Re: Monitoring wells

[Marsden and June Chen <doobage@localnet.com>]

I'll attempt answers to your questions, but please realize that they will be
bare-boned and will be DANGEROUSLY GENERAL.  The answer to your questions
depends on a couple/few realities. 1) Under Superfund or RCRA there usually are
regulatory agencies as the USEPA and a State involved. So while the USDOD is a
federal agency - government - the situation in the vernacular is: two cops
watching another cop(?). There are established protocols for constructing
ground water monitoring wells and there is general agreement on the boring
methods, well casing/screen material (PVC, stainless steel, teflon, fiber
glass) and other materials for the actual constructing a well. EPA and the
States have descriptions available, although many States merely opt for EPA's;
also, you are correct about the text book - there is an excellent reference,
Johnson's Ground Water (?) which contains great "stuff" on well construction.
2) the regulatory agencies have the right to field oversight during well
construction and many times send their engineers, geologists, technicians (EPA
also uses contractors) to ensure that the construction protocols are observed.
Many times the drilling sub-contractor will do a half-baked job if the cops are
not looking over their shoulder. 3) There are also protocols for developing
(jargon for discharging water from the well by mechanical means until an
acceptable turbidity of the water is attained - includes shocking the water
column for clearing out the fines from the sand pack placed around the screen)
the wells and also for sampling them. Typically, the USDOD would be responsible
for "actually monitoring wells" (your Q), but this must be done in accordance
with the established protocols. Lately the USEPA and some States have toyed
with and have been accepting water samples obtained by "low flow" techniques,
i.e., a small tube is inserted down the well and a low volume pump started for
the low flow. The expectation (as shown by some studies) is that  the low flow
will set up a near laminar condition, thereby creating no turbulence or eddies,
etc., and eventually a representative sample will be obtained from the aquifer.
4) Because they are the cops, it is incumbent upon the USEPA the State to
"insure that the monitoring in in fact done" (your Q) - USDOD would be
responsible for the physical moontoring. 5) "who determines how long the wells
need to be monitored?" (your Q) - it depends (mucho "it depends" in the
environmental programs, you'll discover). For RCRA which covers active
facilities, the wells may be used for long term monitoring and sampling could
be done once each quarter or some other period - depends on what the cops want
to measure ( USEPA has released the responsibilities of the RCRA program to
some States - the so called "AUTHORIZATION"). There are some steps under
Superfund - SI - site investigation, RI - remedial investigation, construction
of remedy with long term monitoring. Usually under SI, one round of sampling is
done to determine if contamination or no contamination is found. If  no
contamination is found, we close shop and go home; if contamination is
significant, the program proceeds to the RI under which more wells are
constructed "to determine the areal and vertical extent of contamination" (many
times not enough wells are placed to meet this requirement under the National
Contingency Plan, 40 CFR part 300). One round of sampling is done under the RI
and if significant contamination is found, the program proceeds to selecting a
remedy and long term monitoring. If the single round of samples under the RI
produces questionable data or for some other reason the regulators and USDOD
agree that further rounds are warranted then additional rounds are done. Long
term sampling can extend for years primarily to ensure that the remedy remains
effective - USEPA and the States like the five-year review, (an EPA invention I
think - formerly we used to talk about a 30-year monitoring, but reality has
set in and it is now five), so several rounds of samples could be accomplished
in that time, and if the first five years indicate a continued need, then
monitoring is done for another five and another five and another ...  6) will
find reference and send later - Alzheimers has set in.