2021 Shoal Lake water quality test results

Our staff test Shoal Lake and the intake at the west end of Indian Bay (where the water enters the aqueduct) as part of our routine water quality testing program.

For more information on Winnipeg's drinking water and our impact on Shoal Lake, visit the web page on Shoal Lake - Our Water Source.

Testing

We take samples at the intake every week during the open water season and every two weeks during the rest of the year. We also take samples from the Shoal Lake watershed from May to October. We test the intake samples for:

• routine water chemistry
• metals
• disinfection by-products
• bacteria and protozoa
• pesticides, herbicides and PCBs

By taking these samples, we track seasonal changes in water quality and determine the effects (if any) of human activity within the Shoal Lake watershed.

Water entering the aqueduct intake passes through screens before being treated by chlorine on a periodic basis for slime and Zebra mussel control. The aqueduct brings water to Deacon Reservoir before entering the Water Treatment Plant. There, we test both the raw and treated water before the water is distributed to Winnipeg homes and businesses.

Test results are from January 1 to December 31, 2021

What is being measured	How it's measured	Shoal Lake average	Shoal Lake range
Miscellaneous
Carbon, Dissolved Organic	parts per million	9.2	7.4 to 11.7
Carbon, Total Organic	parts per million	8.8	6.7 to 10.9
Chlorophyll-a	parts per billion	5.2	1.3 to 14.7
Colour, Apparent	TCU	12.8	9.0 to 22.0
Colour, True	TCU	6.8	2.0 to 9.0
Conductivity	microsiemens per centimetre	157	149 to 173
Odour	units	96	75 to 150
pH	units	8.02	7.31 to 8.64
Plankton (algae) count	cells/mL	4,784	344 to 17,790
Solids, Total	parts per million	100	82 to 114
Solids, Total Dissolved	parts per million	79	56 to 99
Temperature	degrees Celcius	10.8	1.9 to 22.9
Turbidity (clearness)	NTU	0.90	0.25 to 2.80
Anions and Nutrients
Alkalinity, Total	parts per million as calcium carbonate	76.6	72.2 to 89.4
Hardness, Total	parts per million as calcium carbonate	77.4	73.4 to 84.7
Chloride	parts per million	2.2	1.8 to 2.5
Fluoride	parts per million	0.08	0.08 to 0.09
Nitrate Nitrogen	parts per million	0.080	<0.003 to 0.363
Perchlorate	parts per billion	<0.20	<0.20 to <0.20
Phosphorus, Total Reactive	parts per million	0.0035	0.0013 to 0.0165
Phosphorus, Total	parts per million	0.0150	0.0096 to 0.0259
Sulphate	parts per million	<0.4	<0.4 to 0.6
Total Kjeldahl Nitrogen (TKN)	parts per million	0.55	0.44 to 0.70
Bacteria
Escherichia Coli	MPN per 100 mL	2	0 to 25
Total Coliforms	MPN per 100 mL	95	0 to >200
Disinfection By-Products
Aldehydes	parts per billion	8.7	3.1 to 11.7
Haloacetic acids	parts per billion	<1.2	<1.2 to 1.4
Trihalomethanes	parts per billion	<2.7	<2.7 to <2.7
Enteric Protozoa
Cryptosporidium	oocysts per 100 L	0	0 to 0
Giardia	cysts per 100 L	0	0 to 0
Pesticides
Alachlor	parts per billion	<0.10	<0.10 to <0.10
Aldrin	parts per billion	<0.010	<0.010 to <0.010
alpha-BHC	parts per billion	<0.010	<0.010 to <0.010
alpha-Chlordane	parts per billion	<0.010	<0.010 to <0.010
alpha-Endosulfan	parts per billion	<0.010	<0.010 to <0.010
Atrazine	parts per billion	<0.10	<0.10 to <0.10
Azinphos-methyl	parts per billion	<0.010	<0.010 to <0.010
beta-BHC	parts per billion	<0.010	<0.010 to <0.010
beta-Endosulfan	parts per billion	<0.010	<0.010 to <0.010
Carbaryl	parts per billion	<0.20	<0.20 to <0.20
Carbofuran	parts per billion	<0.20	<0.20 to <0.20
Chlorothalonil	parts per billion	<0.050	<0.050 to <0.10
Chlorpyrifos	parts per billion	<0.0050	<0.0050 to <0.0050
delta-BHC	parts per billion	<0.010	<0.010 to <0.010
Diazinon	parts per billion	<0.0050	<0.0050 to <0.0050
Diclofop-methyl	parts per billion	<0.10	<0.10 to <0.10
Dieldrin	parts per billion	<0.010	<0.010 to <0.010
Dimethoate	parts per billion	<0.10	<0.10 to <0.10
Endrin	parts per billion	<0.010	<0.010 to <0.010
Eptam	parts per billion	<0.20	<0.20 to <0.20
gamma-Chlordane	parts per billion	<0.010	<0.010 to <0.010
Heptachlor	parts per billion	<0.010	<0.010 to <0.010
Heptachlor Epoxide	parts per billion	<0.010	<0.010 to <0.010
Lindane (gamma-BHC)	parts per billion	<0.010	<0.010 to <0.010
Malathion	parts per billion	<0.10	<0.10 to <0.10
Methoxychlor	parts per billion	<0.010	<0.010 to <0.020
Methyl Parathion	parts per billion	<0.10	<0.10 to <0.10
Metribuzin	parts per billion	<0.20	<0.20 to <0.20
Mirex	parts per billion	<0.010	<0.010 to <0.010
o,p-DDD	parts per billion	<0.010	<0.010 to <0.010
o,p-DDE	parts per billion	<0.010	<0.010 to <0.010
o,p-DDT	parts per billion	<0.010	<0.010 to <0.010
p,p-DDD	parts per billion	<0.010	<0.010 to <0.010
p,p-DDE	parts per billion	<0.010	<0.010 to <0.010
p,p-DDT	parts per billion	<0.010	<0.010 to <0.020
Parathion	parts per billion	<0.0130	<0.0130 to <0.0130
Propaclor	parts per billion	<0.20	<0.20 to <0.20
Propanil	parts per billion	<0.20	<0.20 to <0.20
Propoxur	parts per billion	<0.20	<0.20 to <0.20
Simazine	parts per billion	<0.10	<0.10 to <0.10
Terbufos	parts per billion	<0.10	<0.10 to <0.10
Triallate	parts per billion	<0.10	<0.10 to <0.10
Trichlopyr	parts per billion	<0.50	<0.050 to <0.50
Trifluralin	parts per billion	<0.030	<0.030 to <0.030
Polychlorinated Biphenyls
Arochlor 1016	parts per billion	<0.020	<0.020 to <0.020
Arochlor 1221	parts per billion	<0.020	<0.020 to <0.020
Arochlor 1232	parts per billion	<0.020	<0.020 to <0.020
Arochlor 1242	parts per billion	<0.020	<0.020 to <0.020
Arochlor 1248	parts per billion	<0.020	<0.020 to <0.020
Arochlor 1254	parts per billion	<0.020	<0.020 to <0.020
Arochlor 1260	parts per billion	<0.020	<0.020 to <0.020
Phenoxy Acid Herbicides
2,4,5-T	parts per billion	<0.50	<0.50 to <0.50
2,4,5-TP	parts per billion	<0.50	<0.50 to <0.50
2,4-D	parts per billion	<0.50	<0.50 to <0.50
2,4-DB	parts per billion	<0.050	<0.050 to <0.050
2,4-DP	parts per billion	<0.50	<0.50 to <0.50
Bromoxynil	parts per billion	<0.50	<0.50 to <0.50
Dicamba	parts per billion	<0.0060	<0.0060 to <0.0200
Dinoseb	parts per billion	<0.50	<0.50 to <0.50
MCPA	parts per billion	<0.50	<0.50 to <0.50
MCPB	parts per billion	<0.050	<0.050 to <0.050
Mecoprop	parts per billion	<0.50	<0.50 to <0.50
Picloram	parts per billion	<0.50	<0.50 to <0.50
Total Metals
Aluminum	parts per million	0.00702	0.00098 to 0.02995
Antimony	parts per million	0.000040	<0.000025 to 0.000191
Arsenic	parts per million	0.000812	0.00506 to 0.001185
Boron	parts per million	0.00391	<0.00208 to 0.00712
Cadmium	parts per million	<0.000007	<0.000007 to <0.000007
Calcium	parts per million	19.938	18.707 to 23.946
Chromium	parts per million	<0.00004	<0.00004 to 0.00009
Chromium VI	parts per million	<0.00050	<0.00050 to <0.00050
Copper	parts per million	0.001420	0.000220 to 0.002452
Iron	parts per million	0.03817	0.01190 to 0.12288
Lead	parts per million	<0.000065	<0.000065 to 0.000158
Magnesium	parts per million	5.970	5.252 to 6.899
Manganese	parts per million	0.01095	0.00335 to 0.02718
Mercury	parts per billion	<0.0050	<0.0050 to <0.0050
Nickel	parts per million	0.000162	0.000051 to 0.000334
Potassium	parts per million	1.210	1.070 to 1.449
Sodium	parts per million	2.276	2.060 to 2.650
Uranium	parts per million	<0.000032	<0.000032 to 0.000039
Zinc	parts per million	0.0084	<0.00011 to 0.00219

Note: Where value is expressed as less than (<), the value is halved and used in the calculations, where value is expressed as (>), the value is used in the calculations.

Guidelines for Canadian Drinking Water Quality do not apply to Shoal Lake