the operation of the system. In determining the cause of contamination of a water
supply, the investigator may be guided by the following examples of typical sanitary
hazards.
a. Surface Water Supplies
(1)
Location.
(a) Lack of supervision of the water shed area. Unrestricted use for
recreational purposes, habitation, and industry.
(b) Water treatment plant and faciIities situated in an area subject to
(c) Sewers, cesspools, latrines, dumps, sanitary fills, or other sources
of contamination situated in the vicinity of the various units of the treatment plant.
(d) Improper location of the water intake with respect to the bottom of
the body of water, and nearby drainage outlets, natural currents, winds, and tidal action.
(2)
Construction.
(a) Common wall (construction) used between treated and raw water
units.
(b) Bypass connections for raw and partially treated water whereby
such waters may be discharged into distribution system.
(c) Manhole openings into collection reservoir are not provided with
raised siII and overlapping covers.
(d) Vents not properly screened or otherwise protected to prevent the
entrance of contaminating materials.
(e) Pumping equipment situated in subsurface pumproom subject to
(3)
Operation.
(a) Operator not trained in the fundamental principles of water plant
operation.
(b) Operating equipment such as chemical feeders and chlorinators
are allowed to become inoperative and are not repaired.
MD0160
6-23