[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR141.40]

[Page 426-435]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 141_NATIONAL PRIMARY DRINKING WATER REGULATIONS--Table of Contents
 
  Subpart E_Special Regulations, Including Monitoring Regulations and 
 
Sec. 141.40  Monitoring requirements for unregulated contaminants.

                         Prohibition on Lead Use


    (a) General applicability. This section specifies the monitoring and 
quality control requirements that must be followed if you own or operate 
a public water system (PWS) that is subject to the Unregulated 
Contaminant Monitoring Regulation (UCMR), as specified in paragraphs 
(a)(1) and (2) of this section. In addition, this section specifies the 
UCMR requirements for State and Tribal participation. For the purposes 
of this section, PWS ``population served,'' ``State,'' `` PWS 
Official,'' ``PWS Technical Contact,'' and ``finished water'' apply as 
defined in Sec. 141.35(a). The determination of whether a PWS is 
required to monitor under this rule is based on the type of system 
(e.g., community water system, non-transient non-community water system, 
etc.); whether the system purchases all of its water, as finished water, 
from another system; and its population served as of June 30, 2005.
    (1) Applicability to transient non-community systems. If you own or 
operate a transient non-community water system, you do not have to 
monitor that system for unregulated contaminants.
    (2) Applicability to community water systems and non-transient non-
community water systems.
    (i) Large systems. If you own or operate a wholesale or retail PWS 
(other than a transient non-community system) that serves more than 
10,000 people, and do not purchase your entire water supply as finished 
water from another PWS, you must monitor according to the specifications 
in this paragraph (a)(2)(i). If you believe that your applicability 
status is different than EPA has specified in the notification letter 
that you received, or if you are subject to UCMR requirements and you 
have not been notified by either EPA or your State, you must report to 
EPA, as specified in Sec. 141.35(b)(2) or (c)(4).
    (A) Assessment Monitoring. You must monitor for the unregulated 
contaminants on List 1 of Table 1, UCMR Contaminant List, in paragraph 
(a)(3) of this section. If you serve a population of more than 10,000 
people, you are required to perform this monitoring regardless of 
whether you have been notified by the State or EPA.
    (B) Screening Survey. You must monitor for the unregulated 
contaminants on List 2 (Screening Survey) of Table 1, as specified in 
paragraph (a)(3) of this section, if your system serves 10,001 to 
100,000 people and you are notified by EPA or your State that you are 
part of the State Monitoring Plan for Screening Survey testing. If your 
system serves more than 100,000 people, you are required to conduct this 
Screening Survey testing regardless of whether you have been notified by 
the State or EPA.
    (C) Pre-Screen Testing. You must monitor for the unregulated 
contaminants on List 3 of Table 1, in paragraph (a)(3) of this section, 
if notified by your State or EPA that you are part of the Pre-Screen 
Testing.
    (ii) Small systems. Small PWSs, as defined in this paragraph, will 
not be selected to monitor for any more than one of the three monitoring 
lists provided in Table 1, UCMR Contaminant List, in paragraph (a)(3) of 
this section.

[[Page 427]]

EPA will provide sample containers, provide pre-paid air bills for 
shipping the sampling materials, conduct the laboratory analysis, and 
report and review monitoring results for all small systems selected to 
conduct monitoring under paragraphs (a)(2)(ii)(A) through (C) of this 
section. If you own or operate a PWS (other than a transient system) 
that serves 10,000 or fewer people and do not purchase your entire water 
supply from another PWS, you must monitor as follows:
    (A) Assessment Monitoring. You must monitor for the unregulated 
contaminants on List 1 of Table 1, in paragraph (a)(3) of this section, 
if you are notified by your State or EPA that you are part of the State 
Monitoring Plan for Assessment Monitoring.
    (B) Screening Survey. You must monitor for the unregulated 
contaminants on List 2 of Table 1, in paragraph (a)(3) of this section, 
if notified by your State or EPA that you are part of the State 
Monitoring Plan for the Screening Survey.
    (C) Pre-Screen Testing. You must monitor for the unregulated 
contaminants on List 3 of Table 1, in paragraph (a)(3) of this section, 
if you are notified by your State or EPA that you are part of the State 
Monitoring plan for Pre-Screen Testing.
    (3) Analytes to be monitored. Lists 1, 2, and 3 of unregulated 
contaminants are provided in the following table:

                                                              Table 1--UCMR Contaminant List
                                                  [List 1: Assessment Monitoring Chemical Contaminants]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           2--CAS                                                                                     6--Period during
            1--Contaminant                registry       3--Analytical methods     4--Minimum reporting      5--Sampling location    which monitoring to
                                           number                 \a\                    level \b\                   \c\                be completed
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dimethoate...........................         60-51-5  EPA 527 \d\.............  0.7 [mu]g/L.............  EPTDS..................   1/1/2008-12/31/2010
Terbufos sulfone.....................      56070-16-7  EPA 527 \d\.............  0.4 [mu]g/L.............  EPTDS..................   1/1/2008-12/31/2010
2,2[min],4,4[min]-tetrabromodiphenyl        5436-43-1  EPA 527 \d\.............  0.3 [mu]g/L.............  EPTDS..................   1/1/2008-12/31/2010
 ether (BDE-47).
2,2[min],4,4[min],5-                       60348-60-9  EPA 527 \d\.............  0.9 [mu]g/L.............  EPTDS..................   1/1/2008-12/31/2010
 pentabromodiphenyl ether (BDE-99).
2,2[min],4,4[min],5,5[min]-                59080-40-9  EPA 527 \d\.............  0.7 [mu]g/L.............  EPTDS..................   1/1/2008-12/31/2010
 hexabromobiphenyl (HBB).
2,2[min],4,4[min],5,5[min]-                68631-49-2  EPA 527 \d\.............  0.8 [mu]g/L.............  EPTDS..................   1/1/2008-12/31/2010
 hexabromodiphenyl ether (BDE-153).
2,2[min],4,4[min],6-                      189084-64-8  EPA 527 \d\.............  0.5 [mu]g/L.............  EPTDS..................   1/1/2008-12/31/2010
 pentabromodiphenyl ether (BDE-100).
1,3-dinitrobenzene...................         99-65-0  EPA 529 \e\.............  0.8 [mu]g/L.............  EPTDS..................   1/1/2008-12/31/2010
2,4,6-trinitrotoluene (TNT)..........        118-96-7  EPA 529 \e\.............  0.8 [mu]g/L.............  EPTDS..................   1/1/2008-12/31/2010
Hexahydro-1,3,5-trinitro-1,3,5-              121-82-4  EPA 529 \e\.............  1 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
 triazine (RDX).
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                              Table 1--UCMR Contaminant List
                                                     [List 2: Screening Survey Chemical Contaminants
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           2--CAS                                                                                     6--Period during
            1--Contaminant                registry       3--Analytical methods     4--Minimum reporting      5--Sampling location    which monitoring to
                                           number                 \a\                    level \b\                   \c\                be completed
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                       Acetanilide Pesticide Degradation Products
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acetochlor ESA.......................     187022-11-3  EPA 535 \f\.............  1 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
Acetochlor OA........................     184992-44-4  EPA 535 \f\.............  2 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
Alachlor ESA.........................     142363-53-9  EPA 535 \f\.............  1 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
Alachlor OA..........................     171262-17-2  EPA 535 \f\.............  2 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
Metolachlor ESA......................     171118-09-5  EPA 535 \f\.............  1 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
Metolachlor OA.......................     152019-73-3  EPA 535 \f\.............  2 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Acetanilide Pesticide Parent Compounds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acetochlor...........................      34256-82-1  EPA 525.2 \g\...........  2 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
Alachlor.............................      15972-60-8  EPA 525.2 \g\...........  2 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
Metolachlor..........................      51218-45-2  EPA 525.2 \g\...........  1 [mu]g/L...............  EPTDS..................   1/1/2008-12/31/2010
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 428]]


                                                                      Nitrosamines
--------------------------------------------------------------------------------------------------------------------------------------------------------
N-nitrosodiethylamine (NDEA).........         55-18-5  EPA 521 \h\.............  0.005 [mu]g/L...........  DSMRT and EPTDS........   1/1/2008-12/31/2010
N-nitroso-dimethylamine (NDMA).......         62-75-9  EPA 521 \h\.............  0.002 [mu]g/L...........  DSMRT and EPTDS........   1/1/2008-12/31/2010
N-nitroso-di-n-butylamine (NDBA).....        924-16-3  EPA 521 \h\.............  0.004 [mu]g/L...........  DSMRT and EPTDS........   1/1/2008-12/31/2010
N-nitroso-di-n-propylamine (NDPA)....        621-64-7  EPA 521 \h\.............  0.007 [mu]g/L...........  DSMRT and EPTDS........   1/1/2008-12/31/2010
N-nitroso-methylethylamine (NMEA)....      10595-95-6  EPA 521 \h\.............  0.003 [mu]g/L...........  DSMRT and EPTDS........   1/1/2008-12/31/2010
N-nitrosopyrrolidine (NPYR)..........        930-55-2  EPA 521 \h\.............  0.002 [mu]g/L...........  DSMRT and EPTDS........   1/1/2008-12/31/2010
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                              Table 1--UCMR Contaminant List
                               [List 3: Pre-Screen Testing to be Sampled After Notice of Analytical Methods Availability]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           2--CAS                                                                                     6--Period during
            1--Contaminant                registry       3--Analytical methods     4--Minimum reporting      5--Sampling location    which monitoring to
                                           number                 \a\                    level \b\                   \c\                be completed
--------------------------------------------------------------------------------------------------------------------------------------------------------
Reserved \i\.........................    Reserved \i\  Reserved \i\............  Reserved \i\............  Reserved \i\...........          Reserved \i\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Column headings are:
1--Contaminant: The name of the contaminant to be analyzed.
2--CAS (Chemical Abstract Service) Registry Number or Identification Number: A unique number identifying the chemical contaminants.
3--Analytical Methods: method numbers identifying the methods that must be used to test the contaminants.
4--Minimum Reporting Level: The value and unit of measure at or above which the concentration of the contaminant must be measured using the approved
  analytical methods.
5--Sampling Location: The locations within a PWS at which samples must be collected.
6--Period During Which Monitoring to Be Completed: The dates during which the sampling and testing are to occur for the indicated contaminant.

 The analytical procedures shall be performed in accordance with the documents associated with each method (per the following footnotes). The
  incorporation by reference of the following documents listed in footnotes d--h was approved by the Director of the Federal Register in accordance with
  5 U.S.C. 552(a) and 1 CFR part 51. Information on how to obtain these documents can be provided by the Safe Drinking Water Hotline at (800) 426-4791.
  Documents may be inspected at EPA's Drinking Water Docket, 1301 Constitution Avenue, NW., EPA West, Room B102, Washington, DC 20460, Telephone: (202)
  566-2426; or at the National Archives and Records Administration (NARA). For information on availability of this material at NARA, call 202-741-6030,
  or go to:http://www.archives.gov/federal-register/index.html.
\a\ The version of the EPA methods which you must follow for this Regulation are listed in d--h as follows.
\b\ The Minimum Reporting Level (MRL) was established by EPA by adding the mean of the Lowest Concentration Minimum Reporting Levels (LCMRL) determined
  according to the procedure detailed in ``Statistical Protocol for the Determination of The Single-Laboratory Lowest Concentration Minimum Reporting
  Level (LCMRL) and Validation of the Minimum Reporting Level (MRL)'' by the primary and secondary laboratories conducting the development and
  validation of the analytical method to three times the difference of the LCMRLs. If LCMRL data from three or more laboratories were available, the MRL
  was established by EPA by adding three times the standard deviation of the LCMRLs to the mean of the LCMRLs. Note that EPA Method 525.2 was developed
  prior to UCMR 2, hence the LCMRLs were not determined for analytes determined by this method.
\c\ Sampling must occur at entry points to the distribution system (EPTDSs) after treatment is applied that represent each non-emergency water source in
  routine use over the 12-month period of monitoring. See 40 CFR 141.35(c)(3) for an explanation of the requirements related to use of representative
  EPTDSs. Sampling for nitrosamines on List 2 must also occur at the disinfection byproduct distribution system maximum residence time (DSMRT) sampling
  locations as defined in 40 CFR 141.132(b)(1)(i) and at EPTDS sampling locations. If a treatment plant/water source is not subject to the sampling
  required in 40 CFR 141.132(b)(1), then the samples for nitrosamines must be collected only at the EPTDS location(s).
\d\ EPA Method 527 ``Determination of Selected Pesticides and Flame Retardants in Drinking Water by Solid Phase Extraction and Capillary Column Gas
  Chromatography/Mass Spectrometry (GC/MS),'' Revision 1.0, April 2005 is available at http://www.epa.gov/safewater/methods/sourcalt.html.
\e\ EPA Method 529 ``Determination of Explosives and Related Compounds in Drinking Water by Solid Phase Extraction and Capillary Column Gas
  Chromatography/Mass Spectrometry (GC/MS),'' Revision 1.0, September 2002 is available at http://www.epa.gov/nerlcwww/ordmeth.htm.
\f\ EPA Method 535 `` Measurement of Chloroacetanilide and Other Acetamide Herbicide Degradates in Drinking Water by Solid Phase Extraction and Liquid
  Chromatography/Tandem Mass Spectrometry (LC/MS/MS),'' Version 1.1, April 2005 is available at http://www.epa.gov/nerlcwww/ordmeth.htm.
\g\ EPA Method 525.2 ``Determination of Organic Compounds in Drinking Water by Liquid-Solid Extraction and Capillary Column Gas Chromatography/Mass
  Spectrometry,'' Revision 2.0, 1995 is available at http://www.NEMI.gov.
\h\ EPA Method 521 ``Determination of Nitrosamines in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography with Large Volume
  Injection and Chemical Ionization Tandem Mass Spectrometry (MS/MS),'' Version 1.0, September 2004 is available at http://www.epa.gov/nerlcwww/
  ordmeth.htm.
\i\ To be determined at a later time.


[[Page 429]]

    (4) Sampling requirements--(i) Large systems. If you serve more than 
10,000 people and meet the UCMR applicability criteria specified in 
paragraph (a)(2)(i) of this section, you must comply with the 
requirements specified in paragraphs (a)(4)(i)(A) through (I) of this 
section. Your samples must be collected according to the schedule that 
you are assigned by EPA or your State, or the schedule that you revised 
using EPA's electronic data reporting system on or before August 2, 
2007. Your schedule must follow both the timing and frequency of 
monitoring specified in Tables 1 and 2 of this section.
    (A) Monitoring period. You must collect the samples in one 
continuous 12-month period for List 1 Assessment Monitoring, and, if 
applicable, for List 2 Screening Survey, or List 3 Pre-Screen Testing, 
during the time frame indicated in column 6 of Table 1, in paragraph 
(a)(3) of this section. EPA or your State will specify the month(s) and 
year(s) in which your monitoring must occur. As specified in Sec. 
141.35(c)(5), you must contact EPA if you believe you cannot conduct 
monitoring according to your schedule.
    (B) Frequency. You must collect the samples within the time frame 
and according to the frequency specified by contaminant type and water 
source type for each sampling location, as specified in Table 2, in this 
paragraph, with the following exception. For the second round of ground 
water sampling, if a sample location is non-operational for more than 
one month before and one month after the scheduled sampling month (i.e., 
it is not possible for you to sample within the five to seven month 
window specified the Table 2, in this paragraph), you must notify EPA as 
specified in Sec. 141.35(c)(5).

                       Table 2--Monitoring Frequency by Contaminant and Water Source Types
----------------------------------------------------------------------------------------------------------------
          Contaminant type                Water source type             Time frame               Frequency
----------------------------------------------------------------------------------------------------------------
Chemical...........................  Surface water or ground      12 months.............  You must monitor for 4
                                      water under the direct                               consecutive quarters.
                                      influence of surface water                           Sample events must
                                      (GWUDI) (includes all                                occur 3 months apart.
                                      sampling locations for
                                      which some or all of the
                                      water comes from a surface
                                      water or GWUDI source at
                                      any time during the 12
                                      month monitoring period).
                                     Ground water...............  12 months.............  You must monitor twice
                                                                                           in a consecutive 12-
                                                                                           month period. Sample
                                                                                           events must occur 5-7
                                                                                           months apart.
----------------------------------------------------------------------------------------------------------------

    (C) Location. You must collect samples for each List 1 Assessment 
Monitoring contaminant, and, if applicable, for each List 2 Screening 
Survey, or List 3 Pre-Screen Testing contaminant, as specified in Table 
1, in paragraph (a)(3) of this section. Samples must be collected at 
each sample point that is specified in column 5 of Table 1, in paragraph 
(a)(3) of this section. If you are a ground water system with multiple 
EPTDSs, and you request and receive approval from EPA or the State for 
sampling at representative EPTDS(s), as specified in Sec. 141.35(c)(3), 
you must collect your samples from the approved representative sampling 
location(s). Systems conducting Screening Survey monitoring must also 
sample for nitrosamines at the disinfection byproduct distribution 
system maximum residence time (DSMRT) sampling location(s) if they are 
subject to sampling requirements in Sec. 141.132(b)(1).
    (D) Sampling instructions. For each List 1 Assessment Monitoring 
contaminant, and, if applicable, for each List 2 Screening Survey, or 
List 3 Pre-Screen Testing contaminant, you must follow the sampling 
procedure for the method specified in column 3 of Table 1, in paragraph 
(a)(3) of this section. In addition, you must not composite (that is, 
combine, mix, or blend) the samples; you must collect and preserve each 
sample separately. Samples collected

[[Page 430]]

for the analysis of Acetanilide ``parent'' pesticides and their 
degradation products (Methods 525.2 and 535) must be collected at the 
same sampling point, at the same time.
    (E) Sample collection and shipping time. If you must ship the 
samples for analysis, you must collect the samples early enough in the 
day to allow adequate time to send the samples for overnight delivery to 
the laboratory. You should not collect samples on Friday, Saturday, or 
Sunday because sampling on these days may not allow samples to be 
shipped and received at the laboratory at the required temperature, 
unless you have made special arrangements with your laboratory to 
receive the samples.
    (F) Analytical methods. For each contaminant, you must use the 
respective analytical methods for List 1, and, if applicable, for List 
2, or List 3 that are specified in column 3 of Table 1, in paragraph 
(a)(3) of this section; report values at or above the minimum reporting 
levels for List 1, and, if applicable, for List 2 Screening Survey, or 
List 3 Pre-Screen Testing, that are specified in column 4 of Table 1, in 
paragraph (a)(3) of this section; and conduct the quality control 
procedures specified in paragraph (a)(5) of this section.
    (G) Laboratory errors or sampling deviations. If the laboratory data 
do not meet the required QC criteria, as specified in paragraph (a)(5) 
of this section, or you do not follow the required sampling procedures, 
as specified in paragraphs (a)(4) of this section, you must resample 
within 30 days of being informed or becoming aware of these facts. This 
resampling is not for the purpose of confirming previous results, but to 
correct the sampling or laboratory error. All systems must report the 
results obtained from the first sampling for each sampling period, 
except for cases of sampling or laboratory errors. For the purposes of 
this rule, no samples are to be recollected for the purposes of 
confirming the results observed in a previous sampling.
    (H) Analysis. For the List 1 contaminants, and, if applicable, List 
2 Screening Survey, or List 3 Pre-Screen Testing contaminants, 
identified in Table 1, paragraph (a)(3) of this section, you must 
arrange for testing by a laboratory that has been approved by EPA 
according to requirements in paragraph (a)(5)(ii) of this section.
    (I) Review and reporting of results. After you have received the 
laboratory results, you must review, approve, and submit the system 
information, and sample collection data and test results. You must 
report the results as provided in Sec. 141.35(c)(6).
    (ii) Small systems. If you serve 10,000 or fewer people and are 
notified that you are part of the State Monitoring Plan for Assessment 
Monitoring, Screening Survey or Pre-Screen monitoring, you must comply 
with the requirements specified in paragraphs (a)(4)(i)(A) through (H) 
of this section. If EPA or the State informs you that they will be 
collecting your UCMR samples, you must assist them in identifying the 
appropriate sampling locations and in collecting the samples.
    (A) Monitoring period and frequency. You must collect samples at the 
times specified for you by the State or EPA. Your schedule must follow 
both the timing of monitoring specified in Table 1, List 1, and, if 
applicable, List 2, or List 3, and the frequency of monitoring in Table 
2 of this section.
    (B) Location. You must collect samples at the locations specified 
for you by the State or EPA.
    (C) Sample kits. You must store and maintain the sample collection 
kits sent to you by the UCMR Sampling Coordinator in accordance with the 
kit's instructions. The sample kit will include all necessary 
containers, packing materials and cold packs, instructions for 
collecting the sample and sample treatment (such as dechlorination or 
preservation), report forms for each sample, contact name and telephone 
number for the laboratory, and a prepaid return shipping docket and 
return address label. If any of the materials listed in the kit's 
instructions are not included in the kit or arrive damaged, you must 
notify the UCMR Sampling Coordinator who sent you the sample collection 
kits.
    (D) Sampling instructions. You must comply with the instructions 
sent to you by the State or EPA concerning the use of containers, 
collection (how to fill the sample bottle),

[[Page 431]]

dechlorination and/or preservation, and sealing and preparation of 
sample and shipping containers for shipment. You must not composite 
(that is, combine, mix, or blend) the samples. You also must collect, 
preserve, and test each sample separately. You must also comply with the 
instructions sent to you by the UCMR Sampling Coordinator concerning the 
handling of sample containers for specific contaminants.
    (E) Sampling deviations. If you do not collect a sample according to 
the instructions provided to you for a listed contaminant, you must 
report the deviation within 7 days of the scheduled monitoring on the 
sample reporting form, as specified in Sec. 141.35(d)(2). You must 
resample following instructions that you will be sent from the UCMR 
Sampling Coordinator or State. A copy of the form must be sent to the 
laboratory with the recollected samples, and to the UCMR Sampling 
Coordinator.
    (F) Duplicate samples. EPA will select a subset of systems in the 
State Monitoring Plan that must collect duplicate samples for quality 
control. If your system is selected, you will receive two sample kits 
for an individual sampling location that you must use. You must use the 
same sampling protocols for both sets of samples, following the 
instructions in the duplicate sample kit.
    (G) Sampling forms. You must completely fill out each of the 
sampling forms and bottles sent to you by the UCMR Sampling Coordinator, 
including data elements listed in Sec. 141.35(e) for each sample. If 
you are conducting Assessment Monitoring, you must include elements 1 
through 5, and 7; and if you are conducting Screening Survey, you must 
include elements 1 through 7. You must sign and date the sampling forms.
    (H) Sample collection and shipping. You must collect the samples 
early enough in the day to allow adequate time to send the samples for 
overnight delivery to the laboratory. You should not collect samples on 
Friday, Saturday, or Sunday because sampling on these days may not allow 
samples to be shipped and received at the laboratory at the required 
temperature unless you have made special arrangements with EPA for the 
laboratory to receive the samples. Once you have collected the samples 
and completely filled in the sampling forms, you must send the samples 
and the sampling forms to the laboratory designated on the air bill.
    (5) Quality control requirements. If your system serves more than 
10,000 people, you must ensure that the quality control requirements 
listed below are met during your sampling procedures and by the 
laboratory conducting your analyses. You must also ensure that all 
method quality control procedures and all UCMR quality control 
procedures are followed.
    (i) Sample collection/preservation. You must follow the sample 
collection and preservation requirements for the specified method for 
each of the contaminants in Table 1, in paragraph (a)(3) of this 
section. These requirements specify sample containers, collection, 
dechlorination, preservation, storage, sample holding time, and extract 
storage and/or holding time that you must assure that the laboratory 
follow.
    (ii) Laboratory approval for Lists 1, List 2 and List 3. To be 
approved to conduct UCMR testing, the laboratory must be certified under 
Sec. 141.28 for one or more compliance analyses; demonstrate for each 
analytical method it plans to use for UCMR testing that it can meet the 
Initial Demonstration of Capability (IDC) requirements detailed in the 
analytical methods specified in column 3 of Table 1, in paragraph (a)(3) 
of this section; and successfully participate in the UCMR Proficiency 
Testing (PT) Program administered by EPA for each analytical method it 
plans to use for UCMR testing. UCMR laboratory approval decisions will 
be granted on an individual method basis for the methods listed in 
column 3 of Table 1 in paragraph (a)(3) of this section for List 1, List 
2, and List 3 contaminants. Laboratory approval is contingent upon the 
capability of the laboratory to post monitoring data to the EPA 
electronic data reporting system. To participate in the UCMR Laboratory 
Approval Program, the laboratory must complete and submit the necessary 
registration forms by April 4, 2007. Correspondence must be addressed 
to: UCMR 2 Laboratory Approval Coordinator, USEPA, Technical Support 
Center, 26 West Martin Luther King Drive (MS 140), Cincinnati, OH 45268; 
or e-mailed to

[[Page 432]]

EPA at UCMR--Sampling--Coordinator@epa.gov.
    (iii) Minimum Reporting Level. The MRL is the lowest analyte 
concentration for which future recovery is predicted to fall, with high 
confidence (at least 99%), between 50% and 150% recovery.
    (A) Validation of laboratory performance. Your laboratory must be 
capable of quantifying each contaminant listed in Table 1, at or below 
the MRL specified in column 4 of Table 1, in paragraph (a)(3) of this 
section. You must ensure that the laboratory completes and has on file 
and available for your inspection, records of two distinct procedures. 
First, your laboratory must have conducted an IDC involving replicate 
analyses at or below the MRL as described in this paragraph. Second, for 
each day that UCMR analyses are conducted by your laboratory, a 
validation of its ability to quantify each contaminant, at or below the 
MRL specified in column 4 of Table 1, in paragraph (a)(3) of this 
section, following the procedure listed in paragraph (a)(5)(iii)(B) of 
this section, must be performed. The procedure for initial validation of 
laboratory performance at or below the MRL is as follows:
    (1) All laboratories using EPA drinking water methods under UCMR 
must demonstrate that they are capable of meeting data quality 
objectives (DQOs) at or below the MRL listed in Table 1, column 4, in 
paragraph (a)(3) of this section.
    (2) The MRL, or any concentration below the MRL, at which 
performance is being evaluated, must be contained within the range of 
calibration. The calibration curve regression model and the range of 
calibration levels that are used in these performance validation steps 
must be used in all routine sample analyses used to comply with this 
regulation. Only straight line or quadratic regression models are 
allowed. The use of either weighted or unweighted models is permitted. 
The use of cubic regression models is not permitted.
    (3) Replicate analyses of at least seven (7) fortified samples in 
reagent water must be performed at or below the MRL for each analyte, 
and must be processed through the entire method procedure (i.e., 
including extraction, where applicable, and with all preservatives).
    (4) A prediction interval of results (PIR), which is based on the 
estimated arithmetic mean of analytical results and the estimated sample 
standard deviation of measurement results, must be determined by 
Equation 1:
[GRAPHIC] [TIFF OMITTED] TR04JA07.000

Where:

t is the Student's t value with df degrees of freedom and confidence 
          level (1-[alpha]),
s is the sample standard deviation of n replicate samples fortified at 
          the MRL,
n is the number of replicates.

    (5) The values needed to calculate the PIR using Equation 1 are: 
Number of replicates (n); Student's t value with a two-sided 99% 
confidence level for n number of replicates; the average (mean) of at 
least seven replicates; and the sample standard deviation. Factor 1 is 
referred to as the Half Range PIR (HRPIR).
[GRAPHIC] [TIFF OMITTED] TR04JA07.001


For a certain number of replicates and for a certain confidence level in 
Student's t, this factor
[GRAPHIC] [TIFF OMITTED] TR04JA07.002


is constant, and can be tabulated according to replicate number and 
confidence level for the Student's t. Table 3 in this paragraph lists 
the constant factor (C) for replicate sample numbers

[[Page 433]]

7 through 10 with a confidence level of 99% for Student's t.

    (6) The HRPIR is calculated by Equation 2:
    [GRAPHIC] [TIFF OMITTED] TR04JA07.003
    
    (7) The PIR is calculated by Equation 3:
    [GRAPHIC] [TIFF OMITTED] TR04JA07.004
    

Table 3--The Constant Factor (C) to be Multiplied by the Standard Deviation to Determine the Half Range Interval
                                of the PIR (Student's t 99% Confidence Level) \a\
----------------------------------------------------------------------------------------------------------------
                                                                            Constant factor (C) to be multiplied
             Replicates                        Degrees of freedom                by the standard  deviation
----------------------------------------------------------------------------------------------------------------
                               7                                     6                                 3.963
----------------------------------------------------------------------------------------------------------------
                               8                                     7                                 3.711
----------------------------------------------------------------------------------------------------------------
                               9                                     8                                 3.536
----------------------------------------------------------------------------------------------------------------
                              10                                     9                                3.409
----------------------------------------------------------------------------------------------------------------
\a\ The critical t-value for a two-sided 99% confidence interval is equivalent to the critical t-value for a one-
  sided 99.5% confidence interval, due to the symmetry of the t-distribution. PIR = Prediction Interval of
  Results.

    (8) The lower and upper result limits of the PIR must be converted 
to percent recovery of the concentration being tested. To pass criteria 
at a certain level, the PIR lower recovery limits cannot be lower than 
the lower recovery limits of the QC interval (50%), and the PIR upper 
recovery limits cannot be greater than the upper recovery limits of the 
QC interval (150%). When either of the PIR recovery limits falls outside 
of either bound of the QC interval of recovery (higher than 150% or less 
than 50%), laboratory performance is not validated at the concentration 
evaluated. If the PIR limits are contained within both bounds of the QC 
interval, laboratory performance is validated for that analyte.
    (B) Quality control requirements for validation of laboratory 
performance at or below the MRL.
    (1) You must ensure that the calibration curve regression model and 
that the range of calibration levels that are used in these performance 
validation steps are used in future routine sample analysis. Only 
straight line or quadratic regression models are allowed. The use of 
either weighted or unweighted models is permitted. The use of cubic 
regression models is not permitted.
    (2) You must ensure, once your laboratory has performed an IDC as 
specified in each analytical method (demonstrating that DQOs are met at 
or below an MRL), that a daily performance check is performed for each 
analyte and method. A single laboratory blank, fortified at or below the 
MRL for each analyte, must be processed through the entire method 
procedure. The measured concentration for each analyte must be converted 
to a percent recovery, and if the recovery is within 50%-150% 
(inclusive), the daily performance of the laboratory has been validated. 
The results for any analyte for which 50%-150% recovery cannot be 
demonstrated during the daily check are not valid. Laboratories may 
elect to re-run the daily performance check sample if the performance 
for any analyte or analytes cannot be validated. If performance is 
validated for these analytes, the laboratory performance is considered 
validated. Alternatively, the laboratory may re-calibrate and repeat the 
performance validation process for all analytes.
    (iv) Laboratory fortified sample matrix and laboratory fortified 
sample matrix duplicate. You must ensure that your laboratory prepares 
and analyzes the Laboratory Fortified Sample Matrix (LFSM) sample for 
accuracy and Laboratory Fortified Sample Matrix Duplicate (LFSMD) 
samples for precision to determine method accuracy and precision for all 
contaminants in Table 1, in paragraph (a)(3) of this section. LFSM/LFSMD 
samples must be prepared using a sample collected and analyzed

[[Page 434]]

in accordance with UCMR 2 requirements and analyzed at a frequency of 5% 
(or 1 LFSM/LFSMD set per every 20 samples) or with each sample batch, 
whichever is more frequent. In addition, the LFSM/LFSMD fortification 
concentrations must be alternated between a low-level fortification and 
mid-level fortification approximately 50% of the time. (For example: A 
set of 40 samples will require preparation and analysis of 2 LFSM/LFSMD 
sets. The first set must be fortified at either the low-level or mid-
level, and the second set must be fortified with the other standard, 
either the low-level or mid-level, whichever was not used for the 
initial LFSM/LFSMD set.) The low-level LFSM/LFSMD fortification 
concentration must be within 50% of the MRL for 
each contaminant (e.g., for an MRL of 1 [mu]g/L the acceptable 
fortification levels must be between 0.5 [mu]g/L and 1.5 [mu]g/L). The 
mid-level LFSM/LFSMD fortification concentration must be within 20% of the mid-level calibration standard for each 
contaminant, and should represent, where possible and where the 
laboratory has data from previously analyzed samples, an approximate 
average concentration observed in previous analyses of that analyte. 
There are no acceptance criteria specified for LFSM/LFSMD analyses. All 
LFSM/LFSMD data are to be reported.
    (v) Method defined quality control. You must ensure that your 
laboratory performs Laboratory Fortified Blanks and Laboratory 
Performance Checks, as appropriate to the method's requirements, for 
those methods listed in Table 1, column 3, in paragraph (a)(3) of this 
section. Each method specifies acceptance criteria for these QC checks.
    (vi) Reporting. You must ensure that your laboratory reports the 
analytical results and other data, with the required data listed in 
Table 1, in Sec. 141.35(e). You must require your laboratory to submit 
these data electronically to the State and EPA using EPA's electronic 
data reporting system, accessible at (http://www.epa.gov/safewater/ucmr/
ucmr2/reporting.html), within 120 days from the sample collection date. 
You then have 60 days from when the laboratory posts the data to review, 
approve, and submit the data to the State and EPA, via EPA's electronic 
data reporting system. If you do not electronically approve and submit 
the laboratory data to EPA within 60 days of the laboratory's posting to 
EPA's electronic reporting system, the data will be considered approved 
and final for State and EPA review.
    (6) Violation of this rule--(i) Monitoring violations. Any failure 
to monitor in accordance with Sec. 141.40(a)(3)-(5) is a monitoring 
violation.
    (ii) Reporting violations. Any failure to report in accordance with 
Sec. 141.35 is a reporting violation.
    (b) Petitions and Waivers by States--(1) Governors' petition for 
additional contaminants. The Safe Drinking Water Act allows Governors of 
seven (7) or more States to petition the EPA Administrator to add one or 
more contaminants to the UCMR Contaminant List in paragraph (a)(3) of 
this section. The petition must clearly identify the reason(s) for 
adding the contaminant(s) to the monitoring list, including the 
potential risk to public health, particularly any information that might 
be available regarding disproportional risks to the health and safety of 
children, the expected occurrence documented by any available data, any 
analytical methods known or proposed to be used to test for the 
contaminant(s), and any other information that could assist the 
Administrator in determining which contaminants present the greatest 
public health concern and should, therefore, be included on the UCMR 
Contaminant List in paragraph (a)(3) of this section.
    (2) State-wide waivers. A State can waive monitoring requirements 
only with EPA approval and under very limited conditions. Conditions and 
procedures for obtaining a waiver are as follows:
    (i) Application. A State may apply to EPA for a State-wide waiver 
from the unregulated contaminant monitoring requirements for PWSs 
serving more than 10,000 people. To apply for such a waiver, the State 
must submit an application to EPA that includes the following 
information: The list of contaminants on the UCMR Contaminant List for 
which a waiver is requested, along with documentation for each

[[Page 435]]

contaminant in the request demonstrating that the contaminants or their 
parent compounds do not occur naturally in the State, and certifying 
that during the past 15 years they have not been used, applied, stored, 
disposed of, released, or detected in the source waters or distribution 
systems in the State.
    (ii) Approval. EPA will review State applications and notify the 
State whether it accepts or rejects the request. The State must receive 
written approval from EPA before issuing a State-wide waiver.

[72 FR 393, Jan. 4, 2007; 72 FR 3916, Jan. 26, 2007]