PROGRAMS AND PLANS--Nutrient Sample Size Reduction

In Reply Refer To:                          March 27, 1992
Mail Stop 412


Subject:  PROGRAMS AND PLANS--Nutrient Sample Size Reduction

On April 10, 1992, the National Water Quality Laboratory 
(NWQL) will begin replacing 250 mL brown nutrient bottles and 
1 mL mercuric chloride ampoules with 125 mL brown nutrient 
bottles and 0.5 mL mercuric chloride ampoules.  The purpose 
of this change is to reduce the amount of mercuric chloride 
that is being used in the field and that, subsequently, must 
be disposed of by the NWQL.  Efforts continue towards 
replacing mercuric chloride with another preservation method 
during Fiscal Year 1993.

By this memorandum, we request Districts to place orders (by 
edoc to DENSUPPLY) for replacement bottles and ampoules as 
soon as possible.  Order a supply that will cover your needs 
for the next six months only.  Districts initially will be 
billed for the orders, but will be reimbursed for the costs 
of both bottles and ampoules when the obsolete 1 mL mercuric 
chloride ampoules are returned to NWQL for disposal.  The 
250 mL bottles are not to be returned to NWQL (only the 1 mL 
ampoules).  Districts can dispose of the 250 mL nutrient 
bottles as they see fit.

NWQL expects the exchange of supplies to take about one 
month, and beyond that, an additional month will be allowed 
for receipt of any outstanding 250 mL nutrient samples for 
analysis.  After that time, the 250 mL bottles will no longer 
be accepted by the Login Section.  The exact sample 
acceptance cutoff date will be set by the NWQL after the 
exchange of supplies is completed and will be announced in 
the QWTALK Continuum.

Further details and instructions will be distributed by NWQL 
in the coming weeks.

                                 David A. Rickert

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

Key Words:  Nutrients, preservative, mercuric chloride

Distribution:  A, B, S, FO, PO