A National Quality Assurance Program for Sediment Laboratories Operated or Used by the Water Resources Division

To: "A  - Division Chief and Staff",
        "B  - Branch Chiefs and Offices",
        "FO - State, District, Subdistrict and other Field Offices",
        "PO - Project Offices"
cc: " , WRD Archive File, Reston, VA ",
        "L. Jane Rose, Secretary, Reston, VA "
Subject: Office of Surface Water Technical Memorandum No. 98.05
Date: Mon, 16 Mar 1998 16:00:06 -0500
From: "L. Jane Rose, Secretary, Reston, VA "

In Reply Refer To:
Mail Stop 415                                              March 2, 1998


Subject:  A National Quality Assurance Program for Sediment Laboratories
          Operated or Used by the Water Resources Division


This memorandum describes the components of a national program to quality 
assure sediment data produced by laboratories operated or used by the U.S. 
Geological Survey, Water Resources Division (WRD). The objective of this 
National Quality Assurance Program for Sediment Laboratories is to ensure that 
physical sediment data produced or used by the WRD are of a known and 
documented quality, and are sufficient to provide long-term data comparability 
and consistency on a national basis.  Full participation in this program is 
required for WRD sediment laboratories, and for other laboratories that 
provide sediment data used by the WRD.

It is the program's intent to be responsive to the needs of the 
participating laboratories, Districts, thrust programs, and the Offices of 
Surface Water (OSW) and Water Quality (OWQ).  To this end, the program 
undoubtedly will evolve.  The OWQ's Branch of Quality Systems (BQS), in 
conjunction with the above will be responsive to the needs of each group and 
accommodate their needs to the fullest extent possible.

This program combines and augments several existing quality-assurance 
activities to provide quantitative information on sediment-data quality to 
sediment laboratory customers.  Its focus is on all quantitative analyses done 
on water-sediment mixtures to derive concentrations, sand/fine splits, and 
particle-size distribution completed by the visual accumulation tube and 
sieve/pipette, Sedigraph, and bottom withdrawal methods.  It also includes on-
site qualitative reviews of sediment laboratory operations, procedures, and 

The program is comprised of the following components:

  o  Training in laboratory operational procedures 
  o  On-site laboratory evaluations 
  o  A single-blind reference sediment-sample project
  o  A double-blind reference sediment-sample project
  o  Data analysis and reporting for each laboratory and on a national basis
  o  Follow-up evaluations
  0  Documentation of laboratory quality-assurance plans and quality
     control procedures


In accordance with OSW Technical Memorandum No. 91.11, "Certification Training 
for Sediment Laboratories," each WRD District or contract sediment 
laboratory chief (the individual from the District or contract laboratory 
responsible for the quality of laboratory results) must complete WRD 
certification requirements.  The policy specifies that in order for a 
laboratory chief to meet the first step of certification, the chief should 
attend WRD sediment laboratory operation training.  This includes an initial 
1-week training period under a certified sediment lab chief, and attendance at 
periodic meetings of sediment laboratory chiefs.  Upon successful completion 
of this training, these employees become certified sediment laboratory 
chiefs and are authorized to provide certification training in their home 
laboratory to others.


Each participating sediment laboratory normally will be evaluated on-site at 
3-year intervals. For WRD laboratories, the on-site evaluation will take place 
in conjunction with the technical review of surface-water programs for the 
local office.  Other laboratories normally will be evaluated in concert with 
the surface-water technical review of the WRD office that provides the bulk of 
water samples sent to the subject laboratory. The OSW may chose to vary the 
frequency of the evaluations depending on past and ongoing laboratory 
performance or laboratory-analysis workload based on requests by WRD offices 
or thrust programs.

Sediment laboratory reviewers certified by the OSW will lead the on-site 
evaluations of the WRD and contract sediment laboratories.  A standardized 
approach that evaluates and documents laboratory performance in a 
consistent, readily comparable manner will be employed.   

The outcome of the on-site evaluation is included as a section of the 
appropriate District surface-water review report.  Travel-related costs for 
the certified sediment laboratory reviewer are borne by the laboratory being 


This project was developed in 1996 as described in OSW Technical Memorandum 
No. 96.11, "Initiation of a Sediment Laboratory Quality Assurance Project 
(SLQA)" and will continue as part of the national quality assurance 
program.  It is designed to measure the bias and variance of suspended-
sediment data produced by participating sediment laboratories.  The BQS 
currently distributes about 18 standard reference sediment samples annually in 
two separate batches to participating laboratories. The samples are identified 
as quality assurance samples but their sediment-concentration and/or particle-
size distribution values are known only to the BQS. Analytical results and 
methods are returned to the BQS for compilation and statistical analyses. 

Participating laboratories in turn receive a compilation of results specific 
to their laboratory upon completion of the analysis.  Statistics from 
analytical results from all participating laboratories are combined and 
reported to the OSW.

The results from these tests are used as one tool to assess the performance of 
individual sediment laboratories using the aggregate data summary and other 
information as references.  They are also used to populate a national sediment 
laboratory quality assurance data base.  Reference samples provided free-of-
charge by the Division are analyzed and reported without compensation to the 
participating laboratories.


This new project will provide the capability for those submitting 
environmental water-sediment samples to participating laboratories to also 
submit quality-control samples disguised as environmental samples. Like the 
single-blind reference sediment sample project, the double-blind project 
will be designed to measure the bias and variance of suspended-sediment data 
produced by participating sediment laboratories.  Because the samples are 
processed and shipped from the field, the double blind program will document 
shipping procedures to provide information on bias and/or variance 
attributable to routine shipping, processing, and handling steps.  It is hoped 
that within 18 months data will be sufficient to issue a policy memorandum 
that will identify acceptable and unacceptable shipping procedures. 

The results from these tests are used as another tool to assess the 
performance of individual sediment laboratories.  They are also used to 
populate the national data base.   

The quality-control samples will be provided by the BQS to projects and thrust 
programs on a reimbursable basis.  Analytical costs and any costs associated 
with sample preparation and shipping are also borne by those submitting the 
samples.  The quality-control samples will be provided free-of-charge to 
laboratories for internal quality-assurance testing.  Other details of this 
project are under review and will be transmitted later this fiscal year.


Analytical results from all sediment quality-control samples, including 
blanks, are compiled and statistically summarized by the BQS both on a 
laboratory-by-laboratory basis and on a national basis.  The national data set 
will be used to develop relative criteria with which to evaluate the 
performance of each participating sediment laboratory.  These criteria will be 
updated as the data base grows.

The compilation and associated statistical analysis for individual 
laboratories will be provided to the originating laboratory.  The national 
data set will be published with individual labs identified by code.  
Criteria for evaluating the laboratories will also be published.  Data users 
from a given sediment laboratory will be provided the code of the laboratory 
they use to assess its performance with respect to all participating 


Follow-up evaluations may be required for laboratories providing data that 
plot outside statistically determined data-quality boundaries, and/or for 
which substantial deficiencies are detected during on-site reviews.  This 
may entail processing additional quality-control samples; an additional on-
site evaluation; or both.  Its focus may range from general laboratory 
equipment and/or methods, to a single analytical procedure.  The intent of 
follow-up evaluations is to eliminate the source of the identified problems 
and to increase the competence of the laboratory and improve the data it 

The decision for follow-up evaluations will be made by the OSW in concert with 
the BQS and the appropriate District Chief.  The laboratory under review, 
the BQS, and the OSW will share and discuss results of follow-up evaluations 
before the data are added to the national data base.  Recommendations and 
any subsequent quality-assurance testing will be based on the outcome of the 
follow-up evaluation. 

A laboratory that consistently fails to provide adequate results for one or 
more analytical procedures within a year of the follow-up evaluation may be 
barred from providing data from the procedure(s) in question until adequate 
proficiency is demonstrated to the OSW.  Such decisions will be made on a 
case-by-case basis.  Costs associated with follow-up evaluations will be borne 
by the subject laboratory.


This national sediment laboratory quality-assurance program requires 
participating laboratories to maintain up-to-date quality-assurance plans 
which include documentation of its quality-control procedures.  Quality-
control information, such as charts, analysis of laboratory quality-control 
samples, calibration records, and analyst bench logs should be compiled and 
available for review for at least the previous 3 years.  Laboratory quality-
control data are to be fully documented, readily available, and technically 
defensible.  All data from the single- and double-blind quality-assurance 
projects must be made available for storage on a national sediment 
laboratory quality assurance data base.  Procedures for capturing these 
quality-control data will be described this fiscal year.

                                      Thomas H. Yorke
                                      Chief, Office of Surface Water

This memorandum complements OSW Technical Memoranda Nos. 91.11 and 96.11.

WRD Distribution:  A, B, FO, PO