9) Place bladder pump and tubing in stand-
TCE studies
pipe containing DI water.
Experimental methods
A sample was collected after step 2 was com-
First TCE study--Effect of hot detergent wash on
pleted prior to detergent washing the system. This
bailer. After sampling the well, the bailer was taken
sample was collected to determine if contamina-
to the laboratory and washed as follows:
tion would occur in a system that had been only
1) Remove nylon line and disassemble the
briefly rinsed. Samples were also collected after
bailer.
the system was washed and rinsed and three, six,
2) Place the bailer parts in 4 L of hot (~50C)
and nine system volumes of DI water had been
detergent solution and scrub with a brush
pumped through the system.
(the nylon line was not decontaminated).
After we completed our sampling, the pump
3) Soak for five minutes.
and tubing were disconnected from each other,
4) Rinse bailer parts and wash tub with tap
drained, and placed in an unused laboratory. Af-
water to remove the suds from the deter-
ter allowing the equipment to air dry for one
gent.
week, 6 ft of virgin FEP tubing was attached to
5) Soak in 4 L of hot (~50C) tap water for five
the pump, the pump was placed in the standpipe
minutes.
containing DI water, 58 pump volumes (5 gal.) of
6) Rinse with ambient temperature tap water.
DI water was pumped through the system, and
7) Reassemble the bailer (without the sam-
then a water sample was taken. The bladder pump
pling line).
was then removed from the standpipe, the virgin
8) Rinse by submerging the bailer in DI water
FEP tubing was removed, and the (original) sam-
contained in a 1-L, glass graduated cylin-
pling tubing was reattached to the pump. The
der. Remove the bailer and pour the water
system was then placed in the standpipe contain-
out of the bailer and graduated cylinder.
ing fresh DI water, five system volumes (5 gal.)
Repeat this process two more times.
were pumped through the system, and another
Second TCE study--Effect of hot detergent wash
sample was taken. This was done so that we could
and hot air drying on bailer. In this study, the bailer
separate the amount of contamination from the
was washed and rinsed as described in the previ-
bladder pump vs. the tubing.
ous study and then placed in an oven at 105C
Fourth TCE study--Effect of a wash procedure on
for 24 hours.
pump exposed to low concentrations. The pump used
Third TCE study--Effect of detergent wash on a
in this study had been in a well for over one year.
pump exposed to high concentrations. After remov-
Concentrations of TCE were consistently low. The
ing the pump from the well, the following wash
pump was decontaminated using the same wash
procedure was used:
procedure as the previous study with the fol-
1) Rinse the outside of the tubing and pump
lowing exception. We were able to substantially
as it is withdrawn from the well using the
reduce the volume of rinse water required to re-
pressure washer. Place the rinsed equip-
move all the suds (10 system volumes vs. 75 used
ment on a clean, large plastic sheet.
in the previous study) by running tap water
2) Connect the pump and tubing to the DI
through the pressure washer prior to hooking it
water line and flush three system volumes
up to the sampling pump system. Samples were
of DI water through the system.
collected after three system volumes of DI water
3) Attach the pressure washer to the pump/
were pumped through the system.
tubing.
Fifth TCE study--Effect of EPA wash protocol on
4) Pump 10 system volumes (10 gal.) of hot
pump exposed to high concentrations. Following the
detergent solution through the system.
first study, the pump used in that experiment was
5) Pump 75 system volumes of hot tap water.
placed back in the well, 10 system volumes of
(This large volume of rinse water was re-
well water were pumped through it, and it was
quired to remove all the suds from the
allowed to sit for one week prior to the start of
system.)
this study. In this experiment, a different deter-
6) Disconnect the pressure washer.
gent wash procedure, Procedure 2 given by the
7) Connect the system to a DI water line and
US EPA Region I (1996), was used. This protocol
flush system with three system volumes of
was as follows, with our modifications noted in
DI water.
parentheses:
8) Disconnect DI water line from system.
1) Place the pump inside the wash standpipe.
6
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