CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region Groundwater Quality Vulnerability Analysis - WHPA delineation & vulnerability CTC SWP Committee October 20, 2009 Rick Gerber 1 1 Made possible through the support of the Government of Ontario
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca Overview Overview 1) Technical Rules/Technical Bulletins � > November 20, 2008 2) WHPA & Vulnerability Delineation � Velocity/travel times 3) Peel Region (TRCA) WHPAs � Earthfx Inc (October 17, 2007) � AMEC Peer Review (August 21, 2009) 4) Conclusions/Discussion 2 Made possible through the support of the Government of Ontario
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca 1. Technical Rules/Bulletins (Nov, 2008) 1. Technical Rules/Bulletins (Nov, 2008) Groundwater Quality Vulnerability Analysis – WHPA • Assess the intrinsic vulnerability according to the natural susceptibility of aquifers to becoming contaminated 1) Delineate Wellhead Protection Area (WHPA-A,B,C,D; Part V Part V); 2) Determine natural vulnerability of aquifer system to contaminants (H,M,L – Part IV Part IV); 3) Overlay 1 & 2 to determine vulnerability scores (Part VII.3 Part VII.3). � Consider anthropogenic transport pathways (Part IV Part IV) � Assess uncertainty with plans for continuous improvement (Part I.4 Part I.4) • Threats and Issues mapping within WHPA (Vulnerability score of 6) (Part XI Part XI) • Risk Score = Hazard Rating (1-10) x Vulnerability Score (6) (Part XI Part XI) � Vulnerability score <=6 cannot contain a significant threat � (Significant > 80; Moderate 60-79; Low 40-59) 3 Made possible through the support of the Government of Ontario Slide modified from MOE 24-Mar-2009
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca 4 2 6 4 Made possible through the support of the Government of Ontario Slide from MOE 24-Mar-2009
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca 2. WHPA & Vulnerability Delineation 2. WHPA & Vulnerability Delineation • v = Ki/n = average linear velocity; where K = hydraulic conductivity (constant of proportionality describing ease with which a fluid can move through a porous media) i = hydraulic gradient n = porosity 5 From Freeze & Cherry (1979) Made possible through the support of the Government of Ontario Average linear groundwater flow velocity
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca K=hydraulic conductivity v = Ki/n Note range Higher K = Higher average linear groundwater flow velocity 6 From Freeze & Cherry (1979) Made possible through the support of the Government of Ontario Hydraulic conductivity
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca i=hydraulic gradient; higher i = higher avg linear gw flow velocity v = Ki/n From Freeze & Cherry (1979) 7 Made possible through the support of the Government of Ontario Hydraulic gradient
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca ~30% ~15% >50% n=porosity; higher n = lower avg linear velocity v = Ki/n (<1%) From Freeze & Cherry (1979) From Freeze & Cherry (1979) 8 Made possible through the support of the Government of Ontario porosity
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca Good Aquifer: v=Ki/n=(1e-4 m/s)*0.01/0.3 = 105 m/yr (avg linear flow velocity) note - fracture flow can be much higher (m/d) 9 Made possible through the support of the Government of Ontario Average linear groundwater flow velocity
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca Contaminant Transport • Contaminants can move at the average linear groundater flow velocity (e.g chloride) OR • Movement can be slower (e.g. sorption, dispersion, diffusion according to concentration gradients, etc); • Decrease mass but not necessarily velocity (e.g. dilution, radioactive decay, biodegradation, chemical reactions, ion-exchange, etc); and • Increase velocity (colloidal transport, complexation, etc) 10 Made possible through the support of the Government of Ontario Contaminants interact w physical, chemical & biological system
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca Groundwater Vulnerability (WHPA) a) Delineate Vulnerable Area – WHPA (A,B,C, C1-10yr and D) b) Assign intrinsic vulnerability � 0-5yrs High, 5-25yrs Medium, >25yrs Low Relative Intrinsic Vulnerability c) Overlay WHPA zones with Intrinsic Vulnerability to give Vulnerability Score d) Constructed pathways Unsaturated till UZAT e) Uncertainty JHL ½ WAAT WWAT Saturated till SWAT WAAT SAAT Saturated aquifer 2 year TOT (WHPA: A=100m; B=2yr C=5yr and D = 25 yr) 11 Made possible through the support of the Government of Ontario d) Numerical GW Flow Modelling – WAAT/SAAT
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca CTC SWP - Municipal Pumping Rates ~0.4 m 3 4,500 Lyndsay Court 4,000 3,500 Cedarvale 4A pumping rate (m3/d) 3,000 Palgrave 4 Orangeville 5-5A 2,500 2,000 Stouffville 3,5 1,500 Palgrave 3 Caledon East 4 1,000 500 0 e 1 3 A 3 A 6 l A 2 l 2 3 A A B C B 2 A 1 2 2 3 4 l l 7 8 6 0 1 1 3 4 2 3 2 3 4 2 3 2 3 3 4 1 2 3 5 6 r 3 e e e H H 1 4 9 1 1 2 # # # # # # # # l 5 o 8 8 8 l l # # # # # # # # # # # # # # # # l W l W e l l l l l l l l l l l l l e l l l - m - e e l e e e e m m t t t i l l e e e l l 5 l e e A e e l n n d d e e e n n g g y y e e e e e v l l W e W W l n s s s W W l l l W e e e W W W e e i W x k v s l l 9 l l o o o o o a a a v v v o o r r t t l l l l l t l l l a a i i l l l l l W W r e l l l i i W u u U W W s i i i o o a a a C C i i i i i u r e v v v v t d d E E E t t v v v v v v s s h h e e b b e n n a l a e e l e n n l g e e s A e e w w r r r f f f f f o e e e d n n n P i d g g g l l n n g g f f f f f e l e o v P l e k n n n n b b a n i i h h n g g l g g l l u u u u u C r r g o o a a e e e e A e i a l l l i i n n l l s E E g g a v n n l o o o o a a a o o e e o o o o o a v a i n n n o l l L t - o o C C t t d g e L i g g d d d i i r y c r r r a a l l P P P N N l l K K t t t t t v v s a a a W W C t e e K K a u u n O 7 a n n S S S S S a h i e g e e e r r s v r r r r d r h h a d a p b b a O O O O v I I s t a e O n l l l e n C C a a a 4 s s d e d d s r a l l r c D l a a a O e C C C C o l l l e e n l l i r n n n l s i i v O s C C r H H i i i i L P e b r d d I P g O r r a a n C C a r O 12 Made possible through the support of the Government of Ontario 2005/2006 municipal pumping rates
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca Q = 0, -1000, etc m 3 /d (x=y=5000m) Recharge = 15 mm/yr � 50m K h /K v (m/s) S s (1/m)/S y n � upper aquifer-a 10 -4 /10 -5 1e -4 /0.30 40m 0.3 CH=50m � � upper-aquifer-b 10 -4 /10 -5 1e -4 /0.30 CH=41m 0.3 CH=50m 30m lower aquitard 10 -8 /10 -9 1e -6 /0.10 10m 0.1 � � lower aquifer 10 -4 /10 -5 1e -4 /0.30 CH=25m 0.3 CH=45m 0m y=10,000 m 13 Made possible through the support of the Government of Ontario Numerical GW Flow Modelling – estimate travel times
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca Lower aquifer - steady state particle traces Q=1000 m 3 /d Q=2000 m 3 /d Lower aquifer Q=2000 m 3 /d; 25yr TOT Upper aquifer;Q=1000 m 3 /d;25yr TOT Lower aquifer;Q=1000 m 3 /d;25yr TOT 14 Made possible through the support of the Government of Ontario
CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region CTC Source Protection Region www.ctcswp.ca Upper aquifer; Q1000 m 3 /d; steady state particles No pumping ~450 m/25 yr Lower aquifer; Q1000 m 3 /d; steady state particles Lower aquifer; Q1000 m 3 /d; 25yr TOT ~1250 m/25 yr Lower aquifer; Q2000 m 3 /d; steady state particles Lower aquifer; Q2000 m 3 /d; 25yr TOT ~1550 m/25 yr 15 Made possible through the support of the Government of Ontario
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