United States             Office of Water           EPA 815-F-01 -005
                      Environmental Protection     4606                  February 2001

 vxEPA        Unregulated  Contaminant
                      Monitoring  Regulation:
                      Screening  Survey for  List  2
                      Contaminants  by  Selected
                      Large  Public Water Systems
The 1996 Amendments to the Safe Drinking Water Act (SDWA) require the EPA to publish revisions to the Unregulated
Contaminant Monitoring Regulation (UCMR) establishing criteria for a program to monitor unregulated contaminants in
drinking water, and to publish a list of contaminants to be monitored. Under the UCMR, community water systems (CWSs)
and non-transient, non-community water systems (NTNCWSs) that serve more than 10,000 persons (large systems) will
monitor their water for the presence of unregulated contaminants, and report the results in electronic format to the U.S.
Environmental Protection Agency (EPA or Agency). A subset of these water systems will be required to participate in a
Screening Survey for the UCMR List 2 contaminants.

The purpose of UCMR monitoring is to collect contaminant occurrence data to support the U.S. EPA Administrator's
decisions regarding whether or not to regulate contaminants, such as those on the Drinking Water Contaminant Candidate
List, to protect public health. The Agency promulgated revisions to the UCMR, published in the Federal Register on
September 17, 1999 and supplemented on March 2, 2000. The UCMR List 2 Rule, which was finalized and published in the
Federal Register on January 11, 2001, also supplements the UCMR and is the focus of this fact sheet.

EPA has organized the UCMR contaminants into three lists based on the availability of analytical methods to detect their
presence in drinking water and on the type of monitoring to be conducted: Assessment Monitoring, List 1, consists of
contaminants for which standard analytical methods are available; Screening Survey, List 2, consists of contaminants for
which new analytical methods will be used; and Pre-Screen Testing, List 3, consists of contaminants for which analytical
methods are being researched. This fact sheet serves as a supplement to the initial UCMR fact sheet for large systems,
entitled: "Monitoring for List 1 Contaminants by Selected Large Public Water Systems". Table 1 identifies the Screening
Survey List 2 contaminants, which selected large systems are required to monitor, along with their environmental sources.

What Systems Must Monitor for List 2 Contaminants?  (See 141.40(a)(l))
While all large systems must conduct UCMR Assessment Monitoring for List 1 contaminants,  only a subset of these systems
will be required to conduct the UCMR Screening Surveys for List 2 contaminants. For each of the two  Screening Surveys,
120 large systems will be required to conduct sampling. If your system was selected to participate in one of the Screening
Surveys, you should have been notified by your State  drinking water agency or EPA.

When and How Often Must Monitoring Occur? (See 141.40(a)(5))
The first Screening Survey, for 13 chemical contaminants, will be conducted in 2002 by large systems.  Systems that use
surface water as their drinking water source will take samples for four consecutive quarters. Systems that have ground water
for their source will collect samples two times six months apart. All source water types must sample once during the
'vulnerable' period of May 1 through July 31, unless the State or EPA informs you that it has selected a different time period
for sampling as your system's vulnerable time. Table 2 provides a summary of the first Screening Survey sampling schedules
for surface water and ground water systems.

Table 1: UCMR (1999) List 2 Contaminants that are Required for Monitoring and Their Uses or Sources
Contaminant Name
Use or Environmental Source
Screening Survey Chemical Contaminants (2002)
1 ,2-diphenylhydrazine
Used in the production of benzidine and anti-inflammatory drugs
Released in automobile and diesel exhaust, coal tar and petroleum refining, and
Chemical intermediate in herbicide production
Released from mines, metal, petroleum, and dye plants
By-product of fossil fuel burning, used as bactericide and wood/glue preservative
Insecticide used with rice, fruit, vineyards, and corn crops
Insecticide used with cereal, cotton, tobacco, and potato crops
Herbicide used on grasses in orchards and wheat crops
Soil insecticide used on worms and centipedes
Herbicide used with corn, soybean, cotton, and wheat crops
Used in the production of aniline, which is used to make dyes, herbicides, and drugs
Herbicide used on annual and perennial weeds and grasses
Insecticide used with corn, sugar beet, and grain sorghum crops
Screening Survey Microbiological Contaminant (2003)
Present in all freshwater and brackish water
The second Screening Survey, for the List 2 microbiological contaminant Aeromonas, will be performed in 2003 by a
different set of 120 large systems. Aeromonas samples will be taken once each quarter, with additional samples taken each
month during the warmest quarter of the year, July through September (i.e., six times during the year). This means that
sampling must take place in each of the six (6) months of either: January, April, July, August, September, October; or
February, May, July, August, September, November; or March, June, July, August, September, December; unless the State
or EPA informs you otherwise.

Where Must Samples be Collected? (See 141.40(a)(5))
Sampling for Screening Survey chemical contaminants during 2002 must occur after treatment, at the entry point(s) to the
distribution system representing each non-emergency water source for your system. This only includes entry points for
sources that are in operation during the months in which sampling is to occur. Note that for List 2 sampling, source water
samples are not permitted.
Table 2: Monitoring Frequency by Source Water Type
Source Water Type
Surface Water
Ground Water
Monitoring Frequency
Four quarterly samples, taken as follows: Select either the first, second, or third month of a quarter and
sample in that same month of each of four consecutive quarters1 to ensure that one of these sampling
events occurs during the vulnerable time2
Two times in a year, taken as follows: Sample during one month of the most vulnerable time2 and during
one month five-to-seven months earlier or later3
1 . "Select either the first, second, or third month of a quarter and sample in that same month of each of four consecutive quarters" means that you must
monitor during each of four months in either: January, April, July, October; or February, May, August, November; or March, June, September, December.
2 ."Vulnerable time" means May 1 through July 31 , unless the State or EPA informs you that it has selected a different time period for sampling as your
system's vulnerable time.
3. "Sample during one month of the vulnerable time and during one month five to seven months earlier or later" means, for example, that if you select
May as your "vulnerable time" month to sample, then one month five to seven months earlier would be either October, November or December of the
preceding year, and one month five to seven months later would be either, October, November, or December of the same year.

Sampling for Aeromonas the Screening Survey microbiological contaminant in 2003 must occur at the three locations in the
distribution system that represent: a midpoint location in the distribution system with typical disinfectant residual levels, a
point located furthest from the entry point to the distribution system, and a location in the distribution system with the lowest
disinfectant residual. EPA will provide further guidance on Aeromonas sampling before systems are required to begin
collecting samples for this contaminant.
How Are the Samples to be
Analyzed? (See 141.40(a)(5)
and Appendix A)
Samples are to be analyzed by
State- or primacy agency-certified
laboratories, using methods
according to the UCMR's quality
control (QC) specifications. (For
details regarding applicable
methods and QC specifications,
see the Unregulated Contaminant
Monitoring Regulation Analytical
Methods and Quality Control
Manual [EPA 815-R-00-006], and
its supplements.) Because methods
for the analysis of List 2
contaminants have been newly
developed, no laboratories are
currently certified for these new
methods. To facilitate the approval
process, EPA is allowing for
automatic method certifications for laboratories that are already certified for specified EPA methods (which are similar to the
newly developed List 2 methods). These automatic method certifications, as specified under 141.40(a)(5)(ii)(G)(3), include:
Table 3: UCMR Data Elements for Reporting Sample Results
Public Water System (PWS) Identification
PWS Facility Identification Number -
Identification Number and Sampling Point Type
Sample Collection Date
Sample Identification Number
Analytical Results - Sign
Analytical Results- Value
Analytical Results - Unit of Measure
Analytical Method Number
Sample Analysis Type
Sample Batch Identification Number
Minimum Reporting Level
Minimum Reporting Level Unit of Measure
Analytical Precision
Analytical Accuracy
Spiking Concentration
                     If laboratory is certified
                     under 141.28 for EPA


                                    549. lor 549.2

                     coliform indicator bacteria using
                            EPA-approved membrane
                              filtration; plus special
                               Performance Testing
Then it is automatically approved
for UCMR Method:
                       526 or 528


     Will be certified for the method
            reserved for Aeromonas
To be approved for the Screening Survey for Aeromonas, laboratories must not only be certified for related coliform analysis
under 141.28, but must also successfully pass the Aeromonas Performance Testing (PT) Program that will be administered
by EPA. Further notification and guidance will be provided prior to commencement of the PT Program.

What Data Must be Reported to EPA? (See 141.35(d))
Analytical results that are reported must include the UCMR Data Elements listed in Table 3, above. Many of these are QC
measures, and should be provided by the laboratory.

How Will the Monitoring Data be Reported to EPA? (See 141.35(e))
Large public water systems have a few options by which to report the Screening Survey data to EPA:

        Systems can instruct their laboratories to electronically report to EPA on their behalf. After the data are submitted by
        the lab, the system can review its results on-line and electronically indicate its approval, or

        Systems can require their laboratories to receive their approval before the  laboratories report results to EPA.
If a system determines that its laboratory does not have the capability to report data electronically, the system may submit a
request to EPA to use an alternate reporting format. Under any circumstances, the results must be submitted to EPA within
30 days following the month the PWS receives the results. EPA will wait for an additional 60 days before placing the data in
the National Drinking Water Contaminant Occurrence Database to allow for quality control review by the system and the
State. Large systems are responsible for ensuring that a copy of the monitoring results is sent to the State.

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), CWSs must report the monitoring results whenever unregulated contaminants are detected. CCRs are to be sent to
all billing customers each year by July 1. (The CCR Rule does not apply to non-community water systems.) For NTNCWSs,
UCMR results will be made available to the public through the requirements of the revised Public Notification (PN) Rule (65
FR 25982), under 40 CFR 141.207. As required by the PN Rule, NTNCWSs must notify persons served by the system of
the availability of UCMR results within  12 months after the results are known. Because the revised PN Rule goes into effect
at different times in different States, owners and operators should check with their State drinking water agency to determine
which public notice requirements apply. 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 Web at www.epa.gov/safewater.

Where Can I Get More Information?
More information on the UCMR is available from the following
       Federal Register notices of September 17, 1999 (64 FR
       50556), March 2, 2000 (65 FR 11372), and January 11, 2001
       (66 FR 2273).
       The EPA Office of Ground Water and Drinking Water Web
       Site (www.epa.gov/safewater/ucmr.html).
       Unregulated Contaminant Monitoring Regulation Analytical
       Methods and Quality Control Manual (EPA 815-R-00-006).
       Supplement A to  the Unregulated Contaminant Monitoring
       Regulation Analytical Methods and Quality Control Manual
       (EPA 815-R-00-002).
       The Safe Drinking Water Hotline (800 426-4791).

EPA is developing additional guidance materials, so check the Office
of Ground Water and  Drinking Water UCMR Web Site often for the
latest information about them.

Table 4, at right, lists  UCMR contacts in the EPA regional offices and
the Agency's Technical Support Center in Cincinnati, OH.
Table 4: EPA UCMR Contacts
Region 1
Region 2
Region 3
Region 4
Region 5
Region 6
Region 7
Region 8
Region 9
Region 10
Chris Ryan
Robert Poon
Michelle Hoover
Janine Morris
Janet Kuefler
Andrew J. Waite
Stan Calow
Rod Glebe
Jill Korte
Gene Taylor
Dan Hautman
404 562-9480