Environmental Monitoring and Research

Short Hold Time Parameters

Thursday, November 22, 2018 - 10:00 to 10:19 Theatre 3


L. Simpson (Presenting)
Maxxam Analytics

S. Sinclair
Rio Tinto, Diavik Diamond Mines

B. Loescher
Maxxam Analytics

It is well known that it is very difficult to transport samples from remote locations to the laboratory and allow sufficient time to commence analysis within the prescribed short hold times for certain parameters. Also, the majority of published hold times are based on legacy as opposed to hard science.

In an attempt to determine the validity of specific short hold times, a joint study between Diavik and Maxxam was undertaken. The purpose was to determine the stability of short hold time parameters over time using real samples from Diavik sites. Data from two sites will be presented. The first from the Diavik mine water treatment plant influent, which had relatively high levels of the target analytes. The second from a lake water sample with lower native levels of the target analytes. The parameters studied were ammonia (preserved and unpreserved), total nitrogen, nitrite, nitrate, phosphate, total phosphorus and turbidity. All target parameters have a prescribed 3-day hold time.1. pH was also monitored.

Samples were collected by Diavik personnel in one-litre containers and extraordinary logistical measures were taken to get them to Maxxam’s Burnaby laboratory as soon as possible. On receipt, they were immediately subsampled into appropriate containers. Each parameter (except pH and turbidity) was split into three containers: 1) as received; 2) low level spike added and 3) medium level spike added. All samples were analyzed within 3 days of sampling and subsequently analyzed at approximately 3-day intervals thereafter for a period of two weeks.

1 Guidance Manual for Environmental Site Characterization in Support of Environmental and Human Health Risk Assessment – Volume 4 Analytical Methods