Where does our water come from?

City of Lethbridge water comes from the Oldman River.  A river is referred to as a surface water supply.  Our treatment plant processes raw river water, to make safe healthy drinking water.  The plant site is on the east bank of the river, south of Whoop-up Drive, and across the river from the university.  We treat an average of about 50 million litres of high-quality drinking water on a daily basis.  The maximum daily production was 120 million litres.

How is the water treated so you can drink it?

Like many water utilities with a surface water supply, we use a multi-step treatment process consisting of the following:
1. Addition of approved treatment water treatment chemicals to changes very  small  particles and other contaminants into larger particles (big enough to see). Coagulation.
2. The majority of these larger particles are removed from the water by settling them in tanks called clarifiers. This process is called Sedimentation.
3. The "settled" water is then filtered to remove the remaining particles to thousandths of a millimeter (too small to see). Filtration.
4. Fluoride ion is added to the water as a benefit the community's dental health.  Lethbridge has added fluoride to the drinking water since 1972.
5. Disease-causing organisms (bacteria, viruses, etc.) that haven’t been removed by filtration are then “killed” with chlorine and by ultraviolet light (UV).  We then combine the chlorine with ammonia to form chloramine.  This reduces the formation of chlorine by-products, and helps it last longer to continue protecting your water on its journey to your home tap. (Disinfection)

How hard is our water?

The hardness of Lethbridge water varies and is highest in the winter.  It typically ranges from 140 milligrams per litre (about 8 grains per US gallon) to 210 milligrams per litre (about 12 grains per US gallon).

How often is the water tested to assure its quality?

The certified operators at the treatment plant completed about 28,000 tests as part of their daily routine in 2007.  Nearly 1,200 bacteria tests were performed by the Provincial Public Health Laboratory on samples collected each week from throughout the water distribution system.  Each month a treated water sample is sent to a commercial laboratory for some 30 different analysis, like metals and disinfection by-products.  And finally, at least twice each year treated water samples are subjected to a scan of 150 organic compounds including pesticide chemicals, as well as over 50 tests for metals and other more routine analysis.  In total, over 30,000 tests were conducted on our drinking water in the year 2007.

How does our water quality measure up?

Lethbridge drinking water consistently exceeds regulated requirements established by Health Canada in the "Guidelines for Canadian Drinking Water Quality", and the specific requirements within our Approval from the Province of Alberta under the Environmental Protection and Enhancement Act.

What is our water pressure?

Our water distribution system is designed and operated to deliver a minimum acceptable pressure delivered to each Lethbridge service connection of no less than 300 kilopascals (45 psi) during peak hour demand, and 350 kilopascals (50 psi) at maximum day demand.  The maximum pressure should not exceed 625 kilopascals (90 psi).