Monitoring Trace Metals at
   Ambient Water Quality
        Criteria Levels
            Briefing Book
            January 1995
         William A. Telliard, Chief
          Analytical Methods Staff
       Engineering and Analysis Division
        Office of Science and Technology
            Office of Water

              vvEPA

-------
                    Table of Contents
Section 1-    Monitoring Trace Metals at Ambient Water Quality
             Criteria Levels:  Issues, Plans and Schedule
Section 2-    Method 1669:  Sampling Ambient Water for
             Determination of Trace Metals at EPA Water Quality
             Criteria Levels
Section 3-    Quality Control Supplement for Determination of Trace
             Metals at EPA Water Quality Criteria Levels Using
             EPA Metals Methods
Section 4-    Guidance on the Documentation and Evaluation of
             Trace Metals Data Collected for Clean Water Act
             Compliance Monitoring
Appendices
Appendix A- Laboratories
Appendix B- Office of Water Interim Guidance Concerning the
             Collection of Metals Data at WQC Levels
             (November 8, 1994)
Appendix C- Office of Water Policy and Technical Guidance on
             Interpretation and Implementation of Aquatic Life
             Metals Criteria (October 1, 1993)

-------
                    SECTION 1

 Monitoring Trace Metals at Ambient Water Quality
     Criteria Levels:  Issues, Plans and Schedule

EPA Office of Water, Engineering & Analysis Division

-------
      Monitoring Trace Metals at
Ambient Water Quality Criteria Levels:
      Issues, Plans, and Schedule
              October 1994
    U.S. Environmental Protection Agency
              Office of Water
      Office of Science and Technology
   Engineering and Analysis Division (4303)
              401 M St. SW
          Washington, DC 20460

-------
                                                      Monitoring Trace Metals at Ambient WQC Levels
                                           SUMMARY

The Clean Water Act requires that ambient water quality criteria (WQC) published by EPA reflect the
latest scientific knowledge concerning the physical fate (e.g., concentration and dispersal) of pollutants,
the effects of pollutants on ecological and human health and welfare, and the effect of pollutants on
biological  community diversity, productivity, and stability.  Since the inception of its water quality
standards program in 1965, it has been the Agency's position that, because analytical detection limits are
not related to actual environmental impacts, they should not be a consideration when calculating water
quality criteria.  This position  is consistent with statutory requirements that water quality standards are
to be protective of designated stream uses.  Further, it is believed that setting the criteria at levels that
reflect adequate protection forces the improvement of analytical detection methods.1

Current ambient WQC levels for trace metals require measurement capabilities at levels as much as 280
times lower than those achievable using existing EPA methods and required to support technology-based
permits. This document addresses the difficulties associated with measuring trace metals at ambient WQC
levels and outlines a plan and schedule for achieving such measurements.

The difficulties in measuring metals concentrations at WQC levels include: (1) precluding contamination,
(2) a lack of methods for measurement of some trace metals and biologically significant species of these
metals at WQC levels, and (3) a lack of environmental laboratories capable of performing trace metals
measurements on a large-scale, routine basis. The Analytical Methods Staff of the Office of Science and
Technology's (OST) Engineering and  Analysis Division (EAD) is engaged in a number of activities to
address these challenges.   Specifically, EAD

        •       Has  written a  draft sampling method that describes the sample handling and quality
               control procedures necessary to assure reliable sampling of trace metals.
        •       Has supplemented existing EPA methods with the necessary analytical guidance to assure
               reliable measurements  at WQC levels. The analytical guidance is in the form of a quality
               control (QC) supplement to existing EPA methods.  A first draft of this QC supplement
               has been written by EAD.
        •       Has established a working committee of recognized trace metals analysis experts to assist
               with the development,  review, and improvement of sampling and analysis techniques for
               determination of trace metals.
        •       Is developing additional methods needed to allow reliable measurements of those metals
               that cannot be measured at WQC levels using the supplemented EPA methods.
        •       Is developing data review guidance that will allow reviewers to assess the quality of data
               gathered using the sampling method, analytical methods, and QC  supplement.

EAD plans to validate the sampling method and test the QC supplement and analytical methods in at least
one laboratory capable of making trace-metals measurements.

Routine measurement at WQC levels can be achieved within a short  time for those metals and metal
species for which an EPA analytical method is available.  (Such methods can be supplemented to include
the rigorous sample handling and quality control procedures that are necessary to  deliver verifiable data
at WQC levels.) Development of methods for  the remaining metals and  developing capabilities for
analysis of those metals in commercial laboratories will require considerable effort  and may take more
than a year to achieve. The Water Offices should be aware that not being able to measure certain metals
at WQC levels may  preclude enforcement of WQC levels for these  metals.
        'Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants; Suites' Compliance' (also referred to as
        The National Toxics Rule'), 40 CFR Part 131, (57 FR 60848, December 22, 1992).
 October 1994

-------
                                                       Monitoring Trace Metals at Ambient WQC Levels
                                         BACKGROUND
EPA's increased emphasis on water quality-based permitting has necessitated the determination of metals
and other analytes at levels much lower than those required by technology-based effluent limits and
afforded by routine analyses  in environmental laboratories. The first three columns of Table 1 below
compare ambient WQC levels with minimum levels achieved by methods used hi EPA's technology-based
effluent guidelines program and typically employed to determine permit compliance. Also shown are the
method detection  limits (MDLs)  required to achieve WQC levels and  the lowest MDLs in presently
available EPA methods.

                                             Table 1
  Lowest  EPA Ambient Water Quality Criteria, Required Detection Levels, and Minimum Levels
                and Method Detection Limits Achieved by Existing EPA Methods
Metal


Antimony
Arsenic
Cadmium
Chromium (III)
Chromium(VI)
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Minimum
Level
(ug/L)1
20
10
5
—
20
25
5
0.2
40
5
10
10 .
20
Lowest Ambient
Water Quality
Criterion (ug/L)2
14'
0.018s
0.32s
57s
10.5
2.5
0.146
0.012
7.1
5.0
- 0.31*
1.7'
28*
MDL Needed
to Achieve
WQC (ug/L)3
1.4
0.002
0.032
5.7
1.05
0.25
0.014
0.001
0.71
0.5
0.031
0.017
2.8
Lowest EPA
MDL Currently
Available (ug/L)4
0.4
0.5
0.016
—
0.3
0.023
0.074
0.01
0.081
0.6
0.1
0.3
0.3
        Minimum level for reliable measurement in methods used in EPA's technology-based effluent guidelines program.
        Lowest of the freshwater, marine, and human health WQC promulgated by EPA for 14 states at 40 CFR Part 131 (57
        FR 60848), with hardness-dependent freshwater aquatic life criteria adjusted in accordance with 57 FR 60848 to reflect
        the worst case hardness of 25 mg/L CaCO, and appropriate aquatic life criteria adjusted in accordance with 10/1/93
        Office of Water guidance to reflect dissolved metals criteria.
        Required Method Detection Limit (MDL, 40 CFR Part 136, Appendix B), with safety factor of 10 to allow reb'able
        measurements at WQC level.
        Method Detection Limit (MDL) as listed in existing EPA method.
        Criterion reflects recalculated value using IRIS. See 57 FR 60848 and Water Quality Criteria Summary. USEPA, OST,
        HECD, 5/1/91.
        Hardness dependent criterion.
The determination of many trace metals in environmental samples at WQC levels has been accomplished
in marine science research laboratories. The most serious problem faced by these and other laboratories
that attempt to determine metals at trace  concentrations is the potential for sample contamination from
any metal allowed to contact the sample. A recent discovery by the U.S. Geological Survey (USGS) that
some metals  data in one of its major databases may be the result of sample contamination and similar
findings in EPA's New York/New Jersey Harbor studies suggest the need for EPA to take steps to ensure
October 1994

-------
Monitoring Trace Metals at Ambient WQC Levels
that similar results are not produced as EPA continues to make measurements at WQC levels.24

In general, in order to achieve accurate and precise measurement of a particular concentration, both the
detection limit and  the blank results should be less than one-tenth of that concentration.  The fourth
colunyi in Table  1  above lists the MDLs required for determination of trace metals  at WQC levels.
These values reflect MDLs that are 10 times lower than the WQC level to ensure that trace contamination
will be detected and that the potential reporting of false positives will be  minimized.

The required MDLs shown in the fourth column can be compared  with the lowest MDLs currently
available in EPA  methods, shown in the last column of Table 1.  For arsenic, the level by which the
existing  MDL must be  lowered  to make reliable measurements  at the  WQC level is  a factor  of
approximately 280;  for mercury the factor is approximately 10; and for lead the factor is approximately
5.  Improvements in any measurement system by these factors is not straightforward, and considerable
resources will be required to attain these levels.

Potential for False Positives Resulting From Contamination

Because  trace metals  are  ubiquitous in the environment,  the  precautions  necessary  to preclude
contamination are more extensive than those required to preclude contamination when synthetic organic
compounds and other non-ubiquitous substances are determined.  These difficulties and the recent USGS
findings  strongly  suggest that EPA  should implement measures to avoid the possibility of producing
results that may later be shown to be the result of contamination.

Assessment of U.S. Laboratory Capability

Over the past year, EAD staff have contacted the foremost researchers in the field of trace metals
measurements and have visited the laboratories of several of these researchers.  The main conclusion
drawn from these contacts and visits is that the measurement of trace metals at WQC levels is  a much
more formidable problem than initially believed.  At present, EAD is not aware of a single laboratory
that is capable of reliably determining all  of the metals at the required WQC levels for which ambient
criteria have been published, and there are very few laboratories that are capable of reliably determining
even a subset of the metals at these levels. It is believed that this lack of existing analytical capability
will necessitate laboratory improvements that will,take months to years to accomplish.
        Contamination of Dissolved Trace Element Data:  Present Understanding. Ramifications, and Issues that Require
        Resolution, Office of Water Quality Technical Memorandum 91.10; U.S. Geological Survey, Reston, VA Sept. 30,
        1991.

        Evaluation of Trace-Metal Levels in Ambient Waters and Tributaries to New York/New Jersey Harbor for Waste Load
        Allocation; Environmental Protection Agency, Office of Wetlands, Oceans, and Watersheds and Region II, Jan. 9,
        1992.  (Prepared by Battelle Ocean Sciences, 397 Washington Street,  Duxbury. MA 02332).
                                                                                      October 1994

-------
                                                      Monitoring Trace Metals at Ambient WQC Levels
                              METAL FORMS AND SPECIATION

The bioavailability of a metal in natural waters depends on the chemical form in which it exists.  Metals
can ocfiur in organic and inorganic forms.  The organic form of a given metal can exist as one or more
organo-metallic compounds; the inorganic form can exist in one or  more oxidation states.  Sample
preparation and analysis procedures, and the equipment required for each, can differ considerably for
measurement of the various forms.  Therefore, determination of more than one form of a given metal
may require multiple sample handling procedures, sample preservation techniques, sample preparation
procedures, and analytical methods. These differences are summarized below.

Total, Total Recoverable, and Dissolved  Forms

Determination of "total metals" is directed at all forms of the metal in a sample including dissolved metals
and the metals  in all particulates.  Total metals are determined by vigorous digestion of the sample with
a hot, strong acid or acids to dissolve all forms of the metal.

Determination of "total recoverable metals" is directed at metals weakly bound to particle surfaces plus
dissolved metals.  Total recoverable metals are determined by digestion with hot, dilute mineral  acid(s)
to remove the weakly bound metals without dissolving the particles to which they are bound.

Determination of "dissolved metals" is directed at only those particles, molecules, and  elementary forms
of the metal that are able to pass through a 0.45 micron filter.  Dissolved metals are determined by
filtering the sample and acidifying it to preserve the metals.   Current  Office of Water (OW) guidance
recommends the use of dissolved metals to set  and measure  compliance with water  quality standards
because the dissolved metal more closely approximates the bioavailable fraction of metal in the water than
does the total recoverable form.4  Current OW guidance also provides recommendations concerning
conversion factors that should be used to calculate EPA. dissolved metals criteria from the published total
recoverable metals criteria.  All dissolved metals criteria printed and discussed  in this document are
calculated in accordance with the current OW guidance.

Oxidation  States

Dissolved metals can occur in natural waters in several  oxidation states,,  some of which are more toxic
than others. For example, chromium occurs in the hexavalent (Cr*6) and trivalent (Cr+3) forms, of which
the hexavalent  form is considerably more toxic to aquatic life than the trivalent form.   Similarly, the
inorganic forms of arsenic include arsenate (As*5) and arsenite (As*3).  Implementation of water  quality
criteria for multiple oxidation states of a particular metal may necessitate the use of different  sample
handling procedures, different holding times, and different analytical methods for monitoring purposes.

Organo-metallic Species

The bioaccumulation potential  of methylmercury  in organisms is in the  range of 106 - 108;  therefore,
determinations of methylmercury may be of greater concern than determinations of mercury.  Similarly,
organo-arsenicals may be of greater environmental concern than the inorganic forms. Further, within
a group of organo-metallics, each individual compound may have different toxic effects.  If water quality
criteria are developed for organo-metallic  species, it will be  necessary utilize sample preparation and
        Prothro, M., Acting Assistant Administrator for Water, Memorandum to Water Management Division Directors and
        Environmental Services Division Directors, Oct. 1, 1993.
 October 1994

-------
Monitoring Trace Metals at Ambient WQC Levels
analytical procedures that differ from those used in determination of the inorganic forms (although the
organo-metallics can usually be measured as a group or individually with the same procedure).
                                                                                     October 1994

-------
                                                     Monitoring Trace Metals at Ambient WQC Levels
        IMPLEMENTATION OF TRACE METALS ANALYSES IN EPA PROGRAMS

USGS Plans

The USGS has embarked on a program to lower the levels at which trace measurements will be made.
This  program  will occur  in  two phases.   USGS' Phase I effort is directed  at  making  reliable
measurements at the one part-per-billion (ppb; ug/L) level.  To achieve this level, USGS believes that
significant improvement must occur in sample collection.  USGS has specified sampling equipment, has
developed a sampling manual, and has had its program operational at the one ppb level since November
1993.  USGS does not have the need to regulate discharges, and all analyses conducted by USGS will
be at  its Water Quality Laboratory near Denver.  Therefore, USGS does not have the need to develop
detailed, written methods and monitor multiple facilities that are making trace metals measurements. In
contrast, EPA will need to develop  detailed methods, sampling guidance,  and data review criteria to
support Federal and State regulatory programs.

In order to make reliable measurements at the one ppb level, USGS has attained detection limits on the
order of 0.1 ppb.  Based on information provided by USGS, HAD .estimates that achieving the one ppb
level in commercial and state laboratories will cost approximately $5,000 in fixed costs for individual
laboratory modifications.   Per sample,costs are expected  to  increase  by  $50 - 100  because  of the
additional bottle preparation and care in sampling required.

In Phase II, USGS will move to reliable measurements at the 0.1 ppb level.  Achieving this level will
require detection limits on the order  of 0.01 ppb and is estimated to take one year since it will require
extensive modification of field sampling and laboratory equipment and protocols.  USGS has begun work
on a self-designed Class-100 clean room and will equip this room with Class-100 clean benches. The
Class-100 facility will be used for sample and sample bottle preparation. To  preclude contamination and
fix responsibility for metals analysis  at the 0.1 ppb level, USGS is considering teams of personnel who
will carry out all aspects of the metals determinations, from bottle cleaning through sampling through
sample preparation through the analysis. Although this system is  inefficient because a small group of
highly trained people must perform even the most menial tasks, the system vests responsibility in people
who know most about the potential pitfalls associated with trace metals determinations.

Based on  information provided by USGS and other laboratories, HAD estimates that achieving the 0.1
ppb Phase II level  will  require the typical commercial  or state laboratory to invest approximately
$325,000  in fixed costs for laboratory modifications and equipment, primarily for a clean room,  clean
benches, inductively coupled plasma mass spectrometer (ICP/MS) with hydride attachment, mercury
analyzer,  and stabilized temperature platform graphite furnace atomic absorption  spectrophotometer
(STGFAA).

Bevond USGS Levels

The above section describes USGS'  Phase I and Phase II plans for measurement of trace metals at the
1 and 0.1  ppb level.  As noted in that section, achievement of the Phase II 0.1 ppb level is estimated by
USGS to  take  more than  one year, and is estimated by  HAD  to require more than $325,000 in
implementation costs for state and commercial laboratories. However, achievement of the Phase II levels
by USGS  will be inadequate for EPA purposes because EPA and State ambient water quality criteria for
some metals  are more than ten times lower than the USGS Phase II levels.   Therefore, EPA efforts to
achieve WQC levels must  necessarily be more extensive than USGS'  efforts.  Further,  because the
potential for contamination  at these lower levels is great, the Agency must be certain that data collected
at these levels are reliable.
October 1994

-------
Monitoring Trace Metals at Ambient WQC Levels
Based on information provided by USGS and other laboratories, BAD estimates that achieving WQC
levels may cost upwards of $500,000 in fixed costs for setup and operation of a single laboratory,
including all equipment.  These costs are driven by the same equipment costs as in the USGS Phase II
costs, but are increased by analyzers for various species of mercury and  other metals, and by the
additional cleanliness requirements for measurement of these elements at high part-per-quadrillion levels.
Per sample costs may increase by $100 - 200, but can be expected to drop as laboratories become skilled
at handling samples.


Projected EPA Activities

Guidance concerning the implementation of aquatic life metals criteria was issued on 10/1/93.3  As part
of the Office of Science and Technology's efforts to achieve the measurement of trace metals at these and
other ambient WQC levels, three guidance development efforts are currently being directed by William
A. Telliard of the Engineering and Analysis Division. These efforts are focused on the development of
sampling, analytical,  and data review guidance.   To expedite these efforts, HAD has established a
working committee of  recognized  trace metals  analysis  experts  to assist with  development and
improvement of sampling and analysis techniques.  The first meeting of this committee was held on
November 12, 1993.  BAD has retained certain members of this committee to review and validate the
sampling guidance and the analytical guidance/methods.  Specific activities related to .the development
of these guidance materials are described below.

Sampling Guidance

For sampling guidance,  BAD originally intended to avoid duplication of effort by using portions of the
USGS manual that are applicable to EPA programs.  However, after  reviewing the  USGS sampling
manual,  it was determined that the manual is  so specific to  USGS' programs that  a separate EPA
sampling manual is needed. To meet this need, BAD completed a draft Method for Sampling Ambient
Water for Determination of Metals at EPA Ambient Water Quality Criteria Levels in January 1994.
Following limited peer review, the draft was revised in October .1994, and is currently undergoing more
extensive peer review within the Agency. Final revision of this sampling guidance, which includes clean
techniques recommended by USGS and others, is planned for December 1994.  In addition, BAD  is
planning  to issue a similar guidance document  that has  been adapted to  reflect  effluent sampling
requirements.  The draft guidance for effluent sampling  is scheduled for completion in January 1995.
Validation of these procedures is planned for early 1995.

Analytical Methods

EPA's Environmental Monitoring Systems Laboratory in Cincinnati, Ohio (EMSL-Ci) has developed
methods for the determination of several toxic (priority pollutant) metals at ambient WQC levels. These
methods and their  corresponding detection levels are shown below  in Table 2 along with the lowest
applicable WQC.  Because these  methods lack the rigorous sample handling and quality control
procedures that are necessary to deliver verifiable data at the WQC levels, BAD  has  written a QC
supplement to these methods.  This draft Quality Control Supplement for Determination of Metals  at
Ambient Water Quality Criteria Levels  Vsing EPA Metals Methods supplements EPA methods 200.7,
200.8, 200.9, 200.10, 200.13, and 218.6, and provides the procedures  necessary to  reliably measure
antimony, cadmium, hexavalent chromium, copper, nickel, and zinc at the water quality criteria level.
    5    Prolhro, M., Acting Assistant Administrator for Water, Memorandum to Water Management Division Directors and
        Environmental Services Division Directors; Oct. 1, 1993.
 8                                                                                 October 1994

-------
                                                       Table 2
 Lowest EPA Water Quality Criteria for Toxic Metals and Species; Existing EPA Methods that Achieve or
    Come Closest to Achieving these Criteria; and Analytical Techniques, Minimum Levels, and Method
                                     Detection Limits for these EPA Methods
r
Metal
Antimony
Arsenic
fjiHtriimn
Chromium (HI)
Chromium (VI)
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Lowest
Ambient
Water Quality
Criterion
(ug/L)'
14
0.018
0.32
57
10.5
2.5
0.14
0.012
7.1
5
0.31
1.7
28


EPA method, analytical technique, and MDL/ML
in ug/L
Method
number
200.8
200.9
200.9
200.13
—
218.6
200.10
200.10
245.7
200.8
200.9
200.10
200.9
200.8 ,
200.8
200.7
200.8
200.9
Analytical
technique
ICP/MS
STGFAA
STGFAA
CC/STGFAA
—
Ion Chrom. .
CC/ICP/MS
CC/ICP/MS
CVAF
ICP/MS
STGFAA
CC/ICP/MS
STGFAA
ICP/MS
ICP/MS
ICP/AES
ICP/MS
STGFAA
MDL2
0.4
0.8
0.5
0.016

0.3
0.023
0.074
0.01
0.5
0.6
0.081
0.6
0.1
0.3
2
1.8
0.3
MLJ
1
2
2
0.05

1
0.05
0.2
0.02
2
2
0.2
2
0.2
1
5
5
1
WQC
level
achieved4
Yes
Yes
No
Yes
No
Yes
Yes
No
No
Yes
Yes
Yes
No
No
No
Yes
Yes
Yes
Key:
Notes:
1.
2.
3.
4.
ICP      =  Inductively coupled plasma                      Ion chrom
AES     =  Atomic emission spectrometry                    CC
MS      =  Mass spectrometry                    .         CVAF
CFAA   =  Graphite furnace atomic absorption spectrometry     STGFAA
Ion chromatography
dictation/concentration
Cold vapor atomic fluorescence
Stabilized temperature GFAA
Lowest of the freshwater, marine, and human health WQC promulgated by EPA for 14 states at 40 CFR Part 131 (57 FR 60848),
with hardness-dependent freshwater aquatic life criteria adjusted in accordance with 57 FR 60848 to reflect the worst case hardness
of 25 mg/L CaCO, and all aquatic life criteria adjusted in accordance with the 10/1 /93 Office of Water guidance to reflect dissolved
metals criteria.  A complete listing of all WQC, including total, dissolved, and levels calculated with a hardness of 25 mg/L CaCO,
and a hardness of 100 mg/L CaCO, is provided in Appendix A.
Method Detection Limit (40 CFR Part  136, Appendix B) as listed in existing EPA method.
Minimum Level (ML) calculated by multiplying the existing EPA MDL by 3.18 and rounding result to the nearest multiple of 1, 2,
5, 10, 20, 50,  etc in accordance with procedures utilized by EAD and described in the EPA Draft National  Guidance for the
Permitting, Monitoring, and Enforcement of Water Quality-Based Effluent Limitations Set Below Analytical Detection/QuantitoMon
Levels, March 22, 1994.
Determination of the metal is achieved if MDL is less than one-tenth the WQC level.
October 1994

-------
Monitoring Trace Metals at Ambient WQC Levels
EAD believes that the supplemented methods may also yield reliable measurements of lead, selenium,
silver, and thallium at water quality criteria levels.  Single laboratory testing of this QC Supplement is
underway; revision of the QC Supplement to  reflect the results of the single laboratory validation is
scheduled for completion in December 1994. New EPA methods that consolidate the validated techniques
described in the existing methods and the QC Supplement are scheduled for release in March 1995.

Additional method development efforts are required for the measurement of arsenic, trivalent chromium,
and mercury at WQC levels.  EMSL-Ci has recently developed a method for determination of mercury,
but this method does not achieve the detection level needed to make reliable measurements.at the WQC
level.  A draft EAD method for  determination of mercury at WQC levels has recently been completed
and is undergoing internal review.  EAD has also identified and is evaluating techniques for the analysis
of arsenic and trivalent chromium at water quality criteria levels.  EAD intends to utilize the results of
the current studies to prepare draft methods for these analytes.

The QC Supplement and any method(s) developed by EAD will undergo single laboratory testing in
marine research laboratories presently making  trace metals determinations.  These laboratories will be
used because the routine laboratories employed  by EPA do not have the facilities and familiarity with the
ultra-clean techniques necessary to  make these  determinations reliably.

Finally, EAD has  gathered information regarding EPA methods and other analytical techniques that may
be useful in measuring metal  forms and species for which no WQC exist, but which were identified by
EAD's trace metals  committee to be of regulatory concern at the  local level.  These forms and species,
which are shown in  Table 3, are: total chromium, free copper, methylmercury, molybdenum, total tin,
and organotin.6             .
                                             TableS
          Existing EPA Methods and Techniques Providing the Lowest Minimum Levels
                        and Method Detection Limits for Additional Metals
                  Identified to be of Potential Concern by the EAD Workgroup
Metal
Chromium
Copper (free)
Mercury (methyl)
Molybdenum
Tin
Tin (organo)
EPA method, analytical technique, and
MDL/MLinug/L
Method
number
200.8
200.9
—
—
200.8
200.9
—
Analytical
technique
ICP/MS
STGFAA
—
—
ICP/MS
STGFAA
—
MDL
0.9
0.1


0.3
1.7

ML
2
0.2


1
5

Key:
ICP/MS
STGFAA
=   Inductively Coupled Plasma/Mass spectrometry
=   Stabilized temperature graphite furnace atomic absorption spectrometry
        Beryllium and arsenic (III) were also discussed by the BAD trace metals workgroup because water quality criteria for
        these metals were previously published by EPA, but subsequently withdrawn.  The techniques identified by the
        members of the EAD trace metals workgroup as most closely achieving the previously published WQC levels are
        shown in Appendix B of this document for informational purposes.
 10
                                                                             October 1994

-------
                                                      Monitoring Trace Metals at Ambient WQC Levels
 If water quality criteria are developed for these metals forms and species, EAD is prepared to supplement
 existing methods and develop new methods as needed to make reliable measurements at the WQC levels.

 Appendix B provides a complete summary of the method development efforts required for each metal of
 interest.  For each metal .form and species, Appendix B details the lowest ambient WQC, analytical
 techniques and available EPA methods that are or may be capable of allowing measurements at that level,
 and the estimated detection limit for that technique.  (In some cases, it is generally thought that new
 generation instruments and techniques such as multiple injections may reduce method detection limits for
 the EPA methods cited in Tables 2 and 3  to levels lower than the currently specified value.  In such
 cases, the  lower method detection limit is  cited in Appendix B and is suffixed with "est.".) Because
 analysis of briny samples may be required of permittees discharging into harbor areas,  Appendix B also
 provides information regarding additional sample preparation procedures that may be required to analyze
 brackish samples.

 Data Review

 Some reported trace metals concentrations in existing EPA databases may be the result of contamination.
 EAD has  been asked to  develop  data review protocols  for  examination  of these  data  to  make  a
 determination that the data are,  or are not,  of sufficient  quality  for EPA purposes.   It is EAD's
 understanding that these data  are not accompanied by  quality control (QC) data,  particularly data for
 blanks that would prove that the positive results are not the result of contamination. In the absence of
 data for blanks and other QC analyses, little can be done to determine if these data are reliable, and the
 writing of data review protocols  and extensive review of the data  will not  improve data  quality.  In
 addition, it is EAD's understanding that the analytical methods used for  data gathering  may not have
 included quality control criteria that would result in verifiable data. It is EAD's experience that analytical
methods and data review  are linked in  that data collected using methods that include rigorous quality
 control criteria can be validated, whereas data collected using methods that lack these criteria cannot.

 During FY95, EAD will develop functional guidelines for review of metals data generated in  accordance
 with the analytical methods developed by EMSL-Ci and EAD.  These guidelines will allow the quality
 of the data to be defined prior to its entry into EPA databases and will provide a trail from the data back
 to its source.

 Schedule

 The schedule in Table 4 below details EAD's projected efforts to develop guidance for determination of
 metals at WQC levels.
 October 1994                                    ,                                              11
                                                                                                   1    /?

-------
Monitoring Trace Metals at Ambient WQC Levels
                                            Table 4
                                        Schedule of Plans
• . Sampling
Activity
Hold Committee Meeting
Write Draft Sampling Method
Release Sampling Method for Peer Review
Release Sampling Method for Agency Review
Revise Sampling Method Based on Agency Review
Release Revised Sampling Method for Further Review
Release Final Sampling Method
Release Draft Effluent Sampling Guidance for Review
Analytics
Activity
Hold Committee Meeting
Write QC Supplement to EPA Methods
Release QC Supplement for Peer Review
Release QC Supplement for Agency Review
Issue Draft QC Supplement
Test QC Supplement
Release Final QC Supplement
Release Consolidated Methods
Data Review
Activity
Write Data Package Requirements for QC Supplement
Write Draft of Data Review Guidance
Revise Guidance Based on Tests
Issue Final Guidance
Guidance
Scheduled Completion Date
12 Nov. 1993
21 Jan. 1994
26 Jan. 1994
18 April 1994
12 Oct. 1994
20 Oct. 1994
31 Dec. 1994
31 Jan. 1995
1 Method
Scheduled Completion Date
12 Nov. 1993
01 Jan. 1994
26 Jan. 1994
18 April 1994
01 June 1994
15 Nov. 1994
31 Dec. 1994
31 Mar. 1995
/ Guidelines ' ,
Scheduled Completion Date
30 Sept. 1994
31 Mar. 1995
30 June 1995
30 Aug. 1995
An estimated $50,000 will be needed to perform single laboratory testing of EAD's sampling method and
QC supplement in marine research laboratories already equipped with the instrumentation and facilities
necessary to achieve the required detection levels.  Additional costs will be incurred if subsequent testing
efforts are performed in commercial environmental laboratories typically contracted by EPA.
12
October 1994

-------
                                      Appendix A
   EPA Ambient Water Quality Criteria for Total Recoverable and Total Dissolved Priority
Pollutant Metals and Metal Species Calculated at a Hardness of 100 mg/L and 25 mg/L CaCO3

-------
                                 EPA Ambient Water Quality Criteria for Total Recoverable and Total Dissolved Priority Pollutant Metab and  Metal Species
                                                                        Calculated at a Hardness of 100 mg/L and 25 mg/L CaCO,

McUl
Sb
As
Cd">
Cr (IIDm
Cr(VD
Cum
Pbm
Hi
Nim
Se
Agm
Tl
Zn">
Ambient Water Quality Criteria11' 
0.31
—
31
Chronic0'
Tot. Rec.
lOOrag/L
c»co,
—
190
I.I
210
11
12
3.2
0.012
160
5
—
—
110
Chronic141
Tot. .Diss.
100 mg/L
CXX>,
—
181
0.94
179
10.5
10.2
0.8
	 
136
	 »>
—
...
94
Chronic0*
Tot. Rec.
25 mg/L
CaCO,
._
190
0.38
67
11
3.6
0.54
0.011
49
5
—
...
33
Chronic'4'-0'
Tot. Disi.
25 mg/L
c«co,
—
181
0.32
57
10.5
3.1
0.14
	 m
42
	 m
-
_.
28
Marine Criteria
Acute01
Tot. Rec.
~
69
43
...
1100
2.9
220
2.1
75
300
2.3
...
95
Acute(4>
Tot. Diss.
—
65.6
36.6
—
1050
2.5
110
1.8
64
	 a>
2.0
—
81
Chronic"'
Tot. Rec.
—
36
9.3
—
50
2.9
8.5
0.025
8.3
71
—
—
86
Chronic14'
Tot. Disi.
—
34.2
7.9
_.
47.5
2.5
2.1
	 m
7.1
	 (S)
—
—
73
Human Hethh Criteria
H,0/organism0>
Tot. Rec.
. M">
0.0W>
—
—
—
—
~
0.14
610*
— '
_
/.7">
—
organism*4
Tot. Rec.
4300"
0.14«
_
—
—
—
—
0.15
4600">
— .
—
6.3">
—
EPA
Method
200.8
200.9
200.13
—
218.6
200.10
200.10
245.7
200.10
200.9
200.8
200.8
200.9
Lowest
MDL
(«/U
0.4
0.5
0.016
— .
0.3
0.023
0.074
0.01
0.081
0.6
0.1
0.3
0.3
MDL
Needed
WL)"
1.4
0.0018
0.032
5.7
l.OS
0.25
0.014
0.0012
0.71
0.5
0.031
0.17
2.8
WQC
Mctr*
Yet
No
Yet
No
Yea
Yea
No
•MMHMlilH
No
Yea
No
No
No
Yea
(1)         WQC promulgated in the National Toxict Rule (NTR) for 14 states at 40 CFK Part 131 (57 FR 60848).  Critria for metals, listed at 40 CFK Part 131 arc expressed a> total recoverable at a hardness of 100 mg/L CaCO, and a water
           effect ratio (WER) of 1.0. The lowest WQC for each analytc is shaded.

(2)         The MDL needed to achieve determination at the WQC levels is one-tenth of the lowest WQC. The WQC level is considered met if the MDL is less than or equal to one-tenth of the lowest WQC.

(3)         As listed in the NTR at 40 CFK Part 131 for total recoverable metals.  Hardness dependent freshwater acute and chronic criteria expressed at a hardness of 100 mg/L CaCO, and a WER of 1.0.

(4)         For Cd, Cr Gil). Cu. Ni. and Zn, acute and chronic criteria for dissolved metals and metal species were calculated by taking 85% of the corresponding uxal recoverable criteria level.  For Aa and Cr (VO. acute and chronic crteria
           for dissolved metals and metal species were calculated by taking 95 % of the corresponding total recoverable criteria level.  For lead, acute dissolved criteria were calculated by taking 50% of the corresponding lota] recoverable fcwl;
           for lead chronic criteria, dissolved criteria were calculated by taking 25% of the total recoverable levels.  Dissolved values for mercury chronic criteria and selenium acute and chronic criteria were not calculated because these metals
           bkMCCumulate, and dissolved criteria would not be appropriate. (Guidance Document on Dissolved Criteria: Expression of Aquatic Life Criteria, October 1993. Attachment 2 to memorandum from Martha Prothro to Water Management
           Division Directors, October 1, 1993.)

(5)         Hardness dependent freshwater acute and chronic criteria recalculated at a hardness of 25 mg/L CaCO, and a WER of 1.0 as specified at 40 CFR Part 131.36 (b)(2).  For dissolved metals, hardness calculations  were performed prior
        .   to adjusting for dissolved levels.»

(6)         Criterion reflects recalculated value using IRIS.

(7)         Freshwater criteria are hardness dependent for this metal.

(8)         Metal is bic«ccumuUtivc and, therefore,  it is not appropriate lo calculate WQC for dissolved levels.  (Guidance Document on Dissolved Criteria: Expression of Aquatic Life Criteria. October  1993. Attachment 2 to memorandum
           from Martha Prothro lo Water Management  Division Directors, October I, 1993.)

-------
                  Appendix B
Analytical Methods for Trace Metals Determinations
                                                                         2 r

-------
                                            Appendix B
              Analytical Methods and Technologies for Trace Metals Determinations
ANTIMONY (Sb)

Lowest WQC Level Required:  14 ug/L

Species:  Total only

Analytical Techniques Capable of Achieving WQC Level:
Technique
ICP/MS
HYDAA
STGFAA
Detection      EPA
limit (ug/L)    method   Note
0.04 est.       200.8
0.1 est.        none
0.8            200.9
Extraction/Concentration Techniques Required for Seawater:  None if hydride generation is used

ARSENIC (As)

Lowest WQC Level Required:  0.018 ug/L (for Total Arsenic)

Species: Total

Analytical  Techniques Capable of Achieving WQC Level:  None

Techniques Capable of Achieving Lowest Detection Levels:

Total arsenic:

Technique	
Detection      EPA
limit (ug/L)    method   Note
HYD/ICP/MS
HYDAA
0.003 est.      none     1 L sample req'd
0.1 est.        none
Arsenic (III)*:
Technique	
pH~4/Cryo distill/HYDAA
Detection
limit (ug/L)
0.001 est.
EPA
method
none
Note
Extraction/Concentration Techniques Required for Seawater:  None if hydride generation is used

*EPA has replaced aquatic life criteria for arsenic(III) with aquatic life criteria for total arsenic.  Potential techniques for
analysis of arsenic (III) are presented above because they were discussed by the HAD trace metals workgroup with the thought
that analysis of total arsenic and of arsenic (III) may be useful in determining the need to measure organoarsehic (which is
naturally produced by phytoplankton) in certain local environments. In addition, EPA's decision to base WQC for arsenic on
the total recoverable form was based in part on the lack of practical analytical methods to measure trivalent As (see response to
comments published in 57 FR 60848,  12/22/92).

-------
                                         Appendix B
             Analytical Methods and Technologies for Trace Metals Determinations
                                         (continued)
BERYLLIUM (Be)

WQC Level Required:  None*

Species:  Total

Techniques Capable of Achieving Lowest Detection Levels:

                             Detection      EPA
Technique	          limit fug/L)    method   Note
ICP/MS     ,                 0.05 est.       200.8
Mult. inj./STGFAA           0.01 est.       200.9
Complex. /extr/fluor/
  GC/Sel. detector            0.002          none
Extraction/Concentration Techniques Required for Seawater:
Complex./extr./fluor/GC/Sel. detector

"EPA has withdrawn the water quality criteria for beryllium. The information provided above was discussed by the EAO trace
metals workgroup because of its earlier concern to EPA.
CADMIUM (Cd)

Lowest WQC Level Required:  0.32 ug/L

Species:  Total

Analytical Techniques Capable of Achieving WQC Level:

                             Detection      EPA
Technique	         limit (ug/L)    method   Note
CC/STGFAA                 0.016         200.13

Extraction/Concentration Techniques Required for Seawater:
Complex with APDC or DDDC/extr./then as above
EPA methods  200.12 and 200.13

-------
                                         Appendix B
             Analytical Methods and Technologies for Trace Metals Determinations
                                         (continued)
 CHROMIUM (Cr)

 Lowest WQC Level Required:  Chromium (VI): 10.5 ug/L
                             Chromium (III):  57 ug/L

 Species:  Total Chromium, Chromium (VI), and Chromium (III)
Analytical Techniques Capable of Achieving WQC Level:

Chromium (VI):
                            Detection     EPA
Technique	         limit (ug/L)   method  Note
Ion chrom/Deriv/Color.       0.3           218.6    No metal parts!
APDC/MIBK/STGFAA       0.1           none     May be unreliable
Techniques Capable of Achieving Lowest Detection Levels

Chromium (III):
                            Detection     EPA
Technique	  .       limit (ug/L)   method   Note
None Identified
Total chromium*:
                            Detection     EPA
Technique           ,        limit (ug/L)    method   Note	
ICP/MS                     O.lest.       200.8
STGFAA                    0.1           200.9

Extraction/Concentration Techniques Required for Seawater:  None in addition to above

                                          /
"EPA water quality criteria do not exist for total chromium. Potential techniques for analysis of total chromium are presented
above because they were discussed by the HAD trace metals workgroup.
                                                                                                19

-------
                                         Appendix B
             Analytical Methods and Technologies for Trace Metals Determinations
                                         (continued)
COPPER (Cu)
      *
Lowest WQC Level Required: 2.5 ug/L (for Total Copper)

Species: Total and "Free" (thought to be Cu2*)

Analytical Techniques Capable of Achieving WQC Level:

Total copper:
                             Detection      EPA
Technique	         limit (ug/L)    method  Note
JCP/MS                     0.1 est.       200.8
Mult. inj. STGFAA           0.1 est.       200.9
CC/ICP/MS                  0.023         200.10
Techniques Capable of Achieving Lowest Detection Levels:

Free copper*:
                             Detection
Technique	         limit (ug/L)    method   Note
Ligand/titr./STGFAA         0.1 est.       none      One sample per day
Extraction/Concentration Techniques Required for Seawater:
Total: APDC/DDDC chelation/MIBK extraction/STGFAA
Free:  None in addition to above

*EPA water quality criteria do not exist for free copper.  Potential techniques for analysis of free copper are presented above
because they were discussed by the EAD trace metals workgroup with the knowledge that investigation of site-specific criteria
for free copper is. underway in some localities.
 LEAD (Pb)

 Lowest WQC Level Required:  0.14 ug/L

 Species: Total

 Analytical Techniques Capable of Achieving WQC Level: None

 Techniques Capable of Achieving Lowest Detecton Levels:
                              Detection      EPA
 Technique	          limit fug/L)    method   Note
 ICP/MS                      0.1 est.        200.8
 Mult. inj.  STGFAA           0.2 est         200.9
 CC/ICP/MS                  0.074          200.10
 Extraction/Concentration Techniques Required for Seawater:  Complex with APDC or
 DDDC/extr./then as above EPA methods 200.12 and 200.13

-------
                                          Appendix B
              Analytical Methods and Technologies for Trace Metals Determinations
                                           (continued)
MERCURY (Hg)

Lowest WQC Level Required:  0.012 ug/L (Total Mercury)

Species: Total and Methyl

Analytical Techniques Capable of Achieving WQC Level: None

Techniques Capable of Achieving Lowest Detection Levels:

Total mercury:              ^
                             Detection      EPA
Technique	         limit (ug/L)    method   Note
Reduce/P&T/At.Fl.           0.001 est.     none
CVAF                       0.01           245.7
Methyl mercury*:
                             Detection      EPA
Technique	         limit (ug/L)    method   Note	
Distill./ethylation/
P&T/GC/pyrolysis/At.
Fl.                          0.0001        none      Nick Bloom

Extraction/Concentration Techniques Required for Seawater: None in addition to above

"EPA water quality criteria do not exist for methylmercury. Potential techniques for analysis of mcthylmcrcury are presented
above because they were discussed by the EAD trace metals workgroup due to its well-known bioaccumulation potential and
significance in the environment.

MOLYBDENUM (Mo)

WQC Level Required: None"

Species:  Total

Analytical Techniques Capable of Achieving Lowest Detection Level:

                             Detection      EPA
Technique                   limit (ug/L)    method   Note	
ICP/MS                      0.05 est.       200.8
Mult. inj. STGFAA          0.1  est.       200.9

Extraction/Concentration Techniques Required for Seawater: None; ICP/MS detection limit = 0.5
ug/L                                             .

"EPA water quality criteria do not exist for molybdenum.  Potential techniques for analysis of molybdenum are presented above
because they were discussed by the EAD trace metals workgroup.

-------
                                       Appendix B
             Analytical Methods and Technologies for Trace Metals Determinations
                                       (continued)
NICKEL (Ni)

Lowest WQC Level Required: 7.1 ug/L

Species: Total

Analytical Techniques Capable of Achieving Water Quality Criteria Level:

                            Detection     EPA
Technique	         limit (ug/L)   method   Note	
ICP/MS                     0.5          200.8
STGFAA                    0.6          200.9
CC/ICP/MS                 0.081         200.10
Extraction/Concentration Techniques Required for Seawater:
SELENIUM (Se)

Lowest WQC Level Required: 5.0 ug/L

Species:  Total

Analytical Techniques Capable of Achieving WQC Level: None

Techniques Capable of Achieving Lowest Detection Levels:

                            Detection     EPA
Technique	         limit (ug/L)   method   Note	
HYD/ICP/MS               0.05 est.      none
HYD/STGFAA              0.02         none
Mult. inj. STGFAA          0.5 est.       200.9    Fresh water only

Extraction/Concentration Techniques Required for Seawater:  None if hydride generation is used

-------
                                        Appendix B
             Analytical Methods and Technologies for Trace Metals Determinations
                                        (continued)
SILVER (Ag)

Lowest WQC Level Required: 0.31 ug/L

Species:  Total

Analytical Techniques Capable of Achieving WQC Level:  None

Techniques Capable of Achieving Lowest Detection Levels:

                            Detection      EPA
Technique	         limit (ug/L)    method  Note
ICP/MS                     0.02 est.       200.8
APDC/STGFAA             0.02          none    pH sensitive

Extraction/Concentration Techniques Required for Seawater: None with APDC chelation/extraction
THALLIUM (Tl)

Lowest WQC Level Required:  1.7 ug/L

Species:  Total

Analytical Techniques Capable of Achieving WQC Level:  None

Techniques Capable of Achieving Lowest Detection Levels:

                            Detection     EPA
Technique	         limit (ug/L)   method Note	
ICP/MS                     0.05  est.      200.8
STGFAA                   0.5 est.       200.9

Extraction/Concentration Techniques Required for Seawater: None required with ICP/MS at
projected WQC levels

-------
                                         Appendix B
             Analytical Methods and Technologies for Trace Metals Determinations
                                         (continued)
TIN(Sn)

WQC Level Required:
       Total: None*
       Organo:  None*

Species:  Total and Organo

Analytical Techniques Capable of Lowest Detection Levels:

Total tin:
                             Detection     EPA
Technique	         limit (ug/L)    method   Note
ICP/MS                      0.1 est.        none
STGFAA                    1.7           200.9
Organo-tin:
                             Detection      EPA
Technique	         limit (ug/L)    method   Note
Tropolone/ext./GC/FPD   :    0.05 est.      none     Also atomic
                                                    emiss. detector

Extraction/Concentration Techniques Required for Seawater:  Unknown if required for .total tin
because WQC is not known; none in addition to above for organo-tin

*EPA water quality criteria do not exist for tin and organo-tin. Potential techniques for analysis of tin and organo-tin are
presented above because they were discussed by the HAD trace metals workgroup.
ZINC (Zn)          '     '

Lowest WQC Level" Required:  86 ug/L

Species: Total

Analytical Techniques Capable of Achieving WQC Level:

                              Detection     EPA
Technique	          limit (ug/L)   method  Note
ICP                          2             200.7
ICP/MS                      1.8           200.8
STGFAA                     0.3           200.9
 Extraction/Concentration Techniques Required for Seawater: APDC/DDDC/MIBK extraction/FLAA;
 contamination serious problem

-------
                   SECTION 2

     Method 1669:  Sampling Ambient Water for
          Determination of Trace Metals at
         EPA Water Quality Criteria Levels

EPA Office of Water, Engineering & Analysis Division

-------
                     Method 1669

Sampling Ambient Water for Determination of Trace Metals
           at EPA Water Quality Criteria Levels
                    December 1994
          U.S. Environmental Protection Agency
                    Office of Water
            Office of Science and Technology
        Engineering and Analysis Division (4303)
                    401 M St. SW
                Washington, DC 20460
                                                              .7?

-------
 Method 1669
 Acknowledgements

 This sampling method was prepared under the direction of William A. Telliard of the Engineering
 and Analysis Division (HAD) within the U.S. Environmental Agency's (EPA's) Office of Science and
 Technology (OST).  This-sampling method was prepared under EPA Contract 68-C3-0337 by
 DynCorp Environmental, with the assistance of Interface, Inc.

 The following researchers in marine chemistry contributed to the philosophy behind this sampling
 method.  Their contribution is gratefully acknowledged:

 Shier Berman, National Research Council, Ottawa, Ontario, Canada;
 Nicholas Bloom, Frontier Geosciences Inc, Seattle, Washington;
 Eric Crecelius, Battelle Marine  Sciences Laboratory, Sequim, Washington;
 Russell Flegal, University of California/Santa Cruz, California;
 Gary  Gill, Texas A & M University at Galveston, Texas;
 Carlton Hunt and Dion Lewis, Battelle Ocean Sciences, Duxbury, Massachusetts;
 Carl Watras, Wisconsin Department of Natural Resources, Boulder Junction, Wisconsin

 Additional support was provided by Ted Martin of the EPA Office of Research and Development's
 Environmental Monitoring Systems Laboratory in Cincinnati, Ohio.

 This version of the method was prepared after .observations  of sampling teams from the University of
 California at Santa Cruz, the Wisconsin Department of Natural Resources, the U.S.  Geological
 Survey, and Battelle Ocean Sciences. The assistance of personnel demonstrating sampling techniques
 used by these institutions is gratefully acknowledged.

Disclaimer

This sampling method has been  reviewed and approved for publication by the Analytical Methods
 Staff within the Engineering and Analysis Division of the U.S.  Environmental Protection Agency.
 Mention of trade names or commercial products does not constitute endorsement  or recommendation
 for use.

 Further Information

 For further information, contact:

       William A.  Telliard
       Engineering and Analysis Division (4303)
       U. S. Environmental Protection Agency
       401  M St. SW
       Washington  DC 20460
       Phone: 202-260-7134
       Fax:   202-260-7185

-------
                                                                                    Method 1669
 1.0     SCOPE AND APPLICATION

 1.1     This method (Method 1669) is for the collection and filtration of ambient water samples for
        subsequent determination of trace metals.  It is designed to support the implementation of
        water quality monitoring and permitting programs administered under the Clean Water Act.

 1.2     Method 1669 is applicable to the metals listed in Table  1 and other metals, metals species,
        and elements amenable to determination at trace levels.

 1.3     Method 1669 is accompanied by the Quality Control Supplement for Determination of Trace
        Metals  at EPA  Water Quality Criteria Levels Using EPA Metals Methods (the QC
        Supplement). The QC Supplement is necessary to assure that trace metals will be determined
        reliably when EPA analytical methods are used. Method 1669 contains the QC necessary to
        assure that sampling will be performed reliably.

 1.4     Method 1669 is not intended for determination of metals at. concentrations normally found in
        treated  and untreated discharges from industrial facilities.  Existing regulations (40 CFR Parts
        400 - 500) typically limit concentrations in industrial discharges to the mid to high part-per-
        billion (ppb)  range, whereas ambient metals concentrations are normally in the low part-per-
        trillion  (ppt)  to low ppb range.

 1.5     The ease of contaminating ambient water samples with the metal(s) of interest and interfering
        substances cannot be overemphasized.  This method includes sampling techniques that should
        maximize the ability of the sampling team to collect samples reliably and eliminate sample
        contamination., These techniques are given in Section 8.0 and are based on findings of
        researchers performing trace metals analyses (References 14.1 - 14.9).

 1.6     Clean and ultra-clean—The terms  "clean" and "ultra-clean" have been used in other Agency
        guidance to describe the techniques needed to reduce or  eliminate contamination in trace
        metals determinations.  These terms  are not used in this  sampling method due to a lack of
        exact definitions. However, the information provided in this method is consistent with
        summary guidance oh clean and ultra-clean techniques (Reference 14.10).

 1.7     This sampling method follows the EPA Environmental Methods Management Council's
        "Format for Method Documentation" (Reference 14.11), and is therefore consistent with the
        QC Supplement and the EPA methods that  are referenced in the QC Supplement (Referenced
        Methods).  Where appropriate, sections of this sampling method expand upon sections for
        sampling in the Referenced  Methods to include the increased operational procedures and QC
        necessary for collection of samples for trace metals at ambient WQC levels.  In these
        instances, the procedures and QC  in this sampling method take precedence over the
        procedures and QC in the Referenced Methods; otherwise, all procedures and QC in the
        Referenced Methods must be followed.

 1.8     Method 1669 is  "performance-based";  i.e., an alternate sampling procedure or technique may
        be used, as long as the performance  requirements in the Referenced Methods and the QC
        Supplement are met.  Section 9.2  gives details of the tests and documentation required to
        support equivalent performance.
December 1994

-------
Method 1669
1.9     For dissolved metal determinations, samples must be filtered through a 0.45 jim capsule filter
        at the field site.  The filtering procedures are described in this method. The filtered samples
        may be preserved in the field or transported to the laboratory for preservation. Procedures
     ,   for field preservation are detailed in this sampling method; procedures for laboratory
        preservation are provided in.the QC Supplement.

1.10    The procedures in this method are. for use only by personnel thoroughly trained in the
        collection of samples for determination of metals at ambient WQC levels.
2.0     SUMMARY OF METHOD

2.1     Prior to sample collection, all sampling equipment and sample containers are cleaned in a
        laboratory or cleaning facility using detergent, mineral acids, and reagent water.  The
        laboratory or cleaning facility is responsible for generating an acceptable equipment blank to
        demonstrate that the sampling equipment and containers are free from trace metals
        contamination prior to shipping them to the field sampling team (Section 9.3).

2.2     After cleaning,  sample containers are filled with weak acid solution, individually double
        bagged, and shipped to the sampling site.  All sampling equipment is also bagged for storage
        or shipment.

2.3     The laboratory or cleaning facility must prepare a large carboy or other appropriate clean
        container filled  with reagent water for use  with collection of field blanks during sampling
        activities.  The  reagent-water-filled container should be shipped to the field site and handled
        as all other sample containers and sampling equipment.  At least one field blank should be
        processed per site, or one per every ten samples, whichever is more frequent (Section 9.4).
        If samples are to be collected for determination of trivalent chromium,  additional QC aliquots
        are processed by the sampling team  as described in Section 9.6.

2.4     Upon arrival at  the sampling site, one member of the two person sampling  team is designated
        as "dirty hands"; the second member is designated as "clean hands". AH operations  involving
  ,-     contact with the sample bottle and transfer of the sample from the sample collection device to
        the sample bottle are handled by the individual designated as "clean hands".  "Dirty hands" is
        responsible for preparation of the sampler (except the sample container itself), operation of
        any machinery,  and for all other activities  that do not involve direct contact with the sample.
/        • -
2.5     All sampling equipment and sample  containers used for metals determinations at ambient
        water quality criteria levels must be non-metallic and free from any material that may contain
        metals.

2.6     Sampling personnel are required to wear clean, non-talc gloves at all times when handling
        sampling equipment and sample containers.

2.7     In addition to processing field blanks at each site, a field duplicate must be collected at each
        sampling site, or one field duplicate per every ten samples,  whichever is more frequent
        (Section 9.5).
                                                                                   December 1994

-------
                                                                                    Method 1669
2.8     Sampling
        2.8. 1   Whenever possible, samples are collected facing upstream and upwind to minimize
               introduction of contamination.

        2.8.2   Samples may be collected while working from a boat or while on land.

        2.8.3   Surface samples  are collected using a grab sampling technique.  The principle of the
               grab techniques is to fill a sample bottle by rapid immersion in water and capping to
               minimize exposure to airborne paniculate matter.

        2.8.4   Subsurface samples are collected by suction of the sample into an immersed sample
               bottle or by pumping the sample to the surface.
2.9     Samples for dissolved metals are filtered through a 0.45 nm capsule filter at the field site.
        After filtering, the samples are double bagged and iced immediately.  Sample containers are
        shipped to the, analytical laboratory.  The sampling equipment is shipped to the laboratory or
        cleaning facility for re-cleaning.

2.10    Acid preservation of samples is performed in the field or in the laboratory.  Field preservation
        is necessary for determinations of trivalent chromium.  It has also been shown that field
        preservation can increase sample holding times for hexavalent chromium to 30 .days; therefore
        it is recommended that preservation of samples for hexavalent chromium be performed in the
        field.  For other metals, however, the sampling team may prefer to utilize laboratory
        preservation of samples in order to expedite field operations and to minimize the potential for
        sample contamination.

2.11    Sampling activities are documented through paper or computerized sample tracking systems.


3.0 DEFINITIONS

3.1     Apparatus— Throughout this sampling method, the sample containers, sampling devices, and
        all other materials and devices that will contact the sample will be referred to collectively as
        the Apparatus.

3.2     Other definitions of terms are given in the Glossary (Section 15) at the end of this method.
4.0    CONTAMINATION AND INTERFERENCES

4.1    Contamination problems in trace metals analysis

       4.1.1   Preventing ambient water samples from becoming contaminated during the sampling
               and analytical process is the greatest challenge faced in trace metals determinations.
               Over the last two decades, marine chemists have come to recognize that much of the
               historical data regarding the concentrations of dissolved trace metals in seawater are
               erroneously high because the concentrations reflect contamination from sampling and
               analysis rather than ambient levels.   More recently, historical^trace metals data
December 1994

-------
Method 1669
               collected from freshwater rivers and streams have been shown to be similarly biased
              v due to contamination during sampling and analysis (Reference 14.12). Therefore, it is
               imperative that extreme care be taken to avoid contamination when collecting and
               analyzing ambient water samples for trace metals.

       4.1.2   There are numerous routes by which samples may become contaminated. Potential
               sources  of trace metals contamination during sampling include:  metallic or metal-
               containing sampling equipment, containers, labware (e.g. talc gloves that contain high
               levels of zinc), reagents, and deionized water; improperly cleaned and stored
               equipment, labware, and reagents; and atmospheric  inputs such as dirt and dust from
               automobile exhaust, cigarette smoke, nearby roads,  bridges,  wires, poles, etc.  Even
               human contact can be a source of trace metals contamination.  For example, it has
               been demonstrated that dental work (e.g., mercury amalgam fillings) in the mouths of
               laboratory personnel can contaminate samples that are directly exposed to exhalation
               (Reference 14.3).

4.2    Contamination Control

       4.2.1   Philosophy—The philosophy behind contamination control is to ensure that any object
               or substance that contacts the sample is non-metallic and free from any material that
               may contain metals.

               4.2.1.1        The integrity of the results produced cannot be compromised by
                             contamination of samples. Requirements and suggestions for control
                             of sample contamination are given in this sampling method, the QC
                             Supplement, and the Referenced Methods.

               4.2.1.2        Substances in a sample or in the surrounding environment cannot be
                             allowed to contaminate the Apparatus used to collect samples for  trace
                             metals measurements. Requirements and suggestions  for protecting
                             the Apparatus are given in this sampling method and the QC
                             Supplement.

               4.2.1.3        While contamination control is essential, personnel health and safety
                             remain the highest priority.  Requirements and suggestions for
                             personnel safety are given in Section 5 of this sampling method, the
                             QC Supplement, and the Referenced Methods.

       4.2.2   Avoiding contamination—The best way to control contamination is to completely
               avoid exposure of the sample and Apparatus to contamination in the first place.
               Avoiding exposure means performing operations in  an area known to be free from
               contamination.  Two of the most important factors in avoiding/reducing sample
               contamination are: (1) an awareness of potential sources of contamination and (2) -
               strict attention to work being performed.  Therefore, it is imperative that the
               procedures described in this method be carried out by well-trained, experienced
               personnel. Documentation of training should be kept on  file and readily available for
               review.
                                                                                  December 1994

-------
                                                                                     Method 1669
               4.2.2.1        Minimize exposure—The Apparatus that will contact samples or
                              blanks should only be opened or exposed in a clean room, clean
                              bench, glove box, or clean plastic bag, so that exposure to
                      •   .     atmospheric inputs is minimized.  When not being used, the Apparatus
                              should be covered with clean plastic wrap,  stored in the clean bench
                              or in a plastic box or glove box, or bagged in clean,  colorless zip-type
                              bags.  Minimizing the time between cleaning and use will also reduce
                              contamination.

               4.2.2.2        Wear gloves—Sampling personnel must wear clean, non-talc gloves
                              (Section 6.7) during all operations involving handling of the
                              Apparatus, samples, and blanks.  Only clean gloves may touch the
                              Apparatus.  If another object or substance is touched, the glove(s)
                              must be  changed before again handling the  Apparatus.  If it is even
                              suspected that gloves have become contaminated,  work must be
                              halted, the contaminated gloves removed, and a new pair of clean
                              gloves put on.  Wearing multiple layers of  clean gloves will allow the
                              old pair  to be quickly stripped with minimal disruption to the work
                              activity.   .

               4.2.2.3         Use metal-free  Apparatus—All Apparatus used for metals
                              determinations  at ambient water quality criteria levels must be non-
                              metallic  and free of material that may contain metals.

                              4.2.2.3.1      Construction materials—Only the following materials
                                            should come in contact with samples:. fluoropolymer
                                            (FEP, PTFE), conventional or linear polyethylene,
                                            polycarbonate, polysulfone, polypropylene, or ultra-
                                            pure quartz.  PTFE is less desirable than FEP because
                                            the sintered material in PTFE may contain
                                            contaminants  and is susceptible to serious memory
                                            effects (Reference 14.6).  Only fluoropolymer should
                                            be used  for samples that will be analyzed for mercury
                                            because mercury, vapors can diffuse in or out of other
                                            materials, resulting either in contamination or low-
                                            biased results (Reference  14.3).  Glass and metal must
                                            not be used under any circumstance.  Regardless of
                                            construction, all materials that will directly or
                                            indirectly contact the sample must be  cleaned  using the
                                            procedures described in the QC Supplement and must
                                            be known to be clean and metal-free before
                                            proceeding.

                              4.2.2.3.2      The following materials have been found to contain
                                            trace metals and must not be used to hold liquids that
                                            come in contact  with the  sample or must not contact
                                            the  sample, unless these materials have been shown to
                                            be free of the metals of interest at the desired level:
                                            Pyrex, Kimax, methacrylate, polyvinylchloride, nylon,
December 1994                                                                                 5
                                                                                                    S3

-------
             Method 1669
                                                          and Vycor (Reference 14.6).  In addition, highly
                                                          colored plastics, paper cap liners, pigments used to
                                                          mark increments on plastics, and rubber all contain
                                                          trace levels of metals and must be avoided (Reference •
                                                          14.13).

                                           4.2.2.3.3 .   .   Serialization—Serial numbers should be indelibly
                                                          marked or etched on each piece of Apparatus so that
                                                          contamination can be traced, and logbooks should be
                                                          maintained to track the sample from the container
                                                          through the sampling process to shipment  to the
                                                          laboratory.  Chain-of-custody procedures may also be
                                                          used if warranted so that contamination can be traced
                                                          to particular handling procedures or lab personnel.

                                           4.2.2.3.4       The Apparatus should be clean when received by the
                                                          sampling team.  If there are any indications that the
                                                          Apparatus is not clean (e.g., ripped storage bags), an
                                                          assessment of the likelihood of contamination must be
                                                          made. Sampling must not proceed if it is possible that
                                                          the Apparatus is contaminated.  If the Apparatus is
                                                          contaminated, it must be returned to the laboratory or
                                                          cleaning facility for proper cleaning before any
                                                          sampling activity resumes.

                                           4.2.2.3.5       Details for recleaning the Apparatus between collection
                                                          of individual samples are provided in Section 10.

                            4.2.2.4         Avoid sources of contamination—Avoid contamination by  being aware
                                           of potential  sources  and routes of contamination.

                                           4.2.2.4.1       Contamination by carry-over—Contamination may
                                                          occur when a sample containing low concentrations of
                                                          metals is processed immediately after a sample
                                                          containing relatively high concentrations of these
                                                          metals. At sites where more than one sample will be
                                                          collected, the sample known or expected to contain the
                                                          lowest concentration of metals should be collected first
                                                          with the sample  containing the highest levels collected
                                                          last  (Section 8.1.4).  This will help minimize  carry-
                                                          over of metals from high concentration samples to low
                                                          concentration samples. When necessary, the sample
                                                          collection system may be rinsed with dilute acid and
                                                          reagent water between samples followed by collection
                                                          of a field blank (Section 10.3).

                                           4.2.2.4.2       Contamination by samples— Significant contamination
                                                          of the Apparatus may result when untreated effluents,
                                                          in-process waters,  landfill leachates, and other samples
             6                                                                                 December 1994


•if

-------
                                                                                     Method 1669
                                             containing mid- to high-level concentrations of
                                             inorganic substances are processed.  As stated in
                                             Section 1, this sampling method is not intended for
                                             application to these samples, and samples containing
                                             high concentrations of metals (> ~ 10 /ig/L) must not
                                             be collected, processed, or shipped at the same time as
                                             samples being collected for trace metals
                                             determinations.

                              4.2.2.4.3       Contamination by indirect contact— Apparatus that
                                             may not directly contact samples may still be a source
                                             of contamination.  For example, clean, tubing placed in
                                             a dirty plastic bag may  pick up contamination from the
                                             bag and subsequently transfer the contamination to the
                                             sample.  Therefore,  it is imperative that every piece of
                                             the Apparatus that is directly or indirectly used in the
                                             collection of ambient water samples be cleaned as
                                             specified in the QC Supplement.

                              4.2.2.4.4       Contamination by airborne paniculate matter—Less
                                             obvious substances capable of contaminating samples
                                             include airborne particles.  Samples may be
                                             contaminated by airborne dust,  dirt, paniculate matter,
                                             or vapors from: automobile exhaust; cigarette smoke;
                                             nearby corroded or rusted bridges, pipes,  poles, or
                                             wires; nearby roads; and even human breath (Section
                                             4.1.2). Whenever possible, the sampling  activity
                                             should occur as far as possible from sources of
                                             airborne contamination (Section 8.1.3).  Areas where
                                             nearby soil is bare and subject to wind erosion should
                                             be avoided.

4.3     Analytical interferences—Interferences resulting from samples will vary considerably from
        source to source, depending on the diversity of the site being sampled.   If a sample is
        suspected of containing substances that may interfere in the determination of trace metals,
        sufficient sample should be collected to allow  the laboratory to  identify and overcome
        interference problems.

5.0     SAFETY

5.1     The toxicity or carcinogenicity of the chemicals used in this method has not been  precisely
        determined; however, these chemicals should be treated as a potential health hazard.
        Exposure should be reduced to the  lowest possible level.  Sampling teams are responsible for
        maintaining a current awareness file of OSHA regulations regarding the safe handling of the
        chemicals  specified in this method.  A reference file of Material Safety Data Sheets should
        also be made available to all personnel  involved in sampling.
December 1994

-------
Method 1669
5.2     Operating in and around water bodies carries the inherent risk of drowning.  Life jackets must
        be worn when operating from a boat, when .sampling in more than a few feet of water, or
        when sampling in swift currents.

5.3     Collecting samples in cold weather, especially around cold water bodies, carries the risk of
        hypothermia, and collecting samples in extremely hot and humid weather carries the risk of
        dehydration and heat stroke. Sampling team members should wear adequate clothing for
        protection in cold weather and should carry an adequate supply of water or other liquids for
        protection against dehydration in hot weather.

6.0     APPARATUS AND  MATERIALS

        NOTE:         Brand names, suppliers, and part numbers are for illustration purposes
        only and no endorsement is implied.  Equivalent performance may be achieved using
        apparatus and materials other than those specified here.  Meeting the performance
        requirements of this method is the responsibility of the sampling  team and laboratory.

6.1     All sampling equipment  and sample containers must be pre-cleaned in a laboratory or cleaning
        facility, as described  in the QC Supplement, prior to shipment to the field site.  To minimize
        difficulties in sampling,  the equipment should be packaged and arranged to minimize field
        preparation.

6.2     Materials such as gloves (Section 6.7), storage bags (Section 6.8), and plastic wrap (Section
        6.9), may be used new without additional cleaning unless the results of the equipment blank
        pinpoint any of these materials as a source of contamination. In this case, either a different
        supplier must be obtained or the materials must be cleaned.

6.3     Sample bottles—Fluoropolymer (FEP, PTFE), conventional or  linear polyethylene,
        polycarbonate, or polypropylene; 500-mL or 1-L with lids.  Cleaned sample bottles should be
        filled with 0.1% HC1 (v/v) until use.  Note: If mercury is a target analyte,  fluoropolymer
        bottles must be used.  Refer to the QC Supplement for bottle cleaning procedures.

6.4     Surface sampling devices—Surface samples are collected using  a grab sampling technique.
        Samples may be collected manually by direct submersion of the bottle into the water or by
        using a grab sampling device. Examples of grab samplers are shown in Figures 1 and 2  and
        may be used at sites where depth profiling is neither practical nor necessary.  Whenever
        possible, grab sampling devices should be cleaned and prepared for field use  in a class 100
        clean room. Preparation of the devices in the field should be done within the glove bag
        (Section 6.6).  Regardless of design, sampling devices must be constructed of non-metallic
        material (Section 4.2.2.3.1) and free from material that contains metals.  Commercially
        available samplers may be used provided that any metallic or metal-containing parts are
        replaced with parts constructed of appropriate material.

        6.4.1   The grab sampler in Figure 1 consists of a heavy fluoropolymer collar fastened to the
               end of a 2-meter long polyethylene pole, which serves  to remove the sampling
               personnel  from the immediate vicinity of the sampling point.  The collar holds the
               sample bottle. A fluoropolymer closing mechanism, threaded onto the bottle, enables
               the sampler to open and close the bottle under water, thereby avoiding surface
               microlayer contamination (Reference 14.14). Polyethylene, polycarbonate, and
8                                                                                 December 1994

-------
                                                                                     Method 1669
               polypropylene are also acceptable construction materials unless mercury is a target
               analyte.  Assembly of the cleaned sampling device is as follows (refer to Figure 1):

               6.4.1.JL        Thread the pull cord (with the closing mechanism attached) through
                              the guides and secure the pull ring with a simple knot.  Screw a
                          I    sample bottle onto the closing device and insert the bottle into the
                              collar. Cock the closing plate so that the plate is pushed away from
                              the operator.

               6.4.1.2        The cleaned and assembled sampling device should be stored in a
                              double layer of large, clean zip-type polyethylene bags or wrapped in
                              two layers of clean polyethylene wrap if it will not be used
                              immediately.

        6.4.2   An alternate grab sampler design is  shown in Figure 2.  This grab sampler is used for
               discrete water samples and is constructed so  that a capped clean bottle can be
               submerged, the cap removed, sample collected, and bottle recapped at a selected
               depth.  This device eliminates sample contact with conventional samplers (e.g., Niskin
               bottles), thereby reducing the risk of extraneous contamination.  Because a fresh bottle
               is used for each sample, carryover from previous samples is eliminated (Reference .
               14.15).

6.5     Subsurface  sampling devices— Subsurface sample collection may be appropriate in lakes and
        sluggish deep river environments or where depth profiling is determined to be necessary.
        Subsurface  samples are collected by pumping the sample into a sample bottle.  Examples of
        subsurface collection systems  include the the jar system device shown in Figure 3 and
        described in Section 6.5.1 or the continuous flow apparatus shown in Figure 4 and described
        in Section 6.5.2.  Whenever possible,  sampling devices should be cleaned and prepared for  •
        field use in a class 100 clean room.  Preparation of the devices in the field should be done
        within the glove bag (Section  6.6).  Regardless of design,  sampling devices must be
        constructed of non-metallic material (Section 4.2.2.3.1) and free from material that contains
        metals.  Fluoropolymer or other material shown not to adsorb or contribute mercury must be
        used if mercury is a target analyte; otherwise, polyethylene, polycarbonate, or polypropylene
        are acceptable.  Commercially available sampling devices  may be used provided that any
        metallic or metal-containing parts are replaced with parts constructed of non-metallic material.

        6.5.1  Jar  sampler (Reference 14.14)— The jar sampler (Figure 3) is comprised of a heavy
              fluoropolymer one-liter jar with a fluoropolymer lid equipped with two 1/4-inch
              fluoropolymer fittings. Sample enters the jar through a short length of fluoropolymer
              tubing inserted into one fitting. Sample is pulled into the jar by pumping on
              fluoropolymer tubing attached to the other fitting.  A thick fluoropolymer plate
              supports the jar and provides attachment points for a fluoropolymer safety line and
               fluoropolymer torpedo counter weight.

              6.5.1.1         Advantages of the jar sampler for depth sampling are: (1) all wetted
                              surfaces are fluoropolymer and can be rigorously cleaned, (2) the
                              sample is collected into a sample jar from which the sample is readily
                              recovered, and the jar can  be easily re-cleaned, (3) the suction device
                              (a peristaltic or rotary vacuum pump, Section 6.15) is located in the
December 1994

-------
Method 1669
                              boat, isolated from the sampling jar, (4) the sampling jar can be
                              continuously flushed with sample, at sampling depth, to equilibrate the
                              system, and (5) the sample does not travel through long lengths of
                              tubing  that are more difficult to clean and keep clean (Reference
                              14.14). In addition, the device is designed to eliminate atmospheric
                              contact with the sample during collection.

               6.5.1.2        To assemble the cleaned jar sampler, screw the torpedo weight onto
                              the machined bolt attached to the support plate of the jar sampler.
                              Attach a section of the 1/4-inch OD tubing to the jar by inserting the
                              tubing  into the fitting on the lid and pushing down into the jar until
                              approximately 8 cm from the bottom.  Tighten the fitting nut securely.
                              Attach the solid safety line to the jar sampler using a bowline knot to
                              the loop affixed to the support  plate.

               6.5.1.3        For the tubing connecting the pump to the sampler, tubing lengths  of
                              up to 12 meters have been used successfully (Reference 14.14).

       6.5.2   Continuous-flow sampler (References 14.16 - 14.17)—This sampling system, shown in
               Figure 4, consists of a peristaltic or submersible pump and one or  more lengths of
               pre-cleaned fluoropolymer or styrene/ethylene/butylene/silicone (SEBS) tubing. A
               filter is added to the sampling train when sampling for dissolved metals.

               6.5.2.1        Advantages of this sampling system include (1) all  wetted surfaces  are
                              fluoropolymer or SEBS and can be readily cleaned, (2) the suction
                              device  is located in the boat, isolated from the sample bottle, (3) the
                              sample does not travel through long lengths of tubing that  are difficult
                              to clean and keep  clean,  and (4) in-line filtration is possible,
                              minimizing field handling requirements for dissolved metals  samples.

               6.5.2.2        Assembly of the system is performed in the field by the sampling team
                              as described in Section 8.2.8.   System components include an optional
                              polyethylene pole  to remove sampling personnel from the  immediate
                              vicinity of the sampling point and  the pump, tubing,  filter, and filter
                              holder  listed in Sections 6.14 and 6.15.

6.6    Field portable glove bag—I2R, Model R-37-37H (non-talc), or equivalent.  Alternately, a
       portable glove  box may be constructed with a non-metallic (PVC pipe or other suitable
       material) frame and a frame  cover made of an inexpensive, disposable, non-metallic material
       (e.g.,  a thin-walled polyethylene bag) (Reference 14.7).

6.7    Gloves—clean, non-talc polyethylene, latex, vinyl, or PVC; various lengths.  Shoulder-length
       gloves are needed if samples are to be collected by direct  submersion of the  sample  bottle into
       the water or when sampling  for mercury.

       6.7.1   Gloves, shoulder-length polyethylene—Associated Bag Co., Milwaukee, WI, 66-3-
               301, or equivalent.

       6.7.2   Gloves, PVC—Fisher Scientific Part No. 11-394-100B, or equivalent.
10                                                                                 December 1994

-------
                                                                                     Method 1669
 6.8    Storage bags—clean, zip:type, non-vented, colorless polyethylene (various sizes).

 6.9    Plastic wrap—clean, colorless polyethylene.
      »
 6.10   Cooler—clean, non-metallic for shipping samples.

 6.11   Ice or chemical refrigerant packs—to keep samples chilled in the cooler during shipment.

 6.12   Wind suit—Pamida, or equivalent.

        6.12.1  An unlined, long-sleeved wind suit consisting of pants and jacket and constructed of
               nylon or other synthetic fiber is worn when sampling for mercury to prevent mercury
               adsorbed onto cotton or other clothing materials from contaminating samples.

        6.12.2  Washing and drying—The wind suit is washed by  itself or with other wind suits only
               in a home or commercial washing machine and dried in a clothes drier.  The clothes
               drier must be thoroughly vacuumed, including the lint filter, to remove all traces of
               lint prior to drying. After drying, the wind suit is folded and stored in a clean,
               polyethylene bag for shipment to the sample site.

6.13    Boat

        6.13.1  Only metal-free (e.g.,  fiberglass) boats should be used, along with wooden or
               fiberglass oars. A flat-bottom, Boston Whaler type boat is preferred because sampling
               materials can be stored with reduced chance of tipping over.  Gasoline or diesel fueled
        '       boat motors should be avoided when possible because the exhaust can be a source of
               contamination. If the body of water is so large as to necessitate the use  of a boat
               motor, the engine should be shut off at a distance  far enough from the sampling point
               as to avoid contamination, and the sampling team should manually propel the boat to
               the sampling point. Samples should be collected upstream of boat movement.

        6.13.2  Before first use, the boat should be cleaned and stored in an area that minimizes
               exposure to dust and atmospheric particles.  For example, cleaned boats should not be
               stored in an area that would, allow exposure to automobile exhaust or industrial
               pollution.

       -6.13.3  The boat should be frequently visually inspected for possible contamination.
               Immediately before use, the boat should be washed down with water from the
               sampling site away from any sampling points to  remove any dust or dirt accumulation.

        6.13.4  After sampling, the boat should be returned to the laboratory or cleaning facility,
               cleaned as necessary, and stored away from any  sources of contamination until next
               use.

6.14    Filtration Apparatus—Required when collecting samples  for dissolved metals determinations.

        6.14.1  Filter—0.45 /mi, 15 him diameter or larger, tortuous path capsule filters (Reference
               14.18),  Gelman Supor 12175, or equivalent.
December 1994                                                                                 11

-------
Method 1669
        6.14.2 Filter holder for mounting filter to the gunwale of the boat—Rod or pipe made from
               plastic material and mounted with plastic clamps. Note: A filter holder may not be
               required if one or a few samples are to be collected. For these cases, it may only be
               necessary to attach the filter to the outlet of the tubing connected to the pump.

6.15    Pump and pump apparatus—Required for use with the jar sampling system (Section 6.5.1) or
        the continuous flow sytem (Section 6.5.2). Peristaltic pump—115  a.c, 12 volt d.c., internal
        battery, variable speed, single-head, Cole-Parmer, portable, "Masterflex L/S", Catalog No.
        H-07570-10 drive with Quick Load pump head, Cat. No. H-07021-24, or equivalent. (Note:
        equivalent pumps may include rotary vacuum, submersible,  or other  pumps suitable to meet
        the site-specific depth sampling needs.)

        6.15.1  Cleaning—Peristaltic pump modules do not require cleaning.   However,  nearly all
               peristaltic pumps contain a metal head and metal controls.  Touching the head or
               controls necessitates changing of gloves before touching the Apparatus.  If a
               submersible pump is used, then a large quantity of .reagent water should  be passed
               through the pump in order to clean the stainless steel shaft (hidden behind the
               impeller) that comes in contact with the sample.  Users of  such pumps should
               recognize, however, that even with such cleaning, a stainless steel impeller may
               present contamination problems when sampling for certain metals (such as  chromium);
               in these cases, an alternate type of pump must be used.

        6.15.2 Tubing for use with peristaltic pump—SEES resin, approximately 3/8 inch ID by
               approximately 3 ft, Cole-Parmer size  18, Cat. No. G-06464-18, or approximately 1/4
               inch ID, Cole-Parmer size 17, Cat. No. G-06464-17, or equivalent. Tubing is
               cleaned by soaking in 5 - 10 percent HC1 solution for 8 - 24  h, rinsing with reagent
               water in a clean bench in a clean room, and drying in the clean bench by purging with
               mercury-free air or nitrogen.  After drying,  the tubing is double-bagged in clear
               polyethylene bags, serialized with a unique number, and stored until use.

        6.15.3  Tubing for connection to peristaltic pump tubing—fluoropolymer, 3/8 inch  or 1/4 inch
               OD, in lengths as required to reach the point of sampling.  If sampling will be at
               some depth from the end of a boom extended from a boat,  sufficient tubing to extend
               to the end of the boom and to the depth will be required.  Cleaning of PTFE can be
               the same as cleaning the tubing for the rotary vacuum pump  (Section 6.15.1.2).  If
               necessary, more agressive cleaning (e.g., concentrated nitric  acid) may be used.

        6.15.4 Batteries to operate pump—12 volt, 2.6 amp, gel cell, YUASA NP2.6-12,  or
               equivalent.  A 2-amp  fuse connected at the positive battery terminal is strongly
               recommended  to prevent short circuits from overheating the battery. A 12-volt, lead-
               acid automobile or marine battery may be more suitable for extensive pumping.

        6.15.5 Tubing connectors—appropriately sized PVC, clear polyethylene, or fluoropolymer
               "barbed" straight connectors cleaned as the tubing above.  Used to connect multiple
               lengths of tubing.                    .

6.16    Carboy for collection and storage  of dilute waste acids used to store  bottles.
12                                                                                December 1994

-------
                                                                                     Method 1669
 6.17   Apparatus for field preservation of aliquots for trivalent chromium determinations

        6.17.1 Fluoropolymer forceps,, 1-L fluoropolymer jar, and 30-mL fluoropolymer vials with
               screw caps (1 vial per sample and blank).  It is recommended that 1 mL of ultra-pure
               nitric acid (Section 7.3) be added to each vial prior to transport to the field in order to
               simplify field handling activities (See Section 8.4.4.6).

        6.17.2 Filters—0.4 micron,  47-mm polycarbonate Nucleopore (or equivalent). Filters are
               cleaned as follows. Fill a 1-L fluoropolymer jar approximately 2/3 full with 1-N
               nitric acid.  Using fluoropolymer forceps, place individual filters in the fluoropolymer
               jar.  Allow the filters to soak for 48 hours.  Discard the acid, and rinse five times
               with reagent water.  Fill the jar with reagent water, and soak the filters for 24 hours.
               Remove the filters when ready for use, and using fluoropolymer forceps,  place them
               on the filter apparatus (Section 6.17.3).

        6.17.3 Vacuum filtration apparatus— Millipore 47  mm size, or equivalent, vacuum pump and
               power source (and extension cords,  if necessary) to operate the pump.

        6.17.4 Eppendorf auto pipet and colorless pipet tips (100 - 1,000 /zL)

        6.17.5 Wrist-action shaker—Burrel or equivalent.

        6.17.6 Fluoropolymer wash bottles—one filled with reagent water (Section 7.1) and one filled
               with high purity 10% HC1 (Section 7.4.4), for  use in rinsing forceps and pipet tips.

7.0     REAGENTS AND STANDARDS

7.1     Reagent water—water in which the analytes of interest  and potentially interfering substances
        are not detected at the Method Detection Limit (MDL)  of the analytical method used for
        analysis of samples. Prepared by distillation, deionization, reverse osmosis, anodic/cathodic
        stripping voltammetry, or other  techniques that remove the metal(s) and potential
        interferent(s).  A large carboy or other appropriate container filled with reagent water must be
        available for the collection of field blanks.

7.2     Nitric acid, dilute, trace-metal grade—Shipped with sampling kit for cleaning equipment
        between samples.

7.3     Sodium hydroxide—For use when field preserving samples for hexavalent chromium
        determinations (Section 8.4.5).

7.4     Reagents for field processing aliquots for trivalent chromium determinations

        7.4.1   Nitric acid, ultra-pure—For use when field preserving  samples for trivalent chromium
               determinations (Sections 6.17 and 8.4.4).

        7.4.2   Ammonium iron (II)  sulfate solution (0.01M)—Used to prepare the chromium (III)
               extraction solution (Section 7.4.3) necessary for field preservation of samples for
               trivalent chromium (Section  8.4.4).  Prepare the ammonium iron (II) sulfate solution
December 1994                                                                                 13

-------
Method 1669
               by adding 3.92 g ammonium iron (II) sulfate (ultrapure grade) to a 1-L volumetric
               flask.  Bring to volume with reagent water.  Store in a clean polyethylene bottle.

        7.4.3   Chromium (HI) extraction solution—For use when field preserving samples for
               trivaleht Chromium determinations (Section 8.4.4). Prepare this solution by adding
               100 mL of ammonium iron (II) sulfate solution (Section 7.4.2) to a 125-mL
               polyethylene bottle. Adjust pH to 8 with approximately 2 mL of ammonium
               hydroxide solution.  Cap and shake on a wrist-action shaker for 24 hours.. This iron
               (III) hydroxide solution is stable for 30 days.

        7.4.4   Hydrochloric acid—High purity, 10% solution—shipped with sampling kit  in
               fluoropolymer wash bottles for cleaning triyalent chromium sample preservation
               equipment between samples.

        7.4.5   Chromium stock standard solution (1000 /*gAnL)-Prepared by adding 3.1 g, anhydrous
               chromium chloride to a 1-L flask and diluting to volume with 1 % hydrochloric acid.
               Store in polyethylene bottle.  A commercially available standard solution may be
               substituted.

        7.4.6   Standard chromium spike solution (1000 /zg/L)-Used  to spike sample aliquots for
               matrix spike/matrix spike duplicate (MS/MSD) analysis and to prepare ongoing
               precision and recovery standards.  Prepared by spiking 1 mL of the chromium stock
               standard solution (Section 7.4.5) into a 1-L flask. Dilute to volume with 1% HC1.
               Store in a polyethylene bottle.

        7.4.7.   Ongoing precision and recovery (OPR) standard (25 /ig/L)-Prepared  by spiking 2.5
               mL of the standard chromium spike solution (Section  7.4.6) into a 100-mL flask.
               Dilute to volume with 1% HC1.  One OPR is required for every ten samples.
8.0    SAMPLE COLLECTION, FILTRATION, AND HANDLING

8.1    Site selection

       8.1.1   Selection of a representative site for surface water'sampling is based on many factors
               including:  study objectives, water use, point source discharges, nonpoint source
               discharges, tributaries, changes in stream characteristics, types of stream bed, stream
               depth, turbulence, and the presence of structures (bridges, dams, etc.).  When
               collecting samples to determine ambient levels of trace metals,  the presence of
               potential sources of metal contamination are of extreme importance in site selection.

       8.1.2   Ideally, the selected sampling site will exhibit a high degree of cross-sectional
               homogeneity. It may be possible to use previously collected data to identify  locations
               for samples that are well-mixed or are vertically or horizontally stratified.  Since
               mixing is principally governed by turbulence and water velocity, the selection of a site
               immediately  downstream of a riffle area will ensure good vertical mixing.  Horizontal
               mixing occurs in constrictions in the channel. In the absence of turbulent areas, the
               selection of a site that  is clear of immediate point sources, such as industrial  effluents,
               is preferred for  the collection of ambient water samples (Reference  14.19).
14                                                                        .         December 1994

-------
                                                                                     Method 1669
        8.1.3  In order to minimize atmospheric trace metals contamination, ambient water samples
               should be collected from sites that are as far as possible (e.g., at least several hundred
               feet) from any metal supports, bridges, wires or poles.  Similarly, samples should be
               collected as far as  possible from regularly or heavily traveled roads.  If it is not
               possible to avoid collection near roadways,  it is advisable to study traffic patterns and
               plan sampling events during lowest traffic flow (Reference 14.7).

        8.1.4  The sampling activity should be planned to  collect samples known or suspected to
               contain the lowest  concentrations of trace metals first, finishing with the  samples
               known or suspected to contain the highest concentrations.  For example,  if samples
               are collected from  a flowing river or stream near an industrial or municipal discharge,
               the upstream sample should be collected first, the downstream sample collected
               second, and the sample nearest the discharge collected last.

8.2     Sample.collection procedure—Prior to collection of ambient water samples, consideration
        should be given to the type of sample to be collected, the amount of sample needed, and the
        devices to  be used (grab, surface, or subsurface samplers).   Sufficient sample volume should
        be collected to allow for necessary quality control analyses, .such as matrix spike/ matrix spike
        duplicate analyses.

        8.2.1   Four (4) sampling  procedures are described:

               8.2.1.1         Section 8.2.5 describes a procedure for collecting samples directly into
                              the sample container.  This procedure is the simplest and provides the
                              least potential for contamination because it requires the least amount
                              of equipment and handling.

               8.2.1.2         Section 8.2.6 describes a procedure for using a grab sampling device
                              to collect samples.

               8.2.1.3         Section 8.2.7 describes a procedure for depth sampling with a jar
                              sampler.  The size of sample container used is dependent on the
                              amount of sample needed by the analytical laboratory.

               8.2.1.4         Section 8.2.8 describes a procedure for continuous-flow sampling
                              using a submersible or peristaltic pump.

        8.2.2   The sampling team should ideally approach  the site  from down current and downwind
               in order to prevent contamination of the sample by particles sloughing off the  boat or
               equipment.   If it is not possible to approach from both, the site should be approached
               from down current if sampling from a boat or approached from downwind if sampling
               on foot. When sampling from a boat, the bow of the boat should be oriented  into the
               current (the boat will be pointed upstream).  All sampling activity should occur from
               the bow.

                      If the samples are being collected from a boat, it is recommended that the
                      sampling team create a stable workstation by arranging the cooler or shipping
                      container as a work table on the upwind side of the boat, covering this work
                      table and the upwind gunnel with plastic wrap or a plastic tablecloth, and
December 1994                                                                                 15

-------
Method 1669.
                       draping the wrap or cloth over the gunnel. If necessary, duct tape is used to
                       hold the wrap or cloth in place.

        8.2.3   All operations involving contact with the sample bottle and with transfer of the sample
               from the sample collection device to the sample bottle (if the sample is not directly
               collected in the bottle) are handled by the individual designated as "clean hands".
               "Dirty hands" is responsible for all activities that do not involve direct contact with
               the sample.

                       Initially, this appears to be a fairly clear-cut and separate division of
                       responsibilities. In fact, the completion of the entire protocol  may require a
                       good deal of coordination and practice (e.g.,  "dirty hands" must open the box
                       or cooler containing the sample bottle and unzip the outer bag; clean hands
                       must reach into the outer bag, open the inner bag, remove the bottle, collect
                       the sample, replace the bottle lid, put the bottle back into the inner bag, and
                       zip the inner bag.  Dirty hands must close the outer bag and place it  in a
                       cooler).

                       To minimize unnecessary confusion, it is recommended that a  third team
                       member be available to  complete the necessary sample documentation (e.g., to
                       document sampling location, time, sample number, etc).  Otherwise,  the
                       sample documentation activity must be performed by "dirty hands" (Reference
                       14.7).

        8.2.4   Extreme care must be taken during all sampling operations to minimize exposure of
               the sample to human, atmospheric, and other sources of contamination.  Care must be
               taken to avoid breathing directly on the sample, and whenever possible, the sample
               bottle should be opened; filled, and closed while submerged.

        8.2.5   Manual collection of surface samples directly into the sample bottle

               8.2.5.1        At the site, all sampling personnel must put on clean gloves (Section
                              6.7) prior to commencing sample collection activity, with "clean
                              hands" donning  shoulder-length gloves. If samples are to be  analyzed
                              for mercury, the sampling team must also put their pre-cleaned
                              windsuits on at this  time. Note that "clean hands" should put on the
                              shoulder-length polyethylene gloves (Section 6.7.1) and both  "clean
                              hands" and "dirty hands" should put on the PVC gloves (Section
                              6.7.2).

               8.2.5.2        "Dirty hands" must open the cooler or storage container,  remove the
                              double bagged sample bottle from storage, and unzip the outer bag.

               8.2.5.3        Next, "clean hands" opens the inside bag containing the sample bottle,
                              removes the bottle, and reseals the inside bag.  "Dirty hands" then
                              reseals the outer bag.
16   .                                                              .                December 1994

-------
                                                                                      Method 1669
                8.2.5.4         "Clean hands" unscrews the cap and, while holding the cap upside
                              down, discards the dilute acid solution from the bottle into a carboy
                              for wastes (Section 6.16).

                8.2.5.5         "Clean hands" then submerges the sample bottle, and allows the bottle
                              to partially fill with sample.  "Clean hands"  screws the cap on the
                              bottle, shakes the bottle several times, and empties the  rinsate away
                              from the site. After two more rinsings, "clean hands" holds the bottle
                              under water and allows bottle to fill with sample.  After the bottle has
                              filled (i.e., when no  more bubbles appear), and while the bottle is still
                              inverted so that the mouth of the bottle is underwater, "clean hands"
                              replaces the cap of the bottle.  In this way, the sample has never
                              contacted the air.

                8.2.5.6        Once the bottle lid has been replaced, "dirty hands" re-opens  the outer
                              plastic bag, and  "clean hands" opens the inside bag, places the bottle
                              inside it, and zips the inner bag.

                8.2.5.7        "Dirty hands" zips the outer bag.

                8.2.5.8        Documentation—after each sample is collected, the sample number is
                              documented in the sampling log, and any unusual observations
                              concerning the sample and the sampling are documented.

                8.2.5.9        If the sample is to be analyzed for dissolved metals, it is filtered in
                              accordance with the procedure described in Section 8.3.

        8.2.6   Sample collection with grab sampling device (Figure 1 and Section 6.4.1)—The
                following steps detail samle collection using the grab sampling device shown in Figure
                1 and described in Section 6.4.1. The procedure is indicative of the "clean
                hands/dirty hands" technique that must be  used with alternative grab sampling devices
                such as that shown in Figure 2 and described  in Section 6.4.2.

                8.2.6.1   .     The sampling team puts on gloves (and windsuits, if applicable) and
                              handles bottles as with manual collection (Sections 8.2.5.1 - 8.2.5.4
                              and 8.2.5.6 - 8.2.5.7).

                8.2.6.2        "Dirty hands" removes the sampling device from its storage container
                              and opens the outer polyethylene bag.

                8.2.6.3        "Clean hands" opens the inside polyethylene bag and removes the
                              sampling device.  Ideally, a sample bottle will have been pre-attached
                              to the sampling device in the class 100 clean room at the laboratory.
                              If it is necessary to attach a bottle to the device in the field "clean
                              hands" performs this operation, described in Section 6.4.2, inside the
                              field-portable glove bag (Section 6.6).

                8.2.6.4        "Clean hands" changes gloves.
December 1994                                                                                17

-------
Method 1669
               8.2.6.5        "Dirty hands" submerges the sampling device to the desired depth and
                              pulls the fluoropolymer pull-cord to bring the seal plate into the
                              middle position so that water can enter the bottle.

               8.2.6.6 '      When the bottle is full (i.e., when no more bubbles appear),  "dirty
                              hands" pulls the fluoropolymer cord to the final stop position to seal
                              off the sample and removes the sampling device from the water.

               8.2.6.7        "Dirty hands" returns the sampling device to its large inner plastic
                              bag,  "clean hands" pulls the bottle out of the collar, unscrews the
                              bottle from the sealing device, and caps the bottle.  "Clean hands" and
                              "dirty hands" then return the bottle to its double-bagged storage as
                              described in Sections 8.2.5.6 - 8.2.5.7.

               8.2.6.8        Closing mechanism:  "Clean hands" removes the closing mechanism
                              from the body of the grab sampler, rinses the device with reagent
                              water (Section 7.1),  places it inside a new clean plastic bag, zips the
                              bag, and places  the bag inside an outer bag held by "dirty hands".
                              "Dirty hands" zips the outer bag and places the double bagged closing
                              mechanism in the equipment storage box.

               8.2.6.9        Sampling device:  "Clean hands" seals the large inside bag containing
                              the collar, pole, and cord and places the bag  into a large outer bag
                              held by "dirty hands".  "Dirty hands" seals the outside bag and places
                              the double, bagged sampling device into the equipment storage box.

               8.2.6.10        Documentation—after each sample is collected, the sample number is
                              documented in the sampling log, and any unusual observations
                              concerning the sample and the sampling are documented.  .

               8.2.6.11        If the sample  is  to be analyzed for dissolved metals, it is filtered in
                              accordance with the  procedures described in Section 8.3.

       8.2.7   Depth sampling using ajar sampling device (Figure  3 and Section 6.5.1)

               8.2.7.1         The sampling team puts on gloves (and windsuits,  if applicable) and
                              handles bottles as with manual collection (Sections 8.2.5.1 - 8.2.5.4
                              and 8.2.5.6 - 8.2.5.7).

               8.2.7.2        "Dirty hands" removes the jar sampling device from its storage
                              container and opens the outer polyethylene bag.

               8.2.7.3        "Clean hands" opens the inside polyethylene bag arid removes the jar
                              sampling apparatus.   Ideally, the sampling device will have been pre-
                              assembled in  a class 100 clean room at the laboratory.  If, however, it
                              is necessary to assemble the device in the field, then "clean hands"
                              must perform this operation, described in Section 6.5.2, inside a field-
                              portable glove bag (Section 6.6).
18                                                               .                  December 1994

-------
                                                                                    Method 1669
               8.2.7.4        While "dirty hands" is holding the jar sampling apparatus, "clean
                              hands" connects the pump to the to the 1/4-inch OD flush line.

               8.2.7.5.        "Dirty hands" lowers the weighted sampler to the desired depth.

               8.2.7.6        "Dirty hands" turns on the pump allowing a large volume (>2 liters)
                              of water to pass through the system.

               8.2.7.7        After stopping the pump, "dirty hands" pulls up the line, tubing, and
                              device and places them into either a field-portable glove bag or a
                              large,  clean plastic bag as they emerge.

               8.2.7.8        Both "clean hands" and "dirty hands" change gloves.

               8.2.7.9        Using  the technique described in Sections 8.2.5.2 - 8.2.5.4, the
                              sampling team removes a sample bottle from storage, and "clean
                              hands" places the bottle into the glove bag.

               8.2.7.10    ,   "Clean hands" tips the sampling jar and dispenses the sample through
                              the short length of fluoropolymer tubing into the sample bottle.

               8.2.7.11    .    Once the bottle is filled, "clean hands" replaces the cap of the bottle,
                              returns the bottle to the inside polyethylene bag, and zips the bag.
                              "Clean hands" returns the zipped bag to the  outside polyethylene bag
                              held by "dirty hands".

               8.2.7.12        "Dirty hands" zips the outside bag.  If the sample is to be analyzed for
                              dissolved metals, it is filtered as described in Section 8.3.

               8.2.7.13        Documentation—after each sample is collected, the sample number is
                              documented in the sampling log, and any  unusual observations
                              concerning the sample and the sampling are documented.

       8.2.8   Continuous-flow sampling (Figure 4 and Section 6.5.2)—The continuous-flow
               sampling  system uses peristaltic pump (Section 6.15) to pump sample to the boat or  to
               shore  through the SEBS-resin or PTFE tubing.

               8.2.8.1         Prior to putting on wind suits or gloves, the  sampling team removes
                              the bags containing the pump (Section 6.15), SEBS-resin tubing
                              (Section 6.15.2), batteries (Section 6.15.4), gloves (Section 6.7),
                              plastic wrap (Section 6.9), wind suits (Section 6.12), and, if samples
                              are to be filtered, the filtration apparatus (Section 6.14) from the
                              coolers or storage containers in which they are packed.

               8.2.8.2        "Clean hands" and "dirty hands" put on the wind suits and PVC
                              gloves (Section 6.7.2).

               8.2.8.3        "Dirty hands" removes the pump from its storage bag, and opens the
                              bag containing the SEBS-resin tubing.
December 1994                                                                                19

-------
Method 1669
               8.2.8.4        "Clean hands" installs the tubing while "dirty hands" holds the pump.
                              "Clean hands" immerses the inlet end of the tubing in the sample
                              stream.

               8.2.8.5  '      Both "clean hands" and "dirty hands" change gloves.  "Clean hands"
                              also puts on shoulder length polyethylene gloves (Section 6.7.1).

               8.2.8.6        "Dirty hands" turns the pump on and allows the pump to run for 5 -
                              10 minutes or longer to purge the pump and tubing.

               8.2.8.7        If the sample is to be filtered, clean hands installs the filter at the end
                              of the tubing, and dirty hands sets up the filter holder on the gunwhale
                              as  shown in Figure 4.  Note:  The filtration apparatus is not attached
                            .  until immediately prior to sampling to prevent buildup of particulates
                              from clogging the filter.

               8.2.8.8        The sample is collected by rinsing the sample bottle and cap three
                              times  and collecting the sample from the  flowing stream.

               8.2.8.9        Documentation—after each sample is collected,  the sample number is
                              documented in the sampling log, and any unusual observations
                              concerning the sample and the sampling are documented.

8.3     Sample filtration—The filtration procedure described below is used for samples collected using
        the manual (Section 8.2.5), grab (Section 8.2.6), or jar (Section 8.2.7) collection systems
        (Reference 14.7). In-line filtration using the continuous-flow approach is described in Section
        8.2.8.7.  Because of the risk of contamination, it is recommended that samples for mercury
        be shipped unfiltered via overnight courier and filtered upon receipt at the laboratory.

        8.3.1   Set up the filtration system inside the glove bag, using the shortest piece of pump
               tubing as is practical.  Place the peristaltic pump  immediately outside of the glove bag
               and poke a small hole in the glove bag for passage of the tubing.  Also, attach a short
               length of tubing to the outlet of the capsule filter.

        8.3.2   "Clean hands" removes the water sample from the inner storage bag using the
               technique described in Sections 8.2.5.2 - 8.2.5.4  and places the sample inside the
               glove bag.  "Clean hands" also  places  two clean empty sample bottles, a bottle
               containing reagent  water, and a bottle for waste in the glove bag.

        8.3.3   "Clean hands" removes the lid of the reagent water bottle and places the end of the
               pump tubing in the bottle.

        8.3.4   "Dirty hands" starts the pump and passes approximately 200 mL of reagent water
               through the tubing and filter into the waste bottle. "Clean hands" then moves the
               outlet tubing to a clean bottle and collects the remaining reagent water as a blank.
               "Dirty hands" stops the pump.

        8.3.5   "Clean hands" removes  the lid of the sample bottle and places the intake end of the
               tubing in the bottle.
20                                                                                December 1994

-------
                                                                                      Method 1669
        8.3.6   "Dirty hands" starts the pump and passes approximately 50 mL through the tubing
                and filter into the remaining clean sample bottle and then stops the pump.  "Clean
                hands" uses the filtrate to rinse the bottle, discards the waste sample, and returns the
                outlet tube to the sample bottle.

        8.3.7   "Dirty hands" starts the pump and the remaining sample is processed through the
                filter and collected in the sample bottle.  If preservation is required, the sample is
                acidified at this point (Section 8.4).

        8.3.8   "Clean hands" replaces the lid on the bottle, returns the bottle to the inside bag, and
                zips the bag.  "Clean hands" then places the zipped bag ,into the outer bag held by
                "dirty hands."

        8.3.9   "Dirty hands" zips the outer bag, and places the double bagged sample  bottle into a
                clean, ice-filled cooler for immediate shipment to the laboratory.

        8.3.10  Note:  It is not advisable to re-clean and re-use filters.  The difficulty and risk
                associated with failing to properly clean these  devices far outweighs the cost of
                purchasing new equipment.

8.4     Preservation

        8.4.1    Field preservation is not necessary for  dissolved metals, except for trivalent and
               hexavalent chromium,  provided that the sample is preserved in the laboratory and
               allowed to stand for at least two days in order to allow the metals adsorbed to the
               container walls to  redissolve.  Field preservation is advised for hexavalent chromium
                in order to provide sample stability  for up to 30 days.  Mercury samples should be
               shipped via overnight courier and preserved upon receipt at the laboratory.

        8.4.2    If field preservation is  required,  preservation must be performed in the glove bag or
                in a designated clean area, with gloved hands,  as rapidly as possible to preclude
               particulates from contaminating the  sample.  For preservation of trivalent chromium,
                the glove bag or designated clean area  must be large enough to accomodate the
                vacuum filtration apparatus (Section 6.17.3), and an area should be available for
                setting up the wrist-action shaker (Section 6.17.5).  It is also advisable to set up a
                work area that contains a "clean" cooler for storage of clean equipment,  a "dirty"
                cooler for storage of "dirty" equipment, and a third cooler to store samples for
                shipment to the laboratory.

        8.4.3    Preservation .of aliquots for metals other than trivalent and hexavalent chromium:
                Using a disposable, pre-cleaned, plastic pipette, add 5 mL of a 10 percent solution of
               ultra-pure nitric acid in reagent water per liter of sample. This will be sufficient to
               preserve a neutral sample to pH  <2.

        8.4.4    Preservation of aliquots for trivalent chromium (References 14.8 - 14.9)

                8.4.4.1        Decant 100 mL of the sample  into a clean polyethylene bottle.
December 1994                                                                                 21

-------
Method 1669
               8.4.4.2        Clean an Eppendorf pipet by pipeting 1 mL of 10% HC1 (Section
                              (7.4.4) followed by 1 mL of reagent water into an acid waste
                              container.  Use the rinsed pipet to add 1 mL of chromium (III)
                              extraction solution (Section 7.4.3) to each sample and blank.

               8.4.4.3        Cap each bottle tightly, place in a clean polyethylene bag, and shake
                              on a wrist action shaker (Section 6.17.5) for 1  hour.

               8.4.4.4        Vacuum-filter the precipitate through a 0.4 /xm pretreated filter
                              membrane (Section 6.17.2),  using fluoropolymer forceps (Section
                              6.17.1) to handle the membrane, and a 47-mm vacuum filtration
                              apparatus with a precleaned  filter holder (Section 6.17.3). After all
                              sample has filtered, rinse the insides of the filter holder with
                              approximately 15 mL of reagent water.

               8.4.4.5        Using the fluoropolymer forceps, fold the membrane in half and then
                              in quarters, taking care to avoid touching the side containing the
                              filtrate to any surface.  (Folding is done while the membrane is sitting
                              on the filter holder and allows easy placement of the membrane into
                              the sample vial).  Transfer the filter to a 30-mL fluoropolymer vial.
                              If the fluoropolymer vial was not pre-equipped  with the ultra-pure
                              nitric acid (Section 7.4.1), rinse the pipet by drawing and discharging
                              1 mL of 10% HC1 followed  by 1 mL of reagent water into a waste
                              container, and add 1 mL of ultra-pure nitric acid to the sample vial.

               8.4.4.6        Cap the vial and double bag  it for shipment to the laboratory.

               8.4.4.7        Repeat steps  8.4.4.4 through 8.4.4.6 for each sample, rinsing the
                              fluropolymer forceps and the pipet with 10% high purity  HC1
                              followed by reagent water between samples.

       8.4.5   Preservation of aliquots for hexavalent chromium (Reference 14.20)

               8.4.5.1         Decant 125 mL of sample into a clean polyethylene bottle.

               8.4.5.2        Prepare an Eppendorf pipet by pipeting  1 mL of 10% HC1 (Section
                              7.4.4) followed by 1 mL of reagent water into an acid waste
                              container. Use the rinsed^pipet to add 1 mL NaOH to each  125-mL
                              sample and blank aliquot.

               8.4.5.3        Cap the vial(s) and double bag for shipment to  the  laboratory.
9.0    QUALITY ASSURANCE/QUALITY CONTROL

9.1    The sampling team shall employ a strict quality assurance/ quality control (QA/QC) program.
       The minimum requirements of this program include the collection of equipment blanks, field
       blanks, and field replicates. It is also desirable to include blind QC samples as part of the
       program. If samples will be processed for trivalent chromium determinations, the sampling
22                                                                               December 1994

-------
                                                                                     Method 1669
        team shall also prepare method blank, OPR, and MS/MSD samples as described in Section
        9.6.

 9.2   '  The sampling team is permitted to modify the sampling techniques described in this method to
        improve performance or reduce sampling costs, provided that reliable analyses of samples are
        obtained and that samples and blanks are not contaminated.  Each time a modification is made
        to the protocols, the sampling team is required to demonstrate that the modification does not
        result in contamination of field and equipment blanks.  The requirements for modification are
        given in Sections 9.3 and 9.4.  Because the  acceptability of a modification is based on the
        results obtained with the modification, the sampling team must work with an analytical
        laboratory capable of making trace metals determinations to demonstrate equivalence.

 9.3     Equipment Blanks

        9.3.1   Prior to the use of any sampling equipment at a given site, the laboratory or
               equipment  cleaning contractor is required to generate equipment blanks in order to
               demonstrate that the equipment is free from contamination.  Two types of equipment
               blanks are  required:  bottle blanks and sampling equipment blanks.

        9.3.2   Equipment blanks must be run on all equipment that will be used in the field.  If, for
               example, samples are to be collected using both a grab sampling device and the jar
               sampling device, then an equipment  blank must be run on both pieces of equipment.

        9.3.3   Equipment blanks are generated in the laboratory or at the equipment cleaning
               contractor's facility by processing reagent water through the equipment using the same
               procedures that are used in the field  (Section 8). Therefore, the "clean hands/dirty
               hands" technique utilized during field sampling should be followed when preparing
               equipment blanks at the laboratory or cleaning facility.

        9.3.4   Detailed procedures for collecting equipment blanks are given in the QC Supplement.

        9.3.5   The equipment blank must be analyzed using the procedures given  in the QC
               Supplement and the Referenced Methods. If any metal(s) of interest or any potentially
               interfering  substance is detected in the equipment blank at the minimum level
               specified in the QC  Supplement, the  source of contamination/ interference must be
               identified and removed.  The equipment must be demonstrated to be free from the
               metal(s) of interest before the equipment may be used in the field.

9.4     Field Blank

        9.4.1   In order to demonstrate that sample contamination has not occurred during field
               sampling and sample processing, at least one (1) field blank must be generated for
               every ten (10) samples  that are collected at a given site. Field blanks are collected
               prior to sample collection.

        9.4.2   Field blanks are generated by filling  a  large carboy or other appropriate container
               with reagent water (Section 7.1) in the laboratory, transporting the filled container to
               the sampling site, processing the water through each of the sample processing steps
               and equipment (e.g., tubing, sampling devices, filters, etc.)  that will be used in the
December 1994                                                                                23

-------
Method 1669
               field, collecting the field blank in one of the sample bottles, and shipping the bottle to
               the laboratory for analysis in accordance with the QC Supplement and Referenced
               Methods.  For example, manual grab sampler field blanks are collected by directly
             .  submerging a sample bottle into the water, filling the bottle, and capping.  Subsurface
               sampler field blanks are collected by immersing the tubing into the water and pumping
               water into a sample container.

        9.4.3   Filter the field blanks using the procedures described in Section 8.3.

        9.4.4   If it is necessary to acid clean the sampling equipment between samples (Section 10),
               a field blank should be collected after the cleaning procedures but before the next
               sample is collected.         -

        9.4.5   If trivalent chromium aliquots are processed, a separate field blank must be collected
               and processed through the sample preparation steps given in Sections 8.4.4.1 -
               8.4.4.6.

9.5     Field Duplicate

        9.5.1   In order to assess the precision of the field sampling and analytical processes, at least
               one (1) field duplicate sample must be collected for every ten (10) samples that are
               collected at a given site.

        9.5.2   The field duplicate is collected either by splitting a larger volume into two aliquots in
               the  glove box, by using a sampler with duel inlets that allows simultaneous collection
               of two samples, or by collecting two samples in rapid succession.

        9.5.3   Field duplicates for dissolved metals determinations must be processed through  the
             .  procedures described in Section 8.3.  Field duplicates for trivalent chromium must be
               processed through the sample preparation steps given in Sections 8.4.4.1 - 8.4.4.6.

9.6     Additional QC for Collection of Trivalent Chromium Aliquots

        9.6.1   Method Blank—The sampling team must prepare one method blank for every ten field
               samples, or one per sample set, whichever is more frequent.  Each method blank is
               prepared by performing the preparation steps given in Sections 8.4.4.1 - 8.4.4.6 on a
               100 mL aliquot of reagent water (Section 7.1).  Do not utilize the procedures in
               Section 8.3 to process the method blank through the 0.45 /xm filter (Section 6.14.1),
               even if samples are being collected for dissolved metals determinations.

        9.6.2   Ongoing Precision and Recovery (OPR)—The sampling team must prepare one  OPR
               for  every ten field samples, or one per sample set, whichever  is more frequent.  The
               OPR is prepared by performing the preparation steps given in Sections 8.4.4.1  -
               8.4.4.6 on the OPR standard (Section 7.4.7).  Do not utilize the procedures in Section
               8.3 to process the OPR through the 0.45 /xm filter (Section 6.14.1), even if samples
               are being collected for dissolved metals determinations.

        9.6.3   MS/MSD—The sampling team must prepare one MS and one MSD for every ten field
               samples, or one per sample set, whichever is more frequent.
24                                                                                December 1994

-------
                                                                                    Method 1669
               9.6.3.1        If through historical data, the background concentration of the sample
                              can be estimated, the MS and MSD samples should be spiked at a
                              level of 2 to 5 times the background concentration.

               9.6.3.2        For samples where the background concentration is unknown, the MS
                              and MSD samples should be spiked at a concentration of 25 fig/L.

               9.6.3.3        Prepare the matrix  spike sample by taking a 100-mL aliquot of
                              sample, spiking it with 2.5 mL of the standard chromium spike
                              solution (Section 7.4.6), and processing it through the sample
                              preparation steps given in Sections 8.4.4.1 - 8.4.4.6.

               9.6.3.4        Prepare the matrix spike duplicate sample by taking a second 100-mL
                              aliquot of the same sample, spiking it with 2.5 mL of the spike
                              solution, and processing it through the preparation steps given in
                              Sections 8.4.4.1 - 8.4.4.6.       '_

               9.6.3.5        If field samples are collected for dissolved metals determinations, it is
                              necessary to process an  MS and an MSD aliquot through the 0.45
                              filter as described in Section 8.3.
10.0    RE-CLEANING THE APPARATUS BETWEEN SAMPLES

10.1    Sampling activity should be planned so that samples known or suspected to contain the lowest
        concentrations of trace metals are collected first with the samples known or suspected to
        contain the highest concentrations of trace metals collected last.  In this manner, cleaning of
        the sampling equipment between samples in unnecessary.

10.2    If samples are collected from adjacent sites (e.g., immediately upstream or downstream),
        rinsing of the sampling Apparatus with water that is to be sampled should  be sufficient.
                                                                                   i
10.3    If it is necessary to cross a gradient (i.e., going from a high concentration sample back to a
        low concentration sample), such as might occur when collecting at a second site, then the
        following procedure  may be used to clean the sampling equipment between samples:

        10.3.1  In the glove  bag, and using the "clean hands/dirty hands" procedure in Section 8.2.5,
               process  the dilute nitric acid solution (Section 7.2) through the Apparatus.

        10.3.2  Dump the  spent dilute acid in the waste carboy or in the water body away from the
               sampling point.

        10.3.3  Process  one  liter of reagent water through the Apparatus to rinse the equipment and
               discard the spent water.

        10.3.4  Collect a field blank as  described in Section 9.4.

        10.3.5  Rinse the Apparatus with copious amounts of the ambient water sample and proceed
               with sample  collection.
December 1994             ,                                                                  25

-------
Method 1669
10.4    Procedures for re-cleaning trivalent chromium preservation equipment between samples are
        described in Section 8.4.4.
11.0   METHOD PERFORMANCE

       Samples were collected in the Great Lakes during the September - October 1994 period using
       the procedures in this sampling method.  Performance data from this and other activities will
       be added when testing is completed.
12.0   POLLUTION PREVENTION

12.1   The only materials used in this procedure that could be considered pollutants are the acids
       used in the cleaning of the Apparatus, the boat, and related materials.  These acids are used in
       dilute solutions in small amounts and pose little threat to the environment when managed
       properly.

12.2   Cleaning solutions containing acids should be prepared in volumes consistent with use to
       minimize the disposal of excessive volumes of acid.
13.0   WASTE MANAGEMENT

13.1   It is the sampling team's responsibility to comply with all,federal, state, and local regulations
       governing waste management, particularly the discharge regulations, hazardous waste
       identification rules, and land disposal restrictions; and to protect the air, water, and land by
       minimizing and controlling all releases from field operations.

13.2   The acidic solutions shipped in samples are at pH 2 - 3 and are therefore not classified as
       hazardous materials.  These solutions may be disposed in the water body being sampled well
       away from the sampling point with no risk to the environment.

13.3   For further information on waste management, consult "The Waste Management Manual for
       Laboratory Personnel"  and "Less is Better—Laboratory Chemical Management for Waste
       Reduction," available from the American Chemical Society's Department of Government
       Relations and Science Policy, 1155 16th Street N.W., Washington, D.C. 20036.

14.0   REFERENCES

14.1   Adeloju, S.B.; Bond, A.M., "Influence of Laboratory Environment on the Precision and
       Accuracy of Trace Element Analysis", Anal.  Chem. 1985,  57, 1728.

14.2   Berman, S.S.; Yeats, P.A., "Sampling of Seawater for Trace Metals", in CRCReviews in
       Analytical Chemistry 1985, 16.
26                        .                                                      December 1994

-------
                                                                                  Method 1669
 14.3    Bloom, N.S. "Ultra-Clean Sampling, Storage, and Analytical Strategies for the Accurate
        Determination of Trace Metals in Natural Waters", presented at the 16th Annual EPA
        Conference on the Analysis of Pollutants in the Environment, Norfolk, Virginia, May 5,
     •  1993.

 14.4    Bruland, K.W.,  "Trace Elements in Seawater," Chemical Oceanography 1983, 8, 157.

 14.5    Nriagu, J.O.; Larson, G.; Wong, H.K.T.; Azcue, J.M., "A Protocol for Minimizing
        Contamination in the Analysis of Trace Metals in Great Lakes Waters" J.  Great Lakes
        Research 1993, 19, 175.

 14.6    Patterson, C.C.; Settle, D.M.,  "Accuracy in Trace Analysis", in National Bureau of
        Standards Special Publication 422\ LaFleur, P.O., Ed., U.S. Government Printing Office,
        Washington, DC, 1976.

 14.7    "A Protocol for the Collection and Processing of Surface-Water Samples for Subsequent
        Determination of Trace Elements, Nutrients, and Major Ions in Filtered Water"; Office of
        Water Quality Technical Memorandum 94.09, Office of Water Quality, Water Resources
        Division, U.S. Geological Survey, Reston, VA, 22092, January 28 1994.

 14.8    Standard Operating Procedure No. 4-54, Revision 01, SOP for Concentration and Analysis of
        Chromium Species in Whole Seawater, Prepared by Battelle Ocean Sciences, Duxbury, MA
        for the U.S. Environmental Protection Agency Office of Marine Environmental Protection,
        Ocean Incineration Research Program.  1987.

 14.9    Cranston, R.E.; Murray, J.W., "The Determination of Chromium Species in Natural
        Waters", Anal. Chem. Acta 1978, 99, 275.

 14.10   Prothrd, Martha G.  "Office of Water Policy and Technical Guidance on Interpretation and
        Implementation of Aquatic Life Metals Criteria", EPA Memorandum to Regional Water
        Management and Environmental Services Division Directors, October 1, 1993.

 14.11   "Format for Method Documentation", Distributed by the EPA Environmental Monitoring
        Management Council, Washington, DC,  November 18, 1993.

 14.12   Windom, H.L; Byrd, J.T.; Smith, R.G., Jr.; Huan, F.,  "Inadequacy of NASQAN Data for
        Assessing Metal Trends in the Nation's Rivers", Environ. Sci. Technol. 1991, 25, 1137.

 14.13   Zief, M.; Mitchell, J.W., "Contamination Control in Trace Metals Analysis" in Chemical
       Analysis 1976; Vol. 47 Chapter 6.

 14.14   Phillips, H.; Shafer, M.; Dean, P.; Walker, M.; Armstrong, D. "Recommendations for Trace
        Metals Analysis of Natural Waters"; Wisconsin Department of Natural Resources: Madison,
        WI, May 1992.

 14.15   Hunt, C.D. In Manual of Biological and Geochemical Techniques in Coastal Areas; 2nd ed.;
        Lambert, C.E. and Oviatt, C.A., Eds.; Marine Ecosystems Research Laboratory; Graduate
        School of Oceanography;  The University of Rhode Island: Narragansett, RI,  MERL Series,
        Report No. 1, Chapter IV.
December 1994                                                                             27

-------
Method 1669
14.16   Flegal, Russell, Summer 1994 San Francisco Bay Cruise, apparatus and procedures witnessed
        and videotaped by William Telliard and Thomas Fieldsend, September 15 - 16, 1994.

14.17,   Watras, Carl, Wisconsin DNR procedures for mercury sampling in pristine lakes in
        Wisconsin, witnessed and videotaped by Dale Rushneck and Lynn Riddick, September 9 - 10,
        1994.

14.18   Horowitz, Arthur J., Kent A. Elrick, and Mark R. Colberg, "The Effect  of Membrane
        Filtration Artifacts on Dissolved Trace Element Concentrations"  1992,  Wat. Res. 26, 753.

14.19   Engineering Support Branch Standard Operating Procedures and Quality Assurance Manual:
        1986; U.S. Environmental Protection Agency.  Region IV. Environmental Services Division:
        Athens, Georgia.

14.20   Grohse, Peter, Research Triangle Institute, Institute Drive, Building 6,  Research Triangle
     .   Park, NC 27709.

14.21   Methods 1624 and 1625, 40-CFR Part 136, Appendix A.
15.0   GLOSSARY OF DEFINITIONS AND PURPOSES

       These definitions and purposes are specific to this sampling method but have been conformed
       to common usage as much as possible.

15.1   Apparatus — The sample container and other containers, filters, filter holders, labware,
       tubing, pipettes, and other materials and devices used for sample collection or sample
       preparation, and that will contact samples, blanks, or analytical standards.

15.2   Equipment blank — An aliquot of reagent water that is subjected in the laboratory to all
       aspects of sample collection and analysis, including contact with all sampling devices and
       apparatus.  The purpose of the equipment blank is determine if the sampling devices and
       apparatus for sample collection have been adequately cleaned prior to shipment to the field
       site.  An acceptable equipment blank must be achieved before the sampling devices and
       apparatus are used for sample collection.

15.3   Field blank — An aliquot  of reagent water that is placed in a sample container in the
       laboratory, shipped to the field, and treated as a sample in all respects, including contact with
       the sampling devices and exposure to sampling site conditions, filtration, storage,
       preservation, and all analytical procedures.  The purpose of the field blank is to determine if
       the field or sample transporting procedures and environments have contaminated the sample.

15.4   Field duplicates (FD1 and FD2) — Two identical aliquots of a sample collected  in separate
       sample bottles at the same time and place under identical circumstances using a duel inlet
       sampler or by splitting a larger aliquot and treated exactly the same throughout field and
       laboratory  procedures.  Analyses of FD1  and FD2 give a measure of the precision associated
       with sample collection,  preservation, and storage, as well as with laboratory procedures.
28                                                    -                           December 1994

-------
                                                                                  Method 1669
 14.3    Bloom, N.S. "Ultra^Clean Sampling, Storage, and Analytical Strategies for the Accurate
        Determination of Trace Metals in Natural Waters", presented at the 16th Annual EPA
        Conference on the Analysis of Pollutants in the Environment, Norfolk, Virginia, May 5,
     •  1993.        ...

 14.4    Bruland, K.W.,  "Trace Elements in Seawater," Chemical Oceanography 1983, 8, 157.

 14.5    Nriagu, J.O.; Larson, G.; Wong, H.K.T.; Azcue, J.M., "A Protocol for Minimizing
        Contamination in the Analysis of Trace Metals in Great Lakes Waters" J. Great Lakes
        Research 1993, 19, 175.

 14.6    Patterson, C.C.; Settle, D.M.,  "Accuracy in Trace Analysis",  in National Bureau of
        Standards Special Publication422; LaFleur, P.O., Ed., U.S. Government  Printing Office,
        Washington, DC, 1976.

 14.7    "A Protocol for the Collection and Processing of Surface-Water Samples for Subsequent
        Determination of Trace Elements, Nutrients, and Major Ions in Filtered Water"; Office of
        Water Quality Technical Memorandum 94.09, Office of Water Quality, Water Resources
        Division, U.S. Geological Survey, Reston, VA, 22092, January 28 1994:

 14.8    Standard Operating Procedure No. 4-54, Revision 01, SOP for Concentration and Analysis of
        Chromium Species in Whole Seawater, Prepared by Battelle Ocean Sciences, Duxbury, MA
        for the U.S. Environmental Protection Agency Office of Marine Environmental Protection,
        Ocean Incineration Research Program.  1987.

 14.9    Cranston, R.E.; Murray, J.W., "The Determination of Chromium Species in Natural
        Waters", Anal. Chem. Ada 1978, 99, 275.   •

 14.10   Prothrd, Martha G.  "Office of Water Policy and Technical Guidance on Interpretation and
        Implementation of Aquatic Life Metals Criteria", EPA Memorandum to Regional Water
        Management and Environmental Services Division Directors, October 1, 1993.

 14.11   "Format for Method Documentation", Distributed by the EPA Environmental Monitoring
        Management Council, Washington, DC,  November 18, 1993.

 14.12   Windom, H.L; Byrd, J.T.; Smith, R.G., Jr.; Huan, F., "Inadequacy of NASQAN Data for
        Assessing Metal Trends in the Nation's Rivers", Environ. Sci. Technol. 1991, 25, 1137.

 14.13   Zief, M.; Mitchell, J.W., "Contamination Control in Trace Metals Analysis" in Chemical
       Analysis 1976; Vol. 47 Chapter 6.

 14.14   Phillips, H.; Shafer, M.; Dean, P.; Walker, M.; Armstrong, D. "Recommendations for Trace
        Metals Analysis of Natural Waters"; Wisconsin Department of Natural Resources: Madison,
        WI, May 1992.

 14.15   Hunt, C.D.  In Manual of Biological and Geochemical Techniques  in Coastal Areas;  2nd ed.;
        Lambert, C.E. and Oviatt, C.A., Eds.; Marine Ecosystems Research Laboratory; Graduate
        School of Oceanography;  The University of Rhode Island: Narragansett, RI, MERL Series,
        Report No.  1, Chapter IV.
December 1994                                                                             27

-------
Method 1669
14.16   Flegal, Russell, Summer 1994 San Francisco Bay Cruise, apparatus and procedures witnessed
        and videotaped by William Telliard and Thomas Fieldsend, September 15 - 16, 1994.

14.17   Watras, Carl, Wisconsin DNR procedures for mercury sampling in pristine lakes in
        Wisconsin, witnessed and videotaped by Dale Rushneck and Lynn Riddick, September 9 - 10,
        1994.

14.18   Horowitz, Arthur J., Kent A. Elrick, and Mark R. Colberg, "The Effect of Membrane
        Filtration Artifacts on Dissolved Trace Element Concentrations"  1992,  Wat. Res. 26, 753.

14.19   Engineering Support Branch Standard Operating Procedures and Quality Assurance Manual:
        1986; U.S. Environmental Protection Agency.  Region IV. Environmental Services Division:
        Athens, Georgia.

14.20   Grohse, Peter, Research Triangle Institute, Institute Drive, Building 6,  Research Triangle
        Park, NC 27709.

14.21   Methods 1624 and 1625, 40 CFR Part 136, Appendix A.
15.0   GLOSSARY OF DEFINITIONS AND PURPOSES

       These definitions and purposes are specific to this sampling method but have been conformed
       to common usage as much as possible.

15.1   Apparatus — The sample container and other containers, filters, filter holders, labware,
       tubing, pipettes, and other materials and devices used for sample collection or sample
       preparation, and that will contact samples, blanks, or analytical standards.

15.2   Equipment blank — An aliquot of reagent water that is subjected in the laboratory to all
       aspects of sample collection and analysis, including  contact with all sampling devices and
       apparatus.  The purpose of the equipment blank is determine if the sampling devices and
       apparatus for sample collection have been adequately cleaned prior to shipment to the field
       site.  An acceptable equipment blank must be achieved before the sampling devices  and
       apparatus are used for sample collection.

15.3   Field blank — An aliquot of reagent water that is placed in a sample container in the
       laboratory, shipped to the field, and treated as a sample in all respects, including contact with
       the sampling devices and exposure to sampling site conditions, filtration, storage,
       preservation, and all analytical procedures. The purpose of the field blank is to determine if
       the field or sample transporting procedures and environments have contaminated the sample.

15.4   Field duplicates (FD1 and FD2) — Two identical aliquots of a sample collected in separate
       sample bottles at the same time and place under identical circumstances using a duel inlet
       sampler or by splitting a larger aliquot and treated exactly the same throughout field and
       laboratory procedures.  Analyses of FD1 and FD2 give a measure of the precision associated
       with sample collection, preservation, and storage, as well as with laboratory procedures.
28                                                                               December 1994

-------
                                                                                      Method 1669
 15.5   Matrix spike (MS) and matrix spike duplicate (MSD) — Aliquots of an environmental sample
        to which known quantities of the analytes are added in the laboratory.  The MS and MSD are
        analyzed exactly like a sample.  Their purpose is to quantify the bias and precision caused by
      '  the sample matrix.   The background concentrations of the analytes in the sample matrix must
        be determined in a separate aliquot and the measured values in the MS and MSD corrected for
        background concentrations.

 15.6   May — This action,  activity, or procedural step is neither required nor prohibited.

 15.7   May not — This action, activity, or procedural step is prohibited.

 15.8   Minimum level (ML) — The lowest level at which the entire analytical system gives a
        recognizable signal and acceptable calibration point (Reference 14.21)

 15.9   Must — This action, activity, or procedural step is required.

 15.10  Reagent water — Water demonstrated to be free from the metal(s) of interest and potentially
        interfering substances at the MDL for that metal in the Referenced Method or Additional
        Method.

 15.12  Should —   This action, activity, or procedural step is suggested but not required.

 15.13  Trace-metal grade — Reagents which have been demonstrated to be free from the metal(s) of
        interest at  the method detection limit (MDL) of the analytical method to be used for
        determination of this  metal(s).

        Note: the term "trace-metal grade" has been used in place of "reagent grade" or "reagent"
        because acids and other materials labeled  "reagent grade" have been shown to contain
        concentrations of metals that will interfere in the determination of trace metals at ambient
        water quality criteria levels.
December 1994                                                                                 29

-------
                                                       Table 1
  List of Analytes Amenable to Collection Using Method 1669:  Lowest Water Quality Criterion for Each
 Metal Species,  Applicable EPA Methods, Analytical Techniques, Method Detection Limits, and Minimum
                                            Levels for the EPA Methods
Key:
Notes:
1.
2.

3.
Metal
Antimony
Arsenic
Cadmium
Chromium (III)
Chromium (VI)
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
' Lowest EPA
Water Quality
Criterion
0«g/L)'
14
0.018
0.32
57
10.5
2.5
0.14
0.012
7.1
5
0.31
1.7
28
EPA Method, analytical technique, and MDL/ML in pg/L
Method
200.8
200.9
—
200.8
200.9
200.10
200.13
...
218.6
200.8
200.10
200.8
200.10
200.13
—
200.8
200.9
200.10
200.8
200.9
200.8
200.8
200.8
200.9
Technique
ICP/MS
STGFAA
-,-'-
ICP/MS
STGFAA
CC/ICP/MS
CC/STGFAA
—
Ion Chrom.
ICP/MS
CC/ICP/MS
ICP/MS
CC/ICP/MS
CC/STGFAA
'
ICP/MS
STGFAA
CC/ICP/MS
ICP/MS
STGFAA
ICP/MS
ICP/MS
ICP/MS
STGFAA
MDL2
0.007
0.34
—
0.025
0.013
0.00094
0.0029
...
0.23
0.043
0.0083
.0.015
0.0039
0.012
—
0.33
0.65
0.013
1.2
0.69
0.018
0.007
0.069
0.10
ML1
0.02
1
—
O.I
0.05
0.002
0.01
—
0.5
0.1
0.02
0.05
0.01
0.05
—
1
2
0.05
5
2
0.05
0.02
0.2
0.2
ICP      =  Inductively coupled plasma                      Ion chrom
AES     =  Atomic emission spectrometry                   CC
MS      =  Mass spectrometry       •                      CVAF
GFAA   =  Graphite furnace atomic absorption spectrometry  •  STGFAA
Ion chromatography
Chelation/concentration
Cold vapor atomic fluorescence
Stabilized temperature GFAA
Lowest of the freshwater, marine, and human health WQC promulgated by EPA for 14 states at 40 CFR Part 131 (57 FR 60848),
with hard ness-dependent freshwater aquatic life criteria adjusted in accordance with 57 FR 60848 to reflect the worst case hardness
of 25 mg/L CaCO) and all aquatic life criteria adjusted in accordance with the 10/1/93 Office of Water guidance to reflect dissolved
metals criteria. A complete listing of all WQC, including total, dissolved, and levels calculated with a hardness of 25 mg/L CaCO,
and a hardness of 100 mg/L CaCO, is provided in Appendix A:

Method Detection Limit as determined by 40 CFR Part 136; Appendix B.

Minimum Level (ML) calculated by  multiplying laboratory-determined MDL by 3.18 and rounding result to nearest multiple of 1,
2, 5, 10, 20, 50 etc. in  accordance  with procedures utilized by EAD and described  in the EPA Draft National Guidance for the
Permitting, Monitoring, and Enforcement of Water Quality-Based Effluent Limitations Set Below Analytical Detection/Quantitation
Levels, March 22, 1994.
30
                                                                                                      December 1994

-------
                                   Figure 1 • Grab Sampling Device
Teflon Sealing
 Mechanism —.
  Tenon
Pull  Cord
                           500  ml*
                            Teflon
                            Bottle
                                              31

-------
 Figure 2 - Grab Sampling Device
         2.5cm PVC  ROD
           1
   5.1 cm
PVC  PIPE
PVC  ROD
   T
  46cm
   1
 PVC
PLATE


          IBcni
        H8cnH
            32

-------
   Figure 3 • Jar Sampling Device
Support
(Ttflon)
       \
                                   Teflon
                                   Support
                                   PUU
1/4' Tubing
T« Surftct
Pump
(Ttflon)
                                  I L T«flon
                                  /•r
                  Ttflon Torptdo
                  Vttiht
              33

-------
                                Figure 4 - Sample Pumping System
               Teflon
               Tubing
 Fiberglass
 Pole
Cable Ties
          Peristaltic
C-Flex    Pump
Tubing
Tubing
Adaptor
                                                           Filter
                                                           Cartridge
                                                                                 Clamp
                                                     Ring Stand
                                Teflon Weight
                                            34

-------
                   SECTION 3

  Quality Control Supplement for Determination of
     Trace Metals at EPA Water Quality Criteria
         Levels Using EPA Metals Methods

EPA Office of Water, Engineering & Analysis Division

-------
Quality Control Supplement for Determination of Trace Metals at EPA
      Water Quality Criteria Levels Using EPA Metals Methods
                        December 1994
              U.S. Environmental Protection Agency
                        Office of Water
                Office of Science and Technology
             Engineering and Analysis Division (4303)
                        401 M St. SW
                    Washington, DC 20460

-------
 QC Supplement for Determination of Trace Metals at EPA WQC'Levels
Acknowledgements

This quality control (QC) supplement was prepared under the direction of William A. Telliard of the U.S.
Environmental Agency's (EPA's) Office of Water (OW), Engineering and Analysis Division (EAD). The
supplement was prepared under EPA Contract 68-C3-0337 by the Environmental Programs Division of
DynCorp Environmental, with the assistance of Interface, Inc.

The following researchers in marine chemistry contributed to the philosophy behind this supplement.
Their contribution is gratefully acknowledged:

Shier Berman, National Research Council, Ottawa, Ontario, Canada;
Nicholas Bloom, Frontier Geosciences Inc, Seattle, Washington;
Paul Boothe and Gary Steinmetz, Texas A&M University, College State, Texas;
Eric Crecelius, Battelle Marine Sciences Laboratory, Sequim, Washington;
Russell Flegal, University of California/Santa Cruz, California;
Gary Gill, Texas A&M University at Galveston, Texas;
Carlton Hunt and Dion Lewis, Battelle Ocean Sciences, Duxbury, Massachusetts;
Carl Watras,  Wisconsin Department of Natural Resources, Boulder Junction, Wisconsin; and
Herb Windom and Ralph Smith, Skidaway Institute of Oceanography, Savannah, Georgia.

Additional support was provided by Ted Martin of the EPA Office of Research and Development's
Environmental Monitoring Systems Laboratory in Cincinnati, Ohio.
Disclaimer

This supplement has been  reviewed  and  approved for publication by the Engineering and Analysis
Division of the U.S. Environmental Protection Agency. Mention of trade names or commercial products
does not constitute endorsement or recommendation for use.

-------
	QC Supplement for Determination of Trace Metals at EPA WQC Levels


1.0    SCOPE AND APPLICATION

1.1    This document (hereinafter referred to as the  "QC  Supplement")  is designed to  aid  in the
       determination of metals at EPA water quality criteria (WQC) levels using the EPA methods listed
       in Section  1.2 below.  Use of these EPA methods to determine metals at EPA WQC levels
       requires the use of stringent quality control (QC) procedures to avoid contamination and ensure
       the validity of analytical results during sampling and analysis.  Therefore, this QC Supplement
       describes the QC procedures necessary to assure that contamination will be detected when blanks
       that accompany samples are analyzed. This QC Supplement is accompanied by Method 1669:
       Sampling Ambient Water for Determination of Trace Metals at EPA Water Quality Criteria Levels
       (hereinafter referred to as the "Sampling Method"). The Sampling Method is necessary to assure
       that trace metals determinations will not be compromised by contamination during the sampling
       process.

1.2    The increased QC procedures  described in this QC  Supplement are applicable to the following
       EPA methods and method compendium* (hereinafter referred to as the "Referenced Methods"):

       1.2.1   Five methods documented in Methods for the Determination of Metals in Environmental
              Samples (EPA/600/4-91/010), revised June 1991;  available from the National Technical
              Information  Service (NTIS), Springfield, VA 22161,  800-553-6847, as publication
              number PB 92-231498. These five methods are:

              1.2.1.1         Method 200.7  Metals in Water by ICP/AES
              1.2.1.2         Method 200.8 Metals in Water by ICP/MS
              1.2.1.3         Method 200.9 Metals in Water by STGFAA
              1.2.1.4         Method 200.10  Metals in Water by Chelation/Concentration ICP/MS
              1.2.1.4         Method 218.6 Hexavalent Chromium in Water by Ion Chromatography

       1.2.2   Two methods documented in Methods for the Determination of Chemical Substances in
              Marine and Estuarine Environmental Samples (EPA/600/R-92/121),  November  1993,
              NTIS PB 93-182913.  These two methods are:

              1.2.2.1         Method 200.10  Metals in Water by Chelation/Concentration ICP/MS
              1.2.2.2         Method 200.13  Metals in  Marine Water by Chelation/Concentration
                             GFAA

1.3    The Referenced Methods are not included in this QC Supplement.

1.4    This QC Supplement is required for use  with the Referenced Methods  when analyzing water
       samples at EPA WQC levels for dissolved metals.  Table 1 lists the Referenced Methods that
       achieve or most closely approach EPA WQC levels, the Method Detection Limit (MDL) for each
       metal,  and  the Minimum Level (ML, see Section  2.3) set for each metal  in these methods.
       Additional methods have been  developed specifically for determination of metals not covered by
       the Referenced  Methods.   These  additional  methods  contain integral  QC  required  for
       determination of metals at WQC levels.

1.5    This QC Supplement is not intended for determination of metals at concentrations normally found
       in treated and untreated discharges from industrial facilities. Existing regulations (40 CFR Parts
       400 - 500) typically limit concentrations in industrial discharges to the mid to high part-per-billion
December 1994                                                                              l

                                                                                      I           7 7

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels	


        (ppb) range, whereas ambient metals concentrations are normally in the low part-per-trillion (ppt)
        to low ppb range.

1.6   •  The ease of contaminating ambient water samples with the metal(s) of interest and interfering
        substances cannot be  overemphasized.   This QC Supplement includes  suggestions for
        improvements in facilities and analytical techniques that should maximize the ability of the
        laboratory to make reliable trace metals determinations and minimize contamination.  These
        suggestions are given in Section 4.0 "Contamination and Interferences" and are based on findings
        of researchers performing trace metals analyses (References 17.1 -  17.6).

1.7     Clean and Ultra-clean-The terms "Clean" and "Ultra-clean" have been applied to the techniques
        needed to reduce or eliminate contamination in trace metals determinations. These terms are not
        used in  this QC  Supplement because of their lack of an exact definition.   However, the
        information provided in this QC  Supplement is consistent with  and  copied  from  summary
        guidance on Clean and Ultra-clean techniques (Reference 17.7)..

1.8     This QC Supplement follows the EPA Environmental Methods Management Council's "Format
        for Method Documentation"  (Reference 17.8), and is therefore consistent with the Referenced
        Methods and the additional methods described in Section 1.4.  Where appropriate, sections of the
        Referenced Methods have been expanded  by this QC  Supplement  to  include the  increased
        operational procedures and QC necessary for determination of trace  metals at EPA WQC levels.
        In these instances, the  procedures and QC  in this QC Supplement take precedence over the
        procedures and  QC in the Referenced Methods;  otherwise,  all  procedures and QC in the
        Referenced Methods must be followed.

1.9     This QC Supplement is  "performance-based"; i.e., an alternate procedure or technique may be
        used, as long  as the performance  requirements in the Referenced Methods and this QC
        Supplement are met.  Section 9.1.2  gives details of the tests and documentation required to
        support equivalent performance.

1.10    For dissolved metal determinations, samples must be filtered through a 0.45 /*m capsule filter at
        the field site.   The filtering procedures are described in the Sampling Method.   The filtered
        samples  may  be preserved  in the field or transported to the laboratory for  preservation.
        Procedures for field preservation are detailed in the Sampling Method; procedures for laboratory
        preservation are provided in this QC  Supplement.

1.11    The procedures in this QC Supplement are for use only by personnel thoroughly trained in the
        handling and analysis of samples for determination of metals at EPA WQC levels.
2.0    SUMMARY OF QC SUPPLEMENT

2.1    Expanded  and  standardized QC—The  QC in each  Referenced  Method  is expanded and
       standardized by this QC Supplement to include:  tests of calibration linearity and calibration
       verification; demonstration of initial precision and recovery; demonstration of ongoing precision
       and recovery; analysis of matrix spike and matrix spike duplicate samples; and analysis of blanks.
       QC acceptance criteria for each test are also included in this document.  This standardized QC
       was developed in conjunction with the  development of a data review guidance document being
       generated  to  support verification  and  validation  of WQC data.  The data review guidance
                                                                                 December 1994

-------
	QC Supplement for Determination of Trace Metals at EPA WQC Levels


        document will be titled Method for Review of Trace Metals Data Generated Using EPA Metals
        Methods (hereinafter referred to as the Data Review Method).

2.2   '  Revised QC limits—QC acceptance criteria in the Referenced Methods have been revised in this
        QC Supplement to reflect measurements at low levels and to make these criteria more realistic
        than those given in the Referenced Methods. The acceptance criteria were revised using a simple
        analysis of variance (ANOVA) statistic.  The revised criteria,  which were verified in a single-
        laboratory study, are presented in Table 2.

2.3     Development of Minimum Levels (MLs)—The  ML is "the lowest  level  at which the  entire
        analytical system gives a recognizable signal and acceptable calibration point" (Reference  17.9).
        In principle, the ML is identical to the American Chemical Society (ACS) limit of quantitation
        (LOQ; Reference 17.10).  The ML is developed by multiplying the EPA 7-replicate MDL (40
        CFR  136, Appendix B) by 3.18 to achieve the ACS LOQ. The resulting exact number is then
        rounded to allow its use in instrument calibration.  Calibration at the ML is required  in every
        laboratory practicing this QC Supplement to support WQC metals measurements (Section  10.1).
        Minimum levels for the metals  are given  in  Table  1.   Laboratories making  trace metals
        measurements using the Referenced Methods  and this  QC  Supplement  must calibrate the
        instrument at the ML prior to proceeding with analysis, thus demonstrating that the ML can be
        achieved and proving that trace metals measurements can be made at the ML.
3.0    DEFINITIONS

3.1    Apparatus-Throughout  this  QC  Supplement,  the  sample  containers, sampling devices,
       instrumentation, and all other materials and devices used in sample collection, sample processing,
       and sample analysis activities will be referred to collectively as the Apparatus.

3.2    Other  definitions of terms are given in the Glossary  (Section 18) at the end of this  QC
       Supplement.
4.0    CONTAMINATION AND INTERFERENCES

4.1    Preventing ambient  water samples from becoming  contaminated during the sampling  and
       analytical process constitutes one of the greatest difficulties  encountered with  trace metals
       determinations.  Over the last two decades, marine chemists have come to recognize that much
       of the historical data regarding the concentrations of dissolved  trace metals  in seawater are
       erroneously high because the concentrations  reflect contamination from sampling and analysis
       rather than ambient levels. More recently, historical trace metals data collected from freshwater
       rivers and streams have been shown to be similarly biased due to contamination during sampling
       and analysis (Reference  17.11). Therefore, it is imperative that extreme care be taken to avoid
       contamination when collecting and analyzing ambient water samples for trace metals.

".2    There are numerous  routes by which samples may become contaminated.  Potential sources of
       trace metals contamination during sampling include: metallic or metal-containing labware (e.g.,
       talc gloves which contain high levels of zinc), containers, sampling equipment, reagents,  and
       reagent water; improperly cleaned and stored  equipment, labware, and reagents;  and atmospheric
       inputs such as dirt and dust.  Even human contact can be a source of trace metals contamination.
December 1994

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels	


        For example, it has been demonstrated that dental work (e.g. mercury amalgam fillings) in the
        mouths of laboratory personnel can contaminate samples that are directly exposed to exhalation
        (Reference 3).
      9
4.3     Contamination Control      .

        4.3.1   Philosophy—The philosophy behind contamination control is to ensure that any object or
               substance that contacts the sample is metal free and free from any material  which may
               contain metals.

               4.3.1.1        The  integrity of  the  results produced cannot be  compromised by
                              contamination of samples. Requirements and suggestions for control of
                              sample contamination are given in this  QC Supplement, the Sampling
                              Method, and the Referenced Methods.

               4.3.1.2        Substances in a sample cannot be allowed to contaminate the laboratory
                              work  area  or  instrumentation  used for trace  metals measurements.
                              Requirements and suggestions for protecting the laboratory are given in
                              this QC Supplement.

               4.3.1.3        While contamination control is  essential, personnel health  and safety
                              remain the highest priority. Requirements and suggestions for personnel
                              safety are given in Sections 5  of this QC  Supplement, the Sampling
                              Method, and the Referenced Methods.

        4.3.2   Avoiding contamination—The best way to control contamination is to completely avoid
               exposure of the sample to contamination in the first place.  Avoiding exposure means
               performing operations in an area known or thought to be free from contamination.  Two
               of the  most important factors in avoiding/reducing sample contamination are: (1) an
               awareness of potential sources of contamination and (2) strict attention to work being
               done. Therefore it is imperative that the procedures described in the Referenced Methods
               and this QC Supplement be carried out by well-trained, experienced personnel.

               4.2.3.1        Use a clean environment~The ideal environment for processing samples
                              is a  class-100 clean room  (Section  6.1.1).  If a clean  room is not
                              available, all sample preparation must be performed in a class-100 clean
                              bench or a non-metal  glove box fed  by particle-free air or nitrogen.
                              Digestions must be performed in a non-metal fume hood, ideally situated
                              in the clean room.

               4.3.2.2        Minimize exposure—The Apparatus that will contact samples, blanks, or
                              standard solutions must only be opened or exposed  in a clean room,
                              clean bench, or glove box so that exposure to an uncontrolled atmosphere
                              is minimized. When not being used, the Apparatus should  be covered
                              with  clean plastic wrap, stored in the clean bench or in a plastic box or
                              glove box,  or bagged in  clean zip-type bags. Minimizing the  time
                           .   between cleaning and use will also minimize contamination.
                                                                                 December 1994

-------
                              QC Supplement for Determination of Trace Metals at EPA WQC Levels
               4.3.2.3        Clean work surfaces-Prior to processing a given batch of samples, all
                              work surfaces in the hood, clean bench, or glove box in  which the
                              samples will be processed should be cleaned by wiping with a lint-free
                      "  •     cloth or wipe soaked with reagent water.

               4.3.2.4        Wear gloves-Sampling personnel must  wear  clean, non-talc gloves
                              (Section 6.2.4) during all operations involving handling of the Apparatus,
                              samples, and  blanks.  Only clean gloves may touch the  Apparatus.  If
                              another object or substance is touched, the glove(s) must be changed
                              before again handling the Apparatus.  If it is even suspected that gloves
                              have become contaminated, work must  be halted,  the contaminated
                              gloves removed,  and a new  pair  of clean gloves put  on.   Wearing
                              multiple layers of clean gloves will allow the old pair to be quickly
                              stripped with  minimal disruption to the work activity.

               4.3.2.5        Use metal-free Apparatus-All Apparatus used for metals determinations
                              at ambient water quality criteria levels must be non-metallic and/or free
                              of material that may contain metals.

                              4.3.2.5.1      Construction materials—Only  the following materials
                                            should come in contact with samples:   fluoropolymer
                                            (FEP, PTFE),  conventional  or linear  polyethylene,
                                            polycarbonate, polypropylene, polysulfone, or ultra-pure
                                            quartz.  PTFE is less desirable than  FEP because the
                                            sintered material in PTFE may contain contaminates and
                                            is susceptible  to  serious  memory   contamination
                                            (Reference 17.6).  Only fluoropolymer should be used
                                            for samples that will be analyzed for mercury because
                                            mercury vapors can  diffuse in  or  out of  the other
                                            materials resulting either in contamination or low-biased
                                            results (Reference  17.3).  Glass  and metal must not be
                                            used under any circumstance.  All materials regardless
                                            of construction that will directly or indirectly contact the
                                            sample must be cleaned  using the procedures described
                                            in Section 11 and must be known to be clean and metal-
                                            free before proceeding.

                              4.3.2.5.2      The following materials have been found to contain trace
                                            metals and must not be used to hold liquids that come in
                                            contact with the sample  or must not contact the sample
                                            itself, unless these materials have been shown to be free
                                            of the metals of interest at the desired level:  Pyrex,
                                            Kimax,  methacrylate,   polyvinylchloride,  nylon,  and
                                            Vycor (Reference  17.6).   In addition, highly colored
                                            plastics,  paper  cap liners,  pigments used  to mark
                                            increments on plastics, and rubber all contain trace levels
                                            of metals and must be avoided (Reference 17.10).
December 1994                                                                                5

                                                                                                      3'

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels
                             4.3.2.5.3      Serialization—Serial numbers should be indelibly marked
                                            or  etched  on  each  piece  of  Apparatus  so  that
                                            contamination can be traced,  and logbooks should be
                                            maintained to track the  sample  from the  container
                                            through the labware to injection into the instrument.  It
                                            may be useful to dedicate separate sets of labware to
                                            different  sample types;  e.g.,  receiving  waters vs.
                                            effluents.  However,  the Apparatus used for processing
                                            blanks and standards  must be mixed with the Apparatus
                                            used to process  samples so that contamination of all
                                            labware can  be detected.

                             4.3.2.5.4      The laboratory or cleaning  facility is  responsible for
                                            cleaning the Apparatus used by the sampling team. If
                                            there are any indications that the Apparatus is not clean
                                            when received by. the sampling team  (e.g., ripped
                                            storage  bags),  an  assessment  of the likelihood of
                                            contamination must  be  made.    Sampling must not
                                            proceed  if   it  is  possible   that the  Apparatus is
                                            contaminated. If the Apparatus is contaminated, it must
                                            be returned  to the laboratory or  cleaning facility for
                                            proper cleaning before any sampling activity resumes.

              4.3.2.6        Avoid Sources of Contamination-Avoid contamination by being aware
                             of potential sources and routes of contamination.

                             4.3.2.6.1      Contamination by carry-over—Contamination may occur
                                            when a  sample containing low concentrations of metals
                                            is  processed immediately after  a sample containing
                                            relatively high concentrations of these metals. To reduce
                                            carry-over,  the  sample  introduction  system  may  be
                                            rinsed between samples with  dilute  acid  and reagent
                                            water.  When an unusually  concentrated  sample is
                                            encountered,  it is followed by analysis of a laboratory
                                            blank to check for carry-over.  For samples containing
                                            high levels of metals, it may be necessary to acid clean
                                            or replace the connecting tubing or inlet system to assure
                                            that  contamination    will   not  affect   subsequent
                                            measurements.  Samples known or suspected to contain
                                            the lowest concentration of metals should be analyzed
                                            first followed by samples containing higher levels.  For
                                            instruments  containing autosamplers,  the laboratory
                                            should keep  track of which station is used for a given
                                            sample.  When  an unusually  high concentration of a
                                            metal is detected in a sample, the station used for that
                                            sample  should be cleaned more thoroughly to prevent
                                            contamination of subsequent samples, and the results for
                                            subsequent samples should be checked for evidence of
                                            the metal(s)  that occurred in  high concentration.
                                                                                  December 1994

-------
                              QC Supplement for Determination of Trace Metals at EPA WQC Levels
                              4.3.2.6.2       Contamination by samples—Significant laboratory or
                                             instrument contamination  may  result  when  untreated
                                             effluents, in-process waters, landfill leachates, and other
                                             samples  containing High  concentrations of  inorganic
                                             substances are processed and analyzed.  As stated in
                                             Section 1.0,  this  QC Supplement  is not intended for
                                             application to  these  samples, and samples  containing
                                             high  concentrations  (> ~ 10  /tg/L)   should not  be
                                             permitted into the clean room and laboratory dedicated
                                             for processing trace metals samples.

                              4.3.2.6.3       Contamination by indirect  contact—Apparatus that may
                                             not directly come  in contact with the samples may  still
                                             be a source of contamination. For example, clean tubing
                                             placed in a dirty plastic bag may pick up contamination
                                             from  the  bag  and  then  subsequently transfer  the
                                             contamination to the sample.  Therefore, it is imperative
                                             that every piece of the Apparatus that is directly or
                                             indirectly used in the collection, processing, and analysis
                                             of ambient water samples be cleaned  as specified in
                                             Section 11.

                              4.3.2.6.4       Contamination  by airborne  paniculate matter—Less
                                            obvious substances capable of contaminating samples
                                             include  airborne  particles.     Samples    may   be
                                            contaminated by airborne dust, dirt, particles, or vapors
                                            from: unfiltered air supplies; nearby corroded or rusted
                                            pipes, wires, or other fixtures; metal-containing paint;
                                            and  even human  breath  (Section  4.2).   Whenever
                                            possible, sample processing and analysis should occur as
                                            far as possible from sources of airborne contamination.
4.4    Interferences
       4.4.1   Section  4 of  each of the Referenced  Methods describes the types and  nature of
               interferences that may be encountered.  However, as the concentration of the metal(s)
               being determined decreases,  the  effects of interferences  increase.  Therefore, more
               extensive  sample  preparation steps,  such  as  chelation/extraction or  ion  exchange
               chromatography, may be necessary to separate the analyte of interest from interferences
               when determining metals at the levels for which this QC Supplement is intended.

       4.4.2   Interferences  resulting  from  samples  will  vary  considerably  from source to source,
               depending on  the  diversity of the site  being sampled.  If a sample is suspected of
               containing substances that may interfere in the determination of trace metals, sufficient
               sample should be collected to  allow the laboratory to identify and overcome interference
               problems.
December 1994

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels    	


5.0     SAFETY

        The toxicity or carcinogenicity of the  chemicals used in this QC Supplement has not been
      -  precisely determined; however, these chemicals should be treated as a potential health hazard.
        Exposure should be reduced to the lowest possible level.  Laboratories are responsible for
        maintaining a current awareness file of OSHA regulations regarding the safe handling of the
        chemicals specified in this QC Supplement.  A  reference file of Material Safety  Data Sheets
        should also be made available to all personnel involved in sample handling and analysis.
6.0     APPARATUS AND EQUIPMENT

        Disclaimer:  The mention of trade names or commercial products in this QC Supplement is for
        illustrative purposes only and does not constitute endorsement or recommendation for use by the
        Environmental Protection Agency.  Equivalent performance may be achievable using apparatus
        and materials other than those suggested here. Demonstration of equivalent performance is the
        responsibility of the laboratory.

6.1     Facility

        6.1.1   Clean room-class-100, 200 ft2 minimum, with down-flow, positive-pressure ventilation,
               air-lock entrances, and pass-through doors.

               6.1.1.1        Construction materials-non-metallic, preferably plastic sheeting attached
                             without metal fasteners.   If painted, paints that do  not contain the
                             metal(s) of interest must be used.

               6.1.1.2        Adhesive mats, for use at entry points  to  control dust and dirt from
                             shoes.

        6.1.2   Fume hoods, non-metallic, two minimum, with one installed internal to the clean room.

        6.1.3   Clean benches, class-100, one installed  in the clean room; the other adjacent to the
               analytical instruments) for preparation of samples and standards.

6.2     Labware—All labware must be metal' free.  Suitable construction  material are fluoropolymer
        (FEP, PTFE), conventional or linear  polyethylene, polycarbonate, or polypropylene. Only
        fluoropolymer should be used when mercury is a target analyte.  All labware should be cleaned
        per the procedure below (Section  11.4). Gloves, plastic wrap, storage bags, and filters may all
        be used new without additional cleaning unless results of the equipment blank pinpoint any of
        these materials as a source of contamination. In this case, either an alternate supplier must be
        obtained or the materials must be cleaned.

        6.2.1   Beakers-50, 100, and 500 mL

        6.2.2   Pipets-1.0, 10, and 100 mL

        6.2.3   Tongs-For removal of Apparatus from acid baths. Coated metal tongs may not be used.
8                                                                                December 1994

-------
	QC Supplement for Determination of Trace Metals at EPA WQC Levels


        6.2.4   Gloves-clean, non-talc polyethylene, latex, or vinyl; various lengths.  Heavy gloves
               should be worn when working in acid baths since baths will contain hot, strong acids.

        6.2.5   Buckets or basins—5 - 50 liter capacity,  for acid soaking of the Apparatus.

        6.2.6   Non-metallic brushes for scrubbing Apparatus

        6.2.7   Storage bags—clean,  zip-type, non-vented,  colorless polyethylene (various sizes) for
               storage of Apparatus

        6.2.8   Plastic wrap-clean, colorless polyethylene for storage of Apparatus

6.3     Sampling Equipment—The laboratory or cleaning facility is responsible for cleaning, storing, and
        shipping all sampling devices, sample bottles, filtration equipment, and all other Apparatus used
        for the collection of ambient water samples. Prior to shipping the equipment to the field site, the
        laboratory or facility must generate an acceptable equipment  blank (Section 9.5.3) in order to
        demonstrate that the sampling equipment is free from contamination.

        6.3.1   Sampling Devices-Prior to the collection of ambient water samples, consideration should
               be given to the type of sample to be collected and the devices to be used (grab, surface,
               or subsurface samplers).  The laboratory or cleaning facility must clean all devices used
               for sample collection. Various types of samplers are described in the Sampling Method.
               Cleaned sampling devices should be stored in polyethylene bags or wrap.

        6.3.2   Sample bottles—Fluoropolymer (FEP,  PTFE),  conventional  or linear polyethylene,
               polycarbonate, or polypropylene; 500 mL with lids.  Cleaned sample bottles should be
               filled  widi 0.1%  HC1 (v/v) until use.   Note:  If mercury is a  target analyte,  then
               fluoropolymer bottles must be used.

        6.3.3   Filtration Apparatus

               6.3.3.1        Filters, Gelman Supor 0.45 /xm, 15 mm diameter filter capsules (Gelman
                              12175), or equivalent

               6.3.3.2       Battery-powered peristaltic pump

               6.3.3.3       Pump tubing


6.4     Alkaline detergent-Liquinox®, Alconox®, or equivalent

6.5     pH meter or pH paper
7.0    REAGENTS AND STANDARDS

       Each reagent lot shall be tested for the metals of interest by diluting and analyzing an aliquot
       from the lot using the techniques and instrumentation to be used for analysis of samples. The
December 1994

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels     	


       lot will be  acceptable if the concentration of the metal of interest is below the MDL of the
       Referenced  Method or the Additional Method being used.

7.1  ' Reagents for cleaning Apparatus, sample bottle storage, and sample preservation.

       7.1.1   Nitric acid (HNO3): Concentrated, Seastar, or equivalent
                                     y
       7.1.2   Nitric acid (HNO3): Dilute (1 + 1), Seastar, or equivalent

       7.1.3   Nitric acid (HNO3): 10% wt, Seastar, or equivalent

       7.1.4   Hydrochloric acid (HC1): 6N trace metal grade  ,

       7.1.5   Hydrochloric acid (HC1):  IN trace metal grade

       7.1.6   Hydrochloric acid (HC1):  10% wt, trace metal grade

       7.1.7   Hydrochloric acid (HC1):  1 % wt, trace metal grade

       7.1.8   Hydrochloric acid (HC1): 0.5%  (v/v), trace metal grade (each lot must be pre-analyzed
               before use to ensure the acid is free from mercury contamination.)

       7.1.9   Hydrochloric acid (HCI): 0.1 %  (v/v) ultrapure grade

7.2    Reagent water-water demonstrated to  be free from the metal(s) of interest and potentially
       interfering substances at the MDL for that metal in the Referenced Method or Additional Method.
       Prepared by distillation, deionization, reverse osmosis, anodic/cathodic stripping voltammetry,
       or other technique that removes the metal(s) and potential interferent(s).


8.0    SAMPLE COLLECTION, FILTRATION, PRESERVATION, AND  STORAGE

8.1    Sample collection—Samples are collected as described in the Sampling Method.

8.2    Sample filtration—For dissolved metals, samples and field blanks are filtered through a 0.45 /im
       capsule filter at the field site.  Filtering procedures are described in the Sampling Method.

8.3    Sample preservation—Preservation of samples may be performed in the field or in the laboratory.
       Field preservation is necessary for determinations of trivalent chromium.  It has also been shown
       that field preservation with sodium hydroxide can increase sample holding times for hexavalent
       chromium to 30 days; therefore it  is  recommended that preservation  of samples for hexavalent
       chromium be performed in the field as described in Method 1669.  For other metals, however,
       the sampling team may prefer to utilize laboratory preservation of samples in order to expedite
       field operations and to minimize the potential for sample contamination. Samples and field blanks
       should be preserved at the laboratory immediately upon receipt. For all metals except mercury,
       preservation involves the addition of 10% HNO3 (Section 7.1.3) to bring the sample to pH <2.
       For samples received at neutral pH, approx 5 mL of 10% HNO3 per liter will be required. For
       mercury, 0.5% (v/v) HCI (Section 7.1.8) is used as the preservative.
 10                                                                              December 1994

-------
              	QC Supplement for Determination of Trace Metals at EPA WQC Levels


        8.3.1   Wearing clean gloves, remove the cap from the sample bottle, add the volume of reagent
               grade acid that will bring the pH to < 2, and re-cap the bottle immediately.  If the bottle
               is full, withdraw the necessary volume using a pre-cleaned pipet and then add the acid.
               Record the volume withdrawn and the amount of acid used.

               Note:  Do not dip pH paper or a pH meter into the sample; remove a small aliquot with
               a clean pipet and test the aliquot.

        8.3.2   Store the preserved sample for a minimum of 48 hours at 0 - 4 °C to  allow the acid to
               completely dissolve the metal(s) adsorbed on the container walls.

        8.3.3   With each sample set, preserve a method blank and an OPR sample in the same way as
               the sample(s).

        8.3.4   Sample bottles should be stored in polyethylene bags at 0 - 4  °C until analysis.


9.0     QUALITY ASSURANCE/QUALITY CONTROL

9.1     Each laboratory that uses this QC Supplement is required to operate a formal quality assurance
        program (Reference 17.13).  The  minimum requirements of this  program consist of an initial
        demonstration of laboratory capability, analysis  of samples spiked with metals  of interest to
        evaluate and document data quality,  and  analysis of standards and blanks as tests of continued
        performance.  Laboratory performance  is  compared to established performance  criteria to
        determine if the results of analyses meet the performance characteristics of the method.

        9.1.1   The  analyst shall  make  an initial demonstration of the ability  to  generate  acceptable
               accuracy and precision with this method.  This ability is established as described in
               Section 9.2.

        9.1.2   In recognition of  advances that are occurring in analytical technology, the analyst is
               permitted to exercise certain options to  eliminate interferences or lower the costs of
               measurements.  These options include alternate digestion, concentration, and cleanup
               procedures, and changes  in instrumentation. Alternate determinative techniques, such as
               the substitution of a colorimetric technique or changes that degrade method performance,
               are not allowed.  If an analytical technique other than the techniques specified in the
               Referenced Method is used, then that technique must have a specificity equal to or better
               than  the specificity of the techniques in Referenced Method for the analytes of interest.

               9.1.2.1       Each time a modification is made to a Referenced Method, the analyst
                             is required  to repeat  the procedure in Section 9.2.  If the detection limit
                             of the method will be affected by the change,  the laboratory is required
                             to demonstrate that the MDL (40 CFR Part 136, Appendix B) is lower
                             than the MDL for the Referenced Method or one-third of the regulatory
                             compliance level, whichever is higher. If calibration will be affected by
                             the change, the analyst must recalibrate the instrument per Section 9 of
                             the Referenced  Method.
December 1994                                                                                11

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels
               9.1.2.2        The laboratory is required to maintain records of modifications made to
                              this QC Supplement or the Referenced Methods.  These records include
                              the following, at a minimum:

                              9.1.2.2.1      The names, titles, addresses, and telephone numbers of
                                            the  analyst(s)  who  performed  the  analyses  and
                                            modification,  and of  the  quality control  officer who
                                            witnessed and will verify the analyses and modification.

                              9.1.2.2.2      A  listing  of metals  measured,  by  name and  CAS
                                            Registry number.

                              9.1.2.2.3      A narrative stating reason(s) for the modification(s).

                              9.1.2.2.4      Results from all quality control (QC) tests comparing the
                                            modified method to. the Referenced Method, including:

                                            a)      Calibration
                                            b)      Calibration verification
                                            c)      Initial precision and recovery (Section 9.2 of this
                                                    QC Supplement).
                                            d)      Analysis of blanks
                                            e)      Accuracy assessment

                              9.1.2.2.5      Data that will allow an independent reviewer to validate
                                            each  determination  by tracing  the instrument output
                                            (peak height,  area, or other signal) to the final result.
                                            These data are to include, where possible:

                                            a)      Sample  numbers and other identifiers.
                                            b)      Digestion/preparation or extraction dates.
                                            c)      Analysis dates and times.
                                            d)      Analysis sequence/run chronology.
                                            e)      Sample  weight or volume.
                                            f)      Volume prior  to each  extraction/concentration
                                                    step.
                                            g)      Volume after each extraction/concentration step.
                                            h)      Final volume prior to analysis.
                                            i)      Injection volume.
                                            j)      Dilution data, differentiating between dilution of
                                                    a sample or extract.
                                            k)     Instrument and  operating conditions  (make,
                                                    model, revision, modifications).
                                            1)      Sample   introduction    system   (ultrasonic
                                                    nebulizer,  hydride  generator, flow  injection
                                                    system, etc).
                                            m)     Operating   conditions  (ashing   temperature,
                                                    temperature program, flow rates, etc).
                                            n)     Detector (type, operating conditions, etc).
12                                                                                 December 1994

-------
	  QC Supplement for Determination of Trace Metals at EPA WQC Levels


                                             o)     Mass spectra, printer tapes, and other recordings
                                                    of raw data.
                                             p)     Quantitation reports, data system outputs, and
                                                    other data to  link the raw data to  the  results
                                                    reported.

        9.1.3  Analyses  of blanks are  required to demonstrate freedom from contamination.   The
               required types, procedures, and criteria for analysis of blanks are described in Section
               9.5.

        9.1.4  The laboratory shall spike at least 10% of the samples with the metal(s) of interest to
               monitor method performance.  This test is described in the Referenced Methods and in
               Section 9.3 of this QC  Supplement.  When  results  of these spikes indicate atypical
               method performance for samples, an alternative extraction or cleanup technique must be
               used to bring method performance within acceptable limits. If method performance for
               spikes cannot be brought within the limits given in .this QC Supplement, the result may
               not be reported for regulatory compliance purposes.

        9.1.5  The laboratory shall, on  an ongoing basis,  demonstrate through calibration verification
               and through analysis of the ongoing precision and recovery aliquot that the analytical
               system is  in  control. These procedures  are described in  Section 9 of the Referenced
               Methods and Sections 10.2 and 9.6 of this QC Supplement.

        9.1.6  The laboratory shall maintain  records to define the quality of data that are generated.
               Development of accuracy statements  is  described in Section 9.3.4.

9.2     Initial demonstration of laboratory capability

9.2.1   Method detection  limit-To establish the ability to the trace metals of interest, the analyst shall
        determine the MDL for each analyte per the procedure in 40  CFR 136,  Appendix B using  the
        apparatus, reagents, and standards the will be used in the practice of this QC Supplement and  the
        Referenced  Method.   The laboratory must produce an  MDL that is no more than 1/10  the
        regulatory compliance level or that is less than the MDL listed in Table 1, whichever is greater.

9.2.2   Initial precision and recovery (IPR)—To establish the ability to  generate acceptable precision and
       ' recovery, the analyst shall perform the following operations.

        9.2.2.1        Analyze four aliquots of reagent water  spiked with the metal(s) of interest at 2 -
                      3  times the Minimum Level (Table  1), according to the procedures in  the
                      Referenced Method. All digestion, extraction, and concentration steps, and the
                      containers, labware, and reagents that will be  used with samples, must be used
                      in this test.

        9.2.2.2       Using results of the set of four analyses,  compute the average percent recovery
                      (X) for the metal(s) in each aliquot and  the standard deviation of the recovery (s)
                      for each metal.

        9.2.2.3       For each  metal,  compare s and X with the  corresponding  limits for initial
                      precision  and recovery  in Table 2.  If s and X for  all metal (s) meet  the
December 1994                                                                                13

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels	


                       acceptance criteria, system performance is acceptable and analysis of blanks and
                       samples may begin.  If, however, any individual s exceeds the precision limit or
                       any individual X falls outside  the range for accuracy,  system performance is
                       unacceptable for that metal.  Correct the problem and repeat the test (Section
                       9.2.2.1).

9.3     Method accuracy—To assess the performance  of the method on  a given  sample matrix, the
        laboratory must perform matrix spike (MS) and matrix spike duplicate (MSD) sample analyses
        on 10% of the samples from each site being monitored, or at least one matrix spike sample
        analysis and one matrix spike duplicate sample  analysis must be performed  for each sample set
        (samples collected from the same site at the same time, to a maximum of 10 samples), whichever
        is'more frequent.                                                        ,

        9.3.1   The concentration of the MS and MSD  is determined as follows:

               9.3.1.1        If,  as in compliance monitoring, the- concentration of a specific metal  in
                              the sample is being checked against a regulatory concentration limit, the
                              spike must be at that.limit or at 5 times the background concentration,
                              whichever is greater.

               9.3.1.2        If the concentration is not being checked against a regulatory limit, the
                              concentration must be at 5 times the background concentration or at 5
                              times the ML in Table 1, whichever is greater.

        9.3.2   Assessing spike recovery

               9.3.2.1        Determine the background concentration (B) of each metal by analyzing
                              one sample aliquot  according  to the procedures specified  in the
                              Referenced Method.

               9.3.2.2        If necessary, prepare a QC check sample concentrate mat will produce
                              the appropriate level (Section 9.3.1) in the sample when the concentrate
                              is added.

               9.3.2.3        Spike a second sample aliquot with the QC check sample concentrate and
                              analyze it to determine the concentration after spiking (A) of each metal.

               9.3.2.4        Calculate each percent  recovery (P)  as 100(A-B)/T,  where T is the
                              known true value of the spike.

        9.3.3   Compare the percent recovery (P) for each metal with the corresponding QC acceptance
               criteria found in Table 2.  If any individual P falls outside the designated  range for
               recovery, that metal has failed the acceptance criteria.

               9.3.3.1        For a metal that has failed the acceptance criteria, analyze the ongoing
                              precision and recovery standard (Section 9.6). If the OPR is within its
                              respective limit for the metal(s) that failed (Table 2), the  analytical
                              system is in control and the problem is attributable to the sample matrix.
14                                                                                December 1994

-------
	QC Supplement for Determination of Trace Metals at EPA WQC Levels


               9.3.3.2         For samples that exhibit matrix problems, further isolate the metal(s)
                              from  the sample  matrix using chelation,  extraction,  concentration,
                              hydride generation, or other means, and repeat the accuracy test (Section
                              9.3.2).

               9.3.3.3         If the recovery for the metal remains outside the acceptance criteria, the
                              analytical result for that metal in the unspiked sample is suspect and may
                              not be reported for regulatory compliance purposes.

       9.3.4   Recovery for samples should be assessed and records maintained.

               9.3.4.1         After the analysis  of five samples of a given matrix type (river water,
                              lake water, etc.) for which the  metal(s) pass the tests in Section 9.3.3,
                              compute the average percent recovery (R) and the standard deviation of
                              the percent recovery (SR) for the  metal(s).   Express  the  accuracy
                              assessment as a percent recovery interval from R - 2SR to R + 2SR for
                              each matrix.  For example,  if R = 90%  and SR  =  10%  for five
                              analyses of river water, the accuracy interval is expressed as 70 - 110%.

               9.3.4.2         Update  the  accuracy assessment for each metal in each matrix on a
                              regular basis (e.g., after each five to ten new measurements).

9.4    Precision of matrix spike duplicates

       9.4.1   Calculate the relative percent  difference (RPD) between the MS and  MSD per the
               equation below  using the concentrations found  in the MS and MSD. Do not use the
               recoveries calculated in Section 9.3.2.4 for this calculation because the RPD of recoveries
               is inflated when the background concentration is near the spike concentration.


                                    RPD = ioo
                                                (D1+D2)I2
               where:
               Dl = concentration of the analyte in the MS sample
               D2 = concentration of the analyte in the MSD sample

       9.4.2   The relative percent difference between the matrix spike and the matrix spike duplicate
               must meet the acceptance criteria in the Referenced Method, or must be less  than 20
               percent if a criterion for duplicates is not given in the Referenced Method. If the criteria
               are not met, the analytical system is be judged to be out of control. In this case, correct
               the problem and reanalyze all samples in the sample set associated with the MS/MSD
               which failed the RPD test.

9.5    Blanks-Blanks are analyzed to demonstrate freedom from contamination.

       9.5.1   Laboratory (method) blank
December 1994                                                                                15

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels
               9.5.1.1        Prepare a method blank with each sample batch (samples of the same
                              matrix started through the extraction process on the same 12-hour shift,
                              to a maximum of 10 samples).  Analyze the blank immediately after
                              analysis  of the  OPR  (Section 9.6) to  demonstrate  freedom from
                              contamination.

               9.5.1.2        If the metal of interest or any potentially interfering substance is found
                              hi the blank at a concentration equal to or greater than the MDL (Table
                              1), then sample analysis must be halted, the source of the contamination
                              determined, the problem  corrected,  and the sample batch and fresh
                              method blank reanalyzed.

               9.5.1.3        Alternatively, if a sufficient number of blanks (3 minimum) are analyzed
                              to characterize the nature of a blank, the average concentration plus two
                              standard deviations must be less than the regulatory compliance level.
                                                                                        /
               9.5.1.4        If the result for a single blank remains above the MDL or if the result
                              for the average concentration plus two standard deviations  of three or
                              more blanks exceeds the regulatory compliance level, results for samples
                              associated  with  those blanks  may  not be  reported for regulatory
                              compliance purposes. Stated another way, results for all initial precision
                              and recovery tests (Section 9.2) and all samples must be associated with
                              an uncontaminated method blank before these results may be reported for
                              regulatory compliance purposes.

       9.5.2   Field blank

               9.5.2.1        Analyze the field blank(s) shipped with  each set of samples  (samples
                              collected from the same site at the same time, to a maximum of  10
                              samples).   Analyze  the blank  immediately  prior  to analysis of  the
                              samples in the batch.                                              .

               9.5.2.2        If the metal of interest or any potentially interfering substance is found
                              in the field blank at a concentration equal to or greater than the MDL
                              (Table 1), or greater than  one-fifth the level in the associated sample,
                              whichever is  greater, then results for associated samples may be  the
                              result of  contamination and  may  not  be  reported for  regulatory
                        .   .   compliance purposes.

               9.5.2.3        Alternatively, if a sufficient number of field  blanks (3 minimum)  are
                              analyzed  to characterize the nature  of  the  field blank, the average
                              concentration plus two standard deviations  must  be  less than  the
                              regulatory  compliance level  or less  than  one-half the level  in  the
                              associated sample, whichever is  greater.

               9.5.2.4        If contamination of the field blanks and associated samples is known or
                              suspected, the laboratory should communicate this to the sampling team
                              so that the .source of contamination  can be  identified and corrective
                              measures taken prior to the next sampling event.
16                                                            -                   December 1994

-------
                              QC Supplement for Determination of Trace Metals at EPA WQC Levels


        9.5.3   Equipment Blanks—Prior to the use of any sampling equipment at a given site, the
               laboratory or cleaning facility  is required  to  generate equipment blanks  in order to
               demonstrate that the sampling equipment is free from contamination.  Two types of
               equipment blanks are required:  bottle blanks and sampler check blanks.

               9.5.3.1         Bottle blanks—After undergoing appropriate cleaning procedures (Section
                              11.4), bottles should be subjected to  conditions of use to verify the
                              effectiveness of the cleaning procedures.  A representative set of sample
                              bottles  should  be filled with  reagent water  acidified to  pH<2 and
                              allowed to stand for  a minimum of 24 hours.  Ideally, the time that the
                              bottles are allowed to stand  should be as close as possible to the actual
                              time that sample will be in contact with the bottle.  After standing, the
                              water should be analyzed for any signs of contamination. If any bottle
                              shows signs of contamination, the problem  must be  identified, the
                              cleaning procedures  corrected  or cleaning solutions changed, and all
                              affected bottles recleaned.

               9.5.3.2         Sampler check  blanks-Sampler check blanks  are  generated  in the
                              laboratory or  at the  equipment  cleaning   contractor's  facility  by
                              processing reagent water through the sampling devices using the  same
                              procedures that are used in the field (see Sampling Method).   Therefore,
                              the "clean hands/dirty hands" technique utilized during field sampling
                              should  be followed  when  preparing  sampler  check blanks  at the
                              laboratory or cleaning facility.

                              9.5.3.2.1       Sampler check  blanks are generated by filling a  large
                                            carboy or other container with reagent water (Section
                                            7.2)  and  processing the  reagent water through the
                                            equipment using the same procedures that are used in the
                                            field  (see Sampling Method). For example, manual grab
                                            sampler  check  blanks   are  collected  by  directly
                                            submerging  a sample bottle into the water, filling the
                                            bottle, and capping.  Subsurface sampler check blanks
                                            are collected by immersing the sampler into the water
                                            and pumping water  into  a sample container.   "Clean
                                            hands/dirty hands" techniques must be used.

                              9.5.3.2.2       The  sampler check blank must be analyzed using the
                                            procedures  given in  the QC  Supplement and the
                                            Referenced Methods.  If any  metal of interest or any
                                            potentially interfering substance is detected in the blank,
                                            the  source  of  contamination/interference must  be
                                            identified, and  the problem corrected.  The equipment
                                            must be demonstrated to be free from the  metal(s) of
                                            interest before the equipment may be used in the field.

                              9.5.3.2.3       Sampler check blanks must be  run on all equipment that
                                            will be used  in the field. If, for example, samples are to
                                            be collected using both a grab sampling device and a
December 1994                                                                                77

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels
                                            subsurface sampling device, then a sampler check blank
                                            must be run on both pieces of equipment.
9.6  • Ongoing precision and recovery
       9.6.1   Prepare a precision and recovery sample (laboratory fortified method blank) identical to
               the initial precision and recovery aliquots (Section 9.2) with each sample batch (samples
               of the same matrix started through the extraction process on the same 12-hour shift, to
               a maximum of 10 samples) by spiking an aliquot of reagent water with the metal(s) of
               interest.

       9.6.2   Analyze the OPR aliquot prior to analysis  of the method blank and samples.from the
               same batch.

       9.6.3   Compute the percent recovery of each metal in the  OPR aliquot using the procedure
               given in the Referenced Method.

       9.6.4   For each metal, compare the concentration to the limits for ongoing recovery in Table
               2.   If all metals meet the acceptance criteria,  system performance is  acceptable and
               analysis of blanks and samples may proceed. If, however, any individual recovery falls
               outside of the range given, the analytical processes are not being performed properly for
               that metal.  In this event, correct the problem, re-prepare, extract, and clean up  the
               sample batch and repeat the ongoing precision and recovery  test (Section 9.6).

       9.6.S   Add results that pass  the specifications in Section 9.6.4 to initial and previous ongoing
               data for each metal in each matrix.  Update QC charts to form a graphic representation
               of continued laboratory performance. Develop a statement of laboratory accuracy  for
               each metal in each matrix type by calculating the average percent recovery (R) and the
               standard deviation of percent recovery (SR). Express the accuracy as a recovery interval
               from R - 2SR to R + 2SR. For example, if R =  95% and  SR = 5%, the accuracy is
               85 to 105%.

9.7    The specifications contained in this QC Supplement can be met if the instrument used is calibrated
       properly and then maintained in  a calibrated state. A given instrument will provide the most
       reproducible results if dedicated to the settings and conditions  required for the analyses of metals
       by the Referenced Method and this QC Supplement.

9.8  .  Depending on specific program requirements, field duplicates may be collected to determine the
       precision of the sampling technique.  The relative percent difference  (RPD) between field
       duplicates should be less than 20%.
 10.0    CALIBRATION AND CALIBRATION VERIFICATION

 10.1    Calibration—Calibrate the instrument as given in the Referenced Method. Calibrate at a minimum
        of three points, one of which must be the Minimum Level (Table 1), and another which must be
        near the upper end of the calibration range.  Calibration is required before any samples or blanks
        are  analyzed.
                                                                                 December 1994

-------
                             QC Supplement for Determination of Trace Metals at EPA WQC Levels
        10. 1 . 1  Internal standard calibration

               10.1.1.1       Calculate the relative response factor (RRF) for each metal in each CAL
                             solution using the equation below and the height or area of the internal
                             standard. The RRF is unitless, but units used to express quantities of the
                             metals and internal standard must be identical.
                      where:
                      Rx  = height or area of the signal for the metal
                      Ris = height or area of the signal for the internal standard.
                      Cx  = concentration of compound injected G*g/L)
                      Cis = concentration of internal standard injected (/ig/L)

               10.1.1.2       For each metal, calculate the mean RRF (M), the standard deviation of
                             the RRF (SD), and  the relative standard deviation (RSD) from each
                             mean, where RSD = 100 x SD/M.

               10.1.1.3       Linearity - If the RSD of the mean RRF for any metal is less than 15
                             percent over the calibration range, an averaged relative response factor
                             may be  used for that analyte.  Otherwise, a calibration curve for that
                             metal must be  used over the calibration range.

       10.1.2  External standard calibration

               10.1.2.1       Calculate the response factor (RF) for each metal in each CAL solution
                             using the equation below and the height or area produced by the metal.
               where:
               Rx  = height or area of the signal for the metal
               Cx  = concentration of compound injected Qig/L)

               10. 1 .2.2       For each metal, calculate the mean RF (M), the standard deviation of the
                             RF (SD), and the relative standard deviation (RSD) of the mean, where
                             RSD = 100 x SD/M.

               10.1.2.3       Linearity - If the RSD of the mean RF for any metal is less than 25
                             percent over the calibration range, an averaged response factor may be
                             used for that analyte. Otherwise, a calibration curve for that metal must
                             be used over the calibration range.
December 1994                                                                                79

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels	


        10.1.3 Acceptable calibration curves for both internal and external standard calibration are first
               order (linear  with non-zero intercept) for  GFAA,  and first order  or second order
               (quadratic  with a square term and  with  or  without  a zero  intercept) for other
               instrumentation.  Third order (cubic term) curves, spline fits, and other irregular curves
               are not representative of calibration data and may not be used.

10.2    Calibration verification—Immediately following calibration,  an initial  calibration  verification
        should be performed.  Adjustment of the instrument is performed until verification criteria are
        met.  Only after these criteria are met may blanks and samples be analyzed.

        10.2.1  Verify the specificity of the instrument for each metal and adjust the wavelength or
               tuning until the resolving power specified in the Referenced Method is met.

        10.2.2 Inject the mid-point calibration standard (Section  10.1) or laboratory performance check
               solution specified in the Referenced Method.

        10.2.3 Compute the percent recovery of each metal using the mean response or calibration curve
               obtained in the initial calibration.

        10.2.4 For each  metal,  compare the  recovery with the  corresponding  limit  for calibration
               verification in Table 2.  If all metals meet the acceptance criteria,  system performance
               is acceptable and analysis of blanks and samples  may continue using the response from
               the initial calibration.   If any  individual value falls outside the  range given,  system
               performance is unacceptable  for that compound.  In this event, locate and  correct the
               problem and/or prepare a new calibration check standard and repeat  the test (Section
               10.2.2 - 10.2.4), or recalibrate the system per the Referenced Method and Section 10.1.

        10.2.5  Calibration should be verified following every ten samples by analyzing the mid-point
               calibration standard. If the recovery does not meet the acceptance criteria specified in
               Table 2, analysis must be halted, the problem corrected, and the instrument recalibrated.
               All samples after the last acceptable calibration verification must be reanalyzed.


11.0    CLEANING THE APPARATUS

11.1    All sampling equipment,  sample containers,  and  lab ware should be cleaned in a designated
        cleaning area that has  been demonstrated to be free of trace element contaminants.  Such areas
        may include class. 100 clean rooms as. described by Moody (Reference 17.14),  labware cleaning
        areas as described by  Patterson  and Settle (Reference 17.6), or clean benches.

11.2    Materials, such as gloves (Section 6.2.4), storage bags (Section 6.2.7), and plastic wrap (Section
        6.2.8), may be used new  without additional cleaning unless the results of the equipment blank
        pinpoint any of these  materials  as a  source of contamination.  In this case, either an alternate
        supplier must be obtained  or the materials must be cleaned.

11.3    For new Apparatus and Apparatus known or suspected to be contaminated, initial cleaning outside
        of the clean room using detergent and concentrated, technical grades of acid is a prudent means
        of reducing the initial contamination and ensuring that contamination is not brought into the clean
        facility.
20                                                                                December 1994

-------
 	QC Supplement for Determination of Trace Metals at EPA WQC Levels


 11.4   Cleaning procedure

        11.4.1 Bottles, labware, and sampling equipment
      »

               11.4.1.1       Fill a pre-cleaned basin (Section 6.2.5) with a sufficient quantity of a
                              0.5% solution of liquid detergent (Section 6.4), and completely immerse
                              each piece of ware.  Allow to soak in the detergent for at least 30
                              minutes.

               11.4.1.2       Using a pair of clean gloves (Section 6.2.4)  and  clean  non-metallic
                              brushes (Section 6.2.6), thoroughly scrub down all materials with the
                              detergent.

               11.4.1.3       Place the scrubbed materials in a pre-cleaned basin.  Change gloves.

               11.4.1.4       Thoroughly rinse the inside and outside of each piece with reagent water
                              until there  is no sign of detergent residue (e.g., until all soap bubbles
                              disappear).

               11.4.1.5       Change gloves, immerse the rinsed equipment in a hot (50-60 °C) bath
                              of concentrated reagent grade HNO3 (Section 7.1.1) and allow to soak
                              for at least two hours.

               11.4.1.6       After soaking, use clean gloves and tongs to remove the Apparatus and
                              thoroughly rinse widi distilled, deionized water (Section 7.2).

               11.4.1.7       Change gloves, immerse all equipment in a hot (50-60  °C) bath of IN
                              trace metal grade HC1 (Section 7.1.5), and allow to soak for at least 48
                              hours.

               11.4.1.8       Thoroughly rinse all equipment and bottles with reagent water. Proceed
                              with Section 11.4.2 for labware and sampling equipment. Proceed with
                              Section 11.4.3 for sample bottles.

        11.4.2 Labware and sampling equipment

               11.4.2.1        After cleaning, air dry in a class 100 clean air bench.

               11.4.2.2       After  drying, wrap each piece of  ware/equipment in two layers  of
                              polyethylene film.

        11.4.3 Fluoropolymer sample  bottles—These bottles should  be used if mercury  is a target
               analyte.

               11.4.3.1       After cleaning, fill sample bottles with 0.1 % (v/v) ultrapure HC1 (Section
                              7.1.9) and  cap tightly. It may  be necessary to use  a strap wrench  to
                              assure a tight seal.
December 1994                                                                                 21

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels	


               11.4.3.2       After capping, double bag  each bottle in polyethylene zip-type bags.
                              Store at room temperature until sample collection.

     * 11.4.4 Bottles, labware, and  sampling equipment (polyethylene or other material  besides
              fluoropolymer)

               11.4.4.1       Apply the steps outlined above in Section 11.4.1.1  - 11.4.1.8 to all
                              bottles, labware,  and sampling equipment.   Proceed  with  Section
                              11.4.4.2  for  bottles  or  Section 11.4.4.3 for labware and sampling
                              equipment.

               11.4.4.2       After cleaning, fill bottles with 0.1 % (v/v) ultrapure HC1 (Section 7.1.9).
                              Double bag each bottle in a polyethylene bag to prevent contamination
                              of the surfaces  with  dust and  dirt.   Store at room temperature until
                              sample  collection.

               \ 1.4.4.3       After rinsing  labware and sampling equipment,  air dry in a class 100
                              clean air bench.  After drying, wrap  each piece of ware/equipment in
                              two layers of polyethylene film.

              NOTE:         Polyethylene  bottles cannot  be used to collect  samples  that  will be
                              analyzed  for  mercury at trace  (e.g., 0.012 /ig/L)  levels due to the
                              potential of vapors diffusing through the polyethylene.

               11.4.4.4       Polyethylene bags-if polyethylene bags need to be cleaned,  clean per the
                              following procedure:

                              11.4.4.4.1     Partially  fill with cold, (1 + 1) HNO3 (Section 7.1.2) and
                          x                 rinse with distilled deionized water (Section 7.2).

                              11.4.4.4.2     Dry by hanging upside down from a plastic line with a
                                            plastic clip.

11.4.6 Silicone  tubing, fluoropolymer tubing, and  other  sampling apparatus-Clean  any silicone,
       fluoropolymer, or other tubing used to collect samples by rinsing with  10% HC1 (Section 7.1.6)
       and flushing with water from the site  before sample collection.

11.4.7 Extension pole—Due to its  length, it is impractical to submerse the two-meter  polyethylene
       extension pole (used in with the  optional grab sampling device) in acid solutions as described
       above.  If such an extension pole is used, a non-metallic brush (Section 6.2.6) should be used to
       scrub the pole with reagent water and the pole wiped down with acids described in Section 11.4.4
       above.  After cleaning, the pole should  be wrapped in polyethylene film.

11.5   Storage—Store each  piece or assembly of the  Apparatus in a clean, single polyethylene zip-type
       bag.  If shipment is  required, place the bagged apparatus in a second polyethylene zip-type bag.

11.6   All cleaning solutions and acid baths should be periodically monitored for accumulation of metals
       which could lead to  contamination. When levels of metals in  the solutions become too high, the
22                                                                                December 1994

-------
                             QC Supplement for Determination of Trace Metals at EPA WQC Levels
        solutions and baths should be changed and the old solutions discarded in compliance with state
        and federal regulations.
 12.0   SAMPLE ANALYSIS

 12.1   For trivalent chromium,  analyze the samples by graphite furnace atomic absorption (GFAA)
       spectroscopy using EPA Method 200.9 and the QC Supplement.  Do not perform the sample
       preparation procedures listed in Section 11 of EPA Method 200.9 for trivalent chromium.  The
       method of standard additions may be necessary if matrix interferences are present.

 12.2   For all other analytes, detailed procedures for sample processing and analysis are given in each
       of the Referenced Methods.
13.0   DATA ANALYSIS AND CALCULATIONS

13.1   Compute the concentration of each metal in /ig/L (parts-per-billion; ppb) using the calibration
       data.

13.2   If the concentration of the metal exceeds the calibration range of the instrument, dilute the sample
       by successive factors of 10 until the concentration is within the calibration range.

13.3   Report results at or above the ML for metals found in samples  and determined in standards.
       Report all results for metals found in blanks, regardless of level.

13.4   Report results to one significant figure at or below the MDL, two significant figures between the
       MDL and ML, and three significant figures at or above the ML.

13.5   Do not perform blank subtraction on the sample results.
14.0   METHOD PERFORMANCE

       Performance data are given in the Referenced Methods.


15.0   POLLUTION PREVENTION

15.1   The acids used  in this method should be reused as practicable by purifying by electrochemical
       techniques. The only other chemicals used in this method are the neat materials used in preparing
       standards.  These standards are used in extremely small amounts and pose little threat to the
       environment when managed properly.

15.2   Standards should be prepared in volumes consistent with laboratory use to minimize the volume
       of expired standards to be disposed.
December 1994                                                                              23

                                                                                                    :, 1

-------
QC Supplement for Determination of Trace Metals at EPA WQC Levels
16.0   WASTE MANAGEMENT

16.1   It is the  laboratory's responsibility to comply with all federal, state, and local  regulations
     -  governing  waste management, particularly the  discharge  regulations,  hazardous waste
       identification rules, and land disposal restrictions; and to protect the air, water, and  land by
       minimizing and controlling all releases from fume hoods and bench operations.

16.2   Samples preserved with acid to pH <2 are hazardous and must be neutralized before being
       poured down a drain or must be handled as hazardous waste.

16.3   For further information on waste management, consult "The Waste Management Manual for
       Laboratory Personnel"  and  "Less  is Better-Laboratory  Chemical Management  for Waste
       Reduction,"  available from  the American Chemical  Society's Department of Government
       Relations and Science Policy, 1155 16th Street N.W., Washington, D.C. 20036.
17.0   REFERENCES

17.1   Adeloju, S.B.; Bond, A.M. Anal. Chem. 1985, 57, 1728. "Influence of Laboratory Environment
       on the Precision and Accuracy of Trace Element Analysis."

17.2   Berman, S.S.; Yeats, P.A. CRC Reviews in Analytical Chemistry 1985, 16, 1. "Sampling of
       Sea water for Trace Metals."

17.3   Bloom, N.S. Presented at the 16th Annual EPA Conference on the Analysis of Pollutants in the
       Environment, Norfolk, Virginia, May 5, 1993. "Ultra-Clean Sampling, Storage, and Analytical
       Strategies for the Accurate Determination of Trace Metals in Natural Waters."

17.4   Bruland, K.W. Chemical Oceanography 1983, 8, 157. "Trace Elements in Seawater."

17.5   Nriagu, J.O.; Larson, G.; Wong, H.K.T.; Azcue, J.M. J. Great Lakes Research 1993,19,  175.
       "A Protocol for  Minimizing Contamination in the  Analysis of Trace Metals in Great Lakes
       Waters."

17.6   Patterson, C.C.; Settle, D.M. In National Bureau of Standards Special Publication 422; LaFleur,
       P.O., Ed., U.S.  Government Printing Office,  Washington,  DC,  1976.  "Accuracy  in Trace
       Analysis."

17.7   Prothro, Martha G., "Office of Water Policy and  Technical Guidance on  Interpretation and
       Implementation of  Aquatic Life Metals Criteria", EPA Memorandum  to Regional  Water
       Management and Environmental Services Division Directors, October 1, 1993.

17.8   "Format for Method  Documentation", Distributed by the EPA  Environmental Monitoring
       Management Council, Washington, DC, November  18, 1993.

17.9   Methods 1624 and 1625, 40 CFR Part 136,  Appendix A.

17.10  Anal. Chem. 1983, 14, 2210.
 24                                                                            December 1994

-------
                   	QC Supplement for Determination of Trace Metals at EPA WQC Levels


17.11  Windom, H.L; Byrd, J.T.; Smith, R.G., Jr.; Huan, F. Environ. Sci. Technol. 1991, 25, 1137.
       "Inadequacy of NASQAN Data for Assessing Metal Trends in the Nation's Rivers."

17.12' Zief, M.; Mitchell, J.W. in Chemical Analysis; 1976; Vol. 47 "Contamination Control in Trace
       Metals Analysis;" Chapter 6.

17.13  Handbook  of Analytical Quality  Control  in  Water  and  Wastewater  Laboratories;  U.S.
       Environmental Protection Agency. EMSL-Cincinnati, OH, March 1979; EPA-600/4-79-019.

17.14  Moody, J.R. Anal.  Chem.  1982,  54,  1358A.  "NBS  Clean Laboratories for Trace  Element
       Analysis."


18.0   Glossary of Definitions and Purposes

       These definitions and purposes are specific to this QC Supplement but have been conformed to
       common usage as much as possible.

18.1   Analyte - A metal tested for by the methods referenced in this QC Supplement.  The analytes
       are listed in Table  1.

18.2   Apparatus — The sample container and other containers, filters, filter holders, labware, tubing,
       pipets, and other materials and devices used for sample collection or sample preparation, and that
       will contact samples, blanks, or analytical standards.

18.3   Calibration standard  (CAL) —  A solution prepared from a dilute mixed standard and/or stock
       solutions and  used  to  calibrate the response of the  instrument with  respect  to analyte
       concentration.

18.4   Equipment blank — An aliquot of reagent water that is subjected in the laboratory to all aspects
       of sample collection and analysis, including contact with all sampling devices and apparatus. The
       purpose of the equipment blank is determine if the sampling devices and apparatus for sample
       collection have been adequately cleaned  prior to  shipment to the  field site.  An acceptable
       equipment blank must be achieved before the sampling devices and apparatus are used for sample
       collection.  In addition, equipment blanks should be run on random, representative sets of gloves,
       storage bags,  and  plastic wrap  for each  lot to determine if these materials are  free from
       contamination prior to use.

18.5   Field blank — An aliquot of reagent water that is placed in a sample container in the laboratory,
       shipped to the field, and treated as a sample in all respects, including contact with the sampling
       devices and exposure  to sampling site conditions,  storage, preservation, and  all analytical
       procedures, which may include filtration.  The purpose of the field blank is to determine if the
       field or sample transporting procedures and environments have contaminated the sample.

18.6   Field duplicates  (FD1 and FD2) - Two separate samples collected in separate sample bottles at
       the same time and  place under identical circumstances and treated exactly the same throughout
       field and laboratory  procedures.  Analyses of FD1 and FD2 give a measure of the precision
       associated  with sample  collection, preservation, and storage, as well  as with  laboratory
       procedures.
December 1994                                                                               25

-------
          QC Supplement for Determination of Trace Metals at EPA WQC Levels	'


          18.7    Initial precision and recovery (IPR) — Four aliquots of the ongoing precision and recovery
                  standard analyzed to establish the ability to generate acceptable precision and accuracy. EPRs are
                  performed prior to the first time a method is used and any time the method or instrumentation
                '  is modified.   . .

          18.8    Laboratory blank — An aliquot of reagent water that is treated exactly as a sample including
                  exposure to all glassware, equipment, solvents, reagents, internal standards, and surrogates that
                  are used with samples.  The laboratory blank is used to determine if analytes or interferences
                  are present in the laboratory environment, the reagents, or the apparatus.

          18.9    Laboratory control  sample (LCS) - See Ongoing precision and recovery standard (OPR).

          18.10   Laboratory duplicates (LD1 and LD2) — Two aliquots of the same sample taken in the laboratory
                  from the same sample bottle and analyzed separately using the referenced method. Analyses of
                  LD1  and LD2 indicate precision  associated  with  laboratory procedures, but not with  sample
                  collection, preservation, transportation, or storage  procedures.

          18.11   Laboratory fortified blank — See Ongoing precision and recovery standard (OPR).

          18.12   Laboratory fortified sample matrix — See Matrix spike and matrix spike duplicate.

          18.13   Laboratory reagent blank — See Laboratory blank.

          18.14   Matrix spike (MS) and matrix spike duplicate (MSD) — Aliquots of an environmental sample to
                  which known quantities of the analytes are added in the  laboratory.  The MS and MSD are
                  analyzed exactly like a sample. Their purpose is to quantify the bias and precision caused by the
                  sample  matrix.   The background concentrations of the analytes in the sample matrix must be
                  determined in  a separate aliquot and the measured values in the MS  and MSD corrected  for
                  background concentrations.

          18.15   May  — This action, activity, or procedural  step is neither required nor prohibited.

          18.16   May  not — This action, activity, or procedural step is prohibited.

          18.17   Method blank - See Laboratory blank.

          18.18   Minimum  level  (ML) —  The  lowest level  at which the entire  analytical system gives a
                  recognizable signal and acceptable calibration point (Reference 9).

          18.19   Must - This action, activity, or procedural step is required.

          18.20  Ongoing precision and recovery standard - A laboratory blank spiked with known quantities of
                  analytes.   The OPR is analyzed exactly like a sample.  Its purpose is to assure that the results
                  produced by the laboratory remain  within the limits specified  in the Referenced Methods  for
                  precision and accuracy:

          18.21  Preparation blank — See Laboratory blank.
           26                                                                               December 1994
.?

-------
	QC Supplement for Determination of Trace Metals at EPA WQC Levels


18.22   Primary dilution standard — A solution containing the analytes that is purchased or prepared from
        stock solutions and diluted as needed to prepare calibration solutions and other solutions.

18.23'  Quality control  sample (QCS) — A sample containing all or a subset of the analytes at known
        concentrations.  The QCS is obtained from a source external to the laboratory or is prepared from
        a source of standards different  from the source of calibration standards.  It is used to check
        laboratory performance with test materials prepared external to the normal preparation process.

18.24   Reagent water—water demonstrated to  be free from  the  metal(s) of interest and potentially
        interfering substances at the MDL for that metal in the Referenced Method or Additional Method.

18.25   Should —  This  action, activity,  or procedural step is suggested but not required.

18.26   Stock  solution — A solution containing an analyte that is prepared using a reference material
        traceable to EPA, the National Institute of Science and Technology (NIST), or a source that will
        attest to  the purity and authenticity of the reference material.
December 1994                                                                                 27

-------
                                                       Table 1
 Lowest EPA Water Quality Criteria for Toxic Metals and Species; Existing EPA Methods that Achieve or
    Come Closest to Achieving these Criteria; and Analytical Techniques, Minimum Levels, and Method
                                     Detection Limits for these EPA Methods
Key:
Notes:
1.
2.
3.
4.
Metal
Antimony
Arsenic
Cadmium
Chromium (in)
Chromium (VI)
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Lowest EPA
Water
• Quality
Criterion
(r&LY
14
0.018
0.32
57
10.5
2.5
0.14
0.012
7.1
5
0.31
1.7
28
EPAMeth
Method
200.8
200.9
—
200.8
200.9
200.10
200.13
—
218.6
200.8'
200.10
200.8
200.10
200713
—
200.8
200.9
200.10
200.8
200.9
200.8
200.8
200.8
200.9
trd wialytV ftf tarhnifni
«/L
Technique
ICP/MS
STGFAA
—
ICP/MS
STGFAA
CC/ICP/MS
CC/STGFAA
• —
Ion Chrom.
ICP/MS
CC/ICP/MS
ICP/MS
CC/ICP/MS
CC/STGFAA
—
ICP/MS
STGFAA
CC/ICP/MS
ICP/MS
STGFAA
ICP/MS
ICP/MS
ICP/MS
STGFAA
IB, and MDL/ML in
MDL1
0.007
0.34
—
0.025
0.013
0.00094
0.0029
. —
0.23
0.043
0.0083
0.015
0.0039
0.012
—
0.33
0.65
0.013
1.2
0.69
0.018
0.007
0.069
0.10
ML*
0.02
1
—
0.1
0.05
0.002
0.01
—
0.5
0.1
0.02
0.05
0.01
0.05
—
1
2
0.05
5
2
0.05
0.02
0.2
0.2
WQClerd
achiered?1
Yes
Yes
No
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
ICP      =  Inductively coupled plasma                      Ion chrom
AES     =  Atomic emission spectrometry                   CC
MS      =  Mas* spectrometry                             CVAF
GFAA   =  Graphite furnace atomic abiorption spectrometry    STGFAA
Ion chromatography
etiolation/concentration
Cold vapor atomic fluorescence
Stabilized temperature GFAA
Lowest of the freshwater, marine, and human health WQC promulgated by EPA for 14 states at 40 CFR Part 131 (57 FR 60848),
with hardness-dependent freshwater aquatic life criteria adjusted in accordance with 57 FR 60848 to reflect the worst case hardness
of 25 mg/L CaCO, and all aquatic life criteria adjusted in accordance with the 10/1/93 Office of Water guidance to reflect dissolved
metals criteria. A complete listing of all WQC, including total, dissolved, and levels calculated with a hardness of 25 mg/L CaCQ
and a hardness of 100 mg/L CtCO, is provided in Appendix A.

Determination of the metal is achieved if MDL it less than one-tenth the WQC level.

Method Detection Limit as determined by 40 CFR Part 136, Appendix B.

Minimum Level (ML) calculated by multiplying laboratory-determined MDL by 3.18 and rounding result to nearest multiple of 1,
2, 5, 10, 20, 50 etc. in accordance with procedures utilized by EAD and described in the EPA Draft .National Guidance for the
Permitting, Monitoring, and Enforcement of Water Quality-Based Effluent Limitations Set Below Analytical Detection/Quantitation
Levels, March 22,  1994.
 28
                                                                                                      December 1994

-------
                     	  QC Supplement for Determination of Trace Metals at EPA WQC Levels


                                                   Table 2

                      Quality Control Acceptance Criteria for Performance Tests1
Method
200.8
200.9



200.10



200.13

218.6
Metal
Antimony
Cadmium
Copper
Lead
Nickel
Selenium
Silver
Thallium
Zinc
Antimony
Cadmium
Nickel
Selenium
Zinc
Cadmium
Copper
Nickel
Lead
Cadmium
Lead
Chromium (IV)
Initial Precision and
Recovery (Section 93)
6 X
20 81-120
13 85-112
43 55-141
30 75-140
30 71-131
41 63-145
19 82-120
30 66-134
43 55-142
60 24-144
11 67-142
36 69-141
31 60-128
19 67-142
23 75-121
41 56-139
27 74-128
44 56-144
23 70-116
27 63-117
20 80 - 120
Calibration Verification
(Section 10.2)
90-111
91-105
76-120
91-120
86-116
83-125
91-111
82-118
76-121
54-114
86-123
87-123
77-111
86-123
86-1 10
77-119
87-115
78-122
81-105
77-103
90-110
Ongoing Precision and
Recovery (Section 9.6)
79-122
84-113
51-145
72-143
68-134
59-149
81-121
64-137
46-146
18-150
64-145
65-145
56-131
67-142
73-123
53-142
71-130
52-144
70-116
60-120
79-122
, Spike Recovery
(Section 9.3)
79-122
84-113
51-145
72-143
68-134
59-149
81-1212
64-137
46-146
18-150
64-145
65-145
56-131
67-142
73-123
53-142
71-130
52-1442
70-116
60-1202
79-122
1.        All specification expressed as percent.

2.        Based on preliminary laboratory data, spike recovery specifications for silver by Method 200.8 and lead by Methods 200.10 and
         200.13 may need to be revised. Additional spike recovery data is pending.
December 1994
                                                                                                          29

-------
                   SECTION 4

  Guidance on the Documentation and Evaluation of
          Trace Metals Data Collected for
           CWA Compliance Monitoring

EPA Office of Water, Engineering & Analysis Division

-------
Guidance on the Documentation and Evaluation of
         Trace Metals Data Collected for
     Clean Water Act Compliance Monitoring
                       Draft
                   December 1994
          U.S. Environmental Protection Agency
                   Office of Water
            Office of Science and Technology
         Engineering and Analysis Division (4303)
                    401 M  St. SW
                Washington, DC 20460

-------
Acknowledgements

This guidance was prepared under the direction of William A. Telliard of the Engineering and Analysis
Division (HAD) within the U.S. Environmental Protection Agency's (EPA) Office of Science  and
Technology  (OST).   This guidance was  prepared under EPA Contract 68-C3-0037 by  DynCorp
Environmental, with the assistance of Interface, Inc.
Disclaimer

This document has been reviewed and approved for publication by the Analytical Methods Staff within
the Engineering and Analysis Division of the EPA Office of Water.   Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.
Further  Information

For further information, contact:

       William A. Telliard, Chief .
       Analytical Methods Staff
       Engineering and Analysis Division
       U.S. Environmental Protection Agency
       401 M Street
       Washington, DC 20460
       Phone: 202-260-7134
       Fax:   202-260-7185

-------
                                                                                   Chapter 1

                                                                                    Introduction

        Numerous organizations, such as state pollution control agencies, health departments, local
 government agencies, industrial dischargers, research facilities, and federal agencies (e.g., EPA, USGS),
 collect data on effluent and ambient metal concentrations for use in a variety of applications, including:
 determining attainment status for water quality standards, discerning trends in water quality, estimating
 effluent  concentrations and variability, estimating  background loads for total maximum daily loads
 (TMDLs),  assessing permit compliance, and  conducting research1.   The quality of data used is an
 important issue,  and, in particular, the quality of trace level metals data may be compromised  due to
 contamination during sampling, filtration, storage, and analysis. In fact, one of the greatest obstacles
 faced by laboratories attempting trace metals determinations is the potential for contamination of samples
 during the sampling and analytical processes.  Trace metals are ubiquitous in the  environment, and
 samples can readily become contaminated by numerous sources,  including:  metallic or metal-containing
 labware, metal-containing reagents,  or metallic  sampling equipment; improperly cleaned and  stored
 equipment;  and atmospheric inputs such  as dirt, dust, or  other particulates from exhaust or corroded
 structures.

        The measurement of trace metals  at ambient EPA water quality criteria (WQC) levels has been
 spurred by the increased emphasis  on a water quality-based approach to  the control of toxic pollutants.
 Current ambient WQC levels2 for trace metals require measurement capabilities at levels as  much  as 280
 times lower than  those levels required to support technology-based controls or achievable by routine
 analyses in environmental laboratories. The findings in the USGS and EPA studies strongly indicate that
 rigorous steps must be taken in order to preclude contamination in future gathering of trace metals data.

        In order to ensure that the data collected for trace metals determinations at ambient water quality
 criteria levels are valid and not a result of contamination, rigorous quality control (QC) must be applied
 to all sample collection, preparation, and analysis activities.  EPA has published analytical methods (1983,
 1991)  for monitoring  metals in waters and wastewaters, but  these methods are inadequate for the
 determination of ambient concentrations of metals in ambient waters due to the lack of some or all of the
 essential quality control criteria.  This has prompted the Engineering and  Analysis Division (BAD) to
develop  a draft  document  for sampling, entitled Method 1669:   Sampling  Ambient Water for
Determination of Trace Metals at EPA Water Quality Criteria Levels (Method 1669), and a draft quality
 control supplement to  existing  EPA  metals  methods   entitled,  Quality Control  Supplement for
Determination of Trace Metals at EPA Water Quality Criteria Levels Using EPA Metals Methods (QC
 Supplement),  that include the rigorous sample handling and quality control procedures necessary to
 deliver verifiable data at WQC levels.
   '     Prothro, M., Acting Assistant Administrator for Water, Memorandum to Water Management Division Directors and
        Environmental Services Division Directors, Oct. 1, 1993.

   2     "Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants; States' Compliance" (also
        referred to as "The National Toxics Rule"). 40 CFR Part 131, (57 FR 60848, December 22, 1992).
December 1994

-------
Data Evaluation Guidance
        Appropriate quality assurance (QA) and quality control (QC). procedures are the key to producing
precise and accurate data unbiased by contamination.  Examination of trace metals data without data from
blanks and other QC analyses yields little or no information on whether sample data are reliable. Data
quality must be documented through the use  of blanks (both field and laboratory blanks), standards,
matrix spike/matrix spike duplicates, and field duplicates, as well as other QC analyses. The results of
all QC procedures must be included in the data reporting package along with the sample results if data
quality is to be known.

       The remainder of this document  contains guidance that is intended to aid  in the review of trace
metals data submitted  for compliance  monitoring purposes under the National Pollutant Discharge
Elimination System (NPDES) when these data were collected in accordance  with Method 1669, the QC
Supplement, and the methods referenced in the QC Supplement. Chapter 2 of this document outlines the
data elements that must be reported  by laboratories and permittees so that EPA reviewers can validate
the data.  Chapter 3 provides guidance concerning the review of data"collected and reported in accordance
with Chapter 2.  Chapter 4 provides  a Data Inspection  Checklist that can  be used to  standardize
procedures for documenting the findings of each data inspection.

       The guidance provided in these chapters is similar in principle to the data reporting and review
guidance provided  in  EPA's  Guidance  on Evaluation,  Resolution, and Documentation of Analytical
Problems Associated with Compliance Monitoring (EPA 821-B-93-001), but has been specifically adapted
to reflect particular concerns related  to the evaluation of data for trace metals.
                                                                                  December 1994

-------
                                                                               Chapter 2

                                                   Checklist of Laboratory Data Required
                                     to  Support Compliance Monitoring for Trace Metals
                                       Determined in Accordance with Method 1669, the
                                            QC Supplement, and the Referenced Methods
       The items listed below describe the minimum data elements necessary to validate trace metals data
collected using the Method for Sampling Ambient Water for Determination of Trace Metals at EPA Water
Quality Criteria Levels (Method 1669) and the Quality Control Supplement for Determination of Trace
Metals at EPA Water Quality Criteria Levels Using EPA Metals Methods (QC Supplement) in conjunction
with EPA metals methods.  It should be noted that since different instrumentation yields different data
output, the specific form of the data will vary according to the analytical method.

1.     Method Number

       The method number of the base EPA metals method used in conjunction with Method 1669 and
the QC Supplement must be provided. This information will allow a data reviewer to become familiar
with the method, if necessary,  prior to reviewing the data. It will also assist the reviewer in making any
necessary determinations of the comparability of these data with previously reported data.  If more than
one method is needed  to cover a complement of analytes, then all method numbers must be provided.
A clear delineation of the specific method used for each given analyte is required.  Also, the revision date
or revision level and number/letter of the  method must be given, so that the reviewer tests the results
submitted against the specific method used.  A list of the metals and metal species that  have published
WQC levels and the corresponding EPA method(s) is provided in Table 1.

       In recognition of advances that are occurring in analytical technology,  the QC Supplement is
performance-based.  That is, an  alternate procedure or technique may be used if the performance
requirements in the reference method(s) and QC Supplement are met.  The analyst must start with one
of the methods as a reference, and may improve upon this reference method to reduce interferences or
lower costs of  measurements.  Examples include using alternate chelating or ion exchange  resins,
alternate  matrix modifiers, additional cleanup techniques, or more sensitive detectors.  The objective of
allowing  method modifications is to improve method performance on the sample  being analyzed. At no
time are changes that degrade method performance allowed. Section 9.1.2 of the QC Supplement gives
details of the tests and documentation required to support equivalent performance.
2.     Detailed Narrative

       A detailed narrative discussing any problems with the analysis, corrective actions taken,  and
changes made to the reference method must be included in a complete data reporting package. Reasons
for changes to the reference method, supporting logic behind the technical approach to the change, and
the result of the change must be included in the narrative.  The narrative should be written by an
analytical chemist in terms that another analytical chemist can understand.
December 1994

-------
             Data Evaluation Guidance
             3.   .  Summary Level Report or Data Report Forms

                    The complete data reporting package must include a summary level report or data reporting forms
             that list all samples analyzed, the metals and metal species determined, and the concentrations found.
             Analytes detected in field samples at concentrations below the minimum level (ML) must be reported as
             non-detect.  However, all analyte concentrations detected in blank samples must be reported, regardless
             of the level.  Results must be listed for each sample analyzed,  including any dilutions and reanalyses.
             Metals should be listed by name and CAS Registry number.

                    The ML is the  quantitation level as defined by the QC Supplement  and the reference  EPA
             method.  The laboratory is required to determine the MDL for each  analyte  in accordance with  the
             procedures described in  40 CFR Part 136, Appendix B- Definition and  Procedure for Determination of
             Method Detection Limit - Revision 1.11.  That MDL multiplied by 3.18 must be less than or equal to  the
             ML given in the Table 1 of the QC Supplement.

             4.     Summary of Quality Control Results

                    Results for all  quality control  analyses required by  the reference  EPA method  and the QC
             Supplement must be presented in the complete data reporting package. Certain expanded QC procedures
             in the QC Supplement take precedence over the corresponding QC procedures in the reference methods.
             It must be clearly evident which QC corresponds to a given method and" set of samples if more than one
             base method was used or if more than one set of samples was analyzed.

                    Results for QC procedures  that must be provided include, but are not limited  to, the following
             (where applicable):

             •      Instrument tuning
             •  .    Calibration
             •      Calibration verification (initial and following every 10 analytical samples)
             •      Initial precision and recovery
             •      Ongoing precision and recovery
             •      Blanks
                            Laboratory (method) blanks
                            Field blanks
                            Calibration blanks
                            Equipment blanks
             •      Matrix spike/matrix spike duplicates
             •      Field duplicates
             •      Method of standard additions (MSA) results
             •      Spectral interference checks
             •      Serial dilutions
             •      Internal standard recoveries
             •      Method detection limits
             •      Quality control charts and limits

             Table 2 lists the required frequency and purpose of the QC procedures.


             4                                                                               December 1994
//y

-------
                                                                         Data Evaluation Guidance
5.   •  Raw Data  . .

        Raw data and  other  information that will allow  an independent reviewer to- validate  each
determination and calculation performed by the laboratory must be included in the data reporting package.
The instrument output (emission intensity, peak height, area, or other signal intensity) must be traceable
from the raw data to the final  result reported.  The raw data must be provided for not only the analysis
of each field sample but also  for all calibrations, verifications,  blanks, matrix spike/matrix spike
duplicates, field duplicates, and other QC analyses required by the base method and QC Supplement.

        Raw data are method and instrument specific and may  include, but are not limited to, the
following:

•       Sample numbers and other identifiers
•       Digestion/preparation or extraction dates
•       Analysis dates and times
•       Analysis sequence/run chronology
•       Sample weight or volume
•       Volume prior to each extraction/concentration step
•       Volume after each extraction/concentration step
•       Final volume prior to analysis
•       Injection volume
•       Matrix modifiers
•       Dilution data, differentiating between dilution of a sample or an extract
•       Instrument (make, model, revision, modifications)
•       Sample introduction system (ultrasonic nebulizer, hydride generator, flow injection system, etc.)
•       Column (manufacturer, length, diameter, chelating or ion exchange resin, etc.)
•       Operating conditions (char/ashing temperatures,  temperature program,  incident rf power, flow
        rates, plasma viewing height, etc.)
•    '   Detector (type, wavelength, slit, analytical mass monitored, etc.)
•       Background correction scheme
•       Quantitation reports, data  system outputs, and other.data to link the  raw data to the results
        reported
•       Direct instrument readouts (e.g.,  strip charts, mass spectra, printer tapes, and other recordings
        of raw data) and other data to support the final results
•       Lab bench sheets and copies of all pertinent  logbook pages for all  field and  QC sample
        preparation and  cleanup steps, and for all other parts of the determinations
6.      Example Calculations

        Example calculations that will allow an independent reviewer to determine how the laboratory
used the raw data to arrive at a final result must be provided in the data reporting package.   Useful
examples include both detected and undetected compounds.  If the laboratory or the method employs a
standardized reporting level for undetected compounds,  this should be made clear in the example
December 1994

-------
Data Evaluation Guidance
calculation.  Adjustments made for sample volume, dilution,  internal standardization, etc. should be
evident.              "   •
7.      Magnetic Media

        It is not necessary for the laboratory or responsible organization to submit digitized binary,
hexadecimal,  or other raw signal recordings with the data package.  However, the laboratory that
performs the analysis should archive these data so that the raw reduced data can be reconstructed, and
the laboratory or organization responsible for reporting the data should be prepared to submit raw data
on magnetic media, upon request by EPA.  Magnetic media may be required for automated data review,
for diagnosis of data reduction problems, or for establishment of an analytical database.
8.      Names, Titles, Addresses, and Telephone Numbers of Analysts and QC Officer

        The  names,  titles,  addresses,  and telephone numbers of the analysts  who performed the
determinations and the quality control  officer who verified the results must be  included in the data
reporting package.  If the data package is being submitted by a person or organization other than the
analytical laboratory,  it is that person or organization's responsibility to ensure that  the laboratory
provides all the data listed above and that  all method requirements are met. For example, with regards
to effluent or ambient monitoring data  submitted by an NPDES permittee on a Discharge Monitoring
Report (DMR), the task of collecting and  reporting quality control data falls to the permittee.

     .   In addition, the personnel, titles, addresses, telephone numbers, and name  (if different from the
laboratory that analyzed the field samples) of the facility that cleaned and shipped the sampling equipment
and generated the equipment blanks, the laboratory (if different) that analyzed the equipment blanks, and
the facility responsible for the collection,  filtration, and transport of the field samples to the laboratory
must be obtained and included in the data  reporting package.
                                                                                  December 1994

-------
                                                       Table 1

   Analytes Amenable to Collection and Determination Using the Sampling Method,  the QC Supplement,
   and the Base Methods;  Lowest Ambient Water Quality Criterion for Each Metal or Metal Species; and
      Method Numbers, Analytical Techniques, Method Detection Limits, and Minimum Levels for the
                                              Applicable EPA Methods
Key:
Notes:
1.
2.

3.

4.
Metal
Antimony
Arsenic
Cadmium
Chromium (III)
Chromium (VI)
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Lowest EPA'
Water
Quality
Criterion
G»g/L)'
14
0.018
0.32
57
10.5
2.5
0.14


0.012
7.1


5

0.31
1.7
28

EPA Method, analytical technique, and MDL/ML in
Mg/L
Method
200.8
200.9
—
200.8
200.9
200.10
200.13
—
218.6
200.8
200.10
200.8
200.10
200.13
—
200.8
200.9
200.10
200.8
200.9
200.8
200.8
200.8
200.9
Technique
ICP/MS
STGFAA
...
ICP/MS
STGFAA
CC/ICP/MS
CC/STGFAA
'
Ion Chrom.
ICP/MS
CC/ICP/MS
ICP/MS
CC/ICP/MS
CC/STGFAA
...
ICP/MS
STGFAA
CC/ICP/MS
ICP/MS
STGFAA
ICP/MS
ICP/MS
ICP/MS
STGFAA
MDLJ
0.007
0.34
...
0.025
0.013
0.00094
0.0029
_.
0.23
0.043
0.0083
0.015
0.0039
0.012
...
0.33
0.65
0.013
1.2
0.69
0.018
0.007
0.069
0.10
ML4
0.02
1
_.
0.1
0.05
0.002
0.01

0.5
0.1
0.02
0.05
0.01
0.05
...
1
2
0.05
5
2
0.05
0.02
0.2
0.2
WQC level
achieved?1
Yes
Yes
No
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
ICP      =  Inductively coupled plasma                      Ion chrom
AES     =  Atomic emission spectrometry             '       CC
MS      =  Mass spectrometry                             CVAF
GFAA   =  Graphite furnace atomic absorption spectrometry     STGFAA
Ion chromatography
Chelation/concentration
Cold vapor atomic fluorescence
Stabilized temperature GFAA
Lowest of the freshwater, marine, and human health WQC promulgated by EPA for 14 states at 40 CFR Part 131 (57 FR 60848),
with hardness-dependent freshwater aquatic life criteria adjusted in accordance with 57 FR 60848 to reflect the worst case hardness
of 25 mg/L CaCOj and all aquatic life criteria adjusted in accordance with the 10/1/93 Office of Water guidance to reflect dissolved
metals criteria.  A complete listing of all WQC, including total, dissolved, and levels calculated with a hardness of 25 mg/L CaCO,
and a hardness of 100 mg/L CaCO, is provided in Appendix A.

Determination of the metal is achieved if MDL is less than one-tenth the WQC level.

Method Detection Limit as determined by 40 CFR Part 136, Appendix B.

Minimum Level (ML) calculated by multiplying laboratory-determined MDL by 3.18 and rounding result to nearest multiple of 1,
2, 5, 10, 20, 50 etc. in accordance with procedures utilized by EAD and described in the  EPA Draft National Guidance for the
Permitting, Monitoring, and Enforcement of Water Quality-Based Effluent Limitations Set Below Analytical Detection/Quantitation
Levels, March 22, 1994.

-------
X
\
                                         Table 2 - Quality Control Requirements, Frequency, and Purpose
Required QC Test
• Instrument tuning
Calibration (CAL)
Calibration verification (VER)
Initial precision and recovery
(IPR)
Method detection limit (MDL)
and minimum level (ML)
Ongoing precision and recovery
(OPR)
Blanks
Matrix spike/matrix spike
duplicate (MS/MSD)
Field duplicate
Method of standard addition
(MSA)
Internal standardization
Spectral interference check
Serial dilutions
Frequency
Prior to calibration
Prior to sample analysis and whenever calibration cannot be verified
Immediately prior to and following the analysis of every batch of 10 or
fewer analytical samples analyzed at the same time ,
Prior to using the method for the first time and each time a modification to
the method is made
Prior to using the method and whenever there is change that will affect the
MDL and ML
Each sample batch (Sample batch size is method specific. Where hot
specified, batch size is 10.)
Equipment blank-Prior to use of any sampling equipment at a given site
Calibration blank-Immediately following each calibration verification
Laboratory (method) blank (BLK)-One method blank per sample batch
Field blank (FBK)--Every ten samples collected at a given site or at least
one per sample site, whichever is more frequent
Each batch of 10 or fewer samples from the same site
Each batch of 10 or fewer samples from the same site
As needed to assure the reliability of results for GFAA or ICP analyses
All analyses by ICP/MS (EPA Methods 200.8 and 200.10)
Prior to using the method for the first time and periodically thereafter as
indicated by instrument stability, type of samples analyzed, and expected
interferences encountered
When analyte concentration is sufficiently high (minimally a factor of 10X
the MDL after dilution)
Purpose
To assure that the instrument will produce results equivalent to instruments
in other laboratories
To establish the working range of the analytical instrument
To verify the average response or curve from the initial calibration
To establish the ability of the laboratory to generate acceptable precision and
recovery
To determine the lowest level at which the analyte can be detected with 99%
confidence that the concentration is greater than zero
To assure that the laboratory remains in control
To assure that contamination of sampling devices and apparatus for sample
collection will be detected prior to shipment to the field site
To assure that contamination of the analytical system will be detected, if
present
To assure that contamination of the analytical process will be detected, if
present
Tp assure that contamination of field samples will be detected, if present
' To determine bias caused by sample matrix effects
To measure the precision associated with sample collection, preservation,
transportation', and storage procedures, as well as with analytical procedures
To compensate for a sample constituent that enhances or depresses the
analyte signal
To correct instrument drift and other variations in the analytical process
To establish corrections for known interelement spectral interferences
To determine if a chemical or physical interference effect is present
1

-------
                                                                                Chapter  3

                                                              Guidance for Reviewing Data
                                                 from the Analysis of Trace Metals Using
                        Method 1669, the QC Supplement, and the Referenced Methods


        The use of guidelines provided below, or of similarly developed standardized protocols, is highly
recommended as a tool with  which Regional and  State permitting authorities can standardize  data
inspection and acceptance procedures and minimize differences that might otherwise result between data
reviewers and/or permittees responsible for submitting data.  A Data Inspection Checklist has also been
developed and is provided in the following chapter.  This checklist provides a standardized format for
documenting the findings of each data inspection and an additional tool for standardizing the data review
process within a regulatory agency.

1.      Purity and Traceability of Reference Standards/

        The accuracy of any non-absolute empirical measurement is dependent on the reference for that
measurement. In determining pollutants in water or other sample matrices, the analytical instrument and
analytical process  must  be  calibrated with a  known  reference  material.   Method 1669,  the  QC
Supplement, and referenced methods all require that the standards used for calibration and other purposes
be of known purity and traceable to a reliable reference source.

        Documentation of the purity and traceability of the standards need not  be provided with every
sample analysis. Rather, it should be maintained on file at the laboratory and provided  upon request.
When analyses  are conducted in a contract laboratory, such documentation should be provided to the
permittee the first time that the laboratory is employed for specific analyses and updated as needed.

2.      Number of Calibration Points

        The QC Supplement specifies that a minimum of three concentrations are to be used when
calibrating  the instrument. (Some  of the referenced methods require the use of additional calibration
points.)  One of these points must be the Minimum Level (ML, see item 5), and another must be near
the upper end of the calibration range. Calibration must be performed for each target metal before any
samples or blanks are  analyzed. The use of the ML as a point on the calibration curve is the principal
means by which to assure that measurements made at this quantitation level are reliable.

        The data reviewer should review the points used by the laboratory to calibrate the instrument and
make certain that the  calibration range encompasses the Minimum Level and that all sample and QC
measurements are within the calibration range.  Samples that produce results that exceed the calibration
range should have been diluted and reanalyzed, in accordance with Section 13.2 of the QC Supplement.
The diluted sample results need only  apply to those analytes that exceeded the  calibration range of the
instrument.  In other words, it is acceptable to use data for different analytes from different levels within
the same sample. Some  flexibility may be exercised in acceptance of data that are  only  slightly above
(< 10%) the  calibration range.  Such  data are generally acceptable as calculated.
December 1994

-------
 Data Evaluation Guidance
     ,  If data from an analysis of the diluted sample are not provided,  limited use can be made of the
data that are above the-calibration range  (>10%).   The response of  the  analytical  instrument to
concentrations of analytes will eventually level off at concentrations above the calibration range.  While
it is not possible to specify the concentratipn at which this will occur, it  is generally safe to assume that
the reported  concentration above the calibrated range is a lower limit  of the  actual concentration.
Therefore, if the concentration above the calibration range is also above a regulatory limit, it is a virtual
certainty that the actual concentration would also be above that limit.

3.      Linearity of Calibration

        The relationship between the response of an analytical instrument to the concentration or amount
of an analyte introduced into the  instrument is  referred to  as the "calibration curve".  An.analytical
instrument can be said  to be calibrated in any instance in which an instrumental response can be related
to the concentration of an analyte.  The response  factor (RF, calculated for  external standard calibration)
or relative response factor (RRF, calculated for internal standard calibration) is the ratio of the response
of the instrument to the concentration of the analyte introduced  into the instrument.  Equations  for
calculating RFs and RRFs are given in Sections  10.1.1 and 10.1.2 of the QC Supplement.

        While the shape of calibration curves can be modeled by quadratic equations or higher order
mathematical  functions,  most analytical methods focus on a calibration range  in which the linear
calibration is  essentially  a function of the concentration of the analyte.  The advantage of the linear
calibration is that the RF or RRF represents  the slope of calibration curve, simplifying calculations and
data interpretation.   The QC Supplement contains  specific criteria for determining  the linearity of
calibration curves determined by either an internal or external standard technique.   When the applicable
criterion is met, the calibration curve is sufficiently linear to  permit the laboratory to use an average  RF
or RRF, and it is assumed that  the calibration curve  is a straight line that passes through the zero/zero
calibration point.  Linearity is determined by calculating the relative standard deviation (RSD) of the  RF
or RRF for each analyte and comparing this RSD to the specified limit.  The RSD  limits specified in the
QC Supplement are 15%  for the RRF over the calibration range derived using  the  internal standard
technique and 25 % for  the RF over the calibration range derived using the external standard technique.
If the RSD for any metal does not exceed the applicable 15% or 25% criterion, then an averaged RF or
RRF (as appropriate) may be used.

        If the RSD indicates that the calibration is not  linear, then a calibration curve must be used.  This
means that a regression line or  other mathematical function  must be employed to relate the  instrument
response to the concentration. Properly maintained and operated laboratory instrumentation should have
no difficulty in meeting the linearity specifications cited above.

        The  laboratory must provide, the RSD  results  by  which  an independent reviewer can judge
linearity,  even in instances in which the laboratory is using a calibration curve. In these instances,  the
data reviewer should  review  each calibration  point to  assure that  the response  increases as  the
concentration increases.  If it does  not^ the instrument is not operating properly, and the data should  not
be considered valid.
 10                                                                                 December 1994

-------
                                                                          Data Evaluation Guidance
 4.   -  Calibration Verification

        Calibration verification involves the analysis of a single standard, typically in the middle of the
 calibration range, at the beginning (and,  in some cases, at the  end)  of  each analytical shift.   The
 concentration of each analyte in a reference standard is determined using the initial calibration data and
 compared to specifications in the method.   If results are within the specifications,  the laboratory may
 proceed with analysis without recalibrating.  The initial calibration data are then used to quantify sample
 results.

        Calibration verification, which is used in the QC Supplement, differs  in concept and practice from
 "continuing calibration", which is used in the SW-846 methods and in the Superfund Contract Laboratory
 Program (CLP). In continuing calibration, a standard is analyzed and new response factors are calculated
 on the basis of that analysis.  If the new factors are close to the average from the initial calibration, all
 subsequent sample analyses are conducted using the new response factors. The degree of "closeness" is
 generally measured  as  the percent difference between the old  and new factors.   The problem with
 continuing calibration is that it amounts to a daily single-point calibration.  Information about the behavior
 of the instrument at  concentrations above and below this single standard can only be inferred from the
 initial multiple-point calibration.

        The QC Supplement  requires calibration verification after every ten samples.   Calibration
 verification is performed by analyzing an aliquot of the mid-point calibration standard, and obtaining
 results that meet the  specifications contained in Table 2 of the QC Supplement.  These specifications are
given for each method and metal as a percentage of the recovery of the mid-point calibration standard.
 If any individual value falls outside the range given, system performance is considered unacceptable, and
the laboratory may either recalibrate the instrument or prepare a new calibration standard and make a
 second attempt to verify calibration.  The data reviewer should verify that each batch of 10 samples is
associated with a calibration verification that meets the required performance criteria.

5.      Method Detection Limit and Minimum Level

        The Minimum Level (ML) is defined in the QC Supplement as the lowest level at which the entire
analytical system gives a recognizable signal and  acceptable calibration point.  Therefore,  the  QC
Supplement requires that the calibration line or curve for each analyte encompass the ML specified in
Table 1 of that document.

        The QC Supplement also requires each laboratory to perform a  method detection limit (MDL)
 study for each analyte in accordance with the procedures given in 40 CFR Part  136, Appendix B.  The
 MDL studies are conducted to demonstrate that the laboratory can achieve the MDLs  listed in Table 1
 of the QC Supplement.  MDL determinations must be made the first time that the laboratory utilizes the
 method and each time the laboratory utilizes a new instrument or modifies the method in any way.

        Each MDL and ML listed in Table 1  of the QC Supplement represents the results of MDL studies
 conducted by the  EPA's  Engineering and  Analysis Division as part of its effort to validate the QC
 Supplement.  The MDL studies were conducted by at least one laboratory for each method  and metal in
December 1994                                                                                11

-------
Data Evaluation Guidance
accordance with the procedure given in 40 CFR Part 136, Appendix B. The MLs shown in Table 1 were
calculated by multiplying each laboratory-determined MDL by 3.18 and rounding the result to the nearest
multiple of 1, 2,  5,  10, 20,  50, etc. in accordance with the procedures described in the EPA Draft
National  Guidance for the Permitting, Monitoring, and Enforcement of Water  Quality-Based  Effluent
Limitations Set Below Analytical Detection/Quantitation Levels, March 22, 1994.

        The  QC  Supplement  and the Data Reporting Guidelines require the  laboratory to report the
concentration of all sample results  that are at or above  the ML.  It should be noted that this ML is a
sample-specific ML and, therefore, reflects any sample dilutions that were performed.  If sample results
are reported below the ML, the data reviewer should require the responsible party to correct and resubmit
the data, or if this course of action is not possible, the reviewer should determine the sample-specific ML
and consider results below that level to be non-detects for regulatory purposes.

        If sample  results are reported above the ML, but are below the facility's regulatory compliance
level, then the data reviewer should consider the results to suggest that the pollutant has  been detected
but is compliant with the facility's permit (assuming that all QC criteria are met). If sample results are
reported above the regulatory compliance level, the data reviewer must evaluate laboratory QC samples
in order to verify that the  level of  pollutant is not attributable to analytical bias.  In addition, the data
reviewer  must evaluate all blank  sample results in order to ascertain whether the level of pollutant
detected may be attributable to contamination.

        Although sample results are to be reported only if they exceed the ML, all blank results are to
be reported,  regardless of the level.  This reporting requirement allows data reviewers the opportunity
to assess the impact of any blank contamination on sample results that are reported above the ML.

        It is important to remember that if a change that will affect the MDL is made to a method, the
MDL procedure  must be  repeated using the  modified procedure.   Changes may include alternate
digestion,  concentration,  and  cleanup  procedures, and changes   in  instrumentation.   Alternate
determinative techniques, such as the substitution of a colorimetric technique or changes that degrade
method performance are not allowed. The data reviewer should  verify that method modifications were
appropriate and were capable  of producing the desired MDLs.

        The  procedures given in  this document are for evaluation  of  results for determination of
regulatory compliance, and not for assessment of trends,  for triggering, or for other purposes.  For such
other purposes, the reporting of all results, whether negative, zero, below the  MDL, above the MDL but
below  the ML, or above the ML, may be of value and  may be required by the permitting authority as
necessary to  enforce  in a particular circumstance.  Dealing with the  multiplicity of  consequences
presented by such results, either singly or in combination, is beyond the present scope of this document.

6.      Initial Precision and  Recovery

        The laboratory is required to demonstrate its ability to generate acceptable precision and accuracy
data using the techniques specified in the QC Supplement and the referenced method(s). This test, which
is sometimes termed the "start-up test", must be performed by the laboratory prior to the analysis of field
 12                                                                                 December 1994

-------
                                                                         Data Evaluation Guidance
samples with the specified methods and prior to the use of modified versions of the method on field
samples.  EPA's experience has been that laboratories that have difficulty passing the start-up test have
such marginal performance that they will have difficulty in the routine practice of the method.

        The test consists of spiking four aliquots of reagent water with the metals of interest at 2 - 3 times
the ML concentrations listed in Table 1 of the QC Supplement and analyzing these four aliquots. The
mean concentration (x) and the standard deviation (s) are then calculated for each analyte and compared
to the specifications in Table 2 of the QC Supplement. If the mean and the standard deviation are within
the limits, the laboratory can use the method to analyze field samples.

        If the start-up test data fail to meet the specifications in the method,  none of the data produced
by the laboratory can be considered to be valid.  If the laboratory did not perform the start-up tests, the
data cannot be valid, unless all other QC criteria have been met and the laboratory  has submitted IPR
(and associated instrument QC) data that were generated after-the-fact by the same analyst on the same
instrument.  If these conditions are  met, then the data reviewer may consider the data to  be acceptable
for most  purposes.  NOTE:  The inclusion of this alternative should not in any way be construed to
sanction the practice of performing IPR analyses after the analysis of field samples'. Rather,  EPA believes
that demonstration of laboratory capability prior to sample analysis is an essential QC component; this
alternative is provided only as a tool to  permitting authorities when data have already been collected
without the  required IPR  samples.  Once the problem has been identified, all  responsible parties are
expected to implement corrective action necessary to ensure that it is not repeated.

        It is important to remember that  if a change is made to a method, the IPR procedure must be
repeated using the modified procedure. If the start-up test is not repeated when these  steps are modified
or added, any data produced by the  modified methods cannot be considered to be valid.

7.      Analysis of Blanks

        Because trace metals  are ubiquitous in the environment, the precautions necessary to preclude
contamination are more  extensive than those required to preclude contamination when synthetic organic
compounds  and other non-ubiquitous substances are  determined.   EPA has found that the greatest
potential for contamination of samples analyzed for trace metals has been from atmospheric input in the
field and laboratory and from inadequate cleaning of sample bottles and labware.  In order to prove that
such contamination is avoided during sampling, sample transit, and analysis,  Method 1669 and the QC
Supplement specify the collection and analysis of numerous blank samples. These include:

•       Equipment blanks that are collected prior to the use of any sampling equipment at a given site
        and  provide  a means for detecting contamination  of sampling devices and apparatus prior to
        shipment to the field site.

•       Field blanks  that are  collected for each batch of 10  or fewer samples from the same site and
        provide a means of detecting contamination that arises in the field
December 1994   .                                                                   .13

-------
          Data Evaluation Guidance
          •       Calibration blanks that are analyzed immediately after each calibration verification and provide
                 a means of detecting contamination that arises from the analytical system, and

          •       Laboratory (method) blanks that are analyzed for each batch of samples analyzed on a particular
                 instrument and provide a means of detecting contamination from the analytical process.

                 While the analysis of a minimum of four blank samples per site  may seem to be excessive,
          particularly when very few (e.g.,  < 5) samples are collected, EPA has found that the validity of entire
          studies may be suspect when pollutants are identified in samples that are not associated with each of these
          blanks.  In general, it is not  necessary for a facility to  report the  results of equipment blank analyses
          unless contamination is identified in field blanks. Therefore, the permittee should obtain equipment blank
          results from its cleaning facility,  maintain these results on file, and provide  them to the permitting
          authority upon request. The data reviewer should evaluate equipment blank results only if it is necessary
          to identify potential sources of contamination present in  field blanks.

                 Controlling laboratory contamination is an important aspect of the quality assurance plan for the
          equipment-cleaning facility, laboratory, and field team.  Each party should maintain records regarding
          blank contamination. Typically, these records take the form of a paper trail for each piece of equipment
          and control charts, and they should be used to prompt corrective action by the party associated with the
          contamination.  For example,  if records at a single site suggest that equipment blanks, laboratory blanks,
          and calibration blanks are consistently clean but that field blanks show consistent levels of contamination,
          then the  field sampling team should re-evaluate their sample handling procedures,  identify  the problem,
          and institute corrective actions before collecting additional samples.  Similarly, equipment cleaning
          facilities and laboratories should utilize the results of blank analyses to identify and correct problems  in
          their processes.

                 Unfortunately, it is often  too  late for corrective  action if data are received that suggest the
          presence of uncontrolled contamination that adversely affects the associated data.  The exception  to this
          rule is the case in which the  field and equipment blanks show no discernable  levels of contamination,
          contamination is detected in the laboratory or calibration blanks, sample holding times have not expired,
          and sufficient sample  volume remains to allow the laboratory to identify and eliminate the source of
          contamination and reanalyze the associated sample(s).  In all other cases, the reviewer must exercise one
          of several options listed below when making use of the data.

          •       If a contaminant is  present in a blank but is. not present in a sample, then there is little need for
                 concern about the sample result. (It may be useful, however, to occasionally review the raw data
                 for samples without the contaminant to ensure that the laboratory did not edit the results, for this
                 compound.)

          •       If the sample contains the  contaminant at levels  of at least 10 times that in  the blank, then the
                 likely contribution to the sample from the contaminant in the sample is at most 10%. Since most
                 of the methods in question are no more accurate than that level, the possible contamination is
                 negligible, and the data can be considered to be  of acceptable  quality.
          14                                                                                 December 1994
y

-------
                                                                           Data Evaluation Guidance
 •    '  If the sample contains the contaminant at levels of at least 5 times but less than 10 times the blank
        result, the numerical  result in the  sample should be  considered  an upper  limit of the true
        concentration,  and data users should  be cautioned when using  such data for enforcement
        purposes.

 •      If the sample contains the contaminant at levels below 5 times the level in the blank, the sample
        data are suspect unless there are sufficient data from analyses of multiple blanks to perform a
        statistical analysis proving the significance of the analytical result.  Such statistical analyses are
        beyond the scope of this guidance.

 •      If blank contamination is found in some types of QC samples but not others (e.g., only in the
        laboratory blank but not in the field blank), the data user should apply the guidelines listed above,
        but may also use this  information to identify  the  source of contamination and take corrective
        actions to prevent future recurrences.

        There are two difficulties in evaluating sample results relative  to blank contamination.  First, the
 reviewer must be able to associate the samples with the correct blanks. Field blanks are associated with
 each group of field samples collected from the same site. Calibration blanks are associated with samples
 by the date and time of analysis on a specific instrument.  Laboratory (method) blanks are associated with
 each batch of 10 samples prepared and digested in accordance with a particular method during a single
 shift. If the reviewer cannot associate a batch of samples with a given blank, the reviewer should request
 this association from the laboratory so that the results for the samples can be validated.

        The second difficulty involves samples that have been diluted. The dilution of the sample with
 reagent  water represents an additional potential source  of contamination that will not be reflected in the
 results for the blank unless the blank was similarly diluted.  Therefore, in applying the  10-times rule
 stated above, the concentration of the sample is compared to the blank results multiplied by the dilution
 factor of the sample.  For instance, if 1.2 ppb of a contaminant is found in the blank, and  the associated
 sample  was diluted by a factor of six relative to the extract from the blank prior to analysis, then the
 diluted  sample result  would have to be greater than 1.2 x  6 x 10 or 72 ppb to be acceptable.  Diluted
 sample  results between  36 and 72 ppb would be considered an upper limit  of the actual concentration,
 and diluted sample results that were less than 36 ppb would be considered unacceptable in the absence
 of sufficient blank data  to statistically prove the  significance of the result.

        In most cases,  the practice of subtracting the  concentration reported  in  the blank from the
 concentration in the sample is not recommended as a tool to evaluate sample results associated with blank
 data.  One of the most common problems with this approach is that blank concentrations are sometimes
 higher than one or more associated sample results, yielding negative results.

        Blank contamination is usually highly variable, and this variability must be accounted for in order
 for blank-subtraction to be reliable.  A usual solution to this problem is to establish the concentration in
blanks over time and  set the limit on the level above which blank-subtraction may be performed at two
standard deviations above the average blank  level.  However, this approach requires a large data set  to
 be reliable.  Most compliance data are received  as a self-contained data set  with QC data  limited to the
December 1994                                                                                 15

-------
Data Evaluation Guidance
analytical batch in which the samples were analyzed.  As a result, data evaluators are usually not privy
to blank data over time and  cannot therefore perform reliable blank-subtraction using this statistical
approach.  Further, requiring  submission of long-term blank data may unnecessarily complicate the data
reporting process because a determination would need to be made as to which data should be included
or excluded.  Using the ten times rule above provides a more appropriate means of evaluating the results
and does not require the reviewer to alter results reported by the laboratory.

        Nearly all of the methods provided  in the QC Supplement are capable of producing MDLs that
are at least 10 times lower than the lowest water quality criteria (WQC) published in the National Toxics
Rule.  Since most discharge permits require monitoring at levels that are comparable to or higher than
the WQC published in the National Toxics Rule, EPA believes that, in nearly all cases, laboratories
should be capable of producing blank data that are at least 10 times less  than the regulatory compliance
level.  It should also  be  noted that laboratories  cannot be held accountable for contamination that is
present in field blanks but not present in laboratory blanks; in such'cases the sampling crew should take
corrective measures to eliminate the source of contamination during their sample'collection and handling
steps.

8.      Ongoing Precision and Recovery

        The QC  Supplement requires laboratories to prepare and analyze  an "ongoing precision and
recovery" (OPR) sample with each batch of up to 10 samples started through the extraction process on
the same twelve hour shift.  This OPR sample is identical to the aliquots used in the IPR analyses (see
Item 6), and the results of the OPR are used to ensure that laboratory performance is in control during
the analysis of the associated batch of field samples.

        The data reviewer must verify that the OPR sample has been run with each sample batch and that
the applicable recovery criteria in Table 2 of the QC Supplement have been met.  If the recovery criteria
have not been met, the reviewer may use the following guidelines when  making use of the data:

•       If the concentration of the OPR is above method specifications but that analyte is not detected in
        an associated sample, then it unlikely that the sample result is affected by the failure in the OPR.

•       If the concentration of the OPR is above method specifications and that analyte is detected in the
        sample, then the numerical sample result may represent an upper limit of the true concentration,
        and data users should  be cautioned when using the data for enforcement purposes.

•       If the concentration of the OPR is below method specification but that analyte is detected in  an
        associated sample, then the sample result may represent the lower limit of the true concentration
        for that analyte.      ,             '                     ,      •

•       If the concentration of the OPR  is below method specification and that analyte is not detected in
        an  associated  sample,  then  the  sample data are suspect and cannot be considered valid for
        regulatory compliance purposes.
 16                                                                                December 1994

-------
                                                                         Data Evaluation Guidance
      '  If the OPR standard has not been run, there is no way to verify that the laboratory processes were
 in control.  In such cases, a data reviewer may be able to utilize the field sample data by examining the
 matrix spike recovery results (see item 9), the IPR results, OPR results from previous and subsequent
 batches, and any available historical data from both the laboratory and the sample site.  If the matrix
 spike results associated with the sample batch do not meet the performance criteria in Table 2 of the QC
 Supplement, then the results for that set of samples cannot be considered valid.  If the laboratory's IPR
 results and the matrix spike results associated with the sample batch in question meet the all applicable
 performance criteria in Table 2  of the QC Supplement, then the data reviewer may be reasonably
 confident that  laboratory performance was in control during field sample analysis.  This level of
 confidence may be further increased if there is a strong history of both laboratory performance with the
 method and method performance with the sample matrix in question, as indicated by additional OPR and
 matrix spike data collected from the laboratory and samples from the same site.

 9.      Precision and Recovery of Matrix Spike and Matrix Spike Duplicate Compounds

        The QC Supplement and the referenced methods require that laboratories spike the analytes of
 interest into duplicate aliquots of at least one sample from each group of ten samples  collected from a
 single site.  The first of these spiked sample aliquots is known as the matrix spike sample; the second is
 known as the matrix spike duplicate.   These.spiked sample aliquots are used to determine if the method
 is applicable to the sample matrix in question. The analytical procedures described in the QC Supplement
 and the referenced methods are applicable to the determination of metals at concentrations typically found
 in ambient water samples and certain treated effluents (e.g.,  the part-per-trillion to low part-per-billion
 range).   These methods  may not be  applicable to  marine samples and many effluent and in-process
 samples collected from industrial dischargers. Therefore, it is important to evaluate method performance
 in the sample matrix of interest.

        In evaluating matrix spike sample results,  it is important to examine both the precision and
accuracy of the duplicate analyses. Precision is assessed by examining the relative percent difference
(RPD) of the concentrations found in the matrix spike and matrix spike duplicate samples, and comparing
the RPD to the acceptance criteria specified in the referenced method.  If an RPD acceptance criteria is
 not specified in the referenced method, the QC Supplement requires the RPD results to be less than 20%.
 If the RPD of a matrix spike/matrix spike duplicate pair exceeds the applicable criterion, then the method
cannot be considered to be applicable to the sample matrix, and none of the associated sample data can
 be accepted  for regulatory compliance purposes.

        If RPD criteria are met, the method is considered to be capable of producing precise data in these
 samples, and the data reviewer must  then verify that the method is capable of producing accurate data..
 Accuracy is  assessed by examining the recovery of compounds  in the matrix spike  and matrix spike
 duplicate samples.  If the recovery of the matrix spike and duplicate are within the limits specified in the
 method  or the QC Supplement, then the method is judged to be  applicable to that sample matrix.  If,
 however, the recovery of the spike is not within the recovery range specified, either the method does not
 work on the sample, or the sample preparation process is  out of control.
December 1994                                                                                 17

-------
            Data Evaluation Guidance
                 ,  If the method is not appropriate for the sample matrix, then changes to the method are required.
            Matrix spike results are necessary in evaluating the modified method.  If the analytical process is out of
            control, the laboratory must take immediate corrective action before any more samples are analyzed.

                    To separate indications of  method performance from  those of laboratory performance,  the
            laboratory should prepare and analyze calibration verification standards and OPR samples. * If the results
            for either of these analyses are not within the specified range, then the analytical system or process must
            be corrected.  After the performance of the analytical system and processes have been verified (through
            the successful analysis of CCV and OPR samples), the spike sample analysis should be repeated. If the
            recovery of  the  matrix spike and  duplicate are  within the  range specified in Table  2  of the QC
            Supplement, then the method and laboratory performance can be considered acceptable. If, however, the
            recovery of the matrix spike does not meet the specified range, the laboratory should attempt to further
            isolate the metal and repeat the test.  If recovery of the metal remains outside the acceptance criteria, the
            data reviewer may apply the. following guidelines when attempting to make use of the data:

            •       If the recovery of the matrix spike and duplicate are above method specifications but that metal
                    is not detected in an associated sample or is detected below the regulatory compliance limit, then
                    it unlikely that the sample result is affected by the failure in the  matrix spike.

            •      If the recovery of the matrix spike and duplicate are above method specifications and that metal
                   is detected in an associated sample above the regulatory compliance level, then the sample result
                   may represent the upper limit  of the true concentration, and the data should not be considered
                   valid for regulatory compliance purposes.

            •      If the concentration of the matrix spike and duplicate  are below method specifications but that
                   metal is detected in an associated sample, then the sample result may represent the  lower limit
                   of  the  true concentration  for  that metal.   If  the metal  was detected in the sample at a
                   concentration higher than the regulatory compliance limit, then it is unlikely that the sample result
                    is adversely affected by the  matrix.  If, however, the metal was detected below the regulatory
                    compliance limit, the data should not be considered valid for regulatory compliance purposes.
            10.     Statements of Data Quality for Spiked Sample Results

                    The QC Supplement specifies that after the analysis of five spiked samples of a given matrix type,
            a statement of data quality is constructed for each analyte.  The statement of data quality for each analyte
            is computed as the mean percent recovery plus and minus two times the standard deviation of the percent
            recovery for the analyte.  The statements of data quality should then be updated by the laboratory after
            each five to ten subsequent spiked sample analysis.

                    The statement of  data quality can be used to estimate the true value of a reported result and to
            construct confidence bounds  around the result.  For example, if the  result  reported for analysis of
            selenium is 10 ppb,  and the  statement of  data quality for selenium is 84%  ±25% (i.e., the mean
            18                                                                                 December 1994
I2.S

-------
                                                                          Data Evaluation Guidance
 recovery is 84 % and the standard deviation of the recovery is 25 %), then the true value for selenium will
 be in the range of 9.4 -  14.4 ppb, with 95% confidence. This range is derived as follows:

        Lower Limit  = [(10 + .84) - (10 x .25)] ~ [11.9 - 2.5]  = 9.4 ppb
        Upper Limit  = [(10  -s- .84) + (10 x .25)] = [11.9 + 2.5] = 14.4 ppb

        Many laboratories do not provide the data quality statements with the sample results, in which
 case the data reviewer must determine if the data quality statements  are being maintained for each analyte
 and may need to obtain the data. If necessary, the reviewer can construct the data quality statement from
 the individual data points. The lack of a data quality statement does  not invalidate results but makes some
 compliance decisions  more difficult.  If statements of data quality are not being maintained by the
 laboratory, there may be increased concern about both specific sample results and the laboratory's overall
 quality assurance program.

 11.     Statements of Data Quality for Spiked Reagent Water Results

        In addition to statements of data quality for results of analyses of the compounds spiked into field
 samples, the QC Supplement requires that statements of data quality be constructed from the initial and
 ongoing precision and recovery data.  The purpose of these statements is to assess laboratory performance
 in the practice of the  method, as compared to the  assessment of method performance made from the
 results of spiked field samples.  Ideally, the two statements of data quality would be the same.  Any
 difference is attributable to either random error or sample matrix effects.

 12.     Field Duplicates

        Method 1669 requires the collection of at least one field duplicate for each batch of field samples
 collected from the same site. The field duplicate provides an indication of the overall precision associated
with entire data gathering effort, including sample collection, preservation,  transportation, storage, and
analysis procedures.  The data reviewer should examine field duplicate  results  and  use the following
equation to calculate the relative percent difference between the duplicate and its associated samples.
                                     RPD  -
                                                  (D1+D2)
        where:
        Dl = concentration of the analyte in the MS sample
        D2 = concentration of the analyte in the MSD sample
December 1994              -                                                                 19

-------
Data Evaluation Guidance
        If the analyte of interest was not detected in either replicate of the field sample, then the RPD
will be zero.  If the analyte was detected  in each  field sample replicate, but the results are highly
disparate (indicated by  a large RSD), the reviewer should apply the following guidelines when making
use of the data:

•       If the analyte was detected in each replicate and at similarly variable concentrations in the blank
        samples, then the field sample variability may be attributable to variable contamination, and the
        data may not be valid for regulatory compliance purposes.

•       If the  analyte  was detected in each replicate at a  concentration well above the regulatory
        compliance level, but was not detected in the associated blank samples, then it is likely that the
        sample results are not adversely affected.

        Ideally, the RPD between field duplicates and MS/MSD samples will be identical.  Any difference
between the two is attributable to variability associated with the field sampling process.
20                                                                                 December 1994

-------
                                                                             Chapter 4

                                                                Data Inspection Checklist
       The following pages contain a data inspection checklist that may be used by data reviewers,
laboratory personnel, and other parties to document the results of each data inspection in a standardized
format.
December 1994                                                                           21

-------
                                       Data Inspection Checklist
                                         Summary Information
    1.. Name of Reviewer:
               Title:
                   Required Samples •
                          Sample Results Provided
    Sample Location or Sample ID
Analyte(s)
Sample Location or Sample ID
Analyte(s)
   2.  Method Used:

   3.  Total No. of analytical shifts per instrument (determined from analysis run log):
           Instrument
              No. of Shifts
   4.  Total No. of CCVs Required:       	
   (one for each 10 samples after the
   first 10 samples on each instrument)

   5.  Total No. of CCBs Required:       	
   (one for each CCV)

   6.  Total No. of Field Blanks Required: 	
   (one per site or per  10 samples,  whichever is more
   frequent).
   7.  Total no. of Lab Blanks Required:
   (one per batch* per method/instrument)
    8.  Total no. of OPR analyses Required:_
    (one per batch per method/instrument)
    9.  Total no. of MS/MSD samples Required:
    (one per 10% per matrix per site)
              Total No. of CCVs Reported:
              Total No. of CCBs Reported:
              Total No. of Field Blanks Reported:
              Total No. of Lab Blanks Reported:
              Total No. of OPR Analyses Reported:
              Total No. of MS/MSD samples Reported^
    10.  Total no. Field Duplicates Required:
    (one per 10 samples per site)

    11.  Total no. of MDL results required:
    (one per method and per analyte)
              Total No. of Field Duplicates Reported:
              Total No. of MDL Results Reported:
22
                                                December 1994

-------
                                         Data Inspection Checklist
     12.


      »
     a.

     b.
    c.
                                 Initial Calibration


Was a multiple-point initial calibration performed"?                         Dyes    Dno

Were all sample concentrations reported within the calibration .range?         Dyes    Ono

If no. list method and analytes for which initial calibration was not performed or which
exceeded the calibration range.'

Analvte     No ICAL (Y/N1      Exceeded ICAL Ranee (Y/N)
    d.

    e.
Did the initial calibration meet linearity criteria?

If no, was a calculation curve used to calculate sample concentrations?
Dyes   Dno
    * A three point (minimum) initial calibration should be performed for each analyte; if the RSD of the mean RRF is less than 15%,
    or if the RSD of the mean RF is less than 25%, then the averaged RRF or RF, respectively, may be used for that analyte.
    13.                     Method Detection Limit (MDL)/Minimum Level (ML)


    a.       Did the laboratory demonstrate their ability to achieve the required MDL?    Dyes   Dno

    b.       Did the initial calibration range encompass the ML?                         Dyes   Dno

    c.       Were all field samples detected below the ML reported as non-detects?       Dyes   Dno

    d.       If the answer to item a, b,  or c above was "no", describe problem:
December 1994
                                                                                           23

-------
                                      Data Inspection Checklist
    14.              Initial Calibration Verification (ICV)/Initial Calibration Blanks (ICB):


    a.      Was an ICV run prior to field samples?                                  Dyes   Dno
     »

    b.      Were ICV results within the specified windows?                          Dyes   Dno


    c.      Was the ICV followed by an ICB?                                      Dyes   Dno


    d.      Was the ICB free from contamination?                                  Dyes   Dno


    e.      If any item in a  - d above was answered "no", list problems below:

                                                               #
           Analvte   Failed ICV Recovery Concentration Detected in ICB    Affected Samples
   15.                            Initial Precision and Recovery (IPR)


   a.      Were IPR data reported for each analyte?                                Dyes   Dno


   b.      Did all IPR aliquots meet required recovery criteria (x)?                   Dyes   Dno


   c.-      Did the standard deviation (s) of each IPR series meet the required criterion? Dyes   Dno


   d.      If any item in a - d above was answered "no", document problem below.


           Analvte Ave. Result Reported (X)       RSD Reported     Affected Samples
   16.                          Ongoing Precision and Recovery (OPR)


   a.      Was OPR data reported for analyte, instrument, and batch?                 Dyes   Dno


   b.      Did all OPR samples meet.required recovery criteria (x)?                  Dyes   Dno


   c.      If item a or b above was answered "no", document problem below.


           Analvte OPR Recovery (X) Reported      Shifts Missing OPR  Affected Samples
24                                                                                   December 1994

-------
                                      Data Inspection Checklist
    17.        Continuing Calibration Verification (CCV)/Continuing Calibration Blank (CCB)




    a.,     Were CCVs run prior to each batch of 10 samples on each instrument?      Dyes   Dno




    b.       Were all CCV results within the specified windows?                       Dyes   Dno




    c.       Was each CCV followed by a CCB?                                    Dyes   Dno




    d.       Was each CCB free from contamination?                                Dyes   Dno




    e.       If any item in a - d above was answered  "no", list problems below:




            Analvte Affected Samples        Shift Missing CCV/CCB       Failed CCV/CCB ID
    18.                               Laboratory (Method) Blanks




    a.      Was a method blank analyzed for each instrument & sample batch?




    b.      Was each method blank demonstrated to be free from contamination?




    c.      If the answer to item a or b was "no", document problems below.




           Analvte    Affected Samples        Blank Concentration Reported
    Dyes   Dno




    Dyes   Dno




    Dyes   Dno




Shift Missing MB
    19.                                     Field Blanks




    a.      Was a field blank analyzed for each 10 samples per site?




    b.      Was each field blank demonstrated to be free from contamination?




    c.      If the answer to item a or b was "no", document problems below.




           Analvte    Affected Samples        Blank Concentration Reported
    Dyes   Dno




    Dyes   Dno




    Dyes   Dno




Shift Missing FB
December 1994
                    25

-------
                                                  Data Inspection Checklist
                20.


                •a.'

                b.

                c.

                d.
                               MS/MSD Results


Were appropriate number of MS/MSD pairs analyzed?                     Dyes   Dno

Were all MS/MSD recoveries  within specified windows?                   Dyes   Dno

Were all RPDs within the specified window?                             Dyes   Dno

Was appropriate corrective action (e.g., MSA for.GFAA, serial dilution
for ICP) employed on affected samples?                                  Dyes   Dno

If the answer was "no" to items a - d above, document affected samples:
                        Analyte MS % R
                       MSP % R
MS/MSD RPD    Affected Samples
                21.                                 Additional Information


                a.      Were Instrument Tune Data Provided?                                  Dyes   Dno

                b.      Were equipment blanks demonstrated to be free from contamination?         Dyes   Dno

                c.      Were statements of data quality provided?                               Dyes   Dno

                d.      Did field duplicate demonstrate acceptable precision?                      Dyes   Dno
I3C
             26
                                                                         December 1994

-------
                  APPENDIX A




              Analytical Laboratories




EPA Office of Water, Engineering & Analysis Division

-------
                                   Analytical Laboratories
During the course of its efforts to develop guidance for the analysis of trace metals at ambient water
quality levels, the EPA Engineering and Analysis Division's Analytical Methods Staff has identified
several laboratories that are currently determining certain trace metals at ambient water quality levels.
These laboratories are  identified below for informational purposes only.  This does not represent an
exhaustive list, nor does it constitute an EPA endorsement of any laboratory appearing on the list.
Axis Environmental Systems, Ltd.
P.O. Box 2219
2045 Mill Road
Sydney, BC Canada V8L 3S8
Contact:  Mary McFarland
Phone:  604/656-0881

Battelle/Marine Sciences Laboratory
1529 West  Sequim Bay Road
Sequim, WA 98382
Contact:  Eric  Crecelius
Phone:  206/683-4151

Battelle Ocean Sciences
397 Washington Street
Duxbury, MA  02332
Contact:  Dion Lewis; Carlton Hunt
Phone: 617/934-0571
University of California/Santa Cruz
Environmental Toxicology
Santa Cruz, CA 95064
Contact:  Russell Flegal; Kenneth Bruland
Phone: 408/459-2093

University of Connecticut
Department of Marine Sciences
1084 Shennecossett Road
Groton, CT 06340-6097
Contact:  William Fitzgerald
Phone: 203/446-1020

Department of Oceanography
Florida State University
Tallahassee, Florida 32306-3048
Contact:  Bill Landing
Phone: 904/644-6037

College of Marine Studies
University of Delaware
Lewes, DE 19538
Contact:  Thomas M. Church
Phone: 302/645^253
Frontier GeoSciences
414 Pontius North
Seattle, WA 98109
Contact: Nicholas Bloom
Phone:  206/622-6960
Old Dominion University
Department of Oceanography
Norfolk, VA 23529
Contact: Greg Cutter
Phone:  804/683-4285

Texas A&M University at Galveston
Department of Marine Sciences
5007 Avenue U
Galveston, TX 77553-1675
Contact: Gary Gill
Phone:  409/740-4710

Texas A&M University
Department of Oceanography
College Station, TX 77843-3146
Contact: Paul  Boothe
Phone:  409/845-5137

Skidaway Institute of Oceanography
P.O. Box 13687
Savannah, Georgia 31416
Contact: H.L. Windom
Phone:  912/598-2490
Green Meadows Laboratory
363 W. Drake Road
Fort Collins, CO 80526
Contact:  Rod Skogerboe
Phone: 303/223-9828

Research Triangle Institute
Institute Drive, Building 6
Research Triangle Park, NC 27709
Contact:  Peter Grohse
Phone: 919/541-6190

-------
                  APPENDIX B

  Office of Water Interim Guidance Concerning the
      Collection of Metals Data at WQC Levels
                (November 8, 1994)

EPA Office of Water, Office of Science & Technology

-------
              UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                         WASHINGTON, O.C. 20460
                                                            OFFICE OF
                                                            WATER
                            . NOV  8 1994
MEMORANDUM
SUBJECT:   Interim Guidance Concerning the Collection of Metals
           Data at WQC Levels

TO:        Water Division Directors

FROM:      Tudor Davies,  Director
           Office of Science and Technology


SUMMARY

     As we discussed during our last meeting, the Office of
Science and Technology's Engineering and Analysis Division (EAD)
has been engaged in the  development of guidance to support the
Office of  Water's policy regarding the implementation of water
quality criteria (WQC) for metals.   These efforts include the
development of sampling  and analysis methods, and of data
reporting  and  review guidelines.    Draft sampling and analysis
methods have been completed and have been subjected to limited
peer review within and outside of the Agency.  These methods are
currently  undergoing validation and more extensive peer review.
Draft data reporting guidelines have also been developed and will
serve as a cornerstone for the forthcoming data review
guidelines.  A schedule  of projected completion dates for each of
these efforts  is provided as Attachment 1 to this memo.  Copies
of the draft sampling method and the quality control supplement
are also attached.

     During the development of the methods and guidance described
above, EAD has fielded numerous questions from Regional and State
offices regarding interim measures that these offices can take to
maximize the quality of  trace metals data that they are currently
gathering  or will be gathering in the near future.  The remainder
of this memorandum addresses these questions and is intended to
serve as interim guidance to Regional and State permitting staff
until completion and issuance of the guidance and methods cited
above.


                                                     Recyctod/ftecyclabto
                                                     Prinwd with Soy/C«noi« Mi on p*Mr M
                                                     contain* « tout 50% nKydod fib*
                                                                   •   / fJ

-------
IHTERZM GUIDANCE

     The following is  a  list  of  activities or areas that should
assist Regional  and State  offices  in obtaining reliable metals
data.  Please hdte that, in some instances, the information that
is referenced is contained in the  draft sampling and analysis
guidance documents that  are provided in Attachment 2.  The Office
of Science and Technology  emphasizes that the information in this
memo and in the  draft  guidance is  guidance.  It is intended to
assist Regional  and State  personnel and does not constitute
formal Agency policy at  this  time.

Awareness;  Two  of the most important  factors in avoiding/
reducing sample  contamination are  (1)  an awareness of potential
sources of contamination,  and (2)  strict attention to work being
performed.  For  this reason,  we  recommend that all permitting and
monitoring staff become  aware of the activities necessary to
prevent sample contamination  by  reading the draft EAD sampling
and analytical guidance  and the  technical literature on
determination of metals  at trace levels.  In order to minimize
the cumulative effects of  contamination from multiple sources,
sample and laboratory  staff should be  instructed to implement as
many aspects of  the guidance  as  are feasible in their current
activities.  Guidance  aspects that EAD believes may be most
critical in reducing or  minimizing the potential for
contamination.include  the  following:

     Preparing samples and standards in a controlled area:
     Exposure of samples,  standards, and blanks to the atmosphere
     is one of the most  common ways of introducing contamination.
     Therefore,  samples  and standards  should be prepared in a
     controlled  area.  Preferably, this controlled area is a
     clean room,  a clean bench,  or a glove box.

     Cleaning sample bottles  and labware:  EAD has found that all
     researchers performing trace  metals analyses agree on the
     need for extensive  procedures for bottle cleaning.  While
     the actual  cleaning procedures used by researchers vary
     (from boiling in  nitric  acid  for  8 hours, to soaking in 50
     °C nitric acid for  two weeks  followed by storage filled with
     dilute hydrochloric acid),  all procedures used are exten-
     sive.  We highly  recommend  that such extensive procedures be
     implemented in any  interim  data gathering efforts.

     Wearing gloves and  changing gloves when a potential source
     of contamination  has  been touched:  Although not absolutely
     necessary,  the discipline of  wearing gloves brings with it
     an awareness that samples can be  contaminated.  Further, the
     use of gloves is  simple, inexpensive, and may serve to
     reduce the  cumulative effects of  contamination to levels
     that will not have  an adverse impact on data quality.

     Using metal"free  apparatus:  In addition to inspecting all
     apparatus that the  sample will contact for the presence of

-------
     metals, procedures should be  in place to make sure that the
     surfaces  that  the sample will touch will not contact metals.

Analyzing Blanks;   Results of the  analysis of equipment blanks
will inform the equipment cleaning facility that the cleaning
processes are  in control.  These results should be used to
facilitate corrective actions prior to sample collection.
Similarly, results  of analysis of  laboratory blanks will inform
the analyst and the laboratory quality assurance officer (QAO)
that laboratory operations are in  control.  These results should
be used to facilitate corrective actions prior to completion of
sample analysis.  Finally, analysis of field and laboratory
blanks will enable  the data user to assess the source, extent,
and impact of  contamination (if any).

QC Data;  The  ability to assess data quality is directly linked
to the presence of  QC data.  Therefore, we highly recommend that,
as a minimum requirement, all new  data gathering efforts include
the collection, analysis, and evaluation of QC samples described
in the draft guidance documents.   These QC samples include
equipment, field, laboratory, and  calibration blanks,
demonstrations of instrument calibration and calibration
verification,  demonstrations of initial and ongoing laboratory
precision and  accuracy through the analysis of IPR and OPR (or
equivalent) samples, and demonstration of method precision and
accuracy (through the analysis of  matrix spike/matrix spike
duplicate samples).

     Many EPA  methods provide either performance data or
performance criteria for certain QC elements.  Unless program-
specific performance criteria have been developed for the data in
question, data users should review the QC data against the
criteria provided in the QC Supplement included with this
guidance.  These criteria were developed based on data from
determination  of the analytes in multiple matrices,  and are an
attempt to reflect  the somewhat additional variability that can
be expected when trace metals are  determined at or near ambient
water quality  criteria levels.  If the QC Supplement does not
contain QC criteria, and if program-specific criteria have not
been developed, OST recommends that the data user evaluate QC
data against criteria provided in  an alternate EPA method that
utilizes similar analytical procedures.

     Regardless of  the specifications contained in the method,
OST recommends that data users adhere to the following guidelines
concerning the presence of contamination in blank samples:

     Ideally,  all blank samples should be free from contamination
     above the Method Detection Level (MDL)  or estimated MDL for
     the analyte in the method.

     If blank  contamination is present, but it is present at a
     level that is  at least 10 times less than the levels in
     associated field samples, we  believe that the field sample

-------
     data are of acceptable quality.

     If blank contamination is present, but it is present at a
    . level that is between 5 and 10 tines less than the levels in
     the associated  field samples, we believe that the sample
     data may be biased high, and data users should be cautioned
     when using such data for enforcement purposes.

     If blank contamination is present, but is present at a level
     that is between 1 and 5 times less than the level in the
     sample, data should be suspect unless there are sufficient
     data from analyses of multiple blanks to perform a
     statistical analysis proving the significance of the
     analytical result.  Such statistical analyses are beyond the
     scope of this guidance.

     If blank contamination is found in some types of QC samples
     but not others  (e.g., only in the laboratory blank but not
     in the field blank), the data user should apply the
     guidelines listed above, but may also use this information
     to identify the source of contamination and take corrective
     actions to prevent future recurrences.

     If supporting QC data are not present and cannot be
obtained, the data user must recognize that the analytical result
may be valid but that validity cannot be proved,  and that no
statement can be made regarding data quality.  An exception to
this situation is one in which long-term monitoring data are
available and the long term data are associated with QC data that
demonstrate data validity.  If this circumstance exists, and if a
single result is missing associated QC data but is statistically
consistent with the  validated long-term data, the data user may
reasonably make the  assumption that the single value is valid.
Note, however, that  the presence of unvalidated long-term
monitoring data does not pr.ovide any level of certainty.  Long-
term data may be continuously biased by contamination or other
failures if the data are continuously generated using the same
procedures.  Without QC data to support the long-term monitoring
data, there is no way to assess long-term data validity.

If you have any questions regarding the information contained in
this memo, please contact Bill Telliard of HAD at 202/260-7134.

Attachments

cc:  Environmental Services Division Directors, RO I - X
     Enforcement Division Directors, OECA
     Tom O'Farrell
     Sheila Frace
     Betsy Southerland
     Margaret Stasikowski
     Mike Cook
     Cynthia Dougherty
     Dana Minerva

-------
                     Attachment 1

Projected Schedules and Activities for Development of
              EAD Trace Metals Guidance

-------
                                   Engineering and Analysis Division
                                        Analytical Methods Staff
              Projected Schedules and Activities for Development of Trace Metals Guidance
                                           October 31, 1994

Sampling Guidance

•       A draft sampling method was  completed in January 1994; this version and subsequent revisions (now
        referred to as EPA Method 1669) have been subjected to limited peer review within and outside the
        Agency.  The most recent draft is undergoing more extensive peer review.

•       Final revision of sampling guidance incorporating clean techniques from USGS and other experts will be
        completed by December 1994.

•       Development of guidance for effluent sampling will be completed by January 1995.

Analytical Methods

•       New analytical methods for determination of most metals at WQC levels will be available by the end of
        December 1994.

                Validation of Quality Control Supplement for Determination of Metals at Ambient Water Quality
                Criteria Levels Using EPA Methods is underway for 10 metals; revision of the QC Supplement
                to reflect the validation study will be completed by December 1994.

                New EPA methods that incorporate the procedures  in the final version of the QC Supplement will
                be available by March 1995.

•       Methods are currently under development for

                Arsenic, Chromium (III) and Mercury

                Draft methods  will be completed by December 1994

                Method validation activities will be conducted in early FY95

•       Interlaboratory studies of all new  methods will be initiated in FY95

Data Reporting and Data Review Guidance

•       Draft data  reporting guidelines have  been developed to serve as the foundation for draft data review
        guidance.  The data reporting guidelines are designed to capture all data elements necessary to assess and
        define data quality.

•       Data review guidelines  are  scheduled  for completion in FY95.

Other Activities

•       An ORD report evaluating clean  rooms will be  released in October 1994.  EAD  will  issue guidance on
        upgrading existing laboratory facilities for clean techniques in December.

•       A Trace Metals Workshop for State and Regions is scheduled to be held in conjunction with the Norfolk
        Conference in May 1995.

-------
                APPENDIX C

Office of Water Policy and Technical Guidance on
      Interpretation and Implementation of
          Aquatic Life Metals Criteria
               (October 1, 1993)

             EPA Office of Water

-------
                    UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                                  WASHINGTON. D.C. 20460
                                        OCT   1  693
                                                                         OFFCEOF
                                                                          WATER
 MEMOR A NDUM
 SUBJECT:   Office of Water Policy and Technical Guidance on Interpretation and
              Implementation of Aquatic Life Metals Criteria
FROM:       Martha G. Prothro
              Acting Assistant Administrator for Water

TO:          Water Management Division Directors
              Environmental Services Division Directors
              Regions l-X

Introduction

       The implementation of metals criteria is complex due to the site-specific nature of
metals toxicity.  We have undertaken a number of activities to develop guidance in this area,
notably the Interim Metals Guidance, published May 1992, and a public meeting of experts
held in Annapolis, MD, in January 1993.  This memorandum transmits Office of Water
(OW) policy and guidance on the interpretation and implementation of aquatic life criteria for
the management of metals and supplements my April 1,  1993, memorandum on the same
subject.  The issue covers a number of areas including the expression of aquatic life criteria;
total maxirflum daily loads (TMDLs), permits, effluent monitoring, and compliance; and
ambient monitoring. The memorandum covers each in turn.  Attached to this policy
memorandum are three guidance documents with additional technical details.  They are:
Guidance Document on Expression of Aquatic Life Criteria as Dissolved Criteria
(Attachment #2), Guidance Document on Dynamic Modeling and Translators  (Attachment
#3), and  Guidance Document on Monitoring (Attachment #4). These will be  supplemented
as additional data become available. (See the schedule in Attachment #1.)

       Since metals toxicity is significantly affected by site-specific factors, it presents a
number of programmatic challenges.  Factors that must be considered in the management of
metals in the aquatic environment include:  toxicity specific to effluent chemistry; toxicity
specific to  ambient water chemistry; different patterns of toxicity for different metals;
evolution of the state of the  science of metals toxicity, fate, and transport; resource
limitations for monitoring, analysis, implementation, and research functions; concerns
regarding some of the analytical data currently on record due to possible sampling and
analytical contamination; and lack of standardized protocols for clean and ultraclean metals
analysis. The States have the key role in the risk management process of balancing these
factors in the management of water programs.  The site-specific  nature of this issue could be
perceived as requiring a permit-by-permit approach to implementation.  However, we believe

-------
 that this gtvdance can be effectively implemented on a broader level, across any waters with
 roughly the same physical and chemical characteristics, and recommend that we work with
 the States with that perspective in mind.

 Expression of Aquatic Life Criteria

 o      Dissolved vs. Total Recoverable Metal

        A major issue is whether, and how, to use dissolved metal concentrations ("dissolved
 metal") or total recoverable metal concentrations ("total recoverable metal") in setting State
 water quality standards. In the past, States have used both approaches when applying the
 same Environmental Protection Agency (EPA) criteria numbers.  Some older criteria
 documents may have facilitated these different approaches to interpretation of the criteria
 because the documents were somewhat equivocal with regards to analytical methods.  The
 May 1992 interim guidance continued the policy that either approach was acceptable.

        It is now the policy of the Office of Water that the use of dissolved metal to set and
 measure compliance with water quality standards is the recommended approach, because
 dissolved metal more closely approximates the bioavailable fraction of metal in the water
 column than does total recoverable metal.  This conclusion regarding metals bioavailability is
 supported by a majority of the scientific community within and outside the Agency. One
reason  is that a primary mechanism for water column toxiciry is adsorption at the gill  surface
which requires metals to be in the dissolved form.

       The position that the dissolved metals approach is more accurate has been questioned
because it neglects the possible toxicity of paniculate metal.  It is true that some studies  have
 indicated that paniculate metals appear to contribute to the toxicity of metals,, perhaps
because of factors such as  desorption of metals at the gill surface, but these, same studies
indicate the toxicity of paniculate metal is substantially less than that of dissolved metal.

        Furthermore, any error incurred from excluding the contribution of paniculate  metal
 will generally be compensated by other factors which make criteria conservative. For
 example, metals in toxicity tests are added as simple salts to relatively clean water.  Due to
 the likely presence of a significant concentration of metals binding agents in many discharges
and ambient waters, metals in toxiciry tests would generally be expected to be more
bioavailabile than metals in discharges or in ambient waters.

        If total recoverable metal is used for the purpose of water quality standards,
compounding of factors  due to the lower bioavailability of paniculate metal and lower
bioavailability of metals as they are discharged may result in a conservative water quality
 standard. The use of dissolved metal in water quality standards gives a more accurate result.
However, the majority of the participants at the Annapolis meeting felt that total recoverable
 measurements in ambient water had some value, and that exceedences of criteria on a  total ^
 recoverable basis  were an  indication that metal loadings could be a stress to the ecosystem^
 particularly in locations  other than the water column.

-------
        The reasons for the potential consideration of total recoverable measurements include
  risk management considerations not covered by evaluation of water column toxicity.  The
  ambient water quality criteria are neither designed nor intended to protect sediments, or to
  prevent effects due to food webs containing sediment dwelling organisms. A risk manager,
  however, may consider sediments and food chain effects and may decide to take a
  conservative approach for metals, considering that metals are very persistent chemicals.  This
  conservative approach could include the use of total recoverable metal in water quality
  standards.  However, since consideration  of sediment impacts is not incorporated into the
 criteria methodology, the degree of conservatism inherent in the total recoverable approach is
 unknown. The uncertainty of metal impacts in sediments stem from the lack of sediment
 criteria and an imprecise understanding of the fate and transport of metals.  EPA will
 continue  to pursue research and other activities to close these knowledge gaps.

        Until the scientific uncertainties are better resolved,  a range of different risk
 management decisions can be justified.  EPA recommends that State water quality standards
 be based  on  dissolved metal.  (See the paragraph below and the attached guidance for
 technical  details on developing dissolved criteria.)  EPA will also approve a State risk
 management decision to adopt standards based on total recoverable metal, if those standards
 are otherwise approvable as a matter of law.

 o     Dissolved Criteria

       In the toxicity tests used to develop EPA metals criteria for aquatic life, some fraction
 of the metal  is dissolved while some fraction is bound to paniculate matter.  The present
 criteria were developed using total recoverable metal measurements or measures expected to
 give equivalent results in toxicity tests, and are articulated as total recoverable.  Therefore,
 in order to express the EPA criteria as dissolved, a total recoverable to dissolved correction
 factor must be used.  Attachment 82 provides guidance for calculating EPA dissolved.criteria
 from the published total recoverable criteria. The data expressed as percentage metal
dissolved  are presented as recommended values and ranges.  However, the choice within
ranges is a State risk management decision. We have recently supplemented the data for
copper and are proceeding to further supplement the data for copper and other metals.  As
testing is completed, we will make this information available and this is expected to reduce
the magnitude of the ranges for some of the conversion factors provided. We also strongly
encourage the application of dissolved criteria across a watershed or waterbody, as
technically sound and the best use of resources.

o     Site-Specific Criteria Modifications

       While the above methods will correct some site-specific factors affecting metals
toxicity, further refinements are possible.  EPA has issued guidance (Water Quality
Standards Handbook, 1983; Guidelines for Deriving Numerical Aquatic Site-Specific Water
Quality Criteria by Modifying National Criteria, EPA-600/3-H4-099, October 1984) for three
site-specific criteria development methodologies:  recalculation procedure, indicator species
procedure (also known as the water-effect ratio (WER)) and resident species procedure.
Only the first two of these have been widely used.

-------
        In the National Toxics Rule (57 FR 60848, December 22,  1992), EPA identified the
 WER as an optional method, for site-specific criteria development for certain metals. EPA
 committed in the NTR preamble to provide guidance on determining the WER.  A draft of
 this guidance has been circulated to the States and Regions for review and comment. As
 justified by water characteristics and as recommended by the WER guidance, we strongly
 encourage the application of the WER across a watershed or waterbody as opposed to
 application on a discharger by discharger basis, as technically sound and an efficient use of
 resources.

       In order to meet current needs, but allow for changes suggested by protocol users,
 EPA will issue the guidance as "interim." EPA will accept WERs developed using this
 guidance, as well as by using other scientifically defensible protocols.  OW expects the
 interim WER guidance will be issued in the next two months.

 Total Maximum Daily Loads fTMDLsl and National Pollutant Discharge Elimination System
 (NPDES> Permits

o      Dynamic Water Quality Modeling

       Although not specifically part of the reassessment of water quality criteria for metals,
 dynamic or probabilistic models are another useful tool for implementing water quality
criteria, especially for those criteria protecting aquatic  life. These models provide another
 way to incorporate site-specific data.  The 1991 Technical Support Document for Water
Quality-based Toxics Control (TSD) (EPA/505/2-90-001) describes dynamic, as well as static
(steady-state) models. Dynamic models make the best use of the specified magnitude,
duration, and frequency of water quality criteria and, therefore, provide a more accurate
 representation of the probability that a water quality  standard exceedence will occur.  In
contrast, steady-state models make a number of simplifying, worst case assumptions which
makes them less complex and less  accurate than dynamic models.

       Dynamic models have received increased attention over the last few years as a result
of the widespread belief that steady-state modeling is over-conservative due to
environmentally conservative dilution assumptions. This belief has led to the misconception
that dynamic models will always lead to less stringent regulatory controls (e.g., NPDES
effluent limits) than steady-state models, which is not true in every application of dynamic
 models.  EPA considers dynamic models to be a more accurate approach to implementing
 water quality criteria and continues'to recommend their use. - Dynamic modeling does require
commitment of resources to develop appropriate data.  (See Attachment #3 and the TSD for
 details on the use of dynamic models.)

 o      Dissolved-Total Metal Translators

       Expressing water quality criteria as the dissolved form of a metal poses a need
 able to translate from dissolved metal to total recoverable metal for TMDLs and  NPD
permits. TMDLs for metals must be able to calculate: (1) dissolved metal in order to
 ascertain attainment of water quality standards, and  (2) total recoverable metal in order to
 achieve mass balance necessary for permitting purposes.

-------
        EPA's NPDES regulations require that limits of metals in permits be stated as total
 recoverable in most cases (see 40 CFR §122.45(c)) except when an effluent guideline
 specifies the limitation in another form of the metal, the approved analytical methods
 measure only dissolved metal, or the permit writer expresses a metals limit in another form
 (e.g., dissolved, valent, or total) when required to carry out provisions of the Clean Water
 Act. This is because the chemical conditions in ambient waters frequently differ substantially
 from those in the effluent, and there is no assurance that effluent paniculate metal would not
 dissolve after discharge.  The NPDES rule does not require that State water quality standards
 be expressed as total recoverable; rather, the rule  requires permit writers to translate between
 different metal forms in the calculation of the permit limit so that a total recoverable limit
 can be established.  Both the TMDL and NPDES  uses of water quality criteria require the
 ability to translate between  dissolved metal and total recoverable metal.  Attachment #3
 provides methods for this translation.

 Guidance on Monitoring

 o      Use of Clean Sampling and Analytical Techniques

       In assessing waterbodies to determine the potential for toxicity problems due to
 metals, the quality of the data used is an important issue. Metals data are used to determine
attainment status for water quality standards, discern trends in water quality, estimate
background loads for TMDLs, calibrate fate and transport models,  estimate effluent
concentrations (including effluent variability), assess permit compliance, and conduct
 research. The quality of trace level metal data, especially below 1  ppb, may be
compromised due to contamination of samples during collection, preparation, storage, and
analysis.  Depending on the level of metal present, the use of "clean" and "ultraclean"
techniquesTor sampling and analysis may be critical to accurate data for implementation of
aquatic life criteria for metals.

       The magnitude of the contamination problem increases as the ambient and effluent
metal concentration decreases and, therefore, problems are more likely in ambient
measurements.   "Clean" techniques refer to those requirements (or  practices for sample
collection and handling) necessary to produce reliable analytical data in the part per billion
(ppb) range. "Ultraclean" techniques refer to those requirements or practices necessary to
produce reliable analytical data in the part per trillion (ppt) range.  Because typical
concentrations of metals in surface waters and effluents vary from one metal to another, the
effect of contamination on the quality of metals monitoring data varies appreciably.

       We plan to develop protocols on the use of clean and ultra-clean techniques and are
coordinating with the United States Geological Survey (USGS) on this project, because USGS
has been doing work on these techniques for some time, especially the sampling procedures.
We anticipate that our draft protocols for clean techniques will be available in late calendar
year 1993.  The development of comparable protocols for ultra-clean techniques is underway
and will be available in 1995. In developing these protocols,  we will consider the costs of
these techniques and will give guidance as to the situations where their use is necessary.
 Appendix B to the WER guidance document provides some general guidance on the use of
                                                                                        7

-------
 clean analytical techniques.  (See Attachment #4.)  We recommend that this guidance be used
 by States and Regions as an interim step, while the clean and ultra-clean protocols are being
 developed.

 o      Use of Historical Data

        The concerns about metals sampling and analysis discussed above raise corresponding
 concerns about the validity of historical data.  Data on effluent and ambient metal
 concentrations are collected by a variety of organizations including Federal agencies (e.g.,
 EPA. USGS), State pollution control agencies and health departments, local government
 agencies, municipalities, industrial dischargers, researchers, and others.  The data are
 collected for a variety of purposes as discussed above.

       Concern about the reliability of the sample collection and analysis procedures is
 greatest where they have been used to monitor very low level metal concentrations.
 Specifically, studies have shown data sets with contamination problems during sample
 collection and laboratory analysis, that have resulted in inaccurate measurements. For
 example, in developing a TMDL for New York Harbor, some historical  ambient data showed
 extensive metals problems in the harbor, while other historical ambient data showed only
 limited metals problems.  Careful resampling and analysis in 1992/1993 showed  the latter
 view  was correct.  The key to producing accurate data is appropriate quality assurance (QA,
and quality control (QQ procedures. We believe that most historical data for metals,
collected and analyzed with appropriate QA and QC at levels of 1  ppb or higher, are
 reliable. The data used in development of EPA criteria are also considered reliable, both
because they meet the above test and because the toxicity test solutions are created by adding
known amounts of metals.

       With_respect to effluent monitoring reported by an NPDES permittee, the permittee is
responsible for collecting and reporting quality data on a Discharge Monitoring Report
 (DMR). Permitting authorities should continue to consider the information reported to be
true, accurate, and complete as certified by the permittee.  Where  the permittee becomes
aware of new information specific to the effluent discharge that questions the quality of
previously submitted DMR data, the permittee must promptly submit that information to the
permitting authority.  The permitting authority will consider all information submitted by the
permittee in determining appropriate enforcement responses to monitoring/reporting and
effluent violations.  (See Attachment i4 for additional details.)

Summary

       The management of metals in the aquatic environment is complex. The science
supporting our technical and regulatory programs is continuing to evolve, here as in all
areas. The policy and guidance outlined above represent the position of OW and should be
 incorporated into ongoing program operations. We do not expect that ongoing operations
would be delayed or deferred because of this guidance.                                i

-------
        If you have questions concerning this guidance, please contact Jim Hanlon, Acting
 Director, Office of Science and Technology, at 202-260-5400. If you have questions on
 specific details of the guidance, please contact the appropriate OW Branch Chief.  The
 Branch Chiefs responsible for the various areas of the water quality program are:  Bob April
 (202-260-6322,  water quality criteria), Elizabeth Fellows (202-260-7046, monitoring and data
 issues), Russ Kinerson (202-260-1330, modeling and translators), Don Brady (202-260-7074,
Total Maximum Daily Loads),  Sheila Frace (202-260-9537, permits), Dave Sabock
(202-260-1315, water quality standards), Bill Telliard (202-260-7134, analytical methods)
and Dave Lyons (202-260-8310, enforcement).
Attachments

-------
                                                                 ATTACHMENT #1

                       TECHNICAL GUIDANCE FOR METALS

                           Schedule of Upcoming Guidance
Water-effect Ratio Guidance - September 1993


Draft "Clean" Analytical Methods - Spring 1994
Dissolved Criteria - currently being done; as testing is completed, we will release the
updated percent dissolved data
Draft Sediment Criteria for Metals - 1994


Final Sediment Criteria for Metals - 1995

-------
                          ATTACHMENT #2
   GUIDANCE DOCUMENT
  ON DISSOLVED CRITERIA
Expression of Aquatic Life Criteria
         October 1993

-------
                                                           10-1-93


       Percent Dissolved in Aquatic Toxicity Tests on Metals


 The attached table contains all the data that  were found
 concerning the percent of the total recoverable metal that was
 dissolved in aquatic toxicity tests.   This table  is intended to
 contain the available data that are relevant to the conversion  of
 EPA's aquatic life criteria for metals from a  total recoverable
 basis to a dissolved basis.   (A factor of 1.0  is  used to convert
 aquatic life criteria for metals that  are expressed on the basis
 of  the acid-soluble measurement to criteria expressed on the
 basis of the total recoverable  measurement.)   Reports by Grunvald
 (1992)  and Brungs  et al.  (1992)  provided references to many of
 the documents in which pertinent data  were found.   Each  document
 was obtained and examined to determine whether it  contained
 useful data.

 "Dissolved"  is  defined as metal  that passes through a  0.45-pm
 membrane filter.   If otherwise  acceptable, data that were
 obtained using  0.3-pm  glass  fiber filters and 0.1-^m membrane
 filters  were  used,  and are identified  in the table;  these  data
 did not  seem  to  be outliers.

 Data were used only if the metal was in a dissolved  inorganic
 form when it  was added to  the dilution water.  In addition, data
were used only if  they were  generated  in water that would have
been acceptable  for use as a dilution water in tests used in the
derivation of water quality  criteria for aquatic life; in
particular, the pH had to  be between 6.5 and 9.0,  and the
concentrations of total organic carbon  (TOG) and total suspended
solids  (TSS)  had to be below 5 mg/L.  Thus most data generated
using rrver water would not  be used.

Some data were not used for  other reasons.  Data presented by
 Carroll  et al.  (1979)  for  cadmium were not used because 9 of the
 36  values were above  150%.   Data presented by Davies et al.
 (1976) for lead  and Holcombe and Andrew (1978)  for zinc were not
used because  "dissolved" was defined on the basis of
polarography, rather than  filtration.

Beyond this,  the data  were not reviewed for quality.  Horowitz et
al.  (1992) reported that a number of aspects of the filtration
procedure might affect the results.  In addition,  there might be
concern  about use of "clean  techniques" and adequate QA/QC.

Each line in  the table is  intended to represent a separate piece
of  information.  All of the data in the table were determined in
 fresh water,  because no saltwater data were found.  Data are
becoming available for copper in salt water from the New York

-------
 Harbor study; based on the first set of tests,  Hansen (1993)
 suggested that the average percent of the copper that is
 dissolved in' sensitive saltwater tests is in the range of 76 to
 82 percent.

 A thorough investigation of the percent of total recoverable
 metal that is dissolved in toxicity tests might attempt to
 determine if the percentage is affected by test technique
 (static,  renewal, f low- through ), feeding (were  the test animals
 fed and,  if so,  what food and how much) ,  water  quality
 characteristics  (hardness,  alkalinity,  pH, ' salinity) ,  test
 organisms (species,  loading) ,  etc.

 The attached table also gives the freshwater  criteria
 concentrations (CMC and CCC)  because percentages  for total
 recoverable concentrations  much (e.g., more than  a factor  of 3)
 above or  below the CMC and  CCC are  likely to  be less relevant.
 When a criterion is expressed as a  hardness equation, the  range
 given extends from a hardness of 50 mg/L  to a hardness of  200
 rog/L.

 The following is a summary  of  the available information  for each
 metal:
The data available  indicate that the percent dissolved is about
100, but all the available data are for concentrations that are
much higher than the CMC and CCC.


CadmjuTO
        — j,   .      '                                         /
Schuytema et al. (1984) reported that "there were no real
differences" between measurements of total and dissolved cadmium
at concentrations of 10 to 80 ug/L (pH - 6.7 to 7.8, hardness »
25 mg/L, and alkalinity « 33 mg/L); total and dissolved
concentrations were said to be "virtually equivalent1*.

The CMC and .CCC are close together and only range from 0.66 to
8.6 ug/L.  The only available data that are known to be in the
range of the CMC and CCC were determined with a glass fiber
filter.  The percentages that are probably most relevant are 75,
92, 89, 78, and 80.


Chromium f III 1

The percent dissolved  decreased as the total recoverable
concentration  increased, even though the highest concentrations
reduced the pH substantially.  The percentages that are probab;

-------
 roost relevant to the CMC are 50-75, wherean the percentages that
 are probably most relevant to the CCC are 86 and 61.


 Chromium(VI)

 The data available indicate that the percent dissolved is about
 100,  but all the available data are for concentrations that are
 much higher than the CMC and CCC.


 Copper

 Howarth and Sprague  (1978)  reported that the total and dissolved
 concentrations of copper were  "little different" except when the
 total  copper concentration  was  above 500 ug/L at hardness  « 360
 ng/L and pH = 8  or 9.   Chakoumakos  et al.  (1979) found that the
 percent dissolved depended  more on  alkalinity than on  hardness,
 pH, or the  total recoverable concentration of copper.
                                                                /
 Chapman (1993) and Lazorchak (19S7)  both found that the addition
 of daphnid  food  affected the percent dissolved very little,  even
 though Chapman used yeast-trout chow-alfalfa whereas Lazorchak
 used algae  in most tests, but yeast-trout chow-alfalfa  in  some
 tests.   Chapman  (1993)  found a  low percent dissolved with  and
 without food, whereas Lazorchak (1987) found a high percent
 dissolved with and without  food.  All of Lazorchak's values  were
 in high hardness water;  Chapman's one value in high hardness
 water was much higher than  his other values.

 Chapman (1993) and Lazorchak (1987) both compared the effect of
 food on the total recoverable LC50 with the effect of food on the
 dissolved LC50.  Both authors found that food raised both the
 dissolved LC50 and the total recoverable LC50 in about the ,same
 proportion,  indicating that food did not raise the total
 recoverable LC50 by sorbing metal onto food particles; possibly .
 the food raised  both LCSOs by (a)  decreasing the toxicity of
 dissolved metal,  (b) forming nontoxic dissolved complexes with
 the metal,  or (c) reducing uptake.

The CMC and CCC  are close together and only range from 6.5 to 34
ug/L.   The  percentages that are probably most relevant are 74,
 95, 95,  73,  57,  53, 52,  64, and 91.


 Lead

The data presented in Spehar et al.  (1978)  were from Holcombe et
 al. (1976).  Both Chapman (1993) and Holcombe et al.  (1976)  found
 that the percent dissolved  increased as the total recoverable
 concentration increased.  It would seem reasonable to expect more
 precipitate at higher total recoverable concentrations and

-------
 therefore a lower percent dissolved at higher concentrations.
 The increase in percent dissolved with increasing  concentration
 might be due to a lowering of the pH as more metal is  added  if
 the stock solution was acidic.

 The percentages that are probably most relevant to the CMC are 9,
 18,  25,  10,  62, 68,  71,  75,  81,  and 95,  whereas the percentages
 that are probably most relevant to the CCC are 9 and 10.


 Mercury

 The only percentage  that is  available  is 73,  but it is for a
 concentration  that is much higher than the CMC.


 Nickel

 The  percentages that are probably most relevant to the CMC are
 88,  93,  92,  and 100,  whereas the  only percentage that is probably
 relevant to  the CCC  is 76.


 Selenium

No data  are  available.


 Silver

There is a CMC,  but not  a CCC.  The percentage dissolved seems to
be greatly reduced by  the food used to feed daphnids,  but not by
 the  food used  to feed  fathead minnows.   The percentages that are
probably~most  relevant to the CMC are 41, 79, 79,  73,  91, 90, and
 93.


 Zinc

The  CMC  and  CCC are close together and only range from 59 to 210
ug/L.  The percentages that  are probably most relevant are 31,
 77,  77,  99,  94,  100,  103, and 96.

-------
  Recommended Values (*)A and Ranges  of  Measured Percent: Dissolved
             ' Considered Most Relevant  in Fresh Water
   Metal                   £M£                   CC£

                  Recommended           Recommended
                   Value f%l (Ranoc %1   Value f%l  fRanae
Arsenic (III)
Cadmium
Chromium (II I)
Chromium (VI )
Copper
Lead
Mercury
Nickel
Selenium
Silver
Zinc
95
85
85
95
85
50
85
85
NAE
85
85
100-104*
75-92
50-75
100*
52-95
9-95
73*
88-100
NAC
41-93
31-103
95
85
85
95
85
25
NAE
85
NAE
YY°
85
100-1048
75-92
61-86
100B
52-95
9-10
NAE
76
NAC
YYD
31-103
A The recommended values are based on current knowledge and are
  subject to change as more data becomes available.

8 All available data are for concentrations that are much higher
  than the CMC.
                                                          ^
c NA - No data are available.

0 YY » A CCC is not available, and therefore cannot be adjusted.

E NA - BioaccumuLative chemical and not appropriate to adjust to
  percent dissolved.

-------
Concn.A
fua/Ll
Percent
Diss.1 nc
Soecies0
ARSENlCfllll { Freshwater: CCC «
600-15000
12600
CADMIUM
0.16
0.28
0.4-4.0
13
15-21
42
10
35
51
6-80
3-232
450-6400
104 5
100 3
(Freshwater:
41 ?
75 ?
92° ?
89 3
96 8
84 4
78 ?
77 ?
59 ?
80 8
90H 5
70 5
?
FM
CCC - 0.66
DM
DM
CS
FM
FM
FM
DM
DM
DM
?
?
FM
SRFB Food Hard. Alk. Efl
190 ug/L; CMC = 360 ug/L)
?
F
to 2.0
R
R
F
F
S
S
S
S
S
S
F
F
7
No
ug/L;
Yes
Yes
No
No
No
No
No
No
No
No
?
No
48
44
CMC «
53
103
21
44
42
45
51
105
209
47
46
202
41
43
1.8
46
83
19
43
31
41
38
88
167
44
42
157
7.6
7.4
to 8.6
7.6
7.9
7.1
7.4
7.5
7.4
7.5
8.0
8.4
7.5
7.4
7.7
Ref.
Lima et al. 1984
Spehar and Fiandt 1986
ug/L)'
Chapman 1993
Chapman 1993
Finlayson and Verrue 1982
Spehar and Fiandt 1986
Spehar and Carlson 1984
Spehar and Carlson 1984
Chapman 1993
Chapman 1993
Chapman 1993
Call et al. 1982
Spehar et al. 1978
Pickering and Cast 1972

-------
             (Freshwater:  CCC - 120 to 370 ug/L;; CMC = 980 to 3100 ug/L)'
5-13
19-495
>1100

42
114
16840
26267
27416
58665
CHROMIUM
>25,000
43,300
CQEEEB
10-30
40-200
30-100
100-200
20-200
40-300
94 ?
86 ?
50-75 ?
CA ?
3H *
HI ">
61 i
26 ?
32 ?
27 ?
23 ?
(VI) (Freshwater
100 1
99.5 4
(Freshwater: CCC
74 ?
78 ?
79 ?
82 ?
86 ?
87 ?
SG
SG
SG
DM
DM
fc/1 1
DM
DM
DM
DM
: ccc •
FM.GF
FM
• 6.5
CT
CT
CT
CT
CT
CT
F
It
F
R
R

S
S
S
S
=• 11
F
F
?
?
NO
Yes
Yes

No
No
No
No
ug/L; CMC
Yes
No
25
25
25
206
52

<51
110
96
190
«= 16
220
44
to 21 ug/L; CMC = 9
F
F
F
F
F
F
No
No
NO
No
No
NO
27
154
74
192
31
83
24
24
24
166
45

9
9
10
25
ug/L)
214
43
.2 to
20
20
23
72
78
70
7.3
7.2
7.0
8.2
7.4

6.3'
6.7
6.01
6.2'

7.6
7.4
Stevens and Chapman
Stevens and Chapman
Stevens and Chapman
Chapman 1993
Chapman 1993

Chapman 1993
Chapman 1993
Chapman 1993
Chapman 1993

1984
1984
1984





Adelman and Smith 1976
Spehar and Fiandt 1986
34 ug/L)p
7.0
6.8
7-6
7.0
8.3
7.4
Chakoumakos et al.
Chakoumakos et al.
Chakoumakos et al.
Chakoumakos et al.
Chakoumakos et al.
Chakoumakos et al.
1979
1979
1979
1979
1979
1979
10-80
89
                         CT
                                       NO
                                    25
169   8.5   Chakoumakos et al. 1979

-------
300-1300
100-400
1-4'
L2-911
L8-19
201
50
1751
5-52
*r ^f **
6-80
6.7
35
13
^k V
16
A v
51
32
W •»
33
•* •*
39
25-84
17
120
15-90
12-162
28-58
26-59
56,101
92 ?
94 ?
125-167 2
79-84 3
95 2
95 1
96 2
91 2
>82K ?
83° ?
57 ?
43 ?
73 ?
57 ?
39 ?
53 ?
52 ?
64 ?
96 14
91 6
88 14
74 19
80M ?
85 6
79 7
86 2
CT
CT
CD
CD
DA
DA
FM
FM
FM
CS
DM
DM
DM
DM
DM
DM
DM
DM
FM,GM
DM
SG
?
BG
DM
DM
DM
F
F
R
|R
s
R
S
R
F
F
S
S
R
R
R
S
S
S
S
S
S
S
F
R
R
R
No
No
Yes
Yes
No
No
No
No
YesL
No
No
Yes
Yes
Yes
Yes
No
No
No
No
NO
NO
No
YesL
No
YesM
AA
YesM
195
70
31
31
52
31
52
31
47
21
49
48
211
51
104
52
105
106
50
52
48
48
45
168
168
168
160
174
38
38
55
38
55
38
43
19
37
39
169
44
83
45
79
82
40
43
47
47
43
117
117
117
7.0
8.5
7.2
7.2
7.7
7.2
7.7
7.2
8.0
7.1
7.7
7.4
8.1
7.6
7.8
7.8
7.9
8.1
7.0
7.3
7.3
7.7
7-8
8.0
8.0
8.0
Chakoumakos et al. 1979
Chakoumakos et al. 1979

Carlson et al. 1986a,b
Carlson et al. I986a,b
Carlson et al. 1986b
Carlson et al. I986b :
Carlson et al. 1986b .
Carlson et al. 1986b

Lind et al. 1978
Finlayson and Verrue 1982

Chapman 1993
Chapman 1993

Chapman 1993
Chapman 1993
Chapman 1993

Chapman 1993
Chapman 1993
Chapman 1993

Hanmermeister et al.  1983
Hammermelster et al.  1983
Hamroermelater et al.  1983

Call et al.  1982

 Benoit 1975

 Lazorchak 1987
 Lazorchak 1987
 Lazorchak 1987

-------
96
160
230-3000
86
94
>69->79
4
1
?
FM
FM
CR
F
S
F
No
No
No
44
203
17
43
171
13
7.4
8.2
** • «b
7.6
 17
181
193

 612
 952
1907

7-29

34
58
119
235
474
4100

2100
       (Freshwater:  CCC « 1.3

            9       ?       DM
           18       ?       DM
           25       ?       DM

           29       ?       DM
           33       ?       DM
           -38      ?       DM

           10       ?       E2

           62"      ?       BT
           68"      7       BT
           71M      ?       BT
           75M      ?       BT
           81H      ?       BT
           82M      ?       BT
220-2700
580
           79

           96
           95
7      FM

14  FM,GM,DM
14     SG
               R
               R
               R

               S
               S
               S
               F
               F
               F
               F
               F
               F
S
S
No
No
,; CMC
Yes
Yes
Yes
No
No
No
No
Yes
Yes
Yes
Yes
Yes
No
No
No
No
203
17
- 34
52
102
151
50
100
150
22
44
44
44
44
44
44
44
49
51
171
13
to 200
47
86
126
•• 
-------
NICKEL   (Freshwater: CCC  •>  88  to 280 ug/L;  CMC «= 790 to 2500  ug/L)F
21
150
578
645
1809
1940
2344
81 ?
76 ?
87 ?
88 ?
93 ?
92 ?
100 ?
DM
DM
DM
DM
DM
DM
DM
R
R
p
s
s
s
s
Yes
Yes
Yes
No
No
No
No
51
107
205
54
51
104
100
49
87
161
43
44
84
84
7.4
7.8
8.1
7.7
7.7
8.2
7.9
4000
90
PK
NO
21
Chapman 1993
Chapman 1993
Chapman 1993

Chapman 1993
chapman 1993
Chapman 1993
Chapman 1993

JRB Associates 1983
SELENIUM  (FRESHWATER: CCC -  5 ug/L;  CMC «  20 ug/L)

No data are available.

0.19
9.98
4.0
4.0
3
2-54
2-32
4-32
5-89
6-401
^
74 1
13 1
41 1
11 i
79 1
79 1
73 1
91 1
90 1
93 1
\
r DM
p DM
? DM
r DM
? FM
r FM
P FM
P FM
> FM
r FM

s
s
s
s
s
s
s
s
s
s
_,
No
Yes
No
Yes
No
Yes0
No
No
No
No

47
47
36
36
51
49
50
48
120
249

37
37
25
25
49
49
49
49
49
49

7.6
7.5
7.0
7.0
8.1
7.9
8.1
8.1
8.2
8.1
»»«i
Chapman 1993
Chapman 1993
Nebeker et al.
Nebeker et al.
UWS 1993
UWS 1993
UWS 1993
UWS 1993
UWS 1993
UWS 1993



1983
1983






                                             1Q

-------
      (Freshwater: CCC -  59  to 190 ug/L;  CMC 65  to 210  ug/L)f
52
62
191
356
551
741
7'
1B-2731
1671
180
188-3931
551
40-500
1940
5520
<4000
>4000
160-400
240
31
77
77
74
78
76
71-129
81-107
99
94
100
100
95°
100
83
90
70
103
96
?
?
?
?
?
?
2
2
2
1
2
1
?
?
7
?
?
13
13
DM
DM
DM
DM
DM
DM
CD
CD
CD
CD
FM
FM
CS
AS
AS
FM
FM
FM,GM,DM
SG
R
R
P
0
S
s
S
R
R
R
S
R
S
F
F
F
F
F
S
S
Yes
Yes
Yes
No
No
No
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
211
104
52
54
105
196
31
31
31
52
31
52
21
20
20
204
204
52
49
169
83
47
47
85
153
38
38
38
55
38
55
19
12
12
162
162
43
46
8.2
7.8
7.5
7.6
8.1
8.2
7.2
7.2
7.2
7.7
7.2
7.7
7.1
7.1
7.9
7.7
7.7
7.5
7.2
                                                               Chapman  1993
                                                               Chapman  1993
                                                               Chapman  1993

                                                               Chapman  1993
                                                               Chapman  1993
                                                               Chapman  1993

                                                               Carlson  et al.  1986b
                                                               Carlson  et al.  1986b

                                                               Carlson  et al.  I986b
                                                               Carlson  et al.  1986b

                                                               Carlson  et al.  1986b
                                                               Carlson  et al.  1986b

                                                                Finlayson and Verrue 1982

                                                                Sprague  1964
                                                                Sprague  1964

                                                                Mount 1966
                                                                Mount 1966

                                                                Hammermeister et al. 1983
                                                                Hammermeister et al. 1983
A Total recoverable concentration.

• Except as noted, a 0.45-fim membrane  filter was used.
                                             11

-------
c Number of paired comparisons,

0 The abbreviations used are:
         AS
         BT
         CD
         CR
         CS
         CT
Atlantic salmon           DM » Daphnia magna
Brook trout               EZ » Elassoma zonatum
Ceriodaphnia dubia I      FH » Fathead minnow
Crayfish                  GF » Goldfish
Chinook salmon            GN - Gammarid
Cutthroat trout           PK « Palaemonetes kadiakenaia
         DA - Daphnids                  SG - Salmo gairdnerj,

e The abbreviations used are:
         S - static
         R - renewal
         F - flow-through

* The two numbers are for hardnesses of 50 and 200 mg/L, respectively.

0 A 0.3-pm glass fiber filter was used.

H A 0.10-pm membrane filter was used.

1 The pH was below 6.5.

' The dilution water was a clean river water with TSS and Toe below 5 mg/L.

K Only limited information is available concerning this value.

L It is assumed that the solution that was filtered was from the test chambers that
  contained fish and food.

M The food was algae.

H The food was yeast-trout chow-alfalfa.

0 The food was frozen adult brine shrimp.

-------
 References' •


 Adelman, I.R..,  and L.L. Smith, Jr.   19*76.  Standard Test Fish
 Development.  Part I. Fathead Minnows fPimephales promelas) and
 Goldfish rcarassius auratusl as Standard Fish in Bioassays and
 Their Reaction  to Potential Reference Toxicants.  EPA-600/3-76-
 06la.  National Technical Information Service,  Springfield, VA.
 Page 24.

 Benoit,  D.A.  1975.   Chronic Effects of  Copper  on Survival,
 Growth,  and Reproduction of the Bluegill (Lepomis joacrochirus).
 Trans.  Am. Fish.  Soc.  104:353-358.

 Brungs,  W.A., T.S. Holderman,  and M.T. Southerland.   1992.
 Synopsis of Water-Effect Ratics for  Heavy Metals as  Derived for
 Site-Specific Water  Quality Criteria.

 Call, D.J., L.T.  Brooke,  and D.D. Vaishnav.   1982.   Aquatic
 Pollutant Hazard  Assessments and Development  of a Hazard
 Prediction Technology  by Quantitative Structure-Activity
 Relationships.  Fourth Quarterly Report.  University of
 Wisconsin-Superior,  Superior, WI.

 Carlson, A.R.,  H. Nelson, and D. Haamermeir-ter.   19S6a*
 Development and Validation  of Site-Specific Water Quality
 Criteria for  Copper.   Environ. Toxicol. Chem. 5:997-1012.

 Carlson, A.R.,  H. Nelson, and C. Hammermeister.   1986b.
 Evaluation of Site-Specific Criteria for Copper  and  Zinc: An
 Integration of  Metal Addition Toxicity, Effluent and Receiving
Water Toxicity, and  Ecological Survey Data.  EPA/600/S3-86-026.
National- Technical Information Service, Springfield, VA.

 Carroll, J.J.,  S.J.  Ellis,  and W.s. Oliver.  ,1979.   Influences  of
Hardness Constituents  on the Acute Toxicity of Cadmium to Brook
Trout (Salvelinus /ontinalis).

 Chakoumakos, C., R.C.  Russo, and R.V. Thurston.   1979.  Toxicity
 of Copper to Cutthroat Trout (Salao clarJci) under Different
Conditions of Alkalinity, pH, and Hardness.  Environ. Sci.
Technol. 13:213-219.

 Chapman, G.A.   1993.   Memorandum to C. Stephan.   June 4.

 Davies,  P.H., J.P. Goettl,  Jr., J.R. Sinley, and N.F. Smith.
 1976.  Acute  and  Chronic Toxicity of Lead to Rainbow Trout  Salmo
 gairdnari, in Hard and Soft Water.  Water Res.  10:199-206.

 Finlayson, B.J.,  and K.M Verrue.  1982.  Toxicities  of Copper,
 Zinc, and Cadmium Mixtures  to Juvenile Chinook  Salmon.  Trans.
 Am.  Fish. Soc.  111:645-650.

                                13

-------
 Geckler, J.R., W.B. Horning, T.M.  Neiheisel,  Q.H.  Pickering, E.L.-
 Robinson, and C.E. Stephan.  1976.   Validity  of Laboratory Tests
 for Predicting Copper Toxicity in  Streams.  EPA-600/3-76-116.
 National Technical Information Service,  Springfield,  VA.  Page
 118;

 Grunwald, 0.  1992.  Metal Toxicity Evaluation:  Review, Results,
 and Data Base Documentation.

 Hamnermeister, D., C.  Northcott, L.  Brooke,, and D.  Call.  1983.
 Comparison of Copper,  Lead and Zinc Toxicity  to Four  Animal
 Species  in Laboratory and ST.  Louis River Water.   University of
 Wisconsin-Superior,  Superior,  WI.

 Hansen,  D.J.   1993.  Memorandum to  C.E. Stephan.  April 15.

 Holcombe,  G.W.,  D.A. Benoit, E.K. Leonard, and J.M. McKim.   1976.
 Long-Term Effects of Lead Exposure on Three Generations of  Brook
 Trout  (Salvelinus fontinalis).  J. Fish. Res. Bd. Canada 33:1731-
 1741.

 Holcombe,  G.W.,  and R.W.  Andrew.  1978.  The Acute Toxicity of
 Zinc to  Rainbow  and Brook Trout.  EPA-600/3-78-094.   National
Technical  Information  Service,  Springfield, VA.

Horowitz,  A.J.,  K.A. Elrick, and M.R. Colberg.  1992.   The  EffecJ
of Membrane  Filtration Artifacts on Dissolved Trace Element
Concentrations.   Water Res.  26:753-763.

Howarth, R.S., and J.B. Sprague.  1978.  Copper Lethality to
Rainbow  Trout  in Waters on Various Hardness and pH.  Hater Res.
 12:455-462.

JRB Associates.   1983.  Demonstration of the Site-specific
 Criteria Modification  Process:  Selser's Creek, Ponchatoula,
Louisiana;

Lazorchak, J.M.   1987.  The Significance of Weight Loss of
Daphni,a  maana  Straus During Acute Toxicity Tests with Copper.
 Ph.D. Thesis.

 Lima, A.R.,  C. Curtis, D.E. Hammermeistcr, T.P. Mark.ee,  C.E.
 Northcott, L.T.  Brooke.   1984.  Acute and Chronic Toxicities  of
Arsenic(III) to  Fathead Minnows, Flagfish, Daphnids,  and an
Amphipod.  Arch.  Environ.  Contam. Toxicbl. 13:595-601.

 Lind, D.,  K. Alto, and S.  Chatterton.  1978.  Regional  Copper-
Nickel Study.  Draft.

 Mount, D.I.   1966.  The Effect  of Total Hardness and  pR on Acute
 Toxicity of  Zinc to Fish.  Air  Water Pollut. Int. J.  10:49-56.


                                14

-------
 ttebeker, A...V., C.K. McAuliffe, R. Mshar,  and  D.G.  Stevens.   1983.
 Toxicity of Silver to Steelhead and Kainbow Trout, Fathead
 Minnows, and Daphnia magna.  Environ. Toxicol. Chem. 2:95-104.

 Pickering,  Q.P., and M.H. Cast.  1972.  Acute and  Chronic
 Toxicity of Cadmium to the Fathead Minnow  (Pimephales pronelas).
 J. Fish. Res.  Bd. Canada 29:1099-1106.

 Rice,  D.W.,  Jr., and F.L. Harrison.   1983.  The Sensitivity of
 Adult,  Embryonic, and Larval Crayfish Procaabarus clarJcii to
 Copper.   NUREG/CR-3133 or UCRL-53048.   National Technical
 Information Service,  Springfield,  VA.

 Schuytema,  G.S.,  P.O.  Nelson, K.W. Malueg, A.V.  Nebeker, D.F.
 Krawczyk, A.K.  Ratcliff,  and J.H.  Gakstatter.   1984.   Toxicity of
 Cadmium  in  Water and Sediment Slurries to Daphnia magna.
 Environ.  Toxicol. Chem.  3:293-308.

 Spehar,  R.L., R.L.  Anderson,  and J.T.  Fiandt.   1978.   Toxicity
 and Bioaccumulation of Cadmium and Lead in Aquatic Invertebrates.
 Environ.  Pollut.  15:195-208.                                    .

 Spehar, R.L., and A.R.  Carlson.  1984.   Derivation of Site-
 Specific Water  Quality Criteria  for Cadmium and the St.  Louis
 River Basin, Duluth,.Minnesota.  Environ.  Toxicol.  Chem.  3:651-
 665.

 Spehar, R.L., and J.T. Fiandt.  1986.  Acute and  Chronic Effects
 of Water Quality  Criteria-Based Metal Mixtures on Three  Aquatic
 Species.  Environ. Toxicol. Chem. 5:917-931.

 Sprague, J.B.   1964.  Lethal  Concentration of  Copper  and Zinc for
 Young Atlantic  Salmon.  J. Fish. Res. Bd.  Canada  21:17-9926.

 Stevens, D.G.,  and G.A. Chapman.  1984.  Toxicity of  Trivalent
 Chromium to Early Life Stages of Steelhead Trout.   Environ.
Toxicol. Chem.  3:125-133.

University of Wisconsin-Superior.  1993.   Preliminary data from
work assignment 1-10 for  Contract No. 68-C1-0034.
                                15

-------
                                                             ATTACHMENT
                               GUIDANCE DOCUMENT
                   ON DYNAMIC MODELING AND TRANSLATORS
                                      August 1993
 Total Maximum Daily Loads (TMDLs) and Permits

 o      Dynamic Water Quality Modeling

        Although not specifically pan of the reassessment of water quality criteria for metals,
 dynamic or probabilistic models are another useful tool for implementing water quality
 criteria, especially those for protecting aquatic life.  Dynamic models make best use of the
 specified magnitude, duration, and frequency of water quality criteria and thereby provide a
 more accurate calculation of discharge impacts on ambient water quality. In contrast, steady-
 state modeling is based on various simplifying assumptions which makes it less complex and
 less accurate than dynamic modeling.  Building on accepted practices in water resource
 engineering, ten years ago OW devised methods allowing the use of probability distributions
 in place of worst-case conditions. The description of these .models and their advantages and
 disadvantages is found in the 1991 Technical Support Document for Water Quality-based
 Toxic Control (TSD).

       Dynamic models have received increased attention in the last  few years as a result of
 the perception that static modeling is over-conservative due to environmentally conservative
 dilution assumptions.  This has led to the misconception that dynamic models will always
justify less stringent regulatory controls (e.g. NPDES effluent limits) than static models. In
 effluent dominated waters where the upstream concentrations are relatively constant,
 however, a dynamic model will calculate a more stringent wasteload allocation than will a
 steady state model.  The reason is that the critical low flow required  by many State water
 quality standards in effluent dominated streams occurs more frequently than once every three
 years. When other environmental factors (e.g. upstream pollutant concentrations) do not
 vary appreciably, then the overall return frequency of the steady state model may be greater
 than once in three years.  A dynamic modeling approach, on the other hand, would be more
 stringent, allowing only a once in three year return frequency.  As a result, EPA considers
 dynamic models to be a more accurate rather than a less stringent approach to implementing
 water quality criteria.

       The 1991 TSD provides recommendations on the use of steady state and dynamic
 water quality models.  The reliability of any modeling technique greatly depends on tile
 accuracy of the data used in the analysis. Therefore, the selection of a model also depends
 upon the data. EPA recommends that steady state wasteload allocation analyses generally be
 used where few or no whole effluent toxicity or specific chemical measurements are
 available, or where daily receiving water flow records are not available. Also, if staff
 resources are insufficient to use and defend the use of dynamic models, then steady state

-------
 models may be necessary.  If adequate receiving water flow and effluent concentration data
 are available to estimate frequency distributions, EPA recommends that one of the dynamic
 wasteload allocation modeling techniques be used to derive wasteload allocations which will
 more exactly maintain water quality standards. The minimum data required for input into
 dynamic models include at least 30 years of river flow data and one year of effluent and
 ambient pollutant concentrations.
 o     Dissolved-Total Metal Translators

       When water quality criteria are expressed as the dissolved form of a metal, there is a
 need to translate TMDLs and NPDES permits to and from the dissolved form of a metal to
 the total recoverable form. TMDLs for toxic metals must be able to calculate 1) the
 dissolved metal concentration in order to ascertain attainment of water quality standards and
 2) the total recoverable metal concentration in order to achieve mass balance.  In meeting
 these requirements, TMDLs consider metals to be conservative pollutants and quantified as
 total recoverable to pres^nre conservation of mass. The TMDL calculates the dissolved or
 ionic species of the met   based on factors such as total suspended solids (TSS) and ambient
 pH.  (These assumptions ignore the complicating factors of metals interactions with other
 metals.) In  addition, this approach assumes that ambient factors influencing metal
 partitioning remain constant with distance down the river. This assumption probably is
 under the low flow conditions typically used as design flows  for permitting of metals (e.g.,
 7Q10, 4B3,  etc) because erosion, resuspension, and wet weather loadings are unlikely to be
 significant and river chemistry is generally stable. In steady-state dilution modeling, metals
 releases may be assumed to remain fairly constant (concentrations exhibit low variability)
 with time.

      EPA-s NPDES  regulations require that metals limits in permits be stated as total
recoverable in most cases (see 40 CFR §122.4S(c)).  Exceptions occur when an effluent
guideline specifies the limitation in another form of the metal or the approved analytical
methods measure only  the dissolved form.  Also, the permit writer may express a metals
limit in another form (e.g., dissolved,  valent, or total) when required, in highly unusual
cases, to carry out the  provisions of the CWA.

      The preamble to the September 1984 National Pollutant Discharge Elimination System
Permit Regulations states that the total recoverable method measures dissolved metals plus
 that portion of solid metals that can easily dissolve under ambient conditions (see 49 EsdfflQl
 Register 38028, September 26,1984). This method is intended to measure metals in the
 effluent that are or may easily become environmentally active, while not measuring metals
 that are expected to settle out and remain inert

      The preamble cites, as an example, effluent from an electroplating facility that adds
 lime and uses clarifiers. This effluent will be a combination of solids not removed by t^fc
 clarifiers and residual dissolved metals.  When the effluent from the clarifien, usually wWa

-------
  high pH level, mixes with receiving water having significantly lower pH level, these solids
  instantly dissolve.  Measuring dissolved metals in the effluent, in this case, would
  underestimate the impact on the receiving water.  Measuring with the total metals method, on
  the other hand, would measure metals that would be expected to disperse or settle out and
  remain inert or be covered over.  Thus, measuring total recoverable metals in the effluent
  best approximates the amount of metal likely to produce water quality impacts.

        However, the NPDES rule does not require in any way that State water quality
 standards be in the total recoverable form; rather,  the rule requires permit writers to consider
 the translation between differing metal forms in the calculation of the permit limit so that a
 total recoverable limit can be established. Therefore, both the TMDL and NPDES uses of
 water quality criteria require the ability to translate from the dissolved form and the total
 recoverable form.

        Many toxic substances, including  metals, have a tendency to leave the dissolved phase
 and attach to suspended solids. The partitioning of toxics between solid and dissolved phases
 can be determined as a function of a pollutant-specific partition coefficient and the
 concentration of solids.  This function is  expressed by a linear partitioning equation:
                                                            where,
                           dissolved phase metal concentration,
                           total metal concentration,
                     TSS  «= total suspended solids concentration, and
                           partition coefficient.
       A key assumption of the linear partitioning equation is that the sorption reaction
reaches dynamic equilibrium at the point of application of the criteria; that is, after allowing
for initial mixing the partitioning of the pollutant between the adsorbed and dissolved forms
can be used at any location to predict the fraction of pollutant in each respective phase.

       Successful application of the linear'partitioning equation relies on the selection of the
partition coefficient. The use of a partition coefficient to represent the degree to which
toxics adsorb to solids is most readily applied to organic pollutants; .partition coefficients for
metals are more difficult to define. Metals typically exhibit more complex speciation and
complexation reactions than organics and the degree of partitioning can vary greatly
depending upon site-specific water chemistry. Estimated partition coefficients can be
determined for a number of metals, but waterbody or site-specific observations of dissolved
and adsorbed concentrations are preferred.

-------
                         EPA suggests three approaches for instances where a water quality criterion for a
                  metal is expressed in the dissolved form in a State's water quality standards:

                         1.   Using clean analytical techniques and field sampling procedures with appropriate
                         QA/QC, collect receiving water samples and determine site specific values of  K* for
                         each metal.  Use  these K« values to "translate" between total recoverable and
                         dissolved metals in  receiving water.  This approach is. more difficult to apply because
                         it relies upon the  availability of good quality measurements of ambient metal
                         concentrations. This approach provides an accurate assessment of the dissolved metal
                         fraction providing sufficient samples are collected. EPA's initial recommendation is
                         that at least four pairs of total recoverable and dissolved ambient metal measurements
                         be  made during low flow conditions or 20 pairs over all flow conditions.  EPA
                         suggests that the average of data collected during low flow or the 95th percentile
                         highest dissolved  fraction for all flows be used.  The low flow average provides a
                         representative picture of conditions during the rare low flow events. The 95th
                         percentile highest dissolved fraction for all flows provides a critical condition
                         approach analogous to the approach used to identify low flows and other critical
                         environmental  conditions.

                         2.  Calculate the total recoverable concentration for the purpose of setting the permit
                         limit. Use a value of 1  unless the permittee has collected data (see til above) to show
                         that a different ratio should be used.  The value of 1 is conservative and will not err
                         on  the side of violating standards. This approach  is very simple to apply because it
                         places the entire burden  of data collection and analysis solely upon permitted
                         facilities. In terms of technical merit, it has the same characteristics of the previous
                         approach. However, permitting authorities may be faced with difficulties in
                         negotiating with facilities on the amount of data necessary to determine the ratio and
                         the necessary quality control methods to assure that the ambient data are reliable.

                         3.  Use the historical data on total suspended solids (TSS) in receiving waterbodies  at
                         appropriate design flows and K* values presented in the Technical Guidance Manual
                         for Performing Waste Load Allocations. Book U.  Streams and Rivers.  EPA-440/4-
                         84-020 (1984) to •translate" between (total recoverable) permits limits and dissolved
                         metals in receiving water. This approach is fairly simple to apply. However, these
                         K«  values are-suspect due .to possible quality assurance problems with the data used to
                         develop  the values.  EPA's initial analysis of this approach and these values in one
                         site indicates that  these K« values generally over-estimate the dissolved fraction of
                         metals in ambient waters (see Figures following).  Therefore, although this approach
                         may not provide an accurate estimate of the dissolved fraction, the bias in the estimate
                         is likely to be a conservative one.

                         EPA suggests that regulatory authorities use approaches i 1 and S2 where States
                  express their water quality  standards in the dissolved form. In those States where the
                  standards  are in the total recoverable or acid soluble form, EPA recommends that no
/ s*

-------

approach #1.

-------
            M«Mtir«d vs.  -odeled  Dissolved Copper  Concentrations
3.5 T

 3

25

 2

15

 1

0.5

 0
                                                      —•— Modeled
                                                      --u-  Measured
                •4-
                    10
IS
 20       25
Sampling Station
30
	1-
  35
40      45

-------
v«. Hod*lad  Diaaolvtd  CadaUtui  Concentrations
               20       25
             Sampling Station
                                                                  Modeled
                                                                  Measured

-------
                      I
Measured vs.  Modeled  Dissolved  Lead Concentrations
       10
15       20      25
       Sampling Station
30
35
40
                                                                           Modeled
                                                                      —ll   Measured
 I
45

-------
                                      j
              M«a»ur«d v».  Mod*lad Diaaolvad  Mercury  Concentrations
  0.12 T
   o.i 4
  0.08
B, 006
3
  0.04
  0.02
                       10       15       20      25

                                       Sampling Station
30
                              -  »-  Modeled

                             -  n   Measured
35
40
45

-------
Dis«olv«d Hlckal concentrations
                                                  -•-  Modeled
                                                  -t>— Measured
 Sampling Station

-------
                                                        ATTACHMENT #4
                              GUIDANCE DOCUMENT
           ON CLEAN ANALYTICAL TECHNIQUES AND MONITORING
                                    October 1993
Guidance on Monitoring

o   Use of Clean Sampling and Analytical Techniques

     Appendix B to the WER guidance document (attached) provides some general guidance
on the use of clean techniques.  The Office of Water recommends that this guidance be used
by States and Regions as an interim step while the Office of Water prepares more detailed
guidance.


o      Use of Historical DMR Data

       With respect to effluent or ambient monitoring data reported by an NPDES permittee
on a Discharge Monitoring Report (DMR), the certification requirements place the burden on
the permittee for collecting and reporting quality data.  The certification regulatipn at 40
CFR 122.22(d) requires permittees, when submitting information, to state: "I certify under
penalty of law that this document and all attachments were prepared  under my direction or
supervision in accordance with a system designed to assure that qualified personnel properly
gather  and evaluate the information submitted. Based  on my inquiry of the person or persons
who manage the system, or those persons directly responsible for gathering the information,
the information submitted is, to the best of my knowledge and belief, true, accurate, and
complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fine and imprisonment for knowing violations."

       Permitting authorities should continue to consider the information  reported in DMRs
to be true, accurate, and complete as certified by the permittee.  Under 40 CFR 122.41(0(8),
however, as soon as the permittee becomes aware of new information specific to the effluent
discharge that calls into question the accuracy of the DMR data, the permittee must submit
such information to the permitting authority. Examples of such information include a new
rinding that the reagents used in the laboratory analysis are contaminated  with trace levels of
metals, or a new study that the sampling equipment imparts trace metal contamination.  This
information must be specific to the discharge and based on actual measurements rather than
extrapolations from reports from other facilities. Where a permittee submits information

-------
       In addition to submitting the information described above, the permittee also must
develop procedures to assure the collection and analysis of quality data that are true,
accurate, and complete.  For .example, the permittee may submit a revised quality assurance
plan that describes the specific procedures to be undertaken to reduce or eliminate trace
metal contamination.

-------
M.a»ur.d vs. Micelea Dissolved  Zlno Concentrations
         25
Sampling Station.
                                        30
                                                35
                                                                          Modeled
                                                                          Measured
                                                                45

-------
           Maaaurad vs.  Mo4alad Diaaolvad Araanio Concentrations
25
0.5
 A
if  ^
                                 \
                                             1	\-
                    10
        20      25

      Sampling Stilton
30      35
                                                                                    •••-•  Modeled

                                                                                    1'    Measured
40
 I

45

-------
                                                        10-1-93
 Appendix B.  Guidance concerning tbe Use of "Clean Techniques" and
             QA/QC in the Measurement of Trace Metals


 Recent information (ShiHer and Boyle 1987; Hindom et al.  1991)
 has raised questions concerning the quality of reported
 concentrations  of trace metals in both fresh and salt (estuarine
 and marine)  surface waters.   A lack of awareness of true ambient
 concentrations  of metals in saltwater and freshwater systems can
 be  both a cause and a result of the problem.   The ranges of
 dissolved metals that are typical in surface waters of the United
 States away  from the immediate influence of discharges (Bruland
 1983;  Shiller and Boyle 1985,1987;  Trefry et al.  1986;  Windom et
 al.  1991) are:

           Metal        Salt water           Fresh water
          	        fuo/Ll               fuo/Ll
          Cadmium     0.01  to   0.2         0.002 to 0.08
          Copper      0.1   to   3.          0.4   to 4.
          Lead        0.01  to   1.          0.01  to 0.19
          Nickel      0.3   to   5.          1.    to 2.
          Silver      O.OOS to   0.2
          Zinc        0.1   to 15.          0.03  to 5.

The U.S. EPA (1983,1991) has published analytical methods for
monitoring metals in waters and wastewaters, but these methods
are inadequate for determination of ambient concentrations of
some metals in some surface waters.  Accurate and precise
measurement of these low concentrations requires appropriate
attention to seven areas:
1. Use of_"clean techniques" during collecting, handling,
   storing, preparing, and analyzing samples to avoid
   contamination.
2. Use of analytical methods that have sufficiently low detection
   limits.
3. Avoidance of interference in the quantification (instrumental
   analysis) step.
4. Use of blanks to assess contamination.
5; Use of matrix spikes (sample spikes) and certified reference
   materials (CBMs) to assess interference  and contamination.
6. Use of replicates to assess precision.
7. Use of certified-standards.
In a strict sense, the term "clean techniques" refers to
techniques that reduce contamination and enable the accurate and
precise measurement of trace metals in fresh and salt surface
waters.  In a broader sense, the tern also  refers to related
issues concerning detection limits, quality control, and quality
assurance.  Documenting data quality demonstrates the amount of
confidence that can be placed in the data,  whereas increasing the
sensitivity of methods reduce the problem of deciding how to

-------
 interpret results that are reported to be below detection limits

 This appendix.is written for those analytical laboratories that
 want guidance concerning ways to lower detection limits,  increase
 precision,  and/or increase accuracy.   The ways to achieve these
 goals are to increase the sensitivity of the analytical methods,
 decrease contamination,  and decrease interference.   Ideally,
 validation of a procedure for measuring concentrations of metals
 in  surface water requires demonstration that agreement can be
 obtained using completely different procedures beginning  with the
 sampling step and continuing through  the quantification step
 (Bruland et al.  1979), but few laboratories  have the resources to
 compare  two different procedures.   Laboratories can,  however, (a)
 use  techniques  that  others have found useful for improving
 detection limits,  accuracy,  and precision, and (b) document data
 quality  through use  of blanks,  spikes,  CRMs,  replicates,  and
 standards.

 In general,  in  order to  achieve accurate and precise  measurement
 of a  particular  concentration,  both the detection limit and the
 blanks should be less than one-tenth  of that concentration.
 Therefore,  the term  "metal-free" can  be interpreted to mean that
 the total amount of  contamination that occurs during  sample
 collection  and processing (e.g., from gloves,  sample  containers,
 labware,  sampling apparatus,  cleaning solutions,  air,  reagents,
 etc.) is  sufficiently low that  blanks are less than one-tenth a
 the lowest  concentration that needs to be measured.            '

Atmospheric particulates can  be a major source of contamination
 (Moody 1982;  Adeloju and Bond 1985).  The term "class-100" refers
 to a  specification concerning the amount of particulates  in air
 (Moody 1982); although the specification says  nothing  about the
 composition of the particulates, generic control of particulates
 can greatly reduce trace-metal  blanks.   Except during  collection
 of samples  and initial cleaning of  equipment,  all handling of
 samples,  sample  containers,  labware,  and sampling apparatus
 should be performed  in a class-100  bench, room, or glove  box.

 Nothing  contained or not contained  in this appendix adds  to or
 subtracts from any regulatory requirements set fprth  in other EPA
 documents concerning metal analyses.   The word "must**  is  used in
 this  appendix merely to  indicate items that  are considered very
 important by analytical  chemists who  have worked to increase
 accuracy and precision and lower detection limits in  trace-metal
 analysis.   Some  items are considered  important because they have
 been  found  to have received inadequate attention in some
 laboratories performing  trace-metal analyses.

 Two topics  that are  not  addressed in  this appendix are:
 1. The "ultraclean techniques"  that are likely to be  necessary
   when  trace analyses of mercury are performed.
 2. Safety in analytical  laboratories.

-------
 Other documents should be consulted if these topics are of
, concern.

 Avoiding contamination bv use of "clean techniques^1

 Measurement of trace metals in receiving waters must take into
 account the potential for contamination during each step in the
 process.  Regardless of the specific procedures used for
 collection,  handling/  storage,  preparation (digestion,
 filtration,  and/or extraction),  and quantification  (instrumental
analysis),  the general principles of contamination  control must
be applied.  Some  specific recommendations are:
a. Non-talc latex  or class-100 polyethylene gloves  must  be worn
   during all  steps  from  sample  collection to  analysis.   (Talc
   seems to  be a particular problem with  zinc; gloves made with
   talc  cannot be  decontaminated sufficiently.)  Gloves  should
   only  contact surfaces  that are metal-free; gloves should be
   changed  if  even suspected of  contamination.
b. The acid  used to  acidify samples  for preservation and
   digestion and to  acidify water for final cleaning of  labware,
   sampling  apparatus, and  sample containers must be metal-free.
   The quality of  the acid  used  should be better than reagent-
   grade.  Each lot  of acid must be analyzed for the metal(s)  of
   interest  before use.
c. The water used  to prepare acidic cleaning solutions and  to
   rinse labware,  sample containers, and sampling apparatus may
   be prepared by  distillation, deionization, or reverse osmosis,
   and must  be demonstrated to be metal-free.
d. The work  area,  including bench tops and hoods, should be
   cleaned  (e.g., washed and wiped dry with lint-free, class-100
   wipes) frequently to remove contamination.
e. All handling of samples  in the laboratory, including filtering
   and analysis, must be performed in a class-100 clean bench or
   a glove box  fed by particle-free air or nitrogen; ideally the
   clean bench or glove box should be located within a class-100
   clean room.
f. Labware,  reagents, sampling apparatus, and sample containers
   must  never be left open to the atmosphere; they should be
   stored in a class-100 bench, covered with plastic wrap, stored
   in a plastic box, or turned upside down on a clean surface.
   Minimizing the time between cleaning and using will help
   minimize  contamination.           '
g. Separata  sets of sample containers, labware, and sampling
   apparatus should be dedicated for different kinds of samples,
   e.g., receiving water samples, affluent samples,  etc.
h. To avoid  contamination of clean rooms, samples that contain
   very high concentrations of metals and do not require use of
   "clean techniques" should not be brought into clean rooms.
i. Acid-cleaned plastic, such as high-density polyethylene
   (HOPE), low-density polyethylene  (LDPE), or a f luoroplastic,
   must be the  only material that ever contacts a sample, except
   possibly  during digestion for the total recoverable
                                                               -.-7

-------
 measurement.   (Total recoverable  samples can be 'digested in
 some plast.ic  containers.)   Even HOPE and LDPE might not be
 acceptable  for mercury,  however.
 All  labware,  sample containers, and  sampling apparatus must be
 acid-cleaned  before use  or  reuse.
 1. Sample containers,  sampling apparatus,  tubing, membrane
   filters, filter  assemblies, and other labvare must be
   soaked in  acid until  metal-free.   The amount of  cleaning
   necessary  might  depend on the amount  of contamination and
   the length of time  the item will  be in contact with
   samples.   For example, if an acidified sample will be
   stored in  a sample  container for  three  weeks, ideally the
   container  should have been soaked in an acidified  metal-
   free solution for at least three weeks.
2. It might be desirable to perform  initial cleaning,  for
   which reagent-grade acid may be used, before the items are
   allowed into a clean room.  For most metals, items  should
   be either  (a) soaked in 10 percent concentrated nitric acid
   at 50°C for at least one hour,  or  (b) soaked in SO percent
   concentrated nitric acid at room temperature for at least
   two days; for arsenic and mercury, soaking for up to two
   weeks at 50«C in 10 percent concentrated nitric acid might
   be required.  For plastics that might be damaged by strong
   nitric acid, such as polycarbonate and possibly HOPE and
   LDPE,  soaking in 10 percent concentrated hydrochloric acicW
   either in place of or before soaking in a nitric acid
   solution, might be desirable.
3. Chromic acid must not be used to clean items that will be
   used in analysis of metals.
4. Final soaking and cleaning of sample containers,  labware,
   and sampling apparatus must be  performed in a class-100
   clean room using metal-free acid and water.  The solution
   in an acid bath must be analyzed periodically to
   demonstrate that it is metal-free.
5. After labware and sampling apparatus are cleaned, they may
   be stored in a clean room in a  weak acid bath prepared
   using metal-free acid and water.   Before use, the items
   should be rinsed at least three times vith metal-free
   water.  After the final rinse,  the items should be moved
   immediately, with the open end  pointed down, to a class-100.
   clean bench.  Items may be dried on a class-100 clean
   bench; items must not be dried  in an oven or with
   laboratory towels.  The sampling apparatus should be
   assembled in-a class-100 clean  room or bench and double-
   bagged in metal-free polyethylene zip-type bags for
   transport to the field; new bags are usually metal-free.
6. After sample containers are cleaned, they should be filled
   with metal-free water that has  been acidified to a pH of 2
   with metal-free nitric acid (about 0.5 mL per liter) for
   storage until use.  At the time of sample collection, the
   sample containers should be emptied and rinsed at least -
   twice with  the solution being sampled before the actual

-------
    nickel, and zinc (Bruland et al. 1979; Nriagu et al.  1993).
 b.  The detection limit should be .less than ten percent of  the
    lowest concentration that is to be measured.

 Avoiding interferences

 a.  Potential interferences must be assessed for the specific
    instrumental analysis technique used and each metal to  be
    measured.
 b.  If  direct analysis  is used,  the salt present in  high-salinity
    saltwater samples is likely  to cause interference in most
    instrumental techniques.
 c.  As  stated above,  extraction  of the metal  from the sample  is
    particularly useful because  it simultaneously concentrates the
    metal and  eliminates potential matrix interferences.
Using blanks to  assess contamination

a. A laboratory  (procedural, method) blank consists of filling a
   sample container with analyzed metal-free water and processing
   (filtering, acidifying, etc.) the water through the laboratory
   procedure in  exactly the same way as a sample.  A laboratory
   blank must be included in each set of ten or fewer samples to
   check for contamination in the laboratory, and must contain
   less than ten percent of the lowest concentration that is to
   be measured.   Separate laboratory blanks must be processed for
   the total recoverable and dissolved measurements, if both
   measurements  are performed.
b. A field (trip) blank consists of filling a sample container
   with analyzed metal-free water in the laboratory, taking the
   container to  the site, processing the water through tubing,
   filter, etc.,  collecting the water in a sample container, and
   acidifying the water the same as a field sample.  A field
   blank must be processed for each sampling trip.  Separate
   field blanks  must be processed for the total recoverable
   measurement and for the dissolved measurement, if filtrations
   are performed at the site.  Field blanks vast be processed in
   the laboratory the same as laboratory blanks.
Assessing accuracy

a. A calibration curve must be determined for each analytical run
   and the calibration should be checked about every tenth
   sample.  Calibration solutions must be traceable back to a
   certified standard from the U.S. EPA or the National Institute
   of Science and Technology (HIST).
b. A blind standard or a blind calibration solution must be
   included in each group of about twenty samples.

-------
       sample.is placed in the sample container.
 k. Field samples must be collected in a manner that eliminates
    the potential for contamination from the sampling platform,
    probes, etc.  Exhaust from boats and the direction of wind and
    water currents should be taken into account.  The people who
    collect the samples must be specifically trained on how to
    collect field samples.  After collection, all handling of
    samples in the field that will expose the sample to air must
    be performed in a portable class-100 clean bench or glove box.
 1. Samples must be acidified (after filtration if dissolved metal
    is to be measured)  to a pH of less than 2,  except that the pH
    must be less than 1 for mercury.   Acidification should be done
    in a clean room or bench,  and so it might be desirable to wait
    and acidify  samples in a laboratory rather  than in the field.
    If samples are acidified in the field,  metal-free acid can be
    transported  in plastic bottles and poured into a plastic
    container from which acid can be removed and added to  samples
    using plastic pipettes.   Alternatively,  plastic automatic
    dispensers can be used.
B.  Such  things  as probes  and thermometers  must not be put in
    samples  that are  to be analyzed for metals.   In particular, pH
    electrodes and mercury-in-glass thermometers must not  be used
    if mercury is, to  be measured.   If pH is  measured,  it must be
    done  on  a  separate aliquot.
n.  Sample handling should be minimized.  For example,  instead of
    pouring  a  sample  into a graduated cylinder to measure the
    volume,  the  sample can be weighed after  being poured into a
    tared container;  alternatively, the container from which the
    sample is  poured  can be weighed.  (For saltwater samples,  the
    salinity or density should be taken into account when weight
    is converted to volume.)
o. Each reagent used must be verified to be metal-free.  If
   metal^free reagents are not commercially available, removal of
   metals will probably be necessary.
p. For the total recoverable measurement, samples should be
   digested in a class-100 bench, not in a metallic hood.  If
   feasible, digestion should be done in the sample container by
   acidification and heating.
q. The longer the time between collection and analysis of
   samples, the greater the chance of contamination, loss, etc.
r. Samples must be stored in the dark, preferably between 0 and
   4°C with no air space in the sample container.
Achieving low detection limits

a. Extraction of the metal from the sample can be extremely
   useful if it simultaneously concentrates the metal, and
   eliminates potential matrix interferences.  For example,
   ammonium 1-pyrrolidinedithiocarbamate and/or diethylanmonium
   diethyldithiocarbamate can extract cadmium, copper, lead,

-------
             .nickel, and zinc  (Bruland et al. 1979; Nriagu et al.  1993).
           b-X.The.detectipn limit should be less than ten percent of the
                     concentration that is to be measured.
           A Voiding interferences
                ;'• j ' : . •.•
           a,  potential interferences must be assessed for the specific
              instrumental analysis technique used and each metal to be
              measured.
           b.  If. direct analysis is used, the salt present in high-salinity
              saltwater samples is likely to cause interference in most
              instrumental -techniques.
           c.  As  stated above, extraction of the metal from the sample  is
            -  particularly useful because it simultaneously concentrates the
            :  metal and eliminates potential matrix interferences.
          Usino  blanks to assess contamination

          a. A laboratory (procedural,  method)  blank consists of filling a
            . sample container with analyzed metal-free water and processing
             .(filtering,  acidifying,  etc.)  the water through the laboratory
             procedure in exactly the same  way as a  sample.  A laboratory
             blank  must be included in each set of ten or  fewer samples to
             check  for contamination in the laboratory, and must contain
             less than ten percent of the lowest concentration that is to
             be  measured.   Separate laboratory blanks must be processed for
             the total recoverable and dissolved measurements, if both
             measurements are performed.
          b. A field (trip)  blank consists  of  filling a sample container
            ' with analyzed metal-free water in the laboratory, taking the
             container to the site, processing the water through tubing,
             filter,  etc.,  collecting the water in a sample container, and
             acidifying the water the same  as  a field sample.  A field
             blank  must be processed  for each  sampling trip.  Separate
             field  blanks must be processed for the  total  recoverable
             measurement and for the  dissolved measurement, if filtrations
             are. performed at the site.   Field blanks must be processed in
             the laboratory the same  as laboratory blanks.
          Assessing  accuracy

          a. A calibration curve must be determined  for each analytical run
             and -the calibration should be checked about  every tenth
             sample.   Calibration solutions must be  traceable back to a
             certified standard from the U.S.  EPA or the  National Institute
             of Science and Technology (MIST).
          b. A blind standard or a blind calibration solution must be
             included in each group of about twenty  samples.
202

-------
 c. At least'one of .the following must be included in each group
    of about twenty samples:
    1. A matrix spike (spiked sample;  the method of known
       additions).
    2. A CRM, if one is available in a matrix that closely
       approximates that of the samples.   Values obtained for the
       CRM must be  within the published values.
 The concentrations in blind standards and solutions,  spikes, and
 CRMs must not be more than 5 times  the median concentration
 expected to be present in the samples.
 Assessing  precision

 a.  A sampling replicate must be included with each  set of  samples
    collected at each sampling location.
 b.  If the  volume of the sample is large enough, replicate
    analysis of at least one sample must be performed along with
    each group of about ten samples.
Special considerations concerning the dissolved measurement

Whereas the total recoverable measurement is especially subject
to contamination during the digestion step, the dissolved
measurement is subject to both loss and contamination during the
filtration step.
a. Filtrations must be performed using acid-cleaned plastic
   filter holders and acid-cleaned membrane filters.  Samples
   must not be filtered through glass fiber filters, even if the
   filters have been cleaned with acid.  If positive-pressure
   filtration is used, the air or gas must be passed through a
   Q.2-um in-line filter; if vacuum filtration is used, it must
   be performed on a class-100 bench.
b. Plastic filter holders must be rinsed and/or dipped between
   fNitrations, but they do not have to be soaked between
   filtrations if all the samples contain about the same
   concentrations of metal.  It is best to filter samples from
   low to high concentrations.  A membrane filter must not be
   used for more than one filtration.  After each filtration, the
   membrane filter-must-be removed and discarded, and the filter
   holder must be either rinsed with metal-free water or dilute
   acid and dipped in a metal-free acid bath or rinsed at least
   twice with metal-free dilute acid; finally, the filter holder
   must be rinsed at least twice with metal-free water.
c. For each sample to be filtered, the filter holder and membrane
   filter must be conditioned with the sample, i.e., an initial
   portion of the sample must be filtered and discarded.

The accuracy and precision of the dissolved measurement should be

-------
            assessed periodically.  A large volume of a buffered solution   {
            (such as aerated 0.05 N sodium bicarbonate) should be spiked so
            that the concentration of the metal of interest is in the range
            of the low concentrations that are to be measured.  The total
            recoverable concentration and the dissolved concentration of the
            metal in the spiked buffered solution should be measured
            alternately until each measurement has been performed at least
            ten times.  The means and standard deviations for the two
            measurements should be the same.   All values deleted as outliers
            aust be acknowledged.
            Reporting results

            To indicate the quality of the data,  reports of results of
            measurements of the concentrations of metals must include a
            description of the blanks, spikes, CPMs,  replicates,  and
            standards that were run, the number run,  and the results
            obtained.   All values deleted as outliers must be acknowledged.
            Additional information

            The items presented above are  some  of the important aspects of
            "clean techniques"; some aspects of quality assurance and qua
            control are also presented.  This is not a definitive treatmen
            of these topics; additional  information  that might be useful is
            available in such publications as Patterson and  Settle (1976) ,
            Zief and Mitchell (1976),  Bruland et al.  (1979), Moody and Beary
            (1982),  Moody (1982),  Bruland  (1983),  Adeloju and  Bond (1985),
            Barman and Yeats (1985),  Byrd  and Andreae (1986),  Taylor (1987),
            Sakamoto-Arnold (1987),  Tramontane  et al.  (1987),  Puls and
            Barcelona (1989),  Windom et  al. (1991),  U.S. EPA (1992),  Horowitz
            et al.  (1992),  and Nriagu et al. (1993).
            References

            Adeloju,  S.B.,  and A.M.  Bond.   1985.   Influence of Laboratory
            Environment on  the Precision and Accuracy of Trace Element
            Analysis.   Anal.  Chem.  57:1728-1733.

            Berman,  S.S., and P.A.  Yeats.   1985.   Sampling of Seawater for
            Trace Metals.   CRC Reviews in Analytical Chemistry 16:1-14.

            Bruland,  K.W.,  R.p. Franks,  G.A. Knauer,  and J.H. Martin.   1979.
            Sampling and Analytical Methods for the Determination of Copper,
            Cadmium,  Zinc,  and Nickel at the Kanogram per Liter Level  in Sea
            Water.  Anal. Chim. Acta 105:233-245.

                                            8
o c

-------
' Bruland, K.W.  1983.  Trace  Elements in Sea-water.  In: Chemical
 Oceanography, Vol. 8.  J.P.  Riley and R. Chester, eds.  Academic
 Press, New York, NY.  pp.  157-220.

 Byrd, J.T., and M.O. Andreae.  1986.  Dissolved and Particulate
 Tin in North Atlantic Seawater.  Marine Chemistry 19:193-200.

 Horowitz,  A.J.,  K.A. Elrick, and M.R. Colberg.  1992.   The Effect
 of Membrane Filtration Artifacts on Dissolved Trace Element
 Concentrations.   Water Res.  26:753-763.

Moody,  J.R.   1982.   NBS Clean Laboratories for Trace Element
Analysis.   Anal.  Chem.  54:1358A-1376A.

Moody,  J.R.,  and E.S.  Beary.   1982.   Purified Reagents for Trace
Metal Analysis.   Talanta 29:1003-1010.

Nriagu,  J.O.,  G.  Lawson,  H.K.T.  Hong, and J.M. Azcue.   1993.  A
Protocol for  Minimizing Contamination in the Analysis  of Trace
Metals  in  Great  Lakes Waters.  J.  Great Lakes Res.  19:175-182.

Patterson, C.C.,  and D.M.  Settle.   1976.   The Reduction in Orders
of Magnitude  Errors  in  Lead Analysis of Biological Materials and
Natural  Waters by Evaluating and Controlling the  Extent and
Sources  of Industrial Lead Contamination Introduced during Sample
Collection and Processing.   In: Accuracy in Trace Analysis:
Sampling, Sample  Handling,  Analysis.  P.D.  LaFleur, ed.  National
Bureau of Standards Spec.  Publ. 422, U.S. Government Printing
Office, Washington, DC.

Puls, R.W., and M.J. Barcelona.  1989.  Ground Water Sampling for
Metals Analyses.  EPA/540/4-89/001.  National Technical
Information Service, Springfield, VA.

Sakamoto-Arnold,  C.M., A.K. Hanson,  Jr., D.L.  Huizenga,  and' D.R.
Kester.  1987.  Spatial and Temporal Variability  of Cadmium  in
Gulf Stream Warm-core Rings and Associated  Waters.  J. Mar.  Res.
45:201-230.

Shiller, A.M., and E. Boyle.   1985.  Dissolved Zinc in Rivers.
Nature 317:49-52.

Shiller, A.M., and E.A. Boyle.  1987.  Variability of Dissolved
Trace Metals in the. Mississippi River.  Geochim. Cosmochim.  Acta
51:3273-3277.

Taylor, J.K.  1987.  Quality  Assurance of Chemical Measurements.
Lewis Publishers, Chelsea,  MI.

Tramontane, J.M., J.R. Scudlark, and T.M. Church.  1987.  A
Method for the Collection,  Handling, and Analysis of Trace Metals
in Precipitation.  Environ. Sci. Technol. 21:749-753.

-------
 Trefry, J.H., T.A. Nelsen, R.P. Trocine, S. Metz., and T.w.
 Vetter.  1986.  Rapp. P.-v. Reun. Cons. int. Explor.  Her.
 186^277-288.

 U.S.  Environmental Protection Agency.  1983.  Methods for
 Chemical Analysis of Water and Wastes.  EPA-600/4-79-020.
 National Technical Information Service, Springfield,  VA.
 Sections 4.1.1,  4.1.3, and 4.1.4

 U.S.  Environmental Protection Agency.  1991.  Methods for  the
 Determination of Metals in Environmental Samples.   EPA-600/4-91-
 010.   National Technical Information Service,  Springfield, VA.

 U.S.  Environmental Protection Agency.  1992.  Evaluation of
 Trace-Metal  Levels in Ambient Waters and Tributaries  to New
 York/New Jersey  Harbor for Waste Load Allocation.   Prepared by
 Battelle Ocean Sciences under Contract No.  68-C8-0105.  -

 Windom,  H.L.,  J.T. Byrd,  R.G.  Smith, and F.  Huan.   1991.
 Inadequacy of  NASQAN Data for Assessing Metals Trends in the
 Nation's Rivers.   Environ.  Sci.  Technol.  25:1137-1142.  (Also see
 Comment  and  Response,  Vol.  25,  p.  1940.)

 Zief, M., and  J.W. Mitchell.   1976.   Contamination Control in
Trace Element  Analysis.   Chemical  Analysis Series,  Vol. 47.
Wiley, New York, NY.
                                10

-------