Public Meeting and Webinar: 

Revisions to the Unregulated Contaminant 

Monitoring Rule (UCMR 4)

Meeting Presentations

Held June 25, 2014

USEPA, Office of Ground Water and Drinking Water

Office of Water (MLK 140) EPA 815-A-14-001 June 2014
Revisions to the Unregulated 

Contaminant Monitoring Rule 

(UCMR 4) for Public Water Systems 

Public Meeting and Webinar

June 25th, 2014

Meeting starts at 9:00 a.m. E.T.

USEPA 

Office of Ground Water and Drinking Water

June 25, 2014 U.S. Environmental Protection Agency 1 

June 25, 2014 U.S. Environmental Protection Agency 2 

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Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 2
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WELCOME

Revisions to the Unregulated 

Contaminant Monitoring Rule 

(UCMR 4) for Public Water Systems

Public Stakeholder Meeting 

and Webinar

June 25, 2014 U.S. Environmental Protection Agency 6 

• Purpose

o Review the status of EPA’s efforts in the areas of analyte

selection, analytical methods, sampling design, determination of 

minimum reporting levels, and other possible revisions relative 

to the rule

• Webinar lines are muted to minimize background noise. 

• On-site attendees: 

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registration table.

General Meeting Information

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 3
June 25, 2014 U.S. Environmental Protection Agency 7 

Agenda

8:30-9:00 Stakeholder Sign-in

9:00-9:20 Welcome – Introduction and Agenda

9:20-9:50 Overview of the UCMR Program

9:50-10:30 UCMR 3 Status

10:30-10:45 BREAK

10:45-11:30 UCMR 4 Potential Sampling Design Change Relative to UCMR 3

11:30-11:45 Discussion

11:45-1:15 LUNCH

1:15-3:00 UCMR 4 Candidate Selections and Rationale

3:00-3:15 BREAK

3:15-3:45 Approval of Laboratories Supporting UCMR 4

3:45-5:00 Discussion

8

Overview of the Unregulated 

Contaminant Monitoring Program

Brenda Parris

USEPA, OGWDW, SRMD

Technical Support Center

Cincinnati, Ohio

Public Meeting and Webinar

Washington D.C.

June 25th, 2014 – 9:20 a.m.

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 4
Overview

• Unregulated Contaminant Monitoring (UCM) 

program 

• Regulatory background for UCMR

− Safe Drinking Water Act (SDWA) authority

− Relationship to Contaminant Candidate List (CCL)

• Unregulated Contaminant Monitoring Rule 

(UCMR) approach

− UCMR cycles

− UCMR implementation

June 25, 2014 U.S. Environmental Protection Agency 9 

Safe Drinking Water Act

• Passed in 1974, amended in 1986 and 1996

• Authorized EPA to set enforceable health 

standards for contaminants in drinking water 

– National Primary Drinking Water Standards 

(NPDWS)

• Outlined a sound science approach to 

NPDWS development that required 

consideration of: 

− Occurrence Data

− Health Effects Data

− Cost Benefit Analysis

June 25, 2014 U.S. Environmental Protection Agency 10

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 5
Unregulated Contaminant 

Monitoring

• 1986 SDWA amendments were the basis for 

the original UCM program

• UCM Rounds 1 (1988-1992, 62 contaminants) 

& 2 (1993-1997, 48 contaminants) 

– State drinking water programs managed the 

original UCM program

– Public water systems (PWSs) serving > 500 people 

were required to monitor

June 25, 2014 U.S. Environmental Protection Agency 11

Safe Drinking Water Act

• 1996 SDWA amendments changed the 

process of developing and reviewing NPDWS

– Contaminant Candidate List 

– Unregulated Contaminant Monitoring Rule

– Regulatory Determination

– Six-Year Review

June 25, 2014 U.S. Environmental Protection Agency 12

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 6
General Flow of Regulatory Process

June 25, 2014 U.S. Environmental Protection Agency 13

Draft CCL 

Final CCL 

Final Rule 

(NPDWR) 

Six Year Review of 

Existing NPDWRs 

No further action if make 

decision not to regulate (may 

develop health advisory). 

Preliminary 

Regulatory 

Determinations 

Final Regulatory 

Determinations 

Proposed Rule 

(NPDWR) Draft UCMR 

Final UCMR 

UCMR Monitoring 

Results 

At each stage, need increased specificity and confidence in the type of 

supporting data used (e.g. health and occurrence). 

Contaminant Candidate List

June 25, 2014 U.S. Environmental Protection Agency 14

• SDWA requires EPA to list unregulated 

contaminants that may require a national 

drinking water regulation in the future

• Every five years CCL defines unregulated 

contaminants for which EPA needs

– Occurrence data

– Analytical methods

– Potential health effects

– Evaluation of treatment techniques

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 7
Contaminant Candidate List

• EPA considered approximately 7,500 potential chemical 

and microbial contaminants

• Screening process based on a contaminant’s potential to 

occur in public water systems (PWSs) and the potential for 

public health concerns

• Further detailed evaluations, public input, and expert 

judgment and review are used in the final contaminant 

selection

• Final CCL 3 published October 8, 2009

– 104 chemicals or chemical groups and 12 microbiological 

contaminants

• CCL 4 is in development

June 25, 2014 U.S. Environmental Protection Agency 15

Unregulated Contaminant Monitoring Rule

• 1996 Safe Drinking Water Act Amendments

– Redesigned the UCM program and included these 

requirements:

• Monitor no more than 30 contaminants per 5-year cycle

• Monitor only a representative sample of PWSs serving 

10,000 or fewer people

• Store analytical results in the National Contaminant 

Occurrence Database (NCOD)

• Direct implementation – EPA managed program in 

partnership with States

• EPA funds testing/analytical costs for small PWSs

June 25, 2014 U.S. Environmental Protection Agency 16

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 8
Objective of UCMR Program

• Develop a list of contaminants, largely based on CCL, 

every five years

• Collect occurrence data for suspected drinking water 

contaminants that do not have health-based standards 

set under SDWA

• Occurrence information is used to support future 

regulatory decision-making

• Supports the Administrator’s determination of whether 

(or not) to regulate a contaminant under the drinking 

water program

June 25, 2014 U.S. Environmental Protection Agency 17

Unregulated Contaminant Monitoring Rule

• UCMR groups contaminants into three tiers 

based on their priority and analytical 

methodologies

– Assessment Monitoring (List 1)

– Employs commonly used analytical techniques 

– Screening Survey (List 2)

– Uses more recently developed analytical techniques

– Pre-Screen Testing (List 3)

– Utilizes new or specialized techniques

June 25, 2014 U.S. Environmental Protection Agency 18

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 9
UCMR 1

• UCMR 1 (2001-2005, 26 contaminants)

– Published in Federal Register (FR) on 

September 17, 1999

– Required all large PWSs and a nationally 

representative sample of small PWSs serving 

10,000 people to monitor for contaminants on 

List 1

– Required a random selection of 300 large and 

small PWSs to monitor for contaminants on List 2

June 25, 2014 U.S. Environmental Protection Agency 19

UCMR 2

• UCMR 2 (2007-2011, 25 contaminants)

– Published in Federal Register (FR) on 

January 4, 2007

– More PWSs included under List 2 

Screening Survey than for UCMR 1 to 

provide more representative results

– Define monitoring schedules to improve 

compliance

June 25, 2014 U.S. Environmental Protection Agency 20

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 10
UCMR 3

• UCMR 3 (2012-2016, 30 contaminants)

– Currently ongoing - monitoring ends in 

2015, data review will occur in 2016

– Published in Federal Register (FR) on 

April 16, 2012

June 25, 2014 U.S. Environmental Protection Agency 21

UCMR Implementation

• OGWDW, SRMD, Technical Support Center 

(Cincinnati)

– Review and track PWS applicability and monitoring 

progress

– Coordinate Laboratory Approval Program

– Provide technical support for Regions, States, 

PWSs and laboratories

– Coordinate outreach

– Assist and support Regional compliance efforts

June 25, 2014 U.S. Environmental Protection Agency 22

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 11
UCMR Implementation

• OGWDW, SRMD, Technical Support Center 

(Cincinnati)

– Small PWS support

– Maintain lab and implementation contracts to support UCMR

– Manage sample kit distribution

– Responsible for data review and reporting

– Prepare data for NCOD

– Large PWS support

– Extract data from the Safe Drinking Water Accession and Review 

System (SDWARS) for evaluation and reporting to NCOD

– Support SDWARS reporting system and users

June 25, 2014 U.S. Environmental Protection Agency 23

Extended UCMR Implementation Team

• OGWDW, DWPD, Infrastructure Branch

– Responsible for SDWARS

• EPA Regional Offices

– Coordinate State partnership agreements 

– Assist States and PWSs with UCMR 

requirements, compliance and enforcement

• Partnering States

– Support various levels of monitoring coordination

June 25, 2014 U.S. Environmental Protection Agency 24

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 12
25

Status of the Third Unregulated 

Contaminant Monitoring Rule 

(UCMR 3)

Public Meeting and Webinar

Washington D.C.

June 25th, 2014 – 9:50 a.m.

Gregory J. Carroll

USEPA, OGWDW, SRMD

Technical Support Center

Cincinnati, Ohio

Overview

• Timing, Activities and Applicability

• Monitoring

– List 1, List 2, List 3

• Reporting

– Current Status

• Occurrence Data

– NCOD

• Preparation for UCMR 4

June 25, 2014 U.S. Environmental Protection Agency 26

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 13
Time Line of UCMR 3 Activities

June 25, 2014 U.S. Environmental Protection Agency 27

2012 2013 2014 2015 2016

Pre-monitoring 

Implementation

• Lab Approval

• Notifications

• SDWARS 

Registration

• Inventory

• Schedule

Sampling and Reporting Period

One consecutive 12-month period during 

January 2013 - December 2015 (monitoring 

can span more than one calendar year, as long 

as conducted during a consecutive 12-month 

period).

Post-monitoring 

Phase

• Complete 

Resampling

• Conclude Data 

Reporting

• Finalize NCOD

• Continue 

Enforcement

System Definitions and Sizes

• Public water system (PWS) provides water for human consumption 

through pipes or other constructed conveyances to at least 15 service 

connections or serves an average of at least 25 people for at least 60 

days a year.

– Community Water System (CWS) supplies water to the same population 

year-round.

– Non-Transient Non-Community Water System (NTNCWS) regularly 

supplies water to at least 25 of the same people at least six months per 

year, but not year-round. Examples include schools, factories, office 

buildings, and hospitals that have their own water systems.

– Transient Non-Community Water System (TNCWS) provides water in a 

place such as a gas station or campground where people do not remain 

for long periods of time.

June 25, 2014 U.S. Environmental Protection Agency 28

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 14
UCMR 3 System Applicability

Assessment Monitoring (List 1 Contaminants)

System Type Systems Serving > 10,000 Systems Serving ≤ 10,000

CWS & NTNCWS All systems (~4,200) 800 randomly selected systems

TNCWS No requirements No requirements

Screening Survey (List 2 Contaminants)

System Type Systems Serving > 10,000 Systems Serving ≤ 10,000

CWS & NTNCWS

All systems(~410) serving more 

than 100,000, and ~320 randomly 

selected systems serving 10,001 to 

100,000

480 randomly selected systems

TNCWS No requirements No requirements

Pre-Screen Testing (List 3 Contaminants)

System Type Systems Serving > 1,000 Systems Serving ≤ 1,000

CWS, TNCWS & NTNCWS No requirements 800 randomly selected systems

June 25, 2014 U.S. Environmental Protection Agency 29

UCMR 3 Monitoring

• PWSs must monitor during a consecutive 

12-month period between 2013 - 2015

• Number of times a PWS samples is directly 

related to the sample point source

– Surface water and ground water under the direct 

influence of surface water – must monitor quarterly 

during their 12-month schedule (sample three 

months apart)

– Ground water – must monitor twice during their 

12-month schedule (sample five to seven 

months apart)

June 25, 2014 U.S. Environmental Protection Agency 30

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 15
UCMR 3 Monitoring Lists

• Assessment Monitoring (List 1 Contaminants) relies on 

common analytical method technologies used by drinking water 

laboratories

• Screening Survey (List 2 Contaminants) monitoring uses more 

specialized analytical method technologies

• Pre-Screen Testing (List 3 Contaminants) relies on newer 

method technologies not as commonly used by drinking water 

laboratories

UCMR 3 Pre-Screen Testing involves ground water systems that:

– Serve less than 1,000 people

– Do not disinfect

– Are located in vulnerable areas of karst or fractured bedrock

June 25, 2014 U.S. Environmental Protection Agency 31

UCMR 3 Sampling Locations

Contaminant Type Sampling Location Type

Assessment Monitoring: List 1 Contaminants

Volatile Organic Compounds EPTDS

Synthetic Organic Compound (1,4-dioxane) EPTDS

Perfluorinated Compounds EPTDS

Oxyhalide Anion (chlorate) EPTDS and DSMRT

Metals EPTDS and DSMRT

Chromium-6 EPTDS and DSMRT

Screening Survey: List 2 Contaminants

Hormones EPTDS

Pre-Screen Testing: List 3 Contaminants

Viruses EPTDS

June 25, 2014 U.S. Environmental Protection Agency 32

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 16
UCMR 3 List 1 Contaminants

Assessment Monitoring: List 1 Contaminants MRL 

(μg/L)

Volatile Organic Compounds – EPA Method 524.3

chloromethane (methyl chloride) 0.2 

bromomethane (methyl bromide) 0.2 

chlorodifluoromethane (HCFC-22) 0.08 

bromochloromethane (halon 1011) 0.06 

1,1-dichloroethane 0.03 

1,2,3-trichloropropane 0.03 

1,3-butadiene 0.1 

Synthetic Organic Compound – EPA Method 522

1,4-dioxane 0.07

EPA will pay for all analytical and shipping costs associated with List 1 monitoring at small systems (< 10,000). 

June 25, 2014 U.S. Environmental Protection Agency 33

UCMR 3 List 1 Contaminants

Assessment Monitoring: List 1 Contaminants MRL 

(μg/L)

Perfluorinated Compounds– EPA Method 537

perfluorooctane sulfonic acid (PFOS) 0.04 

perfluorooctanoic acid (PFOA) 0.02 

perfluorononanoic acid (PFNA) 0.02 

perfluorohexane sulfonic acid (PFHxS) 0.03 

perfluoroheptanoic acid (PFHpA) 0.01 

perfluorobutanesulfonic acid (PFBS) 0.09 

Oxyhalide Anion – EPA Method 300.1; SM 4110D; ASTM D658-08

chlorate 20

EPA will pay for all analytical and shipping costs associated with List 1 monitoring at small systems (< 10,000). 

June 25, 2014 U.S. Environmental Protection Agency 34

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 17
UCMR 3 List 1 Contaminants

Assessment Monitoring: List 1 Contaminants MRL 

(μg/L)

Metals – EPA Method 200.8; SM 3125; ASTM D5763-10

cobalt 1

molybdenum 1

strontium 0.3 

vanadium 0.2 

chromium 0.2 

Chromium-6 – EPA Method 218.7

chromium-6 0.03 

EPA will pay for all analytical and shipping costs associated with List 1 monitoring at small systems (< 10,000). 

June 25, 2014 U.S. Environmental Protection Agency 35

UCMR 3 List 2 Contaminants 

Screening Survey: List 2 Contaminants MRL 

(μg/L)

Hormones – EPA Method 539

17-β-estradiol 0.0004 

17-α-ethynylestradiol (ethinyl estradiol) 0.0009 

16-α-hydroxyestradiol (estriol) 0.0008 

equilin 0.004 

estrone 0.002 

testosterone 0.0001 

4-androstene-3,17-dione 0.0003 

EPA will pay for all analytical and shipping costs associated with List 2 monitoring at small systems (< 10,000). 

June 25, 2014 U.S. Environmental Protection Agency 36

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 18
UCMR 3 List 3 Contaminants 

Pre-Screen Testing: List 3 Contaminants Detection Assay

Microbiological Contaminants – EPA Method 1615

enterovirus Cell culture; qPCR

norovirus qPCR

Microbiological Indicators

total coliforms

E. coli

Enterococci

bacteriophage

aerobic spores

EPA will collect the samples from List 3 sampling locations, and will pay for all analytical and shipping costs associated with 

viruses and indicators at these small systems (< 1,000).

June 25, 2014 U.S. Environmental Protection Agency 37

UCMR 3 Responsibilities

• Small PWSs serving 10,000 or fewer people 

are not responsible for the costs associated 

with analyses and shipping

– EPA engages States and PWSs to collect samples 

for List 1 and List 2

– EPA collects samples for List 3

– EPA coordinates sample analyses with contracted 

laboratories and funds the analyses

– EPA examines the results along with quality control 

data and generates reports

June 25, 2014 U.S. Environmental Protection Agency 38

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 19
UCMR 3 Responsibilities

• Large PWSs serving more than 10,000 people 

are responsible for the costs associated with 

analyses

– PWS coordinates sample analyses with an 

approved laboratory

– Laboratories post the data to the Safe Drinking 

Water Accession and Review System (SDWARS 3)

– PWS reviews and can act upon 

(e.g., approve) data in SDWARS 3

States and EPA review results

June 25, 2014 U.S. Environmental Protection Agency 39

UCMR 3 Occurrence Data

– Updated quarterly and posted in the National 

Contaminant Occurrence Database (NCOD)

– Quarterly updates can be accessed from

– http://water.epa.gov/lawsregs/rulesregs/sdwa/ucmr/data.cfm#

ucmr2013 

– Zipped file contains a summary document (PDF), occurrence 

data (.txt), disinfectant residual type (.txt) and U.S. postal 

service zip code(s) for all areas served by a PWS (.txt)

– Data will continue to be added and may be corrected 

on further review

– Use caution when interpreting the data before the dataset is 

complete (mid-late 2016)

June 25, 2014 U.S. Environmental Protection Agency 40

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 20
UCMR 3 Results To-Date

• OGWDW posted PWS results (submitted through 

April 2014) to the web (NCOD)

• Chemicals are studied at levels that are often 

significantly below those in previous UCMRs

• The detection of a UCMR 3 analyte above the MRL 

does not represent cause for concern, in and of itself

• The data should be judged considering health 

effects information (reference concentration)

June 25, 2014 U.S. Environmental Protection Agency 41

UCMR 3 Preliminary Results

• ~3500 sample results from ~400 PWSs for 

hormones 

• ~18,000 sample results from ~1900 PWSs for 

metals, chlorate 

• ~11,000 sample results from 1800-1900 PWSs 

for other chemicals 

• ~1/3 of data that will ultimately be collected 

June 25, 2014 U.S. Environmental Protection Agency 42

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 21
Preliminary Data Summary Points 

• Metals

– Many PWSs had detections of metals (i.e., above the 

MRL)

– Between 0-3% of sample results were above the 

Reference Concentration (Ref Conc)

– Vanadium above the Ref Conc at ~3% of PWSs; strontium 

above the Ref Conc at 1%; other metals measured above 

the Ref Conc by less than 1% of PWSs

• Chlorate

– Many of the PWSs (~10,000 of ~18,000) had detections of 

chlorate

– 35% of the PWSs had chlorate measurements above the 

Ref Conc

June 25, 2014 U.S. Environmental Protection Agency 43

Preliminary Data Summary Points 

• 1,4-dioxane

– ~400 of ~1800 PWSs had detections of 1,4-dioxane 

– ~7% above the 10-6 Ref Conc of 0.35 μg/L; none 

above the 10-4 Ref Conc of 35 μg/L 

• Volatile Organic Compounds (VOCs) 

– One or more VOCs detected by 104 of the ~1800 

PWSs that reported data 

– Relatively few VOC measurements above the Ref 

Conc 

– 1,2,3-trichloropropane measured by ~1.4% of PWSs 

above the 10-4 Ref Conc; detected above MRL by 

~1.7% (MRL > 10-6 Ref Conc) 

June 25, 2014 U.S. Environmental Protection Agency 44

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 22
Preliminary Data Summary Points 

– Perfluorinated Compounds (PFCs)

• 36 of the ~1900 PWSs detected one or more PFCs

• 6 PWSs measured PFOS above the Ref Conc

• Ref Conc currently only available for PFOA and PFOS

– Hormones

• 17 of the ~400 PWSs detected one or more 

hormones

• Ref Conc available for the 5 estrogenic hormones, not 

the 2 androgenic hormones

• None of the PWSs had (estrogenic) hormone 

measurements above the Ref Conc

June 25, 2014 U.S. Environmental Protection Agency 45

Preliminary Virus Data

– Pre-Screen Testing at 800 small GW systems for 

norovirus, enterovirus, and “indicator” organisms

– Field samples collected from ~376 PWSs; data 

available for ~173 

• 133 indicator detections

– 26 enterococci

– 9 bacteriophage

– 84 aerobic spores

– 2 E. coli

– 12 total coliform

• 3 norovirus detections

June 25, 2014 U.S. Environmental Protection Agency 46

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 23
Timing for UCMR 3 and UCMR 4

• UCMR 3 monitoring activities are scheduled to 

end in December 2015

• UCMR 3 data will be finalized in 2016

• EPA anticipates proposing UCMR 4 in mid 

2015 

• UCMR 4 is anticipated to be final in late 2016 

• Implementation activity for UCMR 4 expected 

to begin in 2017 with monitoring expected to 

begin in January 2018

June 25, 2014 U.S. Environmental Protection Agency 47

June 25, 2014 U.S. Environmental Protection Agency 48

Revisions to the Unregulated 

Contaminant Monitoring Rule 

(UCMR 4) for Public Water Systems

Public Stakeholder Meeting 

and Webinar

Morning Break

Resume at 10:45 a.m.

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 24
49

UCMR 4

Potential Sampling Design Changes 

Relative to UCMR 3

Public Meeting and Webinar

Washington D.C.

June 25th, 2014 – 10:45 a.m.

Brenda Parris

USEPA, OGWDW, SRMD

Technical Support Center

Cincinnati, OH

Overview

• Background for the Unregulated Contaminant 

Monitoring Rule (UCMR) sampling design

• UCMR 4 sampling design considerations

• Approach to tiered monitoring

– Assessment Monitoring (List 1)

– Screening Survey (List 2)

– Pre-Screen Testing (List 3)

• Potential changes between UCMR 3 and 

UCMR 4

• Implementation considerations

June 25, 2014 U.S. Environmental Protection Agency 50

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 25
UCMR Background

• UCMR program designed for Safe Drinking Water 

Act (SDWA) specifications 

• Under §1445(a)(2)(A) of SDWA, as amended in 

1996, EPA required to:

– “vary the frequency and schedule for monitoring ...based 

on the number of persons served by the system, the 

source of supply, and the contaminants likely to be found;”

– ensure “that only a representative sample of systems 

serving 10,000 persons or fewer are required to monitor;” 

and 

– “pay the reasonable cost of such testing and laboratory 

analysis...” for small systems

June 25, 2014 U.S. Environmental Protection Agency 51

PWS Types

• Community water system

– Public Water System (PWS) that supplies water to 

the same population year-round

• Non-transient non-community water system

– PWS that supplies water to at least 25 of the same 

people at least six months per year, but not yearround

– Schools

• Transient non-community water system

– PWS that provides water where people do not 

remain for long periods of time

– Gas stations and campgrounds

June 25, 2014 U.S. Environmental Protection Agency 52

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 26
PWS Sizes

• Small PWSs serve 10,000 people or less

• Large PWSs serve 10,001-100,000 people

• “Extra large” PWSs serve over 100,001 

people

June 25, 2014 U.S. Environmental Protection Agency 53

Sampling Design Considerations

• UCMR 4 expected to be based on the 

sampling and statistical design used in 

UCMR 1, 2 and 3

– Vetted with stakeholders

– Peer reviewed

– Three rounds of public comment

June 25, 2014 U.S. Environmental Protection Agency 54

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 27
Sampling Design Considerations

Data Quality Objectives

• Unbiased national exposure estimates; small margin 

of error

• Account for differential occurrence

• Stratify across system size and source water type to 

account for differences

• Multiple sample events over multiple years to address 

temporal variability

• Allocation across states proportional to population 

served; at least two per state

June 25, 2014 U.S. Environmental Protection Agency 55

Assessment Monitoring

(List 1): Statistical Approach

• Expect to maintain same statistical design for 

Assessment Monitoring used in UCMR 1, 2 and 3

– Nationally representative sample of 800 small systems

– Census of large water systems

• Small system statistical sample combined with 

large system census data provides a powerful tool 

for assessing contaminant occurrence

June 25, 2014 U.S. Environmental Protection Agency 56

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 28
Sample Allocation for Small Systems in 

Assessment Monitoring (List 1)

Size Category Ground Water 

Systems

Surface Water 

Systems Total

500 and under 85 10 95

501 to 3,300 223 83 306

3,301 to 10,000 220 179 399

Total 528 272 800

June 25, 2014 U.S. Environmental Protection Agency 57

Screening Survey (List 2): 

Statistical Approach

• Designed to ensure the data can be used to 

support regulatory determinations and rule 

development (if warranted)

• Account for possible laboratory capacity issues 

related to use of recently developed or 

technically complex methods

June 25, 2014 U.S. Environmental Protection Agency 58

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 29
Screening Survey (List 2):

Statistical Approach

• Considering similar approach as UCMR 2 and 3:

– National sample of 800 systems, allocated across 

systems serving 100,000 or fewer:

– Small system (serving 10,000 or fewer) sample would not 

overlap with Assessment Monitoring

– Sample again allocated across strata of system size and source 

water type 

– Census of all systems serving 100,001 and over 

(~400 systems)

– Adds further confidence in the sampling results by including a 

census of the largest systems

• Total number of systems ~1,200

June 25, 2014 U.S. Environmental Protection Agency 59

UCMR Pre-Screen Testing (List 3)

• Envisioned for use with methods that are in the early 

stages of development, and/or very specialized (such 

as those for viruses or DNA/microchips)

• May be conducted by limited number of PWSs 

identified as vulnerable (by EPA and/or State 

agencies) 

• Not currently anticipated to be utilized for UCMR 4

June 25, 2014 U.S. Environmental Protection Agency 60

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 30
UCMR 4 Implementation Considerations

• The same sampling frequency used in UCMR 3 for 

Assessment Monitoring (AM) and Screening Survey 

(SS) is expected to be utilized for the majority of 

potential UCMR 4 analytes 

– Surface water systems (including groundwater under the 

direct influence of surface water) would sample four times 

during their year of monitoring

– Ground water systems would sample two times during their 

year of monitoring

• Considering altering the sampling frequency for 

selected AM and/or SS analytes in UCMR 4

June 25, 2014 U.S. Environmental Protection Agency 61

June 25, 2014 U.S. Environmental Protection Agency 62

• Selective monitoring for List 1 and 2 contaminants, such as

cyanotoxins and pesticides?

– UCMR 3: Selective monitoring was conducted with List 3 viruses but 

has not been conducted with List 1 or 2 contaminants

– UCMR 4 potential change: Target the monitoring of cyanotoxins and 

potentially pesticides by sampling in the warmer months of the year 

and only sampling surface water or ground water under the direct 

influence of surface water?

– Reason for considering change: 

– To obtain more accurate occurrence data on contaminants whose 

concentrations fluctuate

– Target timeframes when the contaminant is most likely to found, 

vulnerable period(s)

Potential Change Between 

UCMR 3 and UCMR 4: Monitoring

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 31
UCMR 4 Implementation Considerations

• Same monitoring schedule anticipated for AM 

and SS

– Months assigned to ensure coverage of temporal 

vulnerability and variability

– System monitoring spread across 3-year period to 

provide temporal coverage and to accommodate 

lab capacity 

• Year and months of monitoring assigned to small systems

• Large systems can re-define their year and month(s) of 

monitoring

June 25, 2014 U.S. Environmental Protection Agency 63

June 25, 2014 U.S. Environmental Protection Agency 64

Potential Change Between 

UCMR 3 and UCMR 4: Monitoring

• Reduce the period of UCMR monitoring?

– UCMR 3: 3 years were allocated for sample 

monitoring 

– UCMR 4 potential change: Compress the 

monitoring period to 2 years?

– Reason for considering change: 

– UCMR data would be available earlier to support 

regulatory determinations

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 32
UCMR 4 Implementation Considerations

• Sampling locations for potential AM and SS 

chemicals

– All chemicals would be sampled at the entry points 

to the distribution systems (EPTDSs)

– Metals, if any, would also be sampled at the 

distribution maximum residence time (DSMRT) 

location in the distribution systems

– Some adjustment in sampling locations may be 

warranted depending on the final selection of 

UCMR 4 contaminants

June 25, 2014 U.S. Environmental Protection Agency 65

June 25, 2014 U.S. Environmental Protection Agency 66

• Collect additional quality control (QC) data in SDWARS?

– UCMR 3: EPA collects more extensive small system QC data 

from contract laboratories, large systems report limited QC data

– UCMR 4 potential change: Require similar QC data to be 

submitted for both large and small systems?

– Reason for considering change: 

– Ensure a more robust dataset

Potential Change Between 

UCMR 3 and UCMR 4: QC Data

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 33
June 25, 2014 U.S. Environmental Protection Agency 67

• Improve SDWARS reporting functionality?

– UCMR 3: Compliance reports offer a summary of the reporting

status of individual PWSs and if they have fulfilled their

monitoring requirements

– UCMR 4 potential change: Update the functionality of

SDWARS to include compliance reports for multiple PWSs

simultaneously?

– Reason for considering change:

– Facilitates compliance tracking by the Regions and States

Potential Change Between 

UCMR 3 and UCMR 4: SDWARS

June 25, 2014 U.S. Environmental Protection Agency 68

Revisions to the Unregulated 

Contaminant Monitoring Rule

(UCMR 4) for Public Water Systems

Discussion

11:30 a.m. – 11:45 a.m.

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 34
June 25, 2014 U.S. Environmental Protection Agency 69

Revisions to the Unregulated 

Contaminant Monitoring Rule 

(UCMR 4) for Public Water Systems

Public Stakeholder Meeting 

and Webinar

Lunch Break

Meeting will resume at 1:15 p.m.

UCMR 4 Candidate Selection, 

Rationale and Method 

Considerations

Public Meeting and Webinar

Washington D.C.

June 25th, 2014 – 1:15 p.m.

Melissa Simic and Steve Wendelken

United States Environmental Protection Agency

Office of Ground Water and Drinking Water

Technical Support Center

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 35
Overview

• UCMR 4 Schedule

• Candidate Selection Process and Rationale

• Method Considerations

• Health and Occurrence Data with Sources

• Contaminant Specific Information by Method

• Other UCMR 4 Contaminants Under 

Consideration

UCMR 4 Development and Review 

UCMR 4 Stakeholder 

Meeting 

June 25, 2014 

Publish 

UCMR 4 

Proposal

UCMR 4 monitoring 

tentatively starting 

in 2018

y 72

C

Per

2015

y Jun Jul Aug Sep

Public 

omment 

iod Ends 

Publish 

Final Rule 

December 2016 

Draft Final Rule 

UCMR 4 

Implementation

2016 2017

 Oct Nov Dec

2014

Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Ma

2013

UCMR Method 

Development 

Stakeholder Meeting 

May 15, 2013 

Public 

Comment 

Period Begins

June 25, 2014 U.S. Environmental Protection Agenc

UCMR 4 Schedule

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 36
UCMR 4 Prioritization Process

45 CCL + 48 related non-CCL analytes

[16 methods] 

UCMR 4 Candidates:

31 CCL + 18 related non-CCL 

analytes [9 methods] 

+ other contaminants under 

consideration2

Propose up to 30 

contaminants for 

comment

• Not currently regulated or previous regulatory 

determination

• Not monitored for on UCMR 2 or UCMR 3

• Low national occurrence is not anticipated

• Have a completed drinking water method

Most contaminants in method group:

• Have an available health assessment to facilitate 

regulatory determinations and/or high public concern 

• Have critical health endpoints, probable carcinogens, 

active pesticides

• Have an occurrence data gap

• Workgroup and stakeholder input

• Cost-effective method group

• Implementation considerations

 After considering comments, publish up to 

30 contaminants for UCMR 4 monitoring 

tentatively starting in 2018

June 25, 2014 U.S. Environmental Protection Agency 73

1 59 unique CCL 4 nominations; 11 removed because already on CCL 3 or regulated

2 Nitrate/Nitrite, 4 unregulated brominated DBPs

CCL 3 [106 chemicals + 12 microbes] 

+ 48 CCL 4 nominations1 = 166 contaminants

CCL and Related Candidates for UCMR 4 

June 25, 2014 U.S. Environmental Protection Agency 74

Method 200.8 + 2 Analytes

Germanium

Manganese (CCL 4 nomination) 

Nickel

Thorium

Method 525.3

Disulfoton Profenofos

Ethoprop Oxyfluorfen 

alpha-Hexachlorocyclohexane Vinclozolin 

Permethrin, trans- Dimethipin (Method 530)

Permethrin, cis- Tebuconazole

Tribufos 

Method 530 – In Development

Quinoline 

o-Toluidine 

Butylated hydroxyanisole 

Dimethipin (Method 525.3)

Method 538

Dicrotophos 

Oxydemeton-methyl 

Methamidophos 

Acephate 

Method 541 – In Development

1-Butanol 

2-Propen-1-ol 

2-Methoxyethanol 

Method 542 + 10 Analytes – In Development

Erythromycin Diclofenac

Triclosan (CCL 4 nomination) Naproxen

Carbamazepine Gemfibrozil

Diazepam Fluoxetine

Sulfamethoxazole Enalapril

Trimethoprim Phenytoin

Method 545 – In Development

Anatoxin-a 

Cylindrospermopsin 

Method 556.1 

Formaldehyde 

Acetaldehyde 

Method 544 + 6 Analytes – In Development

Microcystin-LR Microcystin-LF

Microcystin-YR Microcystin-LY

Microcystin-RR Nodularin

Microcystin-LA

Assessment Monitoring (List 1)

Screening Survey (List 2)

Potential methods being investigated

Legionella pneumophila 

The candidates highlighted in gray are related non-CCL 3 analytes

Under Evaluation

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 37
Potential EPA Methods

June 25, 2014 U.S. Environmental Protection Agency 75

Assessment Monitoring (List 1) Screening Survey (List 2)

Method 200.8 (ICP-MS) Method 544 (LC/MS/MS)

Method 525.3 (GC/MS) Method 545 (LC/ESI-MS/MS)

Method 530 (GC/MS)

Method 538 (DAI-LC/MS/MS)

Method 541 (GC/MS)

Method 542 (LC/MS/MS)

Method 556.1 (Fast GC)

• Inductively Coupled Plasma (ICP)

• Gas Chromatography (GC)

• Direct Aqueous Injection (DAI)

• Mass Spectrometry (MS)

• Liquid Chromatography (LC)

• Electrospray Ionization (ESI) 

• The monitoring location(s) are still being determined

Health Effects Data

• Identify health effects information compiled during CCL 3 + CCL 4 nominations

– Potential health effects

– Reference Dose (RfD) or other non-cancer health value

– Cancer Slope Factor (CSF)

– Health Reference Levels (HRLs)* 

– Cancellation Status for Pesticides

• Determine health assessment status:

– (1) Available health assessment from an EPA (i.e., IRIS, OPP, OW) or comparable non-EPA source 

(e.g., ATSDR)

– (2) Available health assessment from an EPA or comparable non-EPA source needs to be updated

– (3) A health assessment is not currently available but sufficient information may exist to conduct a 

health assessment

– (4) A health assessment is not currently available and there are substantial data needs

June 25, 2014 U.S. Environmental Protection Agency 76

*Note: HRLs are risk-derived concentrations against which to evaluate the occurrence data to determine if contaminants 

occur at levels of potential public health concern. HRLs are not final determinations about the level of a contaminant in 

drinking water that must not be exceeded to protect any particular population. 

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 38
Health Effects Data Sources

• EPA

– Office of Pesticide Programs (OPP)

– Integrated Risk Information System (IRIS)

– Office of Water Health Advisory (HA)

• Agency for Toxic Substances and Disease Registry (ATSDR)

• California Office of Environmental Health and Hazard Assessment (OEHHA)

• Risk Assessment Information System (RAIS) 

• Registry of Toxic Effects of Chemical Substances (RTECS)

• Joint FAO/WHO Expert Committee on Food Additives (JECFA) 

– Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization 

(WHO)

• Center for Disease Control (CDC)

• Single Studies

June 25, 2014 U.S. Environmental Protection Agency 77

Note: The health values are derived using the health effects information available during CCL 3. The health values 

are subject to change as health assessments are completed or updated based on more recent health effects 

information.

Calculating CCL 3 Health Reference Levels

Non-Cancer CCL3 HRL (mg/L) = [(RfD x BW)/DWI] x RSC] 

Where:

• RfD = Reference Dose (mg/kg-day)

RfD = Point of Departure (POD) ÷Uncertainty Factors (UF) 

Point of Departure = the dose (e.g., No Observed Adverse Effect Level (NOAEL) or Lowest 

Observed Adverse Effect level (LOAEL))

• BW = Body Weight for an adult, assumed to be 70 kilograms (kg) 

• DWI = Drinking Water Intake for an adult, assumed to be 2 L/day (90th

percentile)

• RSC = 20% Relative Source Contribution, assumed to be the level of exposure 

from drinking water when compared to other sources.

June 25, 2014 U.S. Environmental Protection Agency 78

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 39
Calculating CCL 3 Health Reference Levels

Cancer Unit Risk (μg/L)-1 = CSF x [(DWI x CW)/BW]

Where:

• CSF = Cancer Slope Factor (mg/kg/day)-1

• DWI = Drinking Water Intake for an adult, assumed to be 2 L/day (90th 

percentile)

• CW = Unit risk concentration in drinking water of 0.001 mg/L (1 μg/L)

• BW = Body Weight for an adult, assumed to be 70 kilograms (kg) 

The cancer HRL is the concentration of a contaminant in drinking water 

corresponding to an excess estimated lifetime cancer risk of one-in-a-million (1x 

10-6), calculated as follows:

Cancer HRL (μg/L) = Risk Level of 10-6 ÷ Unit Risk (μg/L)-1 

June 25, 2014 U.S. Environmental Protection Agency 79

Occurrence Data and Information Sources

Finished Water Data

• Unregulated Contaminant Monitoring Rule (UCMR)

– UCMR 1 Screening Survey/Assessment Monitoring (2001 – 2003)

• National Inorganics and Radionuclides Survey (NIRS) (1984 – 1986)

• Disinfection By-Product Information Collection Rule (DBP-ICR) Data (1997 

– 1998)

• U.S. Department of Agriculture Pesticide Data Program (PDP)

• Pesticides Pilot Monitoring Program (PPMP)

• California Department of Health Services (CAL DHS) 

• Small-Scale Local Occurrence Studies

 

June 25, 2014 U.S. Environmental Protection Agency 80

Note: Occurrence results are presented as a number or percent of detects at systems/sites. Where available, a 

statement is included about the maximum concentration being above or below the health reference level (HRL).

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 40
Occurrence Data and Information 

Sources (cont.)

Supplemental Drinking Water and Ambient Water Data

• United States Geological Survey (USGS), Ambient Water

– National Water Quality Assessment Program (NAWQA) 

– National Reconnaissance of Emerging Contaminants (NREC)

– National Random and Focused Source Water Surveys (with AWWARF)

– Special reports

• Other specialized studies and literature 

Production, Release, Usage and Other Data

• Toxic Release Inventory (TRI)

• National Center for Food and Agricultural Policy (NCFAP)

• OPP Reregistration Eligibility Document (RED) 

– Data from pesticide registrants

• Chemical Update System/Inventory Update Reporting Program (CUS/IUR)

• Cancellation Status for Pesticides

• Persistent, Bioaccumulative and Toxic (PBT) Profiler

June 25, 2014 U.S. Environmental Protection Agency 81

Metals

June 25, 2014 U.S. Environmental Protection Agency 82

EPA Method 200.8 (ICP/MS), 1994

Determination of trace elements in waters by inductively coupled plasma - mass 

spectrometry, revision 5.4

Analytes 

• Manganese (2)

• Nickel

• Germanium (4)

• Thorium

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 41
Manganese: Background

• Heavy metal element found in over 100 naturally occurring 

minerals, including silicates, carbonates, sulfides, oxides, 

phosphates and borates; ubiquitous in soil, water, food and air 

• Small amounts found in foods are an essential nutrient for humans 

and animals 

• Commercially imported manganese compounds include 

ferromanganese (used in the production of steel), manganese 

sulfate (fertilizer), manganese dioxide (matches, batteries, 

fireworks) and potassium permanganate (wastewater and drinking 

water treatment chemical)

• Common manganese compounds range from insoluble to 

moderately soluble in water

June 25, 2014 U.S. Environmental Protection Agency 83

Manganese: Health Effects

• Health Assessment Status = 2

– 1995 IRIS Risk Assessment 

• RfD = 0.047 mg/kg-day

– Critical Effect = Central nervous system effects

– NOAEL = 0.14 mg/kg-day; UF = 3 [Reflects a modifying factor of 3 to adjust 

for increased bioavailability when in drinking water]

• HRL: 300 μg/L (non-cancer)

• Sensitive populations: Children, the elderly, pregnant 

women, iron deficient individuals, and individuals with 

impaired liver function

– Recent studies indicate concern for neurological effects in children 

and infants

June 25, 2014 U.S. Environmental Protection Agency 84

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 42
Manganese: Occurrence

• National Inorganics and Radionuclides Survey (NIRS), Finished Water, 

1984-1986 (MRL = 1 μg/L):

– 672 detections (median = 11.96 μg/L) out of 989 sites; Maximum detect (1,341 μg/L) 

> HRL (300 μg/L)

• USGS, National Water-Quality Assessment Program (NAWQA), Ambient 

Water, 1992-2001: 

– 6,447 detections (median = 19 μg/L) out of 8,002 sites; Maximum detect (70,000 

μg/L) > HRL (300 μg/L)

• USGS, Toccalino et al., 2010, Ambient Water: 

– 543 detections (median = 8.99 μg/L) out of 808 samples; Maximum detect (1,923 

μg/L) > HRL (300 μg/L)

• Toxic Release Inventory – Total:

– 15,872,968 lbs/yr in 48 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 85

Germanium: Background

• Naturally-occurring element in earth’s crust and oceans, 

widely distributed in low concentrations in oxide and 

sulfide minerals; commercially available in combination 

with other elements and produced mainly as a 

byproduct of zinc ore processing

• Used primarily in infrared optics, fiber-optic systems, 

electronics and solar electric applications 

• Some germanium compounds (e.g., germanium 

dioxide) are water soluble

June 25, 2014 U.S. Environmental Protection Agency 86

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 43
Germanium: Health Effects

• Health Assessment Status = 4

– Registry of Toxic Effects of Chemical Substances (RTECS): Single Study 

(Obara et al. 1991)

• RfD-like = 0.0001 mg/kg-day

– Critical Effect = Kidney, Ureter, Bladder - changes in tubules (including acute 

renal failure, acute tubular necrosis)

– LOAEL = 0.318 mg/kg-day*; Default UF = 3,000

• CCL 3 HRL: 0.744 μg/L (non-cancer)

• Sensitive populations: Individuals with compromised renal 

function 

*OW did not obtain the same LOAEL as RTECS using the data in the identified paper. Based on OW’s evaluation of the dose 

information in the report, the LOAEL should be about ten times larger (i.e., 3.18 mg/kg-day).

June 25, 2014 U.S. Environmental Protection Agency 87

Germanium: Occurrence

• National Inorganics and Radionuclides Survey (NIRS), 

Finished Water, 1984-1986 (MRL = 22 μg/L):

– 4 detections (median = 220 μg/L) out of 989 PWSs; Minimum 

detection (26 μg/L) > HRL (0.744 μg/L)

• Chemical Update System / Inventory Update Reporting: 

– <500K lbs/yr in 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 88

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 44
Semivolatile Organic Chemicals

June 25, 2014 U.S. Environmental Protection Agency 89

EPA Method 525.3 (GC/MS), 2012

Determination of semivolatile organic chemicals in drinking water by solid 

phase extraction and capillary column gas chromatography/mass spectrometry, 

version 1.0

Analytes

• Disulfoton (1) • Tribufos (1)

• Ethoprop (1) • Profenofos (1)

• Alpha-Hexachlorocyclohexane (2) • Oxyfluorfen (2)

• Permethrin, trans - (1) • Vinclozolin (2)

• Permethrin, cis- (1) • Dimethipin (method 530) (1)

• Tebuconazole (1)

Disulfoton: Background

• Organophosphate pesticide; used as an insecticide; currently 

registered for use on over 35 crops, plus domestic outdoor 

use on potted plants and ornamentals 

• Production cancelled 2009 (74 FR 48551)

• Expected to be not very mobile to moderately mobile in 

water, based on physical and chemical properties

• Projected half-life in water is 7 - 41 days (PBT Profiler)

• The PBT Profiler (2009) predicts that 17% of disulfoton will 

partition to water when modeled in a four-compartment 

system (water, air, soil and sediment)

• Moderately persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 90

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 45
Disulfoton: Health Effects

• Health Assessment Status = 1

– 2006 OPP Risk Assessment 

• RfD = 0.00013 mg/kg-day 

– Critical Effect = Plasma, RBC, brain and corneal cholinesterase 

(ChE) inhibition 

– NOAEL = 0.013 mg/kg-day; UF = 100

• CCL3 HRL: 0.91 μg/L (non-cancer) 

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 91

Disulfoton: Occurrence

• UCMR 1 Screening Survey, Finished Water, 2001-2003 (MRL = 0.5 

μg/L):

– No detections of 2k samples in 295 systems

• USDA, Pesticide Data Program (PDP), Finished Water, 2001-2009 (min 

detect = N/A): 

– No detections in 4k samples

• USGS, Toccalino et al. 2010, Ambient Water (MRL = 0.01 - 0.02 μg/L)

– No detections in 647 samples/systems

• National Center for Food and Agricultural Policy (NCFAP) Pesticide 

Application:

– 1,196,066 lbs/yr in 33 states in 1997

June 25, 2014 U.S. Environmental Protection Agency 92

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 46
Ethoprop: Background

• A phosphorodithioate pesticide; used as an insecticide

• Expected to be moderately mobile in water, based on 

physical and chemical properties

• PBT Profiler (2009) predicts 23% of ethoprop will partition 

to water when modeled in a four-compartment system 

(water, air, soil and sediment)

June 25, 2014 U.S. Environmental Protection Agency 93

Ethoprop: Health Effects

• Health Assessment Status = 1

– 2001 OPP Risk Assessment 

• RfD = 0.0001 mg/kg-day*

– Critical Effect = Plasma cholinesterase (ChE) inhibition

– NOAEL = 0.01 mg/kg-day; UF = 100

• CCL 3 HRL: 0.7 μg/L (non-cancer) 

• Sensitive populations: None identified

*Note: 2006 OPP Risk Assessment; RfD = 0.0014 Brain ChE inhibition; Likely carcinogen, CSF = 0.0281 mg/kg-day-1

June 25, 2014 U.S. Environmental Protection Agency 94

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 47
Ethoprop: Occurrence

• USGS, National Water-Quality Assessment Program (NAWQA), Ambient 

Water, 1992-2001:

– 84 detections (median = 0.011 μg/L) out of 7,118 sites; Maximum detection (1.95 μg/L) 

> HRL (0.7 μg/L)

• Pesticide Pilot Monitoring Program (PPMP), Finished Water, 1999:

– 0 detections out of 228 samples

• National Center for Food and Agricultural Policy (NCFAP) Pesticide 

Application:

– 1,010,807 lbs/yr in 28 states in 1997

• EPA OPP estimate of pesticide usage:

– 691,000 lbs/yr (2006 estimate)

• Toxic Release Inventory – Total:

– 77,786 lbs/yr in 4 states in 2004; 35,660 lbs/yr in 2 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 95

alpha-Hexachlorocyclohexane: Background

• A cyclic halogenated alkane; component of lindane, 

formerly used as an insecticide

• Expected to be not very to moderately mobile in water, 

based on physical and chemical properties

• The PBT Profiler (2009) predicts that 6% of alphahexachlorocyclohexane will partition to water when 

modeled in a four-compartment system (water, air, soil 

and sediment)

June 25, 2014 U.S. Environmental Protection Agency 96

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 48
alpha-Hexachlorocyclohexane: Health Effects

• Health Assessment Status = 2

– 1987 IRIS Risk Assessment 

• Slope Factor = 6.3 (mg/kg-day)-1

• Cancer Class = B2 

– Sufficient evidence of carcinogenicity in animals

• CCL 3 HRL: 0.006 μg/L (cancer) 

• Sensitive populations: Children may be more 

sensitive, but no definitive studies

June 25, 2014 U.S. Environmental Protection Agency 97

alpha-Hexachlorocyclohexane: Occurrence

• USGS, National Water Quality Assessment Program (NAWQA), Ambient 

Water, 1992-2001 (MRL = 0.002 μg/L):

– 21 detections (median = 0.011 μg/L) out of 7,119 sites; Maximum detection (0.21 

μg/L) > HRL (0.006 μg/L)

• National Center for Food and Agricultural Policy (NCFAP) Pesticide 

Application:

– No data in 1997

• Chemical Update System / Inventory Update Reporting: 

– No Reports in 2002

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 98

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 49
Permethrin, cis- and trans-: Background

• Permethrin is a substituted diphenyl ether; used as an 

insecticide 

• Expected to be not very to moderately mobile in water, 

based on physical and chemical properties

• The PBT Profiler (2009) predicts that 2% of permethrin 

will partition to water when modeled in a fourcompartment system (water, air, soil and sediment)

• May or may not be persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 99

Permethrin, cis- and trans-: Health Effects

• Health Assessment Status = 1

– 2009 OPP Risk Assessment 

• Slope Factor = 0.0096 (mg/kg-day)-1

• Cancer Class = L

– Likely to be carcinogenic to humans 

• CCL 3 HRL: 3.65 μg/L (cancer) 

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 100

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 50
Permethrin, cis- and trans-: Occurrence

• National Center for Food and Agricultural Policy (NCFAP) 

Pesticide Application:

– 1,066,056 lbs/yr in 48 states in 1997

• EPA OPP estimate of pesticide usage:

– 2 million lbs/yr (2007 estimate)

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– 17,979 lbs/yr in 7 states in 2004; 2,116 lbs/yr in 5 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 101

Tribufos: Background

• Alkylated phosphorotrithioate pesticide; used as an 

insecticide and cotton defoliant 

• Mobility in water uncertain, physical and chemical 

properties provide conflicting indications

• The PBT Profiler (2009) predicts that 14% of tribufos will 

partition to water when modeled in a four-compartment 

system (water, air, soil and sediment)

• Not persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 102

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 51
Tribufos: Health Effects

• Health Assessment Status = 1

– 2006 OPP Risk Assessment 

• RfD = 0.001 mg/kg-day 

– Critical Effect = Plasma cholinesterase (ChE) inhibition 

– NOAEL = 0.1 mg/kg-day; UF = 100

• CCL 3 HRL: 7 μg/L (non-cancer) 

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 103

Tribufos: Occurrence

• Pesticide Pilot Monitoring Program (PPMP), Finished Water, 1999:

– 0 detections out of 221 samples

• National Center for Food and Agricultural Policy (NCFAP) Pesticide 

Application:

– 4,918,265 lbs/yr in 16 states in 1997

• EPA OPP estimate of pesticide usage:

– 4.5 million lbs/yr (2006 estimate)

• Chemical Update System / Inventory Update Reporting: 

– 10K – 500K lbs/yr in 2002; <500K lbs/yr in 2006

• Toxic Release Inventory – Total:

– 7 lbs/yr in 1 state in 2004; 9 lbs/yr in 2 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 104

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 52
Profenofos: Background

• A phosphorothioate pesticide, applied as an insecticide

• Mobility in water uncertain, physical and chemical 

properties provide conflicting indications

• The PBT Profiler (2009) predicts that 9% of profenofos 

will partition to water when modeled in a fourcompartment system (water, air, soil and sediment)

• Persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 105

Profenofos: Health Effects

• Health Assessment Status = 1

– 2006 OPP Risk Assessment 

• RfD = 0.00005 mg/kg-day

– Critical Effect = Plasma and RBC cholinesterase (ChE) 

inhibition

– NOAEL = 0.005 mg/kg-day; UF = 100

• CCL 3 HRL: 0.35 μg/L (non-cancer) 

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 106

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 53
Profenofos: Occurrence

• Pesticide Program Monitoring Program (PPMP), Finished Water, 

1999:

– 0 detections out of 221 samples

• National Center for Food and Agricultural Policy (NCFAP) Pesticide 

Application:

– 879,776 lbs/yr in 14 states in 1997

• EPA OPP estimate of pesticide usage:

– 775,000 lbs/yr (2006 estimate)

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– 255 lbs/yr in 1 state in 2004; no data 2010

June 25, 2014 U.S. Environmental Protection Agency 107

Oxyfluorfen: Background

• A substituted diphenyl ether; used as a herbicide

• Expected to be not very to moderately mobile in water, 

based on physical and chemical properties

• The PBT Profiler (2009) predicts that 5% of oxyfluorfen 

will partition to water when modeled in a fourcompartment system (water, air, soil and sediment)

• Persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 108

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 54
Oxyfluorfen: Health Effects

• Health Assessment Status = 2

– 1986 IRIS Risk Assessment

• RfD = 0.003 mg/kg-day

– Critical Effect = Liver toxicity (e.g., increased liver weight and 

lesions)

– NOAEL = 0.3 mg/kg-day; UF = 100

• CCL 3 HRL: 21 μg/L (non-cancer) 

• Sensitive populations: Individuals with preexisting liver conditions

*Note: 2002 OPP Risk Assessment; RfD = 0.03 mg/kg-day based on liver toxicity 

June 25, 2014 U.S. Environmental Protection Agency 109

Oxyfluorfen: Occurrence

• Pesticide Pilot Monitoring Program (PPMP), Finished Water, 1999:

– 0 detections out of 221 samples

• National Center for Food and Agricultural Policy (NCFAP) Pesticide 

Application:

– 705,255 lbs/yr in 37 states in 1997

• EPA OPP estimate of pesticide usage:

– 761,000 lbs/yr on average between 1990 and 1999; usage increasing

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– 5 lbs/yr in 2 states in 2004; 2,503 lbs/yr in 1 state in 2010

June 25, 2014 U.S. Environmental Protection Agency 110 

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 55
Vinclozolin: Background

• An oxazolidine pesticide; used as a fungicide

• Expected to be moderately to very mobile in water, based 

on physical and chemical properties

• The PBT Profiler (2009) predicts that 12% of vinclozolin 

will partition to water when modeled in a fourcompartment system (water, air, soil and sediment)

• Persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 111

Vinclozolin: Health Effects

• Health Assessment Status = 2

– 2000 OPP Risk Assessment 

• RfD = 0.012 mg/kg-day

– Critical Effect = Lesions in the lungs, liver, ovaries and eye

– NOAEL = 1.2 mg/kg-day; UF = 100

• CCL 3 HRL: 84 μg/L (non-cancer)

• Sensitive populations: Fetuses, neonates, and 

adolescents during puberty could be a sensitive 

population

June 25, 2014 U.S. Environmental Protection Agency 112 

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 56
Vinclozolin: Occurrence

• National Center for Food and Agricultural Policy (NCFAP) 

Pesticide Application:

– 121,959 lbs/yr in 26 states in 1997

• EPA OPP estimate of pesticide usage:

– 141,000 lbs/yr in 2000; expected to drop to 71,000 lbs/yr after the phaseout of several uses was completed in 2004

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 113 

Dimethipin: Background

• A cyclic dithiane pesticide; used as an herbicide and 

plant growth regulator

• Expected to be very mobile in water, based on physical 

and chemical properties

• The PBT Profiler (2009) predicts that 46% of dimethipin 

will partition to water when modeled in a fourcompartment system (water, air, soil and sediment)

• Moderately persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 114 

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 57
Dimethipin: Health Effects

• Health Assessment Status = 1

– 2005 OPP Risk Assessment 

• RfD = 0.0218 mg/kg-day

– Critical Effect = Kidney, lungs, duodenum, liver, glandular 

stomach, heart, aortic artery and testes toxicity. Decreased 

body weight gain 

– NOAEL = 2.18 mg/kg-day; UF = 100

• CCL 3 HRL: 153 μg/L (non-cancer)

• Sensitive populations: Non identified

June 25, 2014 U.S. Environmental Protection Agency 115 

Dimethipin: Occurrence

• National Center for Food and Agricultural Policy (NCFAP) 

Pesticide Application:

– 282,458 lbs/yr in 14 states in 1997

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– 250 lbs/yr in 1 state in 2004; 87 lbs/yr in 1 state in 2010

June 25, 2014 U.S. Environmental Protection Agency 116 

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 58
Tebuconazole: Background

• A substituted triazole pesticide; used as a fungicide

• Expected to be moderately to very mobile in water, based 

on physical and chemical properties

• The PBT Profiler (2009) predicts that 9% of tebuconazole 

will partition to water when modeled in a fourcompartment system (water, air, soil and sediment)

• Persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 117 

Tebuconazole: Health Effects

• Health Assessment Status = 1

– 2008 OPP Risk Assessment 

• RfD = 0.03 mg/kg-day

– Critical Effect = Decreased body weights, absolute brain 

weights, brain measurements and motor activity in offspring

– LOAEL = 8.8 mg/kg-day; UF = 300

• CCL 3 HRL: 210 μg/L (non-cancer)

• Sensitive populations: Infants and children

June 25, 2014 U.S. Environmental Protection Agency 118 

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 59
Tebuconazole: Occurrence

• National Center for Food and Agricultural Policy (NCFAP) 

Pesticide Application:

– 478,568 lbs/yr in 16 states in 1997

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 119 

Semivolatile Organic Chemicals

June 25, 2014 U.S. Environmental Protection Agency 120

Draft EPA Method 530 (GC/MS) 

Anticipated Publication Year 2014

Determination of select semivolatile organic chemicals in drinking water by solid 

phase extraction and capillary column gas chromatography/mass spectrometry

Analytes

• Quinoline (1) • Butylated hydroxyanisole (3)

• o-Toluidine (4) • Dimethipin (1) (method 525.3)

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 60
Quinoline: Background

• Fused aromatic amine; used as a pharmaceutical (antimalarial) and flavoring agent, also produced as a 

chemical intermediate

• Mobility in water uncertain, physical and chemical 

properties provide conflicting indications

• PBT Profiler (2009) predicts 31% of quinoline will 

partition to water when modeled in a four-compartment 

system (water, air, soil and sediment)

• Not persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 121

Quinoline: Health Effects

• Health Assessment Status = 1

– 2001 IRIS Risk Assessment 

• Slope Factor = 3 (mg/kg-day)-1

• Cancer Class = B2 

– Sufficient evidence of carcinogenicity in animals

• CCL 3 HRL: 0.01 μg/L (cancer) 

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 122

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 61
Quinoline: Occurrence

• Chemical Update System / Inventory Update Reporting: 

– 10K – 500K lbs/yr in 2002; 1M – <10M lbs/yr in 2006

• Toxic Release Inventory – Total:

– 28,629 lbs/yr in 8 states in 2004; 15,789 lbs/yr in 9 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 123

o-Toluidine: Background

• Aminated aromatic compound; used in production of 

dyes, rubber, pharmaceuticals and pesticides

• Expected to be moderately to very mobile in water 

based on physical and chemical properties

• PBT Profiler (2009) predicts 41% of o-toluidine will 

partition to water when modeled in a four-compartment 

system (water, air, soil and sediment)

• Not persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 124

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 62
o-Toluidine: Health Effects

• Health Assessment Status = 4

– California Office of Environmental Health and Hazard Assessment 

(OEHHA), 2008: Study not provided

• Slope Factor = 0.18 (mg/kg-day)-1

• IARC Cancer Group = 2A

– Probably carcinogenic to humans

• CCL 3 HRL: 0.194 μg/L (cancer) 

• Sensitive populations: Infants and children

June 25, 2014 U.S. Environmental Protection Agency 125

o-Toluidine: Occurrence

• Chemical Update System / Inventory Update Reporting: 

– >10M – 50M lbs/yr in 2002; 10M – <50M lbs/yr in 2006

• Toxic Release Inventory – Total:

– 10,774 lbs/yr in 9 states in 2004; 6,623 lbs/yr in 1 state in 2010

June 25, 2014 U.S. Environmental Protection Agency 126

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 63
Butylated hydroxyanisole: Background

• Alkylated methoxyphenol; used as an antioxidant in foods, 

particularly those with high fat content and packaged foods

• Expected to be moderately mobile to not very mobile in 

water, based on physical and chemical properties

• PBT Profiler (2009) predicts 15% of butylated 

hydroxyanisole will partition to water when modeled in a 

four-compartment system (water, air, soil and sediment)

• Projected half-life in water is 38 days (PBT Profiler)

• Moderately persistent in the water 

June 25, 2014 U.S. Environmental Protection Agency 127

Butylated hydroxyanisole: Health Effects

• Health Assessment Status = 3

– Registry of Toxic Effects of Chemical Substances (RTECS), 

2006: Single Study (Adelaide, S.A., Australia 1959)

• RfD-like = 0.000083 mg/kg-day

– Critical Effect = Changes in liver weight

– LOAEL = 0.249 mg/kg-day; Default UF = 3,000

• CCL 3 HRL: 0.581 μg/L (non-cancer)

• Sensitive populations: Fetus and neonate may 

be sensitive to neurodevelopmental effects 

from exposure to high levels

June 25, 2014 U.S. Environmental Protection Agency 128

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 64
Butylated hydroxyanisole: Occurrence

• USGS, National Reconnaissance of Emerging Contaminants (NREC), 

Ambient Surface Water, 1999-2004: 

– 2 detections (median = 0.1 μg/L) in 85 sites; Median of detections < HRL (0.581 

μg/L)

• USGS, Koplin, et al., 2002, Ambient Water: 

– 2.4% detection rate (median = 0.1 μg/L) out of 85 sites; Maximum detect (0.2 μg/L) 

< HRL

• USGS, Focazio, et al., 2008, Ambient Water: 

– No detects out of 73 sites

• Chemical Update System / Inventory Update Reporting: 

– 10K – 500K lbs/yr in 2002; <500K lbs/yr in 2006

• Toxic Release Inventory – Total:

– No data in 2004; No data in 2010

June 25, 2014 U.S. Environmental Protection Agency 129

Presenter

Steve Wendelken, USEPA

June 25, 2014 U.S. Environmental Protection Agency 130

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 65
Organic Contaminants

June 25, 2014 U.S. Environmental Protection Agency 131

EPA Method 538 (DAI-LC/MS/MS), 2009

Determination of selected organic contaminants in drinking water by direct 

aqueous injection-liquid chromatography/tandem mass spectrometry, 

version 1.0

Analytes

• Dicrotophos (1) • Methamidiphos (1)

• Oxydemeton-methyl (1) • Acephate (1)

Dicrotophos: Background

• Organophosphate pesticide; used as an insecticide on 

cotton

• Expected to be moderately mobile to very mobile in 

water, based on chemical and physical properties

• The PBT Profiler (2009) predicts that 39% of 

dicrotophos will partition to water when modeled in a 

four-compartment system (water, air, soil and sediment)

• Moderately persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 132

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 66
Dicrotophos: Health Effects

• Health Assessment Status = 1

– 2006 OPP Risk Assessment 

• RfD = 0.00007 mg/kg-day

– Critical Effect = Plasma, RBC and brain cholinesterase (ChE) 

inhibition

– LOAEL = 0.02 mg/kg-day; UF = 300

• CCL 3 HRL: 0.49 μg/L (non-cancer)

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 133

Dicrotophos: Occurrence

• Pesticide Pilot Monitoring Program (PPMP), Finished Water, 1999: 

– 0 detections

• National Center for Food and Agricultural Policy (NCFAP) Pesticide 

Application:

– 359,726 lbs/yr in 13 states in 1997

• OPP Pesticide Usage Estimate

– 500,000 lbs/yr (2006 estimate)

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 134

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 67
Oxydemeton-methyl: Background

• Thiophosphate pesticide, used as an insecticide on 

broccoli, lettuce and other crops

• Expected to be very mobile in water based on chemical 

and physical properties

• The PBT Profiler (2009) predicts that 39% of 

oxydemeton-methyl will partition to water when 

modeled in a four-compartment system (water, air, soil 

and sediment)

• Moderately persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 135

Oxydemeton-methyl: Health Effects

• Health Assessment Status = 1

– 2006 OPP Risk Assessment 

• RfD = 0.00013 mg/kg-day

– Critical Effect = RBC and brain cholinesterase (ChE) inhibition

– NOAEL = 0.013 mg/kg-day; UF = 100

• CCL 3 HRL: 0.91 μg/L (non-cancer)

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 136

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 68
Oxydemeton-methyl: Occurrence

• Pesticide Pilot Monitoring Program (PPMP) Finished Water, 1999: 

– 0 detections

• National Center for Food and Agricultural Policy (NCFAP) Pesticide 

Application:

– 154,227 lbs/yr in 19 states in 1997

• OPP Pesticide Usage Estimate

– 145,000 – 186,000 lbs/yr (2006 estimate)

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 137

Methamidophos: Background

• Phosphoramidothioate pesticide used as an insecticide on 

potatoes and other crops; also a degradation product of 

acephate, an organic phosphoramide insecticide

• Expected to be very mobile in water, based on chemical and 

physical properties

• The PBT Profiler (2009) predicts that 39% of 

methamidophos will partition to water when modeled in a 

four-compartment system (water, air, soil and sediment)

• Moderately persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 138

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 69
Methamidophos: Health Effects

• Health Assessment Status = 1

– 2006 OPP Risk Assessment 

• RfD = 0.0003 mg/kg-day

– Critical Effect = Brain cholinesterase (ChE) inhibition

– NOAEL = 0.03 mg/kg-day; UF = 100

• CCL 3 HRL: 2.1 μg/L (non-cancer)

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 139

Methamidophos: Occurrence

• National Center for Food and Agricultural Policy (NCFAP) 

Pesticide Application:

– 965,584 lbs/yr in 39 states in 1997

• OPP Pesticide Usage Estimate

– 640,000 lbs/yr (2006 estimate)

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 140

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 70
Acephate: Background

• Organic phosphoramide pesticide; used as an 

insecticide on cotton, tobacco and other crops

• Expected to be very mobile in water, based on chemical 

and physical properties

• Projected half-life in water of 38 days (PBT Profiler)

• PBT Profiler (2009) predicts 46% of acephate will 

partition to water when modeled in a four-compartment 

system (water, air, soil and sediment)

• Not persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 141

Acephate: Health Effects

• Health Assessment Status = 1

– 2006 OPP Risk Assessment 

• RfD = 0.0012 mg/kg-day

– Critical Effect = Brain cholinesterase (ChE) inhibition

– NOAEL = 0.12 mg/kg-day; UF = 100

• CCL 3 HRL: 8.4 μg/L (non-cancer)

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 142

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 71
Acephate: Occurrence

• National Center for Food and Agricultural Policy (NCFAP) 

Pesticide Application:

– 2,462,354 lbs/yr in 35 states in 1997

• EPA OPP estimate of pesticide usage:

– 4-5 million lbs/yr (2006 estimate)

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– 20,751 lbs/yr in 5 states in 2004; 5,816 lbs/yr in 2 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 143

Alcohols

June 25, 2014 U.S. Environmental Protection Agency 144

Draft EPA Method 541 (GC/MS)

Anticipated Publication Year 2014 

Analysis of low molecular weight alcohols in drinking water by gas 

chromatography mass spectrometry

Analytes

• 1-Butanol (2) • 2-Methoxyethanol (3)

• 2-Propen-1-ol (2)

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 72
1-Butanol: Background

• Alkyl alcohol compound; used as a paint solvent and 

food additive, also formed as a chemical intermediate

• Expected to be moderately mobile to very mobile in 

water, based on chemical and physical properties

• PBT Profiler (2009) predicts 40% of 1-butanol will 

partition to water when modeled in a four-compartment 

system (water, air, soil and sediment)

• Not persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 145

1-Butanol: Health Effects

• Health Assessment Status = 2

– 1987 IRIS Risk Assessment 

• RfD = 0.1 mg/kg-day

– Critical Effect = Abnormally diminished activity in the 

body/organs; inability to control muscles

– NOAEL = 125 mg/kg-day; UF = 1,000

• CCL 3 HRL: 700 μg/L (non-cancer)

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 146

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 73
1-Butanol: Occurrence

• Chemical Update System / Inventory Update Reporting: 

– >1B lbs/yr in 2002; ≥1B lbs/yr in 2006

• Toxic Release Inventory – Total:

– 17,648,846 lbs/yr in 44 states in 2004; 11,093,815 lbs/yr in 47 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 147

2-Propen-1-ol: Background

• Alkene/alcohol compound; chemical intermediate used 

in the manufacturing of flavorings and perfumes

• Expected to be moderately mobile to very mobile in 

water, based on chemical and physical properties

• PBT Profiler (2009) predicts 48% of 2-propen-1-ol will 

partition to water when modeled in a four-compartment 

system (water, air, soil and sediment)

• Not persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 148

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 74
2-Propen-1-ol: Health Effects

• Health Assessment Status = 2

– 1987 IRIS Risk Assessment 

• RfD = 0.005 mg/kg-day

– Critical Effect = Impaired renal function and increased relative 

liver, spleen and kidney weights

– NOAEL = 4.8 mg/kg-day; UF = 1,000

• CCL 3 HRL: 35 μg/L (non-cancer)

• Sensitive populations: Individuals with impaired 

pulmonary function may be particularly sensitive to the 

toxic effects of allyl alcohol through inhalation

June 25, 2014 U.S. Environmental Protection Agency 149

2-Propen-1-ol: Occurrence

• Chemical Update System / Inventory Update Reporting: 

– >100M – 500M lbs/yr in 2002; 100M – <500M lbs/yr in 2006

• Toxic Release Inventory – Total:

– 604,872 lbs/yr in 13 states in 2004; 445,833 lbs/yr in 13 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 150

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 75
2-Methoxyethanol: Background

• Monoalkylated alcohol; used in synthetic cosmetics, 

perfumes, fragrances, hair preparations, skin lotions 

and other consumer products

• Expected to be moderately mobile to very mobile in 

water, based on chemical and physical properties

• PBT Profiler (2009) predicts 45% of 2-methoxyethanol 

will partition to water when modeled in a fourcompartment system (water, air, soil and sediment)

• Not persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 151

2-Methoxyethanol: Health Effects

• Health Assessment Status = 3

– Risk Assessment Information System (RAISHE): Single Study 

(Gulati, et al. 1990)

• RfD-like = 0.003 mg/kg-day

– Critical Effect = Reproductive effects

– LOAEL = 9 mg/kg-day; Default UF = 3,000

• CCL 3 HRL: 21 μg/L (non-cancer)

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 152

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 76
2-Methoxyethanol: Occurrence

• Chemical Update System / Inventory Update Reporting: 

– >10M – 50M lbs/yr in 2002; 1M – <10M lbs/yr in 2006

• Toxic Release Inventory – Total:

– 153,774 lbs/yr in 16 states in 2004; 23,240 lbs/yr in 16 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 153

June 25, 2014 U.S. Environmental Protection Agency 154

Pharmaceuticals

Draft EPA Method 542 (LC/MS/MS)

Anticipated Publication Year 2014

Determination of pharmaceuticals and personal care products (PPCP) in 

drinking water by solid phase extraction (SPE) and liquid chromatography 

electrospray ionization tandem mass spectrometry 

Analytes

• Erythromycin (3)

• Carbamazepine

• Diazepam

• Sulfamethoxazole

• Trimethoprim

• Diclofenac

• Triclosan (1)

• Naproxen

• Gemfibrozil

• Fluoxetine

• Enalapril

• Phenytoin

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 77
Erythromycin: Background

• Used in pharmaceutical formulations as an antibiotic

• Expected to be moderately mobile to very mobile in 

water, based on chemical and physical properties

• Projected half-life in water of 180 days (PBT Profiler)

• The PBT Profiler (2009) predicts that 6% of 

erythromycin will partition to water when modeled in a 

four-compartment system (water, air, soil and sediment)

• Persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 155

Erythromycin: Health Effects

• Health Assessment Status = 3

– Joint FAO/WHO Expert Committee on Food Additives (JECFA), 

2006

• Acceptable Daily Intake (ADI) = 0.0007 mg/kg-day

– Critical Effect = Inhibition of beneficial gastrointestinal bacteria

• CCL 3 HRL: 4.9 μg/L (non-cancer)

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 156

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 78
Erythromycin: Occurrence

• USGS, National Reconnaissance of Emerging Contaminants (NREC), 

Ambient Surface Water, 1999-2004: 

– 22 detections (median = 0.1 μg/L) out of 104 sites; Maximum detect (1.7 μg/L) < 

HRL (4.9 μg/L)

• USGS, Focazio, et al., 2008, Ambient Water: 

– Maximum detect value = 0.3 μg/L; Maximum < HRL (4.9 μg/L) 

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 157

Triclosan: Background

• Antimicrobial agent found in many personal care products 

such as soaps, toothpaste; also used in many other 

products including clothing and plastics 

• Expected to be not very mobile to immobile in water, based 

on chemical and physical properties 

• Projected half-life in water of 60 days (PBT Profiler)

• The PBT Profiler (2009) predicts that 7% of triclosan will 

partition to water when modeled in a four-compartment 

system (water, air, soil and sediment) 

• Persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 158

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 79
Triclosan: Health Effects

• Health Assessment Status = 1

– 2008 OPP Risk Assessment

• RfD = 0.3 mg/kg-day 

– Critical Effect = Vomiting, diarrhea, loss of appetite

– NOAEL = 30 mg/kg-day; UF = 100

• HRL: 2,100 μg/L (non-cancer)

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 159

Triclosan: Occurrence

• USGS, National Reconnaissance of Emerging Contaminants (NREC), 

Ambient Ground Water, 1999-2004: 

– Median = 0.19 μg/L; < HRL (2,100 μg/L)

• USGS, NREC Ambient Surface Water, 1999-2004: 

– Median = 0.17 μg/L; < HRL (2,100 μg/L)

• USGS, Hopple, et al., 2008, Finished Water: 

– Maximum detect value = 0.065 μg/L; Maximum < HRL

• USGS, Kolpin , et al., 2002, Ambient Water: 

– 49 detections (maximum = 2.3 μg/L, median = 0.14 μg/L) out of 85 sites; Maximum 

detect (2.3 μg/L) < HRL (2,100 μg/L)

June 25, 2014 U.S. Environmental Protection Agency 160

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 80
Carbonyl Compounds

EPA Method 556.1 (Fast GC), 1999

Determination of carbonyl compounds in drinking water by fast gas 

chromatography, revision 1.0

June 25, 2014 U.S. Environmental Protection Agency 161

Analytes

• Formaldehyde (2) • Acetaldehyde (4)

Formaldehyde: Background

• Aliphatic aldehyde; used as a fungicide and tissue preservative

• Drinking water disinfection byproduct (from chlorination, 

ozonation)

• Present in smoked foods and in living systems as a metabolic 

intermediate

• Expected to be very mobile in water, based on chemical and 

physical properties

• The PBT Profiler (2009) predicts that 44% of formaldehyde will 

partition to water when modeled in a four-compartment system 

(water, air, soil and sediment)

• Not persistent in the environment

June 25, 2014 U.S. Environmental Protection Agency 162

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 81
Formaldehyde: Health Effects

• Health Assessment Status = 2

– 1990 IRIS Risk Assessment 

• RfD = 0.2 mg/kg-day

– Critical Effect = Reduced weight gain; decreased absolute heart, 

liver, testes and kidney weights; increased relative brain weights

– NOAEL = 15 mg/kg-day; UF = 100

• CCL 3 HRL: 1,400 μg/L (non-cancer)

• Sensitive populations: Deficiencies of folic acid and 

factors causing low activity of aldehyde reductase may 

increase the toxicity of formaldehyde

June 25, 2014 U.S. Environmental Protection Agency 163

Formaldehyde: Occurrence

• Disinfection By-product Information Collection Rule DBP-ICR, Finished 

Water, 1997-1998: 

– 126 detections (median = 7.6 μg/L) out of 227 sites using ozone; Maximum detect 

(30.6 μg/L) < HRL (1,400 μg/L) (only at plants with ozone)

• Chemical Update System / Inventory Update Reporting: 

– >1B lbs/yr in 2002; ≥1B lbs/yr in 2006

• Toxic Release Inventory – Total:

– 26,992,234 lbs/yr in 46 states in 2004; 19,381,048 lbs/yr in 45 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 164

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 82
Acetaldehyde: Background

• Aliphatic aldehyde; used as a pesticide and a food additive, 

also formed as a chemical intermediate in production of 

other substances

• Drinking water disinfection byproduct (from chlorination, 

ozonation)

• Expected to be moderately mobile to very mobile in water, 

based on chemical and physical properties

• The PBT Profiler (2009) predicts that 49% of acetaldehyde 

will partition to water when modeled in a four-compartment 

system (water, air, soil and sediment)

• Not persistent in the environment 

June 25, 2014 U.S. Environmental Protection Agency 165

Acetaldehyde: Health Effects

• Health Assessment Status = 4

– Registry of Toxic Effects of Chemical Substances (RTECS), 

2008

• RfD-like = 0.00333 mg/kg-day

– Critical Effect = Behavioral changes in motor activity (specific 

assay)

– LOAEL 10 mg/kg-day; Default UF = 3,000

• CCL 3 HRL: 23.3 μg/L (non-cancer)

• Sensitive populations: Individuals with polymorphism of 

the aldehyde dehydrogenase (ALDH) gene

June 25, 2014 U.S. Environmental Protection Agency 166

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 83
Acetaldehyde: Occurrence

• Disinfection By-Product Information Collection Rule (DBP-ICR), Finished 

Water, 1997-1998: 

– 27 detections (median = 7.4 μg/L) out of 236 sites using ozone; Maximum detect (18.3 

μg/L) < HRL (23.3 μg/L)

• California Department of Health Services, Finished Water (CAL DHS): 

– 3 detections (median = 2 μg/L) out of 8 sites; Maximum detect (24 μg/L) > HRL

• Chemical Update System / Inventory Update Reporting: 

– >100M – 500M lbs/yr in 2002; 100M – <500M lbs/yr in 2006

• Toxic Release Inventory – Total:

– 14,683,890 lbs/yr in 38 states in 2004; 9,926,083 lbs/yr in 38 states in 2010

June 25, 2014 U.S. Environmental Protection Agency 167

Cyanotoxins

June 25, 2014 U.S. Environmental Protection Agency 168

Draft EPA Method 544 (LC/MS/MS) 

Anticipated Publication Year 2014

Determination of microcystins and nodularin in drinking water by solid phase 

extraction and liquid chromatography/tandem mass spectrometry

Analytes

• Microcystin-LR (3) •Microcystin-LF

• Microcystin-RR •Microcystin-LY

• Microcystin-YR •Nodularin

• Microcystin-LA

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 84
Microcystin-LR: Background

• Cyanotoxin (toxin produced and released by 

cyanobacteria) that targets the liver

• Insufficient data to characterize mobility in 

water or environmental persistence

June 25, 2014 U.S. Environmental Protection Agency 169

Microcystin-LR: Health Effects

• Health Assessment Status = 3

– Single Study (Ueno, Makita, Nagata et al. 1999)

• RfD-like = 0.000003 mg/kg-day

– Critical Effect = Liver effects

– NOAEL = 0.003 mg/kg-day; Default UF = 1,000

• CCL 3 HRL: 0.021 μg/L (non-cancer)

• Sensitive populations: None identified

June 25, 2014 U.S. Environmental Protection Agency 170

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 85
Microcystin-LR: Occurrence

• US and Canadian drinking water (bloom area, source, finished water):

– 542 detections out of 677 sites; Typical maximum (0.1 μg/L) < HRL (0.021 μg/L)

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 171

Cyanotoxins

June 25, 2014 U.S. Environmental Protection Agency 172

Draft EPA Method 545 (LC/ESI-MS/MS)

Anticipated Publication Year 2014

Determination of cylindrospermopsin and anatoxin-a in drinking water by liquid 

chromatography electrospray ionization tandem mass spectrometry

Analytes

• Anatoxin-a (4) • Cylindrospermopsin (3)

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 86
Anatoxin-a: Background

• Cyanotoxin (toxin produced and released by 

cyanobacteria) that targets the nervous system 

• Insufficient data to characterize mobility in water or 

environmental persistence

June 25, 2014 U.S. Environmental Protection Agency 173

Anatoxin-a: Health Effects

• Health Assessment Status = 4

– Single Study (Astrachan and Archer, 1981)

• RfD-like = 0.0005 mg/kg-day

– Critical Effect = Mortality in rats (7-day)

– NOAEL = 0.5 mg/kg-day; Default UF = 1,000

• CCL 3 HRL: 3.5 μg/L (non-cancer)

• Sensitive populations: People using anticholinergic 

agents for therapeutic purposes could be at risk of 

increased side effects after exposure to anatoxin-a, due 

to the potential for the additivity of adverse effects 

June 25, 2014 U.S. Environmental Protection Agency 174

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 87
Anatoxin-a: Occurrence

• CyanoHABs - The Florida Experience, 2000:

– Maximum detect (~10 μg/L); Maximum detect > HRL (3.5 μg/L)

• UCMR 1 Meeting summary: 

– 4% detection rate in Lake Champlain

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 175

Cylindrospermopsin: Background

• Cyanotoxin (toxin produced and released by 

cyanobacteria) that affects the liver and kidney

• Insufficient data to characterize mobility in water or 

environmental persistence

June 25, 2014 U.S. Environmental Protection Agency 176

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 88
Cylindrospermopsin: Health Effects

• Health Assessment Status = 3

– Single Study (Humpage and Falconer, 2003)

• RfD-like = 0.00003 mg/kg-day

– Critical Effect = Increased kidney weight

– NOAEL = 0.03 mg/kg-day; Default UF = 1,000

• CCL 3 HRL: 0.21 μg/L (non-cancer)

• Sensitive populations: Children; individuals with liver or 

kidney disease

June 25, 2014 U.S. Environmental Protection Agency 177

Cylindrospermopsin: Occurrence

• CyanoHABs - The Florida Experience, 2000:

– Maximum detect (~100 μg/L); Maximum detect > HRL (0.21 μg/L)

• UCMR 1 Meeting summary: 

– Maximum detect (90 μg/L); Maximum detect > HRL (0.21 μg/L)

• Chemical Update System / Inventory Update Reporting: 

– No data in 2002 or 2006

• Toxic Release Inventory – Total:

– No data in 2004 or 2010

June 25, 2014 U.S. Environmental Protection Agency 178

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 89
Legionella pneumophila 

June 25, 2014 U.S. Environmental Protection Agency 179

Under Evaluation: Potential methods being investigated

Analytes

• Legionella pneumophila

Legionella: Background

• Legionella bacteria are aerobic gram-negative rods associated with 

respiratory infections

• Legionella are ubiquitous in fresh and marine waters; exist in 

varied temperatures, pH levels and nutrient and oxygen contents

• EPA is leading a multi-agency taskforce to develop a document 

characterizing the effectiveness of available treatment technologies 

for control of Legionella as well as the regulatory implications for 

consecutive systems that may become PWSs after installing 

additional treatment. The document is scheduled to be completed 

by Spring 2015

June 25, 2014 U.S. Environmental Protection Agency 180

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 90
Legionella: Health Effects

• Legionellosis

– Major risk factors: immunosuppression, smoking, travel, use of 

undisinfected well water, chronic heart or lung disease and chronic 

renal failure 

– Community or hospital acquired legionellosis can occur 

– Approximately 1,000-2,000 cases are reported to CDC each year

– Prompt diagnosis and treatment results in 95-99% recovery rates

– Mortality in untreated cases is approximately 15% of previously 

healthy patients and 75% of severely immunocompromised patients

• Pontiac Fever

– Resembles an acute allergic reaction

– Self-limiting; no specific treatment is advised and hospitalization is not 

required

June 25, 2014 U.S. Environmental Protection Agency 181

Legionella: Occurrence

• Can colonize plumbing fixtures, hot water tanks, warm water spas 

and cooling towers

• May have evolved a symbiotic relationship with free-living 

amoebae, which may facilitate movement and colonization of 

domestic and industrial water systems 

• Colonization of hot water systems in hospitals has resulted in 

numerous hospital outbreaks

• Community acquired cases are typically associated with cooling 

towers or untreated well water exposures

• 52 documented waterborne disease outbreaks affecting 225 

people caused by L. pneumophila as reported by CDC between 

1990 and 2010

– Outbreaks associated with drinking water exposure mostly due to premise 

plumbing colonization, which is not under jurisdiction of the water utility 

June 25, 2014 U.S. Environmental Protection Agency 182

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 91
Presenter

Melissa Simic, USEPA

June 25, 2014 U.S. Environmental Protection Agency 183

Other UCMR 4 Contaminants Under 

Consideration

• Nitrate/Nitrite (currently regulated)

– Nitrate and nitrite levels may increase in the distribution 

system, especially when chloramines are used as residual 

disinfectants 

– Currently, monitoring is only required at the entry point to 

the distribution system and is not required in the distribution 

system or for all consecutive systems

– UCMR 4 data could be used to better characterize the 

exposure of nitrite and nitrate in the distribution system on a 

national scale

June 25, 2014 U.S. Environmental Protection Agency 184

Other UCMR 4 Contaminants 

Under Consideration

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 92
Other UCMR 4 Contaminants 

Under Consideration

• 4 unregulated brominated DBPs (bromochloroacetic acid, 

bromodichloroacetic acid, dibromochloroacetic acid, and tribromoacetic acid)

– Monitor at Stage 2 DBPR compliance locations

– Brominated haloacetic acids (HAAs) may pose higher 

health risks than chlorinated species

– UCMR 4 data could help inform brominated HAA 

occurrence and exposure relative to the regulated HAA5 

(i.e., monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, 

monobromoacetic acid, dibromoacetic acid)

June 25, 2014 U.S. Environmental Protection Agency 185

Appendices

June 25, 2014 U.S. Environmental Protection Agency 186

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 93
June 25, 2014 U.S. Environmental Protection Agency 187

Appendix A: Unregulated CCL 3 Contaminants

106 Chemicals and 12 Microbes

Chemicals

1,1,1,2-Tetrachloroethane 

1,1-Dichloroethane 

1,2,3-Trichloropropane 

1,3-Butadiene 

1,3-Dinitrobenzene 

1,4-Dioxane 

17 alpha-Estradiol 

1-Butanol 

2-Methoxyethanol 

2-Propen-1-ol 

3-Hydroxycarbofuran (degradate) 

4,4'-Methylenedianiline 

Acephate 

Acetaldehyde

Acetamide 

Acetochlor 

Acetochlor ethanesulfonic acid (ESA) 

Acetochlor oxanilic acid (OA) 

Acrolein 

Alachlor ethanesulfonic acid (ESA)

Alachlor oxanilic acid (OA) 

alpha-Hexachlorocyclohexane

Anatoxin-a

Aniline 

Bensulide 

Benzyl chloride 

Butylated hydroxyanisole 

Captan 

Chlorate (also D-DBP) 

Chloromethane (Methyl chloride) 

Clethodim 

Cobalt 

Cumene hydroperoxide 

Cylindrospermopsin

Dicrotophos 

Dimethipin 

Dimethoate 

Disulfoton 

Diuron 

Equilenin

Equilin 

Erythromycin 

Estradiol (17-beta) 

Estriol 

Estrone 

Ethinyl Estradiol (17-alpha) 

Ethoprop 

Ethylene glycol 

Ethylene oxide 

Ethylene thiourea 

Fenamiphos 

Formaldehyde 

Germanium 

Halon 1011 (Bromochloromethane) 

HCFC-22 

Hexane 

Hydrazine 

Mestranol 

Methamidophos 

Methyl bromide (Bromomethane)

 

Methyl tert-butyl ether 

Metolachlor 

Metolachlor ethanesulfonic acid (ESA)

Metolachlor oxanilic acid (OA) 

Microcystin-LR

Molinate 

Molybdenum 

Nitrobenzene 

Nitroglycerin 

N-Methyl-2-pyrrolidone 

N-Nitrosodiethylamine (NDEA) 

N-nitrosodimethylamine (NDMA) 

N-Nitroso-di-n-propylamine (NDPA) 

N-Nitrosodiphenylamine

N-nitrosopyrrolidine (NPYR) 

Norethindrone (19-Norethisterone) 

n-Propylbenzene

o-Toluidine

Oxirane, methylOxydemeton-methyl 

Oxyfluorfen

Perchlorate

Perfluorooctane sulfonic acid (PFOS)

Perfluorooctanoic acid (PFOA) 

Permethrin (cis, trans)

Profenofos

Quinoline

RDX 

sec-Butylbenzene 

Strontium 

Tebuconazole

Tebufenozide 

Tellurium 

Terbufos 

Terbufos sulfone 

Thiodicarb

Thiophanate-methyl 

Toluene diisocyanate 

Tribufos 

Triethylamine 

Triphenyltin hydroxide (TPTH) 

Urethane 

Vanadium 

Vinclozolin 

Ziram 

Microbes

Adenovirus 

Caliciviruses 

Campylobacter jejuni 

Enterovirus 

Escherichia coli (0157) 

Helicobacter pylori 

Hepatitis A virus 

Legionella pneumophila

Mycobacterium avium 

Naegleria fowleri 

Salmonella enterica

Shigella sonnei

UCMR 4 Candidates

June 25, 2014 U.S. Environmental Protection Agency 188

Appendix B: CCL 4 Nominations

Chemicals

3-chloro-4-dichloromethyl-5-hydroxy-2(5H)-

furanone1,1,1,2-Tetrachloroethane 

Alkylphenol mono- to tri-oxylates

Amoxicillin 

Azinphos-methyl 

Bacitracin zinc 

Bentazone

Benzyl butyl phthalate 

Bisphenol A

Bromoxynil

Carbaryl 

Chlorothalonil

Chlorpyrifos

Dibutyl phthalate 

Dicamba

Dichlorvos 

Dicofol 

Dicyclohexyl phthalate

Diethyl phthalate

Di-isononyl phthalate 

Dimethyl phthalate 

Di-n-octyl phthalate

Endosulfan 

Fluometuron

Linezolid

Linuron 

Malathion

Manganese

Methicillin 

Methyl parathion

Nonylphenol 

Nonylphenol ethoxylate 

Octylphenol

Octylphenol ethoxylate 

Oxacillin

Penicillin 

Phosmet

Progesterone 

Spiramycin

Testosterone 

Trichlorfon 

Triclocarban 

Triclosan 

Tylosin 

Vancomycin

Virginiamycin 

Chlorate (also D-DBP) 

Chloromethane (Methyl chloride) 

Clethodim 

Cobalt 

Cumene hydroperoxide 

Microbes

Toxoplasma gondii

Vibrio cholerae

Note: There were a total of 59 unique nominations for CCL 4. Only 48 are presented here because eleven contaminants were 

removed for either having an existing NPDWR or are already on CCL 3. 

UCMR 4 Candidates

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 94
June 25, 2014 U.S. Environmental Protection Agency 189

Revisions to the Unregulated 

Contaminant Monitoring Rule 

(UCMR 4) for Public Water Systems

Public Stakeholder Meeting 

and Webinar

Afternoon Break

Resume at 3:15 p.m.

190

Approval of Laboratories 

Supporting UCMR 4

Public Meeting and Webinar

Washington D.C.

June 25th, 2014 – 3:15 p.m.

Brenda Parris

USEPA, OGWDW, SRMD

Technical Support Center

Cincinnati, OH

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 95
Overview

• Expected approach to the UCMR 4 

Laboratory Approval Program 

• Maintaining approval

June 25, 2014 U.S. Environmental Protection Agency 191

General Expectations

• Laboratory Approval Program expected to be similar 

to the process used in UCMR 3

• Water systems would need to use EPA UCMRapproved laboratories for analysis

• Labs would need to meet the required equipment, 

laboratory performance and data reporting criteria to 

become approved

• Labs would still need to be approved to support 

UCMR 4 even if already certified by state, primacy 

entity or accredited through the National 

Environmental Accreditation Program (NELAP) for a 

particular method being used for compliance 

monitoring 

June 25, 2014 U.S. Environmental Protection Agency 192

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 96
General Procedure

• Step 1: Request to participate and register

• Step 2: Application

• Step 3: EPA review of application

• Step 4: Proficiency Testing

• Step 5: EPA approval

June 25, 2014 U.S. Environmental Protection Agency 193

Step 1

• Request to participate and register

– Submit a written participation request to EPA 

Laboratory Approval Coordinator

– EPA provides registration material

– Submit complete registration material within 90 

days of Final Rule publication in Federal Register

– EPA provides a custom application package 

based on registration information

June 25, 2014 U.S. Environmental Protection Agency 194

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 97
Step 2

• Application Package

– Separate application for each method

– Lab would receive a copy of the Laboratory 

Approval Manual

– Completed package would be submitted within 

210 days of publication of the Final Rule in the 

Federal Register

June 25, 2014 U.S. Environmental Protection Agency 195

Laboratory Approval Manual

• Procedures for obtaining UCMR approval and procedures for 

revocation of approval

• Quality Assurance requirements

• Quality Control requirements

– Initial demonstration of capability

– Initial calibration

– Continuing calibration checks

– Surrogate and internal standard criteria

– Reagent blanks and fortified blanks

– Quality control samples

– Spiked field samples

– Field blank criteria (if required by the method)

• Sample handling requirements

June 25, 2014 U.S. Environmental Protection Agency 196

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 98
Step 2 continued

• Completed application package anticipated to 

include:

– Precision, accuracy and minimum reporting level 

(MRL) studies with documentation

– Documentation of certification or accreditation of 

drinking water compliance analyses/selected 

methods as requested

– Personnel and quality assurance information

– Description of analytical equipment and sample 

handling procedures

June 25, 2014 U.S. Environmental Protection Agency 197

Step 3

• Review of Application Package

– EPA would review the package and could request 

more information

– Email notifying lab would be sent following EPA’s 

confirmation of successful completion of the 

application package

– Once the application has been accepted, the lab 

could participate in the corresponding PT studies

June 25, 2014 U.S. Environmental Protection Agency 198

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 99
Step 4

• Proficiency Testing

– EPA would provide PT samples

– Labs would analyze PT sample(s) for each 

method

– Labs would likely have several opportunities to 

analyze PT samples

– Only one successful analysis of PT samples per 

method would be required

June 25, 2014 U.S. Environmental Protection Agency 199

Step 5

• EPA Approval

– Once all steps are completed, EPA would grant 

formal written approval (for each method, as 

appropriate)

June 25, 2014 U.S. Environmental Protection Agency 200

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 100
Maintaining Approval

• Adhere to quality assurance/quality control (QA/QC) 

measures in both the methods and the Laboratory 

Approval Manual

• Post occurrence data and required QC data via the 

Safe Drinking Water Accession and Review System 

(SDWARS) within prescribed timeframe

• Participate and pass on-site and/or paper audits

• Respond to requests for data outside of SDWARS

June 25, 2014 U.S. Environmental Protection Agency 201

June 25, 2014 U.S. Environmental Protection Agency 202

Revisions to the Unregulated 

Contaminant Monitoring Rule 

(UCMR 4) for Public Water Systems

Public Presentations – 3:45 p.m.

Pre-registered speakers only

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 101
June 25, 2014 U.S. Environmental Protection Agency 203

Revisions to the Unregulated 

Contaminant Monitoring Rule 

(UCMR 4) for Public Water Systems

Discussion

June 25, 2014 U.S. Environmental Protection Agency 204

Closing Remarks

• On-site attendees must turn in any door keycards to the 

sign-in desk.

• Meeting materials were sent to all registered 

participants; if you did not receive a copy, please email 

UCMRwebinar@cadmusgroup.com and we will send 

you a copy.

Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 4) Meeting Presentations 102