Water resource investigators must not only focus on
assessments of the location, quantity and availability of
water but also determination of water quality. The quality
of a particular body of water, whether stream, river, lake
or estuary can be assessed by examining the physical,
chemical and biological characteristics. These parameters
can be evaluated based upon sampling both the water
itself, the sediments and aquatic life supported by the
body of water being examined.
The instrumentation and samplers in this section are of
standard use by the USGS, EPA and other federal and state
agencies as well as international standards for testing as
set forth in the ISO guidelines. To provide data for
planners, developers, water-quality managers and
pollution-control agencies, a high degree of reliability
and standardization of this data is of paramount
importance.
The instrumentation can be categorized into water
quality samplers such as the Kemmer, horizontal and
vertical Van Dorn water bottles, benthos samplers such as
Ekman, Ponar and Van Veen, substrate samplers such as
Hester-Dendy and periphyton, standard hand cores
Kajak-Brinkhurst (K-B) and gravity tube cores and flowing
water aquatic samplers such as the Surber, Hess and drift
net.
Physical and chemical characteristics can be evaluated
by instruments that continuously monitor and record these
properties or by spot checks when the hydrologist is
actually on-site making measurements. These samplers will
collect water or sediment samples for examination in the
lab or on-site with various tests. Water quality meters
can be used on-site with the data recorded for later
analysis.
Samplers used for biological parameter assessment
include periphyton, benthic macroinvertebrates and fish.
