Environmental Engineering Reference
In-Depth Information
China
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indicates that the following measures are feasible (and can be made as
requirements through codicils in the financing loan agreement):
(a) Insist on use of chlorination sufficient to produce a measurable residual at
the household taps, including weekly monitoring of a selected number of
taps (which is easily done using simple colorimetric instruments) (Measure
coliforms much less frequently, say at 3-month intervals). To this end,
promote use of elevated storage tanks in the UWSS for maintaining pressure
in the distribution system, instead of pressure pumping, so that the storage
tank can be used for easy chlorination of the supply, preferably by use
of sodium hypochlorite powders. If gaseous chlorine must be used, utilize
safety protection systems as specified in publications of the American Water
Works Association, to prevent injury to O&M personnel.
(a.1) People in some DCs, especially in Asia, commonly boil their drinking
water; hence, the argument may be made that chlorine disinfection
is not needed. It is nevertheless needed, especially because children,
when away from the home, are prone to drink water from any avail-
able tap, regardless of instructions from parents.
(a.2) Some UWSS officials are confused by the attention in the interna-
tional media on THMs in chlorinated water and use of disinfection
by methods other than chlorination. The reality in the DCs is quite
different from that in the ICs. In the DCs, a person's chances for
growing old will be greatly diminished if he or she drinks nondisin-
fected water, and the only disinfection method feasible for almost all
DC cities is chlorination.
(a.3) Encourage local organizations, like the Boy Scouts, to do the routine
chlorine residual testing, as a public service, in recognition that most
DC municipalities will be reluctant to fund this service.
(b) Insist on a salary level sufficient to attract and keep and a competent UWSS
manager and furnish him with adequate staff and training materials and
training opportunities, and require meaningful periodic reports on system
performance (including management of complaints).
(c) Encourage use of quality materials and equipment in order to minimize
“holes” in the distribution system.
(d) Try to achieve a design for the overall UWSS that will maintain positive
pressures in the system at all times.
(e) Encourage addition to the UWSS staff of an engineer trained in sanitary/public
health engineering as the most practical way for incorporating the sani-
tary/public health engineering parameter into the “mindset” of the UWSS
organization, including establishment of a reliable water quality testing lab-
oratory. The need and value for this is illustrated in the paper on this subject
as presented in Box 4.1 in the Subsection, “Water Quality Analyses.”
(f) Make effective use of private sector, either for turnkey projects or only
for O&M, with feasible attention to use of water charge rates acceptable
