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pH in Water

Where can I find information about pH levels in water?

pH

The symbol pH is used to denote whether a substance is acid, neutral or alkaline. The value of pH can range from 0 to 14. A pH of 1 would be strongly acidic, whereas a pH of 7 would be neutral and a pH of 14 would be strongly alkaline. In Prince Edward Island, well water is usually slightly alkaline with a pH value ranging from 7.0 to 8.5.

The Problem

When the pH drops below 6.5 or rises above 8.3, problems with corrosion or encrustation can occur. Metal corrosion of pipes, distribution lines, well casing etc. becomes more significant below a pH of 6.5.
Acidic water will attack copper piping and plumbing causing a bluish or greenish stain on clothes or fixtures. It can also attack galvanized plumbing and piping causing reddish stains on clothes and fixtures. Acidic water is commonly found in areas where the hardness content is below 60 mg/L.
At a pH above 8.3, encrustation and scaling problems are commonly encountered. This would be more noticeable in hot water lines, heating coils and hot water appliances where whitish or brownish scum or material will be deposited on the surface. High pH alkaline water is usually found in areas with high hardness.

The Solution

Acidic water can be corrected by the following two methods:

Neutralizing Filters
The pH is raised by passing the water through a filter bed of limestone chips (calcium carbonate).
Soda Ash Feeding
Soda ash (NA2CO3) solution is fed through a small tube down the well to the pumping intake and is automatically injected whenever the water pump is running. The pH can be raised to whatever level is desired.

The encrustation or scale buildup caused by alkaline water can be corrected by either of the following methods:

Install a water filter which removes hard water scale or inhibits scale build up.
Install a water softener.

Contact

Charlottetown

Jones Building

Robison, Alan (Senior Drinking Water Technologist)