Summary of Canadian Drinking Water Quality Guidelines​
Category
Parameter
Definition / Health Concern
​Common Source
​Guideline
Microbiological
 
 
 
 
 
​Total Coliforms
Type of Bacteria that are present in the digestive system of animals and humans
Human and animal feces, naturally occurring in water, soil and plants
​MAC <1
 
​E. coli
Type of Bacteria that are present in the digestive system of animals and humans
​Human and animal feces
​MAC <1
Metals
 
 
 
 
 
Aluminum
​Type of metal/ no consistent evidence that Aluminum causes diverse health effects in humans
​Aluminum salts used as coagulants at water treatment plants, naturally occurring
​OG<1 mg/L
 
Antimony
Type of metal/ Microscopic changes in organs and tissues ​
​Naturally occurring soil runoff, industrial effluents, leaching from pipes
​MAC=0.006 mg/L
 
Arsenic
​Type of metal / Carcinogenic
​Naturally occurring, released from mining or Industrial effluents
​MAC=0.01 mg/L
 
Barium
​Type of metal/increases blood pressure, cardiovascular disease
​Naturally occurring; releases or spills from industrial uses
​MAC=1 mg/L
 
Boron
​Type of metal/ Reproductive effects
​Naturally occurring; leaching or runoff from industrial use
​MAC=5 mg/L
 
Cadmium
​Type of metal/ kidney damage and softening of bone
​Leaching from galvanized pipes, solders or black polyethylene pipes, industrial and municipal waster
​MAC=0.005 mg/L
 
Calcium
​Type of metal
​Naturally occurring
​NA*
 
Chromium
​Type of metal/skin irritation
​Naturally occurring, releases or spills from industrial uses
​MAC=0.05 mg/L
 
Cobalt
​Type of metal
​Naturally occurring
​NA
 
Copper
​Type of metal ,essential element in human metabolism
​Naturally Occurring, leaching from copper piping
​AO ≤ 1 mg/L
 
Iron
Type of metal
​Naturally occurring, landfill leaching, Sewage effluents
​AO ≤ 0.3 mg/L
 
Lead
​Type of metal/ Neurobehavioral effects in infants and children under the age of 6, Anemia, classified as a carcinogen to humans
Leaching from plumbing (pipes, solder, brass fittings and lead service lines)
​MAC=0.01 mg/L
 
Magnesium
​Type of metal
Naturally occurring
​NA
 
Manganese
Type of metal
Naturally occurring
​AO: ≤ 0.05 mg/L
 
Mercury
​Type of metal/ neurological symptoms
​Released from industrial spills, waste disposal, agricultural pesticides drainage
​MAC=0.001 mg/L
 
Molybdenum
Type of metal
​Naturally occurring
NA
 
Nickel
Type of metal
​Naturally occurring
​NA
 
Potassium
Type of metal
​Naturally occurring
NA
 
Selenium
Type of metal/ chronic selenosis symptoms following high exposures
Naturally occurring, released from coal mines
MAC=0.05 mg/L
 
Silver
Type of metal
​Naturally occurring
NA
 
Sodium
Type of metal
Naturally occurring, seawater intrusion , sewage and industrial effluents, sodium base water softeners
AO ≤200 mg/L
 
Uranium
Type of metal/May cause kidney effects
Naturally occurring, mill tailings, erosion from nuclear industry and coal combustion, and phosphate fertilizers
MAC=0.02 mg/L
 
Zinc
Type of metal
Naturally occurring industrial and domestic emissions, leaching from galvanized pipes, hot water tanks and brass fittings
​AO ≤5 mg/L
Anions
 
 
 
 
 
Chloride
Naturally occurring Anion
Naturally occurring (seawater intrusion), dissolved salt deposits, oil well operations, sewage and irrigation drainage
AO ≤250 mg/L
 
Fluoride
Naturally occurring Anion/ beneficial in preventing dental decay
Naturally occurring (rock and soil)
MAC=1.5 mg/L
 
Nitrate
Naturally occurring Anion/ classified as possible carcinogen, may cause Methaemoglobinaemia and effects on thyroid gland function in bottle fed infants
Naturally occurring, leaching or runoff from fertilizer, manure, and domestic sewage. May also be produced from excessive amounts of ammonia or nitrification in the distribution system
MAC=10 mg/L
 
Nitrite
As Above
As Above
MAC=1 mg/L
 
Sulfate
Naturally occurring minerals overtime are dissolved and released into groundwater/May cause diarrhea and dehydration
Industrial waste
AO ≤500 mg/L
General Parameters
 
 
 
 
 
Alkalinity
Measurement of CaCO3 mineral in water, once precipitated they can form into scale which can block pipes and affect the performance of household items
Naturally occurring (rock erosion and runoff from soil)
NA
 
Colour
Measurement of the apparent colour of water which is compared to a series of standards
Naturally occurring organic substance, metals, and industrial waste
AO ≤15 CU
 
Conductivity
Measures concentration of ions in water.
Conductive ions come from dissolved salts, chlorides, sulfides and carbonate compounds
NA
 
Cyanide
Carbon-nitrogen chemical/ short term effect: rapid breathing and neurological effects ; long term effects: weight loss, thyroid effects, and nerve damage
Industrial and mining effluent, released from organic compounds
MAC=0.2 mg/L
 
pH
Measurement of the negative logarithm of the hydrogen ion activity in water at a give temperature
6.5-8.5
 
Turbidity
Measurement of cloudiness or haziness of water
Naturally occurring particles
OG <0.1 NTU
Calculated Parameters
 
 
Value
 
 
Hardness
Measurement of CaCO3
 
NA
 
Total Dissolved Solids
Measurement of dissolved solids in water. TDS above 500mg/L results in scaling in pipes, heaters, boilers and other household appliances
Naturally occurring solids, urban and agricultural runoff, industrial wastewater
AO ≤ 500 mg/L
*MAC= Maximum Acceptable Concentration
*OG=Operational Guideline (treated water)
*AO= Aesthetic Objective
*NA= Not Regulated
Source:
Health Canada: Canadian Drinking Water Guidelines- http://www.hc-sc.gc.ca/ewh-semt/water-eau/drink-potab/guide/index-eng.php