MIL-HDBK-1005/7A
Drinking Water Regulations. Refer to Water Treatment Plant
Design, Chapter 10, "Oxidation and Disinfection," AWWA, third
edition, for additional information relating to disinfection
requirements.
6.7
Disinfection . Refer to Water Treatment Plant Design,
Chapters 10, "Oxidation and Disinfection," Chapter 15,
"Chemicals and Chemical Handling," AWWA, third edition; Water
Quality and Treatment, Chapter 14, "Disinfection," AWWA, fourth
edition, AWWA Manual M20, Water Chlorination Principles and
Practices ; and Recommended Standards for Water Works, Part 4.3
and Part 5; Health Science Group, 1997 edition. Disinfection
should be in accordance with all regulations (including CT) as
published in the 40 Code of Federal Regulation (CFR) Part 141.
6.7.1
Well Disinfection . Refer to AWWA Manual M21,
Groundwater, AWWA Standard A100, Water Wells; and AWWA Standard
C654, Disinfection of Wells , for well disinfection requirements.
6.8
Softening
6.8.1
Softening Processes. Refer to Water Treatment Plant
Design, Chapter 11, "Lime Softening," and Chapter 12, "Ion
Exchange Processes," AWWA, third edition, for detailed design
criteria. For general design criteria refer to Recommended
Standards for Water Works , Part 4.4, Health Education Services,
1997 edition.
6.8.2
Design Features. The most desirable total hardness
for potable water supplies is about 100 ppm, with a carbonate
hardness not less than 40 ppm. Water softer than 100 ppm total
hardness is often corrosive. For water used only for domestic
purposes, excessive hardness causes increased usage of soap and
decreased lifetime of water heaters. There is no recognized,
unacceptable upper limit for hardness, and the decision to
soften can be based on economic analysis, consumer preference,
or the judgment of the designer. The health effects of added
sodium should be considered in evaluating any water softening
program.
For a boiler water conditioning, hardness requirements
and softening techniques are discussed in MIL-HDBK-1003 Series.
6.9
Special Treatment
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