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Water Disinfection Practices in the United States
Author(s) -
Laubusch Edmund J.
Publication year - 1960
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.1960.tb00613.x
Subject(s) - safe drinking water act , water quality , quality (philosophy) , publication , public health , state (computer science) , water treatment , business , environmental science , environmental health , environmental protection , environmental engineering , medicine , mathematics , ecology , philosophy , nursing , epistemology , algorithm , advertising , biology
Chlorine disinfection has been firmly established in the United States over the past 50 years, and there is a trend toward its adoption as a minimum safe‐guarding treatment for all public surface water supplies. Except for water used on interstate carriers, authority for control of public water supplies is vested in the various states and their political subdivisions. The degree to which authority is exercised varies considerably among the states, but U.S. Public Health Service (USPHS) standards of quality almost invariably serve as minimum indexes of bacteriologic safety. At least 30 states publish minimum standards for water treatment plant design, operation, and maintenance. Ten of these, and six additional states that do not publish them, have adopted the Ten‐State Standards, in whole or in part, as the basis of their minimum recommendations or requirements. Among the remaining states, no uniform criteria are apparent. Not all states require disinfection of all public surface and groundwater supplies, but at least 30 states require or recommend chlorine disinfection of surface waters regardless of raw‐water quality. Additionally, at least twelve states specify chlorination as needed to comply with bacteriologic quality standards of USPHS. Only a few states have fixed policies with regard to points of chlorine application, minimum contact periods, and residuals obtained. Apparently, health authorities usually relate these to local conditions and treatment objectives. Almost invariably, the critical test of suitable water disinfection is the demonstration of freedom from coliform organisms according to prescribed test procedures. No state authorities define water quality in terms of residual chlorine content, and only a few apparently have rigid policies on the frequency of tests for residual chlorine. Only a few states define minimum capacity of chlorinating equipment, but 80 per cent of the states known to publish minimum standards or otherwise to have adopted the Ten‐State Standards provide for installation of adequate standby chlorinating equipment to insure continuity of operation during emergencies.