UCMR: Screening
| Survey for Aeromonas
at Selected Public
Water Systems
Introduction
In the first quarter of 2003 (January - March), selected public water systems (PWSs) must begin
monitoring for the List 2 microbiological contaminant, Aeromonas, as part of the Screening Survey
component of the Unregulated Contaminant Monitoring Regulation (UCMR 1999). This fact sheet is
designed to provide general information on the requirements of the Screening Survey for Aeromonas.
Under the 1996 Amendments to the Safe Drinking Water Act (SDWA), the U. S. Environmental
Protection Agency (EPA) was required to revise the existing unregulated contaminant monitoring
program by publishing a new list of unregulated contaminants and establishing criteria for a monitoring
program. In response to the 1996 SDWA Amendments, EPA established the UCMR (1999) as a three
tiered monitoring program, including: Assessment Monitoring (for List 1 contaminants); Screening
Surveys (for List 2 contaminants); and Pre-Screen Testing (for List 3 contaminants). A subset of
systems required to conduct the Assessment Monitoring are also required to participate in a Screening
Survey. The Screening Survey is conducted in two phases: the List 2 chemical contaminants and List
2 microbial contaminants. Aeromonas is the only microorganism on List 2 and will be monitored in
2003. For small systems (serving 10,000 persons or less), EPA will pay costs associated with sending
water samples to the appropriate laboratory, analyzing water samples, and reporting results. Large
systems are responsible for arranging and paying for monitoring, shipping, testing, and reporting of
results.
The purpose of unregulated contaminant monitoring is to collect data on contaminants to support the
EPA Administrator's decisions regarding whether or not to regulate contaminants. The Agency
promulgated the UCMR on September 17, 1999 (64 FR 50556) with a supplemented to the Rule on
March 2, 2000 (65 FR 11372). The UCMR List 2 Rule, finalized and published in the Federal Register
on January 11, 2001, detailed the monitoring specifications for the Screening Survey component of the
UCMR (1999) (including for Aeromonas) and approved analytical methods for the List 2 chemical
contaminants. An analytical method for Aeromonas, was approved and published in the Federal
Register on October 29, 2002 (67 FR 65888).
What Systems Must Monitor for Aeromonas? (See §141.40(a)(1))
The Screening Survey for Aeromonas will be conducted by 120 large and 180 small systems randomly
selected from a pool of systems that are required to conduct Assessment Monitoring. Systems
selected to participate in the Screening Survey for Aeromonas, have been notified by their state
drinking water agency or EPA. The list of systems selected to participate in the Screening Survey is
posted on the Internet at http://www.epa.gov/safewater/standard/ucmr/systems.html.
When and How Often Must Monitoring Occur? (See §141.40(a)(7))
Monitoring for Aeromonas can begin in January 2003 for all selected large and small systems.
Aeromonas samples will be taken every three months, with additional samples taken each month
during the warmest months of the year (July, August, September). Therefore, monitoring will take
place six times during the year with one of three possible monitoring schemes: 1) January, April, July,
August, September, and October; 2) February, May, July, August, September, and November; or 3)
March, June, July, August, September, and December.
If for any reason a sample becomes invalidated, resampling should take place as soon as possible
within the regulatory defined sampling periods.
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Where Must Samples be Collected? (See §141.40(a)(7))
Samples for Aeromonas must be taken at three locations in the distribution system that represent the
following: a midpoint location (MD) in the distribution system with typical disinfectant residual levels, a
location representing the maximum residence time (MR) in the distribution system, and a location in the
distribution system with the lowest disinfectant residual (LD). To the extent possible, systems may
sample for Aeromonas in the same locations identified for regulated contaminants that meet these
criteria for Aeromonas sampling points. This may include some sampling points used for monitoring
coliform indicator bacteria (as specified under the Total Colifprm Rule - §141.21), or total
trihalomethanes (TTHM) (as specified under the Stage 1 Disinfectants and Disinfection Byproducts
Rule-§141.132). Further information on sampling locations can be found in §141.40(a)(3) Table 1,
List 2 footnote g.
Many states have agreed to collect the UCMR samples for selected small systems. If the state has not
agreed to do this, the selected small system must collect the samples with EPA-supplied equipment,
and send them to an EPA-specified laboratory. The state or EPA will inform selected small systems of
who will be responsible for collecting the samples.
Is Monitoring For Other Water Quality Parameters Required? (See §141.40(a)(4)(i)(B))
Yes. Water quality parameters must be analyzed and reported when monitoring for Aeromonas as
part of the Screening Survey. These parameters include water pH, turbidity, temperature, and free and
total disinfectant residual.
How Are the Samples to be Analyzed? (See §§141.40(a)(7) and Appendix A)
Aeromonas samples must be analyzed by laboratories that are approved by EPA to perform analysis
using EPA Method 1605. In order to receive approval, laboratories must: 1) be certified to perform
coliform indicator bacteria compliance analysis using membrane filtration, and 2) have successfully
passed an EPA proficiency testing (PT) study for EPA Method 1605. EPA will conduct PT studies prior
to the start of Aeromonas monitoring in January 2003. All laboratory analyses must adhere to the
UCMR's quality control (QC) specifications in §141.40 Appendix A and as defined in Method 1605.
Specific QC requirements and other considerations have been summarized in the following section.
(For additional details regarding QC specifications, see Method 1605: Aeromonas in Finished Water by
Membrane Filtration Using Ampicillin-Dextrin Agar with Vancomycin (ADA-V) [EPA-821-R-01-034]
available on the Internet at http://www.epa.gov/nerlcwww/1605ot01 .pdf.) EPA has posted a list of
laboratories approved to perform Aeromonas analyses on the Internet at
http://www.epa.gov/safewater/standard/ucmr/aprvlabs.html.
Because EPA will pay for the analysis of Aeromonas samples taken at small systems, EPA has
arranged for specific approved laboratories to conduct the testing. Small systems need not make any
arrangements for sample analysis.
Important QC requirements and general information for approved Aeromonas laboratories
1. Laboratories are not expected to conduct a detection limit calculation for Aeromonas as identified in
Appendix A (2) of the UCMR, because this requirement is only applicable to the UCMR chemical
contaminant methods.
2. Laboratories are not expected to conduct a calibration or calibration verification for Aeromonas as
identified in Appendix A (3) of the UCMR, because this requirement is only applicable to the UCMR
chemical contaminant methods.
3. Laboratories must adhere to all the quality control (QC) requirements in EPA Method 1605 Section
9.0, which includes passing an initial demonstration of capability (IDC) (EPA Method 1605, Section
9.4) and processing dilution/rinse water blanks (EPA Method 1605, Section 9.5) and negative
culture controls (EPA Method 1605, Section 9.6)
4. On an on-going basis, laboratories must pass the on-going demonstration of capability (ODC)
requirements specified in EPA Method 1605 Section 9.8. These include one set of positive
control/positive control duplicate (PC/PCD) samples with every 20 field and matrix spike samples,
or one set per week, whichever occurs more frequently.
5. The laboratory must analyze matrix spike and matrix spike duplicates (MS/MSD) samples when
samples are first received from a PWS (EPA Method 1605, Section 9.7) and subsequently 5
percent of all samples received. Appendix A (6) of the UCMR includes specific directions about
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MS/MSD. This requirement can be met by collecting an additional sample volume from one of the
three sampling locations (either MD, MR, or LD) and not only filtering this sample unspiked as
usual, but also filtering it as a prepared MS/MSD pair. Also under Appendix A (6) of the UCMR,
concentrations for prepared MS/MSD samples are specified to alternate between concentrations at
± 20 percent of the minimum reporting level and ± 20 percent of a mid level calibration standard.
This requirement is specific to chemical contaminant methods. For Aeromonas , laboratories
should choose anticipated MS/MSD fortifications to range from 20 to 60 colony forming units (CPU)
per filter.
6. Most water quality parameter data must be measured when field samples are collected at the
designated monitoring location. These required field measurements include water temperature,
pH, and free and total disinfectant residual (typically as chlorine). Turbidity is the last water quality
parameter, which can be measured either in the field, at the water system's wet laboratory, or as
applicable, at the contract Aeromonas laboratory. If the turbidity sample is sent to the Aeromonas
laboratory, it must be measured within 48 hours of sample collection. If the Aeromonas laboratory
will make the turbidity measurement, be certain that the laboratory provides an appropriate
sampling bottle in the Aeromonas sampling kit they send to the system. All of these water quality
parameter data must be reported with the Aeromonas results to EPA.
7. Aeromonas samples MUST be preserved by the use of EDTA and/or sodium thiosulfate (EPA
Method 1605, Section 8.2) and be transported to the laboratory under refrigeration (EPA Method
1605, Section 8.3). Samples must be processed by the laboratory within 30 hours of collection at
the PWS. Water systems should wait until afternoon to collect their samples and the samples must
be received at an approved Aeromonas laboratory by the next morning, e.g., overnight express.
These samples must be initially filtered the day they are received at the laboratory.
8. Presumptive colonies must be confirmed (EPA Method 1605, Section 10.11). Only presumptive
colonies which have been fully confirmed (i.e., have passed all three confirmation steps) are to be
reported as positive detections.
9. The laboratory should be careful to report concentrations as CFU/100 ml_, recognizing that a total
of 500 mL of sample is filtered.
How Will the Monitoring Data be Reported to EPA?
Prior to the start of the Screening Survey for Aeromonas in January 2003, EPA will provide instructions
to each selected large system on how to report monitoring data. Each large PWS will receive an e-
mail with six Microsoft Excel™ spreadsheets attached. These spreadsheets will correspond to each
month in which the PWS is to collect Aeromonas samples. In addition, near the beginning of each
month for which it is to sample, the PWS will receive a follow-up e-mail that contains the appropriate
spreadsheet and a reminder of their monitoring requirement.
While there is flexibility in who completes the various portions of the spreadsheet, EPA recommends
the following approach: The PWS will collect its Aeromonas samples and enter the relevant water
quality parameters into the spreadsheet. The samples and spreadsheet will be sent to an approved
Aeromonas laboratory. The laboratory will analyze the samples and complete the relevant portion of
the spreadsheet. It will then send the spreadsheet back to the PWS. The PWS will approve the data,
recording within the spreadsheet the PWS approval date. The PWS will then send the spreadsheet to
EPA as an e-mail attachment.
EPA will provide an overview of the reporting system with instructions for filling in the spreadsheet to
large PWSs and approved laboratories. Any large system that does not have access to e-mail will
receive its reporting sheets via U.S. mail. These PWSs will return the completed sheets to EPA via
U.S. mail. Small systems required to monitor for Aeromonas will receive their results in an EPA
prepared report sent directly to them.
Are There Requirements for Notifying the Public? (See §141.153(d) and §141.207)
Yes. Under the Consumer Confidence Report (CCR) Rule (40 CFR 141.153(d)), published on August
19, 1998 (63 FR 44511), PWSs must report the monitoring results whenever unregulated contaminants
are detected. The Public Notification (PN) Rule (65 FR 25982) also applies to unregulated
contaminants.
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The main component of the CCR will be a table displaying the levels of detected contaminants,
including unregulated contaminants, in finished water. For each detected unregulated contaminant for
which monitoring is required, the table must display the average of any monitoring results from the year
and the range of detections. A system may briefly explain in the CCR why it is monitoring for
unregulated contaminants. The explanation may read as follows:
Unregulated contaminants are those for which EPA has not established drinking water standards.
The purpose of unregulated contaminant monitoring is to assist EPA in determining the occurrence
of unregulated contaminants in drinking water and whether future regulation is warranted.
Further details on these reporting requirements can be found in the documents: Preparing Your
Drinking Water Consumer Confidence Report (EPA 816-R-99-002) and Public Notification Handbook
(EPA 816-R-00-010). Both are available on the Internet at http://www.epa.qov/safewater/ccr1 .html and
http://www.epa.gov/safewater/pn.html. or by calling the Safe Drinking Water Hotline at (800) 426-4791.
Where Can I Get More Information?
More information on the Aeromonas Screening Survey is available from the following sources:
• Federal Register notices of January 11, 2001 (66 FR 2273) and Final Rule October 29, 2002 (67
FR 65888).
• The EPA Office of Ground Water and Drinking Water UCMR Web Site
(http://www.epa.gov/safewater/ucmr.html).
Method 1605: Aeromonas in Finished Water by Membrane Filtration using Ampicillin-Dextrin Agar
with Vancomycin (ADA-V) (EPA-821-R-01-034, October 2001).
• The Safe Drinking Water Hotline 1-800-426-4791.
Table 1, at right, lists UCMR contacts in the EPA regional offices and the Agency's Technical Support
Center in Cincinnati, Ohio.
Table 1 : EPA UCMR Contacts
EPA
Region 1
Region 2
Region 3
Region 4
Region 5
Region 6
Region 7
Region 8
Region 9
Region 10
Technical
Support
Center
Contact
Chris Ryan
Robert Poon
Michelle Hoover
Janine Morris
Janet Kuefler
Andrew J. Waite
Stan Calow
Rod Glebe
Jill Korte
Gene Taylor
Dan Hautman
Telephone
617918-1567
212637-3821
215814-5258
404 562-9480
312886-0123
214 665-7332
913551-7410
303312-6627
415972-3562
206553-1389
513569-7948
Office of Ground Water and Drinking Water
(4601)
EPA-815-F-02-007
www.epa.gov/safewater
October 2002
Printed on Recycled Paper
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