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HomeMy WebLinkAboutOES 34-03 CiÚI {]~ REPORT TO FINANCE AND OPERATIONS COMMITTEE Report Number: OES 34-03 Date: September 10, 2003 From: Richard W. Holborn, P. Eng. Division Head, Municipal Property & Engineering Subject: Remediation of an Urban Impacted Watershed and Lagoon, Frenchman's Bay, City of Pickering Final Report - June 2003 Recommendation: 1. That Report OES 34-03 regarding "Remediation of an Urban Impacted Watershed and Lagoon, Frenchman's Bay, City of Pickering, be received for information and 2. That staff consult with various external agencies such as TRCA, MNR, DFO and MOE to discuss the report and next steps, in preparation for a Class Environmental Assessment to address remediation of Frenchman's Bay and 3. That Council endorse, in principal, the acceptance of pursuing a flow balancing system for remediation of Frenchman's Bay, and therefore; a. Direct staff to make the necessary changes to the Stormwater section of Northeast Quadrant Development Guidelines including the deletion of the specific reference to the Bowood property, located on the south side of Kingston Road, west of Fairport Road, as the preferred location for a storm water management facility; and b. Authorize the City Solicitor to advise the Solicitor for Bowood Properties and the Ontario Municipal Board of the City's changed position respecting the Bowood property. Executive Summary: Not Applicable Financial Implications: At this time, there are no financial implications to receiving the Final Report. Staff time and resources will be spent further investigating the merits of a flow balancing system for Frenchman's Bay, and discussions with external review agencies. The estimated cost to undertake a Class Environmental Assessment is $80,000 to $100,000, which staff will propose in the 2004 Budget. A preliminary estimate to construct a flow balancing system in Frenchman's Bay is in the $5 million to $7 million range. Report OES 34-03 Date: September 10, 2003 Subject: Remediation of an Urban Impacted Watershed and Lagoon, Frenchman's Bay, City of Pickering Final Report - June 2003 Page 2 Background: In June 2001, the University of Toronto in partnership with McMaster University undertook a study of the Frenchman's Bay Watershed with specific focus on Frenchman's Bay. The objective was to gather and analyze data to determine the impact that urbanization has on the bay, determine the health of the bay, and suggest a remediation solution. An interim report was completed in June 2002 and the Final Report in June 2003. The Final Report was distributed to the Mayor and members of Council in June. Staff circulated copies to the Toronto and Region Conservation Authority (TRCA), the Ministry of Natural Resources (MNR), the Department of Fisheries and Oceans (DFO) and the Region of Durham's Health Department requesting comments by August 29, 2003. To date, only comments from Durham Region have been received. The consultation process with external agencies will be carried out in the next several months. The City also requested a technical peer review of the report from an engineering consulting firm that specializes in storm water management. (Attachment #1). Aquafor Beech Limited has experience in flow balancing systems and the Class Environmental Assessment process. They have concluded that although a flow balancing system is feasible for Frenchman's Bay, the potential impact of this system on the ecology of Frenchman's Bay was not addressed. Furthermore, other alternative solutions, which may be feasible, were not considered or evaluated. A number of further steps will be required prior to implementing a flow balancing system, namely: 1. Further preliminary discussion with external review agencies 2. Undertake a Class Environmental Assessment 3. Undertake detailed design of the preferred solution 4. Seek out funding alternatives, i.e.; grants, partnerships 5. Construction of the preferred solution 6. Monitoring and maintenance Report OES 34-03 Date: September 10, 2003 Subject: Remediation of an Urban Impacted Watershed and Lagoon, Frenchman's Bay, City of Pickering Final Report - June 2003 Page 3 Should Council concur with the strategy presented above, staff will follow up and carry on the process and necessary budgeting for required works. The acceptance of a flow balancing system for Frenchman's Bay as a remediation solution to be pursued, means that the City will no longer need to consider a storm water management facility for Amberlea Creek on the land referred to as the "Bowood Property". This land is located on the south side of Kingston Road, west of Fairport Road. Since there is no further information to support the feasibility of a pond on the site, it is recommended that consideration of the site be abandoned and the owner and the Ontario Municipal Board be so advised, through the Solicitor for the City. Attachments: 1. Technical Report from Aquafor Beech Limited Prepared By: Everett Director Operations & Emergency Services RH:ds Attachments I: \CO UNCIL \0 ES34-03 .docSep-O 3 Copy: Chief Administrative Officer Director, Planning & Development Solicitor for the City <Iy . .' Thomas J. Quinn, . er i~';-"!'\(~HMENT#--L. TOREPORT# OE"S 3L\-C3 --L.of. ~ 08 September 2003 Pr~ectNo, 64289P Operations & Emergency Services Dept City of Pickering Pickering Civic Complex 1 The Esplanade Pickering, Ontario LIV 6K7 Attention: Me Richard, W. Holborn. P.Eng Re: Proposed Flow Balancing System ~ Frenchman's Bay This letter will summarize: . History of the flow balancing system; . Locations where they exist; . Effectiveness of the systems; and . Technical feasibility of a flow balancing system in Frenchman's Bay History of the Flow Balancing System (FBS) The Dunkers Flow Balancing System (DFBS) was developed by Mr. Karl Dunkers, Stockholm- Taby, Sweden, in the late 1970s. The system is used to store and treat stormwater runoff by allowing pollutants contained in stormwater to settle out naturally (ie: by gravity). In its basic form, the flow balancing system consists of a series of floating cells (Figure 5.1). Each cell is comprised of pontoons and curtains which store the flows. As polluted stormwater enters the DFBS, lake water is displaced through an opening in the curtain. After the runoff ceases to enter the facility, a pump is activated with conveys the flows to the receiving body of water. The polluted water is, therefore, gradually replaced by the lake water and the system is ready for the next runoff event The FBS has the potential to remove a significant (70 percent) of the pollutants that enter the system. As the accompanying photos illustrate the systems are easy to construct and install and typically can be integrated into the existing environment Locations where FBS exist The initial FBS were installed in Sweden in the 1970's. Three facilities were installed. Three additional facilities exist in North America; one in New York City and two in Toronto. The two facilities in Toronto are installed in the former municipalities of Etobicoke and Scarborough. "iENT# I TOREPOrfl H...Q.e.S "3 L --c5 2- of g -"'" The facilities range in size from about 5,000m3 to 40,000m3. The largest facility is currently operating in Scarborough. The facility was designed by Aquafor Beech Limited. Aquafor also undertook the technical feasibility, preliminary design and construction supervision for the installation at the Scarborough site. Effectiveness of the FBS The Scarborough facility has been monitored by Environment Canada and MOE as part of the SW AMP program. A report summarizing the effectiveness of capturing pollutants from stormwater runoff is expected later this year. Initial discussions with one of the provincial representatives involved with the monitoring program suggests that the facility is performing as well, or better than anticipated. The design of the FBS in Scarborough assumed that 70 percent of the pollutants entering the facility would be captured. The removal rate is similar to that of a stormwater quality pond. Technical feasibility of a FBS in Frenchman's Bay A conceptual plan for a Flow Balancing System in Frenchman's Bay has been prepared and is attached to this letter. Based on initial calculations it would seem that it is technically feasible to construct a FBS within Frenchman's Bay. The technical feasibility was determined based on the drainage areas of Dun barton, Amberlea & Pine Creeks, the surface area available within Frenchman's Bay and initial flow rates and pollutant levels as taken from existing background reports. The concept plan as shown would have flows enter the facility at three locations (ie: the outlets of Amberlea, Pine and Dunbarton Creeks). Flows would be directed through a series of cells to a singular outlet. The surface area of the facility is roughly 40,000 m2. In order of achieve a minimum depth of2 m (this depth is required in order to allow pollutants form stormwater to settle out) dredging of existing sediments would have to be undertaken. Should you have any questions please contact the undersigned. Sincerely; AQUAFOR BEECH LIMITED David Maunder, M.Sc., P.Eng Project Manager DEM: jc ATTACHMENT # I TOREPORT# ("::::"'" :>4-(;) '7; of 9} E Q) +-' en ~ U) 0) c: u c: CO CO CD ..c: 0) :J 0 "- 0 ..Q "- CO U U) '+- 0 ç () Q) ..c: +-' '+- 0 en 0 +-' 0 ..c: a.. Q) .> +-' CO +-' c: Q) en Q) "- c.. Q) a:: t:,rTACHMENT1+__,L TO,REPORltt:...Q.¿S. 3t+.-L:l 4- of <6 - Figure 85 Existing facility at Bluffers Park, Scarborough. A; Pre-construction (1992) showing outlet of combined sewer and B; post-constructlon (2003) showing the indMdual ponds that make up the facfllty and Inaeasing clarity of water in outefTr'lost cells. C; View of facUity, June 2003. ATTACHMENT# ! TO REPORT# é C'-J 3~ -DS .5 of <;!. Areal View of the City of Scarborough Flow Balancing System. u ATTACH~1ENT#-L. TO REPORT#~ 34-fJS b of <Z - .c 0) ::J 0 .... 0 1: ~ en .....- 0 ~ ~ U '- Q) E ..... J2 -- E Q) ~ C/'J ~ CI) C') c: 'Õ c: co ~ CO ~ 0 u.. I~~i ~J~ ATTACHMENT#_L. TOREPORT# Ú c- ~ 3LI-C~) /for ç¿ ~ ~ IIJ ~ .~ 'ii ø:I ~ r.: u ~ ð 15 'a I ~ I - Y") ~ ~ ~ ~..~... W' ~. ""- !:.\-", '---, . " ,:' ~ ... Figure 64 A: Conceptual design for a pond/wetland system in the north end of Frenchman's Bay. Courtesy of Aquafor Beech Ltd. and Schollen & Company Inc. Design incorporates Waterfront Trail, additional walkways, overlook to bay with environmental exhibits and protective canopy. Arrows indicate direction of water flow within the pond/wetland system. B: Existing conditions and approximate areal extent of flow balancing system. y' 3: m Z ~;:.,..'.j: I . % ,- g,,! rod ~ ." 0 ~ : :.¿: ~ li W -c:. \ \<:::' v""