Field
Sampling Manual for Reactive Sulphide Tailings
Mine Environment Neutral Drainage at CANMET-MMSL |
MEND
Report 4.1.1
November 1989
Summary
A fundamental
requirement for the monitoring and study of natural environments
is the ability to collect high-quality samples of solid, liquid,
and gaseous phases. It is through the collection of such samples
that analyses can be performed to define existing undisturbed conditions
or to delineate impacts of human activity. The collection of high-quality
samples is the first step in the overall process of environmental
protection and, if an acceptable sample cannot be obtained, then
the subsequent tasks of analysis, interpretation, and response may
be of little benefit. In recognition of this importance, the Mine
Environment Neutral Drainage (MEND) Program has commissioned Canect
Environmental Control Technologies Ltd., a subsidiary of Norecol
Environmental Consultants Ltd., to prepare this manual of sampling
methodology.
A major environmental
concern today is the disturbance of natural environments by human
activities which result in the development of acidic conditions.
This disturbance occurs during industrial activity where air emissions
result in acidic rainfall and during mining and excavation where
reactive sulfide minerals are exposed to the atmosphere. It is an
objective of the MEND Program to examine the evolution of acidic
conditions during mining activity. Acidic conditions at a mine sites
can develop in rock piles, on mine walls, and in tailings impoundments
which hold the waste products from ore processing. This manual specifically
addresses sampling methods for tailings impoundments and their surrounding
basins.
A multidisciplinary
environmental study in the vicinity of a tailings impoundment involves
the collection of solid, liquid, and pore-gas samples. These samples
may be used for physical, chemical, and microbiological analysis
and must be of high quality with minimal disturbance. The optimum
methods for collection of high-quality samples are dependent on
such factors as site-specific conditions and equipment availability,
which preclude the development of a rigid prescriptive guide for
sampling methodology. The collection of high-quality samples may
not even be feasible at some impoundments, requiring a compromise
on quality. As a result, this manual is designed to offer guidance
and recommendations on the selection of appropriate sampling methodology
while recognizing the importance of site-specific conditions and
the value of on-site decision making. Emphasis is placed on maximizing
sample quality by minimizing both sample disturbance and artificial
contamination during sampling. Because subsurface environments are
often chemically reducing (anoxic), a significant source of sample
disturbance and contamination is exposure to the atmosphere.
This manual
contains several indexes in Chapter 2 to summarize the solid, liquid
and pore gas phase methods according to such factors as the type
of required equipment and the degree of isolation from the atmosphere.
A flowchart is also presented in Chapter 2 to summarize the indexes
and to guide the selection of potentially appropriate methodology.
The methods
for collection of samples in this manual are divided into three
primary chapters covering solid, liquid, and pore-gas phases. The
concise presentation of each method explains the objectives, descriptions,
advantages and disadvantages. Chapter 3 presents the methods for
collecting solid-phase samples, divided into the general categories
of (1) heavy-powered equipment including drill rigs, (2) light-powered
equipment including samplers used in association with drill rigs,
and (3) hand-operated equipment. Many of these methods for solid-phase
sampling provide the necessary borehole or excavation needed for
subsequent collection of subsurface groundwater and pore gas using
piezometers, wells, and gas pons. Chapter 4 describes the methods
for collecting liquid-phase samples, divided into categories on
the basis of (1) collecting a sample during drilling, (2) physically
separating water from a solid-phase sample, (3) sampling from a
well installed after drilling (4) sampling from installations established
independently of drilling and (5) retrieving a groundwater sample
using a pump or bailer. In Chapter 5, methods for sampling pore
gas are grouped on the basis of (1) collecting a sample during drilling,
(2) establishing sampling ports after drilling, (3) installing sampling
ports independently of drilling, and (4) employing a syringe sampler
or on-site autoanalyzer.
Chapter 6 contains
a summary of quality control recommendations for the collection
of high - quality solid, liquid and pore-phase samples. The chapter
is based on the individual recommendations in Chapters 3, 4 and
5.
Français
| Contact Us
| Help | Search
| Canada Site
Home | What's
New | CANMET-MMSL
| MMS Site
| NRCan Site
|