Regulatory Determinations fo

Thi d D i ki W t C t Thi

r

d

D

r

i

nking 

W

a

ter 

Con

tam

Candidate List 

Stakeholder Meeting

Washin

gton D.C.

June 16th, 2011

USEPA 

Office of Ground Water and Drinking Wat
Regulatory Determination 3 Agen

1. Provide Background

– O i f SDWA R l t P Overview o

f SDWA

Regula

tory 

Processes

– Statutory criteria for Regulatory Determinations & Potentia– Previous CCLs and Regulatory Determinations

2. Discuss Approach for Regulatory Determination 3 (R

– Approach to screen/identify potential contaminants for Reg– List of potential contaminants being evaluated further for R

List of potential contaminants being evaluated further for R

– Information considered in evaluating the three SDWA statu

3. Discuss Health & Occurrence Information for S

pecific 

Contaminants Being Evaluated for RegDet 3

4. Provide Next Steps and Discuss Remaining Question

June 16, 2011 U.S. Environmental Protection Agency 
Overview of the SDWA Regulat

Processes

, the Contaminant Cand

List (CCL) and Regulatory 

Determinations Process 

Wynne Miller, USEPA

June 16, 2011 U.S. Environmental Protection Agency 
SDWA Regulatory Processes

Contaminant Candidate List (CCL) – List of unregulated contaminants known or may occur in drinking water; publish every 5 years known or may occur in drinking water; publish every

5 years.

Regulatory Determinations – Decisions on whether to regulate CCL cowith a drinkin

g yy water standard; make decisions on at least 5 ever

y 5 

yea

consider 3 SDWA criteria. If decide to regulate, SDWA requires EPA to months and finalize in 18 months.Unregulated Contaminant Monitoring Unregulated Contaminant Monitoring

– Process to monitor at least 30 

Process to monitor at least 30 

unregulated contaminants every 5 years. Regulation Development - If regulate, SDWA requires that we evaluate

number of factors in the standard setting process (health analytical/treanumber of factors in the standard setting process (health, analytical/trea

feasibility, costs/benefits, etc). Six Year Review – Every 6 years, review and (if appropriate) revise the 

revision must maintain or improve public health protection If revise we revision must maintain or improve public health protection. If revise, we 

regulation development process again and evaluate a number of factors

June 16, 2011 U.S. Environmental Protection Agency 
General Flow of SDWA Regulatory Pr

List unregulated 

contaminants*

“Contaminant 

Candidate List” Determine whether at least five need a at least five need

a

drinking water 

standard*

“Regulatory 

D t i ti ”

Develop or revise 

the drinking water 

standard

*

List and collect 

monitoring data at

If yes

w

D

e

terminations” standard

“Regulation 

Development”

monitoring data at

least 30 unregulated 

contaminants 

“Unregulated 

Contaminant

*F th th t lik t h i d ifi it d fid i th t f ti 

“S

Monitoring”

Opportunity for public comment

*For these three stages, we like to 

have increase

d specifi

city an

d confidence in the type of supportin

used (e.g. health and occurrence). SDWA requires that we used best available data to make our de

June 16, 2011 U.S. Environmental Protection Agency 
Three Regulatory Determination Cr

SDWA req ires EPA to consider the follo ing criteSDWA req

uires EPA to consider the follo

wing crite

evaluating whether to regulate a contaminant:

1) The contaminant may have an adverse effect on the

2) The contaminant is known to occur or there is 

substantial likelihood that the contaminant will

1) The contaminant may have an adverse effect on the

health of persons;

substantial likelihood that the contaminant will

occur in public water systems with a frequency and at levels of public health concern; and

3) I h l j d f h Ad i i l i f 3)

In the so

le 

j

u

dgment o

f the Adm

in

istrator, regu

lation o

f s

contaminant presents a meaningful opportunity for health 

reduction for persons served by public water systems.

*SDWA Sec

June 16, 2011 U.S. Environmental Protection Agency 
Potential Outcome of Determinatio

• No Regulatory Determination No Regulatory Determination

– Insufficient data to assess contaminant on three criteria

• Positive Determination

– Answer “yes” decision for “all three” criteria – Begin process to develop a drinking water regulation Begin process to develop

a drinking water regulation

• Negative Determination 

– Answer “no” for “any one” of the three criteria– Do not develop a drinking water regulation– Develo

pin

g a Health Advisor

y is a non-re

gulator

y o

ption

pg y g yp

June 16, 2011 U.S. Environmental Protection Agency
CCL & Reg y ulatory Determinations Ti

CCL3:

116 Contaminants CCL1: CCL2:

2003 2008

116 Contaminants

See Appendix A

60 Contaminants 51 Contaminants

Regulatory Regulatory

2009

1998 2005

Determination 1 Determination 2 

9 Negative Determinations

0 Positive Determinations

11 Negative Determinations

0 Positive Determinations

P

d d

June 16, 2011 U.S. Environmental Protection Agency 
Overview of Approach Used t

Evaluate Potential Contaminants 

Regulatory Determinations 3

Z B i USEPA Zeno 

B

ain, USEPA

June 16, 2011 U.S. Environmental Protection Agency
Overall Approach Used to Evaluate CCL 

Contaminants for Re

g y ulatory Determinatio

Regulatory Determ

CCL 3 Contaminants

Health Effects and Occurrence Evaluation

• Is an Agency-approved assessment likely

Yes

n Phase

Potenti

Candidates 

Regulato

Determinations 

• Is an Agency-approved assessment likely

to be available to determine whether a potential adverse health effect exists and a potential health reference level (HRL) within a timeframe to consider for Reg Det? 

a Evaluatio Statutory criteria to make a regu

(SDWA 1412(b)(2)(B)(ii)): • Likely to cause an adverse hum

Yes 

-- And --

• Are data available to evaluate known or likely occurrence (level and frequency) in public water systems (PWSs)?

n and Data• Known or likely to occur at a le

of concern at PWSs? • Will regulation present a meanfor health risk reduction?

Not appropriate to consider

No

Informatio 

Consider for regulation Not appropriate to consider

for Regulatory Determination

at this time.

Publish FR notice with preliminary 

and rationale for the determination

June 16, 2011 U.S. Environmental Protection Agency 
RegDet 3 Prioritization Proces

CCL 3: 116 Contaminants

56 • Health effects assessment may be com

• National finished water occurrence da

N ti l fi i h d t 

32

(Sh t Li t)

• on-national fi

nis

h

e

d water occurrenc

• Health effects assessment may be com

• National finished water occurrence da• Non-national finished water occurrenc

X

(Short Li

st) levels of potential public health concer

• Health effects assessment will be com

• National finished water occurrence da

• Non national finished water occurrenc

Make no 

d t i ti f

-national finished water occurrenc

levels and frequency of potential publi

X Contaminants continue in t

d

e

termination 

f

o

r R l t D t i ti P

116 - X

Regula

tory 

D

e

termination 

P

June 16, 2011 U.S. Environmental Protection Agency 
Short List of Contaminants Being Conside

Evaluated Further for Re

gulatory Determin

• Nitrosamines (5)

- N-nitrosodimethylamine (NDMA) 

N it di th l i (NDEA)

g y

• 1,4-Dioxane• Methyl Tertiary Butyl Ethe

-

N-nitrosodi

eth

ylamine (NDEA), 

- N-nitrosodi-n-propylamine (NDPA) - N-nitrosopyrrolidine (NPYR) -

N

-nitrosodiphenylamine (NDPhA)

• Nitrobenzene• PFOS and PFOA• RDX

N nitrosodiphenylamine (NDPhA) • Dimethoate

• Chlorate• Molybdenum• Strontium

Vanadi m

Dimethoate

• Disulfoton• Diuron• Molinate

• Vanadi

u

m T b f d T b f S 

• 1,1,1,2-Tetrachloroethane• 1,2,3-Trichloropropane (TCP)• 1,3-Dinitrobenzene

• 

Ter

b

u

fos an

d

Ter

b

u

fos 

S

u

• Acetochlor & ESA and OA • Alachlor ESA & OA Degra• Metolachlor & ESA and OA 

June 16, 2011 U.S. Environmental Protection Agency 
Overall Approach Used to Evaluate CCL 

Contaminants for Re

g y ulatory Determinati

Regulatory Determ

CCL 3 Contaminants

Health Effects and Occurrence Evaluation

• Is an Agency-approved assessment likely

Yes

n Phase

Potenti

Candidates 

Regulato

Determinations 

Is an Agency approved assessment likely

to be available to determine whether a potential adverse health effect exists and a potential health reference level (HRL) within a timeframe to consider for Reg Det? 

a Evaluatio Statutory criteria to make a regu

(SDWA 1412(b)(2)(B)(ii)): • Likely to cause an adverse hum

Yes 

-- And --

• Are data available to evaluate known or likely occurrence (level and frequency) in public water systems (PWSs)?

n and Data• Known or likely to occur at a le

of concern at PWSs? • Will regulation present a meanfor health risk reduction?

Not appropriate to consider

No

Informatio 

Consider for regulation Not appropriate to consider

for Regulatory Determination

at this time.

Publish FR notice with preliminary 

and rationale for the determination

June 16, 2011 U.S. Environmental Protection Agency 
Evaluation of Statutory Criteria

# Statutory Criteria Information To Consider During E

• Potential adverse health effect(s) (e g cance

1 Adverse effect on the health of humans?

Potential adverse health effect(s) (e.g. cance

damage) and level at which effect occurs (i.econcern)

Known or likely to • National monitoring data from PWSs and whe

2

Known or likely to

occur in PWSs at a frequency and level of concern?

• National monitoring data from PWSs and whe

drinking water at the health level of concern

• Other sources of information (e.g. state water 

levels in source waters, how much is used/pr

Meaningful opportunity for health

Consider variety of factors which include:• Number of people who may be exposed to th

from drinking water (served by PWSs)

S iti l ti ( hild ld l 

3

opportunity for health

risk reduction for persons served by PWSs?

• Sensitive populations (e.g. children, elderly, c

immune systems)

• Extent of occurrence• Ex

p ( 

osure from water versus other sources (e

primarily for non-cancer 

June 16, 2011 U.S. Environmental Protection Agency 
Sources of Health Data and Informa

• Identify p gg y ( , 

 recent or im

pendin

g A

genc

y risk assessment (IRIS,OPP 

• Conduct literature searches (if older assessment)• Identify the following:

– Potential health effects– Reference Dose (RfD) or other non-cancer health value, and/or – Cancer slope factor

• Calculate benchmark value or health reference level to evaluate 

– Use 10-6 risk level for carcinogens

– Use lifetime health advisory value for non-carcinogens along with a 2

source contribution (RSC)

• Note: For today’s meeting, using health values derived for the 2009 CCL

evaluating the availability and sufficiency of health information for RegDesome health values could change. In addition, some are in the process o

June 16, 2011 U.S. Environmental Protection Agency 
Sources of Occurrence Data and Info

• Unregulated Contaminant Monitoring Regulation (UCMR

– UCMR 1 Assessment (2001 – 2003) – UCMR 2 Assessment (2008 – 2010)

• Unregulated Contaminant Monitoring (UCM)

– Round 1 (1988 – 1992)– Round 2 (1993 – 1997)

• National Inorganics and Radionuclides Survey (NIRS) (1• Occurrence results presented as the number/percent of s

with l ti l lt > ifi d t ti ( 

ith an analytical result

> a specifi

e

d concen

tration 

(e.g., 

(detection), > 1⁄2 HRL or HRL, etc.). 

June 16, 2011 U.S. Environmental Protection Agency 
Sources of Occurrence Data an

Information (cont.)

• State Data - Available on a contaminant specific basis• DBP Information Collection Rule (ICR) - July 1997 – Dec 1998 • US Geological Survey

– N ti l W t Q lit A t P (NAWQA) N

ational W

ater 

Quality 

Assessment Program (NAWQA)

– National Random & Focused Source Water Surveys (with AWWA– Special reports

• USDA Pesticide Data Program (PDP)• Community Water System Surveys• Consumer Confidence Reports• Environmental Working Group data• Toxics Release Inventory (TRI) Toxics Release Inventory (TRI)• Production Data (e.g. Chemical Update System/Inventory Upda

Reporting Program (CUS/IUR))

• OPP Reregistration Eligibility Document (RED) 

– Data from pesticide registrants Data from pesticide registrants

• Other specialized studies and literature 

June 16, 2011 U.S. Environmental Protection Agency 
Drinking Water Strategy

June 16, 2011 U.S. Environmental Protection Agency 
Drinking Water Strategy

March 2010 Administrator AnnounceMarch 2010 Administrator Announce

1. Address contaminants as groups rath

one at a time one at

a time.

2. Foster development of new drinking wate

treatment technolo

gies. 

3. Use the authority of multiple statutes to h

protect drinking water.

4. Partner with states to share more comple

from monitoring at public water systems.

June 16, 2011 U.S. Environmental Protection Agency 
Outreach for Addressing 

Co ta a ts as G oups ntamin

a

nts as

G

roups

• Informal Planning Meeting (June 7)• 4 Listening Sessions

9 J 21 une

– Chi IL cago, IL

9 Aug 11 – Cincinnati, OH9 Aug 16 – Washington, DC9 Aug 19

– Rancho Cucamonga CA Rancho Cucamonga, CA

• National Drinking Water Advisory Council Consultation (July 2• Web Dialogue (July 28-29) and Web Forum (July 2010 to Jan • Stakeholder Meetin

g( p ) Se

pt 21)

• ASDWA Annual Meeting (Oct 18-21)• National Drinking Water Advisory Council Consultation (Dec 8 June 16, 2011 U.S. Environmental Protection Agency 
What did we hear from outreach ef

• Public health protection should be of paramount importan• Consider the followin

g:

– Health effect endpoints in grouping of contaminants– Treatment feasibility to identify/address contaminant groups– Analytical methods and/or use surrogates– Occurrence and co Occurrence and co

-occurrence of contaminants occurrence of contaminants

– Addressing groups of contaminants at their source

• Evaluate app y roaches used b

y States and other countries.

• Consider non-regulatory approaches (e.g. health advisories

June 16, 2011 U.S. Environmental Protection Agency 
Potential Factors & Preliminary Eva

• Sept 2010 DWS Stakeholder Meeting Sept 2010 DWS Stakeholder Meeting - Identified four fact

Identified four fact

consider when evaluating groups: 

– Has similar health effect endpoint– Removed by common treatment or control processes Removed by common treatment or control processes– Measured by common analytical method(s)– [Known or likely occurrence and co-occurrence]

• “Promising” groups likely to have multiple factors in comm• February 2011 – announced that EPA would evaluate carc

Volatile Organic Compounds (cVOCs) as the first group foVolatile Organic Compounds (cVOCs) as the first group fo

effort (several listed on CCL3 and included in today’s disc

• Se

p g t 2010 DWS Stakeholder Meetin

g

– EPA indicated tha

evaluate nitrosamines as a group; addressing as part of R

June 16, 2011 U.S. Environmental Protection Agency 
Contaminants Being Considered 

E l t d f R l t D t i Evalua

t

e

d

for 

Regula

tory 

D

e

termina

Z B i USEPA

• Nitrosamines

N nitrosodimethylamine (NDMA)

Zeno 

B

ain, USEPA

-

N

-nitrosodimethylamine (NDMA)

- N-nitrosodiethylamine (NDEA) - N-nitrosodi-n-propylamine (NDPA) -

N

-nitrosopyrrolidine (NPYR) nitrosopyrrolidine (NPYR)

- N-nitrosodiphenylamine (NDPhA)

• Chlorate

June 16, 2011 U.S. Environmental Protection Agency 
Nitrosamines: Background

Nitrosamines Considered during Nitrosamines Considered during Included on Moni

Development of CCL3

Included on

CCL3

Moni

under U

N-nitrosodimeth

y () lamine (NDMA) Yes Ye

N-nitrosodiethylamine (NDEA) Yes YeN

-nitrosodi nitrosodi

-

n

-propylamine (NDPA) propylamine (NDPA) Yes Ye

N-nitrosopyrrolidine (NPYR) Yes YeN

-nitrosodiphenylamine (NDPhA) nitrosodiphenylamine (NDPhA) Yes N

N-nitrosomethylethylamine (NMEA) No YeN-nit di roso -n-b t l i (NDBA) b

u

t

ylamine (NDBA)

N

o

Ye

June 16, 2011 U.S. Environmental Protection Agency 
Nitrosamines: Background (con

• Byproduct of manufacturing processes 

rocket fuels, foods, beverages, & pestic

• Discharges of municipal wastewater• By-products from water treatment, partic

disinfection with chloramines

June 16, 2011 U.S. Environmental Protection Agency 
CCL3 Health Reference Levels

• 1986 IRIS Risk • Revised Slope 

developed for R

Nitrosamine 

Compounds

IRIS Cancer 

Slope Factor 

(mg/kg/day)

CCL3 

HRL: 

Cancer

(ng/L)* developed for R

Determination 3 EPA (2005) gui

NDMA 51 0.7

NDEA 150 0.2NPYR 2 1 20 • Age Dependant 

Factors (ADAF) in determining t

l lif

NPYR

2.1 20

NDPA 7.0 5

NDPhA 0.0049 7,100

early life expos

NDBA 5.4 6

NMEA 22 2

June 16, 2011 U.S. Environmental Protection Agency 

* Based on 10-6 cancer risk level. 
Nitrosamine: Cancer Health Effe

Nitrosamine Tumors Animals 

Compounds

Tumors Animals 

NDMA Liver, lung, kidney, nasal cavity & bile duct Rats, mice, hamster

rabbits, guinea pigs 

NDEA Liver, esophageal, lung, tracheal, 

bronchial, forestomach & nasal cavity

Mice, hamsters, guinea pigs, rabbits, dogs, monkey

NPYR Li t t l l t h l Liver, testes, laryngeal, trac

heal, Rt i h t 

& nasal

R

ats, mice, 

hamster

NDBA Liver, esophageal & bladder Rats & mice 

NMEA Liver esophageal renal lung & Liver, esophageal, renal, lung

& Rats & hamsters 

nasal 

Rats

& hamsters 

NDPA Liver, nasal cavity, esophagus, 

tongue, forestomach & lung

Rats & mice 

June 16, 2011 U.S. Environmental Protection Agency 
Nitrosamines in the Diet

• Found in some food products

– Cured meats and fish– Beer– Smoked products 

• Can form endogenously by nitrosation of dietary • Processing changes since the 1970 Processing changes since the 1970 s’ have resu

have resu

– Reduced nitrate and nitrite for curing meat and fish– Addition of chemicals that inhibit formation–

Bette te pe atu e co t o s e d y g g p ote 

r te

mpe

ratu

r

e co

n

t

r

ols wh

en 

d

r

yin

g hi

gh 

p

rotein 

• Levels of dietary nitrosamines have decreased

June 16, 2011 U.S. Environmental Protection Agency 
NDMA: Levels Found in Foods

*Product Year Range Mean Cured Fish(n

g/g)

1971 nd to 26 

( g g) 2001-2005 0.54 – 1.99Cured Meat(ng/g)

1975 nd to 35 2004 7.3

Bacon 1973 nd to 30 (ng/g) 1993-1994 nd to 3Cheese(ng/g)

1978 nd to 68 1995 nd to 0.84 0.28

Dried Milk(ng/g)

1981 0.45 to 4.2 1.691995 nd to 0.18

**Formula Powder (ng/g)

1980-1981 0.56

Powder (ng/g) 1995 nd (<0 05) nd (<0.05)Beer(ng/L)

1978-1979 nd to 78,0002000-2006 nd to 660

nd = non detect

*Table 3 from Schafer et al. (2010)

**Formula powder is a chart addition; Year 1980-1981 data: Fristachi and Rice (2007)

Year 1995 data: Oliveira et al. (1995)

June 16, 2011 U.S. Environmental Protection Agency 
Nitrosamines: Occurrence

Detections in UCMR 2 as of March 1 20

Nitrosamine 

Compounds

MRL

(ng/L)

#Samples* 

with 

#Systems* 

with 

P

S

Detections in UCMR

2 as of March

1, 20

Compounds (ng/L) Detection Detection 

NDMA 2 1,787 (10%) 324 (27%) 

NDEA 5 46 (0.3%) 26 (2.2%) 

NPYR 2 41 (0 2%) 21 (1 8%) 

(0.2%) (1.8%)

NDBA 4

9

(0.05%)

5

(0.4%) 

3

3 NMEA 3 (0.02%) (0.3%) 

NDPA 7 0 0 

June 16, 2011 U.S. Environmental Protection Agency 

* Approximately 17,900 samples from 1,200 Public Water Systems
Nitrosamines: Occurrence (con

Detections of Nitrosamines by Disinfecta

#Samples 

with 

Detection

#Detections 

from Samples 

with Chlorine

#Detections from 

Samples with 

Chloramines

#

NDMA 1,787 295

(up to 85 ng/L)

996

(up to 630 ng/L)

(up 

NDEA 46 27

9 

(up to 50 ng/L)

9

(up to 100 ng/L)

(u

NPYR 41 14

(u

p to 24 n

g/L)

24

(u

p to 17 n

g/L)

(p g ) (p g ) (

u

NDBA 9 9

(up to 21 ng/L)

0 

NMEA 3 3 0 

(up to 5 ng/L)

June 16, 2011 U.S. Environmental Protection Agency
Nitrosamines: Occurrence (con

State of California Drinkin

g Water D

Compounds Monitoring Result

NDMA • 1,531 de

tecti

o

n

s

of 4,532 sa

m

ples (3

4%)

g

NDMA

(2001-2007)

,53 de ec o s o ,53 sa p es (3 %)

• 24 detections of 101 systems (24%) • All detections (Min detect = 1 ng/L) > HRL (0.7 ng

NDEA • 1 detection (30 ng/L) in 106 samples of 14 system

(2001-2007) • Detection > HRL (0.2 ng/L)

NPYR 

(2006-2007)

• No detections in 57 samples of 4 systems• Min detect = N/A

NDPA 

(1995-2007)*

• No detections in 439 samples of 55 systems• Min detect = N/A

* No detection of NDPA in one sample of one system in State of Illinois in 2005 (min de

June 16, 2011 U.S. Environmental Protection Agency 
Key Observations from UCMR2 D

(based on March 2011 version(based on March, 2011 version

• NDMA:

– The predominant nitrosamine in DW (~26% of systems)– Detected ~3x more frequently in SW than GW 

• 4.3% vs 1.4% in chlorinating SW vs GW systems• 11 % 38 6% i hl i i SW GW 11.7

% vs 38.6% in chloraminating SW vs GW systems

– Detected ~10x more frequently in SW PWSs using chloramine

alone

– Generally has higher detection rates and concentrations at ma

Generally has higher detection rates and concentrations at ma

time location in distribution systems than at entry point 

• Essentially no nitrosamine detections in GW systems withou

June 16, 2011 U.S. Environmental Protection Agency 
Nitrosamines: Occurrence (con

Co-Occurrence of Nitrosamines with NDMA in 

Nitrosamine Compounds

#Samples 

with

#Samples 

with NDMA

#Systems 

with

#S

Compounds with wi

Detection

with NDMA

Detection 

also

with

Detection

wi

D

NDE

A 46 8 ( %) 17 26 7 

NPYR 41 19 (46%) 21 8 NDBA 9 2 (22%) 5 

NMEA

3 3 (100%)

3 3 

NMEA

3

3 (100%)

3

3 

June 16, 2011 U.S. Environmental Protection Agency
Drinking Water Strategy 

Grou

p Consideration for Nitrosam

Four 

DWS

• All are carcinogens so likely MCLG could be set at zero• Can measure most using common analytical methods

p

Factors • Most have common treatment/control processes • Have some co-occurrence of NDMA with other nitrosamines

Publi

c

• ~100M people served by systems with at least single detec

ub c

o

n

e

of th

e nitrosamines

Health 

Benefit

o e o t e t osa es

• ~10M people served by systems that have co-occurring nitr

potential for greater public health risk due to additivity of ca

• Controlling nitrosamines reduces exposure to other DBPs

• Exposure from food may be > drinking water for some age 

Issues

Exposure from food may be

> drinking water for some age 

• Regulating nitrosamines could constrain chloramine use an

more costly for some systems to comply with prior disinfectrules

35June 16, 2011 U.S. Environmental Protection Agency 
Chlorate: Background

• ClO

3

- (+5 oxidation state of chlorine atom

• Chlorate salts are used in pesticides 

– Approximately 2.8 million lbs of sodium chlo

applied annually (OPP’s 2006 RED)

• Chl t f d i d i ki t Chlora

te can 

form 

during 

d

rinking wa

ter 

treatment

– During liquid hypochlorite storage During liquid hypochlorite storage

– Disinfection with chlorine dioxide

June 16, 2011 U.S. Environmental Protection Agency 
Chlorate: Health Effects

• 2006 OPP Risk Assessment• Critical Effect: Thyroid gland follicular cell hypertrophy and 

mineralization 

– Based on a BMDL of 0.9 mg/kg/day for thyroid hypertrophy in 

(NTP, 2004)

– RfD = 0.03 mg/kg/day UF=30

• Not likely to cause cancer at doses below those that alter t

hormone homeostasis (OPP, 2006)

• CCL3 HRL: 210 

μg/L (non-cancer)

• Sensitive populations: those at risk for hemolytic anemia a

individuals with compromised renal function

June 16, 2011 U.S. Environmental Protection Agency 
Chlorate: Occurrence

DBP ICR, Jul

y 1997-Dec 1998 

( 

min detect = 20 

Monitoring 

Location

Plants with 

Hypochlorite 

or chlorine

#Samples #samples

≥ 210 μg/L

#Plants w 

Samples

or chlorine

dioxide*

Plant Influent 

(Source Water)

749 4 (0.5%) 106 

Finished Water

Hypochlorite 298 42 (14%) 59 

Chlorine 

Dioxide

384 88 (23%) 29 

* Based on the disinfectant type info. in Table of TUXUNPRO. Only included those plant months 

with a dose of hypochlorite or chlorine dioxide > 0.

• State of California 2001-2007 (min detect = 0.01 μg/L)

June 16, 2011 U.S. Environmental Protection Agency – Detection > HRL (210 μg/L) in 10 of 45 systems (22.2%)
Chlorate: Occurrence (cont.)

Key Observations from ICR Data:• Few detections in source water with levels > HRL• Occurs frequently at levels > HRL in finished water Occurs frequently at levels

> HRL in finished water

• Chlorine dioxide-treated water has more chlorate occurr

than hypochlorite-treated water

• Chlorate levels are not highly variable throughout distrib

Chlorate levels are not highly variable throughout distrib

system when chlorine dioxide is used

EPA i

s e e g ece t su eys ( , r

evi

ewin

g rece

n

t surveys

(AWWA, EP

A

-

C SS) t a

WSS)

t

ha

substantial increases in the number of systems using dipractices associated with high levels of chlorate formati

* P d f UCMR 3 i i *

Propose

d

for UCMR

3 monitoring

June 16, 2011 U.S. Environmental Protection Agency 
Questions, Comments or Any Ot

Nit i

Information to Share?

• Nitrosamines

- N-nitrosodimethylamine (NDMA) - N-nitrosodiethylamine (NDEA) -

N

-nitrosodi nitrosodi

-

n

-propylamine (NDPA) propylamine (NDPA)

- N-nitrosopyrrolidine (NPYR) - N-nitrosodiphenylamine (NDPhA)

• Chlorate

June 16, 2011 U.S. Environmental Protection Agency 
Contaminants Being Considered 

Evaluated for Regulatory Determina

M li Si i USEPA

• Molybdenum

M

elissa Si

mic, USEPA

Molybdenum

• Strontium• Vanadium

June 16, 2011 U.S. Environmental Protection Agency 
Molybdenum Background

• Various molybdenum compounds used in fertilizer alloys p

Various molybdenum compounds used in fertilizer, alloys, p

lubricants, fire retardants, catalysts, and other applications

• Naturally occurring element

• 37 molybdenum-containing compounds reported as produc

in 2006 (CUS)

– Com

pp p g q 

ounds 

produced/im

ported in 

greatest 

quantities were m

and molybdenum trioxide (>1 billion lbs each)

• Industrial releases to surface water (TRI): 

– 45,828 lbs as mol

ybdenum trioxide in 2008

– Up from a low of 23,067 lbs in 2002

• Total industrial releases: ~1.5 million lbs in 2008 (TRI)• Persistent in the environment though form may change Persistent in the environment, though form may change

June 16, 2011 U.S. Environmental Protection Agency 
Molybdenum: Health Effects 

• 1991 IRIS Risk Assessment 1991 IRIS Risk Assessment• Critical Effect: increased serum uric acid 

– Based on a retros

p p gy y ective e

pidemiology stud

y in hum

estimated LOAEL of 0.14 mg/kg/day (Koval’skiy et al., 

– RfD = 0.005 mg/kg/day; UF = 30

• No IRIS cancer assessment No IRIS cancer assessment

- limited available s

limited available s

do not suggest tumorigenic effects

• Essential dietary nutrient for humans

• CCL3 HRL: 35 μg/L (non-cancer)• Sensitive populations: 

– Adults with a predisposition towards gout

June 16, 2011 U.S. Environmental Protection Agency 
Molybdenum: Occurrence

• NIRS 1984 NIRS, 1984

-1986 (MRL 6 1986 (MRL = 

6

μ

g/L):

– Detections > HRL (35 

μg/L) in 6 of 989 samples/systems (0.6

pop)

• C lif i 1995 C

alifornia , 1995

-2007 ( i d t t 0 005 2007

(

min 

d

e

tec

t = 

0.005

μ

g/L): 

– Detections > HRL in 6 of 161 systems (3.73%)– Detections > HRL in 17 of 2,287 samples (0.74%) 

• Illinois, 1998-2005 (min detect = 2.5 

μg/L): 

– Detections > HRL in 29 of 865 systems (3.4%)– Detections > HRL in 54 of 2k samples (2.8%) 

• Ohio, 1999-2005 (min detect = 1 

μg/L): 

– Detections > HRL (35 

μg/L) in 2 of 26 systems (8%)

– Detections > HRL in 4 of 76 samples (5%) 

June 16, 2011 U.S. Environmental Protection Agency 
Molybdenum: Occurrence

• Wisconsin 2001 (min detect = N/A): Wisconsin, 2001 (min detect

= N/A):

– No detections in 2 samples at 1 system

• USGS (Toccalino et al., 2010) (MRL = 0.06-1 

μg/L)

– D t ti HRL i 4 f 628 l / t (0 64%) D

e

tections > HRL in 

4 o

f 628 samples

/sys

tems (0.64%)

* Proposed for UCMR 3 monitoring

June 16, 2011 U.S. Environmental Protection Agency 
Strontium: Background

• Used in fertilizers, p

y y rotechnics, previousl

y used in cath

tube TVs; present in coal

• Mining in U.S. ceased in 1959. Annual imports of stron

minerals and com

p y ounds have steadil

y declined since 2

than 10,000 metric tons

• Naturally occurs and enters water through weathering o

soils, p p, 

 from atmos

pheric de

position, and from wastewate

• 11 strontium-containing compounds reported as produc

in 2006 (CUS) 

– Strontium carbonate reported as produced/imported in the g

Strontium carbonate reported as produced/imported in the g

quantity (10 million - <50 million lbs)

• Industrial releases: no TRI data • Expected to have moderate to low mobility in soils (ATS

have moderate to low mobility in soils (ATS

June 16, 2011 U.S. Environmental Protection Agency 
Strontium: Health Effects 

• 1992 IRIS Risk Assessment• Critical Effect = structural changes in growing bo

impaired calcification

– Based on a 20-day oral study in young & adult rats; NO

mg/kg/day (Storey, 1961)

– RfD = 0.6 mg/kg/day; UF = 300

• No IRIS cancer assessment - limited available s

do not indicate tumorigenic effects

• CCL3 HRL: 4 200 μg/L (non CCL3 HRL:

4,200 μg/L (non

-cancer) cancer)

• Sensitive populations: 

– Infants, , gp 

 children, and adolescents durin

g the 

period of 

June 16, 2011 U.S. Environmental Protection Agency 
Strontium: Occurrence

• NIRS, 1984-1986 (MRL = 1 

μg/L):

– Detections > HRL (4,200 

μg/L) in 23 of 989 samples/syste

1.7M pop)

• Illinois, 1998-2005 (min detect = 71 

μg/L): 

– Detections > HRL in 4 of 19 systems (21%)– Detections > HRL in 4 of 21 samples (19%)

• Ohio, 2000-2005 (min detect = 4 

μg/L): 

– Detections > HRL in 6 of 32 systems (19%)– Detections > HRL in 17 of 77 samples (22%)

• Region 9 Tribes, 2003 (min detect = N/A):

– No detections in 1 sample/system

• USGS (Toccalino et al., 2010) (min detect = 5.61 

μg/L)

– Detections > HRL in 40 of 503 sam

p y () les/s

ystems (8%)

* Proposed for UCMR 3 monitoringJune 16, 2011 U.S. Environmental Protection Agency 
Vanadium: Background

• Extracted from ores and recovered from petroleum and industria• Used primarily (92%) for metallurgical applications; also used in 

lamps, paints and varnishes, flue-gas scrubbers, and photograp

• 11 vanadium compounds reported as produced/imported in 200

11 vanadium compounds reported as produced/imported in 200

– Those produced/imported in greatest quantities were vanadium pentoxid

hydroxide oxide phosphate (both in range of 1-10 million lbs)

• Industrial releases to surface water in 2008 ( ) TRI : 

– 7,790 lbs of vanadium (except alloys); up from a low of 616 lbs in 1998– 1.2 million lbs of vanadium compounds; up from low of 0.4 million lbs in 

• Total industrial releases in 2008 (TRI): Total industrial releases in 2008 (TRI):

– 2.3 million lbs of vanadium (except alloys); 42.8 million lbs of V compou

• Also released to the environment through the weathering of rock• Vanadium is more mobile in neutral and alkaline soils than in ac

Vanadium is more mobile in neutral and alkaline soils than in ac

June 16, 2011 U.S. Environmental Protection Agency 
Vanadium: Health Effects 

• 1992 ATSDR Risk Assessment• Critical effect = minor renal effects, increased plasma ure

structural tissue changes 

– Based on an oral study in rats; NOAEL = 0.3 mg/kg/day (D

1985)

– MRL* = 0.003 mg/kg/day; UF = 100 

• Vanadium pentoxide is associated with pulmonary tumor

(2002) inhalation study; clear evidence in mice and some male rats. (IRIS assessment in process) 

• CCL 3 HRL = 21 μg/L (non-cancer)• Sensitive populations: individuals with compromised rena

* MRL for ATSDR = Minimum Risk Level

June 16, 2011 U.S. Environmental Protection Agency 
Vanadium: Occurrence

• NIRS, 1984 NIRS, 1984

-1986 (MRL 1986 (MRL

=

3

μg/L):

– Detections > HRL (21 

μg/L) in 17 of 989 samples/systems (1

pop)

• California, 1996 California, 1996

-2007 (min detect 2007 (min detect

= 0.002

μg/L):

– Detections > HRL in 483 of 2,698 systems (18%)– Detections > HRL in 2,604 of 26k samples (10%)

• Illinois 1998 Illinois, 1998

-2004 (min detect 2004 (min detect

= N/A):

– No detections in 19 samples at 17 systems

• Ohio, 1999-2005 (min detect = N/A): 

– No detections in 71 samples at 23 systems No detections in 71 samples at 23 systems

• USGS (Toccalino et al., 2010) (MRL = 0.02- 5 

μg/L):

– Detections > HRL in 49 of 457 samples/systems (11%)

* P d f UCMR 3 it i *

Propose

d

for UCMR

3 monitoring

June 16, 2011 U.S. Environmental Protection Agency 
Questions, Comments or Any Ot

Information to Share?

• Molybdenum• Strontium• V di ana um

June 16, 2011 U.S. Environmental Protection Agency 
Contaminants Being Considered 

Evaluated for Regulatory DeterminaEvaluated for Regulatory Determina

Zeno Bain, USEPA

• 1,1,1,2-Tetrachloroethane• 123

-Trichloropropane (TCP)

Zeno Bain, USEPA

1,2,3 Trichloropropane (TCP)

• 1,3-Dinitrobenzene• 1,4-Dioxane• Meth

y yy ( ) l Tertiar

y But

yl Ether 

(MTBE

)

• Nitrobenzene• PFOS and PFOA• RDX

June 16, 2011 U.S. Environmental Protection Agency 
1,1,1,2-Tetrachloroethane: Backgro

• An industrial chemical used in the production of other subst• No natural sources• Production: 1 million Production:

1 million

- 10 million lbs in 2002 (CUS) 10 million lbs in 2002 (CUS)

– Up from 10,000 - 500,000 lbs in 1994

• Industrial releases to surface water: 0 lbs in 2008 (TRI)

– Do n from high of 474 lbs in 2003 Do

w

n from high of 474 lbs in 2003

• Total industrial releases: 2,904 lbs in 2008 (TRI)• Some physical and chemical properties indicate not very m

wat b t th ti di t d t t hi h bilit ter 

b

u

t other properties predi

c

t mo

dera

te 

to hi

g

h mobilit

y

– Projected half-life in water is 60 days (PBT Profiler)– Persistent in the environment (biodegrades sometimes/recalc

June 16, 2011 U.S. Environmental Protection Agency 
1,1,1,2-Tetrachloroethane: Health Ef

• 1987/9 IRIS Risk Assessment• Critical Effect = Cancer; Hepatocellular adenomas & carcin

– Based on 2 

y gg ( ) 

ear chronic oral 

gava

ge NTP (1983) mice bioas

– Cancer slope factor = (0.026 mg/kg-day)- 1 – Possible human carcinogen (1986) 

• Non

-cancer effect = Histological changes in kidneys & live

cancer effect

= Histological changes in kidneys

& live

– Based on chronic oral gavage rat study NTP (1983) – RfD = 0.03 mg/kg-day; LOAEL = 89.3 mg/kg-day; UF = 3,000

• CCL3 HRL: 1 μg/L (cancer); 210 μg/L (non CCL3 HRL:

1 μg/L (cancer); 210 μg/L (non

-cancer) cancer)

• Sensitive populations: None

June 16, 2011 U.S. Environmental Protection Agency 
1,1,1,2-Tetrachloroethane: Occurre

• UCM Round 1, 1988-1992 (min detect = 0.06 

μg/L):

– Detections > HRL (1 

μg/L) in 9 of 17k systems (0.05%; 250k 

– Detections > HRL in 11 of 57k samples (0.02%) 

• UCM Round 2, 1993-1997 (min detect = 0.2 

μg/L):

– Detections > HRL in 8 of 24k systems (0.03%; 125k pop.) – Detections > HRL in 11 of 98k samples (0.01%) 

• California, 1995-2007 

(min detect = 0.5 

μg ) /L

): 

– Detections > 1⁄2 HRL in 4 of 4k systems (0.1%)– Detections > 1⁄2 HRL in 6 of 116k samples (0.01%)

• Florida, 2004-2007 

(min detect = 0.09 

μ

g ) /L

):

– Detections in 1 of 27 systems (4%)– Detections in 2 of 1,764 samples (0.1%)

• Illinois 1998 Illinois, 1998

-1999 (min detect 1999 (min detect

= N/A):

– No detections of 7 samples in 2 systems

June 16, 2011 U.S. Environmental Protection Agency 
1,1,1,2-Tetrachloroethane: Occurre

• N th C li 1998 North

Carolina, 1998

-2005 ( i d t t 0 5 2005

(

min 

d

e

tec

t = 

0.5

μ

g/L): 

– Detections > HRL (1 

μg/L) in 5 of 2,500 systems (0.2%) 

– Detections > HRL in 5 of 20k samples (0.03%)

• Ohio, 1998-2005 (min detect = 0.8 

μg/L): 

– Detections > 1⁄2 HRL (0.5 

μg/L) in 1 of 2,500 systems (0.04%

– Detections > 1⁄2 HRL in 1 of 9k samples (0.01%)

• Region 9 Tribes, 1998-2005 (min detect = N/A): 

– No detections of 1k samples in 285 systems

• South Dakota, 1990-2007 

( ) min detect = N/A

): 

– No detections of 1k samples in 281 systems

• Texas, 1998-2005 (min detect = N/A): 

– No detections of 36k samples in 6k systems No detections of 36k samples in 6k systems

June 16, 2011 U.S. Environmental Protection Agency 
1,1,1,2-Tetrachloroethane: Occurr

• Wisconsin, 1983-2009 (min detect = N/A): 

– No detections of 21k samples in 3k systems

• USGS data, 1993-2007 (Toccalino et al., 2010) (M

μg/L): 

– No detections > 1⁄2 the HRL (0 5 No detections

>

1⁄2 the HRL (0.5

μg/L) in 832 samples/s

g/L) in 832 samples/s

– 3 detects total, all between 0.009 and 0.011 

μg/L 

• USGS data, 2002-2005 (Hopple et al., 2009 and 

et l 2008) ( i d t t N/A) t al., 2008)

(

min 

d

e

tec

t = N/A)

– Phase 1: No detections of 368 samples– Phase 2: No detections in 142 sam

ples

June 16, 2011 U.S. Environmental Protection Agency 
1,2,3-Trichloropropane: Backgrou

• Used as a chemical intermediate and as a paint and var

remover, solvent, and degreasing agent

• No natural sources• Production: 0.5 million - 1 million lbs in 2002 (CUS)

– Down from 10–50M lbs in 1986

• Industrial releases to surface water: 187 lbs in 2008 (TR

Industrial releases to surface water: 187 lbs in 2008 (TR

– Down from 5,498 lbs in 2000 but up from 62 lbs reported i

• Total industrial releases: 1,557 lbs in 2008 (TRI)• Some physical and chemical properties indicate mobility 

Some physical and chemical properties indicate mobility 

volatility in water and soil

– Projected half-life in water is 38 days (PBT Profiler)– Persistent in the environment (biodegrades slowly with ac

Persistent in the environment (biodegrades slowly with ac

June 16, 2011 U.S. Environmental Protection Agency 
1,2,3-Trichloropropane: Health Eff

• RAISHE Risk Assessment (2007)• Critical Effect = Cancer; multisite tumors in mice and rats 

Cancer Slope factor = 7 (mg/kg/day)-1 – Cancer Slope factor

=

7 (mg/kg/day)

* -1

• Non-cancer effect = liver and kidney damage; decreased 

cells

– 120

-d t d i t (NTP 1983) day gavage s

t

u

dy in ra

ts (NTP, 1983)

– RfD = 0.006 mg/kg/day; UF = 1000

• CCL3 HRL: 0.005 μg/L (cancer); 42 μg/L (non-cancer)• Sensitive populations = pregnant women, individuals with 

kidney problems

*The RAISHE slope factor used for CCL3 was removed from the database

June 16, 2011 U.S. Environmental Protection Agency 

The RAISHE slope factor used for CCL3 was removed from the database

when the EPA IRIS (2009) assessment was completed. 
1,2,3-Trichloropropane: Occurren

• UCM Round 1, 1988-1992 (min detect = 0.1 

μg/L):

– Detections > HRL (0.005 

μg/L) in 44 of 17k systems (0.3%; 1

– Detections > HRL in 76 of 57k samples (0.1%) 

• UCM Round 2, 1993-1997 (min detect = 0.3 

μg/L):

– Detections > HRL in 19 of 24k systems (0.1%; 0.13M pop.) – Detections > HRL in 23 of 98k sam

p( ) les (0.02%)

• California, 1995-2007 (min detect = 0.001 

μg/L)

– Detections in 157 of 4k systems (4%) – Detections in 5k of 113k samples (4%) Detections in 5k of 113k samples (4%)

• Florida, 2004-2007 (min detect = 1.9 

μg/L)

– Detections in 1 of 27 systems (4%) – Detections in 1 of 1 766 samples (0 1%) Detections in

1 of

1,766 samples (0.1%)

June 16, 2011 U.S. Environmental Protection Agency 
1,2,3-Trichloropropane: Occurren

• Illinois 1998 Illinois, 1998

-2004 (min detect = 250 2004 (min detect

= 250

μg/L)

– Detections in 4 of 6 systems (70%) – Detections in 4 of 11 samples (40%) 

• North Carolina 1998 North Carolina, 1998

-2005 (min detect 0 57 2005 (min detect = 

0.57

μg/L)

– Detections in 5 of 2,493 systems (0.2%) – Detections in 18 of 20k samples (0.09%) 

• Ohi 1998 Ohio, 1998

-2005 ( i d t t 0 5 2005

(

min 

d

e

tec

t = 

0.5

μ

g/L)

– Detections in 1 of 2,532 systems (0.04%) – Detections in 1 of 9,283 samples (0.01%) 

• Region 9 Tribes, 1998-2005 (min detect = 1.8 

μg/L)

– Detections in 2 of 279 systems (0.7%) – Detections in 3 of 1,113 samples (0.3%) 

June 16, 2011 U.S. Environmental Protection Agency 
1,2,3-Trichloropropane: Occurren

• S th D k t 1990 South

D

a

k

o

ta, 1990

-2007 ( i d t t 0 67 2007

(

min 

d

e

tec

t = 

0.67

μ

g/L)

– Detections in 1 of 281 systems (0.4%) – Detections in 1 of 1k samples (0.1%) 

• Texas, 1998-2005 (min detect = 13 

μg/L)

– Detections in 5 of 5,660 systems (0.1%) – Detections in 7 of 36k samples (0.02%) 

• Wisconsin, 1983-2009 (min detect = 0.1 

μg/L)

– Detections in 12 of 3k systems (0.4%) – Detections in 12 of 20k samples (0.06%)

* Proposed for UCMR 3 monitoringJune 16, 2011 U.S. Environmental Protection Agency 
1,3-Dinitrobenzene: Backgroun

• Used as an industrial chemical and in the production of ot

Used as an industrial chemical and in the production of ot

substances

• No natural sources

• P d ti 10 Pro

duction: 10 - 50 illi lb i 1986 (CUS) 50 million lbs in 1986 (CUS)

– Data not reported for any other years

• Industrial releases to surface water: 2 lbs in 2008 (TRI)

– Down from high of 816 lbs in 1997

• Totals industrial releases: 19,858 lbs in 2008 (TRI)• Expected to be moderately to highly mobile in water, base

physical and chemical properties 

– Projected half-life in water is 38 days (PBT Profiler)– Moderately persistent in the environment (biodegrades slow

acclimation) 

June 16, 2011 U.S. Environmental Protection Agency 
1,3-Dinitrobenzene: Health Effec

• 1988 IRIS Risk Assessment 1988 IRIS Risk Assessment

• Critical Effect = Increased spleen weight

– Based on sub-chronic drinkin

g y (

 water stud

y in rats 

(198

– Chronic oral RfD = 0.0001 mg/kg/day; NOAEL = 0.4 m

UF = 3,000

• Not classifiable as to human carcinogenicity (198

Not classifiable as to human carcinogenicity (198

• CCL3 HRL: 0.7 μg/L (non-cancer)• Sensitive 

p po

pulations: 

– Individuals with a genetic predisposition to methemoglo

and/or hemosiderosis

– Males having other sperm production complications co

Males having other sperm production complications co

have increased sensitivity

June 16, 2011 U.S. Environmental Protection Agency 
1,3-Dinitrobenzene: Occurrenc

• UCMR 2 Assessment Monitoring, 2008-2010 (M

μg/L) 

– No detections of 31 710 samples in 4 115 systems No detections of 31,710 samples in

4,115 systems

– HRL (0.7 

μg/L) is less than MRL

– Sampling not yet complete (data current as of March 1

June 16, 2011 U.S. Environmental Protection Agency 
1,4-Dioxane: Background

• Solvent or solvent stabilizer in the manufacture/processing 

Solvent or solvent stabilizer in the manufacture/processing 

cotton, textile products, automotive coolant, cosmetics, and 

• No natural sources

• P d ti 1 Pro

duction: 

1

– 10 illi lb i 2006 (CUS) 10 million lbs in 2006 (CUS)

– Down from 10 – 50 million lbs in 1986

• Industrial releases to surface water: 41,014 lbs in 2008 (TR

– Down from high of 196,375 lbs in 1997

• Total industrial releases: 203,798 lbs in 2008 (TRI)• Expected to be moderately to highly mobile in water based 

and chemical properties

– Projected half-life in water is 15 days (PBT Profiler)– Moderately persistent in the environment (biodegrades slowly

June 16, 2011 U.S. Environmental Protection Agency 
1,4-Dioxane: Health Effects

• 1988 IRIS Ri k A t 1988 IRIS Ri

s

k

Assessmen

t

• Critical Effect = Cancer; Nasal cavity and liver carcinomas 

– Based on 2 year drinking water study in male rats– Cancer Slope Factor = (0.011 mg/kg-day)-1

• Non-cancer effect = Liver and kidney toxicity

– Based on 2 yr chronic drinking water study in male rats (1974– *MRL = 0.1 mg/kg-day, NOAEL = 9.6 mg/kg-day, UF = 100

• CCL3 HRL 3 

μg/L (cancer); 700

μg/L (non-cancer)

• Sensitive populations: Children may be more sensitive to liv

Sensitive populations: Children may be more sensitive to liv

*ATSDR Minimum Risk Level

June 16, 2011 U.S. Environmental Protection Agency 
1,4-Dioxane: Occurrence

• California, 1996-2007 (min detect = 0.001 μg/L

– Detections > HRL (3 μg/L) in 13 of 218 systems (6%) – Detections > HRL in 199 of 4 245 samples (5%) Detections

> HRL in 199 of

4,245 samples (5%)

* Pro

p g osed for UCMR 3 monitorin

g

June 16, 2011 U.S. Environmental Protection Agency 
Methyl Tertiary Butyl Ether (MTBE): Bac

• U d li dditi d i th f t f i 

Use

d as a gasoline additive an

d in the manu

fac

ture o

f iso

an extraction solvent

• No natural sources

• Production: > 1 billion lbs in 2006 (CUS)

– Down from ~80 million barrels (1999) to <24 million barrels 

(USDOE)

• Industrial releases to surface water: 1,832 lbs in 2008 (TR

– Down from 162,116 lbs in 1997

• Total industrial releases: 351,774 lbs in 2008 (TRI)• Expected to be moderately to highly mobile in water, base

physical and chemical properties

– Projected half-life in water is 15 da

y( ) sPBT Profiler)

– Moderately persistent in the environment (biodegrades slow

June 16, 2011 U.S. Environmental Protection Agency 
MTBE: Health Effects

• 1999 OEHHA(CA) risk assessment (IRIS assessment in p• Critical Effect = Cancer; kidney adenomas/carcinomas & 

tumors in male rats, leukemia & lymphomas in female rats

– Based on a chronic drinking water study in rats– Cancer slope factor = (0.0018 mg/kg-day)-1

• Non-cancer effect = Decreased blood urea nitrogen levels 

– Based on 90 day gavage study in rats – *MRL = 0.3 mg/kg-day; LOAEL = 100 mg/kg-day

• CCL3 HRL: 19.4 

μg/L (cancer); 2100 

μg/L (non-cancer)

• Sensitive population: None Sensitive population: None

• 1997 Drinking Water Advisory

– Recommends 20-40 ppb based on taste and odor which als

protections from adverse health effects with a margin of safeprotections from adverse health effects with

a margin of safe

*ATSDR Minimum Risk Level

June 16, 2011 U.S. Environmental Protection Agency 
MTBE: Occurrence

• UCMR 1 A t M it i (MRL 5 UCMR

1

Assessmen

t

Monitoring (MRL = 

5

μ

g/L):

– Detections > HRL (19.4 μg/L) in 5 of 4k systems (0.13%; 213– Detections > HRL in 5 of 34k samples (0.015%)

• California, 1995-2007 (min detect = 0.2 

μg/L): 

– Detections > HRL in 19 of 4k systems (0.4%) – Detections > HRL in 542 of 134k samples (0.4%)

• Florida, 2004-2007 (min detect = 0.1 

μg/L): 

– Detections > HRL in 1 of 31 systems (3%) – Detections > HRL in 26 of 2k samples (1%)

• Illinois, 1998-2005 (min detect = 0.5 

μg/L): 

– Detections > 1⁄2 HRL (9.7 μg/L) in 2 of 1k systems (0.2%) – Detections > 1⁄2 HRL in 12 of 7k sam

p( ) les (0.2%)

June 16, 2011 U.S. Environmental Protection Agency 
MTBE: Occurrence

• Ohio, 1999-2005 (min detect = 0.5 

μg/L): 

– Detections in 6 of 1k systems (0.5%); None > 1⁄2 HRL (9.7 μg– Detections in 57 of 4k samples (1.5%); None > 1⁄2 HRL

• Region 9 Tribes, 1998-2005 (min detect = 9.8 

μg/L): 

– Detections > 1⁄2 HRL in 1 of 219 systems (0.5%)– Detection > 1⁄2 HRL in 1 of 764 samples (0.1%)

• Texas, 1998-2005 

(min detect = 0.5 

μg ) /L

): 

– Detections > HRL in 3 of 6k systems (0.05%)– Detection > HRL in 4 of 36k samples (0.01%)

• Wisconsin, 1991-2009 

(min detect = 0.1 

μg ) /L

): 

– Detections > HRL in 4 of 1k systems (0.4%)– Detection > HRL in 22 of 4k samples (0.5%)

• USGS (Toccalino et al 2010) (MRL USGS (Toccalino et al., 2010) (MRL

= 0 05 . -0 2. μg/L):

– No detections > HRL in 832 systems/samples

June 16, 2011 U.S. Environmental Protection Agency 
Nitrobenzene: Background 

• U d i th d ti f ili d f i t l t li 

Use

d in the pro

duction o

f aniline an

d

for pain

t solven

t, poli

explosives, pesticides, and drugs

• No significant natural sources

• Production: >1 billion lbs in 2006 (CUS)

– Reported at this level since 1990– >500 million – 1 billion in 1986

• Industrial releases to surface water: 189 lbs in 2008 (TRI)

– Down from a high of 1,152 lbs in 1998, but up from a low of 2

• Total industrial releases: 487, () 627 lbs 

(TRI

)

• Expected to be moderately to highly mobile in water, base

physical and chemical properties

– Projected half-life in water is 15 da

y( ) sPBT Profiler)

– Not persistent in the environment (biodegrades fast with acclimation

June 16, 2011 U.S. Environmental Protection Agency 
Nitrobenzene: Health Effects

• 2009 IRIS Ri k A t 2009 IRIS Ri

s

k

Assessmen

t

• Critical Effect = Increased immature red blood cells & 

methemoglobinemia

– Based on subchronic rat study (NTP, 1983)– RfD = 0.002 mg/kg-day; BMDL10 = 1.8 mg/kg-day; UF = 1,00

• Likely a carcinogen (2005) for all exposure routes

– No slope factor for the oral route

• CCL3 HRL: 14 μg/L (non-cancer)• Sensitive 

p po

pulations: 

– Neonates– Persons prone to hereditary methemoglobinemia– Persons with decreased 

glucose-6-

p p yg 

hos

phate deh

ydro

genas

June 16, 2011 U.S. Environmental Protection Agency 
Nitrobenzene: Occurrence

• UCMR 1 Assessment Monitoring, 2001-2003 (MRL = 10 

– Detections > HRL (14 

μg/L) in 2 of 4k systems (0.05%; 26

– Detections > HRL in 2 of 33k samples (0 01%) Detections

> HRL in

2 of 33k samples (0.01%)

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

μg/L

– No detections in 2k samples of 295 systems

• C lif i 1995 C

alifornia, 1995

-2007 ( i d t t 5 2007

(

min 

d

e

tec

t = 

5

μ

g/L): 

– No detections > HRL in 11k samples of 546 systems 

• Illinois, 1999-2005 (min detect = N/A): 

– No detections in 336 samples of 85 systems 

• Ohio, 2000-2005 (min detect = N/A): 

– No detections in 3k samples of 1,134 systems 

June 16, 2011 U.S. Environmental Protection Agency 
PFOS/PFOA: Background

• Used in industrial and consumer products mainly to repel 

Used in industrial and consumer products mainly to repel 

and soil; photographic film; fire-fighting foams; floor polishacid for circuit boards; in pesticides; home furnishings and 

masking tape masking tape

• No natural sources• Production: 10K-500K lbs for PFOS and PFOA in 2002 (C

– <500 000 lbs for PFOA in 2006 (PFOS not reported in 2006) <500,000 lbs for PFOA in 2006 (PFOS not reported in 2006)

• Industrial releases: no data (TRI)• Physical /chemical properties indicate not very mobile to v

– Projected biodegradation half-life for PFOA in water is 180 d

Profiler)

– Both are persistent in the environment (biodegrades 

sometimes/recalcitrant)

June 16, 2011 U.S. Environmental Protection Agency 
PFOS/PFOA: Health Effects

• PFOS: Critical Effect = Increases in thyroid PFOS: Critical Effect

= Increases in thyroid

-related hormo

related hormo

high density lipoproteins in monkeys (Seacat et al., 2002)

– Based on a NOAEL of 0.03 mg/kg-day– RfD

-eq = 0 00003 mg/kg/day UF =default 1000 eq

=

0.00003 mg/kg/day UF =default 1000

– CCL3 HRL = 0.2 

μg/L (non-cancer)

• PFOA: Critical Effect = Increase in maternal liver weight o

mice at term (Lau et al 2006) mice at term (Lau et al., 2006)

– Based on a BMDL10 = 0.46 mg/kg-day

– RfD-eq = 0.00015 mg/kg/day UF= default 3000

– CCL3 HRL = 1 1 CCL3 HRL

=

1.1

μg/L (non g/L (non

-cancer) cancer)

• Suggestive evidence for cancer for both however some da

support non-linear modes of action; assessments not com

• S iti l ti t t l t l h t i d Sensitive populations: no

t ye

t comple

t

ely c

harac

terize

d

June 16, 2011 U.S. Environmental Protection Agency 
PFOS/PFOA: Occurrence

• T Ri i Al b 2000 Tennessee River in Al

a

bama, 2000: 

– PFOS: Detected in all 40 samples; Max (0.144 

μg/L) > 1⁄2 HR

μg/L); Min detect = 0.0168 

μg/L 

– PFOA D t t d i 18 (45%) f 40 l M (0 598 PFOA: D

e

tec

t

e

d in 18 (45%) o

f 40 samples; 

Max (0.598

μ

g/

/

(0.55 

μg/L); Min detect = 0.025 

μg/L

• Lake Erie and Lake Ontario, 2003: 

– PFOS: Detected in all 16 samples; Max (0 121 PFOS: Detected in all 16 samples; Max (0.121

μg/L) > 1⁄2 HR

g/L)

>

1⁄2 HR

μg/L); Min detect = 0.011 

μg/L

– PFOA: Detected in all 16 samples; Max (0.070 

μg/L) < 1⁄2 HR

μg/L); Min detect g/L); Min detect

= 0.015

μg/L

June 16, 2011 U.S. Environmental Protection Agency 
PFOS/PFOA: Occurrence

• Mi t ( bli d i t ll ) 2004 Minneso

ta 

(public an

d priva

te well

s

), 2004

-2005: 

– PFOS: Detected in 6 (7%) of 85 wells; Max (1.4 

μg/L) > HRL 

min detect = N/A

– PFOA D t t d i 7 (8%) f 85 ll M (0 9 PFOA: D

e

tec

t

e

d in 

7 (8%) o

f 85 wells; 

Max (0.9

μ

g/L) < 1⁄2 H

/L)

<

1⁄2 H

μg/L); min detect = N/A

• New Jersey, 2006:

– PFOS: Detected and quantitated in 2 (29%) of 7 finished wa

PFOS: Detected and quantitated in

2 (29%) of

7 finished wa

samples/systems; Max (0.014 

μg/L) < 1⁄2 HRL (0.1 

μg/L); Min 

0.004 

μg/L

– PFOA: Detected and quantitated in 4 (57%) of 7 samples/sy

PFOA: Detected and quantitated in

4 (57%) of

7 samples/sy

(0.039 

μg/L) < 1⁄2 HRL (0.55 

μg/L) ; Min detect < 0.004 

μg/L

June 16, 2011 U.S. Environmental Protection Agency 
PFOS/PFOA: Occurrence

• Littl H ki OH 2002 Little 

Hocking, OH, 2002

-2005: 

– PFOS: No data– PFOA in distribution system: average concentrations rangin

7 2. μ

g/L ll > HRL (1 1 /L, all

> HRL (1.1

μ

g/L) d t ti li it 0 01 /L); d

e

tection li

mit = 

0.01

μ

g/L.

– PFOA in local wells: concentrations ranging from <0.01 

μg/L 

• Upper Mississippi River Basin, 2008 (min detect = 0.001 

μ

– PFOS: Detected and quantitated in 123 (71%) of 173 sampl

(0.287 

μg/L) > HRL (0.2 

μg/L); Min detect = 0.001 

μg/L

– PFOA: Detected and quantitated in 126 (73%) of 173 sampl

(0 125 . μg/L) < 1⁄2 HRL (0 55 g/L)

<

1⁄2 HRL (0.55

μg/L); Min detect = 0 001 g/L); Min detect

=

0.001

μg/L

* Proposed for UCMR 3 monitoring

June 16, 2011 U.S. Environmental Protection Agency 
RDX: Background

• Used as an explosive by the U.S. military (super

TNT as the primarily used explosive) and for somcivilian uses civilian uses

• No natural sources• Production: 1 million – <10 million lbs in 2006 (C• Industrial Releases: No data (TRI)

June 16, 2011 U.S. Environmental Protection Agency 
RDX: Health Effects

• 1993 IRIS Risk Assessment 1993 IRIS Risk Assessment• Critical Effect = Cancer; hepatocellular 

carcinomas/adenomas

– Based on 24-month study in mice (1984) – Cancer slope factor = (0.11 mg/kg-day)-1

• Non

-cancer effect = inflammation of the prostate cancer effect

= inflammation of the prostate

– Based on 2-year rat feeding study – RfD = 0.003 mg/kg-day; NOEL = 0.3 mg/kg-day; UF = 

• CCL3 HRL: 0.3 μg/L (cancer); 21 μg/L (non-can• Sensitive populations: None

June 16, 2011 U.S. Environmental Protection Agency 
RDX: Occurrence

• UCMR 2 Assessment Monitoring, 2008-2010 (M

μg/L)

– Detections > HRL (0 3 Detections > HRL (0.3 μg/L ) in 3 of 4 115 systems (0 

g/L ) in 3 of 4,115 systems (0.

pop)

– Sampling not yet complete (data current as of March 1

• California, 2006 (min detect = N/A):

– No detections in 1 sample at 1 system

June 16, 2011 U.S. Environmental Protection Agency 
Questions, Comments or Any Ot

Information to Share? Information to Share?

• 1,1,1,2-Tetrachloroethane• 123 , , -T i hl (TCP) T

richloropropane (TCP)

• 1,3-Dinitrobenzene• 1,4-Dioxane• Methyl Tertiary Butyl Ether (MTBE) • Methyl Tertiary Butyl Ether (MTBE)• Nitrobenzene• PFOS and PFOA• RDX

June 16, 2011 U.S. Environmental Protection Agency 
Contaminants Being Considered 

E l t d f R l t D t i Evalua

t

e

d

for 

Regula

tory 

D

e

termina

G C l USEPA

• Dimethoate

Di lf t

Guy 

C

ole, USEPA

• Disulfo

ton 

• Diuron• Molinate

• Terbufos and Terbufos Sulfone • Terbufos and Terbufos Sulfone

June 16, 2011 U.S. Environmental Protection Agency 
Dimethoate: Background

• Commonly used as an insecticide on field crops (e g 

Commonly used as an insecticide on field crops (e.g.

alfalfa, corn, and cotton), orchard crops, vegetable crforestry, and for residential purposes. 

• Usage estimated at 1 8 million lbs in 2008 (OPP) Usage estimated at 1.8 million lbs in 2008 (OPP)

– Up from 1986: 500,000 – 1 million lbs production/importation 

• Total industrial releases:15,561 lbs in 2008 (TRI)• No natural sources• Fate and Transport

– Physical/chemical properties indicate very mobile in water Physical/chemical properties indicate very mobile in water– 36% partitions to water (modeled system of water, air, soil, a– Moderately persistent (biodegrades slowly with acclimation)

June 16, 2011 U.S. Environmental Protection Agency 
Dimethoate: Health Effects

• 2007 OPP Risk Assessment 2007 OPP Risk Assessment• Critical Effect = Brain cholinesterase inhibition

– 2-

y y ear chronic stud

y in rats

– Chronic oral RfD = 0.0022 mg/kg/day

• Possible human carcinogen ‘C’ (CARC 1991)

– E i l h l h ti l t i l B6C3

Equivocal hemolymp

horeticular 

tumors in male B6C3

and a weak response for combined spleen, skin, and tumors in male Wistar rats.

• CCL3 HRL: 15.4 

μg/L (non-cancer)

• Sensitive populations: None

June 16, 2011 U.S. Environmental Protection Agency 
Dimethoate: Occurrence

• UCMR 2 Assessment Monitoring, 2008-2010 (M

0.7 μg/L)

– No detections in 32k samples of 4,116 systems

– Sampling not yet complete (data current as of March 

• USGS data, 2002 USGS data, 2002

-2005 (Hopple et al., 2009 and 2005 (Hopple et al., 2009 an

Kingsbury et al., 2008) (reporting level = 0.0061 

– Phase 1: No detections in 221 wells; 2 (1.4%) detectio

SW samples in 9 systems (max estimated at 0 009 SW samples in

9 systems (max estimated at

0.009

μg

g

detections > 1⁄2 HRL

– Phase 2: No detections in 48 raw & finished GW sam

June 16, 2011 U.S. Environmental Protection Agency 
D is u lfo to n : B a c k g r o u n d

• Used as organophosphate pesticide/insecticide on cotton 

Used as organophosphate pesticide/insecticide on cotton

sugar beets, asparagus, corn, peanuts, wheat, ornamentgrains including barley for malting, and potatoes

• Usage:

– 1.2 million lbs applied annually between 1987-1998 (OPP 2– ~1.8 million lbs applied on 24 crops in 34 states in 1992 and 

lbs on 23 crops in 32 states in 1997 (NCFAP) lbs on 23 crops in 32 states in 1997 (NCFAP)

• Industrial releases: no TRI data• No natural sources• Expected to be not very mobile to moderately mobile in w

Expected to be not very mobile to moderately mobile in w

based on physical and chemical properties

• Moderately persistent in the environment (biodegrades s

June 16, 2011 U.S. Environmental Protection Agency 
Disulfoton: USGS Usage Map (ca. 

June 16, 2011 U.S. Environmental Protection Agency 
Disulfoton: Health Effects

• 2002 OPP Risk Assessment• Critical Effect = Plasma, RBC, brain & co

cholinesterase inhibition 

– Based on 1 year toxicity dog study– RfD = 0.00013 mg/kg-day; NOAEL = 0.013 mg/kg

UF = 100

• CCL3 HRL: 0 91 CCL3 HRL:

0.91

μg/L (non g/L (non

-cancer) cancer)

• Sensitive populations: None

June 16, 2011 U.S. Environmental Protection Agency 
Disulfoton: Occurrence

• UCMR 1 S i S 2001 UCMR

1

Screening 

Survey, 2001

-2003 (MRL 0 5 2003 (MRL = 

0.5

μ

– No detections of 2k samples in 295 systems

• California, 1995-2007 

( ) min detect = N/A

): 

– No detections reported

• Illinois, 2001 (min detect = N/A): 

– N d t ti t d No 

d

e

tections repor

t

e

d

• PDP, 2001-2006 (min detect = N/A): 

– No detections in 4k samples

• USGS data, 1993-2007 (Toccalino et al., 2010) (MRL 

0.02 

μg/L)

– No detections in 647 samples/systems No detections in 647 samples/systems

June 16, 2011 U.S. Environmental Protection Agency 
Diuron: Background 

• Used as a pest c de/ sect c de o 33 c ops c ud g c t us, c

as

a pesticide/insecticide

on 33

c

rops in

cludin

g

cit

rus, c

cane, alfalfa, grapes, asparagus, and pineapple; algaecide in production and ponds

• Production/importation: 1 to 10 million lbs in 1998 (CUS)

• Usage: 9 to 10 million lbs applied annually (OPP’s 2003 RED)

– Up from 4.0 million lbs applied on 22 crops in 37 states in 1992 a

lbs on 21 crops in 39 states in 1997 (NCFAP)

• Industrial releases to surface water: 5 lbs in 2006 (TRI) 

– Down from 260 lbs in 1999

• Total industrial releases: 91,471 lbs in 2008 (TRI)• No natural sources• Expected to be moderately to highly mobile in water, based o

and chemical properties

• Persistent in the environment (biodegrades sometimes)

June 16, 2011 U.S. Environmental Protection Agency 
Diuron: USGS Usage Map (ca. 20

June 16, 2011 U.S. Environmental Protection Agency 
Diuron: Health Effects

• 2003 OPP Risk Assessment• Critical Effect = Cancer; Urinary bladder carcin

– Based on carcinogenicity study in rats and mice Based on carcinogenicity study in rats and mice– Cancer Slope Factor = (0.0191 mg/kg-day)-1

• Non-cancer effect = Hemol

ytic anemia

– Based on chronic dietary study in rats– RfD = 0.003 mg/kg-day; LOAEL = 1.0; UF = 300 

• CCL3 HRL: 1 8 CCL3 HRL:

1.8

μg/L (cancer); 21 g/L (cancer); 21

μg/L (non g/L (non

-ca

ca

• Sensitive populations: None

June 16, 2011 U.S. Environmental Protection Agency 
Diuron: Occurrence

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

μg/L):

– Detections > HRL (1.8 

μg/L) in 1 of 293 systems (0.34%; 72k pop)

– Detections > HRL in 1 of 2k samples (0.04%)

• C lif i 1995 C

alifornia, 1995

-2007 ( i d t t 0 1 2007 (min 

d

e

tec

t = 

0.1

μ

g/L): 

– Detections > HRL in 15 of 990 systems (1.52%)– Detections > HRL in 26 of 9k samples (0.3%)

• Illinois 2001 (min detect = N/A): Illinois, 2001 (min detect

= N/A):

– No detections of 1 sample in 1 system

• PDP, 2002-2006 (min detect = 0.0058 

μg/L): 

– 112 detections of 2k samples (4.8%); No detections 112 detections of 2k samples (4.8%); No detections

> HRL

• USGS data, 1993-2007 (Toccalino et al., 2010) (MRL = 0.0075-

– 31 detections in 587 samples (5.3%); No detections > HRL

• USGS data, 2002-2005 ( pp , g y 

Hopple et al., 2009 and Kin

gsbur

y et al

detect = N/A)

– Phase 1 detections: 3% of 215 GW samples; 30% of 145 SW samp

detections > HRL

– Ph 2 d t ti 7% f 61 GW & 2% f 59 fi i h d GW 

Phase 

2

d

etections: 7% o

f 61 raw GW

& 2% o

f 59 fi

nis

h

e

d GW sam

raw and 24% of 89 finished SW samples; No detections > HRL

June 16, 2011 U.S. Environmental Protection Agency 
Molinate: Background

• Used as a pesticide and herbicide on rice fields in seven s

LA, TX, CA, MS, MO, TN)

• No use permitted in US after 2009 because of toxicity (69 

• Past Usage: ~ 4.9 million lbs applied in 1992 & ~ 3.7 millions lb

1997 (NCFAP)

• Industrial releases to surface water: 0 lbs in 2007 

( ) TRI

)

– Down from an average of 100 lbs (1998-2005)

• Total industrial releases: 0 lbs in 2007 (TRI)• Expected to be moderately mobile in water based on phys

Expected to be moderately mobile in water, based on phys

chemical properties

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

• No natural sources No natural sources

June 16, 2011 U.S. Environmental Protection Agency 
Molinate: USGS Usage Map (ca. 2

June 16, 2011 U.S. Environmental Protection Agency 
Molinate: Health Effects

• 1988 IRIS Risk Assessment• Critical Effect = Reproductive Toxicity; alteration 

morphology; reduced number of viable fetuses/litmorphology; reduced number of viable fetuses/lit

– Rat reproductive study (gavage)– RfD = 0.002 mg/kg-day; NOEL = 0.2 mg/kg-day; UF = 

• CCL3 HRL:14 μg/L (non-cancer)• Sensitive populations: Fetuses (developmental 

neurotoxicity)

June 16, 2011 U.S. Environmental Protection Agency 
Molinate: Occurrence

• UCMR 1 Assessment Monitoring, 2001-2003 (MRL = 0.9 

μg/

– 1 detection (5.7 

μg/L) of 34k samples in 4k systems; No detections 

μg/L)

• California, 1995-2007 (min detect = 2 

μg/L): 

– D t ti i 3 f 2k t (0 13%) N d t ti 1⁄2 HRL D

etections in 

3 o

f 2k systems (0.13%); No 

d

etections > 

1⁄2 HRL

– Detections in 3 of 30k samples (0.02%); No detections > 1⁄2 HRL 

• Illinois, 2001-2003 (min detect = N/A): 

– No detections in 341 samples of 85 systems No detections in 341 samples of 85 systems

• Ohio, 2000-2005 (min detect = N/A): 

– No detections in 153 samples of 24 systems

• PDP 2001 PDP, 2001

-2006 (min detect = N/A): 2006 (min detect

= N/A):

– No detections of 2k samples

• USGS data, 1993-2007 (Toccalino et al., 2010) (MRL = 0.00

μg/L):

– Detections in 3 of 635 samples/systems; No detections > 1⁄2 HRL

June 16, 2011 U.S. Environmental Protection Agency 
Terbufos & Terbufos Sulfone: Backg

• Terbufos is used as a pesticide (e.g., corn & sug

beets)

– ~7.5 million pounds used per year between 1987-1996 

2006 RED)

– 8.7 million lbs applied in 37 states in 1992 and 6.5 mil

37 states in 1997 (NCFAP)

• No production data available from TRI• T b f lf i d d t f t b f Ter

b

u

fos sulfone is a 

degra

d

a

te o

f

ter

b

u

fos

• No natural source

June 16, 2011 U.S. Environmental Protection Agency 
Terbufos: USGS Usage Map (ca. 2

June 16, 2011 U.S. Environmental Protection Agency 
Terbufos & Terbufos Sulfone: Health 

• 2006 OPP Risk Assessment• Critical Effect = Plasma cholinesterase inh

– Based on cholinesterase inhibition from a 2

study in dogs

– RfD 0 00005 mg/kg RfD = 

0.00005 mg/kg

-day; NOAEL 0 005 

day; NOAEL = 

0.005 

day; UF =100

• Studies do not indicate cancer effects Studies do not indicate cancer effects• CCL3 HRL: 0.35 

μg/L (non-cancer)

• Sensitive 

p po

pulations: None

June 16, 2011 U.S. Environmental Protection Agency 
Terbufos: Occurrence

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

μg/L):

– No detects in 2k samples of 295 systems

• California, 2002-2007 

( ) min detect = N/A

):

– No detects in 191 samples of 23 systems

• USGS data, 1993-2007 (Toccalino et al., 2010) (MRL = 0.00

μg/L):

– No detections in 898 samples/systems

• USGS data, 2002-2005 (Hopple et al., 2009 and Kingsbury 

(min detect (min detect

= N/A)

– Phase 1: No detections of 367 samples in 230 systems – Phase 2: No detections in 48 raw & 48 finished water samplesJune 16, 2011 U.S. Environmental Protection Agency 
Terbufos Sulfone: Occurrence

• UCMR 2 Assessment Monitoring, 2008-2010 (MRL = 0.4 

μg

– Detection > HRL (0.35 

μg/L) in 1 of 4,116 systems (0.02%; 45

– HRL is less than the MRL– Sampling not yet complete (data current as of March 1, 2011)

• Iowa (min detect = N/A): 

– No detects in 13 wellsJune 16, 2011 U.S. Environmental Protection Agency 
Questions, Comments or Any Ot

Information to Share?

• Dimethoate• Disulfoton • Diuron• Molinate• Terbufos and Terbufos Sulfone

June 16, 2011 U.S. Environmental Protection Agency 
Contaminants Being Considered 

Evaluated for Regulatory Determina

• Acetochlor and its ESA and OA Degrada

Ali Arvanaghi, USEPA

• Alachlor ESA and OA Degradates• Metolachlor and its ESA and OA Degrad

June 16, 2011 U.S. Environmental Protection Agency 
Acetochlor and its ESA and OA 

De

g g radates: Back

ground

• Used as a herbicide (chloroacetanilide) on field c

popcorn. Fi t i t d i 1994 (OPP’ 2006 TR

Firs

t regis

tere

d in 1994 (OPP’s 2006 TR

• Usage: ~30 to 36 million lbs per year in 1997, 199

2001 (EPA 2001 (EPA s’ Pesticide Industry Sales and Usage 

Pesticide Industry Sales and Usage 

• No natural sources• Expected to be moderately to highly mobile in so• Projected half-life in water is 60 days (PBT Profile

June 16, 2011 U.S. Environmental Protection Agency 
Acetochlor: USGS Usage Map (ca. 

June 16, 2011 U.S. Environmental Protection Agency 
Acetochlor and Degradates: Health E

• IRIS 1993 Risk Assessment• Acetochlor Critical Effect = Histopathology in the testes, ki

liver; increased alanine aminotransferase

– 1-

y g gy ear do

g feedin

g stud

y

– IRIS RfD = 0.02 mg/kg-day; NOAEL = 2 mg/kg-day; UF 

• Acetochlor ESA & OA Critical Effect = Decreased body we

– Degradates unlikely to be carcinogenic and are less tox

Degradates unlikely to be carcinogenic and are less tox

– 90-day feeding study in rats– Supplemental NOEL = 23 mg/kg-day

• Acetochlor CCL3 HRL: 140 

μg/L (non-cancer)

• Acetochlor ESA/OA CCL3 HRL: 161 

μg/L (non-cancer); Pa

surrogate

• Sensitive populations: None

June 16, 2011 U.S. Environmental Protection Agency 
Acetochlor: Occurrence

• UCMR 2 Screening Survey, 2008-2010 (MRL = 2 

μg/L)

– No detections in 11k samples of 1,196 systems– Sampling not yet complete (data current as of March 1 20

Sampling not yet complete (data current as of March

1, 20

• UCMR 1 Assessment Monitoring, 2001-2003 (MRL = 2 

– No detections in 34k samples of 4k systems

• C lif i 2001 C

alifornia, 2001

-2007 ( i d t t N/A) 2007

(

min 

d

e

tec

t = N/A): 

– No detections in 3k samples at 279 systems

• Illinois, 1999-2005 (min detect = 1.6 

μg/L): 

– No detections > 1⁄2 HRL (70 

μg/L) in 3k samples of 897 sy

• Ohio, 2000-2005 (min detect = N/A): 

– No detections in 180 samples at 26 systems

June 16, 2011 U.S. Environmental Protection Agency 
Acetochlor: Occurrence

• PDP, 2006 (min detect = 0.0153 

μg/L):

– No detections > 1⁄2 HRL (70 

μg/L) in 727 samples

• USGS 

( )( Toccalino et al., 2010

)

(MRL = 0.002-0.003 

μ

g ) /L

):

– Detections in 2 of 800 samples/systems

• USGS, 2002-2005 (Hopple et al., 2009 and Kingsbury et a

(p g re

portin

g limit = 0.006 

μg ) /L

)

– Phase 1: Detections in 0.5% of 221 GW samples and 12% o

samples from 230 SW and GW systems; No detections > 1⁄2 

– Phase 2: Detections in 16% of 90 raw SW samples and 11% 

finished SW samples; No detections > 1⁄2 HRL

– Phase 2: No detections of 51 raw and 51 finished GW sampl

June 16, 2011 U.S. Environmental Protection Agency 
Acetochlor ESA: Occurrence

• UCMR 2 Screening Survey, 2008-2010 (MRL = 1 

μg/L):

– Detections in 2 of 1,196 systems; no detections > HRL (161 

– Sampling not yet complete (data current as of March 1, 2011

• PDP, 2006 (min detect = 0.0027 

μg/L):

– No Detections > 1⁄2 HRL (80.5 

μg/L) in 737 samples

• USGS, 00 2 2-2005

( opp e et a , 009 a d gsbu y et a 

Hopple et

al., 2009

a

n

d Kingsbu

r

y et

a

(reporting level = 0.02 

μg/L):

– Phase 1: Detections in 1% of 73 GW samples and 41% of 3

samples from 230 SW and GW systems; No detections > 1⁄2 

– Phase 2: Detections in 25% of 49 raw SW samples and 27% 

finished SW samples; No detections > 1⁄2 HRL

– Phase 2: Detections in 19% of 32 raw GW samples and 19% 

fi i h d GW l N d i 1⁄2 HRL fi

nis

h

e

d GW samples; 

No 

detections > 

1⁄2 HRL

June 16, 2011 U.S. Environmental Protection Agency 
Acetochlor OA: Occurrence

• UCMR 2 Screening Survey, 2008-2010 (MRL = 2 

μg/L):

– No detections in 11k samples of 1,196 systems– Sampling not yet complete (data current as of March 1, 2011

• PDP, 2006 (min detect = 0.0011 

μg/L): 

– No detections > 1⁄2 HRL (80.5 

μg/L) in 737 samples

• USGS

( opp e et a , 009 a d gsbu y et a , 008) Hopple et

al., 2009

a

n

d Kingsbu

r

y et

al., 2008)

(

re

level = 0.02 

μg/L)

– Phase 1: Detections in 1% of 73 GW samples and 39% of 39 

samples from 230 SW and GW systems; No detections > 1⁄2 

– Phase 2: Detections in 32% of 49 raw SW samples and 25% 

finished SW samples; No detections > 1⁄2 HRL

– Phase 2: Detections in 9% of 32 raw GW samples and 19% o

fi i h d GW l N d i 1⁄2 HRL fi

nis

h

e

d GW samples; 

No 

detections > 

1⁄2 HRL

June 16, 2011 U.S. Environmental Protection Agency 
Alachlor Degradates: Backgroun

• Al hl ac

o

r ( tl l t d i d i ki t ) i d (currently regula

t

e

d in 

d

rinking wa

ter

) is use

d as 

herbicide on corn, soybeans, sorghum, peanuts, and beanProduced under names like Lasso and Alanex (OPP’s 199

• U 6 sage: 

6 - 9 illi lb i 2001 (EPA’ P ti id I d t 

9 million lbs in 2001 (EPA’s 

Pesti

cide In

dus

try 

and Sales Report) 

– Down from 55 - 60 million lbs 1987

• I d i l l f 9 lb i 2008 (TRI) In

dustrial releases to surface water: 

9 lbs in 2008 (TRI)

– Down from high of 390 lbs in 1999– Total releases: 368 lbs in 2008

• No natural sources• Alachlor ESA is very mobile in soils and, in water, is estim

be 10 times more soluble than alachlor

June 16, 2011 U.S. Environmental Protection Agency 
Alachlor: USGS Usage Map (ca. 2

Note: Although alachlor is regulated use map provides a sense of where degradates 

June 16, 2011 U.S. Environmental Protection Agency 

Note: Although alachlor is regulated, use map provides

a sense of where degradates 
Alachlor Degradates: Health Effe

• 1998 OPP Risk Assessment• Alachlor ESA Critical Effect = Decreased body weight

– Based on 91 da

yg y drinkin

g water rat stud

y in males

– Supplemental NOEL = 157 mg/kg-day

• Alachlor OA Critical Effect = Cancer (Parent is surrogate)

– Based on carcinogenicity rodent study Based on carcinogenicity rodent study

– Cancer slope factor = (0.08 mg/kg-day)-1

• Alachlor ESA CCL3 HRL: 1,100 

μg/L (non-cancer)

• Alachlor OA CCL3 HRL: 0 4 Alachlor OA CCL3 HRL:

0.4

μg/L (cancer); Parent is surr

g/L (cancer); Parent is surr

• Sensitive populations: None• Alachlor, the parent compound, is already regulated with a

2

μ

g/L

June 16, 2011 U.S. Environmental Protection Agency 
Alachlor ESA: Occurrence

• UCMR 2 Screening Survey 2008 UCMR

2 Screening Survey, 2008

-2010 (MRL = 1 2010 (MRL

=

1

μg/L):

– Detections in 3 of 1,196 systems; no detections > HRL (1,100 – Sampling not yet complete (data current as of March 1, 2011

• PDP 2006 (min detect 0 0028 PDP, 2006 (min detect = 

0.0028

μg/L): 

– No detections > 1⁄2 HRL (550 

μg/L) in 737 samples

• USGS (Hopple et al., 2009 and Kingsbury et al., 2008) (re

l l 0 02 level = 

0.02

μ

g/L): 

– Phase 1: Detections in 35% of 58 GW samples and 59% of 3

samples from 230 SW and GW systems; No detections > 1⁄2 

– Phase 2: Detections in 61% of 49 raw SW samples and 59% 

Phase 2: Detections in 61% of 49 raw SW samples and 59% 

finished SW samples; No detections > 1⁄2 HRL

– Phase 2: Detections in 77% of 17 raw GW samples and 77% 

finished GW samples; No detections finished GW samples; No detections

> 1⁄2 HRL

June 16, 2011 U.S. Environmental Protection Agency 
Alachlor OA: Occurrence

• UCMR 2 Screening Survey, 2008 UCMR

2 Screening Survey, 2008

-2010 (MRL 2010 (MRL

=

2

μg/L):

– No detections in 11k samples of 1k systems– MRL exceeds HRL (0.4 

μg/L)

– Sampling not yet complete (data current as of March 1 2011

Sampling not yet complete (data current as of March

1, 2011

• PDP, 2006 (min detect = 0.001 

μg/L): 

– No detections > 1⁄2 HRL (0.2 

μg/L) in 737 samples

• USGS 2002 USGS, 2002

-2005 (Hopple et al 2009 and Kingsbury et a

(Hopple et al., 2009 and Kingsbury et a

(reporting level = 0.02 

μg/L): 

– Phase 1: Detections in 6% of 73 GW samples and 41% of 39 

from 230 SW and GW systems; Max concentration (1 23 from 230 SW and GW systems; Max concentration (1.23

μg/

g/

– Phase 2: Detections in 50% of 49 raw SW samples and 50% 

finished SW samples; Max concentration (0.26 

μg/L) > 1⁄2 HR

– Phase 2: Detections in 25% of 32 raw GW sam

ples and 28% 

finished GW samples; Max concentration (0.84 

μg/L) > HRL

June 16, 2011 U.S. Environmental Protection Agency 
Metolachlor and its ESA and O

Degradates: Background

• Used as a herbicide on a variety of crops and landscaping 

control

• Manufactured as racemic mixture (metolachlor) and as sing

(S-metolachlor)

• Usage of racemic mixture (EPA Pesticide Industry Sales an

Report)

– 15 - 22 million lbs in 2001, down from 63 - 69 million lbs in 19

• Usage of S-metolachlor (EPA Pesticide Industry Sales and 

Report)

– 20 - 24 million lbs in 2001 up from 16 24 million lbs in 2001, up from 16 - 19 million lbs in 1999 19 million lbs in 1999

• No natural sources• Metolachlor moderately to very mobile in soil (RED)• Metolachlor projected half Metolachlor projected half-life in water is 60 days (PBT Pro

life in water is 60 days (PBT Pro

June 16, 2011 U.S. Environmental Protection Agency 
Metolachlor (ca. 1997) & S-Metola

(ca. 2002): USGS Usage Maps 2002): USGS Usage Maps

June 16, 2011 U.S. Environmental Protection Agency 
Metolachlor and Degradates: Health 

• 1995 OPP Risk Assessment• Metolachlor Critical Effect = Decreased body weight gain

– Based on 1-

y gy g ear feedin

g stud

y in do

gs 

– RfD = 0.1 mg/kg-day; NOEL = 9.7 mg/kg-day; UF = 100

• Class C (Possible human carcinogen) based on 1998 stud• Metolachlor ESA & OA Metolachlor ESA

& OA

– No biologically significant effects– Supplemental NOEL 

≥ 1,000 mg/kg-day

• Metolachlor CCL3 HRL: 700 Metolachlor CCL3 HRL: 700

μg/L (non g/L (non

-cancer) cancer)

• Metolachlor ESA/OA CCL 3 HRL: 

≥ 7,000 

μg/L (non-cance

is surrogate

• S iti l ti N Sensitive populations: 

None

June 16, 2011 U.S. Environmental Protection Agency 
Metolachlor: Occurrence

• UCMR 2 S i S 2008 UCMR

2

Screening 

Survey, 2008

-2010 (MRL 1 2010 (MRL = 

1

μ

g/L):

– Detections in 3 of 1,196 systems; no detections > HRL (700 

μg/L)

– Sampling not yet complete (data current as of March 1, 2011)

• UCM Round 2 cross UCM Round

2 cross

-section 1993 section, 1993

-1997 (min detect = 0 01 1997 (min detect

=

0.01

μg/L

– Detections in 116 of 13k systems (0.9%); no detections > HRL– Detections in 211 of 34k samples (0.6%); no detections > HRL

• California, 1995 California, 1995

-2007 (min detect 2007 (min detect

= 0.1

μg/L):

– No detections > 1⁄2 HRL (350 

μg/L) in 24k samples at 2k systems

• Illinois, 1999-2005 (min detect = 0.3 

μg/L): 

– No detections in 3k samples at 875 systems

• North Carolina, 1998-2005 (min detect = 0.5 

μg/L): 

– No detections > 1⁄2 HRL in 14k samples of 2,477 systems

• Ohio, 1999-2005 (min detect = 0.1 

μg/L): 

– No detections > 1⁄2 HRL in 2k samples of 821 systems

June 16, 2011 U.S. Environmental Protection Agency 
Metolachlor: Occurrence

• Region 9 Tribes, 1998-2005 (min detect = N/A): 

– No detections in 734 samples at 225 systems

• South Dakota, 1993-2007 (min detect = N/A): 

– No detections in 2k samples at 255 systems

• Texas, 1998-2007 (min detect = 0.1 

μg/L): 

– No detections > 1⁄2 HRL (350 

μg/L) in 12k samples at 2,252 systems

• Florida, 2004-2007 (min detect = N/A): 

– No detections in 28 samples at 6 systems

• Wisconsin, 1984-1999 and 2000-2008 (min detect = 0.1 

μg/L): 

– N d t ti 1⁄2 HRL i 3k l t 1 175 t No 

d

etections > 

1⁄2 HRL in 3k samples at 1,175 systems

• Wisconsin, 2000-2009 (min detect = 0.1 

μg/L): 

– No detections > 1⁄2 HRL in 2k samples at 915 systems

June 16, 2011 U.S. Environmental Protection Agency 
Metolachlor: Occurrence

• PDP, 2006 (min detect = 0.0025 

μg/L): 

– No Detections > 1⁄2 HRL (350 

μg/L) in 727 samples

• USGS (Toccalino et al., 2010) (MRL = 0.002-0.006 

μg/L)

– No detections > HRL in 870 samples/systems

• USGS (Hopple et al., 2009 and Kingsbury et al., 2008) (reporting 

0.006 

μg/L)

– Phase 1: Detections in 11% of 221 GW samples and 51% o

Phase 1: Detections in 11% of 221 GW samples and 51% o

samples from 230 SW and GW systems; No detections > 1⁄2 

– Phase 2: Detections in 59% of 90 raw SW samples and 54% 

finished SW samples; No detections finished SW samples; No detections

> 1⁄2 HRL

– Phase 2: Detections in 13% of 64 raw GW samples and 11% 

finished GW samples; No detections > 1⁄2 HRL

June 16, 2011 U.S. Environmental Protection Agency 
Metolachlor ESA: Occurrence

• UCMR 2 Screening Survey, 2008-2010 (MRL = 1 

μg/L):

– Detections in 19 of 1,196 systems; no detections > HRL (7,000 

μg/L

– Sampling not yet complete (data current as of March 1, 2011)

• PDP 2008 ( i d t t 0 0006 PDP, 2008 (min 

d

e

tec

t = 

0.0006

μ

g/L): 

– No detections > 1⁄2 HRL (3,500) in 737 samples

• USGS (Hopple et al., 2009 and Kingsbury et al., 2008) (reporting 

0 02 . μg/L)

– Phase 1: Detections in 29% of 73 GW samples and 69% of 39 SW s

230 SW and GW systems; No detections > 1⁄2 HRL

– Phase 2: Detections in 68% of 49 raw SW samples and 59% of 48 fi

samples; No detections > 1⁄2 HRL

– Phase 2: Detections in 47% of 32 raw GW samples and 41% of 32 f

samples; No detections > 1⁄2 HRL

June 16, 2011 U.S. Environmental Protection Agency 
Metolachlor OA: Occurrence

• UCMR 2 Screening Survey, 2008-2010 (MRL = 2 

μg/L):

– Detections in 1 of 1,196 systems; no detections > HRL (7,000 

μg/L)

– Sampling not yet complete (data current as of March 1, 2011)

• PDP 2006 ( i d t t 0 0053 PDP, 2006 (min 

d

e

tec

t = 

0.0053

μ

g/L): 

– No detections > 1⁄2 HRL (3,500) in 737 samples

• USGS (Hopple et al., 2009 and Kingsbury et al., 2008) (reporting 

0 02 . μg/L)

– Phase 1: Detections in 15% of 73 GW samples and 67% of 39 SW s

230 SW and GW systems; No detections > 1⁄2 HRL

– Phase 2: Detections in 77% of 49 raw SW samples and 59% of 48 fi

samples; No detections > 1⁄2 HRL

– Phase 2: Detections in 38% of 32 raw GW samples and 34% of 32 f

samples; No detections > 1⁄2 HRL

June 16, 2011 U.S. Environmental Protection Agency 
Questions, y Comments or Any Ot

Information to Share?

• Acetochlor and its ESA and OA Degradate• Alachlor ESA and OA Degradates• Metolachlor and its ESA and OA Degrada

Metolachlor and its ESA and OA Degrada

June 16, 2011 U.S. Environmental Protection Agency 
Next Steps

• Publish preliminary regulatory determina

for public comment by mid for public comment by mid-2012.

• After considering comments publish fina

After considering comments, publish fina

regulatory determinations by August 201

June 16, 2011 U.S. Environmental Protection Agency 
Appendices

June 16, 2011 U.S. Environmental Protection Agency 
Appendix A: Unregulated CCL 3 Contamina

106 Chemicals and 12 Microbes

1,1,1,2-Tetrachloroethane 1,1-Dichloroethane 1,2,3-Trichloropropane 1,3-Butadiene 1,3-Dinitrobenzene 1 4 Dioxane

Cyanotoxins (3)Dicrotophos Dimethipin Dimethoate Disulfoton Diuron

Molybdenum Nitrobenzene Nitroglycerin N-Methyl-2-pyrrolidone N-Nitrosodiethylamine (NDEA) N nitrosodimethylamine (NDMA)

TrieTripUretVanVinc

1,4-Dioxane Zira

17 alpha-Estradiol 1-Butanol 2-Methoxyethanol 2-Propen-1-ol 3-Hydroxycarbofuran (degradate) 4,4'-Meth

ylenedianiline 

Diuron

EquileninEquilin Erythromycin Estradiol (17-beta) Estriol Estrone 

N-nitrosodimethylamine (NDMA)

N-Nitroso-di-n-propylamine (NDPA) N-Nitrosodiphenylamine N-nitrosopyrrolidine (NPYR) Norethindrone (19-Norethisterone) n-Propylbenzene o-Toluidine 

Zira

AdeCaliCamEnte

y Esc

Acephate Acetaldehyde Acetamide Acetochlor Acetochlor ethanesulfonic acid (ESA) Acetochlor oxanilic acid (OA) Acrolein

Ethinyl Estradiol (17-alpha) Ethoprop Ethylene glycol Ethylene oxide Ethylene thiourea Fenamiphos Formaldehyde (formerly)

Oxirane, methylOxydemeton-methyl OxyfluorfenPerchlorate Perfluorooctane sulfonic acid (PFOS)Perfluorooctanoic acid (PFOA) P th i

HeliHepLegMycNaeSalm

Acrolein Shig

Alachlor ethanesulfonic acid (ESA)Alachlor oxanilic acid (OA) alpha-Hexachlorocyclohexane (former) Aniline Bensulide Benz

yl chloride 

Formaldehyde (formerly)Germanium Halon 1011 (Bromochloromethane) HCFC-22 Hexane Hydrazine Mestranol 

Permethrin

Profenofos Quinoline RDX sec-Butylbenzene Strontium 

Tebuconazole

Shig

y

Butylated hydroxyanisole Captan Chlorate (also D-DBP) Chloromethane (Methyl chloride) Clethodim Cobalt C h d id

Methamidophos Methyl bromide (Bromomethane)Methyl tert-butyl ether Metolachlor Metolachlor ethanesulfonic acid (ESA)Metolachlor oxanilic acid (OA) M li t

Tebuconazole

Tebufenozide Tellurium Terbufos Terbufos sulfone ThiodicarbThiophanate-methyl 

Cumene hy

droperoxide 

M

olinate Toluene diisocyanate 

Tribufos 

June 16, 2011 U.S. Environmental Protection Agency 
Appendix B: Contaminants on the Second Un

Contaminant Monitoring Regulation (UCM

10 Assessment Monitoring• 3 Explosive

 hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)

246 trinitrotoluene (TNT)

15 Screening Survey• 9 Acetanilide pesticides/degrad

 Acetochlor 

 2,4,6-trinitrotoluene (TNT)  Acetochlor ESA 1,3-dinitrobenzene

• 7 Insecticides and Flame Retardants

 Dimethoate

 Acetochlor ESA Acetochlor OA Alachlor Alachlor ESA Alachlor OA

 Terbufos sulfone 5 Brominated Flame Retardants

 Metolachlor Metolachlor ESA Metolachlor OA

• 6 Nitrosamines 6 Nitrosamines

 N-nitroso-diethylamine (N N-nitroso-dimethylamine  N-nitroso-di-n-butylamine  N-nitroso-di-n-propylami N-nitroso-meth l th l 

th

yleth

ylam

 N-nitroso-pyrrolidine (NP

June 16, 2011 U.S. Environmental Protection Agency 
Appendix C: What Factors Do We Consid

and How Do We Develop Standards? and How Do We Develop Standards?

Human Health Effects

Analytical Test 

Methods

Te

Set Public Health Goal or 

Maximum Contaminant Level 

Goal (MCLG)

Methods

Set legally, enforceable 

Maximum Contaminant Level (MCL)*

Occurrence Ec

or Treatment Technique (TT)*

Also list treatment technologies; specify 

methods to measure, how often monitor, 

when/what to report to state Occurrence d th bli t Ec

C

an

d the public, etc

Public and Expert Input

* Maximum Contaminant Level (MCL) - the highest level or amount of a contaminant that EPA allow

*Treatment Technique (TT) – a prescribed process intended to reduce the level of a contaminant in d

June 16, 2011 U.S. Environmental Protection Agency 
A di D Ni i O Appendix 

D: Nitrosamines 

Occurren

in Ambient Water (STORET) 

Nitrosamine 

Compounds 

in CCL3

#Samples 

in 

Dataset

#Samples 

with 

Detection

#Sample 

Sites in 

Dataset

#

D

NDMA* 599 0 261 

NDEA** 3 0 3 

NPYR** 5 0 5 

NDPA* 1,508 22

(1 5%)

602 

(1.5%) 

NDPhA* 1,268 31 

(2.4%)

470 

* From both GW & SW From both GW

& SW

** From SW 

June 16, 2011 U.S. Environmental Protection Agency 
Appendix E: Appendix E:

NDMA UCMR2 Inventory InformatioNDMA UCMR2 Inventory Informatio

and 

Occurrence by Water Type and 

Monitoring Location (Based on UCM

Data of March 1, 2011 Version)

U.S. Environmental Protection Agency 

June 16, 2011
Nitrosamines: UCMR 2 Invento

Information (as of March 1, 201

(NDMA as an 

example)

Systems 

≥ 100 k

Systems 

between 100 k 

& 10 k

Systems

< 10 k

O

Number of 

Samples

10,733

(60%)

3,950

(22%)

3,233

(18%)

(

Nb f um

ber o

f 398 318 480 

Systems in 

Dataset

398 318 480

Number of Number of 398 320 480 

Systems in 

UCMR2 

Screening 

398

(All)

320 480

U.S. Environmental Protection Agency 

Survey Design

June 16, 2011
Summary Statistics among NDMA Detec

Nitrosamines: Occurrence (con

y g

Surface Water Systems: Disinfectant Types 

with w

Chlorine Chlo

Number of Detections 171 

Detection Rate 4% 3

Mean (ng/L) 8.4 

Median (ng/L) 3.4 

Maximum (ng/L) 84.6 

%M t * ≥ 10 /L 0 8% 7 %Measurements* ≥ 10 ng/L 0.8% 7

* Among all of measurements June 16, 2011 U.S. Environmental Protection Agency
Summary Statistics among NDMA Detections 

Nitrosamines: Occurrence (con

Water Systems with Chlorine: Monitoring Lo

At EP A

Number of Detections 87 

Detection Rate 4.0% 4

Mean (ng/L) 7.8 

Median

( g/ ) n

L

) 3.2 

Maximum (ng/L) 61.7 

%Measurements*  ≥ 10

ng/L 0.5% 

* Among all of measurements

June 16, 2011 U.S. Environmental Protection Agency
Summary Statistics among NDMA Detections 

Nitrosamines: Occurrence (con

Summary Statistics among NDMA Detections 

Water Systems with Chloramines: Monitoring 

At EP A

Number of Detections 326 

D t ti e

tection R t a

t

e 28 6%. 5

Mean (ng/L) 9.8 

M di e an ( /L) ng 4 1. 

Maximum (ng/L) 470 

%Measurements*

≥ 10 ng/L 5 8% 1

%Measurements*

≥ 10 ng/L

5.8% 1

* Among all of measurements

June 16, 2011 U.S. Environmental Protection Agency
Summary Statistics among NDMA Detectio

Nitrosamines: Occurrence (con

Summary Statistics among NDMA Detectio

Chlorine: Water Types

GW 

Number of Detections 85 

Detection Rate 1 4%. 4 

Mean (ng/L) 4.7 

M di e an ( /L) ng 3 1. 

Maximum (ng/L) 55.0 

%Measurements*  ≥ 10 ng/L 0.08% 

* Among all of measurements

June 16, 2011 U.S. Environmental Protection Agency
S St ti ti NDMA D t ti 

Nitrosamines: Occurrence (con

Summary St

ati

stics among NDMA

D

e

tectio

Chloramines: Water Types

GW 

Number of Detections 60 

Detection Rate 11 7%. 3

Mean (ng/L) 3.7 

Median (ng/L) 2 8. 

Maximum (ng/L) 10 

%Measurements*  ≥ 10

ng/L 0.2% 

* Among all of measurements

June 16, 2011 U.S. Environmental Protection Agency
Appendix F: Timeline

Proposed

Regulations Due

For Positive

Publish Final

Determinations

Publish

Preliminary

Determinations

Re

2013 2015

2016

For Positive

2012 2014

Publish

Final UCMR3

Complete UCMR3

Assessment

2012 2014

Begin UCMR3

Assessment

Monitoring Monitoring

143