United States
Environmental Protection
Agency
Office of Ground Water ' Technical
and Drinking Water	Support Division
EPA-814-K-92-001
May 1992
SEPA Labcert Bulletin
Welcome to the Fourth
Labcert	Bulletin
This is Labcert 4, the latest in a series of bulletins
dealing with recent items of interest to the
Drinking Water Certification Community.
We would like to introduce Carol Madding, the
newest member of the Drinking Water Laboratory
Certification team. She is the quality assurance officer
for the Technical Support Division (TSD) of the Office
of Ground Water and Drinking Water, and has until
recently been the quadrupole and high resolution
GC/MS operator at TSD. Feel free to contact her with
questions concerning QA, GC/MS, or laboratory
certification.
Watch for the next issue of Labcert Bulletin. It will
contain a table of all regulated analytes with methods and
preservation information. We will publish the next issue
as soon as possible after the promulgation of Phase V.
The Editors
Edward M. Glick
513-569-7939
Mary Ann Feige
513-569-7944
Carol Madding
513-569-7402
In This Issue	
Just What Does "USEPA Certified"
Really Mean 	1
Metals Digestion	1
Sharing Solutions: Our Readers Write
Isolation of Salmonella from Drinking
Water by the EC-MUG Test	2
Checking It Twice:
QC Verification Important	2
MMO-MUG Approved for E Coll with Subculturing	3
Lead and Copper Rule Monitoring	4
EMMC Activities Update	5
The Drinking Water Quality Monitoring Group . .	5
Resources 		6
Turbidity	7
Corrections and Updates to Labcert Bulletin 3 .	7
Just What Does
"USEPA Certified"
Really Mean
Recent magazine advertisements have taken issue
with what is meant when a calibration standard or
quality control sample is described as "USEPA Certi-
fied." USEPA Certified calibration standards and quality
control samples have been produced under strict EPA
technical specifications. They are verified for homoge-
neity, accuracy, and stability over their lifetime through
Calibration standards and quality
control samples are essential to an
effective quality control program.
analyses by multiple independent laboratories. They
are reviewed and approved by EPA prior to their distri-
bution to the public and are available for purchase from
a number of vendors.
In addition, EPA has entered into a Memorandum of
Understanding with the American Association for
Laboratory Accreditation (A2LA), under which
A2LA will provide independent certified reference
materials that are acceptable to EPA. These samples
must meet the same technical specifications
described above.
(Continued on page 3)
Metals Digestion
Many States and EPA Regions feel that digestion
of drinking water samples prior to metals analy-
sis is unnecessary. In a memo dated January 30, 1992,
James Conlon, Director of the Drinking Water Stand-
ards Division of the Office of Ground Water and Drink-
ing Water addressed this problem.
The memo states: "While digestion is necessary for
turbid water samples, it is not critical for non-turbid,
clean drinking water samples. It is our opinion that
when a sample contains less than 1 nephelometric
turbidity unit (NTU) and is properly preserved, the
sample may be analyzed directly (without digestion)
(Continued on page 3)
Labcert Bulletin
>

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Sharing Solutions: Our Readers Write
Salmonella Isolated from Drinking Water by the
EC-MUG Test
The Mississippi State Public Health Laboratory, Jackson, Mississippi, recently reported a Salmonella
isolation from a positive E. coli test. A private well sample (presumably untreated) tested positive
for total coliforms by the membrane filter technique and was confirmed in lauryl tryptose and brilliant
green lactose bile broths. Since drinking water (not private well) samples must be tested for fecal
coliforms or E. coli, growth was then transferred by swab to EC medium with MUG, and incubated at
44.5°C for 24hours. Strong fluorescence was produced in 24 hours and the sample was reported positive
for E. coli.
The MUG tube, however, appeared atypical, strongly fluorescent but with little growth, so further
subculture and biochemical characterization were performed. Enterobacter aerogenes, Pseudomonas
aeruginosa, and S. Inverness were detected. Testing of pure cultures showed the Salmonella isolate gave
positive fluorescence but little growth while the others did not fluoresce. No E. coli were detected. The
presence of Salmonella was recognized as significant and reported to the local health department for
corrective action. Other studies also have reported species other than E. coli to be MUG-positive.
Laboratories testing drinking water using MUG-containing confirmatory media should be aware that
occasional samples may test positive but contain MUG-utilizing species other than E. coli.
EPA's revised Laboratory Certification Manual requires that at least 5 percent of MUG positive and
turbid MUG negative results be verified.
If you havefurther questions on this subject, please call Joe Graves, Mississippi Department of Health,
601-960-7400 or Bob Bordner, U.S. Environmental Protection Agency, 513-569-7319.
Checking It Twice: QC Verification Important
Phosphate buffered dilution/rinse water, as described in Standard Methods, is required by EPA for
the bacteriological analysis of water and wastewater. The correct concentration of magnesium ions
is vitally important to protect environmentally injured bacterial cells. The 15th edition specified 38 grams
of anhydrous MgCfe per liter of water for the preparation of the stock. Since the anhydrous material is
not readily available, the 16th and 17th editions call for 81.1 grams of MgCl2-6H20 for the same
preparation. This change has caused some confusion. An individual or manufacturer might mistakenly
weigh out 38 grams of the hexahydrate. An incident occurred recently.
Buffered water, which is usually prepared in the laboratory, is also available from several commercial
sources. JackHalstuch of JH Consultants, Newtonville, New York, analyzed the Aid-Pack pre-filled
disposable buffered dilution water product, found the incorrect concentration of magnesium and
reported it to the manufacturer. We contacted Aid-Pack, who said they corrected this problem immedi-
ately after being notified by Mr. Halstuch. Pre-filled dilution bottles manufactured before May 30 1991
may be returned to the company and replaced. Please contact customer service for a return authorization-
Nancy Hamory
Aid-Pack, Inc.
Route 128, Blackburn Industrial Park
Gloucester, MA 01930
508-283-1800
This incident underscores the importance of requesting QC specifications from product manufacturers
and including QC procedures in the daily analytical routine, such as comparing bacterial recovery from
the new lot and a previously acceptable lot of the buffer, using the same sample.
To verify that preparations purchased from a vendor are correct, request a copy of the "certificate of
analysis" frori the manufacturer. The final concentration of magnesium in the working solution should
be 0.002 molar.

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MMO-MUG Approved for E. Coli with
Subculturing
In the Coliform Rule promulgated in the Federal Register, June 29,1989, EPA approved the use of the
MMO-MUG test and three other coliform methods for the analysis of total coliforms in drinking water.
The rule also stipulated that every total coliform positive sample must be tested for either fecal coliform
or E. coli. E. coli methods were not promulgated at this time. In the January 8,1991, Federal Register,
EPA approved the use of EC MUG and nutrient agar with MUG for E. coli, but not MMO-MUG, and
also restricted the transfer of cultures from this medium.
A Federal Register notice published on January 15, 1992, lifted this latter restriction. The notice
stated: "If a system uses the MMO-MUG test for total coliform detection, it must test all total
coliform-positive cultures for fluorescence. To test for fluorescence, use an ultraviolet light (366 nm) in
the dark after incubating the tube or container at 35±0.05°C for 24-28 hours. If fluorescence is observed,
the sample is E. co/i'-positive. If fluorescence is not observed, transfer 0.1 mL of the 28-hour culture to
EC medium + MUG with a pipet." The tube is then incubated at 44.5±0.2°C for 24+2 hours and checked
for fluorescence. A positive fluorescence result indicates the presence of E. coli.
In other words, a yellow color in the MMO-MUG test indicates a total coliform positive which must
be tested for fecal coliform or E. coli. Fluorescence in these positive results also indicates a positive for
E. coli. However, lack of fluorescence does not necessarily prove the absence of E. coli, and the sample
must be transferred to the EC medium + MUG for confirmation. A decision on whether this step will
continue to be required is expected from EPA Office of Ground Water and Drinking Water soon.
Just What Does "USEPA Certified" Really Mean
(Continued from page 1)
Calibration standards and quality control samples are
essential to an effective quality control program. Calibra-
tion standards are used to prepare or verify the accuracy
of the analyst's calibration curve while the quality control
samples are spiked into water and processed through the
entire method to determine if method recoveries are
adequate.
Another essential part of an effective quality control
program is the use of reference materials from different
sources. USEPA Certified calibration standards and
quality control samples are produced by different
manufacturers who use different starting materials
whenever possible.
Metals Digestion
(Continued from, page 1)
when using one of the following total element
techniques: graphite furnace AA, ICP-AES, ICP-MS,
or direct flame aspiration AA. Turbidity should be
measured on the preserved sample just prior to when
metal analyses are initiated. For gaseous hydride de-
termination of arsenic, antimony, or selenium, or for
the determination of mercury by the cold vapor tech-
nique, the proper digestion procedure must be fol-
lowed to ensure the element is in the proper chemical
state for analysis."
Although there is no requirement to use EPA or
A2LA Certified reference materials in the
certification program, the EPA 500 series methods
and the new EPA Manual for the Determination of
Metals in Environmental Samples (see
"Resources") state that quality control samples and
calibration standards be obtained from a source
external to the laboratory. Certified products un-
der the EPA and A2LA programs are produced and
checked to ensure their high quality. The quality of
other sources is unknown to the Agency and the
analyst must verify the acceptance of these
materials.
This is also in keeping with the recommendations in
the 17th edition of Standard Methods. If any of these
conditions are not met, then the digestion for total
recoverable metals must be used. This question of
digestion will be addressed in the forthcoming Phase
V rulemaking package.
If you have questions, contact your certification
officer, the editors, or Ivan DeLoatch of OGWDW at
202-260-2273.
3

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Lead and Copper Rule Monitoring
Monitoring requirements of the Lead and Copper
Rule are divided into initial monitoring, follow-up
monitoring, routine monitoring, and reduced monitoring
and are based on system size. Large public water systems
(PWSs), serving greater than 50,000people, began moni-
toring January 1,1992; medium PWSs, serving 3,301 to
50,000people, will begin monitoring for lead and copper
July 1, 1992; and small PWSs, serving 3,300 or less
people, will begin monitoring July 1,1993.
The initial monitoring requirement for large PWSs
consists of lead and copper first-draw tap samples,
water quality parameters in the distribution system,
and water quality parameters at the entry points to the
distribution system. Water quality parameters include
pH, temperature, conductivity, calcium, alkalinity,
orthophosphate, and silicate. These water quality
parameters do not need to be performed by a certified
laboratory but must be conducted using the methods
listed in the Federal Register.
If action levels for lead or copper are exceeded in
the initial monitoring for large systems, then lead and
copper determinations are required at the entry points
to the distribution system.
ing. Follow-up monitoring will be used by the States and
the PWSs to specify operating ranges for corrosion con-
trol after the installation of the required treatment
All laige systems, and those medium or small PWSs that
exceed an action level during the follow-up monitoring,
are required to conduct routine monitoring. Routine moni-
toring includes lead and copper first-draw tap samples and
water quality parameters as specified by the State.
Large systems meeting the water quality parameter
ranges set by the State under routine monitoring for
two consecutive periods can apply to the State for
reduced monitoring. Medium and small systems that
meet the action levels for two consecutive periods in
initial, follow-up, or routine monitoring can conduct
reduced monitoring. If a medium or small system
exceeds the action levels, but meets the water quality
parameter ranges set by the State under routine moni-
toring for two consecutive periods, the PWSs are
eligible for reduced monitoring.
The number of samples required for each phase of
monitoring is listed in the table below.
Several States and public water systems proposed
consolidation of tap water sampling and water quality

Minimum Number of Samples Required

Initial, Follow-up,


and Routine

System Size
Monitoring
Reduced Monitoring
Large PWSs


>100,000
100
50
50,000-100,000
60
30
Medium PWSs


10,001-50,000
60
30
3,301-10,000
40
20
Small PWSs


501-3,300
20
10
101-500
10
5
<100
5
5
Medium and small PWSs are required to collect lead
and copper first-draw tap samples at targeted sites under
initial monitoring. If the action levels are exceeded during
initial monitoring, then sampling is required for water
quality parameters in the distribution system and entry
points, and lead and copper in the entry points.
All large systems must conduct follow-up monitor-
ing for lead, copper, and the water quality parameters.
Only those medium or small PWSs that are required
to install treatment must conduct follow-up monitor-
parameter sampling in consecutive systems. EPA will
allow consolidation of sampling if the systems can
demonstrate they are interconnected in a manner that
justifies treating them as a single system. Prior to
allowing any consolidation under the Rule, the State
must submit to its EPA Regional office written expla-
nations of how monitoring, treatment, and reporting
requirements will be administered and enforced.
System proposals for consolidated sampling in
(Continued on page 5)
4

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EMMC Activities Update
The Environmental Monitoring Management Council (EMMC) was initiated to coordinate the activities of
the Agency to develop a uniform approach to sample determinations across program offices. Some of
EMMC's drinking water related activities follow:
¦	Validation of method 524.2 for VOCs across sample matrices. This validation is nearing completion and
includes reagent water, wastewater, drinking water, and soil.
¦	Development of criteria for performance-based methods to be used in lieu of, or as a supplement to, standard
approved analytical methods. Minimum required elements of performance, such as precision, bias, sensi-
tivity, specificity, and detection limits will be described. An available method would have to be shown to
meet these performance standards.
¦	National Accreditation of Environmental Laboratories is being considered by the Subcouncil on National
Accreditation for Laboratories. A report is expected in Fall of 1992.
¦	Consideration of a consolidated PE program that the Agency can use to reduce resource expenditures.
The Drinking Water Quality Monitoring Work
Group (DWQMWG)
The Drinking Water Quality Monitoring Work Group (DWQMWG) is composed of representatives of Federal,
State, and Private interests in the drinking water area.
Four subgroups have been assembled and are operating at different levels of activity to deal with issues
concerning regulations, certification, methods, and data handling/reporting.
In its first meeting, the work group prioritized 74 issues of concern to its members. Subgroups were formed
and began the task of trying to resolve the issues of highest priority. One issue, dealing with the redefinition of
detection and quantitation limits, is nearing solution.
Additional details and information about workgroup progress may be obtained by calling Herb Brass,
DWQMWG Chair, at 513-569-7936.
Lead and Copper Rule Monitoring
(Continued from page 4)
consecutive systems must identify which systems will 1
be held accountable for violation of the Rule's require-
ments including public education, source water moni-
toring, and lead service line replacement.	:
The details on EPA's position on consecutive sys-
tems can be found in a January 10, 1992, memo from
Jeff Cohen of the Lead Task Force to Regional Drink- <
ing Water Branch Chiefs. This memo clarifies the
discussion about consecutive systems in Chapter 2,
Volume / of the Guidance Manual. (Contact your
Regional Drinking Water Branch Chief or the Editors
for more information about this memo.)
The Lead and Copper Rule Guidance Manual,
Volume I, was developed to assist water systems in
implementing the monitoring requirements of the
Rule. Volume I may be purchased from NTIS (see
"Resources")- Volume 11 provides guidance on corro-
sion control studies and optimal treatment and will be
available in May 1992.
EPA will soon be issuing a correction notice for the
Lead and Copper Rule. Among other things, it will
clarify the digestion question (see article on "Metals
Digestion") and the preservation requirement. If sam-
ples cannot be preserved in the field, they may be
preserved to apH<2 when they reach the lab. They must
be held for an additional 16 to 28 hours before analysis.
For more information about the topics in this article
or implementation of the Lead and Copper Rule, con-
tact Barbara Wysock, Environmental Engineer,
OGWDW-TSD at 513-569-7906.
5

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RESOURCES
The following manuals are available
from NTIS:
Organic Methods Manuals
¦	Methods for the Determination of Organic Com-
pounds in Drinking Water (EPA/600/4-88/039,
NTIS# PB-89-220461/AS, Cost $43.00). This is
the latest revision, dated July 1991. It includes EPA
methods 502.1, 502.2, 503.1, 504, 505, 507, 508,
508A, 515.1, 524.1, 524.2, 525.1, and 531.1.
¦	Methods for the Determination of Organic Com-
pounds in Drinking Water, Supplement I
(EPA/600/4-90/020, NTIS# PB-91-146027, Cost
$35.00). Includes EPAmethods 506,513,547,548,
549, 550, 550.1, 551, and 552.
All quality control is built in to each method, each
of which is in a standardized format.
Metals Methods Manual
¦ Methods for the Determination of Metals in Envi-
ronmental Samples (EPA/600/4-91/010, NTIS#
PB-91-231498, Cost $43.00). Contains 13 analyti-
cal methods covering 35 analytes that may be pre-
sent in a variety of environmental sample types,
ranging from drinking water and municipal waste-
water to landfill leachate, biological tissue, and
soils. All quality control is built into each method
and the sample pre-treatment is included as a part
of each method. Includes EPA methods 200.1,
200.2, 200.3, 200.7, 200.8, 200.9, 200.10, 200.11,
218.6, 245.1, 245.3, 245.5, and 245.6.
Inorganics Methods Manual
¦	Methods for Chemical Analysis of Water and Wastes
(EPA/600/4-79/020, NTIS# PB-84-128677, Cost
$59.00).
Guidance Manuals
¦	Guidance Manual for Compliance with the Filtra-
tion and Disinfection Requirements for Public Water
Systems Using Surface Water Sources, October 1989,
NTIS# PB-90-148016/AS, Cost $50.00.
¦	Lead and Copper Guidance Manual, Volume I, Sep-
tember 1991, NTIS# PB-92-112101, Cost $35.00.
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
703-487-4650
800-553-6847
There is a $3.00 shipping and handling charge for
each order from NTIS.
3ioxin Method
¦ Method 1613: Tetra- through Octa-Chlorinated Di-
oxins and Furans by Isotope Dilution HRGC/HRMS
(Revision A)
This method may be ordered from:
USEPA OST
Sample Control Center
P.O. Box 1407
Alexandria, VA 22313
703-557-5040
Laboratory
Certification
1 The Manual for the Certification of Laboratories
Analyzing Drinking Water, Third Edition
(EPA/570/9-90/008)
Chapter V (Microbiology) of the manual has been
updated. The Office of Ground Water and Drinking
Water has published the revision as EPA 570/9-90-00-
008A, October 1991. The update reflects method
changes promulgated in the Coliform Rule and the
Surface Water Treatment Rule (June 29,1989), which
are now in effect for laboratory certification.
Chapter IV (Chemistry) is being updated and
should be completed by June 1992.
You can receive copies of the manual or chapter
updates by contacting your Regional Quality As-
surance Officer or the Editors.
The Safe Drinking
Water Hotline
The Hotline updates and interprets information
on EPA regulations and policies, locates technical
publications and guidance documents, and recom-
mends sources of public education and informa-
tion materials. It also can provide the name of
your State Certification Officer, from whom you
can obtain the name of a laboratory in your area
that is certified to test for drinking water
parameters.
The Hotline is available Monday through Fri-
day, 8:30am to 5:00pm EST (excluding federal
holidays). Call 1-800-426-4791 (in the United
States, Puerto Rico, and the Virgin Islands).
(Continued on page 7)
6

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RESOURCES
f Continuedfrom page 6)
Drinking Water
Laboratory Certification
Courses and Workshops
The Drinking Water Laboratory Certification
Courses for State Laboratory Certification Officers
will be held in Cincinnati on:
¦	July 13-17 for Chemistry (call Jack Pfaff,
513-569-7397)
¦	July 20-24 for Microbiology (call Bob Bordner,
513-569-7319)
A Drinking Water Labororatory Certification work-
shop is tentatively scheduled for Region 2. These
2-day workshops provide information on the Drinking
Water Regulations, analytical methodologies, and the
State certification programs.
Hirbidity
In the last Labcert Bulletin we notified you
of the availability of the pre-made for-
mazine standard solutions, (Contact Jim
O'Dell for the source at 513-569-7307.) This
allows laboratories to avoid potential expo-
sure to the toxic solutions needed to prepare
the formazine standards. These standards are
available as stock 4,000 NTU suspensions
and may be diluted as needed.
EPA's Office of Research and
Development Electronic
Bulletin Board (ORD BBS)
This free bulletin board provides information on
methods, research progress, Federal Register cita-
tions, EMSL-Ci QAmaterials, environmental publica-
tions, and meetings. A communications software
program (such as Crosstalk) and a computer modem
are necessary to use the system. The bulletin board
telephone numbers are:
513-569-7610 (1200 and 2400 baud)
800-258-9605 (9600 baud)
513-569-7700 (9600 baud)
For information, call Charles Guion at 513-569-
7272. The BBS currently contains a complete list of
all the wholesale and retail distributers of "USEPA
Certified" quality control samples. It also contains a
list of other bulletin boards and environmentally re-
lated information sources.
THIS NOTICE IS TO CAUTION
ANALYSTS USING POLYMER
STANDARDS WITH RATIO TYPE
TURBIDIMETERS.
The AMCO polymer (divinyl benzene) stand-
ards available through Advanced Polymer Sys-
tems are very stable (6 months) but are in some
cases instrument specific, and must be ordered by
instrument brand name. Using the wrong poly-
mer standard may give a lower value, especially
when the ratio type turbidimeters are used.
Corrections and Updates to Labcert Bulletin 3
The uranium MCLG was listed as 20 |ig/L.
The correct value is zero. Please change your copy.
Ascorbic Acid
In the last Labcert Bulletin, we reported on a potential problem using ascorbic acid as a reducing agent
for chlorinated samples. This notice is an update.
Several experiments have been conducted at TSD showing a loss of brominated THMs. This was first
brought to our attention by the New Mexico Health and Environmental Department.
Currently, we are conducting a mini-survey to determine the effect of ascorbic acid, with a comparison
to sodium thiosulfate, on "real world" samples. We will discuss the findings with EMSL-Ci and describe
the findings and our recommendations in the Labcert Bulletin. Under separate cover, we will send copies
of the findings to each State Certification Officer when the survey is completed.
For additional information, please contact one of the editors.

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