Taking care of equipment Cross-contamination can be avoided by
means of several procedures. Sampling activities for example,
shall be performed, as long as possible, following a sequence
from likely least contaminated to most contaminated points.
Furthermore, field staff shall be informed about the origin and
state of all employed equipments or tools, and the use of new
and one-time use components should be encouraged as far as it is
technically and economically feasible. Non-disposable sampling
devices shall be decontaminated before reusing them in the same
sampling campaign or between borehole drillings, and in any case
at the end of field works. These devices, for example, include
electric water-level probes, floating-probes, filters, purging
equipment for monitoring wells, probes of portable measurement
devices (pH meters, conductivity meters, etc.), sampling tubes,
water pumps, augers, etc. After every measurement, electric
(water level measurement) and floating probes (detection and
depth measurement of