NATIONAL WATER QUALITY LABORATORY
TECHNICAL MEMORANDUM 97-02
----RESPONSE REQUESTED BY JANUARY 1, 1997----
November 25, 1996
To: Water Resources Division
From: Peter F. Rogerson, Chief
National Water Quality Laboratory
Branch of Analytical Services
Subject: Proposed Replacement or Elimination of NWQL Procedures
Authors: Peter F. Rogerson, Chief, NWQL, (303)467-8003 (rogerson)
Revision: None
BACKGROUND
In the interests of efficiency and economy, the National Water Quality
Laboratory (NWQL) has reviewed all analytical tests performed at the NWQL
to determine which procedures could be eliminated, replaced, or contracted
to increase efficiency and save money for our customers. Within this
Technical Memorandum are proposals to replace or eliminate several NWQL
analytical procedures. This proposed action is not final. Over the next
30 days, please examine these proposed changes for impact on your ongoing
projects. If you find that these changes are unacceptable, please let me
know so that the NWQL can work with you to minimize the impact or to
maintain a critical procedure. Following the 30-day comment period, the
NWQL will issue a technical memorandum with an effective date for the
changes. Although I believe there will be no unacceptable changes in data
quality, I am encouraging all NWQL customers to verify this lack of
significant impact prior to implementing the proposed procedure.
Thank you for working with us to provide the best possible analytical
service at the lowest possible price.
SCOPE
The Inorganic Chemistry Program used the following criteria to set
priorities for analytical tests that could be eliminated, replaced, or
contracted:
1. Small numbers of submitted samples.
2. Small numbers of customers submitting samples.
3. Availability of similar tests from NWQL or other sources such as
contract labs.
4. Analytical procedures that are particularly difficult to set up.
5. Analytical procedures on which the NWQL appears to be losing money.
The NWQL proposes to eliminate the following Low-Level [Low-Ionic Strength
(LIS)] tests and replace them with the equivalent regular level tests:
[LIS, low-ionic strength; GFAA, graphite furnace atomic absorption;
ICP/MS, inductively coupled plasma/mass spectrometry; DCP, direct-
current plasma; ICP, inductively coupled plasma; AA, atomic absorption]
NAME LAB CODE* PARAMETER REPLACE WITH LAB CODE
CODE (PARAM. CODE)
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Acidity, LIS 1266 71825 B Acidity, Regular 1 (71825 A)
Alkalinity, LIS 1270 90410 B Alkalinity, Regular 70 (90410 A)
Manganese, LIS, 1257 01056 D Manganese, ICP/MS 1793 (01056 G)
GFAA
Nickel, LIS, GFAA 1256 01065 D Nickel, GFAA or 1562 (01065 F) or
ICP/MS 1795 (01065 G)
Cobalt, LIS, GFAA 1252 01035 E Cobalt, GFAA or 1556 (01035 F) or
ICP/MS 1890 (01035 G)
Cadmium, LIS, GFAA 1250 01025 E Cadmium, GFAA or 1554 (01025 F) or
ICP/MS 1788 (01025 G)
Lead, LIS, GFAA 1254 01049 E Lead, GFAA or 1560 (01049 F) or
ICP/MS 1792 (01049 G)
Copper, LIS, GFAA 1253 01040 E Copper, GFAA or 1558 (01040 F) or
ICP/MS 1791 (01040 G)
Chromium, LIS, GFAA 1251 01030 D Chromium, GFAA or 1936 (01030 I) or
ICP/MS 1789 (01030 G)
Zinc, LIS, GFAA 1276 01090 D Zinc, ICP or ICP/MS 671 (01090 B) or
1798 (01090 G)
Aluminum, LIS, DCP 1267 01106 D Aluminum, ICP or 2111 (01106 F) or
ICP/MS 1784 (01106 G)
Calcium, LIS, ICP 1273 00915 B Calcium, ICP 659 (00915 D)
Magnesium, LIS, AA 832 00925 A Magnesium, ICP 663 (00925 C)
Magnesium, LIS, ICP 1274 00925 D Magnesium, ICP 663 (00925 C)
Sodium, LIS, AA 834 00930 A Sodium, ICP 675 (00930 C)
Sodium, LIS, ICP 1276 00930 D Sodium, ICP 675 (00930 C)
Potassium, LIS, AA 0833 00935 A Potassium, AA 54 (00935 B)
*The lab codes for the eliminated tests will become invalid.
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Volatile Dissolved Solids will be eliminated because there have been no
requests for this test in over a year. There are insufficient requests to
justify maintaining the Volatile Bottom Material Solids test; therefore, it
will be offered only as a custom method and priced according to the cost of
setup and analysis. NWQL analyzed only 60 samples for total Nitrogen by
Antek during 1994. In contrast, many thousands of samples were analyzed by
Kjeldahl Nitrogen, on both filtered and unfiltered water. Therefore, NWQL
plans to discontinue total Nitrogen by Antek and only offer Kjeldahl
Nitrogen. The following three tests will be eliminated:
[ROE, residue on evaporation; diss., dissolved; Vol., volatile; Btm.,
bottom; TKN, Total Kjeldahl Nitrogen]
NAME LAB CODE* PARAMETER REPLACE WITH LAB CODE
CODE (PARAM. CODE)
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Solids, ROE, 229 00520 A Delete. No Requests. -
Volatile, Diss.
Solids, Vol., 516 00496 A Custom Analysis Only -
Btm. Material
Nitrogen, Antek 1570 00602 C Nitrogen, TKN 1688 (00625 C)
*The lab codes for the eliminated tests will become invalid.
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The following individual elemental determinations by atomic absorption
(AA) have already been replaced by more efficient multielement inductively
coupled plasma (ICP) techniques as announced in NWQL Technical Memorandum
96.04, effective April 1, 1996:
[ICP, inductively coupled plasma; AA, atomic absorption;
mg/L, milligram/Liter]
NAME LAB CODE* PARAMETER REPLACE WITH LAB CODE
CODE (PARAM. CODE)
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Barium, 7 01005 B Barium, 641 (01005 C)
Filtered Water, AA Filtered Water, ICP
Beryllium, 170 01010 A Beryllium, 655 (01010 B)
Filtered Water, AA Filtered Water, ICP
Cadmium, 126 01025 A Cadmium, 673 (01025 D)
Filtered Water, AA Filtered Water, ICP
Calcium, 12 00915 C Calcium, 659 (00915 D)
Filtered Water AA Filtered Water, ICP
Cobalt, 148 01035 A Cobalt, 644 (01035 C)
Filtered Water, AA Filtered Water, ICP
Copper, 151 01040 A Copper, 657 (01040 C)
Filtered Water, AA Filtered Water, ICP
Iron, 172 01046 C Iron, 645 (01046 D)
Filtered Water, AA Filtered Water, ICP
Lead, 191 01049 A Lead, 646 (01049 C)
Filtered Water, AA Filtered Water, ICP
Lithium, 39 01130 A Lithium, 664 (01130 B)
Filtered Water, AA Filtered Water, ICP
Magnesium, 40 00925 B Magnesium, 663 (00925 C)
Filtered Water, AA Filtered Water, ICP
Manganese, 42 01056 A Manganese, 648 (01056 C)
Filtered Water, AA Filtered Water, ICP
Nickel, 197 01065 A Nickel, 721 (01065 E)
Filtered Water, AA Filtered Water, ICP
Sodium, 59 00930 B Sodium, 675 (00930 C)
Filtered Water, AA Filtered Water, ICP¹
Strontium, 62 01080 A Strontium, 652 (01080 B)
Filtered Water, AA Filtered Water, ICP
Zinc, 67 01090 A Zinc, 671 (01090 B)
Filtered Water, AA Filtered Water, ICP
*The lab codes for the replaced tests will become invalid.
¹Sodium by ICP is less sensitive than Sodium by AA (detection limits of
0.2 vs. 0.1 mg/L)
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The NWQL has replaced the Direct Current Plasma (DCP) atomic emission
spectrometric determination of Aluminum (Al) and Boron (B) in filtered
water with an ICP determination as specified in NWQL Technical Memorandum
96.10. The DCP lab codes for Al and B will become invalid.
The next table of tests will be available from a contract laboratory
through the NWQL. For information on how to submit samples to the contractor,
along with additional information such as sample batch size limitations,
please contact Bob Brock (RDBROCK) (303) 467-8097. These tests are U.S.
Environmental Protection Agency (USEPA) methods that have been available
from the NWQL. However, they have been requested infrequently, and it
is not economical to maintain them at NWQL.
NAME LAB CODE* PARAMETER REPLACE WITH
CODE
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Cyanide, Bottom Material 1235 00721 B Contract
Antimony, Bottom Material 534 01098 A Contract
Barium, Bottom Material 521 01008 A Contract
Beryllium, Bottom Material 522 01013 A Contract
Molybdenum, Bottom Material 523 01063 A Contract
Strontium, Bottom Material 530 01083 A Contract
Calcium, Whole Water (USEPA) 324 00916 A Contract
Magnesium, Whole Water (USEPA) 325 00927 A Contract
Sodium, Whole Water (USEPA) 326 00929 A Contract
Potassium, Whole Water (USEPA) 327 00937 A Contract
Digestion, USEPA, 124 (preparation Contract
for Ca, Mg, K, Na procedure only)
*The lab codes for these tests will become invalid.
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The NWQL is now offering USEPA drinking-water methods for 47 organic and 14
inorganic constituents regulated by the State of Colorado. These methods
comply with all USEPA drinking-water certification requirements and
constitute the NWQL USEPA-approved drinking-water determinations.
Certification is performed by the State of Colorado and sanctioned by the
USEPA, Region VIII. An NWQL Technical Memorandum on this subject will be
published. If there is interest in using these drinking-water methods prior
to the release of this memo, please contact Al Driscoll (DRISCOLL),
(303) 467-8042.
The NWQL has substantial technical reservations about the tests for Sulfide
and for Hexavalent Chromium in water samples. Both constituents are known to
be unstable, and USEPA-approved field-test kits are available from Hach
Chemical. The NWQL recommends that these constituents be determined onsite
using the Hach field test. NWQL will discontinue the following two tests as
laboratory determinations:
NAME LAB CODE* PARAMETER REPLACE WITH
CODE
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Sulfide, Whole Water 89 00745 A Field test: Hach #8131
Chromium, Hexavalent, 16 01032 A Field Test: Hach #8023
Filtered Water
*The lab codes for these discontinued tests will become invalid.
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The Organic Chemistry Program at the NWQL also examined all analytical
tests to determine which could be eliminated, replaced, or sent to contract
laboratories. These four tests have been requested fewer than 50 times in
1993 and in 1994. The detection limit for the existing USGS Oil and Grease
in Bottom Material method is known to be too high for most purposes, and
there is insufficient need to justify a more sensitive (and expensive) test.
The two Inorganic Carbon methods involve substantial set-up costs when they
are requested. Because of the expense and the small number of requests,
NWQL is discontinuing these tests and offering them only by contract. The
method for Tannin and Lignin had not been requested for several years but
recently has been requested by one District hydrologist; this need is also
being met by contract.
NAME LAB CODE* PARAMETER REPLACE WITH
CODE
------------------------------------------------------------------------------
Oil & Grease, Bottom Material 531 00557 A Contract
Carbon, Inorganic, Whole Water 19 00685 A Contract
Carbon, Inorganic, 306 00691 A Contract
Filtered Water
Tannin and Lignin 138 32240 A Contract
*The lab codes for these discontinued tests will become invalid.
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The NWQL offers many schedules of pesticides in water that are typically
divided into classes of pesticides [organochlorine (OCs), organophosphate
(OPs), Atrazine-types, and carbamates] and combinations of classes.
Schedules are also offered for either whole-water or filtered water (total
or dissolved). For some classes, such as carbamates, the pesticides reside
exclusively in the dissolved fraction because they have high solubilities,
but for two classes, OCs and OPs, the solubilities in water are low enough
that they will partition into the suspended particulate matter to a large
(and variable) extent. The NWQL currently offers four filtered water
schedules of OC and OP pesticides and related compounds. These four
schedules can recover different concentrations of analytes depending on the
amount of particulate matter present, the percent organic carbon on the
particles, and the partition coefficients of each analyte. The NWQL offers
corresponding schedules for whole-water extractions that have better
recoveries of analytes. The whole-water test is less expensive in all
cases because the whole-water schedules do not require filtration.
Current reporting limits are identical. The NWQL proposes to eliminate the
four filtered-water schedules and suggests that its customers use the
corresponding whole-water schedule.
The following table lists the four filtered-water schedules to be eliminated
and the corresponding whole-water schedules that can be used in replacement.
For complete information about these schedules, please see the NWQL 1995
Services Catalog (OFR 95-352, p. 50-52).
Eliminate: Replace with:
Filtered water Schedule No.* Whole water Schedule No.
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Schedule 1316 (OPs) Schedule 1319 (OPs)
Schedule 1321 (OCs) Schedule 1324 (OCs)
Schedule 1331 (OCs + OPs) Schedule 1334 (OCs + OPs)
Schedule 1361 (PCBs) Schedule 1364 (PCBs)
*These filtered-water schedules will become invalid.
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Finally, NWQL proposes to eliminate Schedule 1359 which measures eight
carbamate pesticides in whole-water samples. These pesticides have high
water solubilities, so their concentrations are not expected to change
because of filtration. Schedule 2050/2051 measures 41 similar pesticides
and metabolites in filtered water at much lower detection limits than measured
by Schedule 1359. Therefore, now that Schedule 2050/2051 has become a fully
approved USGS analytical method, Schedule 1359 will be discontinued.
Schedule 2050/2051 costs less than Schedule 1359, includes far more compounds,
and has much lower detection limits.
Eliminate: Replace with:
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Schedule 1359* (carbamates) Schedule 2050/2051
*This schedule will become invalid.
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The Radiochemistry Unit has two analytical determinations to be eliminated
that have not been requested in several years and which have alternative
determinations.
NAME LAB CODE* PARAMETER REPLACE WITH LAB CODE
CODE (PARAM. CODE)
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Radium-228 Filtered 850 81366 A Radium-228 Filtered 1364 (81366 C)
Radon-222 490 82305 A Radon-222 1369 (82330 B)
*The lab codes for these determinations will become invalid.
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The replacement Radium-228 determination uses only 2 liters instead of
7 liters of sample, has the same method detection limit (MDL) (1.0 pCi/L),
and is approved by USEPA. The replacement Radon-222 determination is less
expensive, is expected to be approved by USEPA, and provides results that
are available more quickly. The Radon-222 test to be eliminated uses a
fragile, expensive bubbler system and provides lower detection limits than
most customers require.
Effect on Data Base: There is no effect on existing data.
Supersedes: None
Key Words: Eliminate Procedures, Trace Metals, Solids, Nitrogen
Antek, Sulfide, Hexavalent Chromium, Oil and Grease,
Carbon, Filtered, Pesticides, Carbamates, Radium-228,
Radon-222
Distribution: Water Resources Division Distribution "E" plus the Netnews
usgs.labnews & .water.quality; and
http://wwwnwql.cr.usgs.gov/