(b) After the necessary repairs have been completed, chlorinate and
flush the entire system.
(c) Collect samples from representative points throughout the entire
system untiI negative bacteriological results are obtained on at least two consecutive
sets of standard samples collected on different days.
Remove restrictions on the use of water.
c. Condition III (Epidemic). Contaminated samples appear to be associated
with the occurrence of an outbreak of one of the so-called waterborne diseases.
(1) Possible cause. Contamination of the water system at the source, in
reservoirs, in treatment plant faciIities, or in the distribution system, and not generally
apparent at the onset of the outbreak.
(a) Carry out recommendations under Condition I (a, above), with
special emphasis on investigation of the source, reservoirs, treatment processes, and
the distribution system.
(b) Increase the chlorine dosage and residual in the system.
(c) If the conditions contributing to the contamination are found to be
serious, such as a direct contamination with wastewater, reject the supply as in
Condition II and institute emergency treatment (para 6-16a) untiI the condition is
6-16. EMERGENCY PROCEDURES
a. Emergency Treatment. Emergency treatment, as used in this section,
consists of boiIing water for at least 1 minute or maintaining a chlorine residual of at
least 1 ppm and dispensing the water from tanks, trailers, or Lyster bags.
b. Emergency Disinfection. Emergency disinfection, as used in this section,
consists of the removal of indications of contamination from a water supply system by
maintaining a chlorine residual of at least 50 ppm in the affected portion of the system.
Calcium hypochlorite, sodium hypochlorite, or Iiquid chlorine may be used for this
purpose. See chapter 4 TB MED 576 for complete instructions.
6-17. TYPICAL SANITARY HAZARDS
Contamination may occur due to problems at the location of the source of the
water supply, problems in construction, problems in distribution faciIities, or problems in