MIL-HDBK-1164
d)
Drilled Wells. Drilled wells require little maintenance on casings.
Screens can become clogged and will require periodic cleaning. Inspecting or
removing the screen requires a major effort. Cleaning the screen in place is the
preferred method (see par. 4.5.3.1). Alternatively, remove, clean, and replace the
screen.
e)
Gravel-Packed Wells. Both the gravel and screen may become
clogged in a gravel-packed well. Add gravel periodically to keep the gravel level above
the well screen.
4.5.3.4
Maintaining Springs. Springs are subject to surface contamination.
Inspect the area around the spring regularly to detect contamination and guide
preventive measures for contamination control. If contamination is detected,
thoroughly disinfect the spring before returning it to service.
4.5.3.5
Maintaining Infiltration Galleries. In addition to silt accumulation,
undermining of walls and failure of the wall structures may occur. Operating records on
static level and drawdown will indicate whether the yield is being maintained.
Maintenance functions that can increase the life of the structure include cross bracing,
adding sheet piles, and adding gravel. Yield can sometimes be increased by driving
wells in the bottoms of the galleries.
4.5.3.6
Maintaining Radial Wells. Shallow radial water collectors may be subject
to contamination from overlying ground pollution. In some locations, silt or sand may
accumulate in the caisson and require removal. Dewater the collector well and gunit
the surface if spalling of concrete walls is severe.
4.5.4
Protection of Groundwater Supplies. A number of state and national laws
protect aquifers. Wellhead protection programs (WHPP) are local mandates. The
publications in pars. 2.1.3 and 2.2.1 discuss these and other aspects of groundwater
protection.
4.5.4.1
Protection against Contamination through Improper Operation. Guard
against pollution through improper operation of well supplies by following these steps:
a)
Always prime the pump with potable water.
b)
Disinfect the pump and drop pipe before installation and after any
repair. Disinfect the equipment as it is lowered into the well.
Note: Give particular attention to the disinfection of the pump packing.
Ridding this particular area of bacteria can be difficult.
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