Ground Water Monitoring Update, Southwood 3 and Southwood 4 Residential Subdivision PML Ref.: 12KF071 April, GROUND WATER ELEVATION MONITORING INTERIM GROUND WATER MONITORING UPDATE Monitoring Well No. Ground Surface (m) Depth Mid- (m) and (Depth) 28/02/2017 Ground Water / Depth 28/03/2017 6C ~ 3.0 7C ~ B ~ B ~ ~ ** 2.72** ** 3.08** Note: m = geodetic elevation, and mbgs = metre below ground surface (values in Italic); * Monitoring well damaged by farming / construction activities ** Ground elevation changed due to topsoil stripping activities, Readings measured from top of pipe. *** No access to well due to construction activities. Monitoring well decommissioned Monitoring well destroyed Page 1 of 1

7 Ground Water Monitoring Update, Southwood 3 and Southwood 4 Residential Subdivision PML Ref.: 12KF071 January, /2016 GROUND WATER ELEVATION MONITORING INTERIM GROUND WATER MONITORING UPDATE Monitoring Well No. Ground Surface (m) Depth Mid- (m) and (Depth) 30/01/ /02/ /03/ /04/ /05/ /06/ /07/ /08/ /09/2015 Ground Water / Depth 8/11/ /12/ /01/ /03/ /04/ /06/ /07/ /09/ /10/ /12/ ~ 6.8 1A ~ ~ A ~ ~ A ~ 3.0 6B ~ 3.0 6C ~ ~ A ~ 3.8 7B ~ 3.8 7C ~ ~ 6.9 8A ~ ~ ** 6.07** 6.19** 6.16** 6.20** 6.08** 6.18** 6.20** 6.26** 6.15** ** 1.83** 1.95** 1.88** 1.96** 2.26** 2.44** 2.59** 2.84** 2.73** < < < ** ** ** 2.92** 3.15** 3.31** 3.31** 3.34** 3.02** < ** 2.26 * Page 1 of 3

8 Ground Water Monitoring Update, Southwood 3 and Southwood 4 Residential Subdivision PML Ref.: 12KF071 January, /2016 GROUND WATER ELEVATION MONITORING INTERIM GROUND WATER MONITORING UPDATE Monitoring Well No. Ground Surface (m) Depth Mid- (m) and (Depth) 30/01/ /02/ /03/ /04/ /05/ /06/ /07/ /08/ /09/2015 Ground Water / Depth 8/11/ /12/ /01/ /03/ /04/ /06/ /07/ /09/ /10/ /12/2016 9A ~ ~ A ~ ~ A ~ ~ ~ A ~ ~ A ~ ~ A ~ ~ A ~ B ~ < < < < ** ** 2.25** 2.10** 1.81** ** 2.89** 2.98** 2.00** ** 2.63** 2.57** 1.48** < < < < < < * --* 11.88* --* --* --* 11.00* 11.50* --* 11.46* --* ** 9.66** 7.38** 7.30** 7.25** 6.55** 6.69** * < < < ** < ** 3.07** 3.05** 3.05** -- Page 2 of 3

9 Ground Water Monitoring Update, Southwood 3 and Southwood 4 Residential Subdivision PML Ref.: 12KF071 January, /2016 GROUND WATER ELEVATION MONITORING INTERIM GROUND WATER MONITORING UPDATE Monitoring Well No. Ground Surface (m) Depth Mid- (m) and (Depth) 30/01/ /02/ /03/ /04/ /05/ /06/ /07/ /08/ /09/2015 Ground Water / Depth 8/11/ /12/ /01/ /03/ /04/ /06/ /07/ /09/ /10/ /12/ ~ A ~ ~ A ~ ~ A ~ ~ ~ A ~ B ~ * --* --* < * --* --* *** *** *** *** < *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** < < < ** 2.80** 2.61** 2.60** 3.13** * < < < < ~ ** ** 3.75** 3.70** 3.67** Note: m = geodetic elevation, and mbgs = metre below ground surface (values in Italic); * Monitoring well damaged by farming / construction activities ** Ground elevation changed due to topsoil stripping activities, Readings measured from top of pipe. *** No access to well due to construction activities. Monitoring well decommissioned Monitoring well destroyed Ground elevation change due to topsoil stripping activities, Readings measured from top of pipe, Top of pipe not surveyed Page 3 of 3

10 200 m NIGHTHAWK LANE BH 14A EL WHIPPOORWILL DRIVE N BH 14 EL BH 13A EL BH 13 EL BH 12A EL BH 12 EL BH 25A EL BH 25 EL BH 7A EL BH 7B EL BH 7 EL BH 6 EL BH 6B EL BH 6A EL BH 8 EL BH 4 EL BH 5 EL BURLWOOD DRIVE BH 9 EL BH 9A EL BH 8A EL BH 2A EL BH 2 EL BH 3 EL BUTTERNUT PLACE SOUTH PARKWOOD BLVD BH 10 EL BH 1 EL BH 1A EL BH 24 EL BH 23A EL BH 15 EL BH 15A EL BH 23 EL BH 20A EL BH 20 EL BH 16 EL BH 16A EL BH 11A EL BH 11 EL BH 17 EL BH 21 EL BH 18 EL BH 22 EL BH 22A EL BH 19 EL BH 19A EL HIGHWAY 86 (LISTOWEL ROAD) ARTHUR STREET 0 m 40 m 80 m SCALE 120 m 160 m REFERENCE: MONITORING PLAN REPRODUCED FROM DRAWING SUPPLIED BY CLIENT. NOTE: THE INFERRED STRATIGRAPHY REFERRED TO IN THE REPORT IS BASED ON THE DATA FROM THESE BOREHOLES SUPPLEMENTED BY GEOLOGICAL EVIDENCE. THE ACTUAL STRATIGRAPHY BETWEEN THE BOREHOLES MAY VARY. LEGEND: GROUND WATER CONTOUR WITH ELEVATIONS (DATA BASED ON HIGHEST RECORDED MEASUREMENTS FROM 2015/2016) INFERRED GROUND WATER FLOW DIRECTION BIRDLAND DEVELOPMENTS LTD. c/o WALTERFEDY HYDROGEOLOGICAL SITE ASSESSMENT FOR SOUTHWOOD 3 AND SOUTHWOOD 4 RESIDENTIAL SUBDIVISION 1143 LISTOWEL ROAD ELMIRA, ONTARIO SHALLOW GROUND WATER LEVEL CONTOUR AND FLOW DIRECTION (SEASONAL HIGH LEVEL) DRAWN CHECKED APPROVED D. BRICE C O N S U L T I N G E N G I N E E R S K. HANES A. COOKE DATE SCALE PML REF. DWG. NO. APRIL 2017 AS SHOWN 12KF071 REVISED DRAWING 1