1. U.S. Environmental Protection Agency., Quality Criteria for Water. Office of Water and Hazardous Materials Rep. EPA-440/9-76-023, Washington, DC, July 1976.
2. Sekerka, I., and Lechner, J. F., Simultaneous determination of total non-carbonate and carbonate water hardness by direct potentiometry. Talanta 22:459, 1975.
3. Environment Canada., Surface Water Quality in Canada–An Overview. Water Quality Branch, Inland Waters Directorate, 1977.
4. Sawyer, C. N., and Mc Carty, P. L., Chemistry for Sanitary Engineers. 2nd edn. McGraw-Hill Series in Sanitary Science and Water Resources Engineering, McGraw-Hill, Toronto, 1967.
5. Thomas, J. F. J., Industrial water resources of Canada. Water Survey Report No. 1. Scope, procedure, and interpretation of survey studies. Queen’s Printer, Ottawa, 1953.