Water-Quality Field Methods?phaseout of US D-77 and frame-type samplers

In Reply Refer To:
Mail Stop 412
January 25, 2002

Office of Water Quality Technical Memorandum 2002.09

Subject:  Water-Quality Field Methods phaseout of US D-77 and frame-type samplers

The purpose of this memo is to begin the phaseout of the use of the US D-77
rigid-bottle and collapsible-bag samplers and the frame-type bag sampler
for collection of water-quality and sediment samples.  The US D-77
rigid-bottle sampler has been used for many years, although it is known to
be difficult to use correctly because of the very small range in which it
samples isokinetically and because it becomes unstable at relatively low
velocities.  The US D-77 bag and frame-type bag samplers have also been in
use for a number of years; these samplers require field calibration each
time they are used.  The US DH-95, US D-95, and US D-96 isokinetic samplers 
were developed by the Federal Interagency Sedimentation Project (FISP) and 
subsequently approvedby the Interagency Technical Committee of the Subcommittee on
Sedimentation.  These samplers are currently for sale and provide the field
with a well-tested and documented set of samplers that work in most
sampling conditions.   In addition to these samplers, the US XD-99 (275 lb)
is in the testing phase and a lightweight bag sampler is in the design
phase.  The US DH-95 and US D-95 are rigid-bottle samplers with a maximum
sampling depth of 15 feet.  The US D-96 and US XD-99 are collapsible-bag
samplers that have maximum sampling depths of 110 feet and 165 feet,
respectively.  Information about available samplers and ordering samplers
can be found at http://fisp.wes.army.mil/.

The Office of Water Quality, in concurrence with the Office of Surface
Water, is recommending that the US D-77 rigid-bottle and bag samplers and
the frame-type bag sampler be phased out for collection of water-quality
and sediment samples.  As funding permits, these samplers should be
replaced with the newer samplers.  The goal is to replace the discontinued
samplers by the 2003 sampling season.  If the US D-77 is currently being
used, its limitations must be noted.  See Office of Water Quality 
(Technical Memorandum 99.02) and the National Field Manual for Collection of 
Water-Quality Data (TWRI Book 9, Chapter 4.1)) for details on using 
isokinetic samplers.  Instructions for the use of selected samplers can be 
found at http://fisp.wes.army.mil/Reports.htm.

Questions about ordering samplers or the operation of samplers can be
emailed to Wayne O'Neal [woneal@usgs.gov] at the FISP.

                                            Stephen K. Sorenson /s/
                                            Acting Chief, Office of Water
                  Quality

This memorandum supersedes Office of Water Quality Technical Memoranda
81.02 and 90.07.

Distribution:  All WRD Employees
(See attached file: OWQ.0209-D-77.phaseout.doc)

********************************
Stephen K. Sorenson
Acting Chief, Office of Water Quality
U.S. Geological Survey
412 National Center
Reston, VA  20192
703/648-6864
sorenson@usgs.go