PUBLICATIONS--Statement Regarding Dissolved Trace-Element Data Production Through Water Year 1991



In Reply Refer To:                            January 28, 1992
Mail Stop 412


OFFICE OF WATER QUALITY TECHNICAL MEMORANDUM NO. 92.03

Subject:  PUBLICATIONS--Statement Regarding Dissolved 
          Trace-Element Data Production Through Water Year 1991


Over the last 3 years, the Office of Water Quality has initiated 
a process to evaluate the production of operational program 
dissolved trace-element data.  Because data produced through 
water year 1991 may exhibit unacceptable influences of 
contamination for some elements, a paragraph has been prepared 
for inclusion in the State annual data reports.

The prepared paragraph is short and does not contain quantitative 
information for two reasons:  first, there are no quality control 
(QC) data; and second, contamination can be from many sources and 
can be either random or systematic.  The recent evaluation 
studies have attempted to identify some of the systematic 
contamination sources existing today.  This information is not 
intended to quantify the level of contamination at individual 
sampling sites, but is instead intended to guide the elimination 
of identified contamination sources.  

The paragraph does not identify specific "problem" trace 
elements, as did Office of Water Quality Technical Memorandum 
91.10.  This type of listing is not appropriate for a generic 
statement because data in the annual reports come from many 
sources, including projects that may have used good cleaning 
procedures and other procedures to produce data at the microgram 
per liter (ug/L) level without significant contamination.  Thus, 
a listing of "problem" trace elements could be misleading 
because: (1) data were produced from many sources with varying 
levels of contamination, and (2) data for any element not 
included on the list would be assumed to be "clean," but using 
existing protocols, this could be incorrect.

Even with increased QC for water-quality programs across the 
Division, we will not be able to quantify adjustments to historic 
data that can be made for specific elements at specific 
locations.  However, what we are doing is establishing a process 
to improve trace-element sample results at the ug/L quantitative 
level.  That process includes the following: (1) certify specific 
sampling equipment for use, (2) provide explicit protocols for 
the preparation and cleaning of equipment and for sample 
processing, (3) initiate training for field personnel in using 
the protocols, and (4) implement adequate QC to maintain a high 
level of confidence in trace-element data quality.  The final 
step in this process is important because random sources of 
contamination may affect the data even when the equipment and 
protocols are properly used.  This process should be established 
during water year 1993.

The preceding background information leads to the statement below 
for inclusion in State annual data reports.  Please include the 
statement in State annual data reports for 1991:

    "Traditionally, dissolved trace-element concentrations 
    have been reported at the microgram per liter (ug/L) level.  
    Recent evidence, mostly from large rivers, indicates that 
    actual dissolved-phase concentrations for a number of trace 
    elements are within the range of 10's to 100's of nanograms 
    per liter (ng/L).  Present data above the ug/L level should 
    be viewed with caution.  Such data may actually represent 
    elevated environmental concentrations from natural or human 
    causes; however, these data could reflect contam-ination 
    introduced during sampling, processing, or analysis.  To 
    confidently produce dissolved trace-element data with 
    insignificant contamination, the U.S. Geological Survey will 
    begin using new trace-element protocols in the near future."




                               David A. Rickert
                               Chief, Office of Water Quality


Key Words:  Water quality, annual reports, trace elements

This memorandum does not supersede any previous Office of 
Water Quality Technical Memorandum.

Distribution:  A, B, S, FO, PO