Development Services Committee
	TO:	Mayor and Members of Council
	FROM:	Alan Brown, Director of Engineering
	PREPARED BY:	Alan Brown
	DATE OF MEETING:	November 18, 2003
	SUBJECT:	19^th Avenue Hydrogeological Study

RECOMMENDATION:

That the Engineering Department and Terraprobe report back with findings and recommendations, including consultation with the Region of York as applicable;

And that the Region of York be requested to collect additional ground water level data within the shallow monitoring wells in the vicinity of 19^th Avenue prior to proceeding with dewatering for Phase II;

And the Paul Jankowski, Director of Transportation and Works Department at the Region of York be advised accordingly.

PURPOSE:

The purpose of this study is to review the hydrogeology and local ground water use along 19^th Avenue between Warden and Kennedy and to determine the cause of water well complaints in this area.

BACKGROUND:

With the dewatering program for the Region of York’s Phase I - 16^th Avenue Sewer, there has been a number of complaints about water quantity/quality in the 19^th Avenue area from approximately Warden Avenue to Kennedy Road. The Region and its hydrogeologist to date have advised residents that they are not impacting the wells in this area. With the cause of the

well problems being unknown, the Engineering Department retained Terraprobe to investigate a well problem at 4165 - 19^th Avenue (Walker Residence). The following conclusions were presented in Terraprobe’s September 30, 2003 report:

• The shallow well at 4165 19th Avenue has not been affected by the dewatering activities associated with the Region’s 9th Line and the 16th Avenue sewer projects.

• The majority of the wells in this area derive their water from a shallow aquifer system.

• There is a limited supply of water in the aquifer which may be over utilized

• There are two large water users within about 1 km of the area: (Meadowbrook G. & C.C. and Mandarin G. & C.C.) No specific details were available regarding their Ministry of Environment Permits to Take Water, their water use, or aquifer source.

• Additional ground water level data within the shallow monitoring wells in the vicinity of 19th Avenue should be collected prior to the advancement of the Region’s Phase II dewatering activities along 16th Avenue.

DISCUSSION:

Additional research is required to assess the local ground water resources in this area, and the basis for resident complaints. It is recommended that the Town retain Terraprobe at an estimated cost of $5,000 to determine the following;

· Extent of the shallow aquifer

· Which wells are supplied by the shallow aquifer

· Demand on shallow aquifer by residents and heavy water users

· Impact of heavy water users

· Remedial action

Staff will report back to committee on the results of this work and consult with the local Councillors regarding consultation with the area residents. The Region of York will be consulted through the review process and in regard to any applicable follow up recommendations. At a minimum, the Region will be requested to collect additional ground water level date within the shallow monitoring wells in the vicinity of 19 the Avenue prior to proceeding with dewatering for Phase II of the 16^th Avenue Deep Sanitary Sewer Project.

FINANCIAL CONSIDERATIONS:

The total cost to retain Terraprobe to complete this study is estimated to be $5,000 to be funded from the Engineering Departments 2003 Operating Budget.

Alan Brown, C.E.T. Director of Engineering

Jim Baird, M.C.I.P., R.P.P. Commissioner of Development Services

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Q:\Development\Engineering\REPORTS\2003\12\19th Ave HydroG.doc