Water Treatment Basics – Water Sources

(A) How Municipalities Treat Water

Filter visible particles: Clean and reduce physical debris and sediment.
Disinfect for safety: Apply primary and secondary disinfection methods.
Reduce chemical contaminants: Lower chemical and heavy metal levels to strictly meet safety guidelines.
Prioritize public health: Focus municipal treatment efforts primarily on biological and chemical safety.

(B) Primary and Residual Disinfection

Kills disease-causing microorganisms & ensures safe drinking water.
Primary disinfection can be by chlorine, UV, membranes etc.
However, because municipal water must travel through extensive pipe networks, it is susceptible to re-contamination. To prevent this, a residual disinfectant is added to maintain safety during distribution—a process known as secondary disinfection.

(C) Primary Disinfection – Chlorination

Chlorine is the most common chemical used for water disinfection in Canada because:
- Chlorine is effective against a wide range of microbiological contaminants
- Chlorine remains in the water throughout its journey through the extensive distribution system, ensuring safety from the treatment plant to your home
- It is highly cost-effective and widely available
- It is very effective against microbes
Chlorine renders an unpleasant taste and odour to water, which negatively affects the flavour of beverages and can be harmful to sensitive plants and aquatic life.
Some individuals experience heightened chemical sensitivity or skin irritation from exposure to chlorinated water.

(D) Primary Disinfection – Chloramination

When chlorine reacts with naturally occurring organic matter, it can form harmful disinfection byproducts known as TRIHALOMETHANES (THMs), which are potentially carcinogenic. To mitigate this risk, municipalities introduce ammonia to the water supply—a stabilization process known as chloramination.
Chloramination results in the formation of “Chloramines”. (CHLORine + AMMonia)
As a disinfectant, chloramine is less potent than chlorine and therefore requires a significantly longer contact time to achieve the same level of pathogen inactivation.
Chloramines are corrosive, toxic to fish and can impart a distinct taste and odour your water. The long term effects of chloramines on human health are still under study.

Dug Wells

Designed for individual or small communal applications.
Shallow hole in the ground, sometimes covered with concrete or other slabs, but most commonly left uncovered.
Susceptible to surface runoff, debris (such as dirt, mud, and leaves), and wildlife infiltration (including bacteria, insects, and rodents).
Generally low in dissolved minerals.
What to expect – Generally low in mineral content, but high possibility of bacteria, cyst or fertilizer contamination. Affected by seasonal changes and can be high in suspended dirt.

Lake or River water

Sourced directly from surface water bodies such as lakes and rivers.
High vulnerability to pathogenic bacteria and cyst contamination.
Subject to seasonal fluctuations, often resulting in high turbidity (suspended sediment).
Prone to elevated tannic acid levels caused by decaying leaves and vegetation.

Drilled Wells

Constructed by professional well drillers.
Properly covered and protected from insects, rodents, and run-off.
Contamination can still occur from animal waste, fertilizer use etc.
Due to well depth, they can be high in dissolved minerals such as hardness or iron
What to expect – Generally higher in mineral content (hardness, iron, TDS etc.), but generally stable water quality that is unaffected by seasonal changes.

How are wells connected to homes

Drilled wells usually have SUBMERSIBLE pumps (inside the well).
Pumps are connected to a pressure tank which has a pressure switch.
When pressure drops in the tank to a certain point (CUT-IN), the switch signals the pump to come on.
When the tank is full again, pressure increases (CUT-OUT) and well pump switches off.
Most pumps operate between 30 – 50 psi, but this is generally adjustable.

What is Water Flow Rate and Water Pressure

Flow rate is the volume of water that flows through a pipe in a second.
- Measured in gallons per minute (GPM) or LPM
- Imagine a highway – flow rate would relate to how many cars are moving in a second
Pressure is the force required to move the water.
- Measured in psi, Kg/cm2, or kPa (Kilo Pascals)
- Imagine a highway – pressure would be how fast the car is moving
You can have a high water flow with low pressure (like a river), or conversely, very low flow with extremely high pressure (like a pressure washer).

Well Pump Flow Rate

This is the amount of water that the well pump pushes to the pressure tank in 1 second.
- Measured in GPM (Gallons per minute or Liters per minute)
This is different from “Well Recharge Flow Rate” – this is how quickly the well fills up with water once the pump stops