SEDIMENT CHEMISTRY--Contamination from D-77 Samplers Equipped with Solenoid-Actuated Valves  


In Reply Refer To:                       February 2, 1990
WGS-Mail Stop 412



OFFICE OF WATER QUALITY TECHNICAL MEMORANDUM 90.07

Subject:  SEDIMENT CHEMISTRY--Contamination from D-77 
                              Samplers Equipped with 
                              Solenoid-Actuated Valves

The Office of Water Quality currently is sponsoring a study 
of possible trace-metal contamination associated with various 
water and suspended sediment samplers used by Water Resources 
Division personnel.  The study shows that the D-77 sampler 
equipped with a solenoid-actuated valve contaminates samples 
with metals, including iron, lead, copper, zinc, and cadmium.  
Therefore, anyone requiring analyses of trace metals, either 
dissolved or associated with suspended sediments, should not 
use a D-77 sampler equipped with a solenoid-actuated valve.

John Skinner of the St. Anthony Falls (Minnesota) Hydraulic 
Lab has developed a modified sampler to obviate this problem, 
but it has not yet been tested and evaluated under field 
conditions.  Arthur Horowitz of the Georgia District will 
evaluate the efficacy of the modified sampler with respect to 
avoidance of trace-metal contamination.  As soon as the 
results are available, they will be reported in a subsequent 
Office of Water Quality Technical Memorandum.  

The standard D-77 sampler without the solenoid-actuated valve 
still may be used for all applications.  The few D-77 
samplers with the solenoid-actuated valve still may be used 
for those applications that do not call for trace-metal 
analyses.  

Any questions about D-77 sampler contamination should be 
directed to Sidney Johnson, Office of Water Quality, 
FTS 959-6808.




                             David A. Rickert
                             Chief, Office of Water Quality

This memorandum does not supersede any OWQ Technical 
Memorandum.

Key Words:  Contamination, Trace Metals, Samplers, 
            Water Quality

Distribution: A, B, PO, FO 
              John Skinner
              Arthur Horowitz 
              Project Office, Vancouver, Washington