Consolidation of Sediment Laboratories

In Reply Refer To:                                   August 25, 1995
Mail Stop 415


Subject:  Consolidation of Sediment Laboratories

The Office of Surface Water (OSW) has noticed a slow but steady loss of 
experienced and trained individuals in the Division's sediment 
laboratories. Available records indicate that about 15 years ago there 
were at least 7 laboratories that routinely analyzed sediment by the 
sieve-pipet method. In 1993, there were only three laboratories that 
routinely reported these data and one of these had about a 5-month 
backlog. The number of requests for particle-size analysis of suspended 
sediment had dropped to less than 800 per year by 1993. 

This situation led OSW to recommend that the Division close any 
laboratory that did not routinely process at least 1,500 concentration 
analyses per year and to limit the number of sediment laboratories 
offering size analysis (other than wet or dry sieve) to those that 
routinely processed at least a specified minimum number of samples. In 
consultation with the Senior Staff, the minimum has been set at 300 size 
analysis samples per year. The OSW further recommended that the 
Sedigraph be phased in as the method of choice for size analysis, that 
laboratories have access to a person with a strong sediment-sampling 
background, and that laboratories develop an accounting structure that 
realistically indicates actual cost of sample analysis. 

The Sedigraph is generally considered to provide more consistent 
results than other types of size analysis. The OSW will provide further 
guidance concerning the phase in of the Sedigraph in a separate 

It is widely recognized that each laboratory should have access to a 
person that has a strong sample-collection background. These field 
consultants have been identified for each laboratory and are listed 
below. Future inspections of the laboratories will evaluate the 
effectiveness of the support provided by these field consultants.

The Senior Staff has agreed that an accounting structure should be 
developed for each laboratory that accurately reflects the actual cost 
of the analyses. The process for the analysis of cost will be determined 
by the remaining laboratories in consultation with their respective 
regions. OSW recommends that the laboratories share information on 
prices and cost, striving to provide a quality analysis at a minimum 

The Regional Hydrologists have agreed to these modified recommendations 
requesting that laboratories, except those listed below, be closed by 
October 1, 1995. These decisions will greatly facilitate the 
maintenance of experienced, trained individuals and acceptable levels 
of quality assurance for the sediment laboratories.

The following laboratories will produce concentrations, sand breaks, 
and dry sieves only:

     Region           Laboratory            Field consultant

     NE               Ohio                  Gregg Koltun
                      Kentucky              Clyde J.Sholar
     SE               Puerto Rico           Carlos Figueroa Alamo
     CR               New Mexico            David Funderburg
                      Montana               Kent Dodge
                      Missouri              Henry Hauck
     WR               California            Larry Trujillo
                      Hawaii                Mike Wong

The following laboratories will offer size analysis using the visual 
accumulation tube, bottom-withdrawal, pipet, or Sedigraph methods:

     Region           Laboratory            Field consultant

     CR               Louisiana             Charlie Demas
                      Iowa                  Von Miller
     WR               Washington            Al Onions

                               Ernest F. Hubbard
                               Acting Chief, Office of Surface Water