United States
Environmental Protection
Agency
Office of Ground EPA 815-B-97-001
Water and Drinking Water March 1997
Cincinnati, OH 45268
&EPA Manual for the
f
Certification of
Laboratories Analyzing
Drinking Water
Criteria and Procedures
Quality Assurance
Fourth Edition
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EPA815-B-97-001
March 1997
MANUAL FOR THE
CERTIFICATION OF
LABORATORIES
ANALYZING
DRINKING WATER
Criteria and Procedures
Quality Assurance
Fourth Edition
Supersedes EPA/570/9-90/008, April 1990,
• EPA-814B-92-002, September 1992, and
EPA 570/9-90-008A, October 1991
US Environmental Protection Agency
Office of Water
Office of Ground Water and Drinking Water
Technical Support Center
Cincinnati, Ohio 45268
Printed on Recycled Paper
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Disclaimer
This manual has been reviewed and approved for publication by the Office of Ground Water and Drinking Water, the
Office of Research and Development and the 10 EPA Regional Offices. The mention of commercial products does
not constitute endorsement by the U.S. Environmental Protection Agency.
This manual applies specifically to activities conducted by the U.S. EPA. States that adopt this manual must make
appropriate changes so the language applies accurately to their State certification programs.
Regulatory changes made subsequently to the publication of this manual take precedence over this manual.
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Acknowledgments
This edition of the manual was prepared through the efforts of many individuals, including representatives from the
U.S. Environmental Protection Agency Office of Ground Water and Drinking Water (OGWDW), Office of Research
and Development (ORD) and Regional Offices and the States. It has as its foundation, previous editions of the
manual. Contributors to the previous editions of the manual are listed in EPA documents EPA/570/9-90/008, April
1990, EPA-570/9-82-002 October 1982 and EPA 600/8-78-008 May 1978. Contributors to this edition are listed
below.
Fourth Edition Manual Revision Committee:
Mary Ann Feige, OGWDW
Paul Berger, OGWDW
George Dilbeck, ORD
Edward M. Click, OGWDW
Caroline Madding, OGWDW
John D. Pfaff, ORD
Joseph Slayton, Region 3
Microbiology Subcommittee:
Paul Berger, Chairman
Robert Bordner, ORD
Terry C. Covert, ORD
Ralph E. Gentry, Region 4 :
Nancy Hall, University of Iowa
Margo Hunt, Region 2
Audrey McDaniels, ORD
Donald Reasoner, ORD
Gene Rice, ORD
Peggy Ryker, KY DEP
Lois C. Shadix, OGWDW
Jon Standridge, WI DNR
George J. Vasconcelos, Region 10
Radiochemistry Subcommittee:
George Dilbeck, ORD, Chairman
Stephen Pia, ORD
Patricia Honsa, ORD
James Mullins, ORD
Manual Reviewers:
Ann Marie Allen, MA DEP
George Avery, AR DOH
Brenda Barnett, WV DOH
Evelyn Baskin, WV DOH
Dale Bates, Region 7
Gary Bennett, Region 4
Wayne Black, St. Louis County DOH
Eric Blank, MO DOH
George Bowman, fWI LOH
Douglas Brune, Region 7
Robert Bordner, ORD
John Bourbon, Region I
Anthony Bright, OK DEQ
Joan Burkart, LA DOHH
Isa Chamberlain, Region 10
Kuenja Chung, Region 6
Art Clark, Region 1
Terry Covert, ORD
Allan Curtis, Region 8
Chris Dean, NM DOH
Rick Dreisch, Region 3
Lisa Doucet, Region 6
Charles Dyer, NH DBS
Stan Falk, AR DOH
Charles Feldmann, OGWDW
Lynelle Ford, LA DOHH
Stacy Freeburg, University of Iowa
Ralph Gentry, Region 4
Barbara Giesler, NM ED
Paul Gray, NM DOH
Peter Guresky, AR DOH
Stephanie Harris, Region 10
Terry Hollister, Region 6
Margo Hunt, Region 2
Andrea Jirka, Region 7
Charles Jones, Jr., Region 3
Gretchen Klebasko, Region 3
Mary Beth Lawhorn, IL EPA
George Lee, Brooks AFB
Mary Ann Lustfield, DE DPH
Ted Lyter, PA DEP
Nicholas Macelletii, CT DHS
Patricia Mack, Region 9
DeLois Manor, AR DOH
Jack McKenzie, KS DOH&E
William George Mills, VT DOH
Jeanne Mixon, LA DOHH
Joe Mobley, AR DOH
Leonard Mohnnann, TX DOH
Cathy Moore, AR DOH
Jean Munch, ORD
Deanna Murphy Baxam, MD DOH
Sheila Meyers, TX NRCC
Tom Ong, WV DOH
Alicia P. Ordona, VA DCLS
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Gary Ferryman, Region 8
Stephanie Pogue, TX NRCC
Robert Rieck, Region 10
Charles Ritchey, Region 6
Randall Romig, Region 6
Eileen Sanders, VA DCLS
Mary Ellen Schultz, Region 3
Lois M. Shadix, OGWDW
Aurora Shields, KS DOH&E
Dick Siscanaw, Region 1
Michael Sodano, ME DHS
Patricia Sosinski, Region 3
David Stockton, Region 6
Harold Stowe, VT DOH
Richard Strecker, KS DOH&E
Miguel R. Suarez, Region 5
Steven Sweeney, OGC ,
Carole Tulip, Region 3
George J. Vasconcelos, Region 10
Susan Warner, Region 3
Ted Witten, OK DEQ
Rukuson Yoh, PA DEP
IV
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Preface
Since 1978, the U. S. Environmental Protection Agency (EPA) has implemented a certification program for laboratories
performing drinking water analyses for compliance with regulations issued pursuant to the Safe Drinking Water Act.
These laboratories include EPA Regional laboratories, certain Federal laboratories, laboratories on Indian lands, principal
State laboratories in primacy States, and drinking water laboratories in non-primacy States. The elements described in
this manual are required for EPA programs. Only those elements which are in the drinking water regulations are
mandatory for the States. However, in order to provide consistency in how the program is implemented across the
country, the States are encouraged to comply with all requirements in this manual.
This document is the fourth edition of the manual, describing the program's implementation procedures and technical
criteria. It supersedes the Manual for th* f>.rtifip.atinn of laboratories Analysing Drinkinp Water. EPA-570/9-90-008
(April 1990) and Changes 1 (October 1991) and 2 (September 1992). The effective date of this manual is six months from
the date of publication.
This revision was necessary to: 1) address the reorganization in the EPA Offices; 2) provide more consistency in the way
the program is implemented; 3) address the increased complexity of the revised drinking water regulations; 4) clarify
Regional responsibilities concerning State laboratory certification programs; 5) describe the length of time a laboratory
can be "provisionally certified"; 6) define "interim" certification; and 7) improve feedback to EPA on how laboratories
perform on a routine basis. This edition resulted from an ongoing review of the laboratory certification program. Its goal
is to improve implementation of the SDWA in light of newly approved methodology and additional experience with the
program.
This document was prepared by a committee chaired by the EPA's Office of Ground Water and Drinking Water
(OGWDW) with participation of the National Exposure Research Laboratories in Cincinnati (NERL-Ci) and Las Vegas
(NERL-LV) and representatives from the ten U.S. EPA Regions and from the States.
Like previous editions, this edition is in loose-leaf format which will allow the EPA to update it more easily. Holders
of this manual should check with the EPA Region or the State Certification Officers to make sure their manual is current.
Additional copies of this manual may be obtained from the U.S. EPA, OGWDW, 26 W M.L. King Dr., Cincinnati, OH,
45268, fax number 513.569.7191. Copies may also be obtained by calling the Safe Drinking Water Hotline at
800.426.4791. The manual is posted on the Internet at www.epa.gov/OGWDW/pubs.html.
To ensure uniformity in the application of the certification program in all the Regions, internal policy requires EPA to
use the certification criteria in this manual for evaluating all public, commercial and State drinking water laboratories that
it certifies For the purposes of this document, public laboratories include county, municipal, utility, and Federal. The
Agency must also use this manual to determine the adequacy of State certification programs for drinking water
laboratories. States are encouraged to use the criteria in this manual to evaluate all laboratories that they certify.
This manual uses the terms "shall" and "must" interchangeably to refer to elements that are required by the National
Primary Drinking Water Regulations or the approved drinking water methods. These terms are also used for items
required by EPA policy or which have universal agreement. The term "should" refers to items that EPA highly
recommends.
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Table of Contents
Page
CHAPTER I: INTRODUCTION l-l
CHAPTER H: RESPONSIBILITIES EU
CHAPTER HI: IMPLEMENTATION HI-1
Evaluation of Certification Programs IE-1
Requirements for Certification of Laboratories TTT-1
Individuals) Responsible for the Certification Program III-l
On-Site Laboratory Audit Team ffl-2
Plans for Certification of Laboratories III-2
Principal State Laboratories . III-2
Certification Process m-2
Types of Certification m-3
Primacy m-3
Drinking Water Laboratories IH-4
Other Considerations for Laboratory Certification IQ-4
Laboratory Quality Assurance Plan III-4
Performance on Routine Water Samples ffl-6
Chain of Custody ffl-6
Requirements for Maintaining Certification Status . 1II-6
Criteria and Procedures for Downgrading/Revoking Certification Status m-7
Reciprocity III-9
Training HI-9
Alternate Analytical Techniques III-9
CHAPTER IV: CHEMISTRY IV-1
Personnel IV-1
Laboratory Facilities IV-1
Laboratory Equipment and Instrumentation IV-2
General Laboratory Practices " IV-2
Analytical Methods IV-3
Sample Collection, Handling and Preservation IV-3
Quality Control IV-4
Records and Data Reporting IV-7
Action Response to Laboratory Results IV-9
Tables IV-10-34
Forms for On-site Evaluation of Laboratories IV-35-54
CHAPTER V: MICROBIOLOGY V-l
Personnel V-l
. Laboratory Facilities V-l
Laboratory Equipment and Supplies V-2
General Laboratory Practices V-6
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--..--.. i Page
Analytical Methods V-7
General V-7
Membrane Filter , ._.-.., ,:.-.,.-»._ .••.-.-^ ...• -;. .-. Vr8
Multiple Tube Fermentation V-9
Presence-Absence V-10 ,
Fecal Coliform Test V-ll
Chromogenic/Fluorogenic Substrates V-12
EC Medium + MUG Test Y-13 ,
Nutrient Agar + MUG Test , V-13
Heterotrophic Plate Count V-14 ,
Techniques for Enumerating Coliforms in Source Water V-15
Sample CoUection, Handling, and Preservation V-16 -....
Quality Assurance V-17
Records and Data Reporting V-17,
Action Response to Laboratory Results V-18
Forms for On-site Evaluation of Laboratories V-19-42
CHAPTER VI: RADIOCHEMISTRY VI-1
Personnel Vlrl
Laboratory Facilities , VI-1
Laboratory Equipment and Instrumentation „ , VI-2
General Laboratory Practices VI-3
Analytical Methods ,. - ; VI-3
Sample Collection, Handling, and Preservation VI-3
Quality Assurance VI-3
Records and Data Reporting VI-5
Action Response to Laboratory Results : VI-6
Tables VI-7-21
APPENDICES .
Appendix A: Chain of Custody . , A-l
Appendix B: Protocol for On-Site Evaluations B-l
Appendix C: Definitions and Abbreviations , C-l
AppendixD: Third Party Auditors , . . D-l,..
Appendix E: Required Analytical Capability • E-l : .
Appendix F: Unregulated and Secondary Contaminants , , F-l
Appendix G: Analytical Methods for Microbiology G-l
Appendix H: Record Audits H-l
Audit Checklists . H-13-3Q
TABLES
Chemistry
Table IV-1 Glassware Cleaning IV-1.0
Table IV-2 Approved Methods for Inorganics , • IV-12 ,
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Table IV-3 Approved Methods for Organics IV-16
Table IV-4 Approved Methods for Unregulated Contaminatnts IV-19
Table IV-5 Approved Methods for Disinfectant Residuals IV-22
Table IV-6 Recommended Methods for Secondary Drinking Water Contaminants W-23
Table IV-7 Preservation and Holding Times IV 25
Table IV-8 Detection Limit Requirements » IV-29
Table IV-9 Performance Evaluation Sample Acceptance Criteria IV-31
Radiochemistry
Table VI-1 Proposed Methods for Radionuclide Analysis VI-7
Table VI-2 Sample Handling, Preservation, and Instrumentation VI-9
IX
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Chapter I
Introduction
Public water systems serving at least 25 persons or having at least 15 service connections must comply with the Safe
Drinking Water Act (SD WA) and the requirements of the National Primary Drinking Water Regulations (NPD WR) (40
CFR 141). Section 1401(1)(D) of the Act defines a National Primary Drinking Water Regulation to include "criteria and
procedures . . . [for] quality control and testing procedures to insure compliance ..." 40 CFR 142 sets implementation
requirements.
The regulations governing primacy at 40 CFR 142.10(b)(4) require a State that has primary enforcement responsibility
(primacy) to have laboratory facilities available (the Principal State Laboratory) which have been certified by EPA. In
addition, the regulations governing certification (40 CFR 141.28) require that all testing for compliance purposes be
performed by laboratories certified by the State or by EPA except that turbidity, free chlorine residual, temperature, and
pH may be performed by anyone acceptable to the State. This manual is intended to assist EPA in implementing 40 CFR
142.10(b)(4) by specifying criteria and procedures for certifying principal State laboratories. States with primacy may
also choose to use equivalent criteria and procedures similar to those in this manual for their own certification programs.
To obtain and maintain primacy, a State must comply with 40 CFR 142.10, which includes the following provisions:
The establishment and maintenance of a State program for the certification of laboratories conducting
analytical measurements of drinking water contaminants pursuant to the requirements of the State
primary drinking water regulations including the designation by the State of a laboratory officer, or
officers, certified by the Administrator, as the officials) responsible for the State's certification
program. The requirements of this paragraph may be waived by the Administrator for any State where
all analytical measurements required by the State's primary drinking water regulations are conducted
at laboratories operated by the State and certified by the Agency. (40 CFR 142.10(b)(3)(i))
Assurance of the availability to the State of laboratory facilities certified by the Administrator and
capable of performing analytical measurements of all contaminants specified in the State primary
drinking water regulations ... (40 CFR 142.10(b)(4)).
Reference to the Administrator of EPA also refers to his or her designee.
The EPA laboratory certification program extends to its Regional laboratories, laboratories on Federal Indian Lands,
principal State laboratories in primacy States, and laboratories that perform analyses under the Safe Drinking Water Act
in States without primacy. If all analyses are not performed in principal State laboratories, primacy States must have a
certification program for certifying other drinking water laboratories.
EPA's National Exposure Research Laboratory in Cincinnati, Ohio (NERL-Ci), is responsible for determining the
certification status for EPA Regional laboratories in microbiology and chemistry. The National Exposure Research
Laboratory in Las Vegas (NERL-LV) has this responsibility for radiochemistry. Regional certification officers are
responsible for the certification of the principal State laboratory in each primacy State and are also responsible for
certifying all laboratories on Federal Indian Lands and in non-primacy States. Primacy States with certification programs
are responsible for certifying the other drinking water laboratories in their State, (i.e., laboratories other than the principal
State Laboratory).
Regional laboratories must successfully analyze a set of performance evaluation samples (PEs) at least annually for all
regulated contaminants for which they wish to be certified and pass an on-site evaluation at least every three years. At
least annually, Principal State laboratories must successfully analyze a complete set of unknown performance evaluation
(PE) samples from a source acceptable to the Region for the contaminants included in the regulations which the State has
adopted, and-pass an on-site evaluation every three years. For radiochemistry certification, satisfactory performance on
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additional PEs may also be required. EPA policy requires the use of the criteria in this manual for the on-site audits of
the Regional and principal State laboratories.
Chapter II describes the responsibilities of each of the parties involved in the certification program. Chapter HI describes
how the program operates. Chapters IV, V and VI cover the technical criteria to be used during the on-site evaluation
of a laboratory for chemistry, microbiology, and radiochemistry, respectively. Optional audit forms are also included
in Chapters IV, V and VI. The appendices include the following: a recommended protocol and format for conducting
on-site laboratory evaluations, which may be used by the laboratory auditors; frequently used abbreviations and
definitions; EPA's policy on third-party auditors; a list of contaminants a principal State laboratory must have the
capability to analyze; a list of contaminants in proposed rules; a list of unregulated chemicals for which systems must
monitor under §1445 of the Safe Drinking Water Act; optional record keeping and data audit procedures; and
recommended chain-of-custody procedures to be used if necessary.
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Chapter n
Responsibilities
The success of the laboratory certification program depends upon cooperation among the organizations responsible for
its implementation. Within the Agency, responsibilities for laboratory certification are shared by the Office of Ground
Water and Drinking Water (OGWDW), the Office of Research and Development (ORD), and the Regional Offices.
Office of Ground Water and Drinking Water (OGWDW) and Office of Research and
Development (ORD)
OGWDW and ORD share the responsibility for developing and implementing the national certification program for
laboratories that analyze drinking water samples and for implementing the Safe Drinking Water Act. These responsibilities
include the following:
• Propose and promulgate regulations;
. • Assess national laboratory capacity and capability;
• Review the EPA Regional certification programs annually and evaluate the resources and personnel available
in each EPA Region to carry out the certification program;
• Develop guidance arid respond to questions and comments;
• Develop technical and administrative certification criteria to support fixture regulations;
• Assess the capacity and capability of the EPA Regional laboratories;
• Revise this manual when necessary;
• Conduct triennial on-site audits of each Regional laboratory for chemistry and microbiology and principal State
laboratories for radiochemistry (if requested by the Region);
• Prepare and distribute performance evaluation (PE) samples (Water Supply Studies) for regulated chemical,
microbiological and radiological contaminants semiannually and evaluate and distribute the results of these
studies;
• Develop and participate in training courses to support the certification program;
• Provide technical assistance to EPA and the States;
• Develop and evaluate methods for the analysis of drinking water contaminants.
NERL-LV is the lead organization for managing the certification program for laboratories performing radiochemical
analyses. At the request of a Region, NERL-LV is responsible for conducting triennial on-site audits of principal State
laboratory systems for radiochemistry. In these cases, NERL-LV must report the results of its on-site audits to the
responsible Regional certification authority, who lias the final authority to determine certification status.
EPA Regions
The Regions oversee the certification programs in the States. The Regions' responsibilities are:
• Determine the certification status for the principal State laboratory system in each primacy State;
• Coordinate NERL water supply performance evaluation studies with laboratories in the Region (some Regions
have delegated this responsibility to the States);
• Perform an annual review of State certification programs and performance evaluation results and monitor the
adequacy of State programs for certifying laboratories, as described in Chapter HI;
• Provide technical assistance to the States' EPA-eertified drinking water laboratories, as needed;
• Manage the certification program for drinking water laboratories in non-primacy States and on Federal Indian
lands using the criteria in this manual.
This last duty may be performed by the State, but the Region must retain responsibility for the on-site evaluation of the
designated principal State laboratory. Drinking water laboratories may be evaluated by the Region, or under a Region-
approved program carried out by a designated State program, hi either case, this manual must be the basis for the on-site
audits, conducted by EPA, of principal State laboratories, laboratories on Federal Indian lands, and drinking water
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laboratories in non-primacy States.
The Regional laboratory should maintain certification for as many regulated contaminants as its resources permit. It
enhances both EPA's technical assistance capabilities and credibility with those it certifies. It also ensures the laboratory
capability to analyze samples for possible enforcement actions and for States which do not have primacy. Reciprocal
agreements with other regions to share scarce resources may be needed.
Primacy States
Primacy States are required to establish and maintain a State program for the certification of laboratories conducting
analyses of drinking water compliance samples, unless all compliance samples are analyzed in the State laboratory.
The States must designate a certification officer or officers, certified by the EPA administrator or his or her designee as
the person responsible for the certification program.
States are responsible for the certification of the public and private laboratories in their State. This includes auditing the
laboratories and reviewing the PE data. States should also provide technical assistance to laboratories. They may also
choose to certify laboratories outside their State either by an on-site evaluation or reciprocity.
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Chapter III
Implementation
Evaluation of Certification Programs
The Regions and OGWDW should monitor the certification programs under their purview annually. The adequacy of
programs for certifying laboratories is evaluated by assessing each program's scope, staffing, resources, policy,
procedures, and effectiveness. This should be done in person during an on-site audit when possible and at least by means
of a questionnaire in the other years. The adequacy of these essential program elements is evaluated by:
• Reviewing the program's plan , responsibilities, organizational structure, staff (including educational background
and experience), scope and description of the certification process, downgrading criteria and processes, and use
of PE samples;
• Requesting an annual program report that includes program highlights, training, continuing education efforts,
number of on-site evaluations performed, listing of laboratories certified by discipline or contaminant, and any
certification downgrading or upgrading actions along with reasons for those actions;
« Observing on-site audits of drinking water laboratories to allow EPA Regional certification officers to evaluate
specific elements of the State certification program;
• Encouraging State and Regional laboratory auditors to observe on-site audits of their own and other laboratories
as on-the-job training;
• Sponsoring annual meetings of certification officers to discuss program issues, policies, and problems. Key
Regional, NERL, and OGWDW and State personnel should be invited to participate.
Requirements for Certification of Laboratories
In order to be eligible to analyze compliance samples under the Safe Drinking Water Act, Regional and Principal State
laboratories should meet the minimum criteria specified in this manual, should pass an on-site audit at least once every
three years, and for chemistry must satisfactorily analyze a set of PE samples or other unknown test samples annually.
EPA policy also requires that microbiology and radiochemistry laboratories also successfully analyze PE samples. For
those laboratories certified for radiochemistry, satisfactory performance on additional PE samples may also be necessary.
Individual(s) Responsible for the Certification Program
NERL (Ci) and NERL (LV) are responsible for certifying the regional laboratories, the Regions are responsible for
certifying their state laboratories, and the States are responsible for certifying private laboratories.
The certification program personnel in each Region should consist of the certification authority(s) (CA), the certification
program manager(s), and a certification team comprised of certification officers (CO) and technical experts. Additional
third party auditors and experts may be used. However, third parties must have no authority for certification decisions.
Third party auditing is discussed in Appendix D.
The Certification Authority (CA) is the person who has signature authority for all certification decisions. This is the
Director, NERL-Ci and NERL-LV and in the Regions, it is the Regional Administrator. The CA may delegate this
authority to a lower level.
Each EPA Regional Administrator or designee should appoint, by memo, an individual to manage the drinking water
laboratory certification activities in that Region. This person is the Certification Program Manager. This individual(s)
should be experienced in quality assurance, hold at least a bachelor's degree or have equivalent experience in either
microbiology, chemistry, radiochemistry or a related field and have sufficient administrative and technical stature to be
considered a peer of the directors of the laboratories being audited. It is the responsibility of the certification program
manager to assure that the Regional certification program meets the requirements of this manual.
40 CFR 142.10(b)(3)(i) requires Primacy States to designate a person certified by the Administrator as the official
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responsible for the State's certification program. This person would be the State certification authority.
On-Site Laboratory Audit Team
The certification program manager should establish one or more teams of certification officers and auditors to audit
laboratories. It is the responsibility of these teams to perform the on-site laboratory audits, review the laboratory PE data
and make recommendations to the CA concerning the certification status of the laboratories.
Team members should be experienced professionals, hold at least a bachelor's degree or equivalent education/experience
in the discipline (chemistry, radiochemistry, microbiology or a related field) for which they certify, and have recent
laboratory experience.
Team members should also have experience in laboratory evaluation and quality assurance, be familiar with the drinking
water regulations and data reduction and reporting techniques, be technically conversant with the analytical techniques
being evaluated and be able to communicate effectively, both orally and in writing.
The on-site team should include at least one CO knowledgeable in each area being audited (e.g., inorganic and organic
chemistry, radiochemistry and microbiology). EPA policy requires COs to successfully complete the appropriate EPA
laboratory certification course.
State certification programs may employ third party auditors who have passed the EPA certification officers' training
course (see Appendix D) and meet all the qualifications listed above. Although these third parties may be used to assist
the State certification officers, they may not make final certification decisions. These decisions rest with the State.
In areas where experience does not exist within the certification team (e.g., asbestos), outside expert assistance may be
obtained in the needed areas to assist the on-site team. Outside experts who have not attended the EPA certification
officer training must be accompanied by a certification officer. When using third party experts, it is critical to avoid
conflicts of interest. A third party auditor who in any way stands to benefit by the certification status of the laboratory
audited may not be used.
Plans for Certification of Laboratories
The certification authority should develop plans for certifying drinking water laboratories under her/his authority. Written
plans should include the following:
• Documentation of certification authority and certification officers and their education/experience;
• Schedules of laboratories to be audited;
• Specific types of analyses to be examined;
• Protocol to be followed;
• Strategy for assessing laboratory performance (e.g., PEs, data audits, etc.);
• Plans for providing technical assistance to laboratories which need upgrading.
Principal State Laboratories
To receive and retain primacy, the State must have the availability of laboratory facilities certified by the EPA and capable
of performing analytical measurements for all the contaminants specified in the State Primary Drinking Water Regulations.
This laboratory or laboratories are considered the Principal State Laboratory and are certified by the Region either directly
or through a reciprocal agreement.
Certification Process
The certification process begins when the laboratory director makes a formal request to the certification authority to be
certified. This application may be one of the following:
• A request for first-time certification for microbiology, chemistry, or radiochemistry;
• A request for certification to analyze additional or newly regulated contaminants;
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• A request to reapply for certification after correction of deficiencies which resulted in the
downgrading/revocation of certification status.
The response to a formal application for any of the above requests should be given within 30 days. At this time a
mutually agreeable date and time should be set for the on-site laboratory audit. The recommended protocol for conducting
these audits is given in Appendix B. If this is not a first-time certification, an on-site visit may not be necessary.
Drinking water laboratories should verify that they plan to analyze drinking water samples when they request certification.
If a laboratory has not been analyzing drinking water samples and does not plan to, the Region or State may choose not
to renew their certification. . -
Types of Certification
After review of PE sample results and an on-site visit, the certification authority should provide a written report within
45 days and classify the laboratory for each contaminant or group of contaminants according to the following rating
scheme:
• Certified - a laboratory that meets the minimum requirements of this manual and all applicable regulatory
requirements. "Certified" status may not be granted to any laboratory that has not met performance criteria specified
in the National Primary Drinking Water Regulations (NPDWR) and within the policy required by their certification
authority.
• Provisionally Certified - a laboratory that has deficiencies but demonstrates its ability to consistently produce valid
data within the acceptance limits specified in the NPDWR, and within the policy required by their certification
authority. A provisionally certified laboratory may analyze drinking water samples for compliance purposes.
Provisional certification may not be given if the evaluation team believes that the laboratory cannot perform an
analysis within the acceptance limits specified in the regulations.
• Not Certified - a laboratory that possesses major deficiencies and, in the opinion of the Certification Authority,
cannot consistently produce valid data within the acceptance limits specified in the NPDWR and within the policy
described by their certification authority.
Interim Certification - interim certification may be granted in certain circumstances when it is impossible or unnecessary
to perform an on-site audit. Interim certification status may be granted only when the CA judges that the laboratory has
the appropriate instrumentation, is using the approved methods, has adequately trained personnel to perform the analyses,
and has satisfactorily analyzed PE samples, if available, for the contaminants in question. PE samples from a commercial
vendor may be used. The CO should perform an on-site audit as soon as possible but in no case later than three years.
An example of-a situation where this type of certification is warranted might be, a laboratory that has requested
certification for the analysis of additional analytes that involves use of a method for which it already has certification or
a very similar method. The CO should review the laboratory's quality control data before granting this type of
certification.
Primacy
Primacy States in which all drinking water compliance analyses are not conducted at State operated laboratories, are
required to establish a certification program for drinking water laboratories [see 40 CFR 142.10(b)(3)(i)]. All States,
however, are encouraged to develop such programs. EPA encourages the States to base certification of drinking water
laboratories either upon criteria contained in this manual or upon statendeveloped equivalents that are at least as stringent
as this manual. All state certification programs must require compliance with all provisions of the National Primary
Drinking Water-Regulations. Those states required by regulation to develop a certification program must designate "a
laboratory officer or officers, certified by the [Regional] Administrator [or his or her designee], as the officials)
responsible for the State's certification program." (40 CFR §142.10(3)(i».
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Drinking Water Laboratories
Any laboratory which analyzes drinking water compliance samples is considered a drinking water laboratory for the
purpose of certification. This includes Federal laboratories that analyze compliance samples and other laboratories that
analyze compliance samples for Federal facilities. AH such laboratories must be certified by the State or EPA. If
requested by the State, a Region may certify Federal laboratories in its Region.
The Region should certify individual laboratories on Federal Indian lands, if requested by the tribal chairperson. These
laboratories must meet the same criteria for certification as specified in the NPDWR and this manual.
The criteria, procedures, and mechanism EPA uses to certify municipal or private drinking water laboratories are the
same as those for principal state laboratories.
Other Considerations for Laboratory Certification
Laboratory Personnel
The laboratory should have sufficient supervisory and other personnel, with the necessary education, training, technical
knowledge and experience for their assigned functions.
Laboratory Director/Manager or Technical Director
The laboratory director/manager should be a qualified professional with the technical education and experience and
managerial capability commensurate with the size/type of the laboratory. The laboratory director/manager is ultimately
responsible for ensuring that all laboratory personnel have demonstrated proficiency for their assigned functions and that
all data reported by the laboratory meet the required quality assurance (QA) criteria and regulatory requirements.
Quality Assurance Officer/Manager
The QA officer/manager should be independent from the laboratory management if possible and have direct access to the
highest level of management. The QA officer/manager should have a bachelor's degree in science, training in quality
assurance principles commensurate with the size and sophistication of the laboratory and at least one year of experience
in quality assurance/control. The QA officer/manager should have at least a working knowledge of the statistics involved
in quality control of laboratory analysis and a basic understanding of the methods which the laboratory employs.
Laboratory Quality Assurance Plan
All laboratories analyzing drinking water compliance samples must adhere to the QC procedures specified in the methods.
This is to ensure that routinely generated analytical data are scientifically valid and defensible and are of known and
acceptable precision and accuracy. To accomplish these goals, each laboratory should prepare a written description of
its QA activities (a QA plan). It is the responsibility of the QA manager to keep the QA plan up to date. All laboratory
personnel must be familiar with the contents of the QA plan. This plan should be submitted to the auditors for review
prior to the on-site visit or should be reviewed as part of the on-site visit.
The laboratory QA plan should be a separately prepared text. However, documentation for many of the listed QA plan
items may be made by reference to appropriate sections of this manual, the laboratory's standard operating procedures,
(SOPs) or other literature (e.g., promulgated methods, Standard Methods for the Examination of Water and Wastewater,
etc.). The QA Plan should be updated as necessary.
At a minimum, the following items should be addressed in each QA plan:
1. Laboratory organization and responsibility
• include a chart or table showing the laboratory organization and lines of responsibility, including QA managers;
• list the key individuals who are responsible for ensuring the production of valid measurements and the routine
assessment of measurement systems for precision and accuracy (e.g., who is responsible for internal audits and
reviews of the implementation of the plan and its requirements);
• reference the job descriptions of the personnel and describe training to keep personnel updated on regulations
and methodology, and document that laboratory personnel have demonstrated proficiency for the methods they
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perform.
2. Process used to identify clients' Data Quality Objectives
3. SOPs with dates of last revision
• keep a list of SOPs
• ensure that current copies of SOPs are in the laboratory and in the QA Managers files;
• ensure that SOPs are reviewed annually and revised as changes are made;
• ensure that SOPs have signature pages and revisions dated.
4. Field sampling procedures
• describe the process used to identify sample collectors, sampling procedures and locations, required
preservation, proper containers, correct sample container cleaning procedures, sample holding times from
collection to analysis, and sample shipping and storage conditions;
• ensure that appropriate forms are legibly filled out in indelible ink or hard copies of electronic data are available.
See Chapters IV, V, and VI for specific items to be included;
• describe how samples are checked when they arrive for proper containers and temperature and how samples are
checked for proper preservation (e.g., pH, chlorine residual) before analysis;
• ensure that sampling protocol is written and available to samplers.
5. Laboratory sample handling procedures
• use bound laboratory note books, filled out in ink; entries dated and signed (A secure, password protected,
electronic data base is acceptable);
• store unprocessed and processed samples at the proper temperature, isolated from laboratory contaminants,
standards and highly contaminated samples and, sometimes, each other; holding times may not be exceeded;
• maintain integrity of all samples, (e.g., by tracking samples from receipt by laboratory through analysis to
disposal);
• require Chain-of-Custody procedures for samples likely to be the basis for an enforcement action (see Appendix
A); ,
• specify criteria for rejection of samples which do not meet shipping, holding time and/or preservation
requirements and procedures for notification of sample originators.
6. Calibration procedures for chemistry and radiochemistry (may reference SOP) ,
• specify type of calibration used for each method and frequency of use;
• describe standards' source, age, storage, labeling;
• perform data comparability checks;
• use control charts and for radiochemistry, report counting errors with their confidence levels.
7. Analytical procedures (may reference SOP)
• cite complete method manual;
• describe quality control procedures required by the methods that must be followed.
8. Data reduction, validation, reporting and verification (may reference SOP)
• describe data reduction process: method of conversion of raw data to mg/L, picocuries/L, coliforms/100 mL,
etc.;
• describe data validation process;
• describe reporting procedures, include procedures and format;
• describe data verification process;
• for radiochemistry, describe reporting of counting uncertainties and confidence levels;
• describe procedure for data corrections.
9. Type of quality control (QC) checks and the frequency of their use (see Chapters IV, V and VI).(may reference SOP)
Parameters for chemistry and radiochemistry should include or reference:
• instrument performance check standards;
• frequency and acceptability of method detection limit (MDL) calculations;
• calibration, internal and surrogate standards;
• laboratory reagent blank, field reagent blank and trip blank;
• field and laboratory matrix replicates;
• quality control and performance evaluation samples;
• laboratory fortified blank and laboratory fortified sample matrix replicates;
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• initial demonstration of method capability and use of control charts;
• qualitative identification/confirmation of contaminants.
Parameters for microbiology should include or reference:
• positive and negative culture controls;
• confirmation/verification of presumptive total colifonn positive samples;
• sterility controls;
• performance evaluation and quality control samples.
10. List schedules of internal and external system and data quality audits and inter laboratory comparisons (may reference
SOP)
11. Preventive maintenance procedures and schedules
• describe location of instrument manuals and schedules and documentation of routine equipment maintenance;
• describe availability of instrument spare parts in the laboratory;
• list any maintenance contracts in place.
12. Corrective action contingencies
• describe response to obtaining unacceptable results from analysis of PE samples and from internal QC checks;
• name persons responsible for the various corrective actions;
• describe how corrective actions taken are documented;
13. Record keeping procedures
• describe procedures and documentation of those procedures;
• list length of storage, media type (electronic or hard copy);
• describe security policy of electronic databases.
If a particular item is not relevant, the QA plan should state this and provide a brief explanation. A laboratory QA plan
should be responsive to the above items while remaining brief and easy to follow. Minimizing paperwork, while
improving dependability and quality of data, are the intended goals.
Performance on Routine Water Samples
Each certification authority should develop a strategy to assess laboratory performance on routine water samples as part
of its certification program. This strategy may include one or more of the following approaches or some other approach:
blind audit samples; analysis of an unknown sample during the on-site evaluation; a split sample program with the
laboratory; a data audit; or observation of daily routine during an on-site visit. Each Certification Authority should
develop a written plan that addresses this issue. The Regional plan is approved by OGWDW with NERL concurrence.
The State plan is approved by the Region.
Chain-of-Custody Procedures
Certified laboratories, when requested to process a sample for possible legal action against a supplier, should use an
adequate chain-of-custody procedure. An example of such a procedure is found in Appendix A. The State or Region
should seek input from its attorney general's office to ensure that the laboratory's procedures are adequate. The
procedure used should be documented.
Requirements for Maintaining Certification Status
Performance Evaluation (PE) Samples
All certified drinking water laboratories must satisfactorily analyze PE samples or other unknown test samples to maintain
certification for inorganic and organic contaminants. Currently, the regulations stipulate that if a laboratory satisfactorily
analyzes 80% of the regulated Volatile Organic Chemicals, it may be certified for all of them (except vinyl chloride which
is certified separately). If the VOCs are provided in more than one vial, they must be considered collectively. However,
it is recommended that a laboratory not be certified for a particular VOC which is unsatisfactorily analyzed two times
in succession.
If the laboratory does not analyze the PE sample, or other unknown test sample, within the acceptance limits specified
in the regulations, or within policy described by their certifying authority, the certifying authority must follow the
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procedure discussed in the section entitled, "Criteria and Procedures for Downgrading/Revoking Certification Status."
If a laboratory wishes to be certified for a contaminant by more than one method, it should analyze the PE samples by
each method for which it wishes to be certified. If the PE provider cannot accommodate PE data by more than one
method, the additional data should be submitted directly to the certification officer. The methods listed on the laboratory's
certification certificate must be the methods by which the PE samples were analyzed.
The laboratory should be able to provide documentation to the certification authority that the person(s) analyzing any PE
sample is a laboratory employee who routinely analyzes drinking water compliance samples.
To maintain certification in radiochemistry, NERL-LV requires laboratories to participate satisfactorily in the NERL-LV
PE program. •
Methodology
Laboratories must use the methods specified in the drinking water regulations at 40 CFR part 141 These methods are
listed in Chapters IV, V, VI, and Appendix G.
Notification of Certifying Authority (CA) of Major Changes
Certified laboratories should notify the appropriate CA (Regional Administrator or designee or the appropriate NERL)
in writing, within 30 days of major changes in personnel, equipment, or laboratory location. A major change in
personnel is defined as the loss or replacement of the laboratory supervisor or a situation in which a trained and
experienced analyst is no longer available to analyze a particular parameter for which certification has been granted. The
CA should discuss the situation with the laboratory supervisor and establish a schedule for the laboratory to address major
changes. If the CA determines that the laboratory can no longer produce valid data, the CA should follow the procedure
for revocation of certification.
On-Stte Evaluation
The CA should be satisfied that a laboratory is maintaining the required standard of quality for certification. Normally,
this should be based on a recommendation from an on-site evaluation. If the laboratory undergoes a major change,
however, or if it fails a PE sample or other unknown test sample, the C A should consider conducting an evaluation before
the usual three year period has expired.
Criteria and Procedures for Downgrading/Revoking Certification Status
Criteria for Downgrading Certification Status
A laboratory should be downgraded to "provisionally certified" status for a contaminant or group of contaminants for any
of the following reasons:
• Failure to analyze a PE sample at least annually within the acceptance limits specified in the regulations, or, if
there are no requirements specified in the regulations, within policy described by their certifying authority;
• Failure of a certified laboratory to notify the CA within 30 days of major changes (e.g., in personnel, equipment,
or laboratory location);
« Failure to satisfy the CA that the laboratory is maintaining the required standard of quality, based upon an EPA
on-site evaluation;
• Failure to report compliance data to the public water system or the State drinking water program in a timely
manner, thereby preventing compliance with Federal or State regulations and endangering public health. Data
which may cause the system to exceed an MCL should be reported as soon as possible.
Procedures for Downgrading to "Provisionally Certified" Status
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If a laboratory is subject to downgrading on the basis of the above indicated criteria, the CA should notify the laboratory
director or owner of its intent to downgrade (by registered or certified mail) within 14 days from becoming aware of the
situation warranting downgrading. The laboratory director should review the problems cited and, within 30 days of
receipt of the letter, send a letter to the CA specifying what immediate corrective actions are being taken and any
proposed actions that need the concurrence of the CA. The CA should consider the adequacy of the response and notify
the laboratory in writing (by registered or certified mail) of its certification status within 14 days of receipt of its response.
The CA should follow up to ensure that corrective actions have been taken.
If a laboratory fails to analyze a PE or other unknown sample within the acceptance limits, the C A should not downgrade
certification if the laboratory identifies and corrects the problem to the CA's satisfaction within 30 days of being notified
of the failure. If, after a review of the submitted information, the CA determines that the laboratory need not be
downgraded, then within 30 days of this decision, the CA should send the laboratory another unknown sample containing
the failed contaminant. If the laboratory analyzes this second unknown sample within the acceptance limits established
by the EPA or State (using the most recent PE summary statistical compilations), the laboratory should not be
downgraded. If the laboratory fails to analyze this second unknown sample within the established limits, the CA should
downgrade the laboratory to "provisionally certified" status and notify the laboratory within 14 days (by registered or
certified mail). Laboratories should be downgraded only for the analyte failed, except where EPA/State certifies a group
of related analytes based on a limited number of analytes in the group. (See "Periodic Performance Evaluation Samples''
for additional information.) _
During any phase of this procedure, a laboratory may request that the EPA or State provide technical assistance to help
identify and resolve any problem.
Once the CA notifies a laboratory, in writing, that it has been downgraded to' "provisionally certified" status for
procedural, administrative, equipment or personnel deficiency, the laboratory should correct its problem within three
months (six months for major equipment replacement). If the laboratory was downgraded to "provisionally certified"
status because of a failure to analyze a PE sample (or other unknown test sample) within the acceptance limits specified
in the regulations, or within policy required by their certifying authority, the laboratory should correct its problems and
satisfactorily analyze another PE sample (or other unknown sample) within one month of receipt of the second PE sample.
A provisionally certified laboratory may continue to analyze samples for compliance purposes, but should notify its clients
of its downgraded status and provide that information, in writing, on any report.
Criteria for Revoking Certification Status
A laboratory shall be downgraded from certified, provisionally certified or interim certified status to "not certified" for
a particular contaminant analysis for the following reasons:
• Submission of a PE sample to another laboratory for analysis and reporting the data as its own;
• Falsification of data or other deceptive practices;
• Failure to use the analytical methodology specified in the regulations;
• For provisionally certified laboratories, failure to successfully analyze a PE sample or any other unknown test
sample for a particular contaminant'within the acceptance limits specified;
• For provisionally certified laboratories, failure to satisfy the CA that the laboratory has corrected deviations
identified during the on-site evaluations;
• For provisionally certified laboratories, persistent failure to report compliance data to the public water system
or the State drinking water program in a timely manner thereby preventing compliance with Federal and/or State
regulations and endangering public health. Data which may cause the system to exceed an MCL should be
reported as soon as possible.
Procedures for Revocation
The CA should notify the laboratory, in writing (by registered or certified mail) of the intent to revoke certification. If
the laboratory wishes to challenge this decision, a notice of appeal should be submitted in writing to the C A within 30
days of receipt of the notice of intent to revoke certification. If no notice of appeal is filed, certification shall be revoked.
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The notice of appeal should be supported with an explanation of the reasons for the challenge and must be signed by a
responsible official from the laboratory such as the president/owner for a commercial laboratory, or the laboratory
supervisor in the case of a municipal laboratory or the laboratory director for a State or Regional laboratory. «
Within 30 days of receipt of the appeal, the CA should make a decision and notify the laboratory in writing (by registered
or certified mail). Denial of the appeal shall result in immediate revocation of the laboratory's certification. Once
certification is revoked, a laboratory may not analyze drinking water samples for compliance until its certification has been
reinstated.
If the appeal is determined to be valid, the CA should take appropriate measures to reevaluate the facility and notify the
laboratory, in writing (by registered or certified mail), of its decision within 30 days of the reevaluation.
Reinstatement of Certification
Through a written request, a laboratory may seek reinstatement of certification, 'when and if the laboratory can
demonstrate to the CA's satisfaction that the deficiencies which produced provisionally certified status or revocation have
been corrected. This may include an on-site evaluation, successful analysis of unknown samples or any other measure
the CA deems appropriate. ' '
Reciprocity
Reciprocity, mutually acceptable certification among Regions and/or primacy States, is strongly endorsed by EPA as a
highly desirable element in the certification program for drinking water laboratories. EPA also believes that use of a third
party auditing agent by more than one State could promote reciprocity. (See Appendix D)
States are encouraged to adopt provisions in their laws and regulations to permit reciprocity. Even though ultimate
responsibility for reciprocal certification resides with the Regions and primacy States, the States may ask for the assistance
of EPA in cases involving clarification of what should be considered in a reciprocal agreement. Such requests should
be submitted to the Region or OGWDW through the Region.
Training
Training is an integral part of the laboratory certification process for personnel conducting on-site evaluations of
laboratories on behalf of either the Regional Office or a primacy State.
EPA policy requires that all Regional certification officers must initially pass the appropriate EPA laboratory certification
training courses for the discipline for which they certify (chemistry, radiochemistry or microbiology). All laboratory
auditors should be experienced professionals and have at least a bachelor's degree or equivalent education/experience in
the discipline for which they certify and recent laboratory experience in the field for which they audit laboratories. Third
party auditors (see Appendix D) must also pass the EPA certification training course. Outside experts, retained for their
knowledge in a limited area (e.g., asbestos) are not required to pass the laboratory certification course if they are used
as part of an on-site audit team which includes a certification officer. Periodic training for both laboratory auditors and
analysts should be provided by the Regions. Certification officers should attend refresher training programs at least every
five years to keep their knowledge of the methods and the drinking water program current. It is highly recommended
that certification officers have recent bench experience in the methods for which they certify. OGWDW will notify
certification officers of major updates/changes to EPA's certification program. It is recommended that the States use these
same criteria in their certification programs.
^
Alternate Analytical Techniques
EPA approves analytical methods for all regulated drinking water contaminants. A regulation for a particular
contaminant will include approval of one or more methods that must be used to determine that contaminant. Subsequent
to publishing a rule (promulgation), the Agency may approve new methods or modifications of EPA approved methods
through another rule.
"With the written permission of the State, concurred in by the Administrator of the US EPA, an alternate analytical
technique may be employed. An alternate technique shall be accepted only if it is substantially equivalent to the
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prescribed test in both precision and accuracy as it relates to the determination of compliance with any MCL."(CFR
141.27(a)
Anyone can request that EPA approve a new method or modification of a method already approved by EPA, by submitting
EPA-specified data and other information to the Director, Analytical Methods Staff, Office of Science and Technology
(MS4303), Office of Water, USEPA, 401 M Street, SW, Washington DC 20460. EPA will evaluate the material to
determine whether the method meets EPA criteria. If a method meets the specified criteria, it will be approved. This
involves a formal proposal in the Federal Register, public comment, and finally (unless otherwise indicated by the public
comments or other new information), promulgation in the Federal Register. Once approved (i.e., promulgated), any
laboratory may use the method.
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Chapter IV
Critical Elements for Chemistry
1. Personnel
1.1 Laboratory Supervisor
The laboratory supervisor should have at least a bachelor's degree with a major in chemistry or equivalent and at least
one year of experience in the analysis of drinking water. The laboratory supervisor should have at least a working
knowledge of quality assurance principles. The laboratory supervisor has immediate responsibility to insure that all
laboratory personnel have demonstrated their ability to satisfactorily perform the analyses to which they are assigned and
that all data reported by the laboratory meet the required quality assurance and regulatory criteria.
1.2 Laboratory Analyst
The laboratory analyst should have at least a bachelor's degree with a major in chemistry or equivalent and at least one
year of experience in the analysis of drinking water. If the analyst is responsible for the operation of analytical
instrumentation, he or she should have completed specialized training offered by the manufacturer or another qualified
training facility or served a period of apprenticeship under an experienced analyst. The duration of this apprenticeship
is proportional to the sophistication of the instrument. Data produced by analysts and instrument operators while in the
process of obtaining the required training or experience are acceptable only when reviewed and validated by a fully
qualified analyst or the laboratory supervisor.
Before beginning the analysis of compliance samples, the analyst must demonstrate acceptable results for blanks,
precision, accuracy, method detection and specificity and satisfactory analysis on unknown samples.
1.3 Technician
The laboratory technician should have at least a high school diploma or equivalent, complete a method training program
under an experienced analyst and have six months bench experience in the analysis of drinking water samples.
Before beginning the analysis of compliance samples, the technician must demonstrate acceptable results for blanks,
precision, accuracy, method detection and specificity and satisfactory analysis on unknown samples.
1.4 Sampling Personnel
Personnel who collect samples should have been trained in the proper collection technique for all types of samples which
they collect. Their technique should be reviewed by experienced sampling or laboratory personnel.
1.5 Waiver of Academic Training Requirement
The certification officer may waive the need for specified academic training, on a case-by-case basis, for highly
experienced analysts.
Training records should be maintained for all personnel. These should include all job related formal training taken by
the analyst which pertains to any aspect of his/her responsibilities, including but not limited to analytical methodology,
laboratory safety, sampling, quality assurance^ data analysis, etc.
2. Laboratory Facilities
The analysis of compliance samples should be conducted in a laboratory where the security and integrity of the samples
and the data can be maintained. The laboratory facilities should be clean, have adequate temperature and humidity
control, have adequate lighting at the bench top and must meet applicable OSHA standards. The laboratory must have
provisions for the proper storage and disposal of chemical wastes. The appropriate type of exhaust hood is required
where applicable.
There should be sufficient bench space for processing samples. Workbench space should be convenient to sink, water,
gas, vacuum and electrical sources free from surges. Instruments should be properly grounded. For safety reasons,
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inorganic and organic facilities should be in separate rooms; organic analysis and sample extraction should also be
separated to prevent cross contamination. The analytical and sample storage areas should be isolated from all potential
sources of contamination. There should be sufficient: storage space for chemicals, glassware and portable equipment,
sufficient floor and bench space for stationary equipment and areas for cleaning materials.
3. Laboratory Equipment and Instrumentation
The laboratory must have the instruments and equipment needed to perform the approved methods for which certification
has been requested. The checklist on page 43 of this chapter provides more information on the necessary equipment.
All instruments should be properly maintained and calibrated.
4. General Laboratory Practices
4.1 General
4.1.1 Chemicals/reagents: Chemicals and reagents used must meet the specifications in the method. If not
specified, then "Analytical reagent grade" (AR) or American Chemical Society (ACS) grade chemicals or better
should be used for analyses in certified laboratories. Consult Standard Methods for the Elimination of Water and
Wastewater, 18th Edition, part 1070 for more detailed information on reagent grades.
4.2 Inorganic Contaminants
4.2.1 Reagent water: The laboratory should have a source of reagent water having a resistance value of at least
0.5 megohms (conductivity less than 2.0 micromhos/cm) at 25°C. High quality water meeting such specifications
may be purchased from commercial suppliers. Quality of reagent water is best maintained by sealing it from the
atmosphere. Quality checks to meet specifications above should be made and documented at planned intervals
based on use. This planned interval should not exceed one month. Individual analytical methods may specify
additional requirements for the reagent water to be used.
4.2.2 Glassware preparation: Specific requirements in the methods for the cleaning of glassware must be
followed. If no specifications are listed, then glassware should be washed in a warm detergent solution and
thoroughly rinsed first with tap water and then with reagent water. This cleaning procedure is sufficient for
general analytical needs. It is advantageous to maintain separate sets of suitably prepared glassware for the nitrate,
mercury, and lead analyses due to the potential for contamination from the laboratory environment. Refer to Table
IV-1 for a summary of glassware cleaning procedures.
4.3 Organic Contaminants
4.3.1 Reagent water: Reagent water for organic analysis must be free from interferences for the analytes being
measured. It may be necessary to treat water with activated carbon to eliminate all interferences. If individual
methods specify additional requirements for the reagent water to be used, these .must be followed.
4.3.2 Glassware preparation: Glassware cleaning requirements specified in the methods must be followed.
Table IV-1 summarizes the cleaning procedures specified in the EPA methods.
4.4 Laboratory safety
While safety criteria are not an aspect of laboratory certification, laboratory personnel should apply general and customary
safety practices as a part of good laboratory practices. Each laboratory is encouraged to have a safety plan as part of their
standard operating procedure which includes personnel safety, training and protection. Where safety practices are
included in an approved method (i.e., 515.1), they must be followed. See Standard Methods for the Examination of Water
and Wastewater, part 1090 for a discussion of laboratory safety.
4.5 Quality Assurance
Laboratories should maintain current Quality Assurance Plans as described in Chapter 3. All laboratory activities
including sampling, test methods, instrument operation, data generation and corrective action should be described in the
Plan. Plans should be available to all personnel. .
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5. Analytical Methods
5.1 General :
A list of approved methods for inorganic and organic contaminants can be found in Tables IV-2 and;F/-3, respectively.
Methods manuals should be available in-house. Allowed modification to the methods should be documented. All
procedural steps in these methods are considered requirements. Other methods cannot be used for compliance samples
unless approval has been granted by the Agency. Contact the appropriate certifying authority for an alternate test
procedure application. Application for the use of an alternate method may require acceptable comparability data. Table
IV-4 lists the methods which must be used for contaminants which are regulated for monitoring only (have no MCLs);
Table IV-5 lists the methods which must be used for the analysis of disinfectants. Recommended methods for Secondary
contaminants are listed in Table IV-6. For more information, see Appendix H, section 2.1
5.2 Analyses approved by the State
Measurements for turbidity, pH, temperature, residual disinfectant, calcium, orthophosphate, silica, alkalinity, and
conductivity need not be made in certified laboratories, but may be performed by any persons acceptable to the State.
However, approved methodology must be used (Tables IV-2-5). The State should institute a quality assurance program
to assure validity of data, from these measurements. ~
5.2.1 Turbidity standards: Sealed liquid turbidity standards purchased from the instrument manufacturer should
be calibrated against properly prepared and diluted formazin or styrene divinylbenzene polymer standards at least
every four months in order to monitor for any eventual deterioration. This calibration should be documented.
These standards should be replaced when they do not fall within 15 % of the concentration of the standard. Solid
turbidity standards composed of plastic, glass, or other materials are not reliable and should not be used.
:•..:.'- 5.2.2 Residual chlorine standards: If visual comparison devices such as color wheels or sealed ampules are
used for determining free chlorine residual, the standards incorporated into such devices should be calibrated at
least every six months. These calibrations should be documented. Directions for preparing temporary and
permanent type visual standards can be found in Method 4500-C1-G, of Standard Methods for the Examination
of Water and Wastewater, 18di Edition, 1992. By comparing standards and plotting such a comparison on graph
paper, a corrective factor can be derived and applied to future results obtained on the now calibrated apparatus.
6. Sample Collection, Handling, and Preservation
The manner in which samples are collected and handled is critical to obtaining valid data. It is important that a written
sampling protocol with specific sampling instructions be available to and used by sample collectors and available for
inspection by the certification officer. (Appendix A, Chain-of-Custody).
6.1 Rejection of Samples
The laboratory must reject any sample taken for compliance purposes which does not meet the criteria in 6.2 through 6.6
and notify the authority requesting the analyses. See Appendix H section 1.3.
6.2 Sample Containers and Preservation
The type of sample container and the required preservative for each inorganic and organic chemical contaminant are listed
in TableTV-7. The use of "blue ice" is discouraged because it generally does not maintain the temperature of the sample
at 4C or less. If blue ice is used, it should be frozen at die time of sampling, the sample should be chilled before packing,
and special notice must be taken at sample receipt to be certain the required temperature (4C) has been maintained.
6.3 Maximum Holding Times :
Samples must be analyzed within the maximum holding times listed in Table IV-7.
6.4 Sample Collection and Transport
There must be strict adherence to correct sampling procedures, complete identification of the sample, and prompt transfer
of the sample to the laboratory. When the laboratory is not responsible for sample collection and transport, it miist verify
that the paperwork, preservatives, containers and holding times are correct or reject the sample. For more information,
see Appendix H, section 1.0. ,
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appropriate concentration (e.g., a percentage of the MCL or mid point in the calibration range). Over time,
samples from all routine sample sources should be fortified as much as is practical. If any of these checks
are not within the control limits specified in 7.2.7, and the laboratory performance is in control, the result for
that sample must be labeled to inform the data user that the results are suspect due to matrix effects. See.
Appendix H, section 2.5.2.
7.2.7 Control Charts: Control charts, generated from laboratory fortified blanks (LFBs) should be
maintained by the laboratory. Until sufficient data are available from the laboratory, usually a minimum of 20
to 30 test results on a specific analysis, the laboratory should use the control limits (if specified) in the :
methods.
When sufficient data become available, the laboratory should develop FRB control charts from the mean
percent recovery (x) and the standard deviation (S) of the percent recovery for the.QC checks specified above
(see Chapter VI of the Handbook for Analytical QC in Water and Wastewater Laboratories, EPA-600/4-79-
019 or Standard Methods for the Examination of Water and Wastewater, part 1020B, or similar QC reference
texts for further information). These data are used to establish upper and lower control limits as follows:
upper control limit = ,x + 3S (upper warning limit + 2S)
lower control limit = x - 3S (lower warning limit - 2S)
After each five to ten new recovery measurements, new control limits should be calculated using the most
recent 20-30 data points. These calculated control limits should not exceed those established in the method. If
any of these control limits are tighter than the method specifications, the laboratory should use the tighter
criteria.
7.2.8 Initial Demonstration of Capability: Before beginning the analysis of compliance samples, an initial
demonstration of capability (IDC) must be performed for each method. It is recommended that an IDC be
performed for each analyst and instrument. In addition, it is recommended that the IDC also address the
variability introduced if more than one sample preparation technician is used. Precision, accuracy and MDL
should be similar for each technician. The IDC includes a demonstration of the ability to achieve a low
background, the precision and accuracy required by the method, the method detection limit (MDL) in
accordance with the procedure given in 40 CFR 136, Appendix B and satisfactory performance on an
unknown sample. This definition is more encompassing than the definition of IDC in the methods. The IDC
should be redone if there is a change in analyst, instrument or a significant change in the method. Minor
changes should prompt a check to ascertain that the precision, accuracy and sensitivity have been maintained.
7.2.9 Quantitation of Multicomponent Analytes (toxaphene, chlordane and PCBs) The quantitation of multi-
component analytes requires professional judgment on the part of the analyst. This is required due to the
complex nature of the chromatography involved, sample weathering and degradation and interferences that
may be present in the samples. The pattern of peaks found in the sample should be examined carefully and
compared to a standard. The peaks in the sample that match the peak ratios in the standard can be used in
quantitation. Peaks that have obvious interferences (such as pesticides or phthalates or peaks exhibiting poor
peak shape) or appear to have been degraded or weathered should not be used for quantitation. A
representative number (5-9) of peaks is suggested. Peak area should be used for quantitation and the analyst
should ensure that the samples and standards have been integrated in the same manner. Quantitation can be
done by using the total peak area (comparing the area of the 5-9 peaks used for quantitation of the sample to
the area of the standard) or by calculating each peak separately (using area) and taking the average
concentration of the 5-9 peaks. Because of factors such as peak shape and baseline rise, the most accurate
quantitation is obtained when the concentration of the sample closely matches that of the standard (e.g., within
20% of the standard). See EPA Method 8081, Organnchlnrine Pesticides andPCBs as Aroclors by Gas
rhroTrmtngrflphy; Capillary Column Technique, for a more detailed discussion of quantitation of
multicomponent analytes.
IV-6
-------
Note: PCBs are qualitatively identified as Aroclors and measured for compliance purposes as
decachlorobiphenyl. Chlordane is regulated as technical chlordane, a mixture of at least 11 major components
and 30 minor ones.
7.2.10 Periodic MDL Calculation: Method detection limit calculations are required by regulation for
VOCs, lead and composited samples. Table IV-8 lists the MDL requirements in the drinking water
regulations. The CFR requires that a method detection limit of 0.0005 mg/L be attained for VOCs.
For inorganics, a method detection limit of 1/5 of the MCL must be attained for compositing. Otherwise, the
MCL is the required detection limit for inorganics. For SOCs, the detection limits listed in the CFR must be
attained for compositing, but are currently not required for certification. This is somewhat contradictory,
because the detection limits listed are the required monitoring triggers. Most methods require initial MDL
calculations for all analytes. It is therefore recommended that the certification officers require the laboratories
to calculate their detection limits for all regulated contaminants until a change is made in the regulation. See
Appendix H, section 2.3 for more guidelines on MDLs.
It is recommended that sample preparation and analyses for the MDL calculation be made over a period of at
least three days to provide a more realistic MDL. The analyst should recalculate MDLs when a significant
change in the method, analyst or instrument is made which would affect the MDL. In addition, the analyst
should regularly check the MDLs by analyzing laboratory fortified blanks at the same level as those that were
used to calculate the MDL.
The calculation of MDLs by the CFR procedure may not be adequate for Aroclors, toxaphene and chlordane
because they require pattern or peak profile recognition for identification. Presently, no standard procedure
exists, so it is recommended that the MDL be defined as the lowest concentration for which pattern
recognition is possible.
7.2.11 Low Level Quantitation: The laboratory's detection limits should be reported to the client along with
the data. Many laboratories are uneasy reporting all detections above their MDLs because they realize that
statistically, contaminants present at the MDL concentration may be missed 50% of the time. Also,
contaminants may be reported which cannot be confirmed by a second technique. Laboratories may prefer not
to report contaminants at levels less than two to three times their MDL or below the level at which they
routinely analyze their lowest standard. While this may be a scientifically sound practice, whether it is an
acceptable practice will depend on State and Federal reporting requirements. It is important for users of data
to understand the statistical and qualitative significance of the data. Laboratories may be required by the
States to achieve a specific MDL or quantitation limit more stringent than that required by EPA.
7.2.12 Laboratory Fortified Blanks: The analyst should routinely verify the reporting limit (if one is used)
for each analyte by analyzing a laboratory fortified blank at the reporting level. In addition, most methods
require that a laboratory fortified blank be analyzed with each batch of samples at ten times the MDL or a mid
level standard. Precision and accuracy data must be documented for this determination.
7.2.13 Qualitative Identification: The analyst should also verify at what concentration specificity (qualitative
identification/confirmation) can be determined (e.g., a spectrum should be identifiable or second column
confirmation should be possible).
8. Records and Data Reporting
8.1 Legal Defensibility: Compliance monitoring data should be made legally defensible by keeping thorough and
accurate records. The QA plan and/or SOPs should describe the policies and procedures used by the facility for
record retention and storage. If samples are expected to become part of a legal action, chain of custody procedures
should be used ( See Appendix A).
8.2 Maintenance of Records: Public Water Systems are required to maintain records of chemical analyses of
IV-7
-------
compliance samples for 10 years (40 CFR 141.33) and lead and copper for 12 years (40 CFR 141.91). The laboratory
should maintain easily accessible records for five years or until the next certification data audit is complete,
whichever is longer. The client water system should be notified before disposing of records so they may request
copies if needed. This includes all raw data, calculations, and quality control data. These data files may be either
hard copy, microfiche or electronic. Electronic data sihould always be backed up by protected tape or disk or hard
copy. If the laboratory changes its computer hardware or software, it should make provisions for transferring old
data to the new system so that it remains retrievable within the time frames specified above. Data which is expected
to become part of a legal action will probably need to be maintained for a longer period of time. Check with your
legal counsel. See Appendix H, section 3.0, and Good Automated Laboratory Practices, EPA 2185, Office of
Information Management, Research Triangle Park, NC 27711, 8/10/95.
8.3 Sampling Records: Data should be recorded in ink with any changes lined through such that original entry is
visible. Changes should be initialed and dated. The following information should be readily available in a summary
or other record(s):
8.3.1 Date, location (including name of utility and PWSS ID #), site within the system, time of sampling,
name, organization and phone number of the sampler, and analyses required;
8.3.2 Identification of the sample as to whether it is a routine distribution system sample, check sample,
raw or finished water sample, repeat or confirmation sample or other special purpose sample;
8.3.3 Date of receipt of the sample;
8.3.4 Sample volume/weight, container type, preservation and holding time and condition on receipt;
8.3.5 pH and disinfectant residual at time of sampling (from plant records);
8.3.6 Transportation and delivery of the sample (person/carrier, conditions).
8.4 Analytical Records Data should be recorded in ink with any changes lined through such that original entry is
visible. Changes should be initialed and dated. The following information should be readily available:
8.4.1 Laboratory and persons responsible for performing analysis;
8.4.2 Analytical techniques/methods used;
8.4.3 Date and time of analysis;
8.4.4 Results of sample and quality control analyses;
8.4.5 Calibration and standards information.
8.5 Personnel Records:
Resumes and training records should be maintained for all personnel. Analyst and technician Initial Demonstration of
Capability documentation should be kept on file as well as results of proficiency testing.
8.6 Reconstruction of Data: Adequate information should be available to allow the auditor to reconstruct the final
results for compliance samples and performance evaluation samples. See Appendix H.
8.7 Computer programs: Computer programs should be verified initially and periodically by manual calculations
and the calculations should be available for inspection. Access to computer programs and electronic data should be
limited to appropriate personnel.
IV-8
-------
9. Action Response to Laboratory Results
When a laboratory is responsible, either by contract or State policy, to report sample results which would cause a
system to be out of compliance, the proper authority should be promptly notified and a request should be made for
resampling from the same sampling point immediately. See Chapter HI.
IV-9
-------
Table IV-1 Glassware Cleaning Procedures - consult the method for complete details; do not over heat volumetric
glassware ,
Method
502.2/504/504.1/524.2
505
506
507/508
508.1
508A
509
515.1/515.2
525.2
531.1/6610
547/548.1
549.1
Washing
Detergent wsish, rinse with tap
and distilled water
Detergent wash, rinse with tap
and reagent water
Rinse immediately with last
solvent used, wash with hot water
and detergent, rinse with tap
and reagent water
Rinse immediately with last
solvent used, wash with hot water
and detergent, rinse with tap and
reagent water
Detergent wash, rinse with tap
and reagent water or solvent rinse
no specifications, suggest the
same as 515. 1/515.2
Detergent wash, rinse with tap
and reagent water
Rinse immediately with last
solvent used, wash with hot water
and detergent, rinse with dilute
acid, tap and reagent water
Detergent wash, rinse with tap
and distilled water or solvent
rinse
. Rinse immediately with last
solvent used, wash with hot water
and detergent, rinse with tap and
reagent water
Rinse immediately with last
solvent used, wash with hot water
and detergent, rinse with tap and
reagent water
Rinse immediately with last
solvent used, wash with hot water
and detergent, rinse with tap and
reagent water
Drying
105°C for 1 hour
400°C for 1 hour or rinse with
acetone
400 °C for 1 hour or rinse with
acetone
400°G for 1 hour or rinse with
acetone
400°C for 2 hours
no specification, suggest the
same as 515. 1/515.2
105 °C for 1 hour for septa,
400°C for 1 hour for vials
400 °C for 1 hour or rinse with
acetone
air dry or muffle(no specs)
(suggest 400°C for 1 hour)
450 °C for 1 hour or rinse with
acetone
400 °C for several hours or rinse
with methanol
130°C for several hours or rinse
with methanol
IV-10
-------
Method
550/550.1
1613
Metals
Inorganics
Washing
Rinse immediately with last
solvent used, wash with hot water
and detergent, rinse with tap and
reagent water
Rinse with solvent, sonicate with
detergent for 30 minutes, rinse
sequentially with methanol, hot
tap water, methanol, acetone and
methylene chloride
Wash with detergent, rinse with
tap water, soak 4 hours in 20%
(V/V) nitric acid or dilute
nitric(~8%)/
hydrochloric(~17%), rinse with
reagent water .--.,„
Wash with detergent, rinse with
tap and reagent water (use
phosphate free detergent for
o-phosphate analysis)
Drying
400'C for 15-30 minutes or rinse
with acetone or pesticide quality
hexane
Air dry
Air dry
Air dry
IV-11
-------
Contaminant
Lead
Copper
PH
Conductivity
Calcium
Alkalinity
Ortho-
phosphate
unfiltered,
no digestion or
hydrolysis
Methodology
I
AA-Furnace
ICP-MS — .
AA-Platform
AA-Fumace
AA-Direct
ICP
ICP-MS
AA-Platform
Electrometric
Conductance
EDTA titration
AA-Direct
ICP
Titration
Elec. titration
Color, automated
ascorbic acid
Color,
ascorbic acid
Color,
phosphomolybdate
AutoSegmented Flow
Auto discrete
Ion Chromatography
EPA
200.82
200.92
200.72
200.82
200.91
150.1'
150.2'
200.72
365. 16
300.06
ASTM3
D3559-90D
D1688-90C
D1688-90A
D 1293-84
D 1125-91 A
D511-93A
D511-93B
D1067-92B
D515-88A
D4327-91
SM4 / ;"- ::
3113B
3113B
31 lie -'•'•'•
3120B
4500-H+-B
2510B
3500-Ca-D .
311 IB
3120B
2320B
4500-P-F
;4500-P-E
..,.,,__ : , • . ...
4110 :
Other
.,,.^rf- , •
I-1030-855
I-1601-85?
I-2601-905
I-2598-855
IV-14
-------
Contaminant
Silica
Temperature
Sodium
Turbidity
Methodology
Color,
molybdate blue;
auto seg. flow
Color
Molybdosilicate
Heteropoly blue
Auto, molybdate
reactive silica
ICP
Thermometric
ICP
AA-Direct
Nephelometric6
EPA
200.72
200.72
180.1
ASTM3
D859-88
SM4
4500-Si-D
4500-Si-E
4500-Si F
3120B
2550B
3111B
2130B
Other
I-1700-855
I-2700-855
GLI Method 212
FOOTNOTES
1 Methods 150.1, 150.2 and 245.2 are available from US EPA, EMSL, Cincinnati, OH 45268. The identical methods were formerly in
"Methods for Chemical Analysis of Water and Wastes," EPA-600/4-79-020, March 1983.
2 "Methods for the Determination of Metals in Environmental Samples - Supplement I," EPA-600/R-94-111, May 1994. Available at
NTIS, PB 94-184942.
3 Annual Book of ASTM Standards, Vols. 11.01 and 11.02, American Society for Testing and Materials, 1916 Race Street,
Philadelphia, PA 19103. •
* Standard Methods for the Examination ofWaterand Wastewater, 18th Edition, 1992, American Public Health Association, 1015
Fifteenth Street NW, Washington, D.C. 20005.
1 Available from Books and Open-File Reports Section, U.S. Geological Survey, Federal Center, Box 25425, Denver, CO 80225-0425.
' "Methods for the Determination of Inorganic Substances in Environmental Samples," EPA-600/R-93-100, August 1993. Available at
NTIS, PB94-121811.
7 Technical Bulletin 601 "Standard Method of Test for Nitrate in Drinking Water," July 1994, PN 221890-001, ATI Orion, 529 Main
Street, Boston, MA 02129. This method is identical to Orion WeWWG/5880, which is approved for nitrate analysis. ATI Orion
republished the method in 1994, and renumbered it as 601, because the 1985 manual "Orion Guide to Water and Wastewater
Analysis," which contained WeWWG/5880, is no longer available.
1 Method B-1011, "Waters Test Method for Determination of Nitrite/Nitrate in Water Using Single Column Ion Chromatography,"
Millipore Corporation, Waters Chromatography Division, 34 Maple Street, Milford, MA 01757.
' Method 100.1, "Analytical Method for Determination of Asbestos Fibers in Water," EPA-600/4-83-043, EPA, September 1983
Available at NTIS, PB 83-260471.
18 Method 100.2, "Determination of Asbestos Structure Over 10-/jm In Length in Drinking Water," EPA-600/R-94-134, June 1994.
Available at.NTIS, PB 94-201902.
" Industrial Method No. 129-71W, "Fluoride in Water and Wastewater," December 1972, and Method No. 380-75WE, "Fluoride in
Water and Wastewater," February 1976, Technicon Industrial Systems, Tarrytown, NY 10591.
" GLI Method 2, "Turbidity," November 2, 1992, Great Lakes Instruments, Inc., 8855 North 55th Street, Milwaukee, Wisconsin
53223
IV-15
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Table IV-3 Approved Methods for Primary Organic Chemicals [§141.24(e)]
Contaminant
Benzene
Carbon tetrachloride
Chlorobenzene .......
1 ,2-Dichlorobenzene
1 ,4-Dichlorobenzene
1 ,2-Dichloroethane
cis-1 ,2-Dichloroethylene
trans-1 ,2-Dichloroethylene
Dichloromethane
1 ,2-DichIoropropane
Ethylbenzene
Styrene l
Tetrachloroethylene
1 , 1 , 1-Trichloroethane
Trichloroethylene
Toluene
1 ,2,4-TrichIorobenzene
1 , 1-Dichloroethylene
1 , 1 ,2-TrichIoroethane
Vinyl chloride
Xylenes (total)
2,3,7,8-TCDD (dioxin)
2,4-D
Alachlor
Atrazine
Benzo (a)py rene
Carboftiran
Chlonlane
Method3
502.2,524.2
502.2,524.2,551
502.2, 524.2
502,2,"524.2
502.2,524.2 '••
502.2,524.2 ',
502.2, 524.2
502.2, 524.2 .,
502.2,524.2 "V ..
502.2,524.2
502.2,524.2
502.2,524.2 •-'•.- :
502.2, 524.2, 551 '
502.2,524.2,551 , ,
502.2,524.2,551
502.2,524.2
502.2,524.2 . -
502.2,. 524.2
502.2, 524.2 • ,
502.2,524.2
502.2, 524.2
1613' ' '
515.2,515.1,555
5051, 507,508.1, 525.2
505', 507, 508.1,525.2
525.2, 550, 550.1
531.1,6610
505,508,508.1,525.2
IV-16
-------
Contaminant
Dalapon „ - ,
Di(2-ethylhexyl)adipate
Di(2-ethylhexyl)phthalate
Dibromochloropropane (DBCP)
Dinoseb .,
Diquat
Endothall
Endrin
Ethylene dibromide (EDB)
Glyphosate
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Hexachlorocyclopentadiene
Lindane
Methoxychlor
Oxamyl
PCBs (as decachlorobiphenyl)2
(as Aroclors)
Pentachlorophenol
Picloram
Simazine
2,4,5-TP (Silvex)
Toxaphene
Total Trihalomethanes
Method3
515.1,552.1
506,525.2
506, 525.2
504.1,551
515.2,515.1,555
549.1
548.1
505, 508, 508.1, 525.2
504.1,551
547, 6651
505,508,508.1,525.2
505,508,508.1,525.2
505, 508, 508.1, 525.2
505,508,508.1,525.2
505,508,508.1,525.2
505,508,508.1,525.2
531.1, 6610
508A
505, 508
515.1, 515.2, 525.2, 555
515.1, 515.2, 555
505', 507, 508.1, 525.2
515.1, 515.2, 555
505, 508, 525.2
502.2, 524.2, 551
1 A nitrogen-phosphorous detector should be substituted for the electron capture detector in Method 505 (or another
approved method should be used) to determine alachlor, atrazLne and simazine, if lower detection limits are
required.
2 PCBs are qualitatively identified as Aroclors and measured for compliance purposes as decachlorobiphenyl using
Method 508A.
3 Methods 502.2, 505, 507, 508, 508A, 515.1 and 531.1 are in Methods for the Detertninatinn nf Organic
Compounds in Drinking Water, EPA-600/4-88-039, December 1988, Revised, July 1991. Methods 506, 547, 550,
IV-17
-------
550.1 and 551 are in Methods for the Determination of Organic Compounds in Drinking Water - Supplemerrt T,
EPA-600-4-90-020, July 1990. Methods 515.2, 524.2, 548.1, 549.1, 552.1 and 555 are in Mgrtuvk for the
Defarminntinn of Organic Compounds in Drinking Water - Supplement TT, EPA-600/R-92-129, August 1992.
Method 1613, Tel-ra-Thmiigli Pete- Chlorinated Dinxiris antl Fiirans hy Tsotopic Dilution HRflC/HRMS, EPA-81/B-
94-003, October 1994 These documents are available from the National Technical Information Service, NTIS
PB91-231480, PB91-146027 and PB92-207703 and PB95-104774, U.S. Department of Commerce, 5285 Port Royal
Road, Springfield, Virginia 22161. The toll-free number is 800-553-6847. Method 1613 is available from USEPA
Office of Water Resource Center (RC-4100), 401 M. Street S.W., Washington, D.C. 20460. The phone number is
202-260-7786. EPA Methods 504.1, 508.1 and 525.2 are available from US EPA NERL, Cincinnati, OH 45268.
The phone number is (513)-569-7586. Method 6651 is contained in the 18th edition of Standard Methods for the
Examination of Water and Wastewater, 1992, and Method 6610 is contained in the Supplement to the 18th edition of
Standard Methods for the Examination of Water and Wastewater, 1994, American Public Health Association, 1015
Fifteenth Street NW, Washington, D.C. 20005.
IV-18
-------
Table IV-4 Approved Methods for "Unregulated" Contaminants (§141.40) L
.-.'•'... - " , !
Regulations specified in §141.40 require monitoring for certain contaminants to which maximum contaminant
levels do not apply. These chemicals are called "unregulated" contaminants, and presently include sulfate, 34
volatile organic-chemicals (VOGs) and 13 synthetic organic chemicals (SOCs).
Analysis for the 34 unregulated VOCs listed under paragraphs (e) and Q of §141.40 shall be conducted using
the following recommended methods, or their equivalent as determined by EPA.
"Unregulated!1 VOC Contaminants
Chloroform
Bromodichloromethane
Bromoform
Chlorodibromomethane
Bromobenzene
Bromomethane
Ghloroethane
Chloromethane
o-Chlorotoluene
p-Chlorotoluene
Dibromomethane
m-Dichlorobenzene
1 , 1-Dichlbf oethane
1 ,3-Dichloropropane
2,2-Dichloropropane
1 , 1-Dichloropropene
1,3-Dichloropropene
1,1,2,2-Tetrachloroethane
1 , 1 , 1 ,2-Tetrachloroethane
1 ,2,3-Trichloropropane
Method
502.2, 524.2, 551
502.2, 524.2, 551
502.2,524.2,551
502.2,524.2,551
502.2, 524.2
502.2, 524.2
502.2,524.2
502.2, 524.2
502.2, 524.2
502.2, 524.2
502.2,524.2
502.2, 524.2
502.2, 524.2
502.2, 524.2
502.2,524.2
502.2, 524.2
502.2, 524.2
502.2, 524.2
502.2, 524.2
502.2, 524.2, 504.1
State Discretionary Contaminants
Bromochloromethane
n-Butylbenzene
METHODS
502.2, 524.2
502.2, 524.2
IV-19
-------
State Discretionary Contaminants
sec-Butylbenzene
tert-Butylbenzene
Dichlorodifluoromethane
Fluorotrichloromethane
Hexachlorobutadiene
Isopropylbenzene
p-Isopropyltoluene
Naphthalene
n-Propylbenzene
1 ,2,3-Trichlorobenzene
1 ,2,4-Trimethylbenzene
1 ,3,5-Trimethylbenzene
METHODS
502.2,524.2
502.2, 524.2
502.2*524.2
502.2,524.2
502.2, 524.2
502.2,524.2
502.2,524.2
502.2, 524.2
502.2, 524.2
502.2, 524.2
502.2, 524.2
502.2,524.2
Analysis for the 13 unregulated SOCs listed under paragraph (n)(ll) of §141.40 shall be conducted using the
following recommended methods.
"Unregulated" SOC Contaminants
Aldicarb
Aldicarb sulfone
Aldicarb sulfoxide
Aldrin ;
Butachlor
Carbaryl
Dicamba
Dieldrin
3-Hydroxycarbomran
Methomyl
Metolachlor
Metribuzin
Propachlor
Methods
531.
531.
531.
505,
507,
531.
515.
505,
531.
531.
507,
507,
508,
1, 6610*
1,6610*
1,6610*
508, 525.2, 508.1
525.2
1, 6610*
1,515.2,555
508,525.2,508.1
1, 6610*
1, 6610*
525.2,508.1
525.2,508.1
525.2,508.1
IV-20
-------
Analysis for the unregulated inorganic contaminant listed under paragraph (n)(12) of §141.40 shall be conducted
using the following recommended methods.
"Unregulated" Inorganic
Contaminants
Nickel
Sulfate
Methods
EPA
200.7
200.8
200.9
300.0
375.2
ASTM
D4327-91
SM
3120B
3111B
3113B
4110B
4500-S04-F
4500-SO4-C,D
*A Standard Methods method.
Sources for the Standard Methods and ASTM sulfate methods are referenced above under methods for inorganic
chemicals. The EPA methods are contained in "Methods for the Determination of Inorganic Substances in
Environmental Samples," EPA-600/R-93-100, August 1993, which is available at NTIS, PB94-121811.
IV-21
-------
Table IV-5 Approved Methods for Disinfectant Residuals
Public water systems must measure residual disinfectant concentrations with one of the analytical methods in the
following table. The methods are contained in the 18th edition of Standard Methods for the Examination of Water
and Wastewater.
Residual1
Free Chlorine2
Total Chlorine2
Chlorine Dioxide
Ozone
Methodology
Amperometric Titration
DPD Ferrous Titrimetric
DPD Colorimietric
Syringaldahyde (FACTS)
Amperometric Titration
Amperometric Titration
(low level mtsasurement)
DPD Ferrous Titrimetric
DPD Colorimetric
lodometric Electrode
Amperometric Titration
DPD Method
Amperometric Titration
Indigo Method
SM3
4500-C1 D
4500-C1 F
4500-C1 G
4500-C1 H
4500-C1D
4500-C1 E
4500-C1 F
4500-C1G
4500-C1I
4500-C1O2 C
4500-C102 D
4500-C10, E
4500-0, B
Footnotes
1 If approved by the State, residual disinfectant concentrations for free chlorine and combined chlorine also may be
measured by using DPD colorimetric test kits.
2 Free and total chlorine residuals may be measured continuously by adapting a specified chlorine residual method
for use with a continuous monitoring instrument provided the chemistry, accuracy, and precision of the measurement
remain the same. Instruments used for continuous monitoring must be calibrated with a grab sample measurement at
least every five days, or with protocol approved by the State.
3 Standard Methods for the Examination of Water and Wastewater, 18th Edition, 1992
IV-22
-------
Table IV-6 Recommended Methods for Secondary Drinking Water Contaminants
Analyses of aluminum, chloride, color, copper, fluoride, foaming agents, iron, manganese, odor, silver, sulfate,
total dissolved solids (TDS) and zinc to determine compliance under §143.3 may be conducted with the methods in
the following Table. Criteria for analyzing aluminum, copper, iron, manganese, silver, and zinc samples with
digestion or directly without digestion, and other mandatory procedures are contained in the Technical Notes in
Section IV of this document. Measurement of pH may be conducted with one of the methods listed above in
Section I under "Methods for Inorganic Chemicals."
Contaminant
Aluminum
Chloride •
Color
Foaming Agents
Iron
Manganese
Odor
Silver
Sulfate
TDS
Zinc
EPA
200.73
200.83
200.93
300.04
200.73
200.9s
200.73
200.83
200.93
200.73
200.83
200.93
300.04
375.2"
200.73
200.83
ASTM1
D4327-91
D4327-91
SM2
3120B
3113B
3111D
4110B
4500-Cr-D
2120B
5540C
3120B
3111B
3113B
3120B
311 IB
3113B
2150B
3120B
3111B
3113B
4110B
4500-SO4-F
4500-SO4-C,D
2540C
3120B
3111B
Other
I-3720-856
IV-23
-------
"Footnotes .
1 AnnualBook ofASTM Standards, Vols. 11.01 and 11.02, American Society for Testing and Materials, 1916 Race
Street, Philadelphia, PA 19103.
z Standard Methods for the Examination of Water and Wastewater, 18th Edition, 1992, American Public Health
Association, 1015 Fifteenth Street NW, Washington, D.C. 20005.
3 "Methods for the Determination of Metals in Environmental Samples - Supplement I," EPA-600/R-94- 111, May
1994. Available at NTIS, PB94-184942.
4 "Methods for the Determination of Inorganic Substances in Environmental Samples," EPA-600/R-93-100, August
1993. Available at NTIS, PB94-121811.
5 Industrial Method No. 129-71W, "Fluoride in Water and Wastewater," December 1972, and Method No. 380-
75WE, "Fluoride in Water and Wastewater," February 1976, Technicon Industrial Systems, Tarrytown, NY 10591.
6 Available from Books and Open-File Reports Section, U.S. Geological Survey, Federal Center, Box 25425,
Denver, CO 80225-0425.
IV-24
-------
Table IV-7 Preservation and Holding Times for Regulated Parameters
Parameter/
Method
Metals
(except Hg)
Mercury
Alkalinity
Asbestos
Chloride
Residual
Disinfectant
Color
Conductivity
Cyanide
Fluoride
Foaming Agents
Nitrate
(chlorinated)
Nitrate
(non chlorinated)
Nitrite
Odor
pH
o-Phosphate
Silica
Solids (TDS)
Sulfate
Preservative
HN03pH<2
HN03pH<2
Cool, 4C
Cool, 4C
none
none
Cool, 4C
Cool, 4C
Cool, 4C,
Ascorbic acid (if
chlorinated),
NaOHpH>12
none
Cool, 4C
Cool, 4C
Cool, 4C,
H2SO4, pH<2
Cool, 4C
Cool, 4C
none
Filter
immediately,
Cool, 4C
Cool, 4C
Cool, 4C
Cool, 4C
Sample Holding
Time
6 months
28 days
14 days
48 hours
28 days
immediately
48 hours
28 days
14 days
28 days
48 hours
28 days
" 14 days
48 hours
24 hours
immediately '
48 hours
28 days
7 days
28 days
Extract Holding
Time
•
Suggested
Sample Size
1L
100 mL
100 mL
50 mL
200 mL
50 mL
100 mL
1L
300 mL
100 mL
100 mL
50 mL
200 mL
25 mL
50 mL
100 mL
100 mL
50 mL
Type of
Container
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Plastic or Glass
Glass
Plastic or Glass
Plastic or Glass
Plastic
Plastic or Glass
Plastic or Glass
IV-25
-------
Parameter/
Method
Temperature
Turbidity
502.2
504.1
505
506
507
508
508A
508.1
515.1
515.2
524.2
Preservative
none
Cool, 4C
Sodium
Thiosulfate
or Ascorbic
Acid, 4C, HC1
pH<2
Sodium
Thiosulfate
Cool, 4C,
Sodium
Thiosulfate
Cool, 4C
Sodium <
Thiosulfate
Cool, 4C, Dark
Sodium
Thiosulfate
Cool, 4C, Dark
Sodium
Thiosulfate
Cool, 4C, Dark
Cool, 4C
Sodium Sulfite
HClpH<2
Cool, 4C
Sodium
Thiosulfate
Cool, 4C, Dark
Sodium
Thiosulfate
HC1PH<2
Cool, 4C, Dark
Ascorbic Acid
HClpH<2,
Cool 4C
Sample Holding
Time
immediately
48 hours
14 days
14 days
14 days
(7 days for
Heptachlor)
14 days
14 days(see
method for
exceptions)
7 days (see
method for
exceptions)
14 days
14 days (see
method for
exceptions)
14 days
14 days
14 days
Extract Holding
Time
4C, 24 hours
4C, 24 hours
4C, dark
14 days
4C, dark
14 days
4C, dark
14 days
30 days
30 days
4C,dark
28 days
<;4C, dark
14 days
Suggested
Sample Size
1L
100 mL
40-120 mL
40 mL
40 mL
1L
1 L
1L
1L
1L
1L
1L
40-120 mL
Type of
Container
Plastic or Glass
Plastic or Glass
Glass with Teflon
Lined Septum
Glass with Teflon
Lined Septum
Glass with Teflon
Lined Septum
Amber Glass with
Teflon lined Cap
Amber Glass with
Teflon Lined Cap
Glass with Teflon
Lined Cap
Glass with Teflon
Lined Cap
Glass with Teflon
Lined Cap
Amber Glass with
Teflon Lined Cap
Amber Glass with
Teflon Lined Cap
Glass with Teflon
Lined Septum
IV-26
-------
Parameter/
Method
525.2
531.1, 6610
547
548.1
• ,-
549.1
550, 550.1
551
555
1613B
Preservative
Sodium Sulfite,
Dark,
Cool, 4C, HC1
pH<2
Sodium
Thiosulfate,
Monochloroaceti
c acid, pH<3,
Cool, 4C
Sodium
Thiosulfate
Cool, 4C
Sodium
Thiosulfate
(HClpH 1.5-2 if
high biological
activity)
Cool, 4C, Dark
Sodium
Thiosulfate,
(H2S04pH<2if
biologically
active)
Cool, 4C, Dark
Sodium
Thiosulfate
Cool, 4C, HC1
pH<2
Sodium
Thiosulfate,
Sodium Sulfite,
Ammonium
Chloride, or
Ascorbic Acid,
HCL pH 4.5-5.0
Cool, 4C
Sodium Sulfite
HC1, pH^2
Dark, Cool 4C
Sodium
Thiosulfate
Cool, 0-4C,
Dark
Sample Holding
Time
14 days (see
method for
exceptions)
Cool 4C 28 days
14 days(18
mo.frozen)
7 days
7 days
^
7 days
14 days
14 days
Extract Holding
Time
30 days from
collection
14 days <4C
21 days
550, 30 days
550.1, 40 days
Dark, 4C
Recommend
40 days
Suggested
Sample Size
1L
60 mL
60 mL
2 250 mL
, _ j
;> 250mL
1L
s 40 mL
z 100 mL
1L
Type of
Container
Amber Glass with
Teflon Lined Cap
Glass with Teflon
Lined Septum
Glass with Teflon
Lined Septum
Amber Glass with
Teflon
Lined Septum
High Density
Amber Plastic or
Silanized Amber
Glass .
Amber Glass with
Teflon Lined Cap
Glass with Teflon
Lined Septum
Glass with Teflon
lined cap
Amber Glass with
Teflon Lined Cap
IV-27
-------
Table IV-8 Detection Limit Requirements in the CFR (mg/I)
Inorganics
Asbestos
Cyanide
Fluoride
Nitrate
Nitrite
MCL*
7MFL
0.2
4.0
10
1
MCLG
7MFL
0.2
10
1
Detection Limit Required to
Composite [§141.23(a)(4)]
1.4 MFL
0.04
0.8
2
0.2
* The monitoring trigger for the inorganics is the
MCL except for both nitrate and nitrite, which are 1/2 the MCL
Metals
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Copper**
Lead**
Mercury
Selenium
Thallium
MCL*
0.006
0.05
2
0.004
0.005
0.1
1.3
0.015
0.002
0.05
0.002
MCLG
0.006
-_
2
0.004
0.005
0.1
1.3
zero
0.002
0.05
0.0005
Detection Limit Required to
Composite [§141.23(a)(4)]
0.001
0.01
0.4
0.0008
0.001
0.02 ' . ..
0.001
0.02 (for direct aspiration AA)
0.001
0.0004
0.01
0.0004
* The monitoring trigger for metals is
the MCL unless compositing, then 1/5 MCL is required
**Action Level
IV-28 /t
-------
TABLE IV-8 Detection Limit Requirements in the CFR (mg/L)
Volatile Organics*
THMs
Benzene
Carbon tetrachloride
Chlorobenzene
o-Dichlofobenzene
p-Dichlorobenzene
1 .2-Dichloroethane
1 , 1-Dichloroethylene
c-1 ,2-Dichloroethylene
t-1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
Ethylbenzene
Styrene
Tetrachloroethylene
Toluene
1 ,2,4-TrichIorobenzene
1 , 1 , 1-Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
Vinyl chloride
Xylenes
MCL
0.10
0.005
0.005
0.1
0.6
0.075
0.005
0.007
0.07
0.1
0.005
0.005
0.7
0.1
0.005
1
0.07
0.2
0.005
0.005
0.002
10
MCLG
NA
zero
zero
0.1
0.6
0.075
zero
0.007
0.07
0.1
zero
zero
0.7
0.1
zero
1
0.07
0.2
0.003
zero
zero
10
Required MDL
NA
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0005
0.0004
0.0005
* A laboratory must be able to achieve an MDL of 0.5 yUg/L to be
certified to analyze samples for compliance monitoring [§141.24(f)(17)(i)(E) and (ii)(C)].
This is also the monitoring trigger for VOCs [§141.24(f)(ll)].
IV-29
-------
TABLE IV-8 Detection Limit Requirements in the CFR (mg/1)
SOCs
Alachlor
Atrazine
Benzo(a)pyrene
Carbofuran
Chlordane
2,4-D
Di(2-ethylhexyl)adipate
Di(2-ethylhexyl)phthalate
Dibromochloropropane (DBCP)
Dalapon
Dinoseb
Dioxin (2,3,7,8-TCDD)
Diqiiat
Endothall
Enclrin
Ethylencdibromide (EDB)
Glyphosate
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Hexachlorocyclopentadiene
Lindane
Methoxychlor
Oxamyl
PCBs (as decachlorobiphenyl)
Pentachlorophenol
Picloram
Simazine
Toxaphene
2,4,5-TP (Silvex)
MCL
0.002
0.003
0.0002
0.04
0.002
0.07
0.4
0.006
0.0002
0.2
0.007
3xlO-8
0.02
0.1
0.002
0.00005
0.7
0.0004
0.0002
0.001
0.05
0.0002
0.04
0.2
0.0005
0.001
0.5
0.004
0.003
0.05
MCLG
zero
0.003 .
zero
0.04
zero
0.07
0.4
zero
zero
0.2
0.007
zero
0.02
0.1
0.002
zero
0.7
zero
zero
zero
0.05
0.0002
0.04
0.2
zero
zero
0.5
0.004
zero
0.05
Monitoring Trigger*
0.0002
0.0001
0.00002
0.0009
0.0002
0.0001
0.0006
0.0006
0.00002
0.001
0.0002
5xlO-9
0.0004
0.009
0.00001
0.00001
0.006
0.00004
0.00002
0.0001
0.0001
0.00002
0.0001
0.002
0.0001
0.00004
0.0001
0.00007
0.001
0.0002
*The monitoring triggers for SOCs listed in the regulat
are not required by regulation for certification
ion are also required for compositing but
[§141.24(g)(7), (10)© and (18)].
IV-30
-------
Table IV-9 Performance Evaluation Sample Acceptance Criteria in the CFR
Primary and Secondary Drinking Water Regulations [§141.23(k)(3)(ii) and 141.24(f)(17) and (19)]
•
Regulated Parameter
METALS 1
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Copper
Iron
Lead
Manganese
Mercury
Selenium
Silica
Silver
Sodium
Thallium
Zinc
MCL/ [SMCL]
mg/L
[0.05-0.2]
0.006
0.05
2
0.004
0.005
-
0.1
1.3/90%
[1.0]
[0.3]
0.015/90%
[0.05]
0.002
0.05
-
[0.1]
20'
0.002
[5.0]
MCLG
mg/L
-
0.006
-
2
0.004
0.005
-
0.1
1.3
-
zero
-
0.002
0.05
-
-
0.0005
-
Acceptance
Limit
±30%
±15%
±15%
±20%
±15%
±10%
±30%
±30%
±20%
±30%
1 Recommended Level
IV-31
-------
Regulated Parameter
INORGANICS
Alkalinity
Asbestos
Chloride
Residual Disinfectant
Color
Conductivity
Corrosivity
Cyanide
Fluoride
Foaming Agents
Nitrate (as N)
Nitrite (as N)
Nitrate/Nitrite (as N) •
Odor
pH
o-Phosphate
Solids(TDS)
Sulfete
Temperature
MCL/ [SMCL]
mg/L
7MF/L>10u
[250]
detectable
[15cu]
-
[non-corrosive]
0.2
4.0
[2.0]
[0.5]
10
1
10
[3ton]
6.5-8.5
[6.5-8.5]
-
[500]
deferred
[250]
-
MCLG
mg/L
-
7MF/L>10u
-
-
-
-
-
0.2
-
-
10
1
10
-
- •
•>
-
deferred
-
Acceptance
Limit
2 Std Dev
±25%
±10%
±10%
±15%
IV-32
-------
Regulated Parameter
VOLATILES
Trihalomethanes(Total)
Benzene
Carbon tetrachloride
Chlorobenzene
p-Dichlorobenzene
o-Dichlbrobenzene
1 ,2-Dichloroethane
1 , 1 -Dichlorqethylene
c-1 ,2-Dichloroethylene
t-1 ,2-Dichloroethylene
Dichloromethane
1 ,2-Dichloropropane
Etfaylbenzene
Styrene
Tetrachloroethylene
Toluene
1 ,2,4-Trichlorobenzene
1 , 1 , 1 -Trichloroethane
1 , 1 ,2-Trichloroethane
Trichloroethylene
Vinyl chloride
Xylenes(Total)
MCL/ [SMCL]
mg/L
0.10
0.005
0.005
0.1
0.075
[0.005]
0.6
0.005
0.007
0.07
0.1
0.005
0.005
0.7
0.1
0.005
1
0.07
0.2
0.005
0.005
0.002
10
MCLG
mg/L
zero
zero
0.1
0.075
0.6
zero
0.007
0.07
0.1
zero
zero
0.7
0.1
zero
1
0.07
0.2
0.003
zero
zero
10
Acceptance
Limit
±20%
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
±40%
*
IV-33
-------
Regulated Parameter
SYNTHETIC ORGANICS
Alachlor
Aldicarb
Aldicarb Sulfoxide
Aldicarb Sulfone
Atrazine
Carbofuran
Chlordane
2,4-D
Dalapon
Dibromochloropropane(DBCP)
Dinoseb
Diqiiat
Endothall
Endrin
Ethylenedibromide(EDB)
Glyphosate
Heptachlor
Heptachlor epoxide
Lindane
Methoxychlor
Oxamyl (Vydate)
Pentachlorophenol
MCL/ [SMCL]
mg/L
0.002
Postponed
Postponed
Postponed
0.003
0.04
0.002
0.07
0.2
0.0002
0.007
0.02
0.1
0.002
0.00005
0.7
0.0004
0.0002
0.0002
0.04
0.2
0.001
MCLG
mg/L
zero
Postponed
Postponed
Postponed
0.003
0.04
zero
0.07
0.2
zero
0.007
0.02
0.1
0.002
zero
0.7
zero
zero
0.0002
0.04
0.2
zero
Acceptance
Limit
±45%
2 Std Dev
2 Std Dev
2 Std Dev
± 45%
±45%
±45%
±50%
2 Std Dev
±40%
2 Std Dev
2 Std Dev
2 Std Dev
±30%
±40%
2 Std Dev
±45%
±45%
±45%
±45%
2 Std Dev
±50%
IV-34
-------
Regulated Parameter
Picloram
Simazine
Toxaphene
2,4,5-TP(Silvex)
Hexachlorobenzene
Hexachlorocyclopentadiene
Benzo(a)pyrene
PCBs
(as decachlorobiphenyl)
2,3,7,8-TCDD(Dioxin)
Acrylamide
Epichlorohydrin
Di(2-ethylhexyl)adipate
Di(2-ethylhexyl)phthalate
MCL/ [SMCL]
mg/L
0.5
0.004
0.003 !
0.05
0.001
0.05
0.0002
0.0005
3xlO'8
Treatment
Treatment
0.4
0.006
MCLG
mg/L
0.5
0.004
zero
0.05
!
zero
0.05
zero
zero
zero
zero
zero
0.4
zero
Acceptance
Limit
2 Std Dev
2 Std Dev
±45%
±50%
2 Std Dev
2 Std Dev
2 Std Dev
0-200%
2 Std Dev
NA
NA
2 Std Dev
2 Std Dev
* the acceptance limits for VOCs are ±20% at ;>0.010mg/L and ±40% at <0.010mg/L
NA - Not Applicable
IV-35
-------
Laboratory
Location
Evaluator
Date
PHYSICAL FACILITY
Item
Environment •-•---.
Heatmg/Cooling/Humidity
Lighting
Ventilation/Exhaust hoods
Cleanliness
Electrical and water services
Workspace - -----
Separation of incompatible testing areas
Controlled access where appropriate
Housekeeping
Unencumbered access
Adequate work space
Storage
Chemicals properly stored and dated
Standards properly stored, dated and
labeled with concentration,
preparer's name and solvent, origin,
purity & traceability
Computers & automated equipment
Safety procedures
Acceptable
Yes No
^_., .-..- ,,.. ,.- - .
•••••-•• - • •---•
Comments ~
'
----- - ------
-- -•- -- -.,-.«— .~.. -- , .- - ,.,,...•.,,-,
------- •-:'---•«• .-..--- -.-.••-.*•. .-. -• ----- -- --- ••-•'
------••-- -- ' • • — -' - u -- * •
.. . ., .....
IW38
-------
Laboratory
Location
E valuator
Date
PERSONNEL (Use additional paper if necessary.)
Position/ Title
Laboratory
Director
Manager
Supervisors
Instrument
Operators
AA
TEM
HPLC
GC
ICP
GC/MS
1C
Other analysts
Name
An organization chart available
QA manager has line authority
Personnel job descriptions and resumes
available
Personnel training documented
Education Level
Degree/Major*
Yes No
Specialized
Training
Present
Specialty
Experience
Comments
*If the major is not in chemistry, list hours of college level courses in chemistry.
IV-39
-------
Laboratory
Location
E valuator
Date
QUALITY ASSURANCE AND DATA REPORTING
Item
QApIan
Organization
Sampling
SOPs available and used
Preservation
Containers
Holding times
Samplers trained
Sample Rejection
Laboratory sample handling
Log in procedure
Bound log book or secure
computer log in
Storage
Tracking
Analytical Methods
Written methods available
Approved methods used
SOPs available and used
Calibration
Type and frequency
Source of standards
Data comparability
Instrument tuning
Blanks
Trip
Field
Method
Method Detection Limits
Initial
Frequency
Acceptability
Precision and Accuracy
Initial
Frequency
Acceptability
Control charts
Laboratory fortified blanks
Matrix duplicates
Comments
.......
Satisfactory
Yes No
IV-40
-------
Item
Other QC Checks
Performance check samples
Internal and surrogate standards
Matrix spikes and replicates
Qualitative Identification/
Confirmation
Performance Evaluation
Samples Analyzed
Data Reduction and Validation
Calculations
Transcription
Significant Figures
Validation
Preventive Maintenance
Records Retention
Corrective Action
Comments
Satisfactory
Yes No
IV-41
-------
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CO ><
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CA
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Analytical Balance
0.1 mg readability
Stable base
ASTM type 1 or 2 wei
Service contracts
J
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1
Magnetic Stirrer
1 Variable speed, TFEc
1
^
rl
pH Meter
Accuracy +0.1 units
T inA ^^ Untfo,*^r
ji ' -" "-* \/JL vein^'ji j
Usable with specific io
en
II
Conductivity Meter
Readable in ohms or ir
Range of 2 ohms to 2 1
Line or battery
| Hot Plate - temp centre
i
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in
X
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ai f^1
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§ r°
0H
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•§
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ii
Color Standards
To verify wavelengths
Should cover 200-800
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SI
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Drying Oven
Gravity or convection
Controlled from room
higher(±2°C)
f
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Muffle Furnace
To 450°C for cleaning
O
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2 A
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Thermometer
Mercury filled Celsius
1°C or finer subdivisio
NBS Certified or traces
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Borosilicate
Volumetrics should be
%
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Spectrophotometer
Range 400 - 700 nm
Band width - < 20 nm
Use several size & sha]
Pathlength 1 -5cm
1
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Filter Photometer
Range 400 - 700 nm
Bandwidth 10 -70 nm
Use several size & sha]
Pathlength 1 - 5 cm
Disinfectants
H
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III
O E 55
Specific Ion Meter
Accuracy ± 1 mV
-------
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Method
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o »
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Nitrous Oxide - comm. grac
a "*3
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Manufacturer
T3
s
£1
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£?
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15
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Gas Chromatograph
Split/splitless injection
Oven temp, control ± 0.2°C
Recorder, hard copy
Oven temp, programmer
Sub-ambient accessory
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Chapter V
Critical Elements for Microbiology
Note: This chapter uses the term "must" to refer to certification criteria that are required by the National Primary
Drinking Water Regulations which include the approved drinking water methods. The term "should" is used for
procedures that, while not specifically required by the regulations, are considered good laboratory practice for quality
assurance. To assure the validity of the data, it is critical that laboratories observe both the regulatory and non-regulatory
criteria. Certification Officers have the prerogative to refuse certification if the quality control data are judged
unsatisfactory or insufficient.
Note: References to Standard Methods for the Examination of Water and Wastewater are to the 18th edition (1992)
1. Personnel
1.1 Supervisor/Consultant
The supervisor of the microbiology laboratory should have a bachelor's degree in microbiology, biology, or equivalent.
Supervisors who have a degree in a subject other than microbiology should have had at least one college-level
microbiology laboratory course in which environmental microbiology was covered. In addition, the supervisor should
have a minimum of two weeks training at a Federal agency, State agency, or academic institution in microbiological
analysis of drinking water or, 80 hours of on-the-job training in water microbiology at a certified laboratory, or other
training acceptable to the State or EPA. If a supervisor is not available, a consultant having the same qualifications may
be substituted, as long as the laboratory can document that the consultant is acceptable to the State and is present on-site
frequently enough to satisfactorily perform a supervisor's duties.
The laboratory supervisor has the responsibility to insure that all laboratory personnel have demonstrated their ability to
satisfactorily perfonn the analyses to which they are assigned and that all data reported by the laboratory meet the required
quality assurance and regulatory criteria.
1.2 Analyst (or equivalent job title)
The analyst should perform microbiological tests with minimal supervision, and have at least a high school education.
In addition, the analyst should have a minimum of at least three months of bench experience in water, milk, or food
microbiology. The analyst should also have training acceptable to the State (or EPA for non-primacy States), in
microbiological analysis of drinking water and a minimum of 30 days of on-the-job training under an experienced analyst.
Analysts should take advantage of workshops and training programs that may be available from State regulatory agencies
and professional societies. Before analyzing compliance samples, the analyst must demonstrate acceptable results for
precision, specificity and satisfactory analysis on unknown samples.
1.3 Waiver of Academic Training Requirement
The certification officer may waive the need for the above specified academic training, on a case-by-case basis, for highly
experienced analysts.
1.4 Personnel Records
Personnel records which include academic background, specialized training courses completed and types of
microbiological analyses conducted, should be maintained on laboratory analysts
2. Laboratory Facilities
Laboratory facilities should be clean, temperature and humidity controlled, and have adequate lighting at bench tops.
They should have provisions for disposal of microbiological waste. Laboratory facilities should have sufficient bench-top
area for processing samples; storage space for media, glassware, and portable equipment; floor space for stationary
equipment (incubators, water baths, refrigerators, etc.); and associated area(s) for cleaning glassware and sterilizing
materials.
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3. Laboratory Equipment and Supplies
The laboratory must have the equipment and supplies needed to perform the approved methods for which
certification has been requested.
3.1 pHMeter
3.1.1 Accuracy and scale graduations must be within ±0.1 units.
3.1.2 pH buffer aliquots should be used only once.
3.1.3 Electrodes should be maintained according to the manufacturer's recommendations.
QC 3.1.4 pH meters should be standardized before !each use period with pH 7.0 and either pH 4.0 or 10.0 standard
buffers, whichever range covers the desired pH of the media or reagent. The date and buffers used should be
recorded in a log book.
QC 3.1.5 Commercial buffer solution containers should be dated upon receipt, and when opened. Buffers should
be discarded before the expiration date.
3.2 Balance (top loader or pan)
3.2.1 Balances should have readability of 0.1 g
QC 3.2.2 Balances should be calibrated monthly using ASTM type 1, 2, or 3 weights (minimum of three traceable
weights which bracket laboratory weighing needs). (ASTM, 1916 Race St.., Philadelphia, PA 19103) Non-
reference weights should be calibrated every six months with reference weights.
QC 3.2.3 Service contracts or internal maintenance protocols and maintenance records should be available.
Maintenance should be conducted annually at a minimum. A record of the most recent calibration should be
available for inspection. Correction values should be on file and used. A reference weight should be re-
certified if it is damaged or corroded.
3.3 Temperature Monitoring Device ,
3.3.1 Glass, dial, or electronic thermometers must be graduated in 0.5°C increments (0.2°C increments for
tests which are incubated at 44.5°C) or less. The fluid column in glass thermometers should not be separated.
Dial thermometers that cannot be calibrated should not be used.
QC 3.3.2 Calibrations of glass and electronic thermometers should be checked annually and dial thermometers
quarterly, at the temperature used, against a reference National Institute of Standards and Technology (formerly
National Bureau of Standards [NBS]) thermometer or one that meets the requirements of NBS Monograph SP
250-23. The calibration factor should be indicated on the thermometer. Also, the laboratory should record the
date the thermometer was calibrated and the calibration factor in a QC record book
QC 3.3.3 If a thermometer differs by more than 1°C from the reference thermometer, it should be discarded.
Reference thermometers should be recalibrated every three years.
QC 3.3.4 Continuous recording devices that are used to monitor incubator temperature should be recalibrated at
least annually. A reference thermometer that meets the specifications described in paragraph 3.3,2 should be
used for calibration.
3.4 Incubator Unit
3.4.1 Incubator units must have an internal temperature monitoring device and maintain a temperature of 35°
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±0.5°C, and if used, 44.5° ±0.2°C. For non-portable incubators, thermometers should be placed on the top
and bottom shelves of the use area with the thermometer bulb immersed in liquid (except for electronic
thermometers). If an aluminum block incubator is used, culture dishes and tubes should fit snugly. Laboratories
which use the chromogenic/fluorogenic substrate tests with air-type incubators should note the caution indicated
in 5.6.8.
QC 3.4.2 Calibration-corrected temperature should be recorded for days in use at least twice per day with readings
separated by at least 4 hours.
3.4.3 An incubation temperature of 44.5° ±0.2°C can best be maintained with a water bath equipped with a
gable cover and a pump or paddles to circulate water.
3.5 Autoclave
3.5.1 The autoclave should have an internal heat source, a temperature gauge with a sensor on the exhaust, a
pressure gauge, and an operational safety valve. The autoclave should maintain a sterilization temperature
during the sterilizing cycle and complete an entire cycle within 45 minutes when a 12-15 minute sterilization
period is used. The autoclave should depressurize slowly enough to ensure that media will not boil over and
bubbles will not form in inverted tubes.
3.5.2 Because of safety concerns and difficulties with operational control, pressure cookers should not be used.
QC 3.5.3 The date, contents, sterilization time and temperature, total time for each cycle, and analyst's initials
should be recorded each time the autoclave is used. A copy of the service contract or internal maintenance
protocol and maintenance records should be kept. Maintenance should be conducted annually at a minimum.
A record of the most recent service performed should be available for inspection.
QC 3.5.4 A maximum-temperatiire-registering thermometer or continuous recording device should be used during
each autoclave cycle to ensure that the proper temperature was reached, and the temperature recorded.
Overcrowding should be avoided. Spore strips or ampules should be used monthly to confirm sterilization.
QC 3.5.5 Automatic timing mechanisms should be checked quarterly with a stopwatch or other accurate timepiece
or time signal.
3.5.6 Autoclave door seals should be clean and free of caramelized media. Also, autoclave drain screens should
be cleaned frequently and debris removed.
3.6 Hot Air Oven
3.6.1 The oven should maintain a stable sterilization temperature of 170-180°C for at least two hours. Only
dry items should be sterilized with a hot air oven. Overcrowding should be avoided. The oven thermometer
should be graduated in 10°C increments or less, with the bulb placed in sand during use.
QC 3.6.2 The date, contents, sterilization time and temperature of each cycle, and analyst's initials should be
recorded.
QC 3.6.3 Spore strip or ampule should be used on a monthly basis to ensure sterility of items.
3.7 Colony Counter
A dark field colony counter should be iised to count Heterotrophic Plate Count colonies.
•3.8 Conductivity Meter
3.8.1 Meters should be suitable for checking laboratory reagent-grade water and readable in appropriate
M units (micromhos or microsiemens per centimeter). Use an instrument capable of measuring conductivity
V-3
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with an error not exceeding 1 % or 1 micromho per centimeter, whichever is more lenient.
QC 3.8.2 Cell constant should be determined monthly using a method indicated in Section 2510, "Conductivity,"
in Standard Methods. Monthly calibration checks using an appropriate certified and traceable low-level standard
may be substituted for determining the cell constant.
3.8.3 If an in-line unit cannot be calibrated, it should not be used to check reagent-grade water.
3.9 Refrigerator
3.9.1 Refrigerators should maintain a temperature of 1-5°C. Thermometers should be graduated in at least 1°C
increments and the thermometer bulb immersed in liquid.
QC 3.9.2 The temperature should be recorded for days in use at least once per day.
3.10 Inoculating Equipment
Sterile metal or disposable plastic loops, wood applicator sticks, sterile swabs, or sterile plastic disposable pipet
tips should be used. If wood applicator sticks are used, they should be sterilized by dry heat. The metal
inoculating loops and/or needles should be made of nickel alloy or platinum. (For the coliform test and any
other oxidase test used for the verification of membrane filter colonies, nickel alloy loops must not be used
because they may interfere with the oxidase test).
3.11 Membrane Filtration Equipment (if MF procedure is used)
3.11.1 MF units must be stainless steel, glass, or autoclavable plastic, not scratched or corroded, and must not
leak.
QC 3.11.2 If graduation marks on clear glass or plastic funnels are used to measure sample volume, their accuracy
should be checked with a standard graduated cylinder, and a record of this calibration check retained. Tolerance
should be <;2.5%.
3.11.3 A 10X to 15X stereo microscope with a fluorescent light source must be used to count sheen colonies.
3.11.4 Membrane filters must be approved by the manufacturer for total coliform water analysis. Approval
is based on data from tests for toxicity, recovery, retention, and absence of growth-promoting substances.
Filters must be cellulose ester, white, gridmarked, 47 mm diameter, and 0.45 /um pore size, or alternate pore
sizes if the manufacturer provides performance data equal to or better than the 0.45 ,wm pore size. Membrane
filters must be purchased presterilized or autoclaved for 10 minutes at 121 °C before use.
QC 3.11.5 The lot number for membrane filters and the date received should be recorded.
3.12 Culture Dishes Qoose or tiglU lids)
3.12.1 Presterilized plastic or sterilizable glass culture dishes must be used. To maintain sterility of glass
culture dishes, stainless steel or aluminum canisters, or a wrap of heavy aluminum foil or char-resistant paper,
must be used.
3.12.2 Loose-lid petri dishes should be incubated in a tight-fitting container, e.g., plastic vegetable crisper
containing a moistened paper towel to prevent dehydration of membrane filter and medium. ;
3.12.3 Opened packs of disposable culture dishes should be resealed between use periods.
3.13 Pipets
3.13.1 To sterilize and maintain sterility of glass pipets, stainless steel or aluminum- canisters should be used,
or individual pipets should be wrapped in char-resistant paper or aluminum foil.
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3.13.2 Pipets must have legible markings and should not be chipped or etched.
3.13.3 Opened packs of disposable sterile pipets should be reseated between use periods.
3.13.4 Pipets delivering volumes of 10 mL or less must be accurate within a 2.5% tolerance.
3.13.5 Calibrated micropipetters may be used if tips are sterile. Micropipetters should be calibrated
annually and replaced if the tolerance is greater than 2.5%
3.14 Culture Tubes and Closures
3.14.1 Tubes should be made of borosilicate glass or other corrosion-resistant glass or plastic.
, 3.14.2 Culture tubes and containers should be of sufficient size to contain medium plus sample without being
more than three quarters full.
3.14.3 Tube closures should be stainless steel, plastic, aluminum, or screw caps with non-toxic liners. Cotton
plugs should not be used.
3.75 Sample Containers
3.15.1 Sample containers must be wide-mouth plastic or non-corrosive glass bottles with non-leaking ground
glass stoppers or caps with non-toxic liners that should withstand repeated sterilization, or sterile plastic bags
containing sodium thiosulfate. Other appropriate sample containers may be used. The capacity of sample
containers should be at least 120 mL (4 oz.).
3.15.2 Glass stoppers must be covered with aluminum foil or char-resistant paper for sterilization.
3.15.3 Glass and plastic bottles that have not been presterilized should be sterilized by autoclaving or, for glass
bottles, by dry heat. Empty containers should be moistened with several drops of water before autoclaving to
prevent an "air lock" sterilization failure.
3.15.4 If chlorinated water is to be analyzed, sufficient sodium thiosulfate (Na^Oj) must be added to the
sample before sterilization to neutralize any residual chlorine in the water sample. Dechlorination is addressed
in Section 9060A of Standard Methods.
3.16 Glassware andPlasticware
3.16.1 Glassware must be borosilicate glass or other corrosion-resistant glass and free of chips and cracks.
Markings on graduated cylinders and pipets must be legible. Plastic items must be clear and non-toxic to
microorganisms.
QC 3.16.2 Graduated cylinders for measurement of sample volumes must have a tolerance of 2.5% or less. In lieu
of graduated cylinders, precalibrated containers that have clearly marked volumes of 2.5% tolerance may be
used. The calibration of each new lot of precalibrated containers should be validated by selecting at least one
container at random and checking the calibration using a previously verified graduated cylinder.
3.17 Ultraviolet lamp (if used)
3.17.1 The unit should be disconnected monthly and the lamps cleaned by wiping with a soft cloth moistened
with ethanol.
QC 3.17.2 If a UV lamp (254 nm) is used for sanitization, the lamp should be tested quarterly with a UV light meter
or agar spread plate. The lamp should be replaced if it emits less than 70% of its initial output or if an agar
spread plate containing 200 to 250 microorganisms, exposed to the UV light for two minutes, does not show a
count reduction of 99 % . Other methods may be used to test a lamp if data demonstrate that they are as effective
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as the two suggested methods.
4: General Laboratory Practices
Although safety criteria are not covered in the laboratory certification program, laboratory personnel should be aware
of general and customary safety practices for laboratories. Each laboratory is encouraged to have a safety plan available.
4.1 Sterilization Procedures
4.1.1 Required times for autoclaving at 121°C are listed below. The items must be at temperature for this
required amount of time. Except for membrane filters and pads and carbohydrate-containing media, indicated
times are minimum times which may necessitate adjustment depending upon volumes, containers, and loads.
Item Time (min)
Membrane filters & pads 10
Carbohydrate containing media 12-15
Contaminated test materials 30
Membrane filter assemblies 15
Sample collection bottles 15
Individual glassware 15
Dilution water blank, 15
Rinse water (0.5 - 1 L) 15-30*
* time depends upon water volume per container and autoclave load
4.1.2 Autoclaved membrane filters and pads and all media should be removed immediately after completion of
the sterilization cycle.
4.1.3 Membrane filter equipment must be autoclaved before the beginning of the first filtration series. A
filtration series ends when 30 minutes or longer elapses after a sample is filtered.
4.1.4 Ultraviolet light (254 run) may be used as an alternative to sanitize equipment, if all supplies are
presterilized and QC checks are conducted as indicated in paragraph 3.17.2. Ultraviolet light may also be used
to control bacterial carry-over between samples during a filtration series.
4.2 Sample Containers
4.2.1 See Section 6.2 for sample preservation.
QC 4.2.2 At least one sample container should be selected at random from each batch of sterile sample bottles or
other containers, and sterility confirmed by adding approximately 25 mL of a sterile non-selective broth (e.g.,
tryptic soy, trypticase soy, or tryptone broth). The broth should be incubated at 35 +0.5°C for 24 hours and
checked for growth. Resterilize if growth is detected.
4.3 Reagent-Grade Water
4.3.1 Only satisfactorily tested reagent water from stills or deionization units may be used to prepare media,
reagents, and dilution/rinse water for performing bacteriological analyses.
QC 4.3.2 The quality of the reagent water should be tested and should meet the following criteria:
Parameter Limits • Frequency
Conductivity < 2 micromhos/cni (micros iemens/cm) at Monthly
25°C
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Parameter
Limits
Pb, Cd, Cr, Cu, Ni, Zn
Not greater than 0.05 mg/L per contaminant.
Collectively, no greater than 0.1 mg/L
Total Chlorine Residual1 < 0.1 mg/L
Heterotrophic Plate Count2 < 500/mL
Frequency
Annually
Monthly
Monthly
Bacteriological Quality
of Reagent Water3
Ratio of growth rate 0.8:3.0
Annually
DPD Method should be used. Not required if source water is not chlorinated.
2 Pour Plate Method. See Standard Methods 9215B.
3 See Standard Methods, Section 9020B. This bacteriological quality test is not needed for ASTM (ASTM, 1916 Race St..,
Philadelphia, PA 19103) Types 1 reagent water, as defined in Standard Methods, Section 1080.
4.4 Dilution/Rinse Water
4.4.1 Stock buffer solution or peptone water should be prepared, as specified in Standard Methods, Section
9050C.
4.4.2 Stock buffers should be autoclaved or filter-sterilized, and containers should be labeled and dated. Stock
buffers should be refrigerated. Stored stock buffers should be free from turbidity.
QC 4.4.3 Each batch of dilution/rinse water should be checked for sterility by adding 50 mL of water to 50 mL
of a double strength non-selective broth (e.g., tryptic soy, trypticase soy or tryptose broth). Incubate at 35
±0.5°C for 24 hours and check for growth. Discard if growth is detected.
4.5 Glassware Washing
4.5.1 Distilled or deionized water should be used for final rinse.
QC 4.5.2 A glassware inhibitory residue test (Standard Methods, Section 9020B) should be performed before the
initial use of a washing compound and whenever a different formulation of washing compound, or washing
procedure, is used. In addition, batches of dry glassware should be spot-checked occasionally for pH reaction,
especially if glassware is soaked in alkali or acid (Standard Methods, Section 9020B). These tests will ensure
that glassware is at a neutral pH and is free of toxic residue.
4.5.3 Laboratory glassware should be washed with a detergent designed for laboratory use.
5. Analytical Methodology
5.7 General
5.1.1 For compliance samples, laboratories must only use the analytical methodology specified in the Total
Coliform Rule (40 CFR 141.21(f)) and the Surface Water Treatment Rule (40 CFR 141.74(a)).
5.1.2 A laboratory must be certified for all analytical methods, indicated below, that it uses for compliance
purposes. At a minimum, the laboratory must be certified for one total coliform method and one fecal coliform
or E. coli method. A laboratory should also be certified for a second total coliform method if one method cannot
be used for some drinking waters (e.g., where the water usually produces confluent growth on a plate). In
addition, for principal State laboratories and other laboratories that may enumerate heterotrophic bacteria (HPC)
for compliance with the Surface Water Treatment Rule, the laboratory must be certified for the Pour Plate
Method, the only method approved for heterotrophic bacteria.
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5.1.3 Absorbent pads must be saturated with a liquid medium (at least 2 mL of broth) and excess medium
removed by "decanting" the plate.
5.1.4 Water samples should be shaken vigorously about 25 times before analyzing.
QC 5.1.5 If no total coliform-positive result occurs during a quarter, the laboratory should perform the coliform
procedure using a known coliform-positive, fecal coliform and/or E. coli- positive control to spike the sample.
5.1.6 Sample volume analyzed for total coliforms in drinking water must be 100 mL ±2.5 mL.
5.1.7 Media
5.1.7.1 The use of dehydrated or prepared media manufactured commercially is strongly
recommended due to concern about quality control. Dehydrated media should be stored in a cool, dry
location. Caked or discolored dehydrated media should be discarded.
QC 5.1.7.2 For media prepared in the laboratory, the date of preparation, type of medium, lot number,
sterilization time and temperature, final pH, and the technician's initials should be recorded.
QC 5.1.7.3 For liquid media prepared commercially, the date received, type of medium, lot number, and
pH verification should be recorded. Medium should be discarded by manufacturer's expiration date.
QC 5.1.7.4 Each new lot of dehydrated or prepared commercial medium should be checked before use
with positive and negative culture controls, hi addition, each batch of laboratory ^prepared medium
should include positive and negative culture controls. These control organisms can be stock cultures
(periodically checked for purity) or commercially available disks impregnated with the organism.
Results should be recorded.
5.1.7.5 Prepared plates may be refrigerated in sealed plastic bags or containers. Because of potential
evaporation, they may not be kept for more than two weeks. Each bag or container should include the
date prepared or an expiration date. Broth in loose-cap tubes should be stored at <30°C no longer
than two weeks. Broth in tightly capped tubes should be stored at < 30°C no longer than three months.
When ready to use, the refrigerated sterilized medium should be incubated overnight at room
temperature; media with growth should be discarded.
QC 5.1.8 Laboratories are encouraged to perform parallel testing between a newly approved test and another EPA-
approved procedure for enumerating total coliforms for at least several months and/or over several seasons to
assess the effectiveness of the new test for the wide variety of water types submitted for analysis. During this
testing, spiking the samples occasionally with sewage or a pure culture may be necessary to ensure that some
of the tests are positive.
5.2 Membrane Filter (MF) Technique (for total coliforms in drinking water)
5.2.1 Media
5.2.1.1 M-Endo Medium broth or agar (also known as M-Endo broth MF and M-Coliform Broth) or
LES Endo agar (also known as M-Endo Agar LES) must be used in the single step or enrichment
techniques. Ensure that ethanol used in the rehydration procedure is not denatured. Medium must be
prepared in a sterile flask and a boiling water bath must be used or, if constantly attended, a hot plate
with a stir bar may be used, to bring the medium just to the boiling point. The medium must not be
boiled. pH must be 7.2 ±0.2 for LES Endo agar and 7.2 ±0.1 for M-Endo medium.
5.2.1.2 MF broth must be refrigerated no longer than 96 hours, poured MF agar plates no longer than
two weeks, and ampuled M-Endo broth in accordance with the manufacturer's expiration date. Broth,
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plates, or ampules should be discarded earlier if growth or surface sheen is observed.
QC 5.2.1.3 MF sterility check should be conducted on each funnel in use at the beginning and the end of
each filtration series by filtering 20-30 mL of dilution water through the membrane filter and testing
for growth. If the control indicates contamination, all data from affected samples must be rejected and
an immediate resampling should be requested. A filtration series ends when 30 minutes or more elapse
between sample filtrations.
5.2.2 To prevent carry-over, the filtration funnels must be rinsed with two or three 20-30 mL portions of
water after each sample filtration.
5.2.3 Inoculated medium must be incubated at 35° ±0.5°C for 22-24 hours.
5.2.4 All samples resulting in confluent or TNTC (too numerous to count) growth must be invalidated unless
total coliforms are detected. If no total coliforms are detected, record as "confluent growth" or "TNTC" and
request an additional sample from the same sampling site. Confluent growth is defined as a continuous bacterial
growth covering the entire membrane filter without evidence of sheen colonies (total coliforms). TNTC is
defined as greater than 200 colonies on the membrane filter in the absence of detectable coliforms. Laboratories
must not invalidate samples when the membrane filter contains at least one sheen colony. (Before invalidation,
the laboratory may perform a verification test on the total coliform-negative culture, i.e., on confluent or TNTC
growth, and a fecal coliform/£. colt test. If the verification test is total coliform-positive, the sample must be
reported as total coliform-positive. If the test is total coliform-negative, the sample must be invalidated. A fecal
coliform/£. cofi-positive result is considered a total coliform-positive, fecal coliform/£.c0/j-positive sample, even
if the initial and/or verification total coliform test is negative.)
5.2.5 All sheen colonies (pick all sheen colonies up to a maximum of five) must be verified using either single
strength lactose broth (LB) or lauryl tryptose broth (LTB) and single strength brilliant green lactose bile broth
(BGLBB), or EPA-approved cytochrome oxidase and 6-galactosidase rapid test procedure. Individual colonies
can be transferred with a sterile needle or loop, or applicator stick. When picking individual colonies, different
morphological types of up to five red questionable sheen colonies and/or red non-sheen colonies per sample must
be verified to include different types. Alternatively, wipe the entire surface of the membrane filter with a sterile
cotton swab.
5.2.6 When EC Medium or EC Medium + MUG is used, the colonies must be transferred by employing one
of the options specified by paragraph 141.21(f)(5). For the swab technique, a single swab can be used to
inoculate a presumptive total coliform-positive culture into up to three different media (e.g., EC or EC-MUG
Medium, LTB, and BGLBB, in that order).
5.5 Multiple Tube Fermentation Technique (MTF or MPN) (for total coliforms in drinking water)
5.3.1 Various testing configurations can be used (CFR141.21(f)(3) , see Appendix G), as long as a total sample
volume of 100 mL is examined for each test.
5.3.2 Media
5.3.2.1 LTB (also known as lauryl sulfate broth) must be used in the presumptive test and BGLBB in
the confirmed test. LB may be used in lieu of LTB (40 CFR 141.21(f)(3)) if the laboratory conducts
at least 25 parallel tests between this medium and LTB using the waters normally tested and this
comparison demonstrates that the false-positive rate and false-negative rate for total coliforms, using
LB, is less than 10%. This comparison should be documented and the records retained. The pH must
be 6.8 ±0.2 for LTB, and 7.2 +0.2 for BGLBB.
5.3.2.2 The test medium concentration must be adjusted to compensate for the sample volume so that
the resulting medium after sample addition is single strength. If a single 100-mL sample volume is
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used, the inverted vial should be replaced with an acid indicator (bromcresol purple) to prevent
problems associated with gas bubbles in large inverted tubes. The media must be autoclaved at 121 °C
for 12-15 minutes.
5.3.2.3 Sterile medium in tubes must be examined to ensure that the inverted vials, if used, are free
of air bubbles and are at least one-half to two-thirds covered after the water sample is added.
5.3.2.4 If MTF media are refrigerated after sterilization, they should be incubated overnight at room
temperature before use. Tubes/bottles showing growth and/or bubbles should be discarded. If
prepared broth media are stored, they should be maintained in the dark at < 30 °C no longer than three
months for screw-cap tubes/bottles and two weeks for tubes/bottles with loose-fitting closures. Media
should be discarded if evaporation exceeds 10% of the original volume.
5.3.3 After the medium is inoculated, it must be incubated at 35° +0.5°C for 24 + two hours. If no gas or acid
is detected, it must be incubated for another 24 hours.
5.3.4 All samples that produce a turbid culture (i.e., heavy growth, opaque) in the absence of gas/acid
production, in LTD or LB, must be invalidated. The laboratory must collect, or request that the system collect,
another sample from the same location as the original invalidated sample. (Before invalidation, the laboratory
may perform a confirmed test on the total coliform-negative culture. If the confirmed test is total coliform-
positive, the sample must be reported as such. If the test is total coliform-negative, the sample must be
invalidated.)
5.3.5 24- and 48-hour gas-positive or acid-positive tubes must be confirmed using BGLBB.
5.3.6 A completed test is not required.
5.3.7 If the MTF test is used on water supplies that have a history of confluent growth or TNTC by the MF
procedure, all presumptive tubes with heavy growth without gas/acid production must be submitted to the
confirmed test and a fecal coliform/E. coli test to check for coliform suppression. (The Total Coliform Rule
requires that laboratories invalidate presumptive tubes with heavy growth without gas production and request
that the system provide another water sample within 24 hours. However, if the confirmed test is coliform-
positive, the laboratory may consider the first sample as coliform-positive. In contrast, if the confirmed test is
coliform-negative, the laboratory must not consider this sample as coliform-negative, because high levels of non-
coliform bacteria in the presumptive tubes may have injured, killed, or suppressed the growth of any coliforms
in the sample. A fecal coliform/E'. coli positive result is considered a total coliform-positive, fecal coliform/E.
co/i-positive sample, even if the presumptive and/or confirmed total coliform test is negative.)
5.4 Presence-Absence (P-A) Coliform Test (for drinking water)
5.4.1 Medium
5.4.1.1 Six-times formulation strength may be used if the medium is filter-sterilized rather than
autoclaved.
5.4.1.2 The medium must be autoclayed for 12 minutes at 121 °C. Total time in the autoclave should
be less than 30 minutes. Space should be allowed between bottles. The pH must be 6.8 ±0.2.
5.4.1.3 If prepared medium is stored, it should be maintained in a culture bottle at < 30°C in the dark
for no longer than three months. If evaporation exceeds 10% of original volume earlier, the medium
should be discarded.
5.4.2 A 100-mL sample must be inoculated into a P-A culture bottle.
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5.4.3 Medium must be incubated at 35° ±0.5°C and observed for a yellow color (acid) after 24 and 48 hours.
5.4.4 Yellow cultures must be confirmed in BGLBB and a fecal coIiform/51. coli test must be conducted.
5.4.5 All samples which produce a non-yellow turbid culture in P-A medium must be invalidated. The
laboratory must collect, or request that the system collect, another sample from the same location as the original
invalidated sample. (Before invalidation, the laboratory may perform a confirmed test on the total coliform
negative culture and/or a fecal coliform/^. coli test. If the confirmed test is total coliform-positive, the sample
must be reported as such. If the confirmed test is negative, the sample must be invalidated. A fecal coliform/E.
coli positive result is considered a total coliform-positive, fecal coliform/jE1. coli positive sample, even if the
presumptive and/or confirmed total coliform test is negative.)
5.5 Fecal Coliform Test (using EC Medium for fecal conforms in drinking water or source water, or A-l Medium
for fecal conforms in source water only)
5.5.1 EC medium must be used to determine whether a total coliform-positive culture taken from the distribution
system contains fecal coliforms, in accordance with the Total Coliform Rule. The laboratory must transfer each
total coliform-positive culture from a presumptive tube/bottle, or each presumptive total coliform-positive colony
(five such colonies minimum) unless a cotton swab is used, to at least one tube containing EC Medium with an
inverted vial, as specified by §141.21(f)(5).
5.5.2 EC Medium may be used to enumerate fecal coliforms in source water, in accordance with the Surface'
Water Treatment Rule. Initially, conduct an MTF test (presumptive phase). Three sample volumes of source
water (10, 1 and 0.1 mL), 5 or 10 tubes/sample volume, should be used. A culture from each total coliform-
positive tube must be transferred to a tube containing EC Medium with an inverted vial.
5.5.2.1 Medium must be autoclaved for 12^15 minutes at 121 °C. The pH must be 6.9 ±0.2.
5.5.2.2 Inverted vials should be examined to ensure that they are free of air bubbles. The inverted
vial must be at least one-half to two-thirds covered after the sample is added.
5.5.2.3 If prepared medium is stored, it should be maintained in the dark at <30°C. Prepared
medium stored in tubes with loose-fitting closures should be used within two weeks. Prepared medium
stored in tightly closed screw type tubes may be kept up to three months. If the medium is stored in
a refrigerator, it should be incubated overnight at room temperature before use; tubes that show growth
and/or bubbles should be discarded.
5.5.3 A-l Medium may be used as an alternative to EC Medium to enumerate fecal coliforms in source water,
in accordance with the Surface Water Treatment Rule. A-l Medium must not be used for drinking water
samples. Three sample volumes of source water (10, 1 and 0.1 mL), 5 or 10 tubes/sample volume, should be
used. Unlike EC Medium, A-l Medium can be directly inoculated with a water sample.
5.5.3.1 Medium must be sterilized by autoclaving at 121°C for 10 minutes. The pH must be 6.9
±0.1.
5.5.3.2 Inverted vials should be examined to ensure that they are free of air bubbles.
5.5.3.3 Loose-^cap tubes should be stored in dark at room temperature not more than two weeks. A-l
Medium may be held up to three months in a tightly closed screwcap tube in the dark at < 30°C.
5.5.4 The water level of the water bath must be above the upper level of the medium in the culture tubes.
5.5.5 EC Medium must be incubated at 44.5° ±0.2°C for 24 ±2 hours. A-l Medium must be incubated at
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35° ±0.5°C for three hours, then at 44.5° ±0.2°C for 21 ±2 hours.
5.5.6 Any amount of gas detected in the inverted vial of a tube that has turbid growth must be considered a fecal
coliform-positive test.
5.6 Chromogenic/fluorogenic substrate tests (MMO-MUG test [Colilert test] for total coliforms in source water
and total coltforms and E. coli in drinking water; Colisure test for total coliforms and E. cott in drinking
water)
5.6.1 Media
5.6.1.1 These media must not be prepared from basic ingredients, but rather purchased from a
commercially available source.
5.6.1.2 The media must be protected from light. Colisure medium must be refrigerated until use and
brought to room temperature before adding the sample.
5.6.1.3 Some lots of fluorogenic media have been known to autofluoresce. Therefore, each lot of
medium should be checked before use with a 366-nm ultraviolet light with a 6-watt bulb. If the media
exhibit faint fluorescence, the laboratory should use another lot that does not fluoresce. If the samples
plus a medium exhibit a color change before incubation, it should be discarded and another batch of
medium used.
QC 5.6.1.4 For each lot of medium, a quality control check must be performed by inoculating sterile water
containing the medium with a MUG-positive E. coli strain, a MUG-negative coliform, and a non-
coliform and analyzing them.
QC 5.6.1.5 Laboratories may also use Quanti-Tray test or Quanti-Tray 2000 test for drinking water and
source waters. Both tests use the Colilert medium. If the Quanti-Tray or Quanti-Tray 2000 test is
used, the sealer should be checked monthly by adding a dye (e.g., bromcresol purple) to the water.
If dye is observed outside the wells, another sealer should be obtained.
5.6.2 A glass bottle that contains inoculated medium should be checked with a 366-nm ultraviolet light source
with a 6-watt bulb. If fluorescence is observed before incubation, do not use.
5.6.3 For enumerating total coliforms in source water with the Colilert test, 5 or 10 tube MTF, Quanti-Tray
or Quanti-Tray 2000 must be used for each sample dilution tested. Dilution water (for the
chromogenic/fluorogenic substrate test only), if used, must be sterile dechlorinated tap water, deionized water,
or distilled water.
5.6.4 For determining the presence of total coliforms in drinking water by a cliromogenic/fluorogenic substrate
test, laboratories must use 10 tubes, each containing 10 niL of water sample, or a single vessel containing 100
mL of water sample.
5.6.5 For the Colilert test, samples must be incubated at 35 ±0.5°C for 24 hours. A yellow color in the
medium equal to or greater than the reference comparator indicates the presence of total coliforms and must be
reported as a total coliform positive. If the sample is yellow, but lighter than the comparator, it must be
incubated for another four hours (do not incubate more than 28 hours total). If the color is still lighter than the
reference comparator at 28 hours, the sample should be reported as negative. Laboratories that use the Colilert-
18 test must incubate for 18 hours.
5.6.6 For the Colisure test, samples must be incubated at 35 ±0.5°C for 28 hours. If an examination of the
results at 28 hours is not convenient, then results may be examined at any time between 28 and 48 hours. If the
medium changes from a yellow color to a magenta color, the sample must be reported as E. coli positive.
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5.6.7 For E. coti testing, the laboratory must place all total coliform-positive bottles/tubes under an ultraviolet
lamp (366 nm, 6-watt) in a darkened room. If E. coli is present, the medium will emit a blue fluorescence.
QC 5.6.8 Air-type incubators, especially small ones, may not bring a cold 100-mL water sample(s) to the specified
incubation temperature of 35°C for several hours. This problem may be further aggravated if several cold water
samples are placed in the incubator at the same time. The problem may cause false-negative results with the
chromogenic/fluorogenic substrate tests. Therefore, laboratories with air-type incubators should check the time
it takes for a 100-mL water sample (or a set of 100-mL water samples, depending on normal use)|to reach 35°C,
and ensure that the specified incubation period at that temperature is followed. This check should be repeated
whenever there is a significant change in the sample load.
5.6.9 The Colilert/Colisure tests must not be used to confirm total conforms on membrane filters. The filtration
step not only concentrates coliforms, but also non-coliforms and turbidity, which at high levels, can suppress
conforms or cause false-positive results in the chromogenic/fluorogenic substrate test.
5.6.10 The Colilert/Colisure tests must not be used to confirm total coliforms in the MTF or Presence-Absence
(P-A) coliform test. High densities of non-coliforms in the inoculum may overload the chromogenic/fluorogenic
substrate test suppressant reagent system and cause false positive results.
5.7 EC Medium + MUG Test (forE. coli)
5.7.1 ff EC medium + MUG is used, a total coliform-positive culture must be transferred from a presumptive
tube/bottle or colony to EC medium + MUG, as specified by §141.21(f)(5).
5.7.2 Medium
5.7.2.1 MUG may be added to EC Medium before autoclaving. EC Medium + MUG is also
available commercially. The final MUG concentration must be 50 /ug/mL. The pH must be 6.9 ±0.2.
5.7.2.2 The inverted vial may be omitted, because gas production is not relevant to the test, and the
use of an inverted vial may cause confusion on test interpretation.
5.7.2.3 Test tubes and autoclaved medium should be tested before use with a 366-nm ultraviolet light
to ensure they do not fluoresce. If fluorescence is exhibited, rion-fluorescing tubes or another lot of
medium that does not fluoresce should be used; alternatively, a MUG-positive E. coli and MUG-
negative (e.g., uninoculated) control should be performed for each analysis.
5.7.2.4 If prepared medium is stored, it should be maintained in the dark at <30°C. Prepared
medium stored in tubes with loose-fitting closures should be used within two weeks. Prepared medium
stored in tightly closed screw type tubes may be kept up to three months. Tubes with growth should
be discarded.
QC 5.7.2.5 In accordance with paragraph 5.1.7.5, control cultures should be incubated at 35° ±0.5°C
for 24 hours in LTB. A loopful should be transferred to EC Medium + MUG and then incubated at
44.5° ±0.2°C for 24 hours. The results should be read and recorded.
5.7,3 The water level of the water bath must be above the upper level of the medium.
5.7.4 The medium must be incubated at 44.5° +0.2°C for 24 ±2 hours.
5.7.5 Fluorescence must be checked using an ultraviolet lamp (366 nm) with a 6-watt bulb in a darkened'room.
Laboratories should ensure that a weak auto-fluorescence of medium, if present, is not misinterpreted as positive
for E. coli. (If uncertain, a MUG-positive E. coli and MUG negative (e.g., uninoculated) control for each
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analysis should be used whenever the medium autofluoresces.)
5.8 Nutrient Agar + MUG Test (for E. coli)
5.8.1 Medium
5.8.1.1 Medium must be autoclaved in 100-mL volumes at 121 °C for 15 minutes. MUG may be
added to Nutrient Agar before autoclaving. Nutrient Agar + MUG is also available commercially.
The final MUG concentration must be 100 yUg/mL. The pH must be 6.8 ±0.2.
5.8.1.2 If sterile medium is stored, the medium should be refrigerated in petri dishes, in a plastic bag
or tightly closed container, and used within two weeks. Before use, refrigerated sterilized medium
should be incubated overnight at room temperature; plates with growth should be discarded.
QC 5.8.1.3 Positive and negative controls should be tested as stated in paragraph 5.1.7.5. Filter or spot-
inoculate control cultures onto a membrane filter on M-Endo LES agar or M-Endo broth or agar, and
incubate at 35°C for 24 hours. Then transfer the filter to Nutrient Agar + MUG and incubate at 35°C
for another four hours. The results should be read and recorded.
5.8.2 The membrane filter containing coliform colony(ies) must be transferred from the total coliform medium
to the surface of Nutrient Agar + MUG medium. Each sheen colony should be marked with a permanent
marker on the lid. Also, the lid and the base should be marked with a line to realign the lid should it be
removed. A portion of the colony may be transferred with a needle to the total coliform verification test before
transfer to Nutrient Agar + MUG or after the four-hour incubation time. Another method is to swab the entire
membrane filter surface after the 4-hour incubation time onto the Nutrient Agar + MUG medium, with a sterile
cotton swab, and transfer to a total coliform verification test.
5.8.3 Inoculated medium must be incubated at 35° ±0.5C° for four hours.
5.8.4 Fluorescence must be checked using an ultraviolet lamp (366 nm) with a 6-watt bulb in a darkened room.
Any amount of fluorescence in a halo around a sheen colony should be considered positive for
E. coli.
5.9 Heterotrophic Plate Count (for enumerating heterotrophs in drinking water)
5.9.1 The Pour Plate Method must be used for enumerating heterotrophic bacteria in drinking water under
§141.74(a)(3), (also listed in Appendix G) and should be used for testing reagent grade water. For systems that
have been granted a variance from the Total Coliform Rule's maximum contaminant level (see variance criteria
in the preamble of FR 56:1556-1557, January 15, 1991), any method in Standard Methods section 9215,
"Heterotrophic Plate Count," may be used with R2A medium, for enumerating heterotropliic bacteria in drinking
water.
5.9.2 Media (includes plate count agar [tryptone glucose extract agar] and R2A agar)
5.9.2.1 Final pH values must be 7.0 ± 0.2 for plate count agar and 7.2 ± 0.2 for R2A agar.
5.9.2.2 (For Pour Plate Method) Melted agar must be tempered at 44-46°C in waterbath before
pouring. Melted agar should be held no longer than three hours. Sterile agar medium should not be
melted more than once.
5.9.2.3 (For Spread Plate Method) 15 mL of R2A agar medium (or other medium) should be poured
into a petri dish (100 x 15 mm or 90 x 15 mm) and allowed to solidify.
5.9.2.4 Refrigerated medium may be stored in bottles or in screw-capped tubes for up to six months,
or in petri dishes for up to two weeks. Prepared petri dishes with R2A medium may be stored for up
to one week.
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5.9.3 For most potable water samples, countable plates can be obtained by plating 1.0 mL and/or 0.1 mL
volumes of the undiluted sample. At least duplicate plates per dilution should be used.
5.9.4 (For Pour Plate Method) The sample must be aseptically pipetted onto the bottom of a 100 mm x 15 mm
petri dish (100 x 15 mm or 90 x 15 mm). Then, 12-15 mL of tempered melted (44-46°C) agar must be added
to each petri dish. The sample and melted agar must be mixed carefully to avoid spillage. After agar plates
have solidified on a level surface, the plates must be inverted and incubated at 35° + 0.5°C for 48+3 hours.
Plates should be stacked no more than four high and arranged in the incubator to allow proper air circulation
and to maintain uniform incubation temperature.
5.9.5 (For Spread Plate Method) 0.1 or 0.5 mL of the sample (or dilution) must be pipetted onto the surface
of the predried agar in the plate, and then spread over the entire surface of the agar using a sterile bent glass
rod. The inoculum must be absorbed completely by the agar before the plate is inverted and incubated. The
plate must be incubated at 20-28°C for 5-7 days.
5.9.6 (For Membrane Filter Technique) The volume to be filtered must yield between 20-200 colonies. The
filter is transferred to a petri dish containing 5 mL of solidified R2A medium, and incubated at 20-28 °C for 5-7
days. If plates with loose-fitting lids are used, plates must be placed in a plastic box with a close fitting lid
containing moistened paper towels. Paper towels should be rewetted as necessary to maintain moisture.
Colonies must be counted using a stereoscopic microscope at 10-15X amplification.
5.9.7 (For Pour Plate and Spread Plate Techniques) Colonies must be counted manually using a darkfield
colony counter. In determining sample count, laboratories must only count plates having 30 to 300 colonies,
except for plates inoculated with 1.0 mL of undiluted sample. Counts less than 30 for such plates are acceptable.
(Fully automatic colony counters are not suitable because of the size and small number of colonies observed
when potable water is analyzed for heterotrophic bacteria).
QC 5.9.8 Each batch or flask of agar should be checked for sterility by pouring a final control plate. Data should
be rejected if control is contaminated.
5.10 Membrane Filter Technique (for enumerating total coliforms in source water)
5.10.1 The same as paragraphs 5.2.1-5.2.4 except that in paragraph 5.2.4, laboratories must invalidate any
sample which results in confluent growth or TNTC, even when total coliform colonies are present and because
coliform density must be determined.
5.10.2 To optimize counting, appropriate sample dilutions must be used to yield 20 to 80 total coliform colonies
per membrane.
5.10.3 Initial counts must be adjusted based upon verified data, as in Standard Methods, Section 9222B.
QC , 5.10.4 If two or more analysts are available, each analyst should count the total coliform colonies on the same
membrane, monthly. Colony counts should agree within 10%.
5.17 Multiple Tube Fermentation Technique (for enumerating total coliforms in source water)
5.11.1 Laboratories must use at least 3 series of 5 tubes each with appropriate sample dilutions of source water
(e.g., 0.1 mL, 0.01 mL, 0.001 mL). •
5.11.2 Follow the instructions in paragraphs 5.3.1 - 5.3.6, except for 5.3.4 on sample invalidation.
5.11.3 All samples that produce a turbid culture (i.e., heavy growth, opaque) in the absence of gas/acid
production, in LTB or LB, must be invalidated. The laboratory must collect, or request that the system collect,
another sample from the same location as the original invalidated sample. The laboratory may use another
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method to test the second sample. Alternatively, if a sample produces a turbid culture in the absence of gas
production, a confirmed test may be performed. If the confirmed test is total coliform-positive, the MPN should
be reported. If a confirmed test is total colifbrm-negative, the sample must be invalidated and another one
requested.
5.12 Fecal Cotiform Membrane Filter Procedure (for enumerating fecal coliforms in source water)
5.12.1 Medium (m-FC broth/agar)
5.12.1.1 m-FC broth (with or without agar) must be prepared by bringing it just to the boiling point.
However, medium must not be autoclaved. Final pH must be 7.4 ±0.2.
5.12.1.2 When stored, prepared medium should be refrigerated. Broth medium must be discarded
after 96 hours and poured an agar medium in petri dishes should be discarded after two weeks.
Medium should be discarded earlier if growth is observed.
5.12.2 Appropriate sample volumes to yield 20-60 fecal coliform colonies per membrane for at least one dilution
must be used.
QC 5.12.3 To prevent carry-overs, the filtration funnels must be rinsed with two or three 20-30 mL portions of
sterile rinse water after each sample filtration.
QC 5.12.4 A sterility check should be conducted at the beginning and end of each filtration series by filtering 20-30
mL of dilution water through the membrane filter. If the control indicates contamination, all data from affected
samples should be rejected and immediate resampling requested.
5.12.5 Inoculated medium must be incubated at 44.5° ±0.2°C for 24 ±2 hours.
QC 5.12.6 If two or more analysts are available, each analyst should count fecal coliform colonies on the same
membrane monthly. Colony counts should agree within 10%.
6. Sample Collection, Handling, and Preservation
Paragraphs 6.1-6.5 are applicable to those laboratories that collect samples. However, all laboratories should make an
effort to ensure proper sample collection; all laboratories are responsible for paragraph 6.6.
6.1 Sample Collector
The sample collector should be trained in aseptic sampling procedures and, if required, approved by the appropriate
regulatory authority or its designated representative.
6.2 Sampling
(For drinking water) Samples must be representative of the water distribution system. Water taps used for sampling
should be free of aerators, strainers, hose attachments, mixing type faucets, and purification devices. Cold water taps
should be used. The service line must be cleared before sampling by maintaining a steady water flow for at least two
minutes (until the water changes temperature). At least 100 mL of sample must be collected, allowing at least a 1-inch
air space to facilitate mixing of the sample by shaking.. Immediately after collection, a sample information form should
be completed (see paragraph 6.5). See Section 3.15.4 regarding sample dechlorination.
Source water samples must be representative of the source of supply, collected not too far from the point of intake, but
at & reasonable distance from the bank or shore. The sample volume should be sufficient to perform all the tests required.
6.3 Sample Icing
Samplers are encouraged, but not required, to hold drinking water samples at < 10°C during transit to the laboratory.
Source water samples must be held at < 10°C (see Standard Methods, Section 9060B).
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6.4 Sample Holding/Travel Time
The time from sample collection to initiation of analysis for total boliforms, fecal coliforms, or E. coli in drinking water
must not exceed 30 hours. The time from sample collection to initiation of analysis for total coliforms and fecal coliforms
in source water, and heterotrophic bacteria in drinking water must not exceed eight hours (see Section 9060B in Standard
Methods). All samples received in the laboratory should be analyzed on the day of receipt. If the laboratory receives
the sample late in the day, the sample may be refrigerated overnight as long as analysis begins within 30 hours of sample
collection.
6.5 Sample Information Form
After collection, the sampler should enter on a sample information form, in indelible ink, the following information:
• Name of system (public water system site identification number, if available)
• Sample identification (if any)
• Sample site location
• Sample type (e.g., routine distribution system sample, repeat sample, raw or process water| other special purpose
sample)
• Date and time of collection
• Analysis required .
• Disinfectant residual
• Name of sampler and organization (if not the water system)
• Sampler's initials
• Person(s) transporting the samples from the system to the laboratory (if not the sampler)
• Transportation condition (e.g., < 10°C, protection from sunlight). If a commercial shipper was used, shipping records
should be available.
• Any remarks
6.6 Chain-of-Custody
Sample collectors and laboratories must follow applicable State regulations pertaining to chain-of-custody. An example
of such a plan is provided in Appendix A.
7. Quality Assurance
A written QA plan should be prepared and followed (see Chapter IS). The QA plan should be available for inspection
by the certification officer.
8. Records and Data Reporting
8.1 Legal Defensibility: Compliance monitoring data should be made legally defensible by keeping thorough and
accurate records. The QA plan and/or SOPs should describe the policies and procedures used by the facility for record
retention and storage. If samples are expected to become part of a legal action, chain-of-custody procedures should be
used ( See Appendix A).
8.2 Maintenance of Records: Public Water Systems are required to maintain records of microbiological analyses
of compliance samples for five years (40 CFR 141.33). The laboratory should maintain easily accessible records for five
years or until the next certification data audit is complete, whichever is longer. The client water system should be notified
before disposing of records so they may request copies if needed. This includes all raw data, calculations, and quality
control data. These data files may be either hard copy, microfiche or electronic. Electronic data should always be backed
up by protected tape or disk or hard copy. If the laboratory changes its computer hardware or software, it should make
provisions for transferring old data to the new system so that it remains retrievable within the tune frames specified above.
Data which is expected to become part of a legal action will probably need to be maintained for a longer period of time.
Check with your legal counsel. See Appendix H, section 3.0, and Good Automated Laboratory Practices, EPA 2185,
Office of Information Management, Research Triangle Park, NC 27711, 8/10/95.
8.3 Sampling Records: Data should be recorded in ink with any changes lined through such that original entry is
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visible. Changes should be initialed and dated The following information should be readily available in a summary or
other record(s): ;
8.3.1 Sample information form, from 6.5 above;
8.3.2 Date and time of sample receipt by the laboratory; name of carrier
8.3.3 Name of laboratory person receiving the sample;
8.3.4 If a deficiency in the condition of the sample is noted, the sample, at a minimum,
is flagged;
8.3.5 If sample transit time exceeds 30 hours (8 hours for source water samples), sample
must be tagged;
8.4 Analytical Records: Data should be recorded in ink with any changes lined through such that original entry
is visible. Changes should be initialed and dated The following information should be readily available in a summary
or other record(s):
8.4.1 Laboratory sample identification;
8.4.2 Date and time analysis begins;
8.4.3 Laboratory and person(s) responsible for performing analysis;
8.4.4 Analytical technique or method used;
8.4.5 All items marked QC;
8.4.6 Results of analyses.
8.5 Preventive Maintenance
Laboratories should maintain preventive maintenance and repair activities records for all instruments and equipment
(including pH meters, analytical balances, incubators, refrigerators, autoclaves and water baths). Records should be kept
for five years.
9. Action Response to Laboratory Results
9.1 Testing Total Coliform-Positive Cultures
For the Total Conform Rule, laboratories must test all total colifonn-positive cultures for the presence of either fecal
coliforms or E. coli.
9.2 Notification of Positive Results
For the Total Coliform Rule, laboratories must promptly notify the proper authority of a positive total colifonn, fecal
colifonn, or E. coli result, so that appropriate follow-up actions (e.g., collection of repeat samples) can be conducted (see
CFR 141.21(b) and (e), 40 CFR 141.31, etc.) A total colifonn-positive result is based on a confirmed phase for the
Multiple Tube Fermentation Technique and Presence-Absence (P-A) Coliform Test, or verified test for Membrane Filter
Technique. No requirement exists for confirmation of positive Colilert/Colisure tests, fecal coliform test, or E. coli tests.
In those rare cases where a presumptive total coliform-positive culture does not confirm/verify as such, but is found to
be fecal coliform or E. coli positive, the sample is considered total coliform-positive and fecal coliform/£. coli positive.
9.3 Invalidation of Total Coliform-Negative Sample
For the Total Coliform Rule, the laboratory must promptly notify the proper authority (usually the water system) when
results indicate that non-coliforms may have interfered with the total colifonn analysis, as described in 40 CFR
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MICROBIOLOGY LABORATORY ANALYSIS REVIEW CHECKLIST
LABORATORY_
ADDRESS
TELEPHONE NUMBER/FAX NUMBER
CONDUCTED BY_
DATE
NAMES/TITLES/RESPONSIBILITIES OF KEY PERSONNEL INTERVIEWED
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Element
I. PERSONNEL
1.1 Supervisor/Consultant
Supervisor of analyst has a bachelor's degree in microbiology,
biology, or equivalent with at least one college-level laboratory
course in environmental microbiology, and has a minimum of two
weeks course training or 80 hours of on-the-job training in water
microbiology at a certified laboratory, or other training acceptable to
the State or EPA
If supervisor not available, consultant with same training and
experience substituted, acceptable to the State, and present on-site
frequently enough to satisfactorily perform a supervisor's duties
1.2 Analyst (or equivalent job title)
Analyst has a high school education, 3 months bench experience in
microbiology, training in microbiological analysis of drinking water
acceptable to the State (or EPA) and a minimum of 30 days on-the-
job training under an experienced analyst
Analyst demonstrated acceptable results for precision, specificity,
and satisfactory analysis on unknown samples before analyzing
compliance samples
1.3 Waiver of Academic Training Requirement
Need for specified academic training waived for highly experienced
analysts
1.4 Personnel Records
Personnel records maintained on laboratory analysts include
academic background, specialized training courses completed and
types of microbiological analyses conducted
2. LABORATORY FACILmES
Laboratory facilities clean, temperature and humidify controlled,
with adequate lighting at bench top
Sufficient space available for processing samples, bench top
equipment, storage, cleaning glassware and sterilizing materials
Provisions made for disposal of microbiological wastes
5. LABORATORY IQtfflPMElW A1«) SOPPLffllS
3.1 pH meter
Accuracy and scale graduations within ± 0. 1 units
Buffer aliquot used only once
Yes
No
_
Comments
f
-
V-20
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Element
Electrodes maintained according to manufacturer's recommendations
QC Meter standardized each use period with pH 7.0 and either 4.0
or 10.0 buffers, with date and buffers used recorded in log book
QC Commercial buffer solutions dated when received and opened
and discarded before expiration date
3.2. Balance (top loader or pan)
Readability of 0.1 g
QC Calibrated monthly using ASTM type 1, 2, or 3 weights
(minimum 3 traceable weights which bracket laboratory weighing
needs)
QC Non-reference weights calibrated every six months with
reference weights
QC Annual service contract or internal maintenance protocol
established, records available of most recent recalibration, and
correction values on file and used
QC Reference weight recertified if damaged or corroded
3.3 Temperature Monitoring Device
Temperature monitoring devices graduated in 0.5 °C increments
(0.2°C increments for tests which are incubated at 44.5°C) or less
No separation in fluid column of glass thermometer
No dial thermometers used which cannot be adjusted
QC Glass and electronic thermometers calibrated annually, dial
thermometers quarterly, at the temperature used against reference
NIST thermometer or one meeting the requirements of NBS
Monograph SP 250-23
QC Calibration factor marked on thermometer and calibration date
and calibration factor recorded in QC record book
QC Thermometer discarded if off more than 1°C from reference
thermometer, reference thermometers recalibrated every 3-5 years
QC Continuous recording devices used to monitor incubator
temperature recalibrated annually as above
3.4 Incubator Unit
Incubator units have an internal temperature monitoring device and
maintain temperature of 35 ± 0.5°C, and if used, 44.5 ± 0.2°C
Yes
No
Comments
V-21
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Element
Thermometers placed on top and bottom shelves of use area in non-
portable incubators, with thermometer bulb immersed in liquid
(except for electronic thermometers)
For aluminum block incubator, culture dishes and tubes fit snugly
QC Calibration-corrected temperature recorded twice daily for
days in use, readings separated by at least four houn;
Water bath equipped with gable cover and pump or paddles used to
circulate water (recommended for maintaining 44 + 0.2°C)
3.5 Autoclave
Autoclave has internal heat source, temperature gauge with sensor
on exhaust, pressure gauge, and operational safety valve
Maintains sterilization temperature during cycle and completes entire
cycle within 45 minutes when 12-15 minute sterilization period used
Depressurizes slowly enough to ensure media will not boil over and
bubbles will not form in inverted tubes
Pressure cookers not used
QC Date, contents, sterilization time, temperature, total cycle
time, and analyst's initials recorded for each cycle
QC Copy of service contract or internal maintenance protocol and
maintenance records kept
QC Maintenance conducted annually at a minimum, with record of
most recent service performed available for inspection
QC Maximum-temperature-registering thermometer or continuous
recording device used each autoclave cycle and temperature
recorded
QC Overcrowding avoided '
QC Spore strips or ampules used monthly
QC Automatic timing mechanism checked quarterly with
stopwatch or other accurate timepiece or time signal
Autoclave door seals clean and free of caramelized media
Autoclave drain screen cleaned frequently
3.6 Hot Air Oven
Maintains stable sterilization temperature of 170-180°C for at least 2
hours
Only dry items sterilized in hot air oven
Yes
No
Comments
V-22
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Element
Overcrowding avoided
Oven thermometer graduated in 10°C increments or less, with bulb
placed in sand during use
QC Date, contents, sterilization time, temperature, and analyst's
initials recorded for each cycle
QC Spore strip or ampule used monthly
3.7 Colony Counter
Colony counter, dark field modelrused to count Heterotrophic Plate
Count colonies
3.8 Conductivity Meter
Suitable for checking laboratory reagent-grade water, readable in
micromhos/cm or microsiemens/cm with measurement error not
exceeding 1% or 1 micromhos/cm, whichever is more lenient
QC Cell constant determined monthly
In-line unit which cannot be calibrated not used to check reagent-
grade water
3.9 Refrigerator
Maintains 1-5 °C
Thermometer graduated in 1 °C increments or less, with
thermometer bulb immersed in liquid
QC Temperature recorded for days in use at least once per day
3.10 Inoculating Equipment
Sterile metal or disposable plastic loops, wood applicator sticks,
sterile swabs, or sterile plastic disposable pipet tips used
Wood applicator sticks sterilized byjlry heat
Metal inoculating loops and needles made of nickel alloy or platinum
(nickel alloy loops not used for oxidase test)
3.11 Membrane Filtration (MF) Equipment
MF units of stainless steel, glass, or autoclavable plastic, not
scratched or corroded and do not leak
QC Graduations on funnels used to measure sample volume
checked for accuracy have tolerance of ^2.5%, and a record of this
calibration check retained
Yes
No
Comments
. ' ? •
V-23
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Element
lOx to 15x stereo microscope with fluorescent light source used to
count sheen colonies
Membrane filters approved by manufacturer for uses in total coliform
analysis of water
Membrane filters of cellulose ester, white, gridmarked, 47 mm
diameter, and 0.45 /un pore size
Membrane filters and pads purchased presterilized or autoclaved
before use
Lot number and date received recorded for membrane filters
3.12 Culture Dishes (loose or tight lids)
Presterilized plastic or sterilizable glass culture dishes used
Sterility of glass culture dishes maintained by placement in stainless
steel or aluminum canisters or wrapped in heavy aluminum foil or
char-resistant paper
Loose-lid dishes incubated in tight-fitting container with moistened
paper towel
Opened packs of disposable culture dishes reseated between use
periods
3.13 Pipets
Glass pipets sterilized and maintained in stainless steel or aluminum
canisters or wrapped individually in char-resistant paper or
aluminum foil
Pipets with legible markings, not chipped or etched.
Opened packs of disposable sterile pipets resealed between use
periods
Pipets delivering volumes of 10 mL or less accurate within 2.5%
tolerance
Micropipetters used with sterile tips,calibrated annually, and
replaced if tolerance greater than 2.5 %
3.14 Culture Tubes and Closures
Tubes of borosilicate glass or other corrosion-resistant glass or
plastic
Culture tubes and containers of sufficient size to contain medium
plus sample without being more than three quarters full
Tube closures used of stainless steel, plastic, aluminum, or screw
caps with non-toxic liner; cotton plugs not used
Yes
No
Comments
•
V-24
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Element
3.15 Sample Containers
Wide-mouth plastic or non-corrosive glass bottles, with non-leaking
ground glass stoppers or caps with non-toxic liners, or sterile plastic
bags containing sodium thiosulfate used
Sample container capacity at least 120 mL (4 oz)
Glass stoppers covered with aluminum foil or char-resistant paper
for sterilization
Sample containers sterilized by autoclaving or (for glass bottles) dry
heat
Containers moistened with several drops of water before autoclaving
to prevent "air lock" sterilization failure ......-,„.,,.. ...
Sufficient sodium thiosulfate added to sample containers before
sterilization, if laboratory analyzes chlorinated water -
3.16 Glassware and Plasticware
Glassware made of borosilicate glass or other corrosion-resistant
glass, free of chips and cracks, with markings legible
Plastic items clear and non-toxic to microorganisms
QG Graduated cylinders and pre-calibrated containers used to
measure samples volumes accurate with a tolerance of 2.5% or less
QC New lots of pre-calibrated containers validated to have 2.5%
tolerance
3.17 Ultraviolet Lamp (if used)
Unit cleaned monthly by wiping with soft cloth moistened with
ethanol
QC If used for sanitization, tested quarterly with UV light meter or
by agar spread plate method (other methods acceptable if data
demonstrates they are as effective)
Yes
No
Comments
.. - . .. . ~ ... -. ., , ,
- .., ... ,"
••---• - •• -
."•••• '
.,,... .... .. -. , ......
4, «ENI»ALLABOIlATOEYt^CtICES
Laboratory facilities clean, temperature and humidify controlled, and
adequate lighting
4.1 Sterilization Procedures
V-25
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Element
Only analytical methodology specified in Total Colifbrm Rule and
Surface Water Treatment Rule used for compliance samples
Laboratory certified for all analytical methods it uses for compliance
purposes
Laboratory certified for at least one total conform method and one
fecal colifonn or E. coli method
Laboratory certified for a second total coliform method, if one
method cannot be used for some drinking waters
Laboratory that enumerates heterotrophic bacteria (i.e., HPC) for
compliance with the Surface Water Treatment Rule certified for the
Pour Plate Method
Absorbent pads, when used, saturated with liquid medium and
excess removed
Water sample shaken vigorously (about 25 times) before analysis
QC If no total coliform-positive results occur during a quarter,
laboratory performs coliform procedure using a known coliform-
positive, fecal conform- and/or E. co&'-positive control to spike the
sample
Sample volume analyzed for total conforms in drinking water is
100 ±2.5 mL
Media
Dehydrated or prepared media manufactured commercially used
(strongly recommended)
Dehydrated media stored in cool dry location and caked or
discolored dehydrated media discarded
QC Laboratory media preparation records include: .„,....
- date of preparation
- type of medium
- lot number
- sterilization time and temperature "
- final pH
- technician's initials.
QC For liquid media prepared commercially, the following are
recorded:
- date received
- type of medium
- lot number
- pH verification
Yes
No
Comments
V-28
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Element
QC Liquid media prepared commercially discarded by
manufacturer's expiration date ;.
QC Each new lot of dehydrated and prepared commercial medium
checked before use with positive and negative culture controls and
results recorded
QC Each new batch of laboratory-prepared medium checked
before use with positive and negative culture controls and results
recorded
Prepared plates refrigerated in sealed plastic bags or containers
not longer than two weeks, with bag or container dated with
preparation or expiration date
Loose-cap tubes of broth stored at < 30 °C no longer than two
weeks, tightly capped tubes no longer than 3 months at < 30°C
Refrigerated medium incubated at room temperature overnight
before use and discarded if growth observed
QC Parallel testing performed between a newly approved test
procedure and another EPA-approved procedure for several months
and/or several seasons (recommended)
5.2 Membrane Filter (MF) Technique (for total conforms in
drinking water)
Media
M-Endo broth or agar or LES Endo agar in single step or
enrichment technique used
Ethanol not denatured
Medium prepared in sterile flask and dissolved using boiling
water bath or hot plate with stir bar
Medium not boiled
LES Endo agar medium pH 7.2 ±0.2
M-Endo medium pH 7.2 ± 0.1
MF broth refrigerated no longer than 96 hours, poured MF agar
plates no longer than 2 weeks, ampuled M-Endo broth as per
manufacturer's expiration date
Uninoculated media discarded if growth or surface sheen
observed
QC Sterility check conducted on each funnel in use at beginning
and end of each filtration series (filtration series ends when 30
minutes or more elapse between sample filtrations)
Yes
No
Comments
V-29
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Element
QC If sterility control indifcates contamination, all data rejected and
another sample requested
Funnels rinsed with two or three 20-30 mL portions of sterile rinse
water after each sample filtration to prevent carry-over
Inoculated medium incubated at 35° ± 0.5°C for 22-24 hours
Samples resulting in confluent or too numerous to count (TNTC)
growth invalidated unless total colifonns detected (if laboratory
performs verification test before invalidation and test is total
colifonn-positive, sample is reported as such, but if test is total
coliform-negative, sample is invalidated)
Sample not invalidated if membrane filter contains at least one sheen
colony
All sheen colonies verified (up to a maximum of five) using either
single strength (LB) or (LTD) and single strength (BGLBB) or an
EPA-approved cytochrome oxidase and beta-galactosidase rapid test
procedure
When picking individual colonies, up to five red questionable sheen
colonies and/or red non-sheen colonies verified to include different
types or entire MF surface is swabbed
When EC medium or EC medium + MUG used, colonies
transferred by employing one option specified by 141.21 (f)(5)
Swab used to transfer presumptive total colifonn-positive culture can
inoculate up to three different media (e.g., EC medium, LTB, and
BGLBB in that order)
5.3 Multiple Tube Fermentation Technique (MTF or MPN) (for
total coliforms in drinking water)
Total sample volume of 100 mL examined by test configuration
found in 141.21 (f)(3) or Appendix G
Media
LTB used in presumptive test and BGLBB in confirmed test
LB used if system conducts at least 25 parallel tests between this
medium and LTB and demonstrates false-positive rate and false-
negative rate for total coliforms of less than 10%, with
comparison documented and records retained
LTB pH 6.8 ± 0.2
BGLBB pH 7.2 ±0.2
Test medium concentration adjusted to compensate for sample
volume so resulting medium single strength after sample addition
Yes
No
Comments
- - ••- -
- . . . ' . «...
V-30
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Element
If single 100 mL sample volume used, inverted vial replaced with
acid indicator
Medium autoclaved at 121 °C for 12-15 minutes
Inverted vials in sterile medium free of bubbles and at least one-
half to two-thirds covered after water sample added
Refrigerated sterile MTF media incubated overnight at room
temperature before use, with tubes/bottles showing growth and/or
bubbles discarded
Prepared broth media stored in dark at < 30°C for no longer than
3 months in screw-cap tubes/bottles, two weeks for those with
loose-fitting closures
Media discarded if evaporation exceeds 10% of original volume
Inoculated medium incubated at 35 °C ± 0.5 °C for 24 + 2 hours
If no gas or acid detected, inoculated medium incubated for another
24 hours
All samples showing turbid culture (i.e., heavy growth, opaque) in
the absence of gas/acid production invalidated and another sample
collected from the same location (if laboratory performs confirmed
test on turbid culture and confirmed test is total colifonn-positive,
sample reported as such, but if total coliform-negative, sample is
invalidated)
All 24- and 48-hour gas-positive or acid-positive tubes confirmed
using BGLBB
Completed Test not f eqiiired
When MTF test used on water supplies that have a history of
confluent growth or TNTC by the MF procedure, all presumptive
tubes with heavy growth without gas/acid production submitted to
confirmed test and fecal coliform/E. coli test to check for coliform
suppression . ..,...,..
5.4 Presence-Absence (P-A) Coliform Test (for drinking water)
Medium
When six-times formulation strength medium used, medium
filter-sterilized, not autoclaved
Medium autoclaved for 12 minutes at 121 °C with total time in
autoclave less than 30 minutes and with space between bottles
Medium pH 6.8 ± 0.2
Yes
•
No
Comments
V-31
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Element
Prepared medium stored in the dark at < 30°C for no longer than
3 months
Stored medium discarded if evaporation exceeds 10% of original
volume
100 ruL sample inoculated into P-A culture bottle
Medium incubated at 35° ± 0.5 °C and observed for yellow color
(acid) after 24 and 48 hours
Yellow cultures confirmed in BGLBB and fecal co\ifonn/E. coli test
conducted
Non-yellow turbid culture in P-A medium invalidated and another
sample obtained from the same location (if confirmed test performed
and sample is total coliform-positive, sample is reported as such, but
if confirmed test is negative, sample invalidated)
5.5 Fecal Coliform Test (using EC Medium for fecal coliforms
in drinking or source water, or A-l Medium for fecal coliforms
in source water only)
EC medium used to determine whether total coliform-positive
culture taken from distribution system contains fecal conforms, in
accordance with Total Coliform Rule
EC medium used to enumerate fecal coliforms in source water, in
accordance with Surface Water Treatment Rule, using cultures
transferred from each total coliform-positive tube
Three sample volumes (10, 1, and 0.1 ml) and 5 or 10 tubes/sample
volume used
Autoclaved at 121 °C for 12-15 minutes
Medium pH 6.9 ± 0.2
Inverted vials free of bubbles and at least one-half to two-thirds
covered after sample added
Tubes with loose-fitting closures used within two weeks, tightly
closed screw-cap tubes no longer than 3 months when held in the
darkat<30°C
Refrigerated medium incubated at room temperature overnight
before use and tubes with growth or bubbles in vials discarded
Alternatively, A-l Medium used to enumerate fecal coliforms in
source water, in accordance with Surface Water Treatment Rule
A-l medium not used for drinking water samples
•Yes
No
Comments
V-32
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Element
Three sample volumes of source water (10, 1, and 0.1 mL) and 5 or
10 tubes/sample volume used
Autoclaved at 121 °C for 10 minutes
Medium pH 6.9 ±0.1
Inverted vials free of air bubbles and at least one-half to two-
thirds covered after water sample added
Loose-cap tubes stored in dark at room temperature no longer
than 2 weeks, tightly closed screw-cap tubes no longer than 3
months when held in the dark at <30°C
Water level in water bath above upper level of medium in culture
tubes
EC Medium incubated at 44.5°C ± 0.2°C for 24 ± 2 hours
A-l Medium incubated at 35°C ± 0.5°C for 3 hours, then at
44.5°C ± 0.2°C for 21 ± 2 hours
Any gas detected in inverted vial considered fecal coliform positive
5.6 Chromogenic/Fluorogenic Substrate Tests (MMO-MUG Test
[Colilert] for total coliforms in source water and total conforms
and E. coll in drinking water; Colisure Test for total coliforms
and E. coU in drinking water)
Media
Purchased from commercially available source only
Media protected from light
Colisure medium refrigerated until use, brought to room
temperature before adding sample
Each lot of medium checked for autofluoresence before use with
366-nm ultraviolet light with 6 watt bulb
Medium which exhibits faint fluorescence discarded and another
lot used
Medium plus sample which exhibits color change before
incubation discarded and another batch of medium used
QC Each lot of medium checked by inoculating sterile water
containing the medium with a MUG-positive E. coli strain, a
MUG-negative coliform, and a non-coliform and analyzing them
If Quanti-Tray or Quanti-Tray 2000 test used with Colilert
medium, sealer checked monthly to determine leakage
Yes
No
Comments
V-33
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Element
Glass bottles that contain inoculated medium checked with 366-nm
ultraviolet light source with 6 watt bulb and discarded if
fluorescence observed before incubation
For enumeration of total coliforms in source water with Colilert
Test, 5 or 10 tube MTF, Quanti-Tray, or Quanti-Tray 2000 used for
each sample dilution tested
For chromogenic/fluorogenic substrate test only, sterile
dechlorinated tap water, deionized water, or distilled water used as
dilution water
For determining presence of total coliforms in drinking water by
chromogenic/fluorogenic substrate test, 10 tubes each containing 10
mL water sample or single vessel containing 100 ml, sample used
For Colilert Test:
Sample incubated at 35° ± 0.5° for 24 hours (for Colilert-18
test, sample incubated 18 hours)
Yellow color in medium equal to or greater than reference
comparator indicates total coliform presence
Medium with yellow color lighter than comparator and incubated
for another 4 hours (28 hours total)
Yellow color in medium lighter than comparator incubated for 28
hours recorded as negative
For Colisure Test:
Sample incubated at 35° ± 0.5°C for 28 to 48 hours
Total coliform positive sample indicates color change from
yellow to magenta
For E. coll determination, UV lamp (366-nm, 6-watt) shone on
total coliform-positive bottles/tubes in darkened room with blue
fluorescence indicating E. coli presence
QC Air-type incubators tested to determine time necessary for cold
100 mL water sample (or set of 100 mL water samples) to reach
incubation temperature of 35°C, ensuring specified incubation time
at that temperature is followed
Colilert/Colisure Test not used to confirm total coliforms on
membrane filters
Colilert/Colisure Test not used to confirm total coliforms in MTF or
P-A tests
5.7 EC Medium + MUG (for E. colt)
Yes
No
Comments
V-34
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Element
Total coliform-positive culture transferred to EC medium + MUG
Medium
MUG added to EC medium before autoclaving or commercially
available EC + MUG used
Final MUG concentration 50 ^g/mL
Medium pH 6.9 ±0.2
Inverted vial omitted (optional)
Test tubes and autoclaved medium checked for autofluorescence
before use with 366-nm UV light
If fluorescence exhibited, non-fluorescing tubes or another lot of
medium that does not fluoresce used or MUG-positive (E. coli)
and a MUG-negative (e.g. uninoculated) control included for
each analysis
Prepared medium in tubes with loose-fitting closures used within
two weeks, or three months for tightly closed screw-cap tubes
when held in the dark at < 30 °C
Uninoculated medium with growth discarded
QC Each lot of commercially prepared medium and each batch
of laboratory-prepared medium checked by inoculating LTB with
positive and negative culture controls, incubating at 35°C ±
0.5°C for 24 hours and then transferring to EC Medium + MUG
for further incubation at 44.5°C ± 0.2°C for 24 hours, with
results read and recorded
Water level of water bath above upper level of medium
Incubated at 44.5° ± 0.2°C for 24 ± 2 hours
Fluorescence checked using UV lamp (366-nm) with 6 watt bulb in a
darkened room
5.8 Nutrient Agar + MUG Test (for E. coll)
Medium
Medium autoclaved in 100 mL volumes at 121 °C for 15 minutes
MUG added to Nutrient Agar before autoclaving or Nutrient
Agar + MUG purchased commercially
Final MUG concentration 100 /tg/L
Medium pH 6.8 ± 0.2
Yes
No
Comments
V-35
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Element
Medium in petri dishes stored refrigerated in plastic bag or
tightly closed container and used within two weeks
Refrigerated sterilized medium incubated at room temperature
overnight and plates with growth discarded
QC Quality of medium lot/batch evaluated by filtering or spot-
inoculating positive and negative control cultures onto membrane
filter on M-Endo medium, incubating at 35°C for 24 hours, then
transferring filter to NA + MUG and further incubating at 35°C for
4 hours, with results read and recorded
Filter containing total coliform colony(ies) transferred to surface of
Nutrient Agar + MUG medium
Before incubation, presence of each sheen colony marked on petri
dish lid with permanent marker, and lid and base marked to realign
lid when removed
For total colifonn verification test, portion of colony transferred
with needle before or after NA + MUG incubation
Alternatively, membrane filter surface swabbed with sterile cotton
swab after 4 hour incubation and transferred to total coliform
verification test
Inoculated medium incubated at 35 ± 0.5°C for 4 hours
Fluorescence checked using UV lamp (366 nm) with 6 watt bulb in a
darkened room, with any fluorescence in halo around sheen colony
considered positive for E. coli
5.9 Heterotrophic Plate Count for enumerating heterotrophs in
drinking water
Pour Plate Method used for enumerating heterotrophic bacteria in
drinking water and for testing reagent grade water
For systems granted a variance from Total Coliform Rule's
maximum contaminant level, any method in Standard Methods used
with R2A medium for enumerating heterotrophic bacteria in
drinking water
Media (plate count agar [tryptone glucose extract agar] and R2A
agar)
Plate count agar pH 7.0 ± 0.2
R2A agar pH 7.2 ±0.2
(For Pour Plate Method) melted agar tempered at 44-46 °C in
waterbath before pouring, held no longer than 3 hours, and
melted only once
Yes
No
Comments
V-36
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Element
(For Spread Plate Method) 15 mL of R2A medium or other
medium poured into petri dish and solidified
Refrigerated medium in bottles or screw-capped tubes stored for
up to 6 months, petri dishes with medium for up to 2 weeks (one
week for R2A prepared petri dishes)
Countable plates obtained for most potable waters by plating 1.0 mL
and/or 0. 1 mL volume of undiluted sample
At least duplicate plates per dilution used
(For Pour Plate Method)
Sample pipetted aseptically into bottom of petri dish and then 12-
15 mL tempered melted agar added
Sample mixed with spillage avoided
After solidification on level surface, plates inverted and incubated
at 35°C ± 0.5°C for 48 ± 3 hours
Plates stacked no more than four high
(For Spread Plate Method)
0. 1 or 0.5 mL of sample or dilution pipetted onto surface of pre-
dried agar plate and inoculum spread over entire agar surface
using sterile bent .glass rod
Inoculum absorbed completely before plates inverted and
incubated at 20-28 °C for 5-7 days
(For Membrane Filter Technique)
Volume filtered to yield between 20-200 colonies
Filter transferred to petri dish containing 5 mL solidified R2A
medium and incubated at 20-28 °C for 5-7 days
Petri dishes with loose-fitting lids placed in container with close
fitting lid and moistened paper towels
Colonies counted using stereoscopic microscope at 10-15X
magnification
(For Pour Plate and Spread Plate Techniques)
Colonies counted manually using dark field colony counter
Only plates with 30 to 300 colonies counted, except for plates
inoculated with 1.0 mL of undiluted sample
Fully automatic colony counters not used
Yes
No
Comments
V-37
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Element
QC Medium sterility verified by pouring final control plate and
data rejected if control contaminated
5.10 Membrane Filter Technique (for enumerating total
coliforms in source water)
Same as Section 5.2, Membrane Filter Technique (for total
'coliforms in drinking water), except invalidation does not apply
Appropriate sample dilutions used to yield 20 to 80 total coliform
colonies per membrane
Initial counts adjusted based upon verified data
QC If two or more analysts available, each counts total coliform
colonies on same membrane monthly and agree within 10%
5.11 Multiple Tube Fermentation Technique (for enumerating
total coliforms in source water)
At least three series of 5 tubes each with appropriate sample
dilutions of source water used
Same as Section 5.3, Multiple Tube Fermentation Technique (for
total coliforms in drinking water) except on sample invalidation
All samples invalidated which produce turbid growth in the absence
of gas/acid production in LTB or LB and another sample obtained,
which may be tested using another method
Alternatively, confirmed test performed on turbid culture in the
absence of gas/acid production and, if total coliform-positive, most
probable number reported, or if total coliform-negative, sample
invalidated and another requested
5.12 Fecal Coliform Membrane Filter Procedure (for
enumerating fecal coliforms in source water)
Medium
m-FC broth (with or without agar) sterilized by bringing to
boiling point, not autoclaved
Medium final pH 7.4 ± 0.2
Prepared medium refrigerated and broth discarded after 96 hours,
poured agar medium in petri dishes after 2 weeks
Uninoculated medium discarded if growth observed
Sample volumes yield 20-60 fecal coliform colonies per membrane
for at least one dilution
Yes
No
Comments
.'.
V-38
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Element
QC Funnels rinsed with two or three 20-30 mL portions of sterile
rinse water after each sample filtration to prevent carry-over
QC Sterility checked at beginning and end of each filtration series
and all data rejected from affected samples and resampling requested
if controls contaminated
Inoculated medium incubated at 44.5°C ± 0.2°C for 24 ± 2 hours
QC If two or more analysts available, each counts fecal conform
colonies on same membrane monthly and counts agree within 10%
& S AS1PEE COLLECTION, HA1WIMG, AND1JRESERVATI
6.1 Sample Collector
Trained in aseptic sampling procedures and, if required, approved
by appropriate regulatory authority or designated representative
6.2 Sampling
Sample representative of water distribution system
Water taps used for sampling free of aerators, strainers, hose
attachments, mixing type faucets, and purification devices
Cold water tap used
Service line cleared before sampling by maintaining steady water
flow for at least 2 minutes
At least 100 mL sample volume collected, allowing one inch air
space in container
Sample information form completed immediately after sample
collection
Source water representative of supply, collected not too far intake at
a reasonable distance from shore
6.3 Sample Icing
Samples held at < 10°C during transit to laboratory
(recommended for drinking water, required for source water)
6.4 Sample Holding/Travel Time
Time from sample collection to initiation of analysis for total
conforms, fecal coliforms, or E. coli does not exceed 30 hours for
drinking water samples
Time from sample collection to initiation of analysis for total
coliforms and fecal conforms in source water and heterotrophic
bacteria in drinking water does not exceed 8 hours
Yes
OM
No
Comments
-
E
V-39
-------
Element
All samples analyzed on day of receipt by laboratory, unless
laboratory receives sample late in day and then refrigerates sample
overnight and begins analysis •within holding time
6.5 Sample Information Form
Entered on sample information form in indelible ink:
- name of system (PWSS identification number if available)
- sample identification (if any)
- sample' site location
- sample type (e.g. routine, repeat, raw or process )
- date and time of collection
- analysis required
- disinfectant residual
- name of sampler and organization (if not water system)
- sampler's initials
- person(s) transporting sample from system to laboratory
(if not sampler)
- transportation condition (e.g. < 10°C, protection from
sunlight), if shipper used, shipping records available
- any remarks
6.6 Chain-of-Custody
Applicable regulations followed by collectors and laboratory
Yes
No
Comments
7, QUALlTV^ASSqUAKCE
Written QA Plan prepared, followed, and available for inspection
8. RECORDS AND BA^A »E1?OM3NG
8.1 Legal Defensibility
Compliance monitoring data legally defensible by keeping thorough
and accurate records
QA plan and/or SOPs describe policies and procedures used by
facility for record retention and storage
Chain-of-custody procedures used if samples expected to become
part of legal action
8.2 Maintenance of Records
Microbiological analyses records kept by or accessible to laboratory
for at least 5 years or until next certification data audit completed,
whichever is longer
Client water system notified before disposal of records
8.3 Sampling Records
_. '_.
V-40
-------
Element
Data recorded in ink with changes lined through such that original
entry visible and changes initialed and dated
Sampling records include:
- sample information form, from Section 6.5
- date and time of sample receipt by laboratory
- name of laboratory person receiving sample
- if any deficiency in sample condition noted, sample, at a
minimum, flagged
- if sample transit time exceeds 30 hours (8 hours for source
water samples), sample tagged
8.4 Analytical Records
Data recorded in ink with changes lined through such that original
entry visible and with changes initialed and dated
Analytical records include:
- laboratory sample identification
- date and time analysis begins
- laboratory and person(s) responsible for performing analysis
- analytical technique or method used
- all items marked QC
- results of analysis
8.5 Preventive Maintenance
Preventive maintenance and repair records for all instruments and
equipment kept for 5 years
Yes
No
Comments
9. ACTtONRESPONSB,TOtABORATORY»ESiaJ« _ \-
9.1 Testing Total Coliform-Positive Cultures
For the Total Colifonn Rule, all total coliform positive cultures
tested for presence of either fecal conforms or E. coli
9.2 Notification of Positive Results
For Total Colifonn Rule, proper authority notified promptly by
laboratory of positive total coliform, fecal coliform or E. coli results
Total coliform positive result based on confirmed phase for MTF
Technique and P-A Coliform Test or verified test for MF Technique
(no requirement for confirmation of positive Colilert/Oolisure, fecal
coliform or E. coli tests)
9.3 Invalidation of Total Coliform-Negative Sample
For Total Coliform Rule, proper authority notified when results
indicate non-coliforms may have interfered with total conform
analysis
V-41
-------
-------
Chapter VI
Critical Elements for Radiochemistry
1. Personnel
/./ Laboratory Supervisor
The laboratory supervisor should have at least a bachelor's degree with a major in chemistry or equivalent and at least
one year of experience in the analysis of drinking water for radiochemicals. The laboratory supervisor should have at
least a working knowledge of quality assurance principles. The laboratory supervisor has immediate responsibility to
insure that all laboratory personnel have demonstrated their ability to satisfactorily perform the analyses to which they
are assigned and that all data reported by the laboratory meet the required quality assurance criteria.
1.2 Laboratory Analyst
The laboratory analyst should have at least a bachelor's degree with a major in chemistry or equivalent and at least one
year of experience in the analysis of drinking water for radiochemicals. If the analyst is responsible for the operation of
analytical instrumentation, he or she should have completed specialized training offered by the manufacturer or another
qualified training facility or served a period of apprenticeship under an experienced analyst. The duration of this
apprenticeship is proportional to the sophistication of the instrument.
Before beginning the analysis of compliance samples, the analyst should demonstrate acceptable results for blanks, blind
spikes, precision, accuracy, method detection and specificity and satisfactory analysis on unknown samples.
1.3 Technician
The laboratory technician should have at least a high school diploma or equivalent, complete a method training program
under an experienced analyst and have six months bench experience in the analysis of drinking water samples.
Before beginning the analysis of compliance samples, the technician should demonstrate acceptable results for blanks,
blind spikes, precision, accuracy, method detection and specificity and satisfactory analysis on unknown samples.
1.4 Sampling Personnel
Personnel who collect samples should have training in the proper collection technique for all types of samples which they
collect. Their technique should be reviewed by experienced sampling personnel.
1.5 Analysts and Operators in Training
, Data produced by analysts and instrument operators while in the process of obtaining the required training or experience
are acceptable only when reviewed and validated by a fully qualified analyst or the laboratory supervisor.
1.6 Waiver of Academic Training Requirement
The certification officer may waive the.need for specified academic training, on a case-by-case basis, for highly
experienced analysts.
Training records should be maintained for all personnel. These should include all job related formal training taken by
the analyst which pertains to any aspect of his/her responsibilities, including but not limited to analytical methodology,
laboratory safety, sampling, quality assurance, data analysis, etc.
2. Laboratory Facilities
2.1 General
The analysis of compliance samples should be conducted in a laboratory where the security and integrity of the samples
and the data can be maintained. The laboratory facilities should be clean, have adequate temperature and humidity control
and adequate lighting at the bench top. The laboratory must have provisions for the proper disposal of chemical and
radiological wastes, including liquid scintillation cocktail mixtures. The appropriate type of exhaust hoods are required
where applicable.
VI-1
-------
A minimum of 150-200 square feet of laboratory space and 15 linear feet of usable bench space per analyst are
recommended. There should be sufficient bench space for processing samples. Workbench space should be convenient
to sink, water, gas, vacuum and electrical outlets free from surges.
Analytical and sample storage areas should be isolated from all potential sources of contamination. Any sample having
an emission rate in excess of 0.5 mrem/hr should be stored in a secured location away from drinking water samples.
There should be sufficient storage space for chemicals, glassware and portable equipment, sufficient floor and bench space
for stationary equipment and areas for cleaning materials.
2,2 Instrumentation .
Instruments must be properly grounded. Counting instruments must be located in a room other than the one in which
samples and standards are being prepared and in which other types of wet chemical analyses are being performed.
An uninterrupted power supply should be available for radiation counting equipment.
2.3 Preparation of Standards
In areas where radioactive standards are being prepared, care should be taken to minimize contamination of surfaces,
other samples and personnel. Either bench surfaces of an impervious material covered with adsorbent paper, or plastic
or fiberglass trays lined with adsorbent paper are acceptable.
3. Laboratory Equipment and Instrumentation
The laboratory is required to have the equipment, supplies and instrumentation necessary to perform the approved methods
for which it is certified.
3.1 Radiation Counting Instruments
The types of radiation counting systems needed to comply with measurements described in theregulations are as follows:
3.1.1 Liquid scintillation system: A liquid scintillation system is essential if the laboratory is to be certified
for the measurement of tritium in drinking water samples. It is recommended that the liquid scintillation system
have spectral analysis capabilities to establish proper regions of energy discrimination. The system must have
a sensitivity adequate to meet or exceed the detection limit requirements of CFR 141.25(c).
3.1.2 Gas-flow proportional counting system: A gas-flow proportional counting system may be used for the
measurement of gross alpha and gross beta activities, radium-226, radium-228, strontium-89, strontium-90,
radioactive ceshim,and iodine-131 as described in the reference in CFR 14.1.25(a). The detector may be either
a "windowless" (internal proportional counter) or a "thin window" type. A combination of shielding and a
cosmic (guard) detector operated in anticoincidence with the main detector should be used to achieve low
background beta counting capability. The alpha and beta background count of the system must be low enough
so that the sensitivity of the radioanalysis of water samples will meet or exceed the requirement of 40 CFR
141.25(c) with reasonable counting time (not more than 1,000 minutes).
3.1.3 Alpha scintillation counting system: '. For measurement of gross alpha activities and radium-226, a
scintillation system designed for alpha counting may be substituted for the gas-flow proportional counter
described. In such a system, a Mylar disc coated with a phosphor (silver-activated zinc sulfide) is either placed
directly on the sample or on the face of a photomtiltiplier tube, enclosed within a light-tight container, along with
the appropriate electronics (high voltage supply, preamplifier, amplifier, tinier and sealer).
3.1.4 Scintillation cell system: A scintillation system designed to accept scintillation flasks ("Lucas cells")
should be used for the specific measurement of radhim-226 by the radon emanation method. The system consists
of a light-tight enclosure capable of accepting the scintillation flasks, a detector (phototube), and the appropriate
electronics (high voltage supply, amplifier, timers, and sealers). The flasks (cells) needed for this measurement
may either be purchased from commercial suppliers or constructed by the laboratory.
3.1.5 Gamma spectrometer systems: Either a solid state lithium drifted germanium Ge(Li) detector or a high
VI-2
-------
purity intrinsic Ge(Hp) germanium detector connected to a multichannel analyzer is needed if the laboratory is
to be certified for analyses of manmade photon emitters.
A system with a lithium drifted germanium, or a high purity intrinsic germanium detector may be used for
measurement of manmade photon emitters if the efficiency of the detector is adequate to meet the detection limits
required at 40 CFR 141.25(c). These detectors should be shielded with a minimum of 10cm of iron or
equivalent. The multichannel analyzer, in addition to appropriate electronics should contain a memory of not
less than 4096 channels and at least one readout device.
3.1.6 Alpha Spectrometer System and Beta Scintillation: These counters and others as mentioned in
legislation.
4. General Laboratory Practices
4.1 Chemicals/reagents: Chemicals and reagents used must meet the specifications in the methods. If not specified,
then "Analytical reagent grade" (AR) or American Chemical Society (ACS) grade chemicals or better should be used.
Radioactive standards should be certified by the National Institute of Standards and Technology (NIST, formerly NBS)
or traceable to a certified source.
4.2 Reagent Water. The laboratory should have a source of reagent water, ASTM type 1,2,3 or equivalent, having a
minimum resistance of 10 megohms/cm at 25°C. The background radioactivity should be checked periodically and should
not be at a level which interfere with the radionuclide tests.
4.3 Glassware/Plastlcware: Specific requirements in the methods for the cleaning of glassware must be followed. If
there are no specifications, glassware should be acid washed then washed in detergent solution and thoroughly rinsed first
with tap water and then with reagent water. " '
4.4 Safety: Guidelines in the Laboratory Safety Manual, the Chemical Hygiene Plan or the Standard Operating
Procedures should include proper worker safety training and protection. When circumstances warrant the use of
protective equipment, this should include the use of gloves, laboratory coats, eye protection, and the proper pipetting
techniques.
5. Analytical Methods
The approved methods cited in the CFR at §141.25(a) and (b) must be used for the analysis of drinking water compliance
samples. These are listed in Table VI-1.
6. Sample Collection, Handling, and Preservation
Sample containers, preservatives and holding times in the methods must be followed. Table VI-2 lists critical elements
for sample handling including preservation. Sample preservatives should be checked for radioactive content.
7. Quality Assurance
Additional information is contained in Appendix H. Specific items are referenced throughout.
7.1 General Requirements
7.1.1 Availability of Records and Documents: The analytical methods, quality assurance manual and standard
operating procedures should be readily available to the analysts. All quality control data and records should be
available for inspection by the certification officer.
7.2 Performance Evaluation Studies Two types of performance evaluation studies are administered by NERL-LV:
7.2.1 Blind performance evaluation studies: Two water samples (A&B) are distributed twice each year.
These samples contain a mixture of alpha, beta, and gamma analytes. A laboratory must successfully analyze
at least one set of performance samples each year (either those distributed by NERL-LV or other PE samples
acceptable to the State) within the acceptance limits for each analyte for which the laboratory wishes to be
certified.
VI-3
-------
7.2.2 Other performance evaluation samples: Water samples containing a varied number of analytes are
distributed several times per year. A laboratory should successfully analyze at least two sets each year within
the acceptance limits in the regulations for each analyte for which the laboratory wishes to be certified.
7.2.3 Acceptance Limits: The radionuclide performance evaluation studies and their acceptance limits are
described in the draft document, Environmental Radioactivity Performance Evaluation Studies Program and
Radioactive Standards Distribution Program (EPA 600/4-81-004 and EPA 600/4-80-044), available from NERL-
LV.
7.3 Operating Manuals
Operating manuals and calibration protocols for counting instruments should be available to analysts and technicians.
7.4 Maintenance of Records
Calibration data and maintenance records on all radiation instruments and analytical balances should be maintained in a
permanent record. , , ,
7.5 Quality Control Requirements
The following are required for each analyte for which the laboratory is certified:
7.5.1 Duplicates: A minimum of one sample for every 10 or fewer compliance samples must be analyzed in
duplicate to verify internal laboratory precision for each method. The relative percent difference between
duplicates should be less than or equal to two sigma counting error for the pair of samples. If the difference
exceeds the two sigma counting error or 10% of the measured concentration, whichever is greater, prior
measurements are suspect; calculations and procedures should be examined and samples should be recounted.
All compliance samples, along with the duplicate analyses should be discarded if reanalysis of these samples
exceeds the prescribed limits for duplicate analyses or if they cannot be recounted..
7.5.2 Fortified Sample Matrix Matrix spikes are prepared by adding a known quantity of traceable standard
(if available) solution to an actual sample. They are prepared with the sample batch and processed identically
to the actual samples. The added concentration should not be less than the background. A matrix spike sample
must be prepared and used for each batch of samples, regardless of batch size. Agreement of the measured
value +/- 20% (95% CL) of the expected value indicates validity of the calibration curve. If the percent
recovery exceeds this limit, the result should be flagged as suspect due to matrix interference. Over time, an
effort should be made to spike samples from all the matrixes analyzed.
7.5.3 Counting and Background Check A counting standard and a background sample should be measured
with each set of 20 or fewer samples processed in a day.
7.5:4 Composited Samples Samples may be composited by the utility or the laboratory provided that sample
aliquots are filtered before preservation and preservative is added to the first and subsequent sample aliquots.
Generally, it is preferred to have the laboratory composite the samples to insure integrity over time. Analysis
of composited samples should be completed within one year after the first sample or within 30 days of the last
sample if the time between samples was less than 90 days.
7.6 Instrument Performance Charts/Records
Quality control performance charts or records should be maintained for each instrument.
VI-4
-------
7.7 QA Plan
The laboratory should prepare and follow a written QA plan (see Chapter IE). -
8. Records and Data Reporting
8.1 Legal Defensibility: Compliance monitoring data should be made legally defensible by keeping thorough and
accurate records. The QA plan and/or SOPs should describe the policies and procedures used by the facility for record
retention and storage. If samples are expected to become part of a legal action, chain of custody procedures should be
.used ( See Appendix A). ,
8.2 Maintenance of Records: Public Water Systems are required to maintain records of radionuclide analyses of
compliance samples for 10 years (40 CFR 141.33). The laboratory should maintain easily accessible records for five
years or until the next certification data audit is complete, whichever is longer. The client water system should be notified
before disposing of records so they may request copies if needed. This includes all raw data, calculations, and quality
control data. These data files may be either hard copy, microfiche or electronic. Electronic data should always be backed
up by protected tape or disk or hard copy. If the laboratory changes its computer hardware or software, it should make
provisions for transferring old data to the new system so that it remains retrievable within the time frames specified above.
Data which is expected to become part of a legal action will probably need to be maintained for a longer period of time.
Check with your legal counsel. See Appendix H, section 3.0, and Good Automated Laboratory Practices, EPA 2185,
Office of Information Management, Research Triangle Park, NC 27711, 8/10/95.
8.3 Sampling Records: Data should be recorded in ink with any changes lined through such that original entry is
visible. Changes should be initialed and dated. The following information should be readily available in a summary or
other record(s):
8.3.1 Date, location (including name of utility and PWSS ID #), site within the system, time of sampling,
name, organization and phone number of the sampler, and analyses required;
8.3.2 Identification of the sample as to whether it is a routine distribution system sample, check sample, raw
or finished water sample, repeat or confirmation sample or other special purpose sample;
8.3.3 Date of receipt of the sample;
8.3.4 Sample volume/weight, container type, preservation and holding time and condition on receipt;
8.3.5 pH and disinfectant residual at time of sampling (from plant records);
8.3.6 Transportation and delivery of the sample (person/carrier, conditions).
8.4 Analytical Records Data should be recorded in ink with any changes lined through such that original entry is
visible. Changes should be initialed and dated. The following information should be readily available:
8.4.1 Laboratory and persons responsible for performing analysis;
8.4.2 Analytical techniques/methods used;
8.4.3 Date and time of analysis;
8.4.4 Results of sample and quality control analyses;
8.4.5 Calibration and standards information;
8.4.6 Counting and detection limit data;
8.4.7 Results of analyses.
VI-5
-------
8.6 Computer programs: Computer programs should be verified initially and periodically by manual calculations and
the calculations should be available for inspection. Access to computer programs and electronic data should be limited
to appropriate personnel. "
9. Action Response to Laboratory Results
When a laboratory is responsible, either by contract or state policy, to report sample results which would cause a system
to be out of compliance, the proper authority should be promptly notified and a request should be made for resampling
from the same sampling point immediately. See Chapter HI.
VI-6
-------
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Sample Forms for f>n-Site Evaluation nf T,ahni-flfnrift
-------
Laboratoiy_
Location
Evahiator
Date
PERSONNEL
Position/Title
Laboratory
Director
Quality Assurance Officer
Section/Division
chief/Director
(if applicable)
Supervisory
Analyst
Chemical
Analyst(s)
Chemical
Techrucian(s)
Computer Support
Technician
Electronics
Support Technician
Name
Academic
Training
Present
Specialty
Years
Experience
Years
Experience
VI-11
-------
Laboratory
Location
Evaluator
Date
LABORATORY FACILITIES
Item
Laboratory
Electrical outlets
120V ac. grounded
Distilled or deionized water
or ASTM type 1, 2, or 3
Exhaust Hood
Vacuum source
Counting Room
Separate from wet
chemistry, sample
and standards
preparation area
Regulated power supply
Available
Yes
No
Comments
VI-12
-------
Evaluator_
Location
Date
GENERAL LABORATORY EQUIPMENT AND INSTRUMENTS
Item
Analytical Balance
0. 1 mg sensitivity
stable base
ASTM type 1 or 2 weights or better
pH meter
• ±0.5 units
readability ±0.1 units
line or battery
Conductivity meter
Readable in ohms or mhos
Range of 2 ohms or mhos
Line or battery
Drying oven
gravity or convection
controlled from room
temp to 180°C or higher
(±2°C)
Infrared lamp
may be substituted for drying oven
Desiccator
Glass or plastic
Hot plate
temperature control
Refrigerator
Magnetic Stirrer
variable speed
Teflon coated stir bar
Balance, top loading
Glassware
Thermometers
Muffle furnace to 450°C
Centriiuge
to 3000 rpm
to hold 4 x 50 mL
No.of
Units
-. .-.
Manufacturer
Model
Satisfactory
Yes No
.-•-• ' -:_
VI-13
-------
Laboratory_
Location
Date
Evaluator
ALL INSTRUMENTATION
Are operating manuals readily
available to the operator
Are calibration protocols available
to the operator
Are calibrations kept in a permanent
control chart
Are permanent service maintenance
records kept
Yes No
Comments
VI-14
-------
Laboratory
Location
Date
Evaluator
THIN WINDOW GAS-FLOW PROPORTIONAL COUNTER
Instrument
number
Calibration Standard
Type:
Alpha
Beta
Supplier:
Alpha
Beta
Manufacturer
Counting Gas
Model
Window
Density
(g/cm2)
Calibration Frequency1
D
W
M
Other
Year
Sample Changing
Manual
Automatic
Capacity •
Instrument Background
Alpha Beta
Operating Voltage cpm Operating Voltase com
Service Maintenance Frequency2
Q
s
A
Other
Condition*
G
R N
WINDOWLESS GAS-FLOW PROPORTIONAL COUNTER
Instrument
number
Calibration
Standard
Type:Alpha
Beta
Supplier:
Alpha
Beta
Manufacturer
Counting Gas
Model
Window
Density
(g/cm2)
Calibration Frequency*
D
W
M
Other
Year
Sample Changing
Manual
Automatic
Capacity
Instrument Background
Alpha Beta
Operating cpm Operating cpm
Voltage Voltage
Service Maintenance Frequency2
0
S
A Other
Condition3
G
R N
1. Daily, Weekly, Monthly.
2. Quarterly, Semiannually, Annually.
3. Good, operating but needs Repair, Not operating
VI-15
-------
Laboratory_
Location
Date
Evaluator
LIQUID SCINTILLATION COUNTER
Instrument
number
Calibration Standard
Type:
Supplier:
Manufacturer
Model
D
W
M
Other
Year
Sample Changing
Manual
Service Maintenance Frequency2
Q
S
A
Other
Auto
Capacity
Condition3
G
R N
ALPHA SCINTILLATION COUNTER
Instrument
number
Calibration Standard
Type:
Supplier:
Manufacturer
Model
Calibration Frequency1
D
W
M
Other
Year
Sample Changing
Manual
Service Maintenance Frequency2
Q
S
A
Other
Auto
Capacity
Condition3
G
R
N
RADON-GAS COUNTING SYSTEM
System
number
Gas counting cells/system
Manufacturer of gas counting
cell
Calibration Freouency1
D
W
M
Other
Counting Instrument
Make Model Year
Service Maintenance Frequency*
0
S
A
Other
Condition3
G
R
N
1. Daily, Weekly, Monthly.
2. Quarterly, Semiannually, Annually.
3. Good, operating but needs Repair, Not operating
VI-16
-------
Laboratory Date
Location Evaluator
GAMMA SPECTROMETER SYSTEM
Detector System
Calibration Standard
Type
Supplier
System Number
Type Make Model Year Size
Analyzer System
Make Model Year Channels
Calibration Frequency Service Maintenance Frequency Condition
D w M Other Q S A Other OR N
OTHER APPROVED DETECTOR
Detector System
Calibration Standard
Type
Supplier
System Number
Type Make Model Year Size
Analyzer System
Make Model Year Channels
Calibration Frequency Service Maintenance Frequency Condition
D W M Other Q S A Other G R N
1. Daily, Weekly, Monthly.
2. Quarterly, Semiannually, Annually.
3. Good, operating but needs Repair, Not operating
VI-17
-------
Laboratory
Location
Date
Evaluator
SAMPLE HANDLING AND PRESERVATION
Parameter
Gross Alpha Activity
Gross Beta Activity
Strontium-89
Stronlium-90
R«dium-226
Radium-228
Iodine-131
Tritium
Photon Emitters
b.
d.
c.
Container
Used
Preservative Used
NONE
NONE
Comments
r
Satisfactory
Yes No
VI-18
-------
Laboratory
Location
Date
Evaluator
METHODOLOGY
Parameter
Gross Alpha Activity
Gross Beta
Activity
Strontium-89
Strontium-90
Radium-226
Radium-228
Cesium-134
Iodine- 131
Tritium
Uranium
Photon
Emitters
Identify:
a.
b.
c.
d.
e.
Sample
Load/Mo
Method* Used - Cite Edition, Year, and Page
EPA SMI ASTM USGS DOE Other
Satifactory
Yes No
1 - Methods used must be referenced in the National Primary Drinking Water Regulations (40 CFR 141.25)
VI-19
-------
Laboratory^
Location
Date
Evaluator
QUALITY CONTROL
Htm
Participation in
performance
evaluation and
Blind PE
studies
Reporting Period:
to
Soikcs
Failed PE studies
Control charts
Calibration and
Performance Evaluation Studies
A1 B1
Sr-89
Sr-90
Ra-226
Ra-228
Cs-134
Cs-137
Co-60
Ba-133
Zn-6S
Tritium
1-131
Frequency
Yes
•
No
Blind PE Studies
Gross Alpha
Gross Beta
Sr-89
Sr-90
Ra-226
Ra-228
Uranium
Cs-134
Cs-137
Co-60
Written QA Plan
implemented and
available for review
Comments
A1
B1
Satisfactory
Yes No
1 - Scheduled frequency of participation by the laboratory, times per year.
2 - Number of acceptable performance results in the past year, where an acceptable result is a normalized deviation from the known value of £3.0
Sigma.
VI-20
-------
1
Laboratory
Location
Date
DATA REPORTING
Evaluator
Item
Records kept for 10 years
Actual laboratory reports
Tabular Summary
Information included
Date
Place of sampling
Time of sampling
Sampler
Date of sample receipt
Date of analysis
Type of analysis
Laboratory & person
responsible
Other reported data
Other reported data
Method(s) used
Results
Comments: systems used, frequency, etc.
VI-21
-------
-------
Appendix A
Chain-of-Custody Evaluations
A. Introduction
Written procedures for sample handling should be available and followed whenever samples are collected, transferred,
stored, analyzed or destroyed. For the purposes of litigation, it is necessary to have an accurate written record to trace
the possession and handling of samples from collection through reporting. The procedures defined here represent a means
to satisfy this requirement.
A sample is in someone's "custody" if:
1. It is in one's actual physical possession;
2. It is in one's view, after being in one's physical possession;
3. It is one's physical possession and then locked up so that no one can tamper with it;
4. It is kept in a secured area, restricted to authorized personnel only.
B. Sample Collection, Handling and Identification
1. It is important that a minimum number of persons be involved in sample collection and handling. Guidelines
established in standard manuals for sample collection preservation and handling should be used (e.g., EPA NPDES
Compliance Sampling Inspection Manual, MCD 51, Standard Methods for Examination of Water and Wastewater).
Field records should be completed at the time the sample is collected and should be signed or initialed, including the
date and time, by the sample collectors). Field records should contain the following information:
a. Unique sample or log number;
b. Date and time;
c. Source of sample (including name, location and sample type);
d. Preservative used;
e. Analyses required;
f. Name of collectors);
g. Pertinent field data (pH, DO, Cl residual, etc.);
h. Serial number on seals and transportation cases;
i. Comments.
2. Each sample is identified by affixing a pressure sensitive gummed label or standardized tag on the containers). This
label should contain the sample number, source of sample, preservative used, and the collectors') initials. The
analysis required should be identified. Where a label is not available, the sample information should be written on
the sample container with an indelible marking pen. An example of a sample identification tag is illustrated in Figure
A-l.
3. The closed sample container should then be placed in a transportation case along with the chain-of-custody record
A-l
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form, pertinent field records, and analysis request form. The transportation case should then be sealed and labeled.
All records should be filled out legibly in waterproof pen. The use of locked or sealed chests will eliminate the need
for close control of individual sample containers. However, there will undoubtedly be occasions when the use of a
chest will be inconvenient. On these occasions, the sampler should place a seal around the cap of the individual
sample container which would indicate tampering if removed.
C. Transfer of Custody and Shipment
1. 'When transferring the possession of the samples, the transferee must sign and record the date and time on the chain-
of-custody record. Custody transfers, if made to a sample custodian in the field, should account for each individual
sample, although samples may be transferred as a group. Every person who takes custody must fill in the appropriate
section of the chain-of-custody record.
2. The field custodian (or field sampler if a custodian has not been assigned) is responsible for properly packaging
and dispatching samples to the appropriate laboratory for analysis. This responsibility includes filling out,
dating, and signing the appropriate portion of the chain-of-custody record. A recommended chain-of-custody
format is illustrated in Figure A-2.
3. All packages sent to the laboratory should be accompanied by the chain-of-custody record and other pertinent
forms. A copy of these forms should be retained by the field custodian (either carbon or photocopy).
4. Mailed packages can be registered with return receipt requested. If packages are sent by common carrier,
receipts should be retained as part of the permanent chain-of-custody documentation.
5. Samples to be transported must be packed to prevent breakage. If samples are shipped by mail or by other
common carrier, the shipper must comply with any applicable Department of Transportation regulations. (Most
water samples are exempt unless quantities of preservatives used are greater than certain levels.) The package
must be sealed or locked to prevent tampering. Any evidence of tampering should be readily detected if
adequate sealing devices are used.
6. If the field sampler delivers samples to the laboratory, custody may be relinquished to laboratory personnel.
If appropriate personnel are not present to receive the samples, they should be locked in a designated area of
the laboratory to prevent tampering. The person delivering the samples should make a log entry stating where
and how the samples were delivered and secured. Laboratory personnel may then receive custody by noting in
a logbook, the absence of evidence of tampering, unlocking the secured area, and signing the custody sheet.
D. Laboratory Sample Control Procedures
Sample control procedures are necessary in the laboratory from the time of sample receipt to the time the sample is
discarded. The following procedures are recommended for the laboratory:
1. A specific person must be designated as custodian and an alternate designated to act as custodian in the
custodian's absence. All incoming samples must be received by the custodian, who must indicate receipt by
signing the accompanying custody/control forms aad who must retain the signed forms as permanent records.
2. The custodian must maintain a permanent logbook to record, for each sample, the person delivering the sample,
the person receiving the sample, date and time received, source of sample, date the sample was taken, sample
identification log number, how transmitted to the laboratory, and condition received (sealed, unsealed, broken
container, or other pertinent remarks). This log should also show the movement of "each sample within the
laboratory; i.e., who removed the sample from the custody area, when it was removed, when it was returned,
and when it was destroyed. A standardized format should be established for logbook entries.
A-2
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3. A clean, dry, isolated room, building, and/or refrigerated space that can be securely locked from the outside
must be designated as a "custody room."
4. The custodian must ensure that heat-sensitive samples, light-sensitive samples, radioactive samples, or other
sample materials having unusual physical characteristics, or requiring special handling, are properly stored and
maintained prior to analysis.
5. Distribution of samples to the analyst performing the analysis must be made by the custodian.
6. The laboratory area must be maintained as a secured area, restricted to authorized personnel only.
7. Laboratory personnel are responsible for the care and custody of the sample once it is received by them and must
be prepared to testify that the sample was in their possession and view or secured in the laboratory at all times
from the moment it was received from the custodian until the time that the analyses are completed.
8. Once the sample analyses are completed, the unused portion of the sample, together with all identifying labels,
must be returned to the custodian. The returned tagged sample must be retained in the custody room until
permission to destroy the sample is received by the custodian.
9. Samples will be destroyed only upon the order of the responsible laboratory official when it is certain that the
information is no longer required or the samples have deteriorated. (For example, standard procedures should
include discarding samples after the maximum holding time has elapsed.) The same procedure is true for sample
tags. The logbook should show when each sample was discarded or if any sample tag was destroyed.
10. Procedures should be established for internal audits of sample control information. Records should be examined to
determine traceability, completeness, and accuracy.
A-3
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Figure A-1 Sample Identification Tag Examples
O
U.S. EPA REGION
GENERAL CHEMISTRY
Official Sample No.
Ul
U
CC
o
tn
Date and Time
Sampler's Signature Office
Other Parameters:
PH
Cond
TS
OS
SS
BODa
Turb
Color
Acid
Alk
8O4
Cl
F
Cr. + 6
ElOOs
U.S. EPA REGION
MICROBIOLOGY
Official Sample Mo.
111
o
cc
3 . .
CO ,
Date and Time
Sampler's Signature Office
Tot. Colif.
Fecal Colif.
Fecal Strep.
Salmonella
U.S. EPA REGION
PESTICIDES. ORGANICS
Official Sample No.
UJ
U
cc
-, . . ... ...
0
(O
Date and Time
Sampler's Signature Office
Pesticides
PCB's:
Organics:
EPA
Station No. Date Time Sequence No.
Station Location
BOD rentals;
Solids , . . ,Qil ?n
-------
Figure A-2 Chain-of-Custody Record
Survey
Station
Number
Station Location .
Date '
Relinquished by: Signature
Relinquished by: Signature
Relinquished by: Signature
Relinquished by: Signature
Dispatched by:
Time
Samplers: Signature
Sample Type
Water
Comp
Grab.
Air
Seq. No.
No. Of
Containers
Received by: Signature
Received by: signature
Received by: Signature
Received by Mobile Laboratory for Field analysis:
Signature
Date/Time
Received for Laboratory by: Signature
Analysis
Required
Date/Time
Date/Tune
Date/Time
Date/Time
Date/Time
Method of Shipment:
Distribution: Orig. —Accompany Shipment, 1 Copy—Survey Coordinator Field Files
A-5
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Appendix B
Recommended Protocol for Regions Conducting On-Site Laboratory Evaluations
Before conducting the on-site evaluation, the Region should:
• Plan all the required activities to be completed during the assessment.
• Hold a pre-evaluation conference with appropriate laboratory and field activity representatives to establish a schedule that
would have a minimum impact on the laboratory activities. .
• Request and review appropriate records.
• Request that a variety of tests be scheduled during the on-site evaluation.
• Arrange for the laboratory staff to be available during the on-site visit.
During the on-site visit, the team shall:
• Conduct an opening conference or entrance interview.
• Evaluate the procedures and equipment used for those specific analyses for which the laboratory has requested certification,
using the criteria in this manual.
• Review the records and written standard operating procedures for compliance with the required sampling frequency, sample
collection, sample holding times, and if appropriate, resample notification.
• Perform a data audit on at least one sample and one PE sample for at least one method but preferably for each method the
laboratory performs.
• Insure that the laboratory has a QA plan in effect by:
Determining if the laboratory has written procedures (QA plan or equivalent) for conducting its quality assurance
program.
Examining the quality assurance data to determine if the quality assurance program is being implemented.
• Complete the on-site checklists and other evaluation forms during the visit (see'Chapters W, V, and VI).
• Conduct a closing conference or exit interview in which the auditors review the results of the evaluation with the director of
the laboratory, the director of State water supply activities, and appropriate staff members. The review should:
Discuss any deviations in the observed procedures and records.
Recommend changes in equipment and supply needs, staffing requirements, and facility improvements, if
necessary.
Discuss possible assistance the Region can provide the laboratory.
, Discuss a time frame for corrective actions and response.
Evaluation Report for Principal State Laboratories and Laboratories in Non-Primacy States
After an on-site inspection, the evaluation team should prepare a narrative report and action memorandum. This report should
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contain all information pertinent to the evaluation and also recommend the certification status for all analyses evaluated. The
report should then be forwarded for evaluation to the Certification Program Manager for review. After reviewing and, if
necessary, revising the report, it should be forwarded to the Certification Authority for signature.
The Certification Authority should decide the certification status of the laboratory within time constraints on page IH-7 and notify
the State. The State should be sent the complete report. If the report indicates that the laboratory should not be certified for an
analysis, the Certification Authority should give the specific reasons.
The narrative report should be attached to each copy of the completed evaluation form. It should include the general headings
and information listed below.
Title Page
The title page should contain the following:
Title: Report of an on-site evaluation of the
(name of laboratory)
At: (city, state, and zip code) ,
On: (date)
By: (name, title, organization, and
address of the certification team)
Certification Status
List either "Certified", "Provisionally Certified", "Administratively/Interim Certified", or "Not Certified" for each
contaminant evaluated or if applicable (for VOCs, for instance) for each class of compounds evaluated.
List of Deviations
List each deviation by item number used on the evaluation checklists. Describe the exact deviation and recommended changes.
Remarks
Recommend improvements which, while not affecting certification status, would improve laboratory operation. Other remarks
might include reasons for failing the on-site evaluation, special recognition for outstanding performance, and description of
unusual tests.
List of Personnel
List name and title of personnel along with the individual tests that each normally performs. Also, identify the critical laboratory
personnel.
Signature . ...
Team members should sign the report.
Distribution
Copies of this report should be distributed to the State requesting the evaluation. For local laboratories in non-primacy States,
reports should be distributed to appropriate Regional personnel.
Annually, each Region should submit to OGWDW a listing of laboratories in the Region having U.S.'EPA certification. The
listing should include the names and location of each laboratory, and its certification status for all regulated contaminants. In
addition, Regions should notify OGWDW of all changes in status soon after they occur so that OGWDW can maintain an updated
list of certification status.
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Appendix C
Definitions and Abbreviations
ASTM: American Society of Testing and Materials
AWWA: American Water Works Association
NERL-Ci: U.S. EPA National Exposure Research Laboratory in Cincinnati, Ohio (ORD).
NERL-LV: U.S. EPA National Exposure Research Laboratory in Las Vegas, Nevada (ORD).
NPDWR: National Primary Drinking Water Regulations.
OGWDW: U.S. EPA Office of Ground Water and Drinking Water.
ORD: U.S. EPA Office of Research and Development.
SDWA: The Safe Drinking Water Act as amended (42 U.S.C. 300f et seq.).
Accuracy: A measure of the closeness of an individual measurement or the average of a number of measurements to the true
value. Accuracy includes a combination of random error (precision) and systematic error (bias) components which are due to
sampling and analytical operations. Refer to Standard Methods, Data Quality Section for a more detailed explanation.
Administrator: The administrator of the United States EPA or her/his authorized representative. See 40 CFR 142.2.
Agency: The U.S. EPA. See 40 CFR 142.2.
Auditor - A person who evaluates laboratories to determine if they meet the criteria to be certified. This person should be an
experienced professional, who has effective communication skills, experience in quality assurance, the analytical techniques being
evaluated, and familiarity with the drinking water regulations and this manual.
Bachelor Degree or Equivalent: A college degree with an equivalent 30 semester hours in a specific discipline. Equivalent
is at least four years of experience in a specific scientific discipline.
Bias: The systematic or persistent distortion of a measurement process which causes errors in one direction.
Certification Authority: (CA) The person or designee who has the authority to certify laboratories conducting drinking water
analyses and to certify the officials of the State responsible for the State's certification program in accordance with Section 1412
of the Safe Drinking Water Act.' This authority is delegated to the Regional Administrator but may be redelegated.
Certification Program Manager: (CPM) The person responsible for managing the certification program whichnncludes
tracking the certification status of the State laboratories, ensuring that the regional and State certification officers are qualified
and reviewing the certification evaluation reports.
Certification Officer: (CO) A State or Federal laboratory auditor who has passed the NERL certification officers training course
(limited at this time to chemistry and microbiology). This person provides information to the CA or CPM for the purpose of
making decisions on the certification status of a laboratory.
CFR: Code of Federal Regulations - A compilation of regulations is revised each time a regulation is promulgated. It is
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published every year in July.
Confirmation: Verification of the presence of a component through the use of an analytical technique based on a different
scientific principle from the original method (e.g., second column, alternate wavelength or detector, etc.)
Data Audit: A qualitative and quantitative evaluation of the documentation and procedures associated with measurements to
verify that the resulting data are acceptable.
Data Quality Objectives: qualitative and quantitative specifications used to design a study that will limit uncertainty to an
acceptable level.
Data Reduction: The process of transforming the number of data items by arithmetic or statistical calculations, standard curves,
concentration factors, etc. and collation into a more useful form. Data reduction is irreversible and generally results in the loss
of detail.
Detection: Any concentration of an analyte which equals or exceeds the laboratory's detection limit. For VOCs, detection limit
is defined as 0.0005 mg/L.
Drinking Water Laboratory: A laboratory that analyses samples as part of compliance monitoring for a public water supply.
Federal Indian Land: Areas which for regulatory purposes are treated as independent States. On these lands, the Indian tribe
has a Federally recognized governing body carry ing out government duties and powers.
Holding time: The allowed time from when a sample was taken (or extracted) until it must be analyzed.
IDC: Initial Demonstration of Capability - before analyzing compliance samples an analytical team must demonstrate acceptable
precision, accuracy, sensitivity, and specificity for the method to be used.
LRB - Laboratory Reagent Blank: (Method blank) An aliquot of reagent water or other blank matrix that is treated exactly
as a sample to determine if method analytes or other interferences are present.
LFB - Laboratory Fortified Blank: (Spike) An aliquot of reagent water or other blank matrix to which known quantities of
the method analytes are added in the laboratory. The LFB is analyzed exactly like a sample to determine whether the method
is in control.
MCL: Maximum contaminant level means the maximum permissible level of a contaminant in water which is delivered to any
user of a public water system. See 40 CFR Part 141.2.
MCLG: Maximum contaminant level goal means the maximum level of a contaminant in drinking water at which no known or
anticipated adverse effect on the health of persons would occur, and which allows an adequate margin of safety. Maximum
contaminant level goals are nonenforceable health goals. See 40 CFR 141.2.
Method Detection Limit: (MDL) is defined as the minimum concentration of a substance that can be measured and reported with
99% confidence that the analyte concentration is greater than zero. The MDL is determined from analysis of a sample in a given
matrix containing this analyte. See 40 CFR 136 App. B.
Monitoring Trigger: The concentration of a regulated contaminant which triggers additional monitoring
NELAC: National Environmental Laboratory Accreditation Conference - a voluntary organization of State, Federal and other
groups to establish mutually acceptable standards for accrediting environmental laboratories.
Performance Evaluation Samples (PEs): (Proficiency test sample) A sample provided to a laboratory for the purpose of
C-2
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demonstrating that the laboratory can successfully analyze the sample within specified acceptance limits specified in the
regulations. The qualitative and/or quantitative composition of the reference material is unknown to the laboratory at the time
of the analysis. See 40 CFR Part 141.2.
Precision: The measure of mutual agreement among individual measurements.
Primacy: Primary responsibility for administration and enforcement of primary drinking water regulations and related
requirements applicable to public water systems within a State
Principal State Laboratory System: All facilities, whether part of the State laboratory or contracted to the State, producing
data for the State and certified by the EPA, fulfilling the requirements for Primacy as listed in the 40 CFR 142.10(b)(4).
Public Water System: A system for the provision to the public of piped water for human consumption, if such system has at
least fifteen service connections or regularly serves an average of at least twenty-five individuals daily at least 60 days out of the
year. See 40 CFR Part 141.2.
Quality Assurance: An integrated system of management activities involving planning, quality control, quality assessment,
reporting and quality improvement to ensure that a product or service meets defined standards of quality with a stated level of
confidence.
Quality Control: The overall system of technical activities whose purpose is to measure and control the quality of a product
or service so that it meets the needs of the users; operational techniques and activities that are used to fulfill requirements for
quality.
QA Plan: A comprehensive plan detailing the aspects of quality assurance needed to adequately fulfill the data needs of a
program. This document is required before the laboratory is certified.
Regulatory Level: A concentration of a contaminant which is cited in the Federal Regulations (e.g., MCL, detect, etc.)
Shall: Denotes a mandatory requirement.
Should: Denotes a guideline or recommendation.
Standard Operating Procedure: A written document which details the method of an operation, analysis or action whose
techniques and procedures are thoroughly prescribed and which is officially approved as the method for performing certain
routine or repetitive tasks.
Third Party Auditor: Person or persons, not affiliated with a Region or State, who is designated by the Region or State to audit
a laboratory. This person must pass the certification training course prior to auditing any laboratory unless he or she is a part
of an audit team which includes a Regional/State certification officer. The third party auditor must also meet the
educational/experience requirements specified in this manual. The certification decision remains with the Region.
Third Party Expert: Any person not designated as a certification officer or auditor, who is requested by the Region to assist
in the audit of a laboratory because of his or her expertise in a particular area (e.g., asbestos). This person is not required to
take the certification officers' course if he or she is part of an audit team which includes a certification officer.
"Unregulated" Contaminants: Contaminants for which monitoring is required but which have no MCL.
C-3
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Appendix D
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C: 20460
PR0^&< Office of Ground Water and Drinking Water
Technical Support Center
January 16, 1997
OFFICE OF
WATER
MEMORANDUM
SUBJECT: The Use of "Third-Parties" in the Drinking Water Laboratory Certification
Progr
FROM:
Office olCrround Water and DrinkineHVater
TO: Water Supply Representatives, Regions I-X
Certification Authorities, Regions I-X
Quality Assurance Officers, Regions I-X
Regional laboratories, Regions I-X .
Purpose
This memorandum updates and clarifies the guidance memorandum from Michael Cook
dated December 5, 1989 on "Third-Party Certification for Laboratories in Primacy States."
Action
Under 40 CFR 142.10(b) (3), if a state does not perform all analytical measurements in
its own laboratory, it must establish and maintain a program for the certification of
laboratories as a condition for receiving and maintaining authority to administer the Safe
Drinking Water Act in lieu of EPA (primacy). This memorandum notifies states with primacy
that they may contract with other organizations (third parties) to assist the state in fulfilling
this requirement. The authority for making certification decisions however, must remain
with the state.
Discussion
Several states have asked USEPA its position on the use of third-parties, i.e., private
sector organizations which assist the states with their certification program. OGWDW realizes
that dwindling state resources may necessitate assistance from third-parties in the State
certification programs. Consistent with the regulatory requirement at 40 CFR 142.10(b),
providing for the "establishment and maintenance of a state program for the certification of
laboratories," the state must retain ultimate authority to decide whether individual laboratories
will be certified: this decision may not be abdicated to the third party.
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This Office will not pass judgment on any specific third-party program. It is the
responsibility of each primacy state to assess the qualifications of the third-party. In assessing
whether to choose a particular third-party, the state should consider, as a minimum, the
following items which are described in the Manual for the Certification of Laboratories
Analyzing Drinking Water:
o Ability to provide technical assistance and training
o Availability of records for review by the state
o Quality assurance program
o Freedom from conflicts of interest
o EPA policy, which provides that the auditor should pass an appropriate course
on how to audit in the discipline for which he or she will be auditing.
o Experience of the auditor.
The auditor should be an experienced professional with at least a
bachelor's degree or equivalent education/experience in the discipline for
which he or she audits.
The auditor should have recent laboratory experience
Any state certification program using third party assistance should meet the
requirements in the Manual for the Certification of Laboratories Analyzing Drinking Water just
as it would if it were using state employees to perform these functions. The Regions should
assist the state and third-party agent to assure that the certification program meets EPA
guidelines.
Regions and states should be sensitive to potential conflict-of-interest problems between
a third-parties and evaluated laboratories. For instance, inspectors employed by firms that
provide analytical services hi the drinking water area should not be put hi the position of
passing judgement on their competitors.
Further Information
If you have questions or need additional information or assistance, please contact the
OGWDW Technical Support Center at 513-569-7904.
D-2
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INORGANICS
(40 CFR 141.23)
Asbestos
Cyanide
Fluoride
Nitrate
Nitrite
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Mercury
Selenium
Thallium
(40 CFR 141.89)
Copper
Lead
Conductivity
Calcium
Alkalinity
Orthophosphate
Silica
VOLATILE ORGANICS
(40 CFR 141.24)
THMs
Benzene
Carbon tetrachloride
Chlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
1,2-Dichloroethane
1,1 -Dichloroethylene
cis-1,2-Dichloroethylene
trans-1,2-Dichloroethylene
Dichloromethane
1,2-Dichloropropane
Ethylbenzene
Styrene
Tetrachloroethene
Toluene
1,2,4-Trichlorobenzene
1,1,1 -Trichloroethane
1,1,2-Trichloroethane
Trichloroethene
Vinyl chloride
Xylenes
Appendix £
Required Analytical Capability for Principal State Laboratory Systems
MICROORGANISMS
(40 CFR 141.21)
Total coliforms
Escherichia coli or fecal coliforms
Heterotrophic bacteria
SOCs
(40 CFR 141.24)
Alachlor
Atrazine
Benzo(a)pyrene
Carbofuran
Chlordane
2,4-D
Di(2-ethylhexyl)adipate
Di(2-ethylhexyl)phthalate
Dibromochloropropane
Dalapon
Dinoseb
Dioxin (2,3,7,8-TCDD)
Diquat
Endothall
Endrin
Ethylenedibromide
Glyphosate
Heptachlor
Heptachlor epoxide
• Hexachlorobenzene
Hexachlorocyclopehtadiene
Lindane
Methoxychlor
Oxamyl
PCBs (as decachlorobiphenyl)
Pentachlorophenol
Picloram
Simazine
Toxaphene
2,4,5-TP
RADIONUCLIDES
(40 CFR 141.25)
Gross Alpha
Uranium
Gross Beta
Cesium-134
Strontium-89
Iodine-131
Strontium-90
Tritium
Other beta/photon emitters
Radium-226/228
E-l
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UNREGULATED VOCs
(40 CFR 141.40)
Bromobenzene
Bromodichloromethane
Bromoform
Bromomethane
Chlorodibromomethane
Chloroethane
Chlorofonn
Ghloromethane
o-Chlorotoluene
p-Chlorotoluene
1,1-Dichloroethane
1,3-Dichloropropane
2,2-Dichloropropane
1,1 -Dichloropropene
1,3-Dichloropropene(c/t)
m-Dichlorobenzene
Dibromoinethane
1,1,1,2-Tetrachloroethane
1,1,2,2-Tetrachloroethane
1,2,3-Trichloropropane
UNREGULATED lOCs
(40 CFR 141.40)
Corrosivity
Sodium
Sulfate
PHASE 6A
(Proposed 7/29/94)
Free & Total Chlorine
Combined Chlorine
Chlorine Dioxide
Trihalomethanes
Haloacetic Acids
Bromate
Chlorite
Total Organic Carbon
Alkalinity
Bromide
Appendix F
Unregulated, Proposed and Secondary Contaminants
UNREGULATED SOCs
(40 CFR 141.40)
Aldicarb
Aldicarb Sulfoxide
Aldicarb Sulfone
Aldrin
Butachlor
Carbaryl
Dicainba
Dieldrin
3-Hydroxycarbofuran
Methomyl
Metolachlor
Metribuzin
Propachlor
RADIONUCLIDES
(Proposed 7/18/91)
(40 CFR 141.25)
Radon
Uranium
(40 CFR 141.44)
Lead-210
SECONDARY CONTAMINANTS
Aluminum
Chloride
Color
Copper
Fluoride
Foaming Agents ,
Iron i
Manganese
Odor
pH
Silver
Sulfate
Total Dissolved Solids (TDS)
Zinc
Contaminants to be Monitored at the Discretion of the State
1,2,4-Trimethylbenzene
1,2,3-Trichlorobenzene
n-Propylbenzene
n-Butylbenzene
Naphthalene
Hexachlorobutadiene
1,3,5-Trimethylbenzene
p-Isopropyltoluene
Isopropylbenzene
tert-Butylbenzene
sec-Butylbenzene
Fluorotrichloromethane
Dichlorodifluoromethane
Bromochloromethane
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Appendix G
Analytical Methods for Microbiology
1. Total Coliform Rule (40 CFR 141.21(f))
(f) Analytical methodology. (1) The standard sample volume required for total coliform analysis, regardless of
analytical method used, is 100 mL.
(2) Public water systems need only determine the presence or absence of total conforms; a determination of total
conform density is not required.
(3) Public water systems must conduct total coliform analyses in accordance with one of the analytical methods in the
following table. These methods are contained in the 18th edition of Standard Methods for the Examination of Water and
Waste-water, 1992, American Public Health Association, 1015 Fifteenth Street NW, Washington, D.C. 20005. A
description of the Colisure Test may be obtained from the Millipore Corporation, Technical Services Department, 80
Ashby Road, Bedford, MA 01730. The toll-free phone number is (800) 645-5476.
Organism
Total Coliforms1
Methodology
Total Coliform Fermentation Technique 2'3'4
Total Coliform Membrane Filter Technique
Presence-Absence (P-A) Coliform Test4'5
ONPG-MUG Test6
Colisure Test7
9221A,B
9222A,B,C
9221D
9223
1 The time from sample collection to initiation of analysis may not exceed 30 hours. Systems are encouraged but not
required to hold samples below 10°C during transit.
2 Lactose broth, as commercially available, may be used in lieu of lauryl tryptose broth, if the system conducts at
least 25 parallel tests between this medium and lauryl tryptose broth using the water normally tested, and this
comparison demonstrates that the false-positive rate and false-negative rate for total conforms, using lactose broth,
is less than 10 percent.
3 If inverted tubes are used to detect gas production, the media should cover these tubes at least one-half to two-thirds
after the sample is added.
4 No requirement exists to run the completed phase on 10 percent of all total coliform-positive confirmed tubes.
5 Six-times formulation strength may be used if the medium is filter-sterilized rather than autoclaved.
6 The ONPG-MUG Test is also known as the Autoanalysis Colilert System.
7 The Colisure Test must be incubated for 28 hours before examining the results. If an examination of the results at
28 hours is not convenient, then results may be examined at any time between 28 hours and 48 hours.
(4) [Reserved]
(5) Public water systems must conduct fecal conform analysis in accordance with the following procedure. When the
MTF Technique or Presence-Absence (PA) Coliform Test is used to test for total coliforms, shake the lactose-positive
presumptive tube or P-A [bottle] vigorously and transfer the growth with a sterile 3-mm loop or sterile applicator stick
into brilliant green lactose bile broth and EC medium to determine the presence of total and fecal coliforms, respectively.
For EPA-approved analytical methods which use a membrane filter, transfer the total coliform-positive culture by one
G-l
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of the following methods: remove the membrane containing the total conform colonies from the substrate with a sterile
forceps and carefully curl and insert the membrane into1 a tube of EC medium (the laboratory may first remove a small
portion of selected colonies for verification), swab the entire membrane filter surface with a sterile cotton swab and
transfer the inoculum to EC medium (do not leave the cotton swab in the EC medium), or inoculate individual total
coliform-positive colonies into EC Medium. Gently shake the inoculated tubes of EC medium to insure adequate mixing
and incubate in a waterbath at 44.5 ±0.2 °C for 24 ±2 hours. Gas production of any amount in the inner fermentation
tube of the EC medium indicates a positive fecal colifoirm test.'The preparation of EC medium is described in the 18th
edition of Standard Methods for the Examination of Water and Wastewater, 1992, Method 9221E-p. 9-52, paragraph la.
Public water systems need only determine the presence or absence of fecal coliforms; a determination of fecal coliform
density is not required.
(6) Public water systems must conduct analysis of Escherichia coli in accordance with one of the following analytical
methods:
© EC medium supplemented with 50 jig/mL of 4-methylumbeUiferyl-beta-D-glucuronide (MUG) (final concentration).
EC medium is described in the 18th edition of Standard Methods for the Examination of Water and Wastewater, 1992,
Method 9221E-p. 9-52, paragraph la. MUG may be added to EC medium before autoclaving. EC medium supplemented
with 50 /ig/mL of MUG is commercially available. At least 10 mL of EC medium supplemented with MUG must be used.
The inner inverted fermentation tube may be omitted. The procedure for transferring a total coliform-positive culture to
EC medium supplemented with MUG shall be as specified in paragraph (f)(5) of this section for transferring a total
coliform-positive culture to EC medium. Observe fluorescence with an ultraviolet light (366 nm) in the dark after
incubating tubes at 44.5 ±0.2 °C for 24 ±2 hours; or
00 Nutrient agar supplemented with 100 jug/mL 4-methylumbemferyl-beta-D-glucuronide (MUG) (final concentration).
Nutrient Agar is described in the 18th edition of Standard Methods for the Examination of Water and Wastewater, 1992,
p. 947 to 9-48. This test is used to determine if a total coliform-positive sample, as determined by the Membrane Filter
Technique or any other method in which a membrane filter is used,, contains E. coJi. Transfer the membrane filter
containing a total coliform colony(ies) to nutrient agar supplemented with 100 /ig/mL (final concentration) of MUG. After
incubating the agar plate at 35 °C for 4 hours, observe the colony(ies) under ultraviolet light (366 nm) in the dark for
fluorescence. If fluorescence is visible, E. coli are present.
(iii) Minimal Medium ONPG-MUG (MMO-MUG) Test, as set forth in the article "National Field Evaluation of a
Defined Substrate Method for the Simultaneous Detection of Total Conforms and F.sc,herichia coJi from Drinking Water:
Comparison with Presence-Absence Techniques" (Edberg et al.), Applied and Environmental Microbiology, Volume 55,
pp. 1003-1008, April 1989. (Note: The Autoanalysis Colilert System is an MMO-MUG test). If the MMO-MUG test is
total coliform-positive after a 24-hour incubation, test the medium for fluorescence with a 366-nm ultraviolet light
(preferably with a 6-watt lamp) in the dark. If fluorescence is observed, the sample is E. coli-positive. If fluorescence is
questionable (cannot be definitively read) after 24 hours incubation, incubate the culture for an additional four hours (but
not to exceed 28 hours total), and again test the medium
for fluorescence. The MMO-MUG Test with hepes buffer in lieu of phosphate buffer is the only approved formulation
for the detection of E. coli. •
(iv) The Colisure Test. A description of the Colisure Test -4-may be obtained from the Mulipore Corporation, Technical
Services Department, 80 Ashby Road, Bedford, MA 01730.
(7) As an option to paragraph (f)(6)(iii) of this section, a system with a total coliform-positive, MUG-negative,
MMO-MUG test may further analyze the culture for the presence of E. coli by transferring a 0.1 mL, 28-hour
MMO-MUG culture to EC Medium + MUG with a pipet. The formulation and incubation conditions of EC Medium +
MUG, and observation of the results are described in paragraph (f)(6)(i) of this section.
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2. Surface Water Treatment Rule (40 CFR 141.74(a))
(a) Analytical requirements. Only the analytical method(s) specified in this paragraph, or otherwise approved by
EPA, may be used to demonstrate compliance with the requirements of § 141.71, 141.72, and 141.73. Measurements
for pH, temperature, turbidity, and residual disinfectant concentrations must be conducted by a party approved by the
State. Measurements for total conforms, fecal coliforms, and HPC must be conducted by a laboratory certified by the
State or EPA to do such analysis. Until laboratory certification criteria are developed for the analysis of HPC and fecal
coliforms, any laboratory certified for total coliform analysis by EPA is deemed certified for HPC and fecal coliform
analysis. The following procedures will be performed in accordance with the publications listed in the following section.
This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a)
and 1 CFR part 51. Copies of the methods published in Standard Methods for the Examination of Water and Wastewater
may be obtained from the American Public Health Association et al., 1015 Fifteenth Street, NW, Washington, D.C.
20005; copies of the Minimal Medium ONPG-MUG Method as set forth in the article "National Field Evaluation of a
Defined Substrate Method for the Simultaneous Enumeration of Total Coliforms and Escherichia coli from Drinking
Water: Comparison with the Standard Multiple Tube Fermentation Method" (Edberg et al.), Applied and Environmental
Microbiology, Volume 54, pp. 1595-1601, June 1988 (as amended under Erratum, Applied and Environmental
Microbiology, Volume 54, p. 3197, December 1988), may be obtained'from the American Water Works Association
Research Foundation, 6666 West Quincy Avenue, Denver, Colorado, 80235; and copies of the Indigo Method as set forth
in the article "Determination of Ozone in Water by the Indigo Method" (Bader and Hoigne), may be obtained from Ozone
Science & Engineering, Pergamon Press Ltd., Fairview Park, Elmsford, New York 10523. Copies may be inspected
at the U.S. Environmental Protection Agency, Room EB15, 401 M Street, SW., Washington, D.C. 20460 or at the Office
of the Federal Register, 1100 L Street, NW, Room 8401, Washington, D.C.
(1) Public water systems must conduct analysis of pH and temperature in accordance with one of the methods listed
at §141.23(k)(l). Public water systems must conduct analysis of total coliforms, fecal coliforms, heterotrophic bacteria,
and turbidity in accordance with one of the following analytical methods and by using analytical test procedures contained
in Technical Notes on Drinking Water Methods, EPA-600/R-94-173, October 1994, which is available at NTIS
PB95-104766.
Organism
Total Coliforms2
Fecal Coliforms2
Heterotrophic bacteria2
Turbidity
Methodology
Total Conform Fermentation Technique3'4'5
Total Coliform Membrane Filter Technique
ONPG-MUG Test6
Fecal Coliform Procedure7
Fecal Coliform Membrane Filter Procedure
Pour Plate Method
Nephelometric Method
Nephelometric Method
Great Lakes Instruments
Citation1
9221A,B,C
9222A,B,C
9223
9221E
9221D
9215B
2130B
180. 18
Method 29
1 Except where noted, all methods refer to the 18th edition of Standard Methods for the Examination of Water and
Wastewater, 1992, American Public Health Association, 1015 Fifteenth Street NW, Washington, D.C. 20005.
2 The time from sample collection to initiation of analysis may not exceed 8 hours. Systems are encouraged but not
required to hold samples below 10°C during transit.
3 Lactose broth, as commercially available, may be used in lieu of lauryl tryptose broth, if the system conducts at
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least 25 parallel tests between this medium and lauryl tryptose broth using the water normally tested, and this
comparison demonstrates that the false positive rate and false negative rate for total conforms, using lactose broth,
are less than 10 percent. ;
4 Media should cover inverted tubes at least one-half to two-thirds after the sample is added.
5 No requirement exists to run the completed phase on 10 percent of all total couform-positive confirmed tubes.
6 The ONPG-MUG Test is also known as the Autoanalysis Cqlilert System.
7 A-l Broth may be held up to three months in a tightly closed screwcap tube at 4°C.
8 "Methods for the Determination of Inorganic Substances in Environmental Samples," EPA-600/R-93-100, August
1993. Available at NTIS, PB94-12I811. : .
9 GLI Method 2, "Turbidity," November 2, 1992, Great Lakes Instruments, Inc., 8855 North 55th Street,
Milwaukee, Wisconsin 53223. ,
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Appendix H
Record Audits for Drinking Water Laboratories
Introduction
This Appendix provides information on the records which drinking water laboratories should maintain. It is intended to
assist the certification officer in conducting data audits for drinking water laboratories. Certification officers should use
the criteria in this Appendix, as well as appropriate earlier chapters, for evaluating all laboratories. Evaluation of
adequate record keeping/documentation can be facilitated by using the checklists (Chemistry, Microbiology, and
Radiochemistry) at the end of this Appendix. Auditors are encouraged to develop their own more comprehensive
checklists, using these as a starting point. The data audit information in the microbiology checklists (pp. H-21 to H-24)
is also included in Chapter 5. The Chapter 5 checklist supersedes this checklist which is included here only for appendix
completeness.
Implementing the recommended record keeping/documentation specified in this appendix will facilitate an "audit of data
quality," the tracking of one or more data points from sample receipt by the laboratory (or from sample collection and
preservation, if conducted by the laboratory), through preparation, analysis, interpretation, calculations, recording, and
reporting of results. All necessary documentation in laboratory records for each step in the data generation process
pertaining to any data point should be readily available for the auditor. By tracking this information, the auditor can better
assess the quality of data routinely generated by the laboratory.
If any criterion in this Appendix differs from a criterion in a specific EPA-approved method, the method takes precedence,
because its use is required by regulations.
Data Audits
The EPA Quality Assurance Glossary and Acronyms (February 1991) defines an audit of data quality as:
"A quantitative and qualitative evaluation of the documentation and procedures associated with environmental
measurements to verify that the resulting data are of acceptable quality."
The data audit is typically performed on-site and involves tracing the paper and electronic trail of an individual sample
or samples from the time of sample collection to the preparation of the final report. Auditors should be competent
scientists who are familiar with methodology, the particular data collection technology and QC procedures.
When a data audit is to be performed, the first step is to read the pertinent standard operating procedures (SOPs), and
generate a checklist of items to be examined. Procedures should be verified for sample collection, receipt, storage,
preparation, analysis, reporting, and all associated QC.
A checklist should be prepared prior to the on-site visit. When the on-site audit takes place, the sample or samples to
be examined should be chosen at random. One of the samples audited should be the most recent PE sample. Sample log-
in records, laboratory notebooks, extraction records, analysis records and any other documents necessary to confirm that
procedures were followed as described, should be examined.
The audit report should cite deficiencies, if any, in the procedures and/or documentation and suggested corrective actions.
The data audit process involves reviewing all records that document the sampling, storage and data generation processes
from beginning to end. Individual laboratories may use a variety of systems for recording, reporting, and storing such
information - including both manual and automated techniques. In addition, the specific information recorded by
laboratories may differ based on standard operating procedures and information storage and retrieval systems. The
auditor should be able to reconstruct the final reported data for a field or performance evaluation sample. A comparison
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of raw PE data to raw data for standards should verify that the laboratory has analyzed the PE sample at the correct
dilution.
Records to be Reviewed
This Appendix describes documentation needed to document the sampling, storage and data generation processes. These
items constitute the minimum suite of records that should comprise a comprehensive laboratory record keeping system.
Not all records apply to all types of drinking water analyses and the specific records needed at a laboratory will depend
on the analyses the laboratory runs. Records of laboratory analyses will vary with the method and instrumentation used.
For example, calibration records will be more detailed for instruments used in organic and inorganic chemical analyses
than for microbiological analyses. Field sampling and data recording and reporting records apply to all analyses.
The laboratory should record all information on individual data sheets or in a log book using ink. Original entries should
not be obliterated. Corrections should be made with a single line through the entry, initialed and dated. All records
maintained electronically should be secured to prevent unauthorized changes. If the laboratory changes to a new
system, all records should either be transferred to the Hew system or saved in hard copy format. All records should
be archived in an organized manner that allows easy retrieval. The ease with which laboratory managers are able to
retrieve data generation records may be the auditor's first indication of the completeness and effectiveness of the
laboratory data generation and record keeping system. Record keeping systems should allow correlation between system
and laboratory identification codes.
If a laboratory uses a subcontract laboratory for certain analyses, data provided by subcontract laboratories should be
clearly identified as such and any needed documentation at the subcontract laboratory should be available to the auditor
upon request.
Drinking water compliance data pertaining to chemical and radiological analyses must be stored and retained by the utility
for a period of ten years as required by 40 CFR 141.33. Data pertaining to microbiological analyses must be retained
for five years. Data for lead and copper (CFR 141.91) must be maintained for 12 years. It is recommended that the
laboratory maintain the compliance sample and QC data for at least five years or until the next audit, whichever is longer.
See Chapters IV, V, and VI, Section 8.2. Data should be stored in a manner that allows efficient and accurate retrieval.
The auditor should review the data storage and retrieval system carefully to determine whether proper procedures are
followed. If a laboratory is unable to locate data requested by the auditor or requires an inordinate period of time to
retrieve requested data, the auditor should consider the data storage system deficient.
To assist auditors in conducting data and record keeping audits, a series of checklists has been developed and are included
at the end of this Appendix. These checklists include specific items which should be checked during the data audit of an
individual field or PE sample.
1.0 Field Sampling
1.1 Sampling Records
At the time of sample collection, field personnel should record the information listed in the Sample Checklist (page. H-13,
Field Sampling) on a sample tracking form or electronically for each sample.
A sample tracking record should be maintained for samples. This record should be made in indelible ink or electronic
form and should identify the sample collector, the person or persons transporting the samples from the system to the
laboratory, as well as the individuals) who received the samples and the condition of the sample upon receipt. If a
commercial shipper was used, shipping records should be available.
Sample collection (and related data recording and record keeping) may not be within the scope of the laboratory's
responsibilities. Some field records therefore may not be available to or maintained by the laboratory. Either the
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laboratory or the organization responsible for sample collection should keep records describing how the sample containers
were prepared (i.e., cleaning methods, sterilization technique/date/time/batch number) and how preservatives were
prepared and how the samples were collected. In all cases, the sample tracking record and shipping form (if available)
should accompany samples to the laboratory, and this documentation, at a minimum, should be maintained by the
laboratory. Documentation should be available to verify that SOPs were used for sample collection and that the sample
collectors were properly trained.
1.2 Field Analytical Records
Field measurements made for parameters that are dynamic should be made immediately. If a laboratory conducts analyses
in the field (i.e., temperature, free residual chlorine, and pH), field personnel should record the items listed in the Sample
Checklist on page H-13, Field Measurements. Calibrations should be performed in the field over a range of
concentrations that bracket the concentrations measured in the unknown samples. For chemical analyses, the lowest
concentration used in a calibration should be at least as low as the pertinent regulatory level. Thermometers should be
calibrated annually using a reference thermometer traceable to the National Institute of Standards and Technology.
Residual free chlorine comparison devices such as color wheels and their application by field personnel should be checked
semiannually. Procedures for field calibrations of instruments should be documented in standard operating procedures
for field activities.
1.3 Sample Inspection and Acceptance Policy
When samples arrive at the laboratory, whether by mail or other carrier, the laboratory should check samples and sample
records to verify that the required preservation steps and holding times have been adhered to. Laboratory personnel
should check sample and shipping containers for integrity (e.g., leaks, cracks, broken seals) and for any obvious signs
of improper collection (e.g., head space in VOC samples). The laboratory should verify that proper shipping procedures
were followed (e.g., ice should still be present with samples collected for organic analyses). This information should be
recorded. In larger laboratories, sample custodians should be designated to perform this function and automated
laboratory sample tracking systems may be used to record sample receipt and destination. When a bar code is, used, the
laboratory should calibrate the bar code reader periodically and document the calibration. ,
The laboratory should add the bullet items in the Sample Checklist (page H-14, Sample Acceptance) to the sample tracking
form for each sample at the time of receipt:
1.4 Sample Storage
The auditor should visit the sample receiving area of the laboratory and inspect the condition of samples to determine
that container labels are properly completed and securely attached and that all necessary information is recorded by the
laboratory. The auditor should also verify that samples requiring special handling (e.g., light sensitive, temperature
sensitive, radioactive) are properly stored and that samples are analyzed within their holding times.
Before analysis, the analyst should check samples for the proper preservation technique, pH, chlorine residual, etc.
Errors in sample preservation and/or handling are known to bias analytical results. Laboratories must reject compliance
samples which do not comply with the method sampling and preservation requirements and request a replacement sample.
2.0 Laboratory Analysis
2.1 Analytical Methods
Each laboratory should list and have on hand, in its Quality Assurance Plan, the SOPs (which include the analytical
method) for each drinking water analyte measured. This listing should include the name of the method and a complete
reference or source (e.g., 18th Edition of Standard Methods for Examination of Water and Wastewater, with method
number). The auditor should verify that the methods listed are EPA-approved for drinking water (or otherwise acceptable
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to EPA), that a copy of the method is available to the analyst, and that the methods listed are the only ones actually being
used for the analysis of the drinking water compliance samples.
Laboratories should have written SOPs for all analyses and laboratory procedures. The SOPs delineate the specific
procedures used to carry out the methods and how, if at all, the SOP differs from the required method. The purpose of
the SOPs is to specify analytical procedures in greater detail than appears in the published method in order to further
ensure that analyses are conducted in a standard manner by all analysts in a laboratory. The auditor should verify that
analysts are following the written SOPs and that the SOPs are consistent with EPA approved analytical methods for
drinking water and any deviations are clearly identified. The SOPs should be available in the laboratory at the analyst's
work station.
2.2 Instrument Performance
Instrument and equipment performance is a significant factor in laboratory data quality. Consequently, the laboratory
should monitor and document instrument/equipment performance characteristics regularly, in accordance with method
specifications and the recommendations of equipment manufacturers. For all instruments/equipment, the bullet items
in the Checklist (page H-15, Instrument Performance) should be maintained (insofar as they apply to analyses conducted
by the laboratory).
Performance records are important for all instruments and equipment used to perform drinking water analyses, including
analytical balances, incubators, refrigerators, autoclaves, water baths, and block digesters. For such equipment, routine
calibrations against standards traceable to the National Institute of Standards and Technology (MIST) should be performed.
ASTM type 1 or 2 weights or better should be available to make daily checks on balances. A record of these checks
should be available for inspection. The specific checks and their frequency should be as prescribed in the laboratory's
QA plan and the laboratory's operations manual, if appropriate. The ASTM weights should be recertified annually.
Wavelengths on spectrophotometers should be verified daily with color standards. A record of these checks should be
available for inspection. The specific checks and their frequency should be as prescribed in the laboratory's SOPs.
Proper maintenance of all laboratory instruments/equipment is critical to achieving proper laboratory performance.
Instrument manufacturers provide suggested maintenance schedules and laboratories should adhere to such schedules.
Laboratories should also record maintenance and repair activities for all instruments, including both determinative
instruments (e.g., specific ion detectors, spectrophotometers, etc.) and non-determinative equipment (e.g., incubators,
ovens, balances, etc.). Maintenance logs should also list the maintenance schedule and the date and name of the
individuals) performing routine instrument maintenance.
2.3 Initial Demonstration of Capability
The initial demonstration of capability (EDC) ensures that the analyst and the method are capable of measuring the analytes
of interest within the acceptance criteria necessary to comply with the regulations. The IDC should be performed for each
analyst and instrument used before compliance samples are analyzed. The variability introduced by multiple sample
preparation technicians must also be taken into account. The typical IDC for chemical measurements consists of
demonstrating proficiency in four areas: precision, accuracy (bias), method blank background, and method detection
limit. For microbiological methods, the specificity, relative trueness, positive and negative deviation and repeatability
should be estimated if possible. This should include a replicate demonstration of negative results on appropriate negative
controls and positive results and confirmations on appropriate positive controls. When reviewing the documentation, the
auditor should verify that all results, including errors, are reported in the correct units. Laboratories should also record
any actions taken to correct performance that does not fall within the acceptable range established by the applicable
method. The method detection limits (MDLs) must be calculated in accordance with 40 CFR 136, Appendix B. .The
qualitative confirmation capability should be determined ascertaining the detection limits for alternate techniques. When
unacceptable performance occurs on QC samples, compliance samples should be reanalyzed after acceptable performance
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has been established.
Laboratories should maintain complete records for the IDC which include the bullet items in the Checklist on page H-16,
Initial Demonstration of Capability.
2.3.1 Method Precision and Bias
Method precision and bias measurements should be made for chemical analyses each time an analytical method is used
and periodically, as specified in Chapter V, for microbiological contaminants. Precision is calculated using repeated
measurements. Bias measurements are made by spiking samples or reagent water with known concentrations of analytes
or suspensions of microorganisms, and measuring the resulting percent recovery. Laboratories should develop standard
operating procedures for this purpose that are consistent with the quality control requirements specified in Chapters IV,
V and VI of this Manual, unless otherwise specified in the published method.
For microbiology, the laboratory should analyze duplicate positive samples and take part in proficiency testing or inter
laboratory comparisons.
For radiochemistry, precision and accuracy are determined from a laboratory fortified sample matrix (spike) with each
batch of samples. Samples should be fortified at 1-10 times the MCL or 5-10 times the background.
Laboratories should maintain complete records of method precision and bias, consistent with the specifications of
published methods or, if none are included in the method, consistent with stated laboratory standard operating procedures.
Method precision and bias records should include the source, preparation date, and concentration^) of standards used.
These records should be reviewed by the auditor to verify that the limits of precision and bias achieved are consistent with
those established in the published method. If measured precision and bias do not fall within acceptable ranges, efforts
should be made to ascertain the reason(s) and depending on the nature of the problem, samples may need to be reanalyzed.
The laboratory should also record the reason, identify and implement an appropriate corrective action, and document the
results of the corrective action.
2.3.2 Demonstration of Low System Background
For chemistry, most EPA methods require the analysis of a reagent blank with each batch of samples to measure the
contamination which may be introduced at the laboratory, hi general, the value of the reagent blank should not exceed
the MDL. If the blank exceeds the MDL, samples should be reanalyzed after the contamination has been found and the
problem corrected.
For microbiology, the laboratory should analyze negative controls to demonstrate that the cultured samples have not been
contaminated.
For radiochemistry, blanks are used to determine if activity is added to the sample from the reagents. Typically, the
background is the instrument background which is subtracted from all sample counts.
2.3.3 Analytical Method Detection Limit for Chemical and Radiochemical Analyses
The method detection limit (MDL) is the minimum concentration of analyte that can be measured and reported with 99%
confidence that the analyte concentration is greater than zero.
Laboratories should determine their own method detection limits for all organic, inorganic and radiochemistry methods
using the procedure in 40 CFR 136 Appendix B. Each analytical team using a particular analytical method also should
determine it's own detection limits. In addition, if several different instruments are used for the same procedure, then
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the detection limit should be determined for each instrument. The same extracts may be used to determine the detection
limits on several instruments with similar sensitivity, if. appropriate.
A procedure for measuring method detection limits is described in 40 CFR Part 136, Appendix B. This procedure
involves analyzing seven replicate water samples that have been spiked to, or are known to, contain the analyte at a
concentration at or near the estimated detection limit. Laboratories should maintain documentation for the bullet items
in the Checklist on page H-17, Method Detection Limits.
Although 40 CFR 136, Appendix B, provides several possible approaches to selecting an estimated detection limit for
purposes of designing the study, laboratory auditors should recognize that the most reliable method involves an iterative
process of measuring achievability of successively lower concentrations until the actual limit of detection is identified.
At a minimum, this approach should be used for purposes of establishing the working MDL when a new method is first
used by a laboratory. Successive detection limit determinations to verify the limit in the same matrix or establish the limit
in a new matrix may not require measurement of detect ability at numerous concentrations, depending on the experience
of the analyst. Any procedure that involves measurement of only one concentration should be reviewed carefully to
establish that the analyst was able to document that the concentration measured meets the definition of a method detection
limit. The spike concentration should be determined by the signal to noise ratio for each analyte. The same concentration
for all analytes will not produce acceptable results. The extractions/analyses should be performed over a period of at least
three days to provide a more reasonable MDL.
The required detection limits for Radionuclides are listed in the CFR. Detection limits for Radionuclides are determined
on the basis of nuclear counting statistics in addition to sample and instrument parameters. Proper counting errors should
be calculated for each method and reported with each sample analyses.
2.4 Instrument Calibration and Calibration Records
For all types of analytical instruments, it is important that the analyst establish the relationship between the measured
vahie and the concentration of the analyte in the sample, daily, using accurate reference materials. The calibration should
include at least three concentrations in the linear portion of the curve. Additional standards should be used if the curve
is nonlinear. The concentrations should be selected to bracket the range of concentrations expected to be observed in the
samples to be analyzed. Some organic methods recommend using five concentrations. Some inorganic methods require
a blank and three standard concentrations.
Calibration for some methods is very time-consuming. For these methods, the standard curve should be initially
developed and thereafter, at the beginning of each day on which analyses are performed, this curve should be verified
by analysis of at least one standard in the expected concentration range of the samples analyzed that day or within the
operating range. All checks must be within the control limits specified in the method or the system must be recalibrated.
For radiochemistry, efficiency (counts per minute per disintegration per minute) curves should be used to determine the
efficiency for a given mass or nuclide energy. For alpha and beta counters, the change in efficiency should be plotted
versus mass to determine the efficiency at a given mass. For gas flow proportional counters, sample composition, size,
alpha/beta energy and distance from the detector influence efficiency. For gamma counters, two curves should be
prepared, energy versus channel number and efficiency versus energy. For gamma counters, the primary variable is the
distance from the source to the detector. Each type of sample container will have a unique gamma efficiency curve. The
shape of the curve is intrinsic to the detector material and will be the same for each geometry subject to differences due
to distance. The Efficiency is constant for many orders of magnitude. Standards should be prepared at a level of activity
so that greater than 1600 counts above background are acquired during the counting time. Under this condition, the
uncertainty will be 5% (2SD) at the 95 % confidence level. To verify the curve, one or more of the standards should be
counted daily when samples are counted. The RSD should not exceed 3SD or 10% of the expected value. Multi term
polynomial curves should be generated from the relationship between efficiency and either mass or energy.
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Laboratory records should include the concentrations of standards used, a graph of the calibration curve and if possible
a description of statistical procedures used to establish the curve, the source of standard materials, date of preparation
and a description of standard preparation steps or reference to the SOP. To simplify these records, laboratories may
reference a Standard Operating Procedure which specifies the calibration procedures.
Quality control (QC) samples from an outside source should be used to verify all initial calibrations. Two or three QC
standard concentrations chosen to bracket the working range are recommended. For radiochemistry counting, the
laboratory should use a check source and a background both at the beginning and end of each batch of samples, especially
if the counter is not in constant use. Regardless of the number of samples analyzed, a record of a check standard analyzed
at the end of each batch should be maintained. In general, if the results of a check sample analysis at the end of a batch
exceed the confidence limits (CL) of the method, a system review and corrective action (such as recalibration) are
indicated and the samples should be re-analyzed. Laboratories may develop their own guidelines for determining when
re-analysis is necessary (where not specified in the method). Such guidelines should be statistically linked to method
performance (e.g., phis or minus one standard deviation). Where these guidelines are applied, the auditor should verify
that the basis for the guideline is recorded.
Many analysts believe that multiple standard concentrations need not be used to calibrate instruments that provide direct
concentration readings because manufacturers of the instruments specify the use of a single standard concentration for
calibration. For such instruments, multiple concentrations that bracket the required working range are strongly
recommended. These standards should be treated as samples and a record of the instrument readings should be
maintained by the analyst. A general rule of thumb is that the measured concentration should be within 10 percent of the
actual concentration.
Most methods specify calibration procedures and the auditor should verify that procedures are being followed by the
analysts and are consistent with those specified by the method. Where methods do not specify calibration requirements,
instrument manufacturers' recommendations or other guidance may be available.
2.5 Routine Monitoring of Analytical Method Performance
Laboratory Quality Assurance Plans should specify a reasonable schedule for routine monitoring of method performance
based on requirements specified in the approved EPA methods or based on requirements for other similar measurements
where the method does not specify a requirement. Most organic and radiological methods specify requirements for
periodic monitoring of method performance.
Methods for microbiological analyses require periodic duplicate analyses as a routine check on method performance.
Positive and negative controls should also be analyzed on a regular basis and whenever new media is prepared or
commercially prepared media is received.
Method performance documentation should include the bullet items listed in the Checklist (page H-19, Routine
Performance Checks). Further discussion of these records has been provided in the previous sections.
2.5.1 Laboratory Fortified Blanks
The laboratory should analyze a laboratory fortified blank (LFB) with each batch of samples analyzed. The concentration
of the LFB should be ten times the MDL or estimated detection level or equivalent to a mid range standard. At least some
portion of the LFBs should be at the laboratory's reporting level. Precision and recovery for the LFBs must be within
the criteria specified in the methods or the corrective action specified in the method must be taken. The LFBs must be
processed through the entire analytical procedure (e.g., extraction, derivation and detection).
Control charts or limits, generated from mean percent recovery and standard deviation of the laboratory fortified blanks,
should be maintained by the laboratory. Until sufficient data are available from the laboratory, usually a minimum of 20
to 30 test results on a specific analysis, the laboratory should use the control limits specified in the methods. See Standard
H-7
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Methods for tJie Examination of Water and Wastewater, part 1020B, or similar QC reference texts for further information.
The laboratory should continue to calculate control limits for each analyte as additional results become available. After
each five to ten new recovery measurements, new control limits should be calculated using the most recent 20-30 data
poults. If any of these control limits are tighter than the method specifications, the laboratory should use the tighter
criteria. Otherwise, control limits in the methods are required. Control charts are highly recommended even though some
of the older methods for inorganic analytes do not include such requirements.
For microbiology, a pure culture of a known positive reaction should be included with a sample batch periodically and
when new media is prepared, to demonstrate that the medium can support growth.
2.5.2 Laboratory Fortified Matrix
The laboratory should also fortify a minimum of 10% (or one per batch, whichever is greater) of the routine samples
(except when the method specifies a different percentage, e.g., furnace methods) to determine if there are any matrix
effects. The spike concentration should not be substantially less than the background concentration, of the sample selected
for spiking. If the sample concentration is below the MDL, then the analyst may choose appropriate spike levels (e.g.,
a percentage of the MCL or operating calibration range). This laboratory fortified matrix must be processed through
the entire analytical procedure. Over time, to the extent practical, samples from all routine sample sources should be
spiked. If any of these checks are not within the control limits specified; and the method was in control as judged by the
LFB, the results of that sample should be labeled suspect due to sample matrix.
2.5.3 Quality Control Samples
At least once each quarter, each laboratory should analyze quality control or reference samples from a source other than
that from which their standards are purchased (for each method, analyst, and instrument) as a routine check on
performance. If errors exceed limits specified in the methods, corrective action should be taken and documented, and
a follow-up quality control standard analyzed as soon as possible to demonstrate the problem has been corrected. The
laboratory should maintain records for these routine checks.
2.5.4 Blanks
Most of the EPA-approved analytical methods specify analysis of one or more blank samples with every batch of samples
analyzed. Follow the method recommendations and requirements. See the discussion of laboratory reagent blanks in
section 2.3.2. Laboratory reagent blanks (method blanks) measure the level of contamination that may be introduced at
the laboratory. The results of analyzing blank samples should be recorded by the analyst with all other data and checked
by the auditor.
Field blanks should also be analyzed to measure contamination which may be introduced from preservatives, storage or
at the sampling site. A field blank may be substituted for the reagent blank. However, if the field blank is contaminated,
then a reagent blank must be analyzed to determine the source of the contamination. Trip blanks may also be required
to determine if contamination occurred during shipping.
All blanks must be processed through the entire analytical procedure.
Most analytical methods specify an acceptable maximum level for the analyte in a blank sample. Some States require that
blank results indicating contamination be submitted with the analytical results.
2.5.5 Other Quality Control Requirements
Some methods require duplicate sample analyses, method of standard additions, column or instrument performance check
samples, instrument tuning checks, etc. Whenever additional quality control requirements are specified in the method
or method manual, they must be followed.
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2.5.6 Performance Evaluation Studies
In order to receive and maintain certification, drinking water laboratories must successfully analyze performance
evaluation (PE) samples, in accordance with the requirements in the NPDWR. In addition to these samples, laboratories
certified for radiochemical analysis must also participate in other performance evaluation studies each year as prescribed
by the program. Laboratories are required to maintain records of their performance in those studies and any corrective
actions taken in response to performance problems indicated by the study results. A copy of this documentation should
be forwarded to the certification officer. Auditors should review these records to determine that all errors or performance
problems are addressed and that proper corrective actions have been taken, where appropriate. Auditors should review
the raw PE data to verify that the PE samples were diluted according the instructions provided. The auditor should be
able to verify from the raw data (e.g., area counts for GC analysis) that the PE samples were analyzed with the correct
dilution factor.
2.6 Instrument Maintenance
Proper maintenance of all laboratory instruments and equipment is critical to achieving proper laboratory performance.
Instrument manufacturers provide suggested maintenance schedules and laboratories should adhere to such schedules.
Laboratories should also record maintenance and repair activities for all instruments.
3.0 Data Handling and Reporting
3.1 Calculations
During the data audit, the auditor should review all procedures for calculating final values from the raw data.
Laboratories should maintain written standard operating procedures for making all calculations, and all raw data and
supporting information needed to recreate the calculations should be available to the auditor. The auditor should verify
representative calculations sufficient to provide a reasonable level of confidence that the appropriate procedures are being
used consistently. Using the raw data, the auditor should be able to regenerate the sample data reported to the customer.
In cases where the laboratory does not provide documentation for calculation methods and the method used is not readily
apparent, the auditor should attempt to verify calculations using techniques normally used by the Regional or State
laboratory. If the results do not agree with those reported by the laboratory, the auditor should attempt to ascertain and
evaluate the calculation method used. This may require interviewing one or more analysts who routinely make the
calculations to determine the step-wise process used and to determine that ah1 analysts in the laboratory are using the same
method. To avoid calculation errors, laboratories should implement a policy of requiring that all calculations be cross-
checked by a second analyst. Both analysts should certify the data, by signature with date in ink, and note as acceptable
to document that the data has been cross-checked. Where possible, calculations should also be verified by a laboratory
supervisor.
3.2 Use of Significant Figures
Laboratories should observe conventions concerning proper use of significant figures in making calculations to avoid the
appearance that the data are more precise than the method allows. Conventions for the use of significant digits and proper
rounding of numbers are discussed in detail in the EPA publication: Analytical Quality Control in Water and Wastewater
Laboratories (EPA-600/4-79-019) and in Standard Methods for Examination of Water and Wastewater (Section 1050
B in the 18th Edition). As a rule, the significance of an analytical result cannot exceed the significance of the least precise
step in the procedure. The numbers resulting from calculations cannot reflect greater precision than the data used to make
the calculations, hi order to verify that proper conventions have been followed, the auditor should identify the least
precise step in the analytical process.
Frequently, the least precise step is the measurement of the sample volume necessary for the analysis, which most often
involves the use of a graduated cylinder or pipette. The auditor should verify the actual tolerances of glassware used in
the laboratory analytical methods (by examining the glassware) and determine that the appropriate number of significant
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digits has been carried through all data recording and calculations.
3.3 Reporting Greater-Than and Less-Than Values
Less-than values occur frequently in drinking water analysis. For chemical analytes, less-than values should be recorded
by the analyst when the measure obtained is below the value of the lowest standard used to generate the calibration curve.
These reported less-than values should be followed with the value of the lowest concentration used in the calibration curve
(e.g., <0.2). Regulations may require the laboratory to report data, either quantitatively or qualitatively, to the MDL.
If this situation exists, laboratories may report data as "detected" less than the lowest standard (e.g., detected <0.2).
If the method involves a one point calibration, values may be reported down to the MDL.
Samples with concentrations greater than the highest standard should be diluted to fall within the calibration curve. If
unusual circumstances prevent this, results should be reported as greater than the highest standard and another sample
should be obtained.
For microbiological contaminants, if the organism of concern is not detected, the analyst may report total and fecal
coliform and E. coli as absent and Heterotrophic Plate Count (HPC) as < 1 per unit volume. If the concentration is too
great, HPC should be reported as too numerous to count.
3.4 Blank corrections
Correction of sample data for blank results is an important issue in data reporting, hi general, analyte measurements in
the blank that exceed allowable levels should be interpreted as an indication of laboratory contamination or other
performance problem. Data should never be corrected for blank measurements unless specifically stated in the analytical
method being utilized. Laboratories should take steps to isolate and eliminate sources of contamination where blank
analyses indicate a consistent and significant problem.
3.5 Error types •
The auditor should ensure that the laboratory Quality Assurance Plan specifies safeguards for protecting against
common types of data errors. In general, procedures for spot-checking data and for verification by a second analyst are
the most common practices used. Some common types of data errors include the following:
Data entry errors;
Transcription errors;
Rounding errors;
. Calculation errors;
Failure to record or retain data, especially dilution factors;
Incomplete data reporting (i.e., missing quality control or method performance data);
Omission of units or incorrect units;
Improper data error corrections (a single line should be drawn through an incorrect value such that
both the correct and incorrect values are legible; change should be initialed and dated);
Recording data in pencil (data must be recorded in indelible ink to help ensure data integrity);
Errors in use of significant figures (see section 3.2);
Errors in logic (for example, applying a blank correction, where allowed by the method, at the
wrong step in the calculation);
For radiochemistry, other errors may occur if the following factors are not considered: yield determinations, decay
and/or ingrowth factors, use of proper counting times, and accurate efficiency curves.
Virtually all of these types of errors can be prevented by requiring that all data be checked and initialed and dated by a
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second analyst (and verified by a laboratory supervisor, if possible) before being recorded for final reporting.
3.6 General Quality Control Records
During the data audit, in addition to identifying and reviewing quality control data specific to individual analyses,
the auditor should verify that certain general quality control procedures are conducted and that written records or logs
are maintained regularly by the laboratory. For example:
The date on which chemicals arrive in the laboratory and the date that reagents are first opened
should be recorded on the bottle label and initialed by the analyst;
Reference standard calibration solutions should include labels that list the date of preparation, the
concentration, and the name of the analyst who prepared the standard;
Training records for laboratory analysts should include academic background, specialized training
courses completed, and chemical analysis and instrument experience;
Stock standard solution logs should list the preparation date, the concentration, and the name of the
analyst who prepared the solution and the dilution solvent;
GC injection logs should list each sample injected, the time and date of analysis, and the name of
the analyst who performed the analysis;
3.7 Data Security and Back-Up
Laboratories should maintain data in a secure system to which access is limited. A system for logging files in and out
should be maintained so that laboratory files are known to be complete at all times. An original copy of the data report
showing all corrections or changes should be maintained on file. Additional copies for use by analysts may also be
maintained and tracked. A laboratory manager should certify, in writing (or by using a unique code identifier for
electronic reporting), the authenticity of each data report, and maintain such certification records for inspection.
The trend to replace manual operations with computers is expanding rapidly and the data management practices used to
protect the integrity of electronic data are becoming increasingly important. Minimum records to be maintained include
a description of the hardware and software used; written SOPs that document procedures for generating, validating, and
reviewing computer data; and results of periodic in-house QC inspections of electronic data generation and reporting.
Any data stored electronically should be supported with backup files generated in accordance with Agency guidelines
specified in the EPA document, 2185 - Good Laboratory Practices for Automated Data, 1995 Edition (Office of
Information Resources Management, RTP, NC 27711). This guidance document suggests appropriate frequencies for
generating backup files and suggestions for off-site storage of copies. One important disadvantage of electronic formats
is that they are software and hardware dependent.
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DRINKING WATER CERTIFICATION
RECORD KEEPING AUDIT
SAMPLE CHECKLIST
Field Records
1.1 Fiejd Sampling
The following items should be recorded in ink at the time of sample collection as part of
the sample tracking record
• Sample identification number
• Public Water System ID number (where applicable)
• Date and time of sample collection
• Sample type (i.e., compliance, confirmation, etc.)
• Analyses required
• Sample container type and size, preservatives, holding time
• Sample volume or weight collected
• Name, phone number and organization of sampler
• Preservatives added to the sample, concentration and amount added
• Sampling location (site ID number, treatment information, where applicable)
• Sample shipping procedure and holding time
• Sample container preparation (i.e., cleaning methods, sterilization
technique/date/time/batch number)
• pH and disinfectant residual from plant measurements if available
1.2 Field Measurements"
Field analytical records include the following items:
• Sample identification number
• Date and time of each field measurement and time of sample collection
• Pertinent field data (i.e., temperature, free residual chlorine, and pH)
• Name of analyst
• A list of calibration steps and concentrations of standards
• Date of instrument calibration
• The type, concentration, preparation date and source of any calibration standards
used (e.g., reference buffers for pH and reference materials for disinfectant residual)
Yes
No
Comments
'
If performed by laboratory personnel H-13
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SAMPLE CHECKLIST
Laboratory Records
1.3 Sample Acceptance
Simple tracking records from field samplers are maintained for all samples
The following entries are added to the sample tracking form for all samples
• Name of the person delivering the sample
• Name of the person receiving the sample
• Date and time of sample collection and receipt
• Date and time of sample receipt
* Condition of samples received (i.e., sealed, unsealed, broken containers,
temperature, preservatives noted on label)
• Sample irregularities are documented at the time of sample receipt (i.e., improper
collection, shipping procedure not followed)
• New sample ID (if assigned by laboratory), which can be cross-referenced to the
original sample ID, methods, analysts assigned
Deficient samples are rejected in accordance with written laboratory policy
Sample rejection log is maintained
Maximum holding time not exceeded
Replacement sample requested for rejected sample
1.4 Sftmpte "Storage , - -
Samples are properly labeled and securely attached
Samples exceeding holding times are discarded
Volatiles are hermetically sealed :
Samples requiring special handling are properly stored (i.e., light sensitive, temperature
sensitive, radioactive)
Yes
No
Comments
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DRINKING WATER CERTIFICATION
DATA AUDIT
CHEMISTRY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
2.1 Analytical Methods
Analytical procedures (SOPs) are listed and referenced in the laboratory's Quality
Assurance (QA) Plan for all analytes measured and this listing accurately reflects the
analytical methods employed by the laboratory.
Only EPA-approved methods are used to analyze drinking water compliance samples
Method procedures are followed exactly by the laboratory personnel or allowed deviations
are listed in SOPs
Written Standard Operating Procedures (SOPs) are consistent with the approved methods
and are followed by the laboratory personnel
1.1 Instrument Performance
Laboratory monitors and documents instrument performance characteristics regularly, in
accordance with the method specifications and the equipment manufacturer's
recommendations
Instrument performance records are maintained and include the following items:
• Initial demonstration of capability
, • Determination of linear dynamic range
• Method Detection Limits ,
• Initial and routine instrument calibration
• Performance on standard reference materials and/or QC check samples
• Instrument sensitivity and stability
• Tuning checks
Laboratory equipment such as analytical balances and thermometers are calibrated against
standards traceable to MIST
Equipment stability records such as dry oven, incubator, refrigerator, autoclave, and
block digester temperatures are maintained
2.3 initial Demonstration of Capability
Method performance is demonstrated as specified by the published method
or if not specified,
A minimum of four replicates of a quality control or reference sample are processed
through all steps of the analytical procedure*
Method performance is validated for all analytes measured
Analytes are measured at levels within the required method performance range
Initial method precision and bias criteria are met
The method is validated for each analyst and each instrument the analyst uses
Variation due to multiple sample preparation technicians is taken into account
System background is below the MDL
MDLs are calculated for all analytes
Yes
No
Comments
.
* If no other requirements are specified by the published method.
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CHEMISTRY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
Qualitative capability is identified for each analyte
Method validation records are maintained and include the following items:
• Name and/or number of the analytical method
• Name of analyst
• The typo of test ;
• Date and time of analyses
• Instrument identification number
• Number of replicates analyzed
• Concentrations of the standards used
• A description of any standard preparation steps (preparation date, name of the analyst
who prepared the standard, and the reagents used)
• Source of the standard material and preparation date
• All calculations and supporting data
Calculated error is expressed in the same units as the reported data
Corrective action is documented and resulting performance is reported where method
performance is outside acceptable ranges
2.3.1 Method Precision and Bias
Method precision and bias measurements are conducted as specified by the published
method
or
Precision and bias measurements follow the standard operating procedures developed by
the laboratory*
Method precision and bias are determined for all analytes measured
Method precision and bias are determined at the correct frequency
Method precision and bias control limits are met for all analytes measured
Precision records are maintained for each instrument and include the following items:
• Name and/or number of the method
• Name of analyst
• Date and time of analyses
• The number of replicates analyzed
• All calculations and supporting data
A minimum of 10% of routine samples are spiked and analyzed (unless the method
specifies > different percentage)
Spiked sample records are maintained and include the following items:
• Name and/or number of the method
• Name of the analyst
• Date and time of analyses
• Spike amounts added to samples
Yes
No
Comments
* Where no requirements are specified by the published method
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CHEMISTRY LABORATORY ANALYSIS REVIEW CHECKLIST
• Laboratory Records
• Concentration of the check standard used
• Source of the standard material
• A description of any standard preparation steps (preparation date, name of the analyst
who prepared the standard, and reagents used)
• All calculations and supporting data _ .. , .
Quality Control charts (% recovery vs time) are maintained or QC limits calculated
Corrective action is documented and re-analysis results are reported where precision and
bias limits fall outside acceptable ranges
2,3.2 Method DeteetioaLfaHlte
Method detection limits (MDLs) are measured for all analytical methods
Each analyst measures their own detection limit for each analytical method and instrument
used in the procedure
MDLs are determined by the procedure described in 40 CFR Part 136
Appendix 6
MDL records are maintained and include the following items:
• Name and/or number of the method
• Date of sampling and date of analyses
• Identification of the analyst
• .The MDL achieved and the method's published MDL (in appropriate units)
•, Analyte level spiked or in the sample . -
• Number of replicates analyzed
• A description of any allowable-variations used in the method
• A description of the type of water in which the MDL is measured
• A description of the procedure used to determine the MDL(iterative process used?)
and a description of the process used to estimate the MDL
• Analyte recovery values of reference materials or spiked samples
• All raw data and calculations necessary to reconstruct MDL determination
2.4 Initial Instrument Cafibratkm -—»• - -
Initial calibration is conducted as specified by the published method
or ,
Three or more concentrations should be analyzed. The lowest calibration standard
measured should be near the reporting level, and the remaining concentrations bracket
analyte levels* .,......,.
Instruments are calibrated for all analytes measured
Standard calibration materials are from a different source than the QC standards
Analytes are measured at concentrations covering the sample concentration range
Instruments are calibrated at the correct frequency as specified by the method
and/or the instrument manufacturer's recommendations
Yes
No
Comments
•- .
,
* Where no requirements are specified by the published method
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CHEMISTRY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
Calibration records are maintained for each instrument and include the following items:
• Name and/or number of the analytical method
• Date and time of calibration measurements
• Name of the analyst
• Concentrations of the standards used
• A description of any standard preparation steps (preparation date, the name of the
analyst who prepared the standard, and reagents used)
• Source of the standard material
• Labeled graph of the calibration curve
• A description of any statistical procedures used to establish the curve
• All calculations and supporting data
Instrument sensitivity (calibration curve slope) is documented
Continuing Instrument Calibration , ~ ~ \ "'''i
Calibration check standards are routinely measured as specified by the published method
or
One or more check standards chosen to bracket analyte concentrations are measured each
working day, and a mid-point calibration standard is measured after each batch*
Instrument response is checked for all analytes measured at the required frequency
Analytcs arc measured at concentrations appropriate for the sample concentration
range
Calibration check standards are analyzed at the correct frequency as specified by
the method or the Manual for Certification of Laboratories Analyzing Drinking
Water
Calibration curves are verified for all analytes measured
Routine calibration records are maintained for each instrument and include the following
items:
• Name and/or number of the analytical method
• Date and time of check standard measurements
• Name of the analyst
• Concentration of check standards used
* Source of standard materials
• A description of any standard preparation steps
• All calculations and supporting data
Calibration procedures are consistent with those specified in the methods and are followed
by laboratory analysts
Corrective action (recalibration) is documented and re-analysis results are recorded where
check standard results do not meet method criteria
Written guidelines for recalibration and re-analysis are available*
Yes
No
Comments
! ' - '
* Where no requirements are specified by the published method
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CHEMISTRY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
&$ goBtfoe perfoimaace checks
Quality control (QC) or referenced materials are analyzed quarterly or as specified by the
published method • • *
LFBs are analyzed for all analytes measured at the required concentration
LFBs are analyzed at the correct .frequency
Method bias (% recovery) criteria is met for all analytes measured
QC or reference check samples are routinely analyzed for each method, analyst, and
instrument
Performance check records are maintained and include the following items:
• Name and/or number of the analytical method
• Name of the analyst
• The type of test
.• Date of analysis. , .
• Concentration of the standard used
• A description of any standard preparation steps (preparation date, the name of the
analyst who prepared the standard, and reagents used)
• Source of the standard material
• Method precision and bias . .. . .
• QC sample results
• PE sample results
• Matrix spike results
• All calculations and supporting data
2.5.1 Laboratory Performance Evaluation
The laboratory analyzes, at least annually, water supply performance evaluation samples
• within EPA limits
Performance evaluation study records are maintained
Corrective action is documented where performance problems are indicated by the study
results
2,6 " Jostnanent Maintenance
Instrument maintenance schedules from manufacturers are followed and maintenance
activities are documented
Repair activities are recorded for all instruments
Yes
No
Comments
- • .
* Where no requirements are specified by the published method
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DRINKING WATER CERTIFICATION
DATA AUDIT
(The data audit information in this checklist is also included hi Chapter 5. Microbiology laboratories do not have to refer to this
checklist. The Chapter 5 checklist superseeds this checklist which is included only for Appendix completeness.)
MICROBIOLOGY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
Laboratory Equipment, Supplies, add Materials
pH Meter
Commercial buffer solutions are dated when received and discarded before expiration
date
pH meter is standardized each use period with pH 7.0 and eithr 4.0 buffers or 10.0
buffer
pH buffer solutions not reused to calibrate pH meter
Balance
Balance is calibrated monthly using ASTM type 1 or 2 weights. If non-reference
weights are used, non-reference weights are calibrated using type 1 or 2 reference
weights
Correction data available with type I or 2 weights
Annual service contract or internal maintenance protocol and records maintained
Temperature Monitoring Device
Glass or electronic thermometers are checked annually and dial thermometers checked
quarterly at the temperature used against a reference NIST thermometer or one meeting
the requirements of MIST Monograph SP 250-23
Continuous recording devices used to monitor incubator temperature are recalibrated
annually against a NIST thermometer or one meeting the requirements of NIST
Monograph SP 250-23
Incubator
Temperature is recorded twice daily for days in use, with reading separated by a least
four hours
Autoclaves
Date, contents, sterilization time, and temperature are recorded for each cycle
Service contract or maintenance protocol is established
Heat sensitive tape, spore strips or ampules, or maximum temperature registering
thermometer are used during each autoclave cycle
Automatic timing mechanism is checked for accuracy with a stop watch
Hot air ovens
Date, sterilization time, and temperature are recorded for each cycle
Conductivity meter
Conductivity meter is calibrated monthly with a 0.01 M KC1 solution or lower
concentration
Yes
No
Comments
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MICROBIOLOGY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
Refrigerator
Temperature is recorded for days in use
Membrane filters and pads
Lot numbers of membrane filters and the date received are recorded
Sterility is determined of each lot of membrane filters by placing one membrane filter
in non-selective broth medium
Ultraviolet lamp
Lamp used for sanitization is tested every quarter
Oteaend Laboratory Practices
Sample containers
Sterility of each lot of sample bottles or pre sterilized sample bags is determined by
adding non-selective broth, incubating at 35 °C for 24 hours and checking for growth
Reagent water
Reagent water is tested to assure the minimum requirements are met (see the Manual
for the Certification of Laboratories Analyzing Drinking Water, Chapter V, section
4.3.2, for parameter values and test frequencies)
Dilution/rinse water
pH of stock phosphate buffer solution is 7.2 ±0.2
pH of peptone water is 6.8 ±0.2
Dilution water is checked for sterility
Glassware washing
Inhibitory residue test is performed on clean glassware
Analytical media
Media preparation records include:
- Date of preparation
- Type of medium
- Lot number
- Sterilization time and temperature
- Final pH
- Technician's initials
Yes
No
Comments
i
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MICROBIOLOGY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
For liquid media prepared commercially, the following are recorded:
- Date received
- Type of medium
- Lot number
-pH verification
Each commercial lot of medium and each batch of laboratory prepared medium is checked
before use with positive and negative culture controls, and results recorded
EC medium + MUG (for E. coli)
Each lot of commercially prepared medium, or batch of laboratory-prepared medium,
is checked with positive and negative culture controls, and results recorded
Nutrient Agar Medium + MUG (for E. coli)
Quality of medium lot/batch is evaluated by spot-inoculating control bacteria
Performance evaluation sample is satisfactorily analyzed annually (if available)
- Analytical Methtxiotogy
A coliform test is conducted quarterly on known coliform-positive and fecal- or E. coli-
positive sample
Duplicate analyses are performed on 5% of samples2
Membrane filter technique (for total coliform in drinking water)
Sterility check is conducted on each funnel in use at the beginning and end of each
filtration series. If control indicates contamination, all data is rejected and another
sample obtained
EC Medium + MUG Test (for E. coli)
At least 5% of both MUG-positive results and turbid MUG-negative results are
verified for E. coli by the use of a multi-test system (API 20E or equivalent); standard
biochemical tests (e.g., citrate, indole, and urease tests); serotyping after biochemical
identification; or the indole test at 44.5°C and growth in citrate
Yes
No
Comments
2 Standard Methods for the Examination of Water and Wastewater, 18th Ed., 9020
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MICROBIOLOGY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
MF procedure (for total coliform in source water)
Sterility check is conducted on each funnel in use at the beginning and end of each
filtration series. If control indicates contamination, all data is rejected and another
sample obtained
If two or more analysts are available, each counts the total coliform colonies on same
membrane at least monthly. Colony counts agree within 10%
Multiple tube fermentation technique (for total coliform in source water)
Completed test is performed quarterly on coliform-positive tube(s)/bottles
Fecal coliform membrane filter procedure (for fecal coliform in source water)
Sterility check is conducted at beginning and end of each filtration series. If control
indicates contamination, data rejected and another sample obtained
If two or more analysts are available, each counts the total coliform colonies on same
membrane at least monthly. Colony counts agree within 10%
Date and start time are recorded for each analysis
Yes
No
Comments
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DRINKING WATER CERTIFICATION
DATA AUDIT
RADIOCHEMISTRY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
Analytical Methods
Analytical procedures are listed and referenced in the laboratory's Quality Assurance (QA)
plan for all analytes measured and this listing accurately reflects the analytical methods
employed by the laboratory.
Only EPA-approved methods are used to measure radioactivity in drinking water
Published methods are followed exactly by the laboratory personnel
Written Standard Operating Procedures (SOPs) are consistent with the approved methods and
are followed by the laboratory personnel
Initial Demonstration of Capability
Initial Instrument Calibration
Initial instrument calibration is conducted as specified by the published method
or
A background sample and one or more standard materials are analyzed at a minimum of 3
different concentrations.
All radionuclides are calibrated against standards traceable to NIST
Standards are measured at concentrations covering the sample concentration range
Instruments are calibrated at the correct frequency as specified by the method and/or
the instrument manufacturer's recommendations
Calibration standards are reported with the analytical results3
The following items are recorded for the standard material used for each radionuclide
analyzed4: .
A description of the solution (i.e., the principal radionuclide, mass or volume, and
chemical composition)
The reference time and date
The measurement result (activity of the principal and possible daughter
radionuclides/liter of solution)
The measurement method
Yes
No
Comments
: , . . -, ._, , . - - -
- - .
3 Standard Methods for the Examination of Water and Wastewater, 16th Ed., 1985
4 Handbook for Analytical Quality Control in Radioanalytical Laboratories, EPA/600/7-
77/088, pg. 4-2
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RADIOCHEMISTRY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
A statement of purity (a list of known impurities, their activities, and how they are
measured)
Decay information
An estimate of errors (from the measurement themselves and those created by the
decay assumption)
Calibration records are maintained for each instrument and include the following items:
• The name and/or number of the analytical method
• Name of the analyst
• Date and time, of analyses
• Source of the standard material
• A description of any standard preparation steps (preparation date, name of the analyst who
prepared the standard, and reagents used)
• Counting times
• Concentrations of the standards used
• A labeled graph of the calibration curve
• A description of any statistical procedures used to establish the curve
• All calculations and supporting data
Continuitig Instrument Calibration
A background sample and counting check sample are measured every 20 samples or daily if
less than 20 samples are analyzed each day9
Radionuclides are calibrated against a standard traceable to NIST
Standards are measured at a concentration in the sample concentration range
Counting standards are analyzed at the correct frequency as specified by the method or
the Manual for the Certification of Laboratories Analyzing Drinking Water
Calibration curves are verified for all radionuclides measured
Check standard records are maintained and include the following items:
• The name and/or number of the analytical method
• Name of the analyst
• Date and time of analyses
Yes
No
Comments
> • - •
5 Manual for the Certification of Laboratories Analyzing Drinking Water, Chapter VI,
section 7.6.2
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RADIOCHEMISTRY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
• Source of the standard material
• A description of any standard preparation steps (preparation date, name of the analyst who
prepared the standard, and reagents used)
• Concentration of the counting standard used
• Counting times
• All calculations and supporting data
Precision and Bias , ' ;
A minimum of 10 % duplicate samples are analyzed6
Method precision control limits are met for all radionuclides measured
Precision is determined at the correct frequency
Precision records are maintained and include the following items:
• Name and/or number of the method
• Name of the analyst
• Date and time of analyses
• The counter instrument used
• All calculations and supporting data
Spiked samples are measured regularly7
Standard materials traceable to MIST are used to spike samples
Method bias is determined for all radionuclides measured
Method bias control limits are met for all radionuclides measured
Spiked sample records are maintained and include the following items:
• Name and/or number of the method
• Name of the analyst •
• The date and time of analyses
• The source of the standards used
• A description of any standard preparations steps
Yes
No
!
Comments
!
. !
6 Manual for the Certification of Laboratories Analyzing Drinking Water, Chapter VI,
section 7.6.1
7 Handbook for Analytical Quality Control in Radioanalytical Laboratories, EPA/600/7-
77/088, pg. 4-11
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RADIOCHEMISTRY LABORATORY ANALYSIS REVIEW CHECKLIST
Laboratory Records
• Spike amounts added to the samples
• All calculations and supporting data
Instrument Performance
Laboratory monitors and documents instrument performance characteristics regularly, in
accordance with the method specifications and the equipment manufacturer's recommendations
Instrument performance records are maintained and include the following items:
• Initial and routine instrument calibration
• Analytical results from field and laboratory blanks
• Precision and bias
• Results of inter comparison cross check studies and performance evaluation studies
• Analytic*! results from background samples
Detection Limits*
The detector meets the minimum detectable activity requirements cited in 40 CFR 141.25
Counting times arc listed for each method, instrument, and radionuclide measured. (Sample
volumes should be documented for the corresponding counting time)
Laboratory Performance Evaluation
The laboratory analyzes, at least annually, water supply performance evaluation samples
within EPA limits
Performance evaluation records are maintained
The laboratory analyzes, at least semi-annually, EPA inter comparison cross check samples
within EPA limits'
Inter comparison cross check records are maintained
Corrective action is documented where performance problems are indicated by the PE study or
inter comparison cross check study results
Instrument Maintenance
Instrument maintenance schedules from manufacturers are followed and maintenance records
on all radiation instruments and analytical balances are maintained in a permanently bound
record"
Repair activities are recorded for all instruments
Yes
No
Comments
8 Standard Methods for the Examination of Water and Wastewater, 16th Ed., 1985
9 Manual for the Certification of Laboratories Analyzing Drinking Water, Chapter VI,
Section 7.2
10 Manual for the Certification of Laboratories Analyzing Drinking Water, Chapter VI,
Section 7.5
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DRINKING WATER CERTIFICATION
DATA AUDIT
DATA HANDLING AND REPORTING CHECKLIST
Laboratory Records
Calculations , - ' ' -
Written procedures for all calculations are available for review
Representative calculations are available and indicate that routine calculations are
consistent with the written procedures
All raw data and supporting information needed to recreate calculations are available for
review
All calculations are cross-checked by a second analyst
All data and calculations are certified by two analysts by signature with date in ink
QA plan includes SOP for preventing data errors
Sample and PE calculations verified by the auditor
Significant Figures
Significant figure conventions are followed
The appropriate number of significant figures are carried out through all recorded data
and calculations
The least precise step is identified in the calculations and the number of significant
figures is an accurate reflection of the actual tolerances of the instrument or equipment
used in this step.
Greater-Thatt and Less-Than. Values
Analyte concentrations with greater-than values are quantitatively diluted and reanalyzed
when possible
Less-than values are reported as "less than" (<) followed by the concentration of the
lowest standard used in the calibration curve or the MDL
For microbiological contaminants not detected, fecal colifonn and E. Coli are reported
as absent and Heterotrophic Plate Count (HPC) as < 1 per unit volume
For microbiological contaminants, greater than values for HPC are reported as "too
numerous to count" (TNTC)
Blank Corrections
Blank results are recorded with all other data and meet method specifications *
Blank measurements exceeding allowable analyte levels are reported and the affected
data are flagged
Data are never corrected for blank measurements unless specifically stated in the
analytical method utilized
Corrective action is documented to isolate and eliminate sources of contamination where
blank analyses indicate a consistent and significant problem
Yes
No
Comments
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DATA HANDLING AND REPORTING CHECKLIST
Laboratory Records
Data Security and Ba$k«XJp
A secure data system is maintained with limited access
Procedures arc in place to prevent unauthorized access
Procedures are in place to protect the integrity of the data
A log is maintained for laboratory file entries and retrievals
Computer software is documented and adequate for use
Original copies of analytical data and calculations (showing all corrections or changes)
are maintained on file and copies are tracked
Electronically stored data are supported with back up files
Yes
No
Comments
•U.S. Government Printing Office: 1997 - 549-001/60126
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