2011 Shoal Lake water quality test results

Image of Shoal Lake inlet 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
taste and odour compounds
metals
disinfection by-products
bacteria and protozoa
toxins produced by algae

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.

What is being measured	How it's measured	Guideline or regulation	Shoal Lake average	Shoal Lake range	Comments
Odour	�units	Inoffensive	125	70 to 200	Raw water - guideline does not apply
Plankton (algae) count	�cells/mL	no guideline	46,339	1000 to 655000	�Algae contribute to odours and may cause filter clogging�
Chlorophyll-a	parts per billion	no guideline	6	<1 to 15	�Chlorophyll is found in algae�
Cryptosporidium	oocysts per 100 L	no guideline	<1	<1 to <1	14 samples taken in 2011 - no positive results
Giardia	cysts per 100 L	no guideline	<1	<1 to <1	14 samples taken in 2011 - no positive results
Turbidity (clearness)	NTU	no guideline	1.18	0.33 to 3.39	-
Colour, True	TCU	no more than 15	5.2	1 to 13	Raw water - guideline does not apply
Total Solids	parts per million	no guideline	103	88 to 115	-
Total Dissolved Solids	parts per million	no more than 500	89	73 to 102	Raw water - guideline does not apply
Conductivity	microsiemens per centimetre	no guideline	148	127 to 165	Another measure of dissolved solids
pH	�units	between 6.5 and 8.5	8.05	7.44 to 8.73	Raw water - guideline does not apply
Temperature	degrees Celcius	no more than 15	8.1	2 to 22.5	Raw water - guideline does not apply
Total Alkalinity	parts per million as calcium carbonate	no guideline	73	64 to 81	-
Total Hardness	parts per million as calcium carbonate	between 80 and 100	75	68 to 80	Raw water - guideline does not apply
Total Organic Carbon	parts per million	no guideline	11	8 to 14	-
Soluble Organic Carbon	parts per million	no guideline	10	8 to 13	-
Total Kjeldahl Nitrogen (TKN)	parts per million	no guideline	0.58	0.37 to 0.9	TKN is a combination of ammonia and organic nitrogen
Total Phosphorus	parts per million	no guideline	0.016	0.003 to 0.05	Phosphorus can contribute to algae growth
Dissolved Reactive Phosphorus	parts per million	no guideline	0.003	<0.001 to <0.010	-
Fluoride	parts per million	no more than 1.5	<0.08	<0.08 to <0.08	Raw water - guideline does not apply
Nitrate Nitrogen	parts per million	no more than 10	0.016	<0.003 to 0.099	Raw water - guideline does not apply
Chloride	parts per million	no more than 250	<5	<5 to <5	Raw water - guideline does not apply
Sulphate	parts per million	no more than 500	<5	<5 to 6	Raw water - guideline does not apply
Trihalomethanes	parts per billion	no more than 100	<0.5	<0.5 to 0.6	Raw water - guideline does not apply
Bromodichloromethane	parts per billion	no more than 16	<0.5	<0.5 to <0.5	Raw water - guideline does not apply
Haloacetic acids	parts per billion	no more than 80	<5	<5 to <5	Raw water - guideline does not apply
Aldehydes	parts per billion	no guideline	<2	<2 to 4	-
Calcium	parts per million	no guideline	19.7	16.8 to 21.9	Contributes to hardness
Magnesium	parts per million	no guideline	5.8	5.1 to 6.5	Contributes to hardness
Sodium	parts per million	no more than 200	2.0	1.8 to 2.3	Raw water - guideline does not apply
Potassium	parts per million	no guideline	1.3	1.1 to 1.5	Raw water - guideline does not apply
Iron	parts per million	no more than 0.3	0.03	<0.01 to 0.06	Raw water - guideline does not apply
Copper	parts per million	no more than 1.0	0.003	<0.001 to 0.017	Raw water - guideline does not apply
Lead	parts per million	no more than 0.010	<0.001	<0.001 to <0.001	Raw water - guideline does not apply
Aluminum	parts per million	no more than 0.1	0.002	<0.001 to 0.004	Raw water - guideline does not apply
Antimony	parts per million	no more than 0.0006	<0.001	<0.001 to <0.001	Raw water - guideline does not apply
Arsenic	parts per million	no more than 0.010	<0.001	<0.001 to 0.001	Raw water - guideline does not apply
Nickel	parts per million	no guideline	<0.001	<0.001 to 0.001	-
Chromium	parts per million	no more than 0.05	<0.001	<0.001 to <0.001	Raw water - guideline does not apply
Boron	parts per million	no more than 5	0.014	0.009 to 0.019	Raw water - guideline does not apply
Cadmium	parts per million	no more than 0.005	<0.001	<0.001 to <0.001	Raw water - guideline does not apply
Manganese	parts per million	no more than 0.05	0.009	0.003 to 0.021	Raw water - guideline does not apply
Uranium	parts per million	no more than 0.02	<0.001	<0.001 to <0.001	Raw water - guideline does not apply
Zinc	parts per million	no more than 5.0	0.002	<0.001 to 0.009	Raw water - guideline does not apply
Zirconium	parts per million	no guideline	<0.001	<0.001 to <0.001	-
Mercury	parts per million	no more than 0.001	<0.000001	<0.000001 to 0.0000049	Raw water - guideline does not apply

Guidelines from 'Summary of Guidelines for Canadian Drinking Water Quality' by Health Canada, revised February 1, 2012.

This page is printer friendly.

Last updated: April 15, 2024

Top of page

Was this information helpful?

How can we make this web page better?

Information collected will be used to improve our website. Do not use this form to submit a request for service or information because it will not be forwarded to departments for response. To submit a request for service or information, contact 311.

This form is not intended to collect personal information; however, any personal information you choose to include in your comments is collected by the City of Winnipeg under the authority of section 36(1)(b) of the Freedom of Information and Protection of Privacy Act for the purpose of improving our website and will not be used or disclosed for any other purposes, except as authorized by law. Contact the Corporate Access and Privacy Officer by mail (City Clerk’s Department, Susan A. Thompson Building, 510 Main Street, Winnipeg MB, R3B 1B9) or by telephone (311) if you have any questions about the collection of this information.

Ces renseignements sont-ils utiles?

Comment pourrait-on améliorer cette page Web?

Les renseignements recueillis serviront à l’amélioration de notre site Web. Prière de ne pas se servir de ce formulaire pour soumettre une demande de service ou de renseignements, car la demande ne sera pas transmise au service en question. Pour soumettre une demande de service ou de renseignements, veuillez communiquer avec le 311.

Le présent formulaire ne vise pas à recueillir des renseignements personnels. Cependant, les renseignements personnels que vous choisissez d’inclure dans vos commentaires sont recueillis par la Ville de Winnipeg en conformité avec l’alinéa 36(1)b) de la Loi sur l’accès à l’information et la protection de la vie privée dans le but d’améliorer son site Web et ne seront ni utilisés ni divulgués pour d’autres raisons, sauf dans les cas où cela est autorisé par la loi. Communiquez avec l’agent de l’accès à l’information et de la protection de la vie privée de la Ville par courrier au Bureau du greffier, immeuble Susan-A.-Thompson, 510, rue Main, Winnipeg (Manitoba) R3B 1B9, ou par téléphone au 311 si vous avez des questions sur la collecte de ces renseignements.