United States
Environmental Protection
Agency
UCMR 2: Fact Sheet for Screening
Survey of List 2 Contaminants


Title
Purpose
General
Description
Utilities
Covered
Overview of the Rule

Unregulated Contaminant Monitoring Regulation (UCMR) for Public Water Systems (PWSs) Revisions
To collect occurrence data for contaminants suspected to be present in drinking water, but that do not have health-based standards set under the Safe
Drinking Water Act. Screening Survey (List 2) monitoring targets contaminants that are analyzed by methods that utilize new technologies and are
not commonly used by drinking water laboratories. The UCMR monitoring program is the primary source of drinking water contaminant occurrence
data used by EPA in regulatory determinations.
The second cycle of the revised UCMR (UCMR 2) includes the Screening Survey (List 2) for 15 chemicals using 3 analytical methods. PWSs subject to
the Screening Survey will sample within a twelve month period during 2008 - 2010. Monitoring results for PWSs serving over 10,000 people, will be
reported using EPA's UCMR electronic data reporting system (i.e., the Safe Drinking Water Accession and Review System [SDWARS].)
Community water systems (CWSs) and non-transient non-community water systems (NTNCWSs) that serve a total population of more than 100,000
people, and a representative sample of 800 systems serving 100,000 or fewer will be required to participate in the Screening Survey.


Contaminant and CAS1
Registry Number 	
MRL2
(Mg/L)
Use or Environmental Source 1 Health Effects3
3 Acetanilide Parent Herbicides, by EPA Method 525.2
Acetochlor
34256-82-1
Alachlor
15972-60-8
Metolachlor
51218-45-2
2.0
2.0
1.0
Used as an herbicide on corn
Widely used herbicide, primarily used in the Midwest to control
annual grasses and broadleaf weeds on crops such as corn, sorghum,
and soybeans
Broad spectrum herbicide used for general weed control in non-
crop areas; widely used on crops such as corn, cotton, peanuts, grass
for seed production, nurseries, hedgerows/fencerows, and landscape
plantings
EPA reference dose (RfD) is 0.02 milligrams
per kilogram per day (mg/kg/day)
EPA RfD is 0.01 mg/kg/day
EPA RfD is 0.15 mg/kg/day
6 Acetanilide Herbicide Degradates, by EPA Method 535
Acetochlor ethane sulfonic acid (ESA)
187022-11-3
Acetochlor oxanilic acid (OA)
184992-44-4
Alachlor ESA
142363-53-9
Alachlor OA
171262-17-2
Metolachlor ESA
171118-09-5
Metolachlor OA
152019-73-3
1.0
2.0
1.0
2.0
1.0
2.0
Degradation product of acetochlor
Degradation product of alachlor
Degradation product of metolachlor
EPA RfD for parent herbicide, acetochlor, is
0.02 mg/kg/day
EPA RfD for parent herbicide, alachlor, is
0.01 mg/kg/day
EPA RfD for parent herbicide metolachlor is
0.15 mg/kg/day
6 Nitrosamines, bv EPA Method 521
N-nitrosodiethylamine (NDEA)
55-18-5
N-nitrosodimethylamine (NDMA)
62-75-9
N-nitroso-di-n-butylamine (NDBA)
924-16-3
N-nitroso-di-n-propylamine (NDPA)
621-64-7
N-nitrosomethylethylamine (NMEA)
10595-95-6
N-nitrosopyrrolidine (NPYR)
930-55-2
0.005
0.002
0.004
0.007
0.003
0.002
Nitrosamines can form as intermediates and byproducts in chemical
synthesis and manufacture of rubber, leather, and lastics; can form
spontaneously by reaction of precursor amines with nitrosating
agents (nitrate and related compounds), or by action of nitrate-
reducing bacteria. Foods such as bacon and malt beverages can
contain nitrosamines; there is also evidence that they form in the
upper Gl tract
EPA considers all six compounds to be
probable human carcinogens.
Chemical Abstracts Service
2 Minimum reporting level
3 Unregulated Contaminant Monitoring Regulation (UCMR) for Public Water Systems Revisions; Proposed Rule. Fed. Reg. Vol. 70, No. 161. p. 49093, August 22, 2005.

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Monitoring

Time frame
Frequency
Location
Laboratories
Groundwater
Surface Water or Groundwater Under the Direct Influence of Surface Water (GUDI)
One consecutive 12-month period during January 2008 - December 2010.
Monitoring will occur twice in a
consecutive 12-month period. Sample
events must occur 5-7 months apart.
Monitoring will occur in 4 consecutive quarters, with sampling events occurring 3 months apart.
Therefore, a system could conduct monitoring in either: (1) January, April, July, October; (2) February,
May, August, November; or (3) March, June, September, December.
EPA will assign a monitoring schedule; however, PWSs have the opportunity to change this schedule prior to the onset of monitoring.
Entry point to the distribution system for all List 2 contaminants. Additional sampling for nitrosamines (Method 521) is required at the distribution
system maximum residence time.
Samples must be analyzed by EPA-approved laboratories. EPA-approved laboratories will be listed on the UCMR Web site at
http://www.epa.gov/safewater/ucmr/ucmr2/labs.html.
                                   Critical Deadlines and Requirements
Due Date
Requirement
Report through
SDWARS1
Contact UCMR
Sampling Coordinator2
Following Rule Publication
Within 90 days of
rule publication
Within 120 days of
rule publication
Within 210 days of
rule publication
Systems must submit contact information to SDWARS.
(Any subsequent changes must be submitted within 30 days of the change.)
Laboratories wanting to be approved must submit a registration form to
participate in the laboratory approval process. For more information see:
http://www.epa.gov/safewater/ucmr/ucmr2/labs.html.
Groundwater systems that wish to monitor from representative EPTDSs must
submit either approval documentation or proposed alternate sampling plan.
Deadline for systems to change their
must provide an explanation for the
monitoring schedule (after 210 days systems
requested schedule change).
PWSs review, and edit if necessary, inventory information for sampling locations.
X


X
X

X
X
X (after 210 days)
X (after 210 days)
Following Sample Collection
Within 120 days of
sample collection
Within 60 days of
laboratory posting
of data
Laboratories post data to SDWARS.
PWSs review and approve the data. If after 60 days the PWS has not taken
action, the data are considered approved and ready for concurrent State and EPA
review.
X
X


1 Accessed through http://www.epa.gov/safewater/ucmr/ucmr2/reporting.html
2 Contact via e-mail at: UCMR_Sampling_Coordinator@epa.gov
UCMR 2 List 2 Data Elen
PWS Identification (PWSID)
PWS Facility Identification
Water Source Type
Sample Point Identification
Sample Point Type
Sample Collection Date
Sample Identification
Contaminant
Analytical Method
Sample Analysis Type
I
nents
Analytical Result - Sign
Analytical Results - Value
Laboratory Identification
Sample Event
Disinfectant Residual Type
Consumer Confidence Report
Under the Consumer Confidence Report (CCR) Rule, as specified in
40 CFR §141.153(d), 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.) Details on these
reporting requirements can be found on the CCR Home Page at:
http://www.epa.gov/safewater/ccr/index.html
For More Information....
Contact
UCMR Message Center
Safe Drinking Water Hotline
CDX/SDWARS Help Desk
Telephone
800 - 949 - 1581
800 - 426 - 4791
888-890-1995
Public Notification Rule
for unregulated contaminants are available (includes both CWSs and NTNCWSs).
CWSs may include their public notice within their CCRs. Details on these reporting
requirements can be found in the document: Public Notification Handbook (EPA
816-R-00-010), available on EPA's Web site at:
http://www.epa.gov/safewater/pws/pn/handbook.pdf.
Office of Water
EPA 815-F-06-006
December 2006

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