WATER QUALITY--Determination of Mercury in Water


                                            May 19, 1970

Quality of Water Branch Technical Memorandum No. 70.12

To:      Regional Hydrologist and District Chiefs, WRD

From:    Chief, Quality of Water Branch, WRD

Subject: WATER QUALITY--Determination of Mercury in Water

We have had several recent inquiries concerning the 
occurrence of mercury in the nation's water resources. The 
enclosed article (Chemical and Engineering, May 11, 1970) 
discusses the observed situation for the Detroit River, 
Michigan. Data on the general occurrence of mercury in U.S. 
waters, however, are sparse. Although mercury is reported 
routinely using spectrographic techniques, sensitivity is 
poor, and other analytical procedures have not been 
available. To our knowledge, no firm standards have been 
established for mercury in water, although present 
discussions have suggested that no measured mercury will be 
tolerated in waters for drinking.

The Methods Development Unit, Denver, Colorado, recently 
adapted a method using a silver wire cell and atomic 
absorption spectrophotometry. The lower detection limit is 
0.1 ug/liter. Additionally, L.L. Thatcher, Radioisotopes 
Unit, WRD, Denver, is developing procedures for "finger 
printing" waters by neutron activation analysis using the 
TRIGA Reactor in Building 15 at the Denver Federal Center. 
Both the Methods Development Unit and the Radioisotopes Unit 
are interested in getting a few samples from suspected areas 
of mercury occurrence .

Accordingly, please consider collecting a water sample or two 
for mercury analysis from one or two streams in your 
District. Sample collection and shipping instructions are 
attached. Results from the analyses will be collated in this 
office with copies distributed to all District offices.

Your cooperation and interest is appreciated, as early 
research on occurrence of mercury in water resources will be 
helpful in national assessment of the situation.



                                  W. H,, Durum

Enclosures

WRD Distribution:
A, B, S, FO




Sample (1). For mercury analysis by atomic absorption the 
sample should be filtered (.45 micron) at time of collection 
and acidified with .7 - .8 ml concentrated nitric acid (for 
500 ml sample ). Polyethyene or glass containers are 
acceptable.

Sample (2). For mercury analysis by neutron activation 
analysis the sample should be a depth integrated sample (if 
possible) unfiltered, with no treatment. Mr. Thatcher will 
determine whether to irradiate the whole water sample (water 
plus sediment) or to irradiate the water and sediment 
separately.

Ship both samples to:

Methods Development Unit
Water Resources Division
Bldg. 25, Denver Federal Center
Denver, Colorado 80225