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Laboratory Quality
Assurance Evaluation Program for Analysis of Cryptosporidium under the
Safe Drinking Water Act
The purpose of this Laboratory Quality Assurance (Lab QA) Program is
to identify laboratories that can reliably measure the occurrence
of Cryptosporidium in
surface water using EPA
Method 1622 (PDF FILE, 1.17M) and/or EPA
Method 1623 (PDF FILE, 1.17M) . This program is voluntary,
and any laboratory may participate, provided the laboratory has: (1)
the equipment required in EPA Method 1622 and/or EPA Method 1623, (2)
personnel who have the recommended experience to analyze samples, and
(3) successfully completed an initial demonstration
of capability. The laboratory, personnel, and demonstration criteria
are specified in the Application
Cover Letter (PDF FILE, 104K) .
Steps for participation:
- Step 1. Application. The EPA will evaluate laboratory
applications for sufficient equipment, experience, and demonstration
of capability. Any deficiencies can be corrected before proceeding
to the next step in the evaluation process.
- Step 2. Initial proficiency test. After an application
has been accepted, the laboratory will be sent a set of eight initial
proficiency test (IPT) samples consisting of a suspension of oocysts
in a concentrated matrix. Laboratories will resuspend these spikes
in reagent water to produce simulated source water samples and analyze
the samples using the version of Method 1622/1623 that the laboratory
plans to use for routine Cryptosporidium analyses. If a
laboratory wishes to be evaluated for more than one version of the
method, the
laboratory will receive a set of eight IPT samples for each version.
Laboratory IPT data will be evaluated against mean recovery and
precision
(as relative standard deviation) criteria for the IPT samples.
- Step 3. On-site evaluation. After a laboratory
passes the IPT and has documented the required capability to participate
in the Lab QA Program through the completed application, an on-site
evaluation of the laboratory will be scheduled. The on-site
evaluation
will
include
two separate,
but
concurrent, assessments: (1) assessment of the laboratory’s
sample processing and analysis procedures, including microscopic
examination; and (2) evaluation of the laboratory’s personnel
qualifications, quality assurance and quality control, equipment,
and record keeping procedures.
After a laboratory has corrected any deficiencies noted in the audit,
they will be granted approval, pending promulgation of the LT2 Rule
and then will be listed with other laboratories that have
passed the
on-site evaluation at
http://www.epa.gov/safewater/lt2/aprvlabs.html.
- Step 4. On-going Proficiency Test. EPA will evaluate
on-going precision and recovery data to determine if the laboratory
continues to meet the performance criteria of the Laboratory QA Program.
Laboratories in the program will receive a set of three ongoing
proficiency test samples approximately every four months
that must be
analyzed in the same manner as the IPT samples.
All interested laboratories are encouraged to mail their application
package to:
Cryptosporidium Laboratory Quality Assurance Coordinator
c/o CSC Biology Studies Group
6101 Stevenson Avenue
Alexandria, VA 22304-3540
For technical inquiries contact:
Carrie Moulton, Manager, Cryptosporidium Laboratory Approval
Program
U.S. Environmental Protection Agency
Office of Ground Water and Drinking Water, Technical Support Center
26 West Martin Luther King Dr. (MS-140)
Cincinnati, Ohio 45268
fax number, (513) 569-7191
e-mail address, moulton.carrie@epa.gov
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