United States
Environmental Protection
Agency
Environmental Monitoring Systems
Laboratory
Las Vegas NV 89114
Research and Development
EPA-600/S4-84-049 June 1984
EPA Project Summary
Compendium of Selected
Methods for Sampling and
Analysis at Geothermal
Facilities
Cecil H. Kindle, Karl H. Pool, J. Donald Ludwick, and David E. Robertson
The establishment of 'generally ac-
cepted methods for characterizing geo-
thermal emissions has been hampered
by the independent natures of both
geothermal industrial development and
sampling/analysis procedures, despite
three workshops on the latter (Las Vegas
1975. 1977, 1980). An independent
study of the field has resulted in a
compilation of the best methods for
sampling, preservation, and analysis of
potential pollutants from geothermally
fueled electric power plants. These
methods have been selected as the most
usable over the range of application
commonly experienced in the various
geothermal plant sample locations. In
addition to plant and well piping, tech-
niques for sampling cooling towers,
ambient gases, solids, surface, and
subsurface waters are described. Em-
phasis is placed on the use of sampling
'probes to extract samples from hetero-
geneous flows. Where possible, analyt-
ical methods capable of reaching aquatic
life criteria sensitivities are described.
This series of techniques is best, if
applied or directly monitored by one
person to optimize consistent use and
interpretation. Certain sampling points,
constituents and phases of plant opera-
tion are more amenable to quality
assurance improvement in the emission
measurements than others and are so
identified.
This Project Summary was developed
by EPA's Environmental Monitoring
Systems Laboratory, Las Vegas, NV, to
announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Purpose
The purpose of this manual is to provide
direction to persons involved in charac-
terizing flows and locations that may
generate emissions from a geothermal
power plant. The specific goal of this
document is to establish the best methods
forgeothermal situations, andtheirfunc-
tional equivalents, while describing
enough of the problems and variables to
instruct the user about practical problems.
Contents
The techniques detailed in this manual
address the sampling, preservation, and
analysis of inorganic constituents of
geothermal fluids which may be of envi-
ronmental concern. The techniques are
described to permit sampling at all known
emission locations at geothermal plants
as well as at the input to the plant.
Although input to the plant would not
represent an emission point, the sampling
methods included here will permit a
constituent mass balance through the
plant to be calculated. Methods for samp-
ling ground water and ambient air are
described in less detail, since these
techniques are not specific or unique to
geothermal facilities.
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The constituents and parameters of
possible environmental concern that are
addressed in the manual include:
o general—alkalinity, specific conduc-
tance, total dissolved solids, pH
O anions—chloride, fluoride, nitrate, sul-
fate, sulfide
O metals—aluminum, arsenic, barium,
boron, cadmium, chromium, copper,
lead, lithium, manganese, mercury,
molybdenum, selenium, silica, silver,
zinc
e gases—radon, ammonia, hydrogen
sulfide
Where appropriate, possible analytical
methods capable of measuring concentra-
tions down to the aquatic life standards
are described in order to cover the
broadest range of applications.
Sampling techniques and equipment
are described for geothermal wells, piping
for both binary and steam cycle plants,
cooling towers, ponds, streams, sludge
deposits, and fugitive and ambient gases,
as well as locations where two-phase
geothermal flow occurs. The necessity for
using a sample probe inserted into the
main flow is stressed along with the
appropriate use of separators, conden-
sers, and depressurizing valves. Ground-
water sampling is treated separately,
since the techniques are not exclusive to
the geothermal industry. It is recom-
mended that a site-specific evaluation be
conducted before initiating an extensive
program. Current regulations regarding
injection monitoringforgeothermal plants
are briefly referenced.
The preservation guidelines peculiar to
geothermal samples are outlined and
include holding time, containment mate-
rials, chemical treatment, and equipment.
The need to acidify, dilute, and filter
sample fractions in the field is stressed
because of the supersaturated nature of
some constituents.
Analytical methods were selected
based on a combination of analytical
performance, flexibility, ease of operation,
and availability. The stepwise procedures
are described in the text for each element
along with a listing of other usable
methods and an indication of particular
samples for which they are most suited.
As a general rule, for metal analyses, the
laboratory should eliminate interferences
in a particular geothermal brine sample
by using either matrix-matched standards
or through a standard addition calibration.
Recommended analytical methods for
most geothermal samples are identified
by title below.
Titration: alkalinity, chloride, sulfide
Specific Meter, specific conductance
Gravimetry: total dissolved solids
Potemiometry: pH
Selective Ion Exchange: ammonia, fluo-
ride (preceded by distillation)
Color/metric: fluoride (preceded by distil-
lation), silica
Turbidimetric: sulfate
Inductively Coupled Plasma: aluminum,
boron
Atomic Absorption, Gaseous Hydride:
arsenic, selenium
Atomic Absorption, Direct: borium, cop-
per, lithium, manganese, molybdenum
Atomic Absorption, Graphite Furnace:
cadmium, chromium, lead, silver, zinc
Atomic Absorption, Cold Vapor: mercury
Alpha Counter: radon
Chemiluminescence: ammonia (ambient)
Flame Photometry: hydrogen sulfide
(ambient)
The section on quality assurance (QA)
includes a method of arriving at the most
efficient QA balance between field and
laboratory operations for a particular
plant. The sensitivity of various contami-
nants and sample locations to QA im-
provement efforts is estimated for geo-
thermal situations. It is recommended
that the entire monitoring effort, from
sampling to analysis to interpretation, be
under the direction of one person.
C. H. Kindle, K. H. Pool, J. D. Ludwick, andD. E. Robertson are with Battelle, Pacific
Northwest Laboratory, Richland, WA 99352.
Leslie Dunn is the EPA Project Officer (see below).
The complete report, entitled "Compendium of Selected Methods for Sampling
and Analysis at Geothermal Facilities," (Order No. PB 84-199 926; Cost:
$ 17.50, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Monitoring Systems Laboratory
U.S. Environmental Protection Agency
Las Vegas, NV 89 J14
U.S. GOVERNMENT PRINTING OFFICE; 1984 — 759-015/7728
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use S300
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