Drinking Water Quality Flashcards
What are the main minerals in hard water?
Ca and Mg
Where does hard water get the minerals from?
Rocks and soils it has flowed through via waterways
What are 2 reasons why soft water has a low mineral content?
- Not yet flowed through waterways
- Rocks has come in contact with have little to no soluble minerals
What are the USGS CaCO3 guidelines for soft water, moderately hard water, hard water, and very hard water?
Soft: <61mg/L caCO3
Mod hard: 61-120mg/L
Hard: 121-180mg/L
Very hard: >180mg/L
What % of US homes have at least mod hard water?
75%
What is limescale and what causes it?
Deposits of calcium carbonate, when water is heated or when it sits for too long and minerals solidify as it evaporates
Why you need to remove limescale:
- Causes dull or dry hair
- Irritates sensitive skin
- May cause growth of bacteria in drinking water pipes
- Increased heating costs
- Loss of energy in hot water systems
- Low water pressure
- Dirty looking clothes even if washed twice with detergent
- Frequent replacement or repairs on appliances throughout house
How to remove and prevent limescale:
1) Soften water: buy water softeners which prevent hard water from appearing on surfaces by replacing the Ca and Mg with Na or K
2) Chemical inhibitors: if you have central heating system, ask the plumber to add a specifically designed chemical inhibitor to prevent limescale
3) Carbon filters: softens water and provides clean drinking water, can place filters directly on tap faucet or use jugs
4) Softener tablets: if clothes look dirty after wash, use these to improve the look of the clothes
Is hard water hazardous to human health?
- No known adverse health effect, according to WHO
- Could provide an important supplementary contribution to total Ca and Mg intake
- A protective relationship between hardness of drinking water and cardiovascular disease has been reported in many studies, specifically Mg intake
- Epidemiological studies have shown that dietary Ca is inversely associated with blood pressure
- Water softeners should be connected so that drinking water is not softened
Where does Calgary’s water come from?
- Bow river supplies Bearspaw Water Treatment Plant and the Elbow River flows into the Glenmore Reservoir, which is source for Glenmore Water Treatment Plant
- Bearspaw for north of city and Glenmore for south
- Water is interconnected through large diameter transmission mains to ensure a reliable supply 24/7
- The Bow and Elbow Rivers both feed into the South Sask River, which drains into Lake Winnipeg and eventually Hudson’s Bay
What is the source of water for Bow and Elbow Rivers?
~80% snowmelt and ~20% rain, glacier, and ground
What are the main uses of water from the Bow and Elbow Rivers?
Almost all the water that’s removed from the Bow and Elbow for use in Calgary is returned to Bow River system after treatment in wastewater plants
How hard is Calgary’s water?
Hardness varies seasonally and by location:
- Lowest hardness lvls during spring snowmelt and highest lvls are b/w Dec-Feb
- Bow and Elbow Rivers each have different hardness lvls
Hardness rating in South Calgary?
Avg: 217
Hardness rating in North Calgary?
Avg: 165
