| | Water quality criteria | Sodium | Potassium | Calcium | Magnesium | Iron | Sulphate (SO4) | Chloride | NO3 nitrogen (nitrate) | NO2 nitrogen (nitrite) | Fluoride | Total dissolved solids inorganic (TDS inorganic) | Conductivity | pH | Hardness | Alkalinity | Water treatment | Helpful conversions
A routine chemical analysis tests the water for about 15 chemical parameters. Common problems such as hardness, sodium, sulphates, nitrates and nitrites levels can be determined.
Chemicals, other than those discussed below, can be tested, but arrangements should be made with the laboratory before the sample is collected and submitted. These special requests must be arranged before submitting the sample and should be clearly specified on the request form. Special water sample collection procedures may need to be observed.
Your farm water supply should be analyzed regularly, at least whenever a new water source is constructed or when a change in water quality is noticed. Regular testing frequency depends on the type of water source.
To test water for human consumption, your Regional Health Authority can provide the necessary water sample containers and arrange for laboratory testing. Water samples for livestock, irrigation, mortgage approvals, etc. must be sent to a private lab. Check the Yellow Pages telephone book under “laboratories” for lab contacts.
The water sample you take should be representative of the domestic supply. Choose an outlet as close to the source as possible. For most domestic samples, allow the water to run through the faucet for about five minutes and then fill the sample container. Send the sample to the lab as soon as possible.
To help you interpret the results after the laboratory analysis is complete, you can use factsheets, such as this one, or contact a health inspector or agricultural water specialist. The Rural Water Quality Information Tool on Alberta Agriculture’s website (at http://www.agric.gov.ab.ca/app84/rwqit) can also assess water test results for livestock, irrigation, spray water and human drinking water.
The comments on water quality below, which refer to particular minerals/chemicals, pertain to domestic usage.
Water Quality Criteria
It is not legally required for private supplies to meet federal guidelines. People have different reactions and tolerances to different minerals.
Some of the guidelines are “aesthetic objectives” (AO) while others are “Maximum Acceptable Concentrations” (MAC). Aesthetic objectives (AO) relate to effects like taste, odor, staining, etc. MAC levels are assigned when there are known health effects. If a chemical in your water exceeds MAC human drinking water limits, consult your family doctor or local health inspector.
All levels listed below (except pH and conductivity) are listed in milligrams/Litre (mg/L), which is practically equivalent to parts per million (ppm) for drinking water.
Sodium
The AO for sodium is less than 200 mg/L. Sodium is not considered a toxic metal, and normal adults may consume 5,000 to 10,000 milligrams per day without adverse effects. The average intake of sodium from water is only a small fraction of that consumed in a normal diet.
The recommended maximum level for people suffering from certain medical conditions such as hypertension, congestive heart failure or heart disease is 20 mg/L. If in doubt, consult a physician.
Sodium is a significant factor in assessing water for irrigation and plant watering. High levels affect soil structure and a plant’s ability to take up water.
Potassium
There is no guideline or recommended limit for potassium in water. Alberta water supplies rarely contain more than 20 mg/L.
Water softeners that regenerate using potassium chloride can significantly raise the level of potassium in water. It is recommended that people with kidney disease or other conditions such as heart disease, coronary artery disease, hypertension, diabetes and those who take medication that interferes with how the body handles potassium do not drink water from a water softener that uses potassium chloride.
Calcium
The recommended limit for calcium is 200 mg/L; however, there is no federal or provincial guideline. Calcium is one constituent of “hardness” in water. Calcium is generally not a hazard to health, but excessive levels may cause formation of kidney or bladder stones when combined with the calcium ingested in food sources.
Calcium is undesirable because it may be detrimental for domestic uses such as washing, bathing and laundering. It also tends to cause encrustations in kettles, coffee makers and water heaters and may impair treatment processes.
Magnesium
Magnesium is another constituent causing “hardness” in water. There is no federal or provincial guideline for magnesium, but a recommended limit of 150 mg/L is suggested due to taste considertions. Higher levels of magnesium may produce a bitter taste but are not normally a health hazard.
Iron
The AO for iron is less than 0.3 mg/L. Levels as low as 0.2 to 0.3 mg/L will usually cause staining of laundry and plumbing fixtures. Iron gives water a metallic taste that may be objectionable to some at 1 to 2 mg/L. Most water sources contain less than 5 mg/L iron, but occasionally, levels over 30 mg/L are found. The presence of iron bacteria in water supplies will often cause staining even at levels near 0.1 mg/L. Iron and iron bacteria are not normally a health concern.
Iron bacteria cause a slime that can reduce well flow, cause staining, clog up piping and pumps, and impair treatment processes.
A routine chemical test does not always provide a dependable measurement of the iron concentration. A trace metals analysis could be sampled and analyzed if needed to determine a reliable iron level.
Sulphate (SO4)
The AO for sulphate is less than 500 mg/L. Sulphate concentrations over 500 mg/L can have a laxative effect especially to new users and give an objectionable taste. People may become accustomed to higher sulphate levels. If your water contains high levels of sulfate and you suspect that it is causing health problems, you should contact a physician.
Chloride
The AO for chloride is less than 250 mg/L. At levels above 500 mg/L, a salty taste is usually noticeable. Most water in Alberta contains less than 20 mg/L, although chloride in the 2,000 mg/L range can be found in some areas.
NO3 Nitrogen (Nitrate)
The MAC is 10 mg/L when reported as the nitrogen component of nitrate (NO3-N) or less than 45 mg/L when reported as nitrate (NO3).
Nitrates may be an indicator of contamination by human or livestock wastes, excessive fertilization or seepage from dump sites. Nitrates can also occur naturally in some geological formations. The MAC level is largely based on the potential for nitrate poisoning of infants called methemoglobinemia (blue baby syndrome).
NO2 Nitrogen (Nitrite)
Due to its toxicity, the MAC for nitrite in drinking water is 1 mg/L when reported as NO2-N (the nitrogen component of nitrite) or approximately 3.28 mg/L when reported as nitrite (NO2). Nitrite is often an indicator of direct contamination by sewage or manure because nitrites are unstable and quickly converted into nitrates.
Fluoride
The MAC for fluoride is 1.5 mg/L. Levels above this limit may cause dental fluorosis in children 13 years old and younger (even in infants).
Total Dissolved Solids Inorganic (TDS Inorganic)
The AO for TDS is less than 500 mg/L. “Dissolved solids” are small enough to pass through a very fine filter (2.0 microns), and they can come from natural or man-made sources.
The TDS value usually appearing in a lab analysis is calculated from adding the measured mass of all inorganic elements dissolved in water. Alternatively, TDS can be derived from another measurement called “conductivity” and is most accurate when organic content in the sample is low.
Ground water sources often contain higher TDS concentrations than surface water. Average Alberta well water has a TDS level closer to 1,000 mg/L. Levels higher than 1,000 mg/L are not necessarily a problem depending on the specific minerals present. High TDS may be associated with excessive hardness, taste, mineral deposition or corrosion.
Conductivity
Conductivity can be used to estimate the total dissolved solids (inorganic) in the water. Multiplying the conductivity in microSiemens per centimetre by 0.65 will give an approximation of the total dissolved solids in mg/L. Conductivity tests are often used to assess water suitability for irrigation, for which the units used are usually deciSiemens per metre.
1 deciSiemen/metre = 1,000 microSiemens/centimetre
pH
The AO for pH is 6.5 to 8.5. pH is a measure of the concentration of the hydrogen ion, which determines how acidic or basic the water is. The pH scale goes from 0 to 14, with pH less than 7 being acidic and pH greater than 7 being basic. pH below 6.5 may be corrosive whereas pH above 8.5 may cause encrustation, scaling and a bitter taste. The measurement of pH varies with temperature and is usually reported to what it would be at 25 degrees C. pH will affect many water treatment processes and needs to be considered when assessing treatment options.
Hardness
Hardness is caused primarily by calcium and magnesium salts in water. It is expressed as a mg/L equivalent of calcium carbonate. Hard water causes soap curd, which makes bathroom fixtures difficult to keep clean and causes graying of laundry. Increased levels above 100 mg/L will require more soap to be used when washing or bathing.
Hard water will also tend to form scale in hot water tanks, kettles, piping systems, etc.
Most labs will report hardness in mg/L. Many water treatment companies will use field test kits that report hardness in grains per gallon.
one grain per gallon (US) = 17.1 mg/L
| Type of water | Amount of hardness |
 | mg/L | Grains per gallon |
| Soft | 0 - 50 | 0 - 3 |
| Moderately soft | 50 - 100 | 3 - 6 |
| Moderately hard | 100 - 200 | 6 - 12 |
| Hard | 200 - 400 | 12 - 23 |
| Very hard | 400 - 600 | 23 - 35 |
| Extremely hard | over 600 | over 35 |
Alkalinity
Alkalinity is not a specific substance but rather a combined effect of several substances, most importantly carbonates, bicarbonates and hydroxides. It is expressed in units of mg/L of CaCO3. It is a gauge of the ability of water to neutralize acidity. The alkalinity of most Alberta waters is in the range of 100 to 500 mg/L, which is considered acceptable. Water with higher levels is often used. Alkalinity is a factor in corrosion (from low levels) or scale deposition (from high levels) and may also impair treatment processes.
Water Treatment
Water treatment equipment can often improve water quality significantly. Each type of water treatment equipment has its limitations and therefore should be selected carefully. For more information on water treatment please refer to the Agdex 716 D series of fact sheets and the Rural Water Quality Information Tool on Alberta Agriculture’s internet site.
Helpful Conversions
1 mg/L (milligram per litre) = approx. 1 ppm (part per million)
1 gpg (grain per gallon) = 17.1 mg/L (milligram/litre)
References
Guidelines for Canadian Drinking Water Quality – Summary Table (March 2007)
Canadian Environmental Quality Guidelines (Update 6.0 July 2006)
Alberta Environmental Public Health Field Manual http://www.health.gov.ab.ca/resources/publications/Environmental_drinking_water_manual.pdf
Other Information Sources
Alberta Agriculture factsheet regarding livestock water quality Water Analysis Interpretation, Agdex 400/716-2
Rural Water Quality Information Tool link at http://www.agric.gov.ab.ca/app84/rwqit
For further information, contact the Alberta Agriculture and Food agricultural water specialists at:
Alberta Ag-Info Centre toll-free 310-FARM (3276)
Edmonton (780) 427-2963
Lethbridge (403) 381-5846
Red Deer (403) 340-5324
Prepared by
Technology and Innovation Branch
Alberta Agriculture and Food
Source: Agdex 716 (D04). Revised August 2007. |
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