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Water Quality Interpretation
A water supply can be considered unacceptable for drinking purposes based on bacterial analysis; the chemical characteristics of the water such as chlorides, iron and hardness; or the physical characteristics such as odour, taste and colour.The following report indicates the criteria for drinking water quality according to Health Canada's Guidelines for Canadian Drinking Water Quality. For further interpretation of the guidelines, contact the Department of Environment, Labour and Justice at 368-5044 or toll free 1-866-368-5044. The following are notes relating to the guidelines.
(from GCDWQ, Health Canada 1996) |
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| Parameter | Maximum Acceptable Concentration a (mg/L) | Aesthetic Objective b (mg/L) |
| Total Coliform Bacteria | 0 c | |
| E. coli Bacteria | 0 d | |
| Alkalinity Totale | | |
| Barium | 1.0 | |
| Cadmium | 0.005 | |
| Calciume | | |
| Chloride | |  <= 250f |
| Chromium | 0.05 | |
| Copper | | <= 1.0 |
| Iron | | <= 0.3 |
| Lead | 0.01(10ug/L) e | |
| Magnesiume | | |
| Manganese | | <= 0.05 |
| Nitrate (NO3-N) | 10.0 | |
| pH | | 6.5 to 8.5 |
| Phosphorouse | | |
| Potassium | | |
| Sodium | g | <= 200 |
| Sulphate | | <= 500 |
| Temperature | | <= 15oC |
| Total Dissolved Solids | | <= 500 |
| Total Hardness (as CaCO3) | | <= 200 h |
| Zinc | | <= 5.0 |
a Maximum Acceptable Concentration: Drinking water that continually contains a substance at a concentration greater than the maximum acceptable concentration will contribute significantly to consumers' exposure to that substance and may, in some instances, be capable of inducing harmful effects on health.
b Aesthetic Objective: These apply to certain substances or characteristics of drinking water which can affect its acceptance by consumers or interfere with good water supply practices. The aesthetic objective concentrations are below that considered to constitute a health hazard.
c The maximum acceptable concentration for total coliform is 0. If the coliform bacteria count is:
| Less than 10 | Bacteria is present, but not sufficient to regard water unfit for drinking. The results indicate a possible problem with the well. The water should be re-sampled and the source inspected. |
| More than 10 or any E. coli | Water is not considered fit for human consumption. Drinking water should be boiled or an alternate source secured. The water should be re-sampled and appropriate remedial action taken. |
e There is no guideline for this parameter.
f <= less than or equal to
g An acceptable limit for sodium depends on a person's allowable daily intake. If you are on a low sodium diet, see your physician or appropriate health authority. h Public acceptance of hardness varies considerably. Generally, hardness levels between 80 and 100 mg/L (as CaCO3) are considered acceptable; levels greater than 200 mg/L are considered poor, but can be tolerated; those in excess of 500 mg/L are normally considered unacceptable.
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