2017 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, 2017
| What is being measured | How it's measured | Guideline or regulation | Shoal Lake average | Shoal Lake range | Comments |
| Miscellaneous | |||||
| Carbon, Dissolved Organic | parts per million | no guideline | nr | nr | - |
| Carbon, Total Organic | parts per million | no guideline | nr | nr | - |
| Chlorophyll-a | parts per billion | no guideline | 6 | 3 to 11 | Chlorophyll is found in algae |
| Colour, True | TCU | no more than 15 * | 12 | 6 to 18 | Raw water - guideline does not apply |
| Conductivity | microsiemens per centimetre | no guideline | 154 | 140 to 170 | Another measure of dissolved solids |
| Odour | units | inoffensive * | 86 | 75 to 150 | Raw water - guideline does not apply |
| pH | units | between 7.0 and 10.5 | 8.13 | 7.42 to 8.64 | Raw water - guideline does not apply |
| Plankton (algae) count | cells/mL | no guideline | 19,681 | <100 to 79,300 | Algae contribute to odours and may cause filter clogging |
| Solids, Total | parts per million | no guideline | 99 | 82 to 124 | - |
| Solids, Total Dissolved | parts per million | no more than 500 * | 89 | 67 to 108 | Raw water - guideline does not apply |
| Temperature | degrees Celcius | no more than 15 * | 11.3 | 1.7 to 23.8 | Raw water - guideline does not apply |
| Turbidity (clearness) | NTU | no more than 0.3 in 95% of measurements/month, never to exceed 1.0 | 1.16 | 0.28 to 2.63 | Raw water - guideline does not apply |
| Anions and Nutrients | |||||
| Alkalinity, Total | parts per million as calcium carbonate | no guideline | 73 | 65 to 79 | - |
| Hardness, Total | parts per million as calcium carbonate | no guideline | 75 | 68 to 85 | - |
| Chloride | parts per million | no more than 250 * | 1.6 | 0.7 to 1.9 | Raw water - guideline does not apply |
| Fluoride | parts per million | no more than 1.5 | 0.10 | 0.09 to 0.12 | Raw water - guideline does not apply |
| Nitrate Nitrogen | parts per million | no more than 10 | 0.014 | <0.003 to 0.058 | Raw water - guideline does not apply |
| Perchlorate | parts per billion | no guideline | <0.2 | <0.2 to <0.2 | - |
| Phosphorus, Dissolved Reactive | parts per billion | no guideline | 2 | <1 to 7 | - |
| Phosphorus, Total | parts per billion | no guideline | 18.5 | <1 to 39.0 | Phosphorus can contribute to algae growth |
| Sulphate | parts per million | no more than 500 * | <2 | <2 to <2 | Raw water - guideline does not apply |
| Total Kjeldahl Nitrogen (TKN) | parts per million | no guideline | 0.5 | <0.2 to 0.7 | TKN is a combination of ammonia and organic nitrogen |
| Bacteria | |||||
| Escherichia Coli | MPN per 100 mL | none detectable per 100 mL | 13 | <1 to 165 | Raw water - guideline does not apply |
| Total Coliforms | MPN per 100 mL | none detectable per 100 mL | 83 | <1 to >200 | Raw water - guideline does not apply |
| Heterotrophic Plate Count | CFU per mL | no guideline | 145 | 2 to >300 | - |
| Enteric Protozoa | |||||
| Cryptosporidium | oocysts per 100 L | no guideline | <1 | <1 to <1 | 13 samples taken in 2017 |
| Giardia | cysts per 100 L | no guideline | <1 | <1 to 1 | 13 samples taken in 2017 |
| Disinfection By-Products | |||||
| Aldehydes | parts per billion | no guideline | 4.1 | <0.5 to 10.8 | - |
| Bromodichloromethane | parts per billion | no guideline | <0.4 | <0.4 to <0.4 | - |
| Haloacetic acids | parts per billion | no more than 80 | <3 | <3 to 6 | Raw water - guideline does not apply |
| Trihalomethanes | parts per billion | no more than 100 | <3 | <3 to <3 | Raw water - guideline does not apply |
| Total Metals | |||||
| Aluminum | parts per million | no guideline | 0.006 | 0.002 to 0.021 | - |
| Antimony | parts per million | no more than 0.006 | <0.0005 | <0.0005 to 0.0010 | Raw water - guideline does not apply |
| Arsenic | parts per million | no more than 0.010 | 0.0007 | <0.0007 to 0.0010 | Raw water - guideline does not apply |
| Boron | parts per million | no more than 5 | 0.005 | 0.004 to <0.009 | Raw water - guideline does not apply |
| Cadmium | parts per million | no more than 0.005 | <0.0006 | <0.0001 to <0.0006 | Raw water - guideline does not apply |
| Calcium | parts per million | no guideline | 20.2 | 18.1 to 22.3 | Contributes to hardness |
| Chromium | parts per million | no more than 0.05 | <0.0006 | <0.0006 to <0.0010 | Raw water - guideline does not apply |
| Chromium VI | parts per billion | no guideline | 1.9 | <1.0 to <10 | - |
| Copper | parts per million | no more than 1.0 * | 0.0016 | 0.0003 to <0.0050 | Raw water - guideline does not apply |
| Iron | parts per million | no more than 0.3 * | 0.029 | <0.008 to 0.090 | Raw water - guideline does not apply |
| Lead | parts per million | no more than 0.010 | <0.0006 | <0.0004 to <0.0006 | Raw water - guideline does not apply |
| Magnesium | parts per million | no guideline | 5.82 | 5.45 to 6.25 | Contributes to hardness |
| Manganese | parts per million | no more than 0.05 * | 0.0128 | 0.0024 to 0.0306 | Raw water - guideline does not apply |
| Mercury | parts per trillion | no more than 1000 | 0.7 | 0.6 to 1.1 | Raw water - guideline does not apply |
| Nickel | parts per million | no guideline | <0.0005 | <0.0003 to 0.0034 | - |
| Potassium | parts per million | no guideline | 1.18 | 1.08 to 1.36 | - |
| Sodium | parts per million | no more than 200 * | 2.19 | 1.94 to 2.48 | Raw water - guideline does not apply |
| Uranium | parts per million | no more than 0.02 | <0.0006 | <0.0004 to <0.0006 | Raw water - guideline does not apply |
| Zinc | parts per million | no more than 5.0 * | <0.0050 | <0.0009 to <0.0050 | Raw water - guideline does not apply |
| Zirconium | parts per million | no guideline | <0.0005 | <0.0001 to <0.0005 | - |
| Pesticides | |||||
| Alachlor | parts per billion | no guideline | <0.10 | <0.10 to <0.10 | - |
| Aldrin | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| alpha-BHC | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| alpha-Chlordane | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| alpha-Endosulfan | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Atrazine | parts per billion | no more than 5 | <0.10 | <0.10 to <0.10 | Raw water - guideline does not apply |
| Azinphosmethyl | parts per billion | no more than 20 | <0.10 | <0.010 to <0.10 | Raw water - guideline does not apply |
| beta-BHC | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| beta-Endosulfan | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Carbofuran | parts per billion | no more than 90 | <0.20 | <0.20 to <0.20 | Raw water - guideline does not apply |
| Chlorpyrifos | parts per billion | no more than 90 | <0.10 | <0.005 to <0.10 | Raw water - guideline does not apply |
| delta-BHC | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Diazinon | parts per billion | no more than 20 | <0.10 | <0.005 to <0.10 | Raw water - guideline does not apply |
| Diclofop-methyl | parts per billion | no more than 9 | <0.10 | <0.10 to <0.10 | Raw water - guideline does not apply |
| Dieldrin | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Dimethoate | parts per billion | no more than 20 | <0.10 | <0.10 to <0.10 | Raw water - guideline does not apply |
| Endrin | parts per billion | no guideline | <0.010 | <0.010 to <0.040 | - |
| Eptam | parts per billion | no guideline | <0.20 | <0.20 to <0.20 | - |
| gamma-Chlordane | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Heptachlor | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Heptachlor Epoxide | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Lindane (gamma-BHC) | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Malathion | parts per billion | no more than 190 | <0.10 | <0.10 to <0.10 | Raw water - guideline does not apply |
| Methoxychlor | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Methyl Parathion | parts per billion | no guideline | <0.10 | <0.10 to <0.10 | - |
| Metribuzin | parts per billion | no more than 80 | <0.20 | <0.20 to <0.20 | Raw water - guideline does not apply |
| Mirex | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| o,p-DDD | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| o,p-DDE | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| o,p-DDT | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| p,p-DDD | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| p,p-DDE | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| p,p-DDT | parts per billion | no guideline | <0.010 | <0.010 to <0.010 | - |
| Parathion | parts per billion | no guideline | <0.10 | <0.013 to <0.10 | - |
| Propaclor | parts per billion | no guideline | <0.20 | <0.20 to <0.20 | - |
| Propanil | parts per billion | no guideline | <0.20 | <0.20 to <0.20 | - |
| Propoxur | parts per billion | no guideline | <0.20 | <0.20 to <0.20 | - |
| Simazine | parts per billion | no more than 10 | <0.10 | <0.10 to <0.10 | Raw water - guideline does not apply |
| Terbufos | parts per billion | no more than 1 | <0.10 | <0.10 to <0.10 | Raw water - guideline does not apply |
| Triallate | parts per billion | no guideline | <0.10 | <0.10 to <0.10 | - |
| Trichlopyr | parts per billion | no guideline | <0.050 | <0.050 to <0.050 | - |
| Trifluralin | parts per billion | no more than 45 | <0.030 | <0.030 to <0.030 | Raw water - guideline does not apply |
| Polychlorinated Biphenyls | |||||
| Arochlor 1016 | parts per billion | no guideline | <0.020 | <0.020 to <0.020 | - |
| Arochlor 1221 | parts per billion | no guideline | <0.020 | <0.020 to <0.020 | - |
| Arochlor 1232 | parts per billion | no guideline | <0.020 | <0.020 to <0.020 | - |
| Arochlor 1242 | parts per billion | no guideline | <0.020 | <0.020 to <0.020 | - |
| Arochlor 1248 | parts per billion | no guideline | <0.020 | <0.020 to <0.020 | - |
| Arochlor 1254 | parts per billion | no guideline | <0.020 | <0.020 to <0.020 | - |
| Arochlor 1260 | parts per billion | no guideline | <0.020 | <0.020 to <0.020 | - |
| Phenoxy Acid Herbicides | |||||
| 2,4,5-T | parts per billion | no guideline | <0.050 | <0.050 to <0.050 | - |
| 2,4,5-TP | parts per billion | no guideline | <0.050 | <0.050 to <0.050 | - |
| 2,4-D | parts per billion | no more than 100 | <0.050 | <0.050 to <0.050 | Raw water - guideline does not apply |
| 2,4-DB | parts per billion | no guideline | <0.050 | <0.050 to <0.050 | - |
| 2,4-DP | parts per billion | no guideline | <0.050 | <0.050 to <0.050 | - |
| Bromoxynil | parts per billion | no more than 5 | <0.020 | <0.020 to <0.020 | Raw water - guideline does not apply |
| Dicamba | parts per billion | no more than 120 | <0.0060 | <0.0060 to <0.0060 | Raw water - guideline does not apply |
| Dinoseb | parts per billion | no guideline | <0.050 | <0.050 to <0.050 | - |
| MCPA | parts per billion | no more than 100 | <0.025 | <0.025 to <0.025 | Raw water - guideline does not apply |
| MCPB | parts per billion | no guideline | <0.050 | <0.050 to <0.050 | - |
| Mecoprop | parts per billion | no guideline | <0.050 | <0.050 to <0.050 | - |
| Picloram | parts per billion | no more than 190 | <0.20 | <0.20 to <0.80 | Raw water - guideline does not apply |
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.
* Aesthetic objective: These guidelines have an objective and not a maximum acceptable limit. These parameters should not impact the safety of the water to drink and there is no anticipated health risk for short-term exposures.
Guidelines from 'Summary of Guidelines for Canadian Drinking Water Quality' by Health Canada, February 2017
Last updated: April 15, 2024