United States
                Environmental Protection
Environmental Monitoring Systems
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

                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
                  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

  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.

  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.

     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,

   e gases—radon,  ammonia,  hydrogen

     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,
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

  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
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