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