[Federal Register Volume 84, Number 204 (Tuesday, October 22, 2019)]
[Proposed Rules]
[Pages 56590-56624]
[FR Doc No: 2019-22437]

Vol. 84

Tuesday,

No. 204

October 22, 2019

Part III

Environmental Protection Agency

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40 CFR Part 136

Clean Water Act Methods Update Rule for the Analysis of Effluent;
Proposed Rule

Federal Register / Vol. 84 , No. 204 / Tuesday, October 22, 2019 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 136

[EPA-HQ-OW-2018-0826; FRL-9995-22-OW]
RIN 2040-AF84

Clean Water Act Methods Update Rule for the Analysis of Effluent

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing changes
to its test procedures required to be used by industries and
municipalities when analyzing the chemical, physical, and biological
properties of wastewater and other environmental samples for reporting
under the EPA's National Pollutant Discharge Elimination System (NPDES)
permit program. The Clean Water Act requires the EPA to promulgate
these test procedures (analytical methods) for analysis of pollutants.
The EPA anticipates that these proposed changes will provide increased
flexibility for the regulated community in meeting monitoring
requirements while improving data quality. In addition, this proposed
update to the CWA methods would incorporate technological advances in
analytical technology. As such, the EPA expects that there will be no
negative economic impacts resulting from these proposed changes.

DATES: Comments on this proposed rule must be received on or before
December 23, 2019.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OW-2018-0826, by any of the following means:
     Federal eRulemaking Portal: https://www.regulations.gov/_
(preferred way of receiving comments): Follow the online instructions
for submitting comments.
     Email<EMAIL_ADDRESS>Include Docket ID No. EPA-HQ-OW-
2018-0826 in the subject line of the message.
     Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Office of Water Docket, Mail Code 28221T, 1200 Pennsylvania
Avenue NW, Washington, DC 20460.
     Hand Delivery/Courier: EPA Docket Center, WJC West
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004.
The Docket Center's hours of operations are 8:30 a.m.-4:30 p.m.,
Monday-Friday (except Federal Holidays).
    Instructions: All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to https://www.regulations.gov/, including any personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see Section I.B ``What Should I
Consider as I Prepare My Comments for the EPA'' heading of the
SUPPLEMENTARY INFORMATION section of this document.
    Docket: All documents in the docket are listed in the
www.regulations.gov index. Although listed in the index, some
information in the docket is not publicly available, e.g., Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Certain other material, such as copyrighted
material, will be publicly available only in hard copy. Publicly
available docket materials are available either electronically in
www.regulations.gov or in hard copy at the Water Docket in EPA Docket
Center, EPA/DC, EPA West William J. Clinton Building, Room 3334, 1301
Constitution Avenue NW, Washington, DC. The Public Reading Room is open
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal
holidays. The telephone number for the Public Reading Room is 202-566-
1744, and the telephone number for the Water Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Meghan Hessenauer, Engineering and
Analysis Division (4303T), Office of Water, Environmental Protection
Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460-0001;
telephone:<PHONE_NUMBER>; email<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information
II. Overview
III. Statutory Authority
IV. Purpose and Summary of Proposed Rule
V. Statutory and Executive Order Reviews

I. General Information

A. Does this action apply to me?

    Entities potentially affected by the requirements of this proposed
action include:

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           Category            Examples of potentially affected entities
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State, Territorial, and        States, territories, and tribes
 Indian Tribal Governments.     authorized to administer the National
                                Pollutant Discharge Elimination System
                                (NPDES) permitting program; states,
                                territories, and tribes providing
                                certification under CWA section 401;
                                state, territorial, and tribal-owned
                                facilities that must conduct monitoring
                                to comply with NPDES permits.
Industry.....................  Facilities that must conduct monitoring
                                to comply with NPDES permits.
Municipalities...............  Publicly Owned Treatment Works (POTWs) or
                                other municipality-owned facilities that
                                must conduct monitoring to comply with
                                NPDES permits.
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    This table is not exhaustive, but rather provides a guide for
readers regarding entities likely to be affected by this action. This
table lists types of entities that the EPA is now aware of that could
potentially be affected by this action. Other types of entities not
listed in the table could also be affected. To determine whether your
facility is affected by this action, you should carefully examine the
applicability language at 40 CFR 122.1 (NPDES purpose and scope), 40
CFR 136.1 (NPDES permits and CWA) and 40 CFR 403.1 (pretreatment
standards purpose and applicability). If you have questions regarding
the applicability of this action to a particular entity, consult the
appropriate person listed in the preceding FOR FURTHER INFORMATION
CONTACT section.

B. What should I consider as I prepare my comments for the EPA?

    Submit your comments, identified by Docket ID No. EPA-HQ-OW-2018-
0826, at https://www.regulations.gov (preferred way of receiving
comments), or the other means identified in the ADDRESSES section. Once
submitted, comments cannot be edited or removed from the docket. The
EPA may publish any comment received to its public docket. Do not
submit electronically any information you consider to be CBI or other
information whose disclosure is restricted by statute. Do not submit
CBI to the EPA through www.regulations.gov or email. Clearly mark the
part or all of the information that you claim to be CBI. For CBI
information in a disk that you mail to the EPA, mark the outside

of the disk as CBI and then identify electronically within the disk the
specific information that is claimed as CBI. In addition to one
complete version of the comment that includes information claimed as
CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures for handling and protection of CBI set forth in 40 CFR part
2.
    Multimedia submissions (audio, video, etc.) must be accompanied by
a written comment. The written comment is considered the official
comment and should include discussion of all points you wish to make.
The EPA will generally not consider comments or comment contents
located outside of the primary submission (i.e., on the web, cloud, or
other file sharing system). For additional submission means or methods,
the full EPA public comment policy, information about CBI or multimedia
submissions, and general guidance on making effective comments, please
visit https://www.epa.gov/dockets/commenting-epa-dockets.

II. Overview

    This preamble describes the reasons for the proposed rule; the
legal authority for the proposed rule; a summary of the proposed
changes and clarifications; and explanation of the abbreviations and
acronyms used in this document. In addition, this preamble solicits
comment and data from the public.

Abbreviations and Acronyms Used in the Preamble and Proposed Rule Text

2-CEVE: 2-Chloroethylvinyl ether
AA: Atomic Absorption
ADMI: American Dye Manufacturers Institute
ASTM: ASTM International \1\
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    \1\ Formerly known as the American Society for Testing and
Materials (ASTM).
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ATP: Alternate Test Procedure
BHI: Brain heart infusion
BOD5: 5-day Biochemical Oxygen Demand
CAS: Chemical Abstract Services
CATC: Cyanide Amenable to Chlorination
CCB: Continuing calibration blank
CCV: Continuing calibration verification
CFR: Code of Federal Regulations
COD: Chemical Oxygen Demand
CWA: Clean Water Act
EC-MUG: EC broth with 4-methylumbelliferyl-[beta]-D-glucuronide
EDTA: Ethylenediaminetetraacetic acid
ELAB: Environmental Laboratory Advisory Board
EPA: Environmental Protection Agency
FLAA: Flame Atomic Absorption Spectroscopy
GC: Gas Chromatography
GFAA: Graphite Furnace Atomic Absorption Spectroscopy
ICP/AES: Inductively Coupled Plasma-Atomic Emission Spectroscopy
ICP/MS: Inductively Coupled Plasma-Mass Spectrometry
ILI: Independent Laboratories Institute
IPR: Initial Precision and Recovery
LCS: Laboratory Control Sample
MDL: Method Detection Limit
MF: Membrane Filtration
MgCl2: Magnesium Chloride
MPN: Most Probable Number
MS/MSD: Matrix Spike/Matrix Spike Duplicate
MS: Mass Spectrometry
NA-MUG: Nutrient Agar with 4-methylumbelliferyl-[beta]-D-glucuronide
NECi: A shortened name used by the Nitrate Elimination Company, Inc.
NPDES: National Pollutant Discharge Elimination System
NTTAA: National Technology Transfer and Advancement Act
OPR: Ongoing Precision and Recovery
QC: Quality Control
STGFAA: Stabilized Temperature Graphite Furnace Atomic Absorption
Spectroscopy
TKN: Total Kjeldahl Nitrogen
TOC: Total Organic Carbon
USGS: United States Geological Survey
VCSB: Voluntary Consensus Standards Body

III. Statutory Authority

    The EPA is proposing this regulation under the authorities of
sections 301(a), 304(h), and 501(a) of the CWA; 33 U.S.C. 1311(a),
1314(h), and 1361(a). Section 301(a) of the CWA prohibits the discharge
of any pollutant into navigable waters unless the discharge complies
with, among other provisions, an NPDES permit issued under section 402
of the CWA. Section 304(h) of the CWA requires the Administrator of the
EPA to ``. . . promulgate guidelines establishing test procedures for
the analysis of pollutants that shall include the factors which must be
provided in any certification pursuant to [section 401 of the CWA] or
permit application pursuant to [section 402 of the CWA].'' Section
501(a) of the CWA authorizes the Administrator to ``. . . prescribe
such regulations as are necessary to carry out this function under [the
CWA].'' The EPA generally has codified its test procedure regulations
(including analysis and sampling requirements) for CWA programs at 40
CFR part 136, though some requirements are codified in other parts
(e.g., 40 CFR Chapter I, Subchapters N and O).

IV. Purpose and Summary of Proposed Rule

    NPDES permits must include conditions designed to ensure compliance
with the technology-based and water quality-based requirements of the
CWA, including in many cases, restrictions on the quantity of specific
pollutants that can be discharged as well as pollutant measurement and
reporting requirements. Often, entities have a choice in deciding which
approved test procedure they will use for a specific pollutant because
the EPA has approved the use of more than one method.\2\
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    \2\ NPDES permit regulations also specify that the approved
method needs to be sufficiently sensitive. See 40 CFR 122.21.e.3.
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    The procedures for the analysis of pollutants required by CWA
section 304(h) are a central element of the NPDES permit program.
Examples of where these EPA-approved analytical methods must be used
include the following: (1) Applications for NPDES permits, (2) sampling
or other reports required under NPDES permits, (3) other requests for
quantitative or qualitative effluent data under the NPDES regulations,
(4) State CWA 401 certifications and (5) sampling and analysis required
under the EPA's General Pretreatment Regulations for Existing and New
Sources of Pollution, 40 CFR 136.1 and 40 CFR 403.12(b)(5)(v).
    Periodically, the EPA proposes to update the approved methods in 40
CFR part 136. In general, the changes proposed in this action fall into
the following categories. The first is new or revised methods published
by the VCSBs or the USGS that are similar to methods previously adopted
as EPA-approved methods in 40 CFR part 136. The second category is
methods the EPA has reviewed under the Agency's national ATP program
and preliminarily concluded are appropriate for nationwide use.
Finally, the EPA is proposing certain corrections or amendments to the
text and tables of 40 CFR part 136. The EPA is proposing adoption of
these revisions to improve data quality, update methods to keep current
with technology advances, and provide the regulated community with
greater flexibility. The following paragraphs provide details on the
proposed revisions.

A. Changes to 40 CFR 136.3 To Include New Versions of Previously
Approved EPA Methods

    The EPA proposes to add the latest version of EPA Method 1623 to
Table IH. The latest version of Method 1623 (labeled 1623.1) includes
updated acceptance criteria for IPR, OPR, and MS/MSD, and
clarifications and revisions based on user questions and feedback about
Method 1623 over the past 19 years.

B. Methods Incorporated by Reference

    Currently, hundreds of methods and ATPs are incorporated by
reference within 40 CFR part 136. In most cases, 40 CFR part 136
contains multiple approved methods for a single pollutant, and
regulated entities often have a choice in selecting a method. The
proposed rule contains revisions to VCSB methods that are currently
incorporated by reference. Two VCSBs have made such revisions, Standard
Methods and ASTM. The proposed VCSB methods are consistent with the
requirements of the National Technology Transfer and Advancement Act
(NTTAA), under which federal agencies use technical standards developed
or adopted by the VCSBs if compliance would not be inconsistent with
applicable law or otherwise impracticable (see Section V.I below). The
proposed VCSB methods are available on their respective websites
(www.standardmethods.org/ and www.astm.org) to everyone at a cost
determined by the VCSB, generally from $40 to $80. Both organizations
also offer memberships or subscriptions that allow unlimited access to
their methods. The cost of obtaining these methods is not a significant
financial burden for a discharger or environmental laboratory, making
the methods reasonably available. Finally, this proposal also includes
USGS methods and vendor ATPs, all of which the EPA proposes to
incorporate by reference. The ATPs and USGS methods are available free
of charge on their respective websites (flowinjection.com, mn-net.com,
micrologylabs.com, and USGS.gov), enabling the EPA to conclude that the
USGS methods and ATPs incorporated by reference are reasonably
available.

C. Changes to 40 CFR 136.3 To Include New Versions of Approved Standard
Methods

    The EPA is proposing to approve new versions of Standard Methods
methods previously approved in 40 CFR part 136. The newer versions
provide clarifications or make editorial corrections. As was the case
with the previous methods update rule (82 FR 40836-40941, August 28,
2017), the EPA generally proposes to approve and include in 40 CFR part
136 only the most recent version of a method published by the Standard
Methods Committee. The EPA is proposing to list only one version of the
method with the year of publication designated by the last four digits
in the method number (e.g., Standard Methods Method 3111 B-2011). The
date indicates the date of the specific revision to the method. This
allows use of a specific method in any edition of the hard copy
publication of Standard Methods for the Examination of Water &
Wastewater (Standard Methods) that includes a method with the same
method number and year of publication.
    The proposed revisions to Standard Methods methods previously
approved in 40 CFR part 136 will not affect the performance of the
method. Below is a list of the Standard Methods methods the EPA is
proposing to include in 40 CFR part 136. Each entry contains the
proposed Standard Methods number and date, the parameter, and a brief
description of the analytical method. The methods listed below are
organized according to the table at 40 CFR part 136 in which they
appear.
    The EPA proposes to make the following changes to Tables IA and IH
at 40 CFR part 136:
    1. Standard Methods Method 9221 (B, E, F)-2014: Method 9221B-2014
Coliform (total); analyzes for total coliforms in non-potable waters
using lauryl tryptose broth (LTB), all presumptive growth LTB tubes are
confirmed in brilliant green lactose bile broth (BGLB). Method 9221E-
2014 Coliform (fecal); analyzes all presumptive growth LTB tubes for
fecal coliform using EC broth. Method 9221F-2014 E. coli; analyzes all
presumptive growth LTB tubes for E. coli using EC-MUG. The number of
positive tubes (BGLB, EC broth or EC-MUG) is used to determine the most
probable number (MPN).
    2. Standard Methods Method 9222 (B, D, I)-2015: Method 9222B-2015
Coliform (total); analyzes for total coliforms in non-potable waters by
filtration through a 0.45-[micro]m membrane filter and plated on mEndo
or LES Endo agar. Method 9222D-2015 Coliform (fecal); analyzes for
fecal coliforms in non-potable waters by filtration through a 0.45-
[micro]m membrane filter plated on mFC medium. Method 9222 I-2015 E.
coli; membrane filtration (MF), analyzes presumptive positive filters
from Method 9222B and 9222D using nutrient agar plates with MUG (NA-
MUG) which are examined under a longwave UV lamp.
    3. Standard Methods Method 9223B-2016, E. coli, multiple tube/
multiple well. This method analyzes non-potable waters for E. coli
using commercially available enzyme substrate media that is mixed with
the sample and placed in multiple tubes or multiple well trays,
incubated and examined under ambient light for Coliform (total) and
under a longwave UV lamp for E. coli.
    4. Standard Methods Method 9230 (B, C)-2013: Method 9230B-2013
Fecal Streptococci; analyzes non-potable waters for streptococci using
azide dextrose broth (ADB), Presumptive positive ADB tubes are
confirmed by streaking onto bile esculin azide agar (BEA). Method
9230C-2013 Enterococci; analyzes non-potable waters by filtration
through a 0.45-[micro]m membrane filter and plated on mE agar.
    The EPA proposes to make the following changes to Table IB at 40
CFR part 136:
    1. Standard Methods Methods: Method 2540B-2015, total solids; a
sample aliquot is evaporated in a pre-weighed evaporating dish at 103-
105 [deg]C. Method 2540C-2015 filterable residue (total dissolved
solids); a sample aliquot is filtered through a glass fiber filter and
the filtrate is evaporated on a pre-weighed dish to constant weight at
180 [deg]C. Method 2540D-2015 non-filterable residue (total suspended
solids); a sample aliquot is filtered through a pre-weighed glass fiber
filter which is then dried to constant weight at 103-105 [deg]C. Method
2540E-2015 volatile residue (fixed and volatile solids); the residue
obtained from the determination of total (Method 2540B), filterable
(Method 2540C) or non-filterable residue (Method 2540D) is ignited at
550 [deg]C in a muffle furnace. Method 2540E-2015 settleable residue
(settleable solids); settleable matter is measured with an Imhoff cone
either volumetrically or gravimetrically.
    2. Standard Methods Method 4500-CN- (B-G)-2016, cyanide:
Cyanides are measured after preliminary treatment of samples to remove
interferences (4500-CN- B) and manual distillation with
magnesium chloride (MgCl2) (4500-CN- C) followed
by: Titration with silver nitrate (4500-CN- D),
spectrophotometric measurement after cyanide in the alkaline distillate
is converted to CNCl (4500-CN- E), potentiometric
measurement using an ion selective electrode (4500-CN- F),
and cyanide amenable to chlorination (CATC) in which a portion of the
sample is chlorinated at high pH and cyanide levels in the chlorinated
sample are determined after manual distillation followed by titrimetric
or spectrophotometric measurement. Amenable cyanide is calculated by
the difference between the results for cyanide in the unchlorinated
sample and the results for the chlorinated sample (4500-CN-
G).
    3. Standard Methods Method 4500-NO3- D-2016,
nitrate (as nitrogen), measured using an ion-selective electrode (ISE)
that develops a potential across a thin, inert membrane holding in
place a water-immiscible liquid ion exchanger.

    4. Standard Methods Method 4500-NO3- (E, F,
and H)-2016, nitrate-nitrite (as nitrogen): Nitrate is reduced to
nitrite using a cadmium-copper column, followed by diazotization to
form a colored azo dye, which is measured by colorimetry either
manually (4500 NO3- E) or automated (4500
NO3- F); or by reduction of nitrate to nitrite
using hydrazine followed by automated colorimetric measurement of
nitrite after diazotization (4500 NO3- H).
    5. Standard Methods Method 4500-NO3- (E and
F)-2016, nitrite (as nitrogen), colorimetric: Bypasses the cadmium
reduction step and measures nitrite after diazotization either by
manual or automated colorimetric analysis.
    6. Standard Methods Method 4500-O (B-F, and G)-2016, measurement of
oxygen (dissolved), using the Winkler iodometric titration procedure
with modifications to eliminate or minimize certain interferences if
necessary based on sample type (4500-O B through F), or by use of
polarographic or galvanic membrane electrodes (4500-O G).
    7. Standard Methods Method 5210 B-2016, biochemical oxygen demand
(BOD5), dissolved oxygen depletion. The BOD5 test
is an indirect measurement of organic matter; it measures the change in
DO concentration caused by microorganisms as they degrade organic
matter in a sample held in a stoppered bottle incubated for 5 days in
the dark at 20 [deg]C.
    8. Standard Methods Method 5310 (B, C)-2014, total organic carbon
(TOC), combustion, heated persulfate or UV persulfate oxidation: Method
5310B-2014, high-temperature combustion; a sample aliquot is combusted,
transported in a carrier gas stream and measured via a nondispersive
infrared analyzer, or titrated coulometrically Method 5310C-2014,
persulfate-ultraviolet or heated-persulfate oxidation method;
persulfate oxidizes organic carbon, the produced CO2 is then
purged and measured by either nondispersive infrared (NDIR) analyzer,
be coulometrically titrated, or separated from the liquid stream by a
membrane that specifically allows CO2 to pass into high-
purity water where the change in the high-purity water's conductivity
corresponds to the amount of CO2 passing the membrane.
    The EPA is also proposing one revision to a previously approved
Standard Methods method for which the Standard Methods Committee has
adopted updates. This modification includes minor procedural changes
that do not affect the performance of the method.
    The EPA proposes to make the following change to Table IA and Table
IH at 40 CFR part 136:
    1. The EPA proposes that the MPN method Standard Methods Method
9221 F.2-2014 be approved as an acceptable method for detecting
thermotolerant coliforms and E. coli simultaneously. This method
analyzes Coliform (fecal) and E. coli using EC broth with 4-
methylumbelliferyl-[beta]-D-glucuronide (EC-MUG) with inverted vials.

D. Changes to 40 CFR 136.3 To Include New Standard Methods Methods
Based on Previously Approved Technologies

    The EPA is proposing these changes based on the National Technology
Transfer and Advancement Act of 1995 (NTTAA), Public Law 104-113, which
states that federal agencies and departments shall use technical
standards developed or adopted by the VCSBs if compliance would not be
inconsistent with applicable law or otherwise impracticable. These
methods submitted by the Standard Methods Committee are consistent with
other methods already approved at 40 CFR part 136.
    1. The EPA proposes to add Standard Methods Method 4500-
CN- N-2016 to Table IB for Cyanide, total. Cyanide is
measured after preliminary treatment of samples and manual distillation
with magnesium chloride (MgCl2) followed by automated
spectrophotometric measurement after conversion to CNCl. This method is
similar to the currently approved EPA Method 335.4, USGS Method I-4302-
85, and Lachat Method 10-204-00-1-X, and uses semi-automated
spectrophotometric measurement of cyanide.
    2. The EPA proposes to add Standard Methods Method 4500-
NO3- I-2016 to Table IB for combined nitrate-
nitrite, nitrite (bypass the reduction column) and nitrate by
subtraction. Nitrate is reduced to nitrite using a cadmium-copper
column followed by diazotization to form an azo dye which is measured
by colorimetry. The cadmium reduction column may be by-passed for
measurement of nitrite only. The value obtained for nitrite may be
subtracted from the value obtained for combined nitrate-nitrite to
calculate the concentration of nitrate. This method is similar to the
currently approved EPA Method 353.2, Standard Methods Method 4500-
NO3- F-2011, ASTM Method D3867-04 (A), and USGS
Method I-2545-90, and uses automated cadmium reduction and
spectrophotometric measurement of nitrite.
    3. The EPA proposes to add Standard Methods Method 4500-
NO3- J-2018 to Table IB for measurement of
combined nitrate-nitrite, for measurement of nitrite when bypassing the
enzymatic reduction step, and for measurement of nitrate by
subtraction. Nitrate is reduced to nitrite by an enzymatic reaction.
The nitrite is diazotized to yield an azo dye which is measured
colorimetrically. The enzyme reduction step may be by-passed for
measurement of nitrite singly. The value obtained for nitrite may be
subtracted from the value obtained for combined nitrate-nitrite to
calculate the concentration of nitrate. This method is similar to the
currently approved NECi Method N07-0003, USGS Method I-2547-11, and
USGS Method I-2548-11.
    4. The EPA proposes to add Standard Methods Method 4500-O H-2016 to
Table IB for dissolved oxygen. This method uses a luminescent-based
sensor for measurement of dissolved oxygen. The method is similar to
the currently approved Hach Method 10360, In-Situ Method 1002-8-2009,
and ASTM Method D888-09 (C).

E. Changes to 40 CFR 136.3 To Include New Versions of Approved ASTM
Methods

    The EPA is proposing to approve new versions of ASTM methods
previously approved in 40 CFR part 136 for the same reasons outlined in
the first paragraph of Section IV.C above. These changes to currently
approved ASTM methods in 40 CFR part 136 include minor clarifications
and editorial changes, and in some instances, minor procedural changes.
None of these proposed changes will affect the performance of the
method. The following describes the changes to current ASTM methods
that the EPA proposes to include in 40 CFR part 136. Each entry
contains (in the following order): Proposed ASTM method number (the
last two digits in the method number represent the year ASTM
published), the parameter, a brief description of the analytical
technique, and a brief description of any procedural changes in this
revision from the last approved version of the method. The methods
listed below are organized according to the table at 40 CFR part 136 in
which they appear.
    The EPA proposes the following changes to Table IB at 40 CFR part
136:
    1. ASTM Method D511-14 (A, B), calcium and magnesium, titrimetric,
(EDTA), AA direct aspiration: Method D511-14 A, titrimetric; the pH of
the sample is adjusted to 10 (for calcium), then to 12-13 (for
magnesium) and titrated with ethylenediamine tetraacetic acid (EDTA) to
form complexes with calcium and

magnesium ions which react with an indicator to form a colored product.
The volume of titrant used to affect the color change is proportional
to the concentrations of calcium and magnesium in the sample. Method
D511-14 B, AA direct aspiration; the sample is acidified and analyzed
by atomic absorption. The concentrations of calcium and magnesium in
the samples are proportional to the amount of light absorbed during the
analysis, and are determined in comparison to a standard curve.
    This version adds specifications for filter paper.
    2. ASTM Method D512-12 chloride ion (A, B), titrimetric (mercuric
nitrate), titration (silver nitrate): Method D512-12A, titrimetric
mercuric nitrate; the sample is acidified and titrated with mercuric
nitrate in the presence of a diphenylcarbazonebromophenol blue
indicator. Method D512-12B, titrimetric silver nitrate; sample pH is
adjusted to phenolphthalein endpoint and titrated with silver nitrate
in the presence of potassium chromate. The volume of titrant used to
affect the color change in either method is proportional to the
concentration of chloride in the sample. This version corrects one term
in the calculation of the chloride calculation.
    3. ASTM Method D516-16, sulfate ion, turbidimetric. In this method,
sulfate ions are converted to barium sulfate to form a suspension. The
turbidity of the suspension is measured with a nephelometer,
spectrophotometer, or photoelectric colorimeter, and compared to a
standard curve to determine the sulfate concentration in the sample.
This version adds specifications for filter paper.
    4. ASTM Method D858-17 (A-C), manganese, atomic absorption (AA)
direct aspiration, AA furnace. The sample is acid digested and analyzed
by direct aspiration atomic absorption or graphite furnace atomic
absorption. The concentration of manganese in the sample is
proportional to the amount of light absorbed and is determined in
comparison to a standard curve. There are no procedural changes.
    5. ASTM Method D859-16, silica, colorimetric, manual. In this
method, soluble silica in the sample is reacted with molybdate then
reduced to form a blue complex in solution. The intensity of the blue
complex is determined with a spectrophotometer or filter photometer and
the concentration of silica is determined by comparison with a standard
curve. There are no procedural changes.
    6. ASTM Method D888-12 (A-C) dissolved oxygen, Winkler, electrode,
luminescent-based sensor: Method D888-12A measures dissolved oxygen
using the Winkler iodometric titration procedure. The volume of titrant
used is proportional to the concentration of dissolved oxygen in the
sample. Method D888-12B measures dissolved oxygen in the sample with an
electrochemical probe that produces an electrical potential which is
logarithmically proportional to the concentration of dissolved oxygen
in the sample. Method D888-12C measures dissolved oxygen with a
luminescence-based sensor probe that employs frequency domain lifetime-
based luminescence quenching and signal processing. This version adds
information on a two-point calibration and updated performance
information from an interlaboratory study to D888-12C.
    7. ASTM Method D1067-16, acidity or alkalinity, electrometric
endpoint or phenolphthalein endpoint; electrometric or colorimetric
titration to pH 4.5, manual. The acidity or alkalinity of the sample is
determined by titration to a specific pH endpoint which is determined
by colorimetry or with a pH electrode. The acidity or alkalinity is
proportional to the volume of titrant required to affect the pH change.
There are no procedural changes.
    8. ASTM Method D1068-15 (A-C), iron, AA direct aspiration; AA
furnace; colorimetric (Phenanthroline): The sample is acid digested and
analyzed by either direct aspiration atomic absorption, graphite
furnace atomic absorption, or colorimetry. The concentration of iron in
the sample is proportional to the amount of light absorbed and is
determined in comparison to a standard curve. This version adds
specifications for filter paper.
    9. ASTM Method D1126-17, hardness, titrimetric (EDTA). The pH of
the sample is adjusted and an indicator is added forming a red color.
The mixture is titrated until the color changes from red to blue. The
volume of titrant used to affect the color change is proportional to
the hardness in the sample. There are no procedural changes.
    10. ASTM Method D1179-16 (A, B); fluoride ion, manual distillation,
electrode, manual: Method D1179A, manual distillation; the sample is
distilled as hydrofluorosilic acid and determined by ion-selective
electrode. Method D1179B, electrode; the fluoride ion is determined
potentiometrically with an ion-selective electrode in conjunction
without sample distillation. There are no procedural changes.
    11. ASTM Method D1246-16, bromide ion, electrode. The bromide in
the sample is determined potentiometrically with an ion-selective
electrode, either through comparison to a standard curve or through a
direct readout on the instrument. There are no procedural changes.
    12. ASTM Method D1252-06 (A, B) (Reapproved 2012), chemical oxygen
demand, titrimetric, spectrophotometric. This is the 2012 reapproval of
the 2006 ASTM method: Method D1252-06A, titrimetric; measures the loss
of the hexavalent dichromate ion by reflux digestion followed by
titration. The chemical oxygen demand in the sample is determined by
comparison to a standard curve. Method D1252-06B, spectrophotometric;
uses a spectrophotometer to measure the loss of the hexavalent
dichromate ion at 420 nm or the increase in the trivalent chromium ion
at 600 nm, after closed digestion and determines the chemical oxygen
demand by comparison to a standard curve. There are no procedural
changes.
    13. ASTM Method D1253-14, residual chlorine, amperometric direct.
The concentration of chlorine in the sample is determined by titration
with phenylarsine oxide, using an amperometric probe that responds to
chlorine to determine when the titration is complete. The chlorine
concentration in the sample is proportional to the volume of titrant
used. There are no procedural changes.
    14. ASTM Method D1426-15 (A, B), ammonia nitrogen, Nesslerization,
electrode: Method D1426A, Nesslerization; an aliquot is Nesslerized and
the ammonia content determined colormetrically. Method D1426B,
electrode; ammonia is potentiometric determined using a gas-permeable
ion-selective electrode, either through comparison to a standard curve
or through a direct readout on the instrument using. A lengthy section
of QC requirements was added to the Nesslerization procedure (D1426A)
that parallels the QC discussion that was already in the B procedure.
Both procedures added information on use of commercially prepared
standards and filter paper.
    15. ASTM Method D1687-17 (A-C), chromium (total) and dissolved
hexavalent chromium, colorimetric (diphenyl-carbazide); AA direct
aspiration; AA furnace: Method D1687-17A, chromium (dissolved);
measures dissolved hexavalent chromium by reacting it with diphenyl-
carbohydrazide to produce a reddish-purple color that is measured with
a

spectrophotometer or filter photometer. The concentration in the sample
is proportional to the intensity of the color. Method D1687-17B,
chromium (total); the sample is acid digested and analyzed by direct
aspiration atomic absorption. Method D1687-17C, chromium (total); the
sample is acid digested and analyzed by graphite furnace atomic
absorption. The concentration of total chromium in the sample is
proportional to the amount of light absorbed during the analysis and is
determined in comparison to a standard curve. The changes mirror those
for the other metals methods. The QC frequencies for method blank,
continuing calibration verification (CCV), continuing calibration blank
(CCB), matrix spike, and duplicate analyses are now based on a
laboratory-defined batch of up to 20 samples.
    16. ASTM Method D1688-17 (A-C), copper, AA direct aspiration, AA
furnace. The sample is acid digested and analyzed by direct aspiration
atomic absorption (D1688-17A and B) or graphite furnace atomic
absorption (D1688-17B). The concentration of copper in the sample is
proportional to the amount of light absorbed and is determined in
comparison to a standard curve. The changes mirror those for the other
metals methods. The proposed changes also clarify the requirements for
a multi-point calibration by discussing it in the calibration section
as well as the QC section of all three procedures. The QC frequencies
for method blank, CCV, CCB, matrix spike, and duplicate analyses are
now based on a laboratory-defined batch of up to 20 samples.
    17. ASTM Method D1691-17 (A, B), zinc, AA direct aspiration. Method
D1691-17A; the sample is acid digested and analyzed by direct
aspiration atomic absorption. Method D1691-17B; the sample is processed
by chelation-extraction and analyzed by atomic absorption. The
concentration of zinc in the sample is proportional to the amount of
light absorbed and is determined in comparison to a standard curve. The
changes mirror those for the other metals methods. The QC frequencies
for method blank, CCV, CCB, matrix spike, and duplicate analyses are
now based on a laboratory-defined batch of up to 20 samples.
    18. ASTM Method D1783-01 (A, B) (Reapproved 2012), phenols, manual
distillation followed by manual colorimetric (4AAP). The sample is
distilled, the distillate pH is adjusted to 10.0, and reacted with 4-
aminoantipyrine to form a colored product. In Method D1783-01A, the
colored product is extracted from the sample with chloroform and
measured with a photometer at 460 nm. In Method D1783-01B, the colored
product is measured without extraction, using a photometer at 510 nm.
The concentration of phenolics is determined in comparison to a
standard curve. There are no procedural changes.
    19. ASTM Method D1886-14 (A-C), nickel AA direct aspiration,
chelation extraction AA and AA furnace. Method D1886-14A, the sample is
acid digested and analyzed by direct aspiration atomic absorption.
Method D1886-14B, the sample is acid digested and the nickel chelated
and extracted. The extract is analyzed by direct aspiration atomic
absorption. Method D1886-14C, the sample is acid digested and analyzed
by graphite furnace atomic absorption. The concentration of nickel in
the sample is proportional to the amount of light absorbed during the
analysis and is determined in comparison to a standard curve. The
changes mirror those for the other metals methods. The QC frequencies
for method blank, CCV, CCB, matrix spike, and duplicate analyses are
now based on a laboratory-defined batch of up to 20 samples.
    20. ASTM Method D2036-09 (A, B) (Reapproved 2015), A, total
cyanide, manual distillation followed by gas diffusion amperometry,
titrimetric, spectrophotometric, ion chromatography, ion selective
electrode, B, available (amenable) cyanide, manual distillation
followed by titrimetric or spectrophotometric. The cyanide in the
sample is distilled and trapped in a sodium hydroxide solution. Method
D2036-09A, the cyanide is treated with strong acid and a catalyst
during distillation and measured by titration, gas diffusion
amperometry, spectrophotometry, ion-selective electrode, ion
chromatography, or flow injection analysis. Method D2036-09B, cyanide
amenable to chlorination is determined by comparing the results for one
sample aliquot analyzed for total cyanide and a second aliquot that is
treated with calcium hypochlorite prior to analysis by Method D2036-
09A. There are no procedural changes.
    21. ASTM Method D2972-15 (A-C), arsenic, colorimetric, AA gaseous
hydride, AA furnace. The sample is digested with nitric and sulfuric
acids. Method D2972-15A, arsenic is trapped in a solution of silver
diethyldithiocarbamate in pyridine which produces a red-colored product
that is analyzed photometrically by comparison to a standard curve.
Method D2972-15B, arsenic in the digested sample is determined by
hydride generation atomic absorption. Method D2972-15C, arsenic in the
digested sample is determined by graphite furnace atomic absorption.
The changes mirror those for the other metals methods. The QC
frequencies for method blank, CCV, CCB, matrix spike, and duplicate
analyses are now based on a laboratory-defined batch of up to 20
samples.
    22. ASTM Method D3223-17, total mercury, cold vapor, manual.
Mercury in the sample is converted to the mercuric ion which is reduced
to elemental mercury, purged from the sample, and analyzed by cold
vapor atomic absorption. The changes mirror those for the other metals
methods, but this version changes the acceptance limit for the CCV from
10% to 15% and adds a requirement for a CCB. Given that the most
comparable EPA procedure, Method 245.1, does not include a CCV
requirement or an acceptance limit, the change of the acceptance limit
from 10% to 15% in the revised ASTM method represents a requirement
that is more stringent than that required in the EPA's procedure and
therefore, the change to the ASTM method is not an impediment to its
approval.
    23. ASTM Method D3373-17, vanadium, AA furnace. The sample is
digested with nitric acid and analyzed by graphite furnace atomic
absorption. The concentration of vanadium in the sample is proportional
to the amount of light absorbed during the graphite furnace atomic
absorption analysis and is determined in comparison to a standard
curve. The changes mirror those for the other metals methods. The
proposed changes clarify the requirements for a multi-point calibration
by discussing it in the calibration section as well as the QC section
of all three procedures. The QC frequencies for method blank, CCV, CCB,
matrix spike, and duplicate analyses are now based on a laboratory-
defined batch of up to 20 samples.
    24. ASTM Method D3557-17 (A-D), cadmium, AA direct aspiration,
voltammetry, AA furnace. Method D3557-17A, the sample is acid digested
and analyzed by direct aspiration atomic absorption. Method D3557-17B,
the sample is acid digested, the digestate is chelated and extracted.
The extract analyzed by direct aspiration atomic absorption. Method
D3557-17C, the sample is acid digested and analyzed by differential
pulse anodic stripping voltametry. Method D3557-17D, the sample is
digested with nitric acid and analyzed by graphite furnace atomic
absorption. The concentration of cadmium in the sample is determined in
comparison to a standard curve. The changes mirror those for the other

metals methods. The proposed changes also clarify requirements for a
multi-point calibration by discussing it in the calibration section as
well as the QC section of all three procedures. The QC frequencies for
method blank, CCV, CCB, matrix spike, and duplicate analyses are now
based on a laboratory-defined batch of up to 20 samples, as opposed to
10 samples previously.
    25. ASTM Method D3558-15 (A-C), cobalt, AA direct aspiration,
chelation extraction AA, and AA furnace. Method D3558-15A, the sample
is acid digested and analyzed by direct aspiration atomic absorption.
Method D3558-15B, the sample is acid digested, chelated and extracted.
The extract is analyzed by direct aspiration atomic absorption. Method
D3558-15C, the sample is acid digested and analyzed by graphite furnace
atomic absorption. The concentration of cobalt in the sample is
proportional to the amount of light absorbed during the analysis and is
determined in comparison to a standard curve. The changes mirror those
for the other metals methods. The proposed changes also clarify the
requirements for a multi-point calibration by discussing it in the
calibration section as well as the QC section of all three procedures.
The QC frequencies for method blank, CCV, CCB, matrix spike, and
duplicate analyses are now based on a laboratory-defined batch of up to
20 samples, as opposed to 10 samples previously.
    26. ASTM Method D3559-15 (A-D), lead, AA direct aspiration,
voltammetry, AA furnace. Method D3559-15A, the sample is acid digested
and analyzed by direct aspiration atomic absorption. Method D3559-15B,
the sample is acid digested, chelated and extracted. The extract is
analyzed by direct aspiration atomic absorption. Method D3559-15C, the
sample is acid digested and analyzed by differential pulse anodic
stripping voltametry. Method D3559-15D, the sample is digested with
nitric acid and analyzed by graphite furnace atomic absorption. The
changes mirror those for the other metals methods. The proposed changes
also clarify the requirements for a multi-point calibration by
discussing it in the calibration section as well as the QC section of
all three procedures. It also adds a new section with the QC
requirements to the direct AA procedure that was already present in the
AA furnace portion of this procedure (D3559-15 [D]).
    27. ASTM Method D3590-17 (A, B), total Kjeldahl nitrogen, manual
digestion and distillation or gas diffusion; semi-automated block
digester colorimetric (distillation not required). Method D3590-17A,
the sample is chemically processed to covert nitrogenous compounds to
ammonia, then distilled or subjected to a gas diffusion system which
releases the ammonia for analysis by colorimetry, titrimetry, or
potentiometry. Method D3590-17B, the digestion and distillation are
accomplished by a semi-automated system and the resulting ammonia is
determined by colorimetry of the salicylate/nitroprusside Berthelot
reaction product. This version changes the acceptance limit for the CCV
from 10% to 15% and adds a requirement for a CCB. Given that neither
the approved Standard Methods method for measuring ammonia after the
TKN digestion, nor the comparable EPA Method 350.1, include a CCV
requirement or an acceptance limit, the change of the acceptance limit
from 10% to 15% in the revised ASTM method represents a requirement
that is more stringent than that required in other approved procedures
and therefore is not an impediment to its approval.
    28. ASTM Method D3645-15, beryllium (A, B), AA direct aspiration AA
furnace. Method D3645-15A, the sample is acid digested and analyzed by
direct aspiration atomic absorption. Method D3645-15B, the sample is
digested with nitric acid and analyzed by graphite furnace atomic
absorption. This version adds specifications for filter paper. The
proposed changes also clarify the requirements for a three-point
calibration by discussing it in the calibration section as well as the
QC section of both procedures. It also adds a new section with the QC
requirements to the direct aspiration AA procedure that was already
present in the AA furnace portion of this procedure (D3645-15B).
    29. ASTM Method D3859-15 (A, B), selenium, AA gaseous hydride, AA
furnace. In Method D3859-15A, the selenium in the sample is converted
to gaseous selenium hydride, which is then analyzed by flame atomic
absorption. Method D3859-15B, the selenium in the sample is converted
to gaseous selenium hydride and analyzed by graphite furnace atomic
absorption. The changes to the gaseous hydride portion of the method
clarify the requirement for a 6-point calibration curve by discussing
it in the calibration section as well as the QC section. The version
adds an updated discussion of block digesters. The QC frequencies for
method blank, CCV, CCB, matrix spike, and duplicate analyses are now
based on a laboratory-defined batch, as opposed to an otherwise
undefined ``batch.'' The GFAA portion contains similar editorial and
technical changes. Technical changes also include specifications for
filter paper. The calibration requirement for three standards has been
clarified by discussing it in the calibration section as well as the QC
section.
    30. ASTM Method D3867-16 (A, B) nitrate-nitrite, nitrite and
nitrate; automated cadmium reduction, manual cadmium reduction, bypass
cadmium reduction and subtraction. The combination of nitrate and
nitrite in the sample is determined by reducing the nitrate to nitrite
using a cadmium-copper column, diazotizing and analyzing in either a
manual or automated spectrophotometric system. A second aliquot of the
sample can be analyzed without use of the cadmium reduction column to
determine the concentration of nitrate by difference. The changes add
more detailed QC requirements, including specifically calling out the
laboratory control sample (LCS), method blank, and matrix spike
analyses. The 2016 version adds specifications for filter paper. It
also changes the LCS frequency from 10% of samples to once per batch
(up to 20) and sets the CCB and CCV frequencies at 10%.
    31. ASTM Method D4190-15, dissolved elements and total recoverable
elements, direct current plasma. The concentrations of various metal
elements are determined by acidifying an aliquot of the sample and
analyzing it by direct current plasma spectrometry, monitoring a
specific wavelength of light for each element. There is one change that
adds a requirement to run at least four calibration standards for all
metals, as opposed to running four standards for only lithium to
demonstrate linearity.
    32. ASTM Method D4282-15, free cyanide, manual micro-diffusion and
colorimetry. The sample is treated and allow for free cyanide diffuse
into a sodium hydroxide solution. An aliquot of that solution is
treated to form a colored product that is measured with a
spectrophotometer at 580 nm. There are no procedural changes.
    33. ASTM Method D4327-17, inorganic anions (fluoride, bromide,
chloride, nitrite, nitrate, orthophosphate, and sulfate), ion
chromatography. An aliquot of the sample in injected into an ion
chromatograph equipped with an anion exchange column and a conductivity
detector. The anions are identified based on their retention times and
concentrations are determined by comparison to a standard curve.
Changes include updating the equipment and reagent descriptions to

reflect more modern instrumentation, such as the use of hydroxide
eluents and eluent regeneration systems.
    34. ASTM Method D4382-18, barium, AA furnace. The sample is
digested with nitric acid and analyzed by graphite furnace atomic
absorption. The only procedural change is to the description of the hot
block digester equipment. The new version specifies the capability to
heat samples between 65 and 95 degrees C, instead of ``approximately 95
degrees C.'' That change recognizes the operational characteristics of
hot block digesters that will experience a temperature drop below 95
degrees when samples are added. This should not adversely affect use of
this method for barium.
    35. ASTM Method D4658-15, sulfide ion, ion selective electrode. The
sample is treated with a sulfide antioxidant buffer to create a highly
alkaline solution. Sulfide in the sample is measured potentiometrically
with an ion-selective electrode. There are no procedural changes.
    36. ASTM Method D4839-03 (Reapproved 2017), total organic carbon;
heated persulfate or UV persulfate oxidation. The sample is sparged
with an inert gas to remove dissolved inorganic carbon and then treated
with persulfate and either heat or UV radiation to convert organic
carbon to carbon dioxide. The carbon dioxide is measured with an infra-
red detector. There are no procedural changes.
    37. ASTM Method D5257-17, dissolved hexavalent chromium, ion
chromatography. The sample is filtered and buffered and an aliquot
injected into an ion chromatograph that separates hexavalent chromium
from other ions. The eluent from the chromatograph is treated with an
acidic solution of diphenylcarbohydrazide to form a violet-colored
product that is measured with a photometric detector at 530 nm. The
changes add a few additional warnings or recommendations.
    38. ASTM Method D5673-16, dissolved elements and total-recoverable
elements, ICP/MS. The sample is acid digested and analyzed by
inductively coupled plasma/mass spectrometry. Gold was added to the
list of target analytes. Some of the changes address the analysis of
gold.
    39. ASTM Method D6508-15, inorganic anions (fluoride, bromide,
chloride, nitrite, nitrate, orthophosphate, and sulfate), capillary ion
electrophoresis with indirect UV detection. An aliquot of the sample in
injected into a capillary ion electrophoresis instrument where the
anions are separated in an applied electric field through a fused
silica capillary. The analytes are detected by a UV detector and their
concentrations are determined by comparison to a standard curve. There
are no procedural changes.
    40. ASTM Method D6888-16, available cyanide, flow injection and
ligand exchange, followed by gas diffusion amperometry. An aliquot of
the sample is introduced into a flow injection analysis instrument,
where available cyanide is acidified to form hydrogen cyanide which
diffuses through a hydrophobic gas diffusion membrane into an alkaline
solution and is detected amperometrically with a silver electrode. This
version adds a new mixed ligand exchange reagent, but also retains the
original two ligand reagents that had to be mixed together during the
testing.
    41. ASTM Method D6919-17, inorganic alkali and alkaline earth
cations and ammonium (ammonium, calcium magnesium, potassium and
sodium), ion chromatography. An aliquot of the sample in injected into
an ion chromatograph equipped with a cation exchange column and a
conductivity detector. The cations are identified based on their
retention times and concentrations are determined by comparison to a
standard curve. There are no procedural changes.
    42. ASTM Method D7237-15 (A), free cyanide, flow injection,
followed by gas diffusion amperometry. An aliquot of the sample is
introduced into a flow injection analysis instrument, where it mixes
with a phosphate buffer to release hydrogen cyanide which diffuses
through a hydrophobic gas diffusion membrane into an alkaline solution
and is detected amperometrically with a silver electrode. There are a
few additions and changes to the newer version of note. The statement
of the applicable range of the method in Section 1.4 has been changed
at the low end, from 2 to 500 [micro]g/L to 5 to 500 [micro]g/L. New
information about interferences from floatation reagents has been added
to Section 6.3. New materials in Section 8 discuss alternative reagents
or concentrations.
    43. ASTM Method D7284-13 (Reapproved 2017), total cyanide, manual
distillation with MgCl2 followed by flow injection, gas
diffusion amperometry. The sample is distilled with acid and a
magnesium chloride catalyst to release cyanide to a sodium hydroxide
solution. An aliquot of the sodium hydroxide solution is introduced
into a flow injection analysis instrument, where it is acidified and
the hydrogen cyanide diffuses through a hydrophobic gas diffusion
membrane into an alkaline solution and is detected amperometrically
with a silver electrode. There are no procedural changes.
    44. ASTM Method D7511-12 (Reapproved 2017), total cyanide,
segmented flow injection, in-line ultraviolet digestion, followed by
gas diffusion amperometry. The sample is introduced into a segmented
flow injection analysis instrument, where UV light releases cyanide
from cyanide complexes. The sample is then acidified in the instrument
and the produced cyanide gas is detected amperometrically with a silver
electrode. There are no procedural changes.
    45. ASTM Method D7573-09 (Reapproved 2017), total organic carbon,
combustion. The sample is sparged with an inert gas to remove dissolved
inorganic carbon, acidified, and then combusted at high temperature
convert organic carbon to carbon dioxide. The carbon dioxide is
measured with an infra-red detector. There are no procedural changes.
    The EPA proposes the following changes to Table IC at 40 CFR part
136:
    1. ASTM Method D7065-17, nonylphenol, bisphenol A, p-tert-
octylphenol, nonylphenol monoethoxylate, nonylphenol diethoxylate, gas
chromatography/mass spectrometry (GC/MS). The sample is extracted with
methylene chloride and the extract is injected into a gas
chromatograph-mass spectrometer. The target analytes are identified by
retention time and mass spectra and quantified using internal standards
and a calibration curve. There are a large number of editorial and
structural changes in the document. A new QC section has been added.

F. Changes to 40 CFR 136.3 To Include a New ASTM Method Based on
Previously Approved Technologies

    The EPA is proposing these changes based on the National Technology
Transfer and Advancement Act of 1995 (NTTAA), Public Law 104-113, which
states that federal agencies and departments shall use technical
standards developed or adopted by the VCSBs if compliance would not be
inconsistent with applicable law or otherwise impracticable. This
method submitted by ASTM is consistent with other already approved
methods.
    1. The EPA proposes to add ASTM Method D7781-14 to Table IB for
nitrate-nitrite, nitrite (bypass the enzymatic reduction step) and
nitrate by subtraction. Nitrate is reduced to nitrite by an enzymatic
reaction. The nitrite is diazotized to yield an azo dye which is

measured colorimetrically. The enzyme reduction step may be by-passed
for measurement of nitrite singly. The value obtained for nitrite may
be subtracted from the value obtained for combined nitrate-nitrite to
calculate the concentration of nitrate. This method is similar to the
currently approved NECi Method N07-0003, USGS Method I-2547-11, and
USGS Method I-2548-11.

G. Changes to 40 CFR 136.3 To Include New United States Geological
Survey (USGS) Inorganic Methods Based on Previously Approved
Technologies

    1. The EPA proposes to add USGS Method I-2057-85 titled ``Anions,
ion-exchange chromatographic, automated,'' to Table IB for bromide.
Method I-2057-85 is an ion chromatography method that lists several
target analytes: bromide, chloride, fluoride, nitrate, nitrite,
orthophosphate, and sulfate. These are the same target analytes found
in EPA Methods 300.0 (Part A) and 300.1 (Part A). Both EPA methods are
approved in 40 CFR part 136 for the target analytes listed in the
methods. USGS Method I-2057-85 is similar to EPA Method 300.0, in that
it uses ion chromatography with a sodium bicarbonate/sodium carbonate
eluent and has the same target analyte list. The two methods specify
different columns and eluent concentrations, but rely on essentially
the same underlying chemistry and determinative technique as other ion
chromatography methods approved at 40 CFR part 136 for measurement of
bromide. That is, the sample is introduced into an ion chromatograph.
The anions of interest are separated and measured, using a system
comprised of a guard column, analytical column, suppressor device, and
conductivity detector.
    2. The EPA proposes to add USGS Method I-2522-90 titled ``Nitrogen,
ammonia, colorimetry, salicylate-hypochlorite, automated-segmented
flow'' to Table IB for ammonia. USGS Method I-2522-90 uses the same
underlying chemistry and determinative technique as other methods
approved at 40 CFR part 136 for measurement of ammonia. The method is
similar to other approved methods, such as EPA Method 350.1, Standard
Methods Method 4500-NH3 G, and USGS Method I-4523-85, which rely on the
Berthelot reaction. USGS Method I-2522-90 uses a modified version of
the Berthelot reaction in which salicylate and hypochlorite react with
ammonia in the presence of ferricyanide ions to form the salicylic
analog of indophenol blue dye. The resulting color is directly
proportional to the concentration of ammonia present and is measured
using automated spectrophotometry. This is a well-documented
modification to the Berthelot reaction used in EPA Method 351 and is
specifically allowed in Table IB.
    3. The EPA proposes to add USGS Method I-2540-90 titled ``Nitrogen,
nitrite, colorimetry, diazotization, automated-segmented flow'' to
Table IB for nitrite. USGS Method I-2540-90 employs the same underlying
chemistry and determinative technique as other methods approved at 40
CFR part 136 for measurement of nitrite. The method is similar to other
methods approved at 40 CFR part 136 for measurement of nitrite,
including USGS Method I-4540-85, which uses an automated-segmented flow
analyzer (Technicon AA II). Method I-2540-90, nitrite reacts with
sulfanilamide under acidic conditions to form a diazo compound which is
coupled with N-1-naphthylethylenediamine dihydrochloride to form a red
compound, the absorbance of which is measured using an automated-
segmented flow, spectrophotometry.
    4. The EPA proposes to add USGS Method I-2601-90 titled
``Phosphorus, orthophosphate, colorimetry, phosphomolybdate, automated-
segmented flow'' to Table IB for orthophosphate. USGS Method I-2601-90
employs the same underlying chemistry and determinative technique as
other methods approved in 40 CFR part 136 for measurement of
orthophosphate. Orthophosphate reacts with ammonium molybdate in acidic
solution to form phosphomolybdic acid, which upon reduction with
ascorbic acid produces an intensely blue complex the absorbance of
which is measured using automated spectrophotometry. Antimony potassium
tartrate is added to increase the rate of reduction. The method is
similar to other approved methods, such as USGS Method I-4601-85 which
uses an automated-segmented flow analyzer (Technicon AA II). The
submitted USGS Method I-2601-90 also uses an automated-segmented flow
analyzer (Alpkem rapid flow analyzer). It should be noted that the
approved USGS Method I-4601-85 has two parameter codes listed:
    a. Phosphorus, orthophosphate, dissolved, I-2601-85 (mg/L as P);
    b. Phosphorus, orthophosphate, total, I-4601-85 (mg/L as P).
    Although USGS Method I-4601-85 is listed in Table IB, samples to be
used for measurement of orthophosphate are to be filtered upon
collection per Table II. Therefore, the correct parameter code listed
for the method should have been I-2601-85. I-2601-90 is just an updated
version of that method (parameter code). In Section 3--Interferences,
USGS Method I-2601-85 states: ``Because as phosphorus is easily
adsorbed on sediment, the orthophosphate recovered from the supernatant
solution above a water-suspended sediment after some time has elapsed
may be less than the orthophosphate that would have been determined in
the filtrate from a sample filtered at the time of collection. The
amount recovered may also depend on the type of sediment (clay, sand,
etc.).''
    5. The EPA proposes USGS Method I-4472-97 titled ``Metals, Acid
Digestion, Whole-Water Recoverable, inductively coupled plasma-mass
spectrometry'' to be added to Table IB for certain metals by ICP/MS.
USGS Method I-4472-97 is an ICP/MS method that was previously listed
under the same method number as the USGS ICP/AES Method I-4471-97 and
was split out and assigned a unique method number by USGS in 2003. The
EPA proposes to add this to Table IB on the line for ICP/MS and replace
USGS Method I-4471-97 as an approved method for measurement of the
following 16 elements: aluminum, antimony, barium, beryllium, cadmium,
chromium, cobalt, copper, lead, manganese, molybdenum, nickel,
selenium, silver, thallium and zinc. USGS Method I-4472-97 relies on
the same underlying chemistry and determinative technique as other ICP/
MS methods approved at 40 CFR part 136 for measurement of the same 16
elements (e.g., EPA Method 200.8 and Standard Methods Method 3125 B)
where analytes in the sample are solubilized by gentle refluxing with
acids and then measured using inductively coupled plasma-mass
spectrometry.

H. Changes to 40 CFR 136.3 To Include New United States Geological
Survey (USGS) Organic Methods Based on Previously Approved Technologies

    1. The EPA proposes to add USGS Method O-4127-96 titled
``Determination of 86 Volatile Organic Compounds in Water by Gas
Chromatography/Mass Spectrometry, Including Detections Less Than
Reporting Limits'' to Table IC for certain organic compounds. USGS
Method O-4127-96 relies on the same underlying chemistry and
determinative technique as other methods approved at 40 CFR part 136
for measurement of the analytes for which the method is being proposed.
Volatile organic compounds are extracted by purging with Helium,
collecting onto a sorbent trap, thermally desorbed, separated by a gas
chromatographic capillary column, and finally determined by a full-scan

quadrupole mass spectrometer. Compound identification is confirmed by
the gas chromatographic retention time and by the resultant mass
spectrum, typically identified by three unique ions.
    2. The EPA Proposes to add USGS Method O-4436-16 titled
``Determination of Heat Purgeable and Ambient Purgeable Volatile
Organic Compounds in Water by Gas Chromatography/Mass Spectrometry'' to
Table IC for certain organic compounds. USGS Method O-4436-16 relies on
the same underlying chemistry and determinative technique as other
methods approved at 40 CFR part 136 for measurement of the analytes for
which the method is being proposed. Volatile organic compounds are
extracted from a water sample and compounds are trapped in a tube
containing a suitable sorbent materials and then thermally desorbed
into a capillary gas chromatographic column interfaced to a mass
spectrometer system. Selected compounds are identified by using strict
qualification criteria, which include analyzing standard reference
materials and comparing retention times and relative ratios of the mass
spectra. Compounds are quantitated using internal standard procedures.

I. Changes to 40 CFR 136.3 To Include Alternate Test Procedures (ATPs)

    To promote method innovation, the EPA maintains a program that
allows method developers to apply for EPA review and potential approval
of an alternative method to an existing approved method. This ATP
program is described for CWA applications at 40 CFR 136.4 and 136.5.
The EPA is proposing three ATPs for nationwide use. Based on the EPA's
review, the performance of these ATPs is equally effective as other
methods already approved for measurement. The ATP applicants supplied
EPA with study reports that contain the data from their validation
studies. These study reports and the letters documenting EPA's review
are contained as supporting documents within the docket for this
proposed rule. These proposed new methods include: FIAlab Method 100,
``Determination of Inorganic Ammonia by Continuous Flow Gas Diffusion
and Fluorescence Detector Analysis,'' MACHEREY-NAGEL GmbH and Co.
Method 036/038 NANOCOLOR[supreg] COD LR/HR, ``Spectrophotometric
Measurement of Chemical Oxygen Demand in Water and Wastewater,'' and
Micrology Laboratories, LLC. KwikCountTM EC Medium
Escherichia coli (E. coli) enzyme substrate test, ``Rapid Detection of
E. coli in Beach Water by KwikCountTM EC Membrane
Filtration.'' Descriptions of these new methods proposed for approval
are as follows:
    1. FIAlab Instruments, Inc. Method 100, ``Determination of
Inorganic Ammonia by Continuous Flow Gas Diffusion and Fluorescence
Detector Analysis,'' dated April 4, 2018 (FIAlab Instruments, Inc.
2018a). FIAlab Method 100 uses automated flow injection analysis with
gas diffusion and fluorescence detector analysis to determine
concentrations of ammonia in wastewater, ambient water, and Kjeldahl
digestates. The method involves the following steps:
     The sample is introduced to the analyzer where it is made
alkaline with sodium hydroxide;
     Ammonia is separated from the sample matrix by passage
through a gas diffusion cell;
     After separation in the gas diffusion cell, ammonia is
reacted with o-phthalaldehyde to form a fluorescent compound;
     The reaction product is detected by a fluorimeter and the
response is directly proportional to the concentration of ammonia in
the sample.
    FIAlab Method 100 can be obtained from FIAlab Instruments, Inc.,
334 2151 N Northlake Way, Seattle, WA 98103. Telephone:<PHONE_NUMBER>.
    2. MACHEREY-NAGEL GmbH and Co. Method 036/038 NANOCOLOR[supreg] COD
LR/HR, ``Spectrophotometric Measurement of Chemical Oxygen Demand in
Water and Wastewater,'' Revision 1.5, dated, May 2018 (MACHEREY-NAGEL
GmbH and Co. 2018a). MACHEREY-NAGEL Method 036/038 NANOCOLOR[supreg]
COD LR/HR is a manual method that uses spectrophotometry to measure
chemical oxygen demand in wastewater. The method involves the following
steps:
     Chemical Oxygen Demand (COD) is defined as the mg of
oxygen (O2) consumed per liter of sample following
dichromate and sulfuric acid digestion;
     A sample is heated for two hours with a strong oxidizing
agent, potassium dichromate. Oxidizable organic compounds react,
reducing the dichromate ion
(Cr2O7\2\-) to the green chromic ion
(Cr\3+\);
     When the COD LR 150 test kit is used, the amount of Cr\6+\
remaining after digestion is determined;
     When the COD HR 1500 test kit is used, the amount of
Cr\3+\ produced is determined.
    MACHEREY-NAGEL GmbH and Co. Method 036/038 NANOCOLOR[supreg] COD
LR/HR, can be obtained from MACHEREY-NAGEL GmbH and Co., 2850 Emrick
Blvd., Bethlehem, PA 18020. Telephone:<PHONE_NUMBER>.
    3. Micrology Laboratories LLC. KwikCountTM EC Medium E.
coli enzyme substrate test, ``Rapid Detection of E. coli in Beach Water
by KwikCountTM EC Membrane Filtration'' uses a membrane
filtration procedure for rapid detection and enumeration of E. coli in
ambient water. The method involves the following steps:
     A water sample is filtered through a 0.45-[mu]m pore size,
47-mm diameter membrane filter;
     The filter is then placed into a 50-mm plate containing an
absorbent pad containing KwikCountTM EC broth;
     Plates are incubated at 41  0.5 [deg]C for 8-
10 hr. The plates are then viewed in the dark using a long-wave UV
light and fluorescent colonies are counted as E. coli.
    The KwikCountTM EC Medium E. coli enzyme substrate test
can be obtained from Micrology Laboratories, LLC, 1303 Eisenhower
Drive, Goshen, IN 46526. Telephone:<PHONE_NUMBER>.

J. Changes to 40 CFR 136.3, Tables IA, IB, and IH

    The EPA is proposing the following changes to 40 CFR 136.3, Tables
IA and IH:
    1. Table IA: Moving Colilert-18 from Parameter #1 Coliform (fecal),
number per 100 mL or number per gram dry weight, to Parameter #2
Coliform (fecal), (number per 100 mL), to eliminate confusion as to
whether it is approved for sewage sludge in addition to wastewater.
    2. Table IA: Adding E. coli, number per 100 mL--MF, two-step,
Standard Methods Method 9222 B/9222 I, to the table along with footnote
31 ``Subject coliform positive samples determined by 9222 B-2015 or
other membrane filter procedure to 9222 I-2015 using NA-MUG media.''
The method was inadvertently omitted from Table IA when Table IA was
split into two tables (IA and IH) in an earlier rulemaking; the
addition corrects that error.
    3. Table IA: Revising Parameter #2 Coliform (fecal), deleting ``in
presence of chlorine,'' number per 100 mL. The phrase ``in the presence
of chlorine'' caused confusion because the methods cited were the same
for the analyte/matrix combination that did not state ``in the presence
of chlorine.'' The approved methods did not change.
    4. Table IA: Deleting Parameter #4 Coliform (total) in presence of
chlorine, number per 100 mL. Except for ``MF with enrichment,'' all the
methods were duplicative (e.g., Parameters #3 and #4).

No approved methods for coliform (total) were removed from Table IA.
    5. Table IH: Deleting Parameters #2 Coliform (fecal) in presence of
chlorine, number per 100 mL and #4 Coliform (total) in presence of
chlorine, number per 100 mL. Except for ``MF with enrichment'' for
coliform (total), all the methods were duplicative (e.g., Parameters #1
and #2). In addition to the methods being duplicative, Table IH is for
ambient water which would not be expected to contain chlorine. No
approved methods for coliform (fecal) or coliform (total) were removed
from Table IH. The remaining parameters are renumbered.
    6. Tables IA and IH: Revising footnote 13 to Table IA and footnote
12 to Table IH as follows ``These tests are collectively known as
defined enzyme substrate tests.'' The remaining text, ``where, for
example, a substrate is used to detect the enzyme [beta]-glucuronidase
produced by E. coli'' has been deleted because the example has caused
some confusion to stakeholders.
    7. Tables IA and IH: Adding Quanti-Tray[supreg]/2000 as an option
to footnotes 13 (IH), 15 (IH), 16 (IA) and 18 (IA). The addition of
Quanti-Tray[supreg]/2000 is to address matrices with high bacterial
concentrations and to ensure Tables IA and IH are accurate and
consistent.
    8. Tables IA and IH: Adding footnote 30 to Table IA and footnote 27
to Table IH to specify a verification procedure. The footnotes contain
the following language: ``On a monthly basis, at least ten sheen
colonies from positive samples must be verified using Lauryl Tryptose
Broth and brilliant green lactose bile broth, followed by count
adjustment based on these results; and representative non-sheen
colonies should be verified using Lauryl Tryptose Broth. Where
possible, verifications should be done from randomized sample
sources.'' Adding the footnotes address the change in Standard Methods
Method 9222 B-2015 that stated that five typical and five atypical
colonies should be verified per membrane, which could be burdensome to
laboratories analyzing samples other than drinking water. In most
cases, analysis of ambient waters and wastewaters could result in
multiple plates per sample with typical and atypical colonies, whereas
drinking water analyses would seldom result in any typical or atypical
colonies. In addition, the language in footnotes 29 (IA) and 26 (IH),
was revised as follows ``the medium'' was replaced with ``positive
samples'' for clarity and consistency.
    9. Tables IA and IH: Adding footnote 32 to Table IA and footnote 30
to Table IH. The footnotes contain the following language
``Verification of colonies by incubation of BHI agar at 10
0.5 [deg]C for 48  3 h is optional.'' As per the Errata to
the 23rd Edition of Standard Methods for the Examination of Water &
Wastewater, ``Growth on a BHI agar plate incubated at 10
0.5 [deg]C for 48  3 h is further verification that the
colony belongs to the genus Enterococcus.''
    10. Table IH: Deleting ``or number per gram dry weight'' from
Parameter #1. Table IH is specifically for ambient waters, which does
not require reporting results on a per gram dry weight basis.
    11. Table IH: Adding the Alternate Test Procedure
KwikCountTM EC for E. coli, number per 100 mL under
``Other.''
    12. Table IH: Adding EPA Method 1623.1 for Parameters 6 and 7. EPA
Method 1623.1 includes updated acceptance criteria for IPR, OPR, and
MS/MSD, and clarifications and revisions based on the use of EPA Method
1623 and technical support questions over the past 19 years. Both
methods 1623 and 1623.1 will be listed as approved in the MUR because
use of either method is acceptable.
    13. Table IH: Deleting footnote 5, ``Because the MF technique
usually yields low and variable recovery from chlorinated wastewaters,
the Most Probable Number method will be required to resolve any
controversies.'' Table IH is specifically for ambient waters, so the
footnote is not applicable. The remaining footnotes are renumbered
accordingly.
    14. Table IH: Revising footnote 20, to reference only EPA Method
1604. The literature reference was deleted from the footnote because it
resulted in confusion as to whether EPA Method 1604 provided all the
necessary information required by stakeholders to conduct analyses of
ambient waters under the CWA.

K. Changes to Table II at 40 CFR 136.3(e) to Required Containers,
Preservation Techniques, and Holding Times

    The EPA is proposing to update footnote 6 to the preservation and
holding time requirements for cyanide to cite the latest version of
ASTM method D7365-09a that was reapproved in 2015. The recommended
sampling and preservation procedures in the ASTM method have not
changed since 2009, but the change to footnote 6 will simplify
identification of the current method that is available from ASTM
International.
    The EPA is proposing to add footnote 9 to the preservation and
holding time requirements to the purgeable halocarbons entry. This will
allow the flexibility to collect a single sample with no acidification
to be used for analysis of both purgeable halocarbons and purgeable
aromatic hydrocarbons within seven days of collection, or to collect a
single sample with acidification to be used for analysis of both
purgeable halocarbons (except 2-CEVE) and purgeable aromatic
hydrocarbons within the 14-day maximum holding time specified in Table
II for both classes of compounds. The added flexibility is consistent
with historical requirements for preservation in 40 CFR part 136 and
holding time requirements in other EPA program methods, such as the SW-
846 methods in the Office of Land and Emergency Management. This is
part of the EPA's ongoing effort to harmonize methods between EPA
programs, as requested by the Environmental Laboratory Advisory Board
(ELAB).
    Footnote 9 to Table II states: ``If the sample is not adjusted to
pH 2, then the sample must be analyzed within seven days of sampling.''

L. Changes to 40 CFR 136.6 Method Modifications and Analytical
Requirements

    In response to requests from ELAB and the Independent Laboratories
Institute (ILI), the EPA is proposing to add a new paragraph
(b)(4)(xviii) to 40 CFR 136.6 that explicitly allows the use of closed-
vessel microwave digestion as a modification to the approved metals
digestion procedure that does not require prior approval. Microwave
digestion has the same fundamental chemistry as a hot plate digestion,
both the microwave and hot plate serve the same function as heat
sources.

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Review and
Executive Order 13563: Improving Regulation and Regulatory Review

    This rule is not a significant regulatory action and was therefore
not submitted to the Office of Management and Budget (OMB) for
interagency review under this E.O.

B. Paperwork Reduction Act

    This action does not impose an information collection burden under
the Paperwork Reduction Act. This rule does not impose any information
collection, reporting, or recordkeeping requirements. This proposal
would merely add or revise CWA test procedures.

C. Regulatory Flexibility Act

    I certify that this action would not have a significant economic
impact on a substantial number of small entities under the Regulatory
Flexibility Act. This action will not impose any requirements on small
entities. This action would approve new and revised versions of CWA
testing procedures. Generally, these changes would have a positive
impact on small entities by increasing method flexibility, thereby
allowing entities to reduce costs by choosing more cost-effective
methods. In general, the EPA expects the proposed revisions would lead
to few, if any, increased costs. As explained previously, most of the
proposed changes clarify or improve the instructions in the method,
update the technology used in the method, improve the QC instructions,
make editorial corrections, or reflect the most recent approval year of
an already approved method. In some cases, the proposal would add
alternatives to currently approved methods for a particular analyte
(e.g., Method N07-0003 for Nitrate Reductase Nitrate-Nitrogen
Analysis). Because these methods would be alternatives rather than
requirements, there are no direct costs associated with this proposal.
The EPA proposes methods that would be incorporated by reference. If a
permittee elected to use these methods, they could incur a small cost
associated with obtaining these methods from the listed sources. See
Section IV.B.

D. Unfunded Mandates Reform Act

    This action does not contain any unfunded mandate as described in
the Unfunded Mandates Reform Act, 2 U.S.C. 1531-1538, and does not
significantly or uniquely affect small governments. The action imposes
no enforceable duty on any state, local or tribal governments or the
private sector.

E. Executive Order 13132: Federalism

    This proposed rule does not have federalism implications. It will
not have substantial direct effects on the states, on the relationship
between the national government and the states, or on the distribution
of power and responsibilities among the various levels of government.

F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

    This proposed rule does not have tribal implications as specified
in Executive Order 13175. This rule would merely approve new and
revised versions of test procedures. The EPA does not expect the
proposal would lead to any costs to any tribal governments, and if
incurred, projects they would be minimal. Thus, Executive Order 13175
does not apply to this action.

G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks

    The EPA interprets Executive Order 13045 as applying only to those
regulatory actions that concern environmental health or safety risks
that the EPA has reason to believe may disproportionately affect
children, per the definition of ``covered regulatory action'' in
section 2-202 of the Executive Order. This action is not subject to
Executive Order 13045 because it does not concern an environmental
health risk or safety risk.

H. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use

    This action is not subject to Executive Order 13211 because it is
not a significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act of 1995

    This action involves technical standards. The EPA proposes to
approve the use of technical standards developed and recommended by the
Standard Methods Committee and ASTM International for use in compliance
monitoring where the EPA determined that those standards meet the needs
of CWA programs. As described above, this proposal is consistent with
the NTTAA.

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

    The EPA believes the human health or environmental risk addressed
by this action will not have potential disproportionately high and
adverse human health or environmental effects on minority, low-income
or indigenous populations.

List of Subjects in 40 CFR Part 136

    Environmental protection, Incorporation by reference, Reporting and
recordkeeping requirements, Test procedures, Water pollution control.

    Dated: June 11, 2019.
Andrew R. Wheeler,
Administrator.

    For the reasons set out in the preamble, title 40, chapter I of the
Code of Federal Regulations is proposed to be amended as follows:

PART 136--GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS
OF POLLUTANTS

0
1. The authority citation for part 136 continues to read as follows:

    Authority:  Secs. 301, 304(h), 307 and 501(a), Pub. L. 95-217,
91 Stat. 1566, et seq. (33 U.S.C. 1251, et seq.) (the Federal Water
Pollution Control Act Amendments of 1972 as amended by the Clean
Water Act of 1977).

0
2. Amend Sec.  136.3 by:
0
a. In paragraph (a), seventh sentence, removing the word ``year'' and
adding in its place the word ``date'' in its place, and removing from
the last sentence the text ``(paragraph (c) of this section, in Sec.
136.5(a) through (d) or 40 CFR 401.13)'' and adding in its place the
text ``paragraph (c) of this section, Sec.  136.5(a) through (d) or 40
CFR 401.13,'' respectively;
0
b. Revising tables IA, IB, IC, and IH;
0
c. Revising paragraph (b) by:
0
i. Revising the introductory text; paragraph (b)(8) introductory text,
and paragraphs (b)(8)(ix) through (b)(xv);
0
ii. Adding paragraph (b)(8)(xvi);
0
iii. Revising paragraphs (b)(10)(xiv), (b)(10)(xxxix), (b)(10)(xliv),
(b)(10)(xlvi), (b)(10)(lii), (b)(10)(liv), (b)(10)(lxvii),
(b)(10)(lxviii), (b)(10)(lxix), (b)(10)(lxx), b)(15)(v), (b)(15)(vi),
(b)(15)(viii) through (xiii), (b)(15)(xv) through (xix), (b)(15)(xxi)
through (xxvi), (b)(15)(xxxi), (b)(15)(xxxiv) and (xxxv),
(b)(15)(xxxvii), (b)(15)(xxxix) through (xliii), (b)(15)(xlv) through
(l), (b)(15)(lii), (b)(15)(liv) and (b)(15)(lv), (b)(15)(lviii),
(b)(15)(lxi) through (lxvi), and (b)(15)(lxviii) through (lxix); and
0
iv. Adding paragraph (b)(15)(lxx);
0
v. Redesignating paragraphs (b)(25) through (b)(36) as paragraphs
(b)(28) through (b)(39);
0
vi. Redesignating paragraphs (b)(19) through (24) as paragraphs (b)(20)
through (25);
0
vii. Adding new paragraphs (b)(19), (26), and (27); and
0
viii. Revising the newly redesignated paragraphs (b)(38)(ii) through
(xxi);
0
ix. Adding paragraphs (b)(38)(xxii) and (xxiii); and
0
c. Revising paragraph (e) Table II.
    The revisions and additions read as follows:

Sec.  136.3   Identification of test procedures.

* * * * *

                                     Table IA--List of Approved Biological Methods for Wastewater and Sewage Sludge
--------------------------------------------------------------------------------------------------------------------------------------------------------
        Parameter and units                 Method \1\                   EPA              Standard methods      AOAC, ASTM, USGS            Other
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Bacteria
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Coliform (fecal), number per     Most Probable Number        p. 132,\3\ 1680,11 15  9221 E-2014..........
 100 mL or number per gram dry       (MPN), 5 tube, 3            1681,11 20.
 weight.                             dilution, or.
                                    Membrane filter (MF) 2 5,   p. 124 \3\...........  9222 D-2015 \29\.....  B-0050-85 \4\.......
                                     single step.
2. Coliform (fecal), number per     MPN, 5 tube, 3 dilution,    p. 132 \3\...........  9221 E-2014; 9221 F.2-
 100 mL.                             or.                                                2014 \33\.
                                    Multiple tube/multiple      .....................  .....................  ....................  Colilert-
                                     well, or.                                                                                18[supreg].13 18 28
                                    MF2 5, single step \5\....  p. 124 \3\...........  9222 D-2015 \29\.....
3. Coliform (total), number per     MPN, 5 tube, 3 dilution,    p. 114 \3\...........  9221 B-2014..........
 100 mL.                             or.
                                    MF 2 5, single step or two  p. 108 \3\...........  9222 B-2015 \30\.....  B-0025-85 \4\.......
                                     step.
                                    MF 2 5, with enrichment...  p. 111 \3\...........  9222 (B+B.4e)-2015
                                                                                \30\.
4. E. coli, number per 100 mL.....  MPN 6 8 16 multiple tube,   .....................  9221 B.3-2014/9221 F-
                                     or.                                                2014 12 14 33.
                                    multiple tube/multiple      .....................  9223 B-2016 \13\.....  991.15 \10\.........  Colilert[supreg].13
                                     well, or.                                                                                18 Colilert-
                                                                                18[supreg].13 17 18
                                    MF 2 5 6 7 8, two step, or  .....................  9222 B-2015/9222 I-
                                                                                2015 \31\.
                                    Single step...............  1603 \21\............  .....................  ....................  m-
                                                                                ColiBlue24[supreg].
                                                                                \19\
5. Fecal streptococci, number per   MPN, 5 tube, 3 dilution,    p. 139 \3\...........  9230 B-2013..........
 100 mL.                             or.
                                    MF \2\, or................  p. 136 \3\...........  9230 C-2013 \32\.....  B-0055-85 \4\.......
                                    Plate count...............  p. 143 \3\...........
6. Enterococci, number per 100 mL.  MPN, 5 tube, 3 dilution,    p. 139 \3\...........  9230 B-2013..........
                                     or.
                                    MPN 6 8, multiple tube/     .....................  9230 D-2013..........  D6503-99 \9\........  Enterolert[supreg].
                                     multiple well, or.                                                                              13 23
                                    MF 2 5 6 7 8 single step    1600 \24\............  9230 C-2013 \32\.....
                                     or.
                                    Plate count...............  p. 143 \3\...........
7. Salmonella, number per gram dry  MPN multiple tube.........  1682 \22\............
 weight \11\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Aquatic Toxicity
--------------------------------------------------------------------------------------------------------------------------------------------------------
8. Toxicity, acute, fresh water     Ceriodaphnia dubia acute..  2002.0 \25\..........
 organisms, LC50, percent effluent.
                                    Daphnia puplex and Daphnia  2021.0 \25\..........
                                     magna acute.
                                    Fathead Minnow, Pimephales  2000.0 \25\..........
                                     promelas, and Bannerfin
                                     shiner, Cyprinella
                                     leedsi, acute.
                                    Rainbow Trout,              2019.0 \25\..........
                                     Oncorhynchus mykiss, and
                                     brook trout, Salvelinus
                                     fontinalis, acute.
9. Toxicity, acute, estuarine and   Mysid, Mysidopsis bahia,    2007.0 \25\..........
 marine organisms of the Atlantic    acute.
 Ocean and Gulf of Mexico, LC50,
 percent effluent.
                                    Sheepshead Minnow,          2004.0 \25\..........
                                     Cyprinodon variegatus,
                                     acute.
                                    Silverside, Menidia         2006.0 \25\..........
                                     beryllina, Menidia
                                     menidia, and Menidia
                                     peninsulae, acute.
10. Toxicity, chronic, fresh water  Fathead minnow, Pimephales  1000.0 \26\..........
 organisms, NOEC or IC25, percent    promelas, larval survival
 effluent.                           and growth.
                                    Fathead minnow, Pimephales  1001.0 \26\..........
                                     promelas, embryo-larval
                                     survival and
                                     teratogenicity.
                                    Daphnia, Ceriodaphnia       1002.0 \26\..........
                                     dubia, survival and
                                     reproduction.
                                    Green alga, Selenastrum     1003.0 \26\..........
                                     capricornutum, growth.
11. Toxicity, chronic, estuarine    Sheepshead minnow,          1004.0 \27\..........
 and marine organisms of the         Cyprinodon variegatus,
 Atlantic Ocean and Gulf of          larval survival and
 Mexico, NOEC or IC25, percent       growth.
 effluent.
                                    Sheepshead minnow,          1005.0 \27\..........
                                     Cyprinodon variegatus,
                                     embryo-larval survival
                                     and teratogenicity.
                                    Inland silverside, Menidia  1006.0 \27\..........
                                     beryllina, larval
                                     survival and growth.
                                    Mysid, Mysidopsis bahia,    1007.0 \27\..........
                                     survival, growth, and
                                     fecundity.
                                    Sea urchin, Arbacia         1008.0 \27\..........
                                     punctulata, fertilization.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table IA notes:
\1\ The method must be specified when results are reported.

\2\ A 0.45-[micro]m membrane filter (MF) or other pore size certified by the manufacturer to fully retain organisms to be cultivated and to be free of
  extractables which could interfere with their growth.
\3\ Microbiological Methods for Monitoring the Environment, Water and Wastes, EPA/600/8-78/017. 1978. US EPA.
\4\ U.S. Geological Survey Techniques of Water-Resource Investigations, Book 5, Laboratory Analysis, Chapter A4, Methods for Collection and Analysis of
  Aquatic Biological and Microbiological Samples. 1989. USGS.
\5\ Because the MF technique usually yields low and variable recovery from chlorinated wastewaters, the Most Probable Number method will be required to
  resolve any controversies.
\6\ Tests must be conducted to provide organism enumeration (density). Select the appropriate configuration of tubes/filtrations and dilutions/volumes
  to account for the quality, character, consistency, and anticipated organism density of the water sample.
\7\ When the MF method has been used previously to test waters with high turbidity, large numbers of noncoliform bacteria, or samples that may contain
  organisms stressed by chlorine, a parallel test should be conducted with a multiple-tube technique to demonstrate applicability and comparability of
  results.
\8\ To assess the comparability of results obtained with individual methods, it is suggested that side-by-side tests be conducted across seasons of the
  year with the water samples routinely tested in accordance with the most current Standard Methods for the Examination of Water and Wastewater or EPA
  alternate test procedure (ATP) guidelines.
\9\ Annual Book of ASTM Standards-Water and Environmental Technology, Section 11.02. 2000, 1999, 1996. ASTM International.
\10\ Official Methods of Analysis of AOAC International. 16th Edition, 4th Revision, 1998. AOAC International.
\11\ Recommended for enumeration of target organism in sewage sludge.
\12\ The multiple-tube fermentation test is used in 9221B.2-2014. Lactose broth may be used in lieu of lauryl tryptose broth (LTB), if at least 25
  parallel tests are conducted between this broth and LTB using the water samples normally tested, and this comparison demonstrates that the false-
  positive rate and false-negative rate for total coliform using lactose broth is less than 10 percent. No requirement exists to run the completed phase
  on 10 percent of all total coliform-positive tubes on a seasonal basis.
\13\ These tests are collectively known as defined enzyme substrate tests.
\14\ After prior enrichment in a presumptive medium for total coliform using 9221B.2-2014, all presumptive tubes or bottles showing any amount of gas,
  growth or acidity within 48 h  3 h of incubation shall be submitted to 9221F-2014. Commercially available EC-MUG media or EC media
  supplemented in the laboratory with 50 [micro]g/mL of MUG may be used.
\15\ Method 1680: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation Using Lauryl-Tryptose Broth (LTB) and EC Medium, EPA-821-R-
  14-009. September 2014. U.S. EPA.
\16\ Samples shall be enumerated by the multiple-tube or multiple-well procedure. Using multiple-tube procedures, employ an appropriate tube and
  dilution configuration of the sample as needed and report the Most Probable Number (MPN). Samples tested with Colilert[supreg] may be enumerated with
  the multiple-well procedures, Quanti-Tray[supreg] or Quanti-Tray[supreg]/2000 and the MPN calculated from the table provided by the manufacturer.
\17\ Colilert-18[supreg] is an optimized formulation of the Colilert[supreg] for the determination of total coliforms and E. coli that provides results
  within 18 h of incubation at 35[deg]C rather than the 24 h required for the Colilert[supreg] test and is recommended for marine water samples.
\18\ Descriptions of the Colilert[supreg], Colilert-18[supreg], Quanti-Tray[supreg], and Quanti-Tray[supreg]/2000 may be obtained from IDEXX
  Laboratories, Inc.
\19\ A description of the mColiBlue24[supreg] test is available from Hach Company.
\20\ Method 1681: Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation Using A-1 Medium, EPA-821-R-06-013. July 2006. U.S. EPA.
\21\ Method 1603: Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified Membrane-Thermotolerant Escherichia coli Agar (modified
  mTEC), EPA-821-R-14-010. September 2014. U.S. EPA.
\22\ Method 1682: Salmonella in Sewage Sludge (Biosolids) by Modified Semisolid Rappaport-Vassiliadis (MSRV) Medium, EPA-821-R-14-012. September 2014.
  U.S. EPA.
\23\ A description of the Enterolert[supreg] test may be obtained from IDEXX Laboratories Inc.
\24\ Method 1600: Enterococci in Water by Membrane Filtration Using membrane-Enterococcus Indoxyl-[beta]-D-Glucoside Agar (mEI), EPA-821-R-14-011.
  September 2014. U.S. EPA.
\25\ Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, EPA-821-R-02-012. Fifth Edition,
  October 2002. U.S. EPA.
\26\ Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, EPA-821-R-02-013. Fourth Edition,
  October 2002. U.S. EPA.
\27\ Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms, EPA-821-R-02-014. Third
  Edition, October 2002. U.S. EPA.
\28\ To use Colilert-18[supreg] to assay for fecal coliforms, the incubation temperature is 44.5  0.2 [deg]C, and a water bath incubator is
  used.
\29\ On a monthly basis, at least ten blue colonies from positive samples must be verified using Lauryl Tryptose Broth and EC broth, followed by count
  adjustment based on these results; and representative non-blue colonies should be verified using Lauryl Tryptose Broth. Where possible, verifications
  should be done from randomized sample sources.
\30\ On a monthly basis, at least ten sheen colonies from positive samples must be verified using lauryl tryptose broth and brilliant green lactose bile
  broth, followed by count adjustment based on these results; and representative non-sheen colonies should be verified using lauryl tryptose broth.
  Where possible, verifications should be done from randomized sample sources.
\31\ Subject coliform positive samples determined by 9222 B-2015 or other membrane filter procedure to 9222 I-2015 using NA-MUG media.
\32\ Verification of colonies by incubation of BHI agar at 10  0.5 [deg]C for 48  3 h is optional. As per the Errata to the 23rd
  Edition of Standard Methods for the Examination of Water and Wastewater ``Growth on a BHI agar plate incubated at 10  0.5 [deg]C for 48
   3 h is further verification that the colony belongs to the genus Enterococcus.''
\33\ 9221 F. 2-2014 This procedure allows for simultaneous detection of E. coli and thermotolerant coliforms by adding inverted vials to EC-MUG; the
  inverted vials collect gas produced by thermotolerant coliforms.

                                                  Table IB--List of Approved Inorganic Test Procedures
--------------------------------------------------------------------------------------------------------------------------------------------------------
             Parameter                   Methodology \58\              EPA \52\        Standard methods \84\          ASTM             USGS/AOAC/other
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Acidity, as CaCO3, mg/L........  Electrometric endpoint or   .....................  2310 B-2011..........  D1067-16............  I-1020-85.\2\
                                     phenolphthalein endpoint.
2. Alkalinity, as CaCO3, mg/L.....  Electrometric or            .....................  2320 B-2011..........  D1067-16............  973.43 \3\, I-1030-
                                     Colorimetric titration to                                                                       85.\2\
                                     pH 4.5, Manual.
                                    Automatic.................  310.2 (Rev. 1974) \1\  .....................  ....................  I-2030-85.\2\
3. Aluminum--Total,\4\ mg/L.......  Digestion \4\, followed by
                                     any of the following:
                                    AA direct aspiration \36\.  .....................  3111 D-2011 or 3111 E- ....................  I-3051-85.\2\
                                                                                2011.
                                    AA furnace................  .....................  3113 B-2010..........
                                    STGFAA....................  200.9, Rev. 2.2
                                                                 (1994).
                                    ICP/AES \36\..............  200.5, Rev 4.2 (2003)  3120 B-2011..........  D1976-12............  I-4471-97.\50\
                                                                 \68\; 200.7, Rev.
                                                                 4.4 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14 \3\, I-4472-
                                                                 (1994).                                                             97.\81\
                                    Direct Current Plasma       .....................  .....................  D4190-15............  See footnote.\34\
                                     (DCP) \36\.
                                    Colorimetric (Eriochrome    .....................  3500-Al B-2011.......
                                     cyanine R).
4. Ammonia (as N), mg/L...........  Manual distillation \6\ or  350.1, Rev. 2.0        4500-NH3 B-2011......  ....................  973.49.\3\
                                     gas diffusion (pH >11),     (1993).
                                     followed by any of the
                                     following:
                                    Nesslerization............  .....................  .....................  D1426-15 (A)........  973.49 \3\, I-3520-
                                                                                85.\2\
                                    Titration.................  .....................  4500-NH3 C-2011......
                                    Electrode.................  .....................  4500-NH3 D-2011 or E-  D1426-15 (B)........
                                                                                2011.

                                    Manual phenate,             .....................  4500-NH3 F-2011......  ....................  See footnote.\60\
                                     salicylate, or other
                                     substituted phenols in
                                     Berthelot reaction-based
                                     methods.
                                    Automated phenate,          350.1 \30\, Rev. 2.0   4500-NH3 G-2011......  ....................  I-4523-85 \2\, I-
                                     salicylate, or other        (1993).               4500-NH3 H-2011......                         2522-90.\80\
                                     substituted phenols in
                                     Berthelot reaction-based
                                     methods.
                                    Automated electrode.......  .....................  .....................  ....................  See footnote.\7\
                                    Ion Chromatography........  .....................  .....................  D6919-17............
                                    Automated gas diffusion,    .....................  .....................  ....................  Timberline Ammonia-
                                     followed by conductivity                                                                        001.\74\
                                     cell analysis.
                                    Automated gas diffusion     .....................  .....................  ....................  FIAlab100.\82\
                                     followed by fluorescence
                                     detector analysis.
5. Antimony--Total,\4\ mg/L.......  Digestion \4\, followed by
                                     any of the following:
                                    AA direct aspiration \36\.  .....................  3111 B-2011..........
                                    AA furnace................  .....................  3113 B-2010..........
                                    STGFAA....................  200.9, Rev. 2.2
                                                                 (1994).
                                    ICP/AES \36\..............  200.5, Rev 4.2 (2003)  3120 B-2011..........  D1976-12............
                                                                 \68\; 200.7, Rev.
                                                                 4.4 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14 \3\, I-4472-
                                                                 (1994).                                                             97.\81\
6. Arsenic-Total,\4\ mg/L.........  Digestion \4\, followed by  206.5 (Issued 1978)
                                     any of the following:.      \1\.
                                    AA gaseous hydride........  .....................  3114 B-2011 or 3114 C- D2972-15 (B)........  I-3062-85.\2\
                                                                                2011.
                                    AA furnace................  .....................  3113 B-2010..........  D2972-15 (C)........  I-4063-98.\49\
                                    STGFAA....................  200.9, Rev. 2.2
                                                                 (1994).
                                    ICP/AES \36\..............  200.5, Rev 4.2 (2003)  3120 B-2011..........  D1976-12............
                                                                 \68\; 200.7, Rev.
                                                                 4.4 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14 \3\, I-4020-
                                                                 (1994).                                                             05.\70\
                                    Colorimetric (SDDC).......  .....................  3500-As B-2011.......  D2972-15 (A)........  I-3060-85.\2\
7. Barium-Total,\4\ mg/L..........  Digestion \4\, followed by
                                     any of the following:
                                    AA direct aspiration \36\.  .....................  3111 D-2011..........  ....................  I-3084-85.\2\
                                    AA furnace................  .....................  3113 B-2010..........  D4382-18............
                                    ICP/AES \36\..............  200.5, Rev 4.2 (2003)  3120 B-2011..........  ....................  I-4471-97.\50\
                                                                 \68\; 200.7, Rev.
                                                                 4.4 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14 \3\, I-4472-
                                                                 (1994).                                                             97.\81\
                                    DCP \36\..................  .....................  .....................  ....................  See footnote.\34\
8. Beryllium--Total,\4\ mg/L......  Digestion \4\, followed by
                                     any of the following:
                                    AA direct aspiration......  .....................  3111 D-2011 or 3111 E- D3645-15 (A)........  I-3095-85.\2\
                                                                                2011.
                                    AA furnace................  .....................  3113 B-2010..........  D3645-15 (B)........
                                    STGFAA....................  200.9, Rev. 2.2
                                                                 (1994).
                                    ICP/AES...................  200.5, Rev 4.2 (2003)  3120 B-2011..........  D1976-12............  I-4471-97.\50\
                                                                 \68\; 200.7, Rev.
                                                                 4.4 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14 \3\, I-4472-
                                                                 (1994).                                                             97.\81\
                                    DCP.......................  .....................  .....................  D4190-15............  See footnote.\34\
                                    Colorimetric (aluminon)...  .....................  See footnote \61\....
9. Biochemical oxygen demand        Dissolved Oxygen Depletion  .....................  5210 B-2016..........  ....................  973.44 \3\, p. 17
 (BOD5), mg/L.                                                                                \9\, I-1578-78 \8\,
                                                                                See footnote.\10,
                                                                                63\
10. Boron--Total,\37\ mg/L........  Colorimetric (curcumin)...  .....................  4500-B B-2011........  ....................  I-3112-85.\2\
                                    ICP/AES...................  200.5, Rev 4.2 (2003)  3120 B-2011..........  D1976-12............  I-4471-97.\50\
                                                                 \68\; 200.7, Rev.
                                                                 4.4 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14.\3\
                                                                 (1994).
                                    DCP.......................  .....................  .....................  D4190-15............  See footnote.\34\
11. Bromide, mg/L.................  Electrode.................  .....................  .....................  D1246-16............  I-1125-85.\2\
                                    Ion Chromatography........  300.0, Rev 2.1 (1993)  4110 B-2011, C-2011,   D4327-17............  993.30 \3\, I-2057-
                                                                 and 300.1, Rev 1.0     D-2011.                                      85.\79\
                                                                 (1997).
                                    CIE/UV....................  .....................  4140 B-2011..........  D6508-15............  D6508, Rev. 2.\54\
12. Cadmium--Total,\4\ mg/L.......  Digestion \4\, followed by
                                     any of the following:
                                    AA direct aspiration \36\.  .....................  3111 B-2011 or 3111 C- D3557-17 (A or B)...  974.27 \3\, p. 37
                                                                                2011.                                        \9\, I-3135-85 \2\
                                                                                or I-3136-85.\2\

                                    AA furnace................  .....................  3113 B-2010..........  D3557-17 (D)........  I-4138-89.\51\
                                    STGFAA....................  200.9, Rev. 2.2
                                                                 (1994).
                                    ICP/AES \36\..............  200.5, Rev 4.2 (2003)  3120 B-2011..........  D1976-12............  I-1472-85 \2\ or I-
                                                                 \68\; 200.7, Rev.                                                   4471-97.\50\
                                                                 4.4 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14 \3\, I-4472-
                                                                 (1994).                                                             97.\81\
                                    DCP \36\..................  .....................  .....................  D4190-15............  See footnote.\34\
                                    Voltametry \11\...........  .....................  .....................  D3557-17 (C)........
                                    Colorimetric (Dithizone)..  .....................  3500-Cd-D-1990.......
13. Calcium--Total,\4\ mg/L.......  Digestion \4\, followed by
                                     any of the following:
                                    AA direct aspiration......  .....................  3111 B-2011..........  D511-14 (B).........  I-3152-85.\2\
                                    ICP/AES...................  200.5, Rev 4.2 (2003)  3120 B-2011..........  ....................  I-4471-97.\50\
                                                                 \68\; 200.7, Rev.
                                                                 4.4 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14.\3\
                                                                 (1994).
                                    DCP.......................  .....................  .....................  ....................  See footnote.\34\
                                    Titrimetric (EDTA)........  .....................  3500-Ca B-2011.......  D511-14 (A).........
                                    Ion Chromatography........  .....................  .....................  D6919-17............
14. Carbonaceous biochemical        Dissolved Oxygen Depletion  .....................  5210 B-2016..........  ....................  See footnote.\35,
 oxygen demand (CBOD5), mg/L \12\.   with nitrification                                                                              63\
                                     inhibitor.
15. Chemical oxygen demand (COD),   Titrimetric...............  410.3 (Rev. 1978)\1\.  5220 B-2011 or C-2011  D1252-06(12) (A)....  973.46 \3\, p. 17
 mg/L.                                                                                \9\, I-3560-85.\2\
                                    Spectrophotometric, manual  410.4, Rev. 2.0        5220 D-2011..........  D1252-06(12) (B)....  See footnotes \13,
                                     or automatic.               (1993).                                                             14, 83\, I-3561-
                                                                                85.\2\
16. Chloride, mg/L................  Titrimetric: (silver        .....................  4500-Cl- B-2011......  D512-12 (B).........  I-1183-85.\2\
                                     nitrate).
                                    (Mercuric nitrate)........  .....................  4500-Cl- C-2011......  D512-12 (A).........  973.51 \3\, I-1184-
                                                                                85.\2\
                                    Colorimetric: manual......  .....................  .....................  ....................  I-1187-85.\2\
                                    Automated (ferricyanide)..  .....................  4500-Cl- E-2011......  ....................  I-2187-85.\2\
                                    Potentiometric Titration..  .....................  4500-Cl- D-2011......
                                    Ion Selective Electrode...  .....................  .....................  D512-12 (C).........
                                    Ion Chromatography........  300.0, Rev 2.1 (1993)  4110 B-2011 or 4110 C- D4327-17............  993.30 \3\, I-2057-
                                                                 and 300.1, Rev 1.0     2011.                                        90.\51\
                                                                 (1997).
                                    CIE/UV....................  .....................  4140 B-2011..........  D6508-15............  D6508, Rev. 2.\54\
17. Chlorine-Total residual, mg/L.  Amperometric direct.......  .....................  4500-Cl D-2011.......  D1253-14............
                                    Amperometric direct (low    .....................  4500-Cl E-2011.......
                                     level).
                                    Iodometric direct.........  .....................  4500-Cl B-2011.......
                                    Back titration ether end-   .....................  4500-Cl C-2011.......
                                     point \15\.
                                    DPD-FAS...................  .....................  4500-Cl F-2011.......
                                    Spectrophotometric, DPD...  .....................  4500-Cl G-2011.......
                                    Electrode.................  .....................  .....................  ....................  See footnote.\16\
17A. Chlorine-Free Available, mg/L  Amperometric direct.......  .....................  4500-Cl D-2011.......  D1253-14............
                                    Amperometric direct (low    .....................  4500-Cl E-2011.......
                                     level).
                                    DPD-FAS...................  .....................  4500-Cl F-2011.......
                                    Spectrophotometric, DPD...  .....................  4500-Cl G-2011.......
18. Chromium VI dissolved, mg/L...  0.45-micron filtration
                                     followed by any of the
                                     following:
                                    AA chelation-extraction...  .....................  3111 C-2011..........  ....................  I-1232-85.\2\
                                    Ion Chromatography........  218.6, Rev. 3.3        3500-Cr C-2011.......  D5257-17............  993.23.\3\
                                                                 (1994).
                                    Colorimetric (diphenyl-     .....................  3500-Cr B-2011.......  D1687-17 (A)........  I-1230-85.\2\
                                     carbazide).
19. Chromium--Total,\4\ mg/L......  Digestion \4\, followed by
                                     any of the following:
                                    AA direct aspiration \36\.  .....................  3111 B-2011..........  D1687-17 (B)........  974.27 \3\, I-3236-
                                                                                85.\2\
                                    AA chelation-extraction...  .....................  3111 C-2011..........
                                    AA furnace................  .....................  3113 B-2010..........  D1687-17 (C)........  I-3233-93.\46\
                                    STGFAA....................  200.9, Rev. 2.2
                                                                 (1994).
                                    ICP/AES \36\..............  200.5, Rev 4.2 (2003)  3120 B-2011..........  D1976-12............
                                                                 \68\, 200.7, Rev.
                                                                 4.4 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14 \3\, I-4020-
                                                                 (1994).                                                             05 \70\ I-4472-
                                                                                97.\81\
                                    DCP \36\..................  .....................  .....................  D4190-15............  See footnote.\34\
                                    Colorimetric (diphenyl-     .....................  3500-Cr B-2011.......
                                     carbazide).
20. Cobalt--Total,\4\ mg/L........  Digestion \4\, followed by
                                     any of the following:
                                    AA direct aspiration......  .....................  3111 B-2011 or 3111 C- D3558-15 (A or B)...  p. 37 \9\, I-3239-
                                                                                2011.                                        85.\2\
                                    AA furnace................  .....................  3113 B-2010..........  D3558-15 (C)........  I-4243-89.\51\
                                    STGFAA....................  200.9, Rev. 2.2
                                                                 (1994).

                                    ICP/AES...................  200.7, Rev. 4.4        3120 B-2011..........  D1976-12............  I-4471-97.\50\
                                                                 (1994).
                                    ICP/MS....................  200.8, Rev. 5.4        3125 B-2011..........  D5673-16............  993.14 \3\, I-4020-
                                                                 (1994).                                                             05 \70\ I-4472-
                                                                                97.\81\
                                    DCP.......................  .....................  .....................  D4190-15............  See footnote.\34\
21. Color, platinum cobalt units    Colorimetric (ADMI).......  .....................  2120 F-2011 \78\.....
 or dominant wavelength, hue,
 luminance purity.
                                    Platinum cobalt visual      .....................  2120 B-2011..........  ....................  I-1250-85.\2\
                                     comparison.
                                    Spectrophotometric........  .....................  .....................  ....................  See footnote.\18\
22. Copper--Total,\4\ mg/L........  Digestion \4\, followed by
                                     any of the following:
                                    AA direct aspiration \36\.  .....................  3111 B-2011 or 3111 C- D1688-17 (A or B)...  974.27 \3\, p. 37
                                                                                2011.                                        \9\, I-3270-85 \2\
                                                                                or I-3271-85.\2\