(e) When a water-bearing formation of poorer quality is penetrated, the
formation should be sealed off to prevent the infiItration of water into the well and the
(3) Disinfection. All newly constructed wells should be disinfected to
neutralize contamination from equipment, material, or surface drainage introduced
during construction. To properly disinfect a well, sufficient calcium hypochlorite should
be added to provide a concentration of 50 ppm (approximately 1 ounce of dry chemical
per 100 gallons of water) (1 ounce of calcium hypochlorite per 100 gallons of water in
the well hole) and allowed to remain in the well for 24 hours. Care should be taken to
disinfect the sides of a dug well with a brush or broom and to disinfect the interior of a
pump by pumping water through it untiI the odor of chlorine is detected. After 24 hours
have elapsed, the pump should be operated untiI the water is free of chlorine odor.
a. Development. There are two important considerations in the development of
a spring: the quantity of water available and the protection of the sanitary quality.
Development of a spring inlet includes the following (see figure 5-1):
(1) An open-bottom, watertight basin intercepting the source and extending
to bedrock or a system of collection pipes and a storage tank.
A cover that prevents the entrance of surface drainage or debris into the
Provision for the cleanout and emptying of the tank contents.
Provision for overflow.
(5) A connection to the distribution system or auxiIiary supply.
b. Sanitary Protection of Springs. Springs usually become contaminated
when barnyards, sewers, septic tanks, cesspools, or other sources of pollution are
located on higher adjacent land. The following precautionary measures wiII help to
maintain developed spring water of a consistently high quaIity.
(1) Provide for the removal of surface drainage from the site. A surface
drainage ditch located at least 50 feet away on the uphiII side of the spring will prevent
contaminating material from entering the source.
(2) Construct a suitable fence at least 100 feet from the water source to
prevent entry of Iivestock. The drainage ditch should be inside the fence at all points
uphiII from the source.