the initial yield of the well, and these data can be used for periodic redevelopment and

maintenance assessments.

If well drilling, installation, or completion have altered ground water quality

chemically in the vicinity of the well, well development should aid in restoring ground water

quality within the well to natural ground water quality. The ability of a well development

method to remove clays from the sides of the borehole should be considered, because clays

retained in the borehole may alter the chemical composition of ground water in the well. The

Agency recommends periodically monitoring ground water during well development for water

quality parameters such as specific conductance and pH. The reproducibility of water quality

results provides some indication that ground water chemistry in the well has been restored to

natural quality. In general, the Agency also recommends that the volume of water introduced

into the well during well drilling, installation, and completion be withdrawn from the well

during well development. The volume of water withdrawn from a well during development

should be recorded.

6.8

Documentation of Well Design, Construction, and Development

Information on the design, construction, and development of each well should be

compiled. Such information should include: (1) a boring log that documents well drilling

and associated sampling, and includes the minimum required information presented in Table 3

and Section 4.2.1; and (2) a well construction log and well construction diagram ("as built").

The well construction log and well construction diagram should present the following

information (including dimensions, as appropriate):

Well name/number;

Date/time of well construction;

Borehole diameter and well casing diameter;

Well depth ( 0.1 ft);

Casing length;

Casing materials;

Casing and screen joint type;

Screened interval(s);

Screen materials;

November 1992

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