Phase II Training
July 10-11, 1991
Riverview Inn
424 Minnesota Avenue
Kansas City, Kansas 66101
Wednesday, July 10
10:00 A.M. Welcome, Introduction
10:15
10:30
11:15
11:45
12:00 P.M.
1:00
1:45
2:30
2:45
3:30
4:15
5:00
Agenda Review
MCL, MCLG Development: IOCS,
VOCs, SOCs: Health Effects,
Treatment Technique Requirements
Pesticides
Introduction to Standardized
Monitoring Framework (SMF):
3/6/9 Cycle, Waivers
LUNCH
Phase II: The Making of
a Regulation
SMF - Application: Asbestos,
Nitrate, Nitrite
BREAK (15 minutes)
SMF - Application: IOCS
SMF - Application: VOCs
SMF - Application: SOCs
ADJOURN
Ralph Langemeier
Ralph Flournoy
Mary Williams
Ken Buchholz
Pat Ritchey
Mike Muse
Talva Hayes
Elizabeth
Murtagh Yaw
Pat Ritchey
Stan Calow
Ralph Flournoy
-------
Phase II Training
July 10-11, 1991
Riverview Inn
424 Minnesota Avenue
Kansas City, Kansas 66101
Thursday, July 11
8:00 A.M. Q & A on Previous Day's Topics
8:45
9:15
10:15
10:30
11:30
12:00 P.M.
1:00
1:45
2:30
2:45
3:15
4:00
SMF - Application: Unregulated
Contaminants
Vulnerability Assessment
Application Form and Guidance
BREAK (15 minutes)
Compliance Determinations and
FRDS Reporting
Variances and Exemptions
LUNCH
Wellhead Protection:
Relationship to Phase II
Laboratory Testing and
Certification
BREAK
Economic Analysis of the
Phase II Rule
Primacy Timeline Requirements
and Applications
ADJOURN
Ralph Flournoy
Glen Yager
Mike Muse
Stan Calow
Glen Yager
Pat Costello
Dale Bates
Mike Muse
Ralph Flournoy
Ralph Flournoy
-------
SAFE DRINKING WATER ACT
LABORATORY
CERTIFICATION
-------
LABORATORY CERTIFICATION
Discussion Issues
• REGULATIONS/GUIDELINES
• BASIC ORGANIZATION & RESPONSIBILITIES
• CERTIFICATION REQUIREMENTS &
PROCEDURES
• JANUARY 1991 REGULATIONS
-------
LABORATORY CERTIFICATION
Regulations/Guidelines
REGULATORY AUTHORITY:
40 CFR Parts 141 & 142
GUIDELINES:
Manual for the Certification of Laboratories
Analyzing Drinking Water. U.S. EPA, Office
of Water, April 1990 (3rd Edition)
-------
LABORATORY CERTIFICATION
Primary Participants
EPA OFFICE OF DRINKING WATER
EPA OFFICE OF RESEARCH & DEVELOPMENT
EMSL - CINCINNATI
EMSL - LAS VEGAS
EPA REGIONS
PRIMACY STATES
-------
LABORATORY CERTIFICATION
Certifying Authorities
LABORATORY CERTIFYING AUTHORITIE
EPA REGIONAL LABORATORY EMSL-CI/EMSL-LV
STATE PRINCIPAL LABORATORY REGIONAL
SYSTEM ADMINISTRATOR
LOCAL LABORATORIES STATE PRIMACY AGENCY
-------
LABORATORY CERTIFICATION
Basic Requirements
ON-SITE EVALUATION
WATER SUPPLY PERFORMANCE EVALUATION
(PE) STUDIES
ANALYTICAL METHODOLOGY
NOTIFICATION OF MAJOR CHANGES
(PERSONNEL, EQUIPMENT OR LAB
LOCATION WHICH MIGHT IMPAIR
ANALYTICAL CAPABILITIES)
-------
LABORATORY CERTIFICATION
Categories
CERTIFIED - meets the minimum requirements
of the applicable regulations and
certification manual; demonstrates
ability to consistently produce valid
data
PROVISIONALLY CERTIFIED - has some minor
deficiencies, but demonstrates ability
to consistently produce valid data
NOT CERTIFIED - has major deficiencies and
cannot consistently produce valid
data within specified acceptance
limits
-------
LABORATORY CERTIFICATION
Basic Regional Procedures
o ON-SITE EVALUATIONS - Once/3 years
Chemistry/Microbiology - RQAM
Radiochemistry - EMSL-CI
o WATER SUPPLY PE STUDIES - Twice/year
Chemistry/Microbiology - EMSL-CI
Radiochemistry - EMSL-LV
o TECHNICAL ASSISTANCE - Ongoing
Quality Assurance Office, ENSV
-------
LABORATORY CERTIFICATION
Certification Parameters
GROUPS
INORGANICS
ORGANICS
PARAMETERS
Metals - 8
Fluoride
Nitrate
Pesticides
Herbicides - 2
Insecticides - 4
Total Trihalomethanes
(TTHMs) - 4
Volatile Organic Chemicals
(VOCs)
Regulated - 8
Unregulated - 51
-------
LABORATORY CERTIFICATION
Certification Parameters
GROUPS
MICROBIOLOGY
RADIOCHEMISTRY
PARAMETERS
Coliform Bacteria
Gross Alpha Particles
Radium-226 & -228
Gross Beta Particles
Photon Emitters
Tritium
Strontium-89 & -90
lodine-131
Cesium-134
Uranium
-------
LABORATORY CERTIFICATION
Current States' Status - IOWA
STATE PRINCIPAL LABS PARAMETER GROUPS STATUS
University Hygienic Chemistry (Nitrate,
Laboratory (UHL), Pest, TTHMs, VOCs) Certified (6/12/94)
Iowa City Microbiology Certified (6/12/94)
Radiochemistry Certified (6/12/94)
UHL, Des Moines Chemistry (Metals) Certified (6/12/94)
Microbiology Certified (6/12/94)
-------
LABORATORY CERTIFICATION
Current States' Status - KS & NE
PRINCIPAL STATE LABS PARAMETER GROUPS STATUS
Kansas Dept of Health
& Environment (KDHE),
Div of Laboratories
& Research
Chemistry (Inorg,
Pest, TTHMs, VOCs)
Microbiology
Radiochemistry
Certified (6/12/94)
Certified (6/12/94)
Certified (6/12/94)
Nebraska Dept of
Health
Chemistry (Inorg,
Pest, TTHMs, VOCs)
Microbiology
Radiochemistry
Certified (6/12/94)
Certified (6/12/94)
Certified (6/12/94)
-------
LABORATORY CERTIFICATION
Current States' Status - MISSOURI
STATE PRINCIPAL LABS PARAMETER GROUPS STATUS
MO Dept of Health
Jefferson City
Poplar Bluff
Springfield
MO Dept of Natural
Resources, Lab
Services Program
St Louis County Dept
of Community Health
Chemistry (Inorg,
Pest, TTHMs, VOCs)
Microbiology
Microbiology
Microbiology
Chemistry (Pest,
TTHMs, VOCs)
Radiochemistry
Certified (6/12/94)
Certified (6/12/94)
Certified (6/12/94)
Certified (6/12/94)
Certified (5/31/92)
Certified (12/31/91)
-------
LABORATORY CERTIFICATION
Comparison - Current & Phase II Regulations
CURRENT REGULATIONS
ANALYZED CONTAMINANTS:
Regulated:
10 Inorganic
8 VOCs
6 Pesticides
Unregulated:
34 VOCs
PERFORMANCE CRITERIA:
Quantitative acceptance limits
established in Lab Cert Manual
& by EMSL-CI from WS Studies
PHASE II REGULATIONS
ANALYZED CONTAMINANTS:
Regulated:
10 Inorganics
18 VOCs
14 Pesticides/PCBs
4 Pesticides Proposed
Unregulated:
6 Inorganics
24 Organ ics
PERFORMANCE CRITERIA:
Quantitative acceptance limits
and Method Detection Limits
established in the regulations
-------
INORGANIC CONTAMINANTS
(lOCs)
Current MCL New MCL New MCLG
Contaminant (ma/I) (ma/I) (mg/l)
Arsenic 0.05
Asbestos -- 7 MFL 7 MFL
Barium 1 (2)* (2)*
Cadmium 0.010 0.005 0.005
Chromium 0.05 0.1 0.1
Fluoride 4.0 4.0
Lead 0.05
Mercury 0.002 0.002 0.002
Nitrate 10(as N) 10(as N) 10(as N)
Nitrite -- Kas N) Kas N)
Nitrate/Nitrite -- 10(as N) 10(as N)
Selenium 0.01 0.05 0.05
Silver 0.05
* Proposed MFL • Million Fibers/liter larger than 10 urn
-------
VOLATILE ORGANIC CHEMICALS
(VOCs)
Contaminant
Vinyl chloride
Benzene
Carbon tetrachloride
1,2-Dichloroethane
Trichloroethylene
para -Dichlorobenzene
1,1 -Dichloroethylene
1,1,1 -Trichloroethane
cis- 1,2-Dichloroethylene
trans- 1,2-Dlchlorethylene
1,2-Dichloropropane
Ethylbenzene
Monochlorobenzene
o-Dichlorobenzene
Styrene
Tetrach loroethy lene
Toluene
Xylenes, Total
Current MCL
(mg/l)
0.002
0.005
0.005
0.005
0.005
0.075
0.007
0.2
New MCL
(mg/l)
New MCLG
(ma/l)
0.07
0.1
0.005
0.7
0.1
0.6
0.1
0.005
1
10
0.07
0.1
0
0.7
0.1
0.6
0.1
0
1
10
-------
PESTICIDES/PCBs
Contaminant
2,4-D
2,4,5-TP
Lindane
Methoxychlor
Toxaphene
Alachlor
Aldicarb
Aldicarb sulfone
Aldicarb sulfoxide
Atrizine
Carbofuran
Chlordane
Dibromochloropropane
Ethylene dibromide (EDB)
Heptachlor
Heptachlor epoxide
PCBs
Pentachlorophenol
Current MCL
(mg/l)
0.01
0.01
0.004
0.1
0.005
New MCL
(mg/l)
New MCLG
(mg/l)
0.07
0.05
0.0002
0.04
0.003
0.002
(0.003)*
(0.003)*
(0.003)*
0.003
0.04
0.002
0.0002
0.00005
0.0004
0.0002
0.0005
(0.001)*
0.07
0.05
0.0002
0.04
0
0
(0.001)*
(0.002)*
(0.001)*
0.003
0.04
0
0
0
0
0
0
(0)*
*Proposed
-------
LABORATORY CERTIFICATION
Major Impacts
MORE ANALYTES
MORE ANALYTICAL METHODS
MORE STRINGENT PERFORMANCE CRITERIA
ELIMINATION OF LIMITED USE ALTERNATE
TEST PROCEDURES
TERMINATION OF FREE SUPPLY OF
REFERENCE SAMPLES (CALIBRATION
STANDARDS & QC) FROM EMSL-CI;
WS PE STUDIES NOT AFFECTED
-------
APPROVED ANALYTICAL METHODS
REGULATED INORGANIC CONTAMINANTS
CONTAMINANTS
Arsenic
Asbestos
Barium
Cadmium
Chromium
Fluoride
Lead
Mercury
Nitrate (as N)
Nitrite (as N)
Selenium
EPA METHODS
200.7A, 206.2, 206.3, 206.4
TEM*
200.7A, 208.1, 208.2
200.7A, 213.1, 213.2
200.7A, 218.1, 218.2
340.1, 340.2, 340.3
200.7A, 239.1, 239.2
245.1, 245.2
300.0, 352.1, 353.1, 352.2,
352.3
300.0, 353.2, 353.3, 354.1
270.2, 270.3
^Transmission Electron
Microscopy (EPA 600/4-83-043)
-------
APPROVED ANALYTICAL METHODS
REGULATED ORGANIC CONTAMINANTS
CONTAMINANTS EPA METHODS
Total Trihalomethanes (TTHM) 501.1, 501.2, 501.3
Volatile Organics (VOCs) 502.1, 502.2, 503.1
524.1, 524.2
Alachlor 505, 507, 525
Aldicarb 531.1
Aldlcarb sulfone 531.1
Aldicarb sulfoxide 531.1
Atrazine 505, 507, 525
Carbofuran 531.1
Chlordane 505, 507, 525
Dibromochloropropane (DBCP) 504
2,4-D 515.1
Endrin 505, 508
-------
APPROVED ANALYTICAL METHODS
REGULATED ORGANIC CONTAMINANTS
CONTAMINANTS EPA METHODS
Ethylene dibromide (EDB) 504
Heptachlor 505, 508, 525
Heptachlor epoxide 505, 508, 525
Lindane 505, 508, 525
Methoxychlor 505, 508, 525
PCBs (Screening) 505, 508
PCBs (Quantitative as
decachlorobiphenyl) 508A
Pentachlorophenol 515.1, 525
Toxaphene 505
2,4,5-TP (Silvex) 515.1
-------
INORGANIC CONTAMINANTS
(lOCs)
Contaminant
Arsenic
Asbestos
Barium
Cadmium
Chromium
Fluoride
Lead
Mercury
Nitrate
Nitrite
Nitrate/Nitrite
Selenium
Silver
Current MCL
(mg/l)
0.05
1
0.010
0.05
4.0
0.05
0.002
10(as N)
0.01
0.05
New MCL
(ma/l)
NC
7 MFL
2*
0.005
0.1
4.0
NC
0.002
10(as N)
Kas N)
10(as N)
0.05
New MCLG
(mg/l)
NC
7 MFL
2*
0.005
0.1
NC
0.002
10(as N)
Kas N)
10(as N)
0.05
* Effective date of Janaury 1, 1993; all others July 30,1992
MFL • Million Fibers/ liter larger than 10 um
NC • No Change
-------
VOLATILE ORGANIC CHEMICALS
(VOCs)
Contaminant
Vinyl chloride
Benzene
Carbon tetrachloride
1,2-Dichloroethane
Trichloroethylene
para -Dichlorobenzene
1,1 -Dichloroethylene
1,1,1 -Trichloroethane
cis- 1,2-Dichloroethylene
trans- 1,2-Dichlorethylene
1,2-Dichloropropane
Ethylbenzene
Monochlorobenzene
o-Dichlorobenzene
Styrene
Tetrachloroethylene
Toluene
Xylenes, Total
NC • No Change
Current MCL
(mg/l)
New MCL
(ma/I)
New MCLG
(ma/l)
0.002
0.005
0.005
0.005
0.005
0.075
0.007
0.2
--
--
Ml Mi
M •»
--
--
--
NC
NC
NC
NC
NC
NC
NC
NC
0.07
0.1
0.005
0.7
0.1
0.6
0.1
0.005
1
10
NC
NC
NC
NC
NC
NC
NC
NC
0.07
0.1
0
0.7
0.1
0.6
0.1
0
1
10
-------
PESTICIDES/PCBs
Contaminant
2,4-D
2,4,5-TP
Lindane
Methoxychlor
Toxaphene
Alachlor
Aldlcarb
Aldicarb sulfone
Aldicarb sulfoxide
Atrizine
Carbofuran
Chlordane
Dibromochloropropane
Ethylene dibromide (EDB)
Heptachlor
Heptachlor epoxide
PCBs
Pentachloropheno!
Current MCL
(ma/1)
0.01
0.01
0.004
0.1
0.005
New MCL
(mo/l)
0.07
0.05
0.0002
0.04
0.003
0.002
0.003*
0.003*
0.003*
0.003
0.04
0.002
0.0002
0.00005
0.0004
0.0002
0.0005
0.001*
New MCLG
(mg/l)
0.07
0.05
0.0002
0.04
0
0
0.001*
0.001*
0.001*
0.003
0.04
0
0
0
0
0
0
0*
*Effective date of January 1, 1993; all others July 30, 1992
-------
Summary of Phase II Requirements
KEY: W - Waiver, S W - Surface Water, GW - Ground Water, GF - Grandfaihered Data; SD - State Discretion; VA - Vulnerability Assessment
PERIOD ~~
1st Three Yearsj
2nd Three Years|
Asbestos
No Waiver
Waiver I I I ~l ,
tw (3 Years, Effectively 9 Yi
Nitrate
sw
av
Transient PWS
I • I | . | | . |
No Waivers Allowed
No Waivers Allowed
tw (Ellective 9 Years)
1
w (Effective 9 Years)
....
GD G~] GU
....
1 .".. 1
1 • 1
1 ..'• 1
1 • 1
1 • 1
I
rw
(Effective 9 Years)
1 • • • « 1
r
1
t w (Effective 6 Years) t VA t w
1
(Effective 6 Years)
Nitrite
lOCs
GW.NoGF
GW.GF
GW.GF
SW.NoGF
SW.GF
SW.GF
VOCs
GW. NoGF. >3Yrs
GW.GF
GW.NoGF. >3Yrs
GW.GF.,3Yrs I • I | • | | • ||
SW.NoGF
SW.GF
SW.GF
SOCs & Pesticides
> 3,300
NoGF
GF
<= 3,300
NoGF
Both
Waiver
t w (Effective 3 Years)
Unregulated Contaminants
Inorganics
SO I I SO
3rd Three Years]
1 st Three Years]
SO I I SD
SO I I SD
t w (Effective 9 Years) |
t w (Effective 9 Years)
t w (Effective 9 Years) |
t w (Effective 6 Years) t VA
t w (Effective 6 Years)
1 ...- 1
GD n~i n~i
:ldes
1 .... |
1 • • 1
1 .... 1
1
1
....
n~i r~~i n~i
| ....
GD n~i nn
so
r w (Effective 6 Years)
• •
. .
•
.
i
i
i
i
i i
— i
so
t w (Effective 6 Years)
1
1
1
1 • 1
1 1
(Effective 3 Years)
(Effective 3 Years) t w (Effective 3 Years)
< 150 Connections - Letter of Availability to State
X]
XI
LX
>150. No Detect
>150, Detect
>150, No Detect
t w No Samples Required
Organics
< 150 Connections • Letter of Availability to Stale
>150 Connections |
.150. Waiver j
t w No Monitoring Required
cxn
LXl U3
LX LX Xl
Xl Xl
IX Xl Xl
X] Xl Xl
-------
•%
Til J
Summary of Phase II
Regulations
National Primary Drinking Water
Regulations for 38 Inorganic and
Synthetic Organic Chemicals
Apr ill 991
Office of Drinking Water
U.S. Environmental Protection Agency
Washington, DC
-------
Preface
Note to the Reader
The U.S. Environmental Protection Agency (EPA) promulgated
National Primary Drinking Water Regulations for 38 inorganic and
synthetic organic chemicals on January 30,1991 (Phase II Rule). The.
following packet of materials was developed in response to this
rulemaking effort and is intended for use by EPA regional officials,
state and water system personnel. The packet is organized into two
sections. The first section consists of a general fact sheet which sum-
marizes the Phase II regulatory requirements. The second section (or
appendices) of the package consists of a series of eight fact sheets and
flow charts which describe the compliance monitoring requirements
for the various groups of contaminants regulated under Phase II. The
entire package of materials has been designed such that individual
sections can be used by themselves or together.
-------
Table of Contents
Phase II Fact Sheet
Summary
Regulatory Impact
Phase 13 National Primary Drinking Water Regulations (Tables)
Compliance Monitoring Requirements (Table)
Regulatory Development Information
Appendices
• Fact Sheet on Standardized Monitoring Framework
• Fact Sheet on Asbestos
-Standardized Monitoring Framework: Asbestos
-Asbestos Flow Chan
• Fact Sheet on Nitrate
-Nitrate Flow Chan
• Fact Sheet on Nitrite
-Nitrite Flow Chan
• Fact Sheet on Inorganics
-Standardized Monitoring Framework: Inorganics
-Inorganics Row Chan
• Fact Sheet on Volatile Organic Chemicals
-Standardized Monitoring Framework: Volatile Organic Chemicals
-Volatile Organic Chemicals Flow Chan
• Fact Sheet on Pesticides
-Standardized Monitoring Framewo.k: Pesticides
-Pesticides Flow Chan
• Fact Sheet on Unregulated Contaminants
-Standardized Monitoring Framework: Unregulated Contaminants
-Unregulated Contaminants Flow Chans: Inorganics and Pesticides
-u-
-------
Phase II Fact Sheet
National Primary Drinking Water Regulations for
38 Inorganic and Synthetic Organic Chemicals
April 1991
Summary
The January 30,1991 rulemakings:
• Promulgate Maximum Contaminant Level Goals (MCLGs) and Maximum
Contaminant Levels (MCLs) or treatment technique requirements for 33
contaminants; and,
• Repropose MCLGs and MCLs for aldicarb, aldicarb sulfoxide. aldicarb sul-
fone, pentachlorophenol, and barium.
When both rulemakings are final:
• The addition of the 38 contaminants regulated under Phase n will nearly
double the number of regulated contaminants from the 38 contaminants
currently regulated to 64 when both rulemakings become effective in 1992.
Of the 38 Phase n contaminants, 27 are newly regulated. The remaining 11
contaminants were previously regulated and were revised. Phase II will
establish:
• 12 new pesticide MCLs for a total of 18;
• Two new inorganic MCLs and the deletion of one MCL for a total of 11:
• 10 new volatile organics MCLs for a total of 18;
• Treatment technique requirements for two contaminants; and
• One additional MCL for PCB&
These rules also include additional provisions for:
• Analytical methods and laboratory performance requirements;
• Best Available Technologies (BATs) for compliance with the MCLs and for
the purpose of issuing variances;
• Secondary standards for silver (0.1 mg/L) and aluminum (0.05 to 0.2 mg/L) to
address aesthetic considerations;
• Mandatory health effects language to be used by systems when notifying the
public of violations; and
• State reporting, recordkeeping and primacy requirements.
-------
Implementation Dates
January 1991 Standards for 33 contaminants promulgated
Standards for 5 contaminants reproposed
July 1991
Standards for 5 contaminants promulgated
July 1992
Standards for 33 contaminants effective
State adoption
January 1993 Standards for 5 contaminants effective
Monitoring for 38 contaminants begins
Regulatory Impact
These regulations will reduce the exposure of three million consumers to the
regulated contaminants and result in an estimated reduction of 75 cancer c
per year.
Pesticides are expected to result in most violations, costs and benefits.
Total costs to all public water systems will be approximately $88 million '
State implementation costs will be $21 million initially and $17 million i
years.
Additional monitoring will be required for 200,000 systems.
• 80,000 community and nontransient noncommunity systems ir.
for all contaminants.
• 120,000 transient noncommunity systems must monitor for n
nitrite.
* Monitoring requirements will be standardized to 3/6V9 year r
• Monitoring costs will generally be less than $10 per househr
• It will cost $24 million per year for systems to monitor.
• Monitoring for the 30 unregulated contaminants (contami
be regulated in future rulemakings) will cost systems an .
million.
Approximately 3300 T three percent of all public water system
to provide treatment or find an alternate source of water.
• Treatment will cost $10 to $800 per household depend
•axe, degree of contamination, and other factors.
• It will cost systems $64 million to provide treatment
• Exemptions will be allowed for small systems based
-------
• 1 "***'
• 1 "- j Phase II National Primary Drinking Water Regulations
PHatt U Fact SHftt— ,
Contaminants
Inorganics
Asbestos
Barium1
Cadmium
,
Chromium
Mercury
Nitrate
Nitrite
Total Nitrate/Nitrite
Selenium
Drinking Water
Health Effects
benign tumors
circulatory system
kidney
liver/kidney.
skin, and
digestive system
kidney, nervous
system
melrtemogtoMnernia
•blue-baby syndrome"
melhemogtobinemia
•blue-baby syndrome*
nervous system
EPA Standards (mg/L)'
Final Final Current
MCLG MCL MCL
7 MFL • 7 MFL ' -
2 2 1
0.005 0005 0.01
01 0.1 005
0.002 0002 0002
10 10 10
1 1
10 10
005 005 001
Sources
natural mineral deposits;
also in Asbestos/Cement (A/C) pipe
nalura1 mineral deposits; oil/gas drilling
operations; paint & other industrial uses
natural mineral deposits; metal finishing;
corrosion product in plumbing
natural mineral deposits; metal finishing.
textile, tanning and leather industries
industrial/chemical manufacturing.
fungicide; natural mineral deposits
fertilizers, feedtols. sewage;
naturally in soil, mineral deposits
unstable, rapidly converted to nitrate;
prohibited in working metal fluids
natural mineral deposits; by product ol
copper mining/smelting
Analytic
Method DAT
TEM C/F; DF
DMF;CC
GFAA; ICP; IE; LS;
DAAA RO; ED
GFAA; ICP C/F; LS;
RO;IE
1
GFAA; ICP C/F; LS
RO. IE
MCV; ACV GAC; LS;
C/F; RO
MCR; AHR; IE; RO;
ACR; ISE; 1C EDR
ACR; MCH; IE. RO
IC;SP
GHAA; GFAA EDH.C/F
AA;I.S;RO
1 Find MCLGs and MCL* become effective July 1992 Altai »me. Ihoourronl MCLscoase to b« effective
• MFL •= milhon fibers per liter, with hbet tengt> >IO micron*
' Levels tor banum. aktcarb. akftcarb fuHone. akftcarb suttoiido and pontacMorophonol are proposed Final levels wiR bw usI.ibhsbiNl hy .Inly ITI 1
-------
•to Phase II National Primary Drinking Water Regulations I
'
Phut 11 Fact Sfiett—
Contaminants
Volatile Organic*
o Dichtorobenzene
cis 1.2 Dichtoroethytene
trans-1 ,2-DJchtoroelhylene
1 ,2 Dichtoropropane
Elhylbenzene
Monochtorobenzene
Styrene
Tetrachtoroethylene
Toluene
Xylenes
Drinking Water
Health Effects
nervous syslem.lung.
liver, kidney
nervous system, liver,
circulatory
nervous system, liver.
circulatory
probable cancer, liver,
kings, kidney
kidney, liver, nervous
system
kidney, liver, nervous
system
liver, nervous system
probable cancer
kidney, nervous
system, king
liver, kidney.
nervous system
' Final MCLGs and MCLs become effective July 1992 Al fiat time.
EPA Standards (mg/L)'
Final Final Current
MCLG MCL MCL
06 06
007 007
0.1 0.1
0 0005
07 0.7
0.1 0.1
0.1 0.1
0 0005
1 1
10 10
the current MCLs cease to be effective
Analytic
Sources Method BAT
industrial solvent; chemical AIIVOCS: All VOCs:
manufacturing 5021 GAC/PTA
5022
industrial extraction solvent 503 1
524.1
5242
industrial extraction solvent
soil fumigant; industrial solvent
present in gasoline A insecticides;
chemical manufacturing
pesticide manufacturing; metal
cleaner; industrial solvent
plastic manufacturing; resins used
in water treatment equipment
dry cleaning/industrial solvent
chemical manufacturing; gasoline additive;
industrial solvent
paint/ink solvent, gasoline refining j
by product; component ol detergents !
i
-------
•1 " Phase II National Primary Drinking Water Regulations
r
fc:
1
Contaminants
Pesticides and PCBs
Alachtor
(Lasso)
Aldicarb*
(Tern*)
Aldicarb suNone*
Aldicarb suRoxide*
Airazine
(Alranex. Crisazina)
Carbofuran
(Furadan 4F)
Chtordane
Dtoromochtoropropane
(DBCP. Nemafume)
2.4 D
(Formula 40. Weedar 64)
Elhytene dixomide
(EDB. Bromofume)
Heptachtor
(H 34. Heptox)
Heptachlor
epoxide
Drinking Water
HeallhEHeds
probable cancer
nervous system
nervous system
nervous system
reproductive and
cardiac
nervous system
and reproductive
probable cancer
probable cancer
liver, kidney.
nervous system
probable cancer
probable cancer
probable cancer
EPA
Final
MCLG
0
0001
0002
0001
0.003
0.04
0
0
0.07
0
0
0
Standards (mg/L)1
Final Current
MCL MCL
0002
0003
0003
0003
0003
004
0002
00002
007 01
000005 -
00004
00002
Sources
herbicide on com and soybeans;
under review for cancellation
insecticide on cotton, potatoes, restricted
in many areas due lo gw contamination
degraded from aldicarb by plants
degraded from aldicarb by plants
widely used herbicide on corn and on
non-crop land
soil tumigant/insecticide on com/cotton;
restricted in some areas
soil insecticide for termite control on corn.
potatoes; most uses cancelled in 1980
soil fumigant on soybeans, cotton;
cancelled in 1977
herbicide for wheat, corn, rangelands
gasoline additive, soil fumigant; solvent;
cancelled in 1984; limited uses continue
insecticide on corn; cancelled in 1983 lor .
all but termite control
soil & water organisms convert
heplachtor to the epoxide
Analytic
Method
505, 507
525
531 1
531 1
531 1
505. 507
525
531 1
505. 508.
525
504
515 1
504
505. 508.
525
505. 508.
SL'5
BAT
GAC
GAC
GAC
GAC
GAC
GAC
GAC
GAC/PTA
GAC
GAC/PTA
GAC .
GAC
MlFinal MCLGs and MCU become effective July 1992 At that time, the current MC^feise to he effective
levels lot fouium. alrlic.iili .ilcli, .ill ultono. akhrarh sulloiiclii ;irvl |>«>nl.ir M
pm|io<.i- i.M.il.lr.l,.-d \>y .Inly I I'l'H
-------
II Phase II National Primary Drinking Water Regulations 1
Pka* U Fact Skett— €
EPA Standards (mg/L)'
Drinking Water Final Final Current
Contaminants Health Effects MCLG MCL MCL Sources
Pesticides and PCBs (cont'd)
Lindane nervous system. 0 0002 0 0002 0 004 insecticide lor seed, lumber, livestock;
liver, kidney pest control; most uses restricted in 1983
Melhoxychlor nervous system, 0.04 0.04 0.1 insecticide on alfalfa, livestock
(DMDT, Martale) liver, kidney.
Polychtorinated probable cancer 0 00005 - electrical transformers, plaslicizers;
jphenyte (PCBs. Aroctor) banned in 1979
Pemachtorophenol1 probable cancer. 0 0.001 - wood preservative & herbicide, non wood
liver, kidney uses banned in 1987
Toxaphene probable cancer 0 0.003 0.005 insecticide/herbicide lor cotton, soybeans;
cancelled in 1982
2.4,5-TP nervous system. 0.05 0.05 0 01 herbicide on rangelands. sugarcane, golf
(SHvex) liver, kidney courses Cancelled in 1983
Treatment Techniques
Acrylamide probable cancer, 0 0.005% dosed flocculenis in sewage/
nervous system at 1 mg/L waslewater treatment
Epfchtorohydrin probable cancer. 0 001% dosed epoxy resins A coalings.
liver, kidney, lungs al 20 mg/L Itocculents used in treatment
Analytical Methods Key: Best Available Technolo
TFU • Tramftftuctann Fbhrtmn lAkrrncr^wm AC1V • AuanmntnH Pntrl Vannr I*5F -, Inn ^Alnrliun rinrtrnrln AA • Arhvnhin* Ahimini
GFAA c Graphite Fumac* Atomic Absorption GHAA = Gaseous Hydndo Atomic Absorption 1C = Ion Chromatography Cif = Coagtilahon/Filtration
OAAA « Dvact Atpiraton Atomic Absorpton MCO - Manual Cadmium Reduction SP = Spectrophoiomatric DF = DHUCI Miration
ICP » Induclrvely Coupled Plasma ACR » Automated Cadmium Reduction OMF - OMtomitii Filnaiion
MCV - Manual CoM Vapor AHR . Automated Hydrwmo Reduction E OR - ElocOodlnlysis IUivors.il
' 1 nviHs lor hiirmin aMicnrb, .ilrhr.nrh MillorHi iiblicnrb sulloxicti ami IMIIII.T lilotofiliiriiul ,»« P»O|IO^
-------
Compliance Monitoring
Requirements
Contaminant
Base Requirement
Ground water
Surface water
Trigger that
Increases
Monitoring
Waivers
5 Inorganics
1 Sample every
3 years
Annual sample
MO-
VES
Based on analytical
results of 3 rounds
Asbestos
1 Sample every 9 years
> MO-
VES
Based on VA1
Nitrate
Annual I Quarterly
After 1 year < 50% of MCL, SWS
may reduce to an annual sample
£50% MO-
Nitrite
1 Sample/If < 50% of MO-,
state discretion
50% MO-
18VOQ
Quarterly for one year
Annual after 1 year of no detects
2 0.0005 mg/L
YES
Based on VA'
17 Pesticides
andPCBs
4 Quarterly samples every 3 years
After 1 round of no detects: systems
>3300 reduce to I samples per year
every 3 years; systems £ 3300
reduce to 1 sample every 3 years
Detection
YES
Based on VA1
Unregulated
- 6 IOCS
- 24 SOCs
1 Sample
4 Consecutive quarterly samples
N.A.
YES
Based on VA1
1 VA = Vulnerability Assessment
Ptuut II Fact SHftt—7
-------
Regulatory Development
• Proposed MCLGs, proposed MCLs and treatment techniques - May 22.1959
(54 FR 22062)
• Final MCLGs, MCLs, and treatment technique requirements for 33 contam-
nants • January 30,1991 (56 £B 3526)
• Proposed MCLGs and MCLs for five contaminants - Januarv 30,1991 < 56 £B
3600)
For More Information
EPA Regional Offices
EPA Region 1
Water Supply Branch
JFK Federal Building
Boston. MA 02203
(617) 565-3655
Connecticut, Massachusetts,
Maine, New Hamshire, Rhode
Island, Vermont
EPA Region 2
Water Supply Branch
2G Federal Plaza
New York, NY 10278
(212)264.1800
New Jersey, New York, Puerto
Rico, Virgin Islands
EPA Region 5
Water Supply Branch
230 South Dearborn Street
Chicago, IL 60604
(312) 353-2151
Illinois, Indiana. Michigan,
Minnesota, Ohio, Wisconsin
EPA Region 6
Water Supply Branch
1201 Dm Street
Dallas, TX 75270
(214) 655-7155
Arkansas, Louisiana. New
Mexico, Oklahoma. Te.
EPA Region 3
Water Supply Branch
841 Chestnut Street
Philadelphia, PA 19107
(215) 597-8227
EPA Region 7
^ Water-supply Branch
~~~726"SEnne«ota~Avenue
Kansas City, KS 66101
(913) 551-7032
Delaware, Maryland,
Pennsylvania, Virginia, West
Virginia, District of Columbia
EPA Region 4
Water Supply Branch
345 Courtland Street N.E.
Atlanta, GA 30365
(404)347-2913
Alabama, Florida, Georgia,
Kentucky, Mississippi, North
Carolina, South Carolina,
Ten
Iowa, Kansas, Missouri,
Nebraska
EPA Region 8
Water Supply Branch
One Denver Place
999 18th Street. Suite 1300
Denver. CO 80202-2413
(303)293-1413
Colorado. Montana. Sorth
Dakota. South Dakota. L'tah.
Wyoming
EPA Region 9
Water Supply Branch
75 Hawthorne Street
San Francisco, CA 94105
(415) 744-2250
Arizona, California. Hawaii.
Nevada. American Samoa.
Guam, Trust Territories of
the Pacific
EPA Region 10
Water Supply Branch
1200 Sixth Avenue
Seattle. WA 98101
(206) 553-4092
Alaska. Idaho, Oregon,
Washington
EPA Safe Drinking Water Hotline
© 1.800426-4791
Phase 11 Fact theet—a
-------
Appendices
• Standardized Monitoring Framework
• Asbestos
• Nitrate
• Nitrite
• Inorganics
• Volatile Organic Chemicals
• Pesticides
• Unregulated Contaminants
-------
Standardized
Monitoring
Framework
Compliance Cycle 1
• Period 1
(J993, 1994, 1995)
• Period 2
(1996, 1997, 1998)
• Period 3
(1999. 2000. 2001)
Compliance Cycle 2
• Period 1
(2002, 2003, 2004)
l>to 2010
i-act bneet on Standardized
Monitoring Framework
EPA Phase II Monitoring Series (1 of 8)
April 1991
This fact sheet summarizes the U.S. Environmental Protection Agency's (EPA) Standard-
ized Monitoring Framework as promulgated under the Agency's Phase // Rule on Januar\-
30.1991.
Purpose
The primary objective of the Standardized Monitoring Framework is to reduce the
variability and complexity of drinking water monitoring requirements. The
objective is achieved through the standardization of monitoring requirements and
the synchronization of monitoring schedules across "rules" or by contaminant
group.
Applicability
The Standardized Monitoring Framework currently applies to the 38 contami-
nants contained in EPA's Phase II Rule. However, the Framework was designed
to apply to all source-related contaminants, including volatile organic chemicals,
pesticides, inorganic chemicals, and radionuclides. Subsequent rulings by EPA for
such contaminants will, in general, contain monitoring requirements that Tit" or
fall within the Standardized Monitoring Framework. In general, the Standardized
Monitoring Framework applies to all community water systems and all
nontransient noncommunity water systems. For some contaminants (i.e.. nitrate
and nitrite), the Standardized Monitoring Framework also applies to transient
noncommunity water systems.
The Framework
For the purpose of standardizing monitoring requirements across rules or by
contaminant group, EPA has established a nine-year (based on a calendar year;
compliance 'cycle," with the first cycle beginning on January 1,1993. The nine-
year compliance cycle contains three three-year compliance "periods." The
first three-year compliance period extends from 1993 to 1995, the second period
from 1996 to 1998, and the third from 1999 to 2001. The second nine-year compli-
ance cycle begins in 2002 and extends through 2010.
The Standardized Monitoring Framework encompasses both sampling and vulner-
ability assessments. The Framework provides states with the flexibility to deter-
mine at which point in a compliance period systems must conduct sampling
activities. For example, states may wish to prioritize sampling based on system
size, vulnerability, lab capacity, and coirmunity/nontransient noncommunity
criteria. Once a system is scheduled to sample within a particular three-year
compliance period (e.g., the second year in the compliance period), the system
must then sample in the same year in subsequent compliance periods (e.g., the
second year).
Initial sampling for contaminants under EPA's Phase II Rule begins in the three-
year compliance period starting January 1,1993. Repeat sampling for applicable
systems is to take place during the compliance periods 1996 to 1998 and 1999 to
Standafdittd Monitoring Framework—;
-------
2001. For subsequent rulings by the Agency, the initial sampling period for
contaminants will be during the first full three-year compliance period following
the effective date of the ruling (i.e., 18 months after the date of promulgation;. For
example, if Phase V is promulgated in March 1992, the effective date of the ruling
would be September 1993 (the middle of a compliance period). The irutia. rsund of
sampling for Phase V contaminants would then take place during the 19*o to
1998 compliance period.
Specific Standardized Monitoring Requirements
(To learn how these requirements are applied to the 38 contaminants in the Phase
11 Rule, consult Fact Sheets 2 through 8 ofEPA's Monitoring Seriesr.
• All systems must sample at a base (or minimum) sampling frequency which is
specified by EPA for each contaminant or group of contaminants unless a
waiver has been granted by the state (see waiver section below).
• Initial base sampling requirements are the same for all systems regardless of
system size or water source. (This requirement does not apply to the inorganic
contaminants contained in the Phase n Rule.)
• Repeat base sampling requirements are generally the same for all systems
regardless of system size anc water source. (Exceptions to this rule exist for
pesticides.) Generally, repeat base sampling requirements are reduced after
the successful conduct of initial sampling.
• All systems which "detect" a contaminant must conduct quarterly sampling
until the state determines that the analytical results are "reliably and consis-
tently" below the maxuaum contaminant level (MCL). Detection is defined
separately for each contaminant or group of contaminants at either the MCL or
at the analytical method detection limit (MDL). Groundwater systems must
take a minimum of two quarterly samples and surface water systems must
take a minimum of four quarterly samples before the state can determine that
the analytical result* are "reliably and consistently" below the MCL.
• "Reliably and consistently* below the MCL means that though a system dl
contaminants in its water supply, it has sufficient knowledge of the source or
extent of the contamination to predict that the MCL would not be exceeded.
Wide variations in the analytical results near the MCL would not meet the
"reliably and consistently" test
Grandfathering of Data
• Sampling data collected three yean prior to the beginning of an initial three-
year compliance period may be used to satisfy a system's initial sampling
requirements. Such "grandfathering of data" would enable an eligible system to
sample at repeat frequencies which are generally lower than initial
frequencies.
• Vulnerability assessments may not be grandfatheTed.
Waivers
• Waivers to sampling requirements are available to all systems and are based
upon a vulnerability assessment and/or the consideration of prior analytical
results.
• Waiver determinations are to be made by the state and are to be made on a
i»nntjiminynt.hyw»ftntJimin«nt basis.
-------
• Vulnerability assessments may be conducted by the state, a system, or a tbrc-
party organization. States are to approve all assessments.
• Systems which do not receive waivers must sample at required base
frequencies.
• There are two basic types of waivers:
1) Waiver by Rule: Systems meet EPA-specified criteria.
2) Waiver by Vulnerability Assessment (two-step process):
Step I—Ute Waiver A determination is made whether a given contami-
nant was used, manufactured, and/or stored in a system area. If the an-
swer to the inquiry is yes or unknown, the system is "susceptible" to
contamination and a "use waiver" can not be granted.
Step 2—Susceptibility Waiver If a "use waiver" can not be granted, a
system may conduct a thorough vulnerability assessment of the water
source to determine the system's "susceptibility" to contamination. Suscep-
tibility is to be based on: a) prior analytical and/or vulnerability assess-
ment results, b) environmental persistence and transport of the contami-
nant, c) how well the source is protected, d) wellhead protection program
reports, and e) elevated nitrate levels.
Systems with no known "susceptibility" to contamination (based upon an
assessment of the above factors), may be granted a "susceptibility waiver."
If "susceptibility" can not be determined, a system is not eligible for a
waiver and must sample at the regulatory minim u-.-n or base sampling
frequency.
Standnrdutd Monitoring Fnmtuork—3
-------
Fact Sheet on Asbestos
EPA Phase II Monitoring Series (2 of 8)
April 1991
This fact sheet summarizes the monitoring requirements for asbestos as promulgated
on January 30, 1991 under the U.S. Environmental Protection Agency's (EPAj Phase
II Rule. These requirements will take effect on July 30, 1992.
jlatcd
Contaminant
Asbestos
MCL
7 Million Fibers/Liter
(MFL>—(greater than
10 microns)
Systems Affected
All community water systems (CWS) and n on transient noncommunity water
systems (NTWS) must comply with the Phase II monitoring requirements for
asbestos.
Sampling Points
1) Sampling must be conducted at each entry point to the distribution system
which is representative of the well or source water after treatment.
2) Systems that are vulrerable to asbestos contamination, either solely due to
corrosion of asbestos
-------
Increased Sampling (if MCL is exceeded)
1) Any systan exceeding the MCL for asbestos must take quarterly samples: in the
quarter Trnmaftiatply following the violation) until a baseline is established imininum of
two quarters for groundwater lysterru and four quarters for turface. water tyttems;
2) If the state determines that the baseline is "reliably and consistently" below
the MCL, the sampling frequency may be reduced to the base requirements.
Compliance Determination
1) If a system samples more frequently than annual (Le.. quarterly), the system would be in
violation if the annual average at any sampling point exceeds the MCL
2) If a system samples on an annual or less frequent bag" the system would be in violation
if one sample (or the average of the initial and confirmation samples) at any point
exceeds the MCL
Confirmation Samples
States may require a confirmation sample for any sample that exceeds the MCL.
These confirmation samples must be taken from the same sampling point and as
soon as possible (within no greater than a two week time period) after the initial
sample. If a confirmation sample is used, the compliance determination is based
on the average of the results of both the confirmation and initial samples.
Public Notice
A system in violation of the National Primary Drinking Water Regulation (i.e.,
MCL, monitoring and reporting requirements, etc.) for asbestos must give public
notice. The public notice must include the specific mandatory health effects
language contained in the Phase II Rule.
Compositing
Composite samples are allowed at state discretion from no more than five sam-
pling points. Compositing of samples must be completed in a certified drinking
water laboratory.
1) For systems serving greater than (>) 3300 persons, compositing is only allowed
at sampling points within a single system.
2) For systems serving less than (S) 3300 persons, compositing among different
systems is permitted.
Waivers
States may grant a waiver if, on the basis of a vulnerability assessment, the
system determines it is not vulnerable to asbestos contamination. The state may
grant a waiver based on consideration of the following factors:
1) Potential asbestos contamination of the water source, and
2) The use of asbestos-cement pipe for finished water distribution and the corro-
sive nature of the water.
If the state grants a waiver, base sampling requirements are eliminated. Waivers
are effective for one three-year compliance period. However, waivers only need to
be renewed in the first compliance period of each nine-year compliance cycle. If
waivers are not renewed, systems must sample according to base requirements.
Atbettot—2
-------
Standardized Monitoring Framework:
Asbestos (CWS and NTWS)
''•••"'••'*;••
o
o
o
2
o
a
b
£
o
£
u.
•DO
8£
w ^
$-
.s >>
C) a*
%%%%!%%%%«
CALENDAR
YEAR
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
• ••' ••, '
,
?
•§
te 'n
11
t
O
II
a-?
®p
o
I?
|
O
r
BASE REQUIREMENTS
'* ^ '";/' '•"*•*'£ ^'', ' rf ' ' '"
"%? '.' '$ • "'%Cvv'- „"£ j&rv »* ' * '"35??^,'" * ""
, , •»""'' >v*'"
.^ JM.^-^ ifiSSft- jJ'*' •y^i^'^it" '
Z£jx%s~: ]^' ''^&'^V'"'Z' •£>&•£<•?••" - '
t
l sample at
each sampling
point
i
1
No Requirements
No Requirements
1
1
t
1 sample at
each sampBng
point
1
WAIVERS
(All SYSTEMS)
, „ * , *., . . .
.' ' * rf " 7 ," ~~1' '
_
- . •', '',' ' • K
Waivers Basea on
VulneraDility
Assessment
(No Samples Required) .
1
1
1
Not Applicable
1
1
1
Not Applicable
1
1
Waivers Based on
Vulnerability
Assessment
1
1
NOTE: States will designate the year during each compliance
period in which each system must monitor.
A»btttot—J
-------
Asbestos Monitoring Flow Chart
Initial Frequency
1993-1995
All CWS and NTWS
(beginning 1993)
YES / Waiver?
(effective 1 period)
No
sampling
while waiver
in effect
Waiver?
(effective 1 period)
Results
>MCL?
Quarterly
sampling
- ''-YES /&*&consistently
»
,,- . .Frequency
-------
Fact Sheet on Nitrate
EPA Phase II Monitoring Series (3 of 8)
April 1991
This fact sheet summarizes the monitoring requirements for nitrate as promulgated
on January 30. 1991 under the U.S. Environmental Protection Agency's (EPAj Phase
II Rule. These requirements will take effect on July 30. 1992.
Regulated
Contaminants
Nitrate
Total Nitrate/Nitrite
MCL (for both)
10 mg/L (as Nitrogen)
Trigger (for both)
5 mg/L (as Nitrogen)
Systems Affected
All community water systems (CWS), transient and nontransient noncommuruty
water systems (TWS and NTWS) must comply with the Phase II monitoring
requirements for nitrate.
Sampling Points
Sampling must be conducted at each entry point to the distribution system.
Sampling points must be representative of the well or source water after
treatment
Initial Base Sampling
Sampling for nitrate is to be conducted by all water systems beginning January 1.
1993. The frequency of initial sampling is as follows:
CWS and NTWS: Groundwater system* must sample annually
while turfaee water system* must sample quarterly.
TWS: Such systems regardless of the water source must sample
annually.
Grandfathering
Not allowed.
Trigger for Increased/Decreased Sampling
Any sample greater than (2) 50 percent of the MCL triggers the need for increased
sampling. Analytical results less thin (<) 50 percent of the MCL for a minimum of
one round of sampling can trigger dec-eased sampling requirements. The trigger
it not applicable to transient noncommunity water system*. (See side bar
for MCL and trigger level for nitrate.)
Repeat Base Sampling (< 50% MCL)
CWS and NTWS: Groundwater system* must continue sampling
on an y*»mii basis as during the initial sampling phase. States may
reduce the sampling frequency to annual for turfaee water system*
provided the analytical results from four consecutive quarters is less
Nitrate—
-------
than (<) 50 percent of the MCL. Repeat samples must be taken
during the quarters) which yielded the highest analytical results
during the initial compliance period.
TWS: Same as initial sampling requirements.
Increased Sampling (> 50% MCL or > MCL)
CWS and NTWS: Systems collecting any sampled) greater than (>)
50 percent of the MCL must increase or continue sampling on a
quarterly basis, regardless of the water source. States have the
discretion to decrease the sampling frequency to annual for ground-
water tyrtemt provided the results of four consecutive quarterly
samples are "reliably and consistently" below the MCL States may
reduce the sampling frequency to annual for surface water tyttetm
provided the analytical results from four consecutive quarters is less
than (<) 50 percent of the MCL
TWS: Same as initial sampling requirements.
Compliance Determination
If any sample exceeds the MCL for nitrate, systems must take a confirmation
sample (see below). The compliance determination is then based on the average of
the results of both the confirmation and initial samples.
Confirmation Samples
Systems must take a confirmation sample within 24 hours after the results of the
initial sample are found to be greater than (2) the MCL. Systems unable to meet
the 24-hour confirmation sampling requirement must issue a public notice to
consumers of the system and must then analyze a confirmation sample within two
weeks of receiving the results of the initial sample.
Public Notice
Any system violating the National Primary Drinking Water Regulation (i.e., MCL.
monitoring and reporting requirements, etc.) for nitrate must give public notice.
The public notice must include the specific mandatory health effects language
contained in the Phase n Rule. The public notice requirements also apply to
systems unable to take confirmation samples within a 24-hour time period (see
confirmation sample section above).
Compositing
Composite samples are allowed at state discretion from na more than five sam-
pling points. Compositing of samples must be completed in a ce-tified drinking
water laboratory.
1) For systems serving greater than (>) 3300 persons, compositing is only allowed
at sampling points within a single system.
2) For systems serving less than (£) 3300 persons, compositing among different
systems is permitted.
Waivers
Not allowed
Nitrate- 2
-------
Nitrate Monitoring Flow Chart
Transient Water
Systems
Surface Water
CWSandNTWS
Groundwater
CWS and NTWS
Begin annual
sampling in
1993
4 quarterly
samples in
1993
Begin annual
sampling in
1993
Initial Frequency
1993-1995
Quarterly
sampling
(except TWS)
*50%MCL?
1 annu
sample during
quarter which
previously
yielded highest
anatytica)
andcorvisiertlydyiCL:
Repeat Frequency
1996-1998,1999-2001, etc.
>— •<»>.•»»••.«»...,.».,
ncreaseo
Frequency
Nitrate ^
-------
Fact Sheet on Nitrite
EPA Phase II Monitoring Series (4 of 8)
April 1991
This fact sheet summarizes the monitoring requirements for nitrite as promulgated on January
30.1991 under the U.S. Environmental Protection Agency's (EPA) Phase II Rule. These
requirements will take effect on July 30,1992.
Systems Affected
All community water systems (CWS), transient and nontransient noncommunity
water systems (TWS and NTWS) must comply with the Phase n monitoring require-
ments for nitrite.
Sampling Points
Sampling must be conducted at each entry point to the distribution system. Sampling
points must be representative of the well or source water after treatment.
Initial Base Sampling
Between 1993 and 1995, all systems must take one sample. The state will designate
the year in which each system samples within this compliance period.
Grandfathering
Not allowed.
Trigger for Increased/Decreased Sampling
the trigger for increased/decreased sampling for nitrite is 50 percent of the MCL
Contain bunt
Regulated Contaminants
Trigger
Nitrite lmg/L (as Nitrogen)
Total Nitrate/Nitrite 10 mg/L (as Nitrogen)
0.5 mg/L (as Nitrogen)
5 mg/L (as Nitrogen)
Repeat Base Sampling (< 50% MCL)
If the results of initial sampling are less than (<) 50 percent of the MCL, repeat
sampling requirements may be reduced at state discretion.
Nitritt—l
-------
Increased Sampling (> 50% MCL or 2 MCL)
1) Systems collecting any samplers) greater than (>) 50 percent of the MCL must
sample quarterly for at least one year.
2) States may decrease the sampling frequency to annual provided the results of four.
consecutive quarterly samples are "reliably and consistently" below the
3) Systems sampling annually must take subsequent samples during the
which previously yielded the highest analytical results).
Compliance Determination
If any sample exceeds the MCL for nitrite, systems must take a confirmation sample
(see below). The compliance determination is then based on the average of the results
of both the confirmation and initial samples.
Confirmation Samples
Systems must take a confirmation sample within 24 hours after the results of the
initial sample are found to be greater than (£) the MCL. Systems unable to meet the
24 hour confirmation sampling requirement must issue a public notice to consumers
of the system and must then analyze a confirmation sample within two weeks of
receiving the results of the initial sample.
Public Notice
Any system violating the National Primary Drinking Water Regulation (i.e.. MCL.
monitoring and reporting requirements, etc.) for nitrite must give public notice. The
public notice must include the specific mandatory health effects language contained in
the Phase n Rule. The public notice requirements also apply to systems unable |
take confirmation samples within a 24 hour time period (see confirmation sampi
section above).
Compositing
Composite samples are allowed at state discretion from no more than five sam-
pling points. Compositing of samples must be completed in a certified drinking
water laboratory.
1) For systems serving greater than (>) 3300 persons, compositing is only allowed
at sampling point* within a tingle system.
2) For systems serving less than (£) 3300 persons, compositing among different
systems is permitted.
Waivers
Not allowed
Nitntf—2
-------
Nitrite Monitoring Flow Chart
All CWS, TWS and
NTWS
1 sample
during initial
period
Initial Frequency
1993-1995
Repeat Frequency
1996-1998,1999-2001, etc.
TWgger for Increased
Frequency
Nitnte—J
-------
Fact Sheet on Inorganics
EPA Phase II Monitoring Series (5 of 8)
April 1991
This foci sheet summarizes the monitoring requirements for five inorganic chemicals (barium.
_»ruum, chromium, mercury, and selenium) as promulgated on January 30.1991 under the
US. Environmental Protection Agency's (EPA) Phase II Rule. These requirements will tote
effect on July 30.1992.
Regulated
Contaminants
MCL
Barium
Cadmium
Chromium
Mercury
Selenium
2
0.005
0.1
0.002
0.05
Systems Affected
All community water systems (CWS) and nontransient noncommunity water systems
(NTWS) must comply with the Phase n monitoring requirements for barium, cad-
mium, chromium, mercury, and selenium.
Sampling Points
Sampling must be conduct'*! at each entry point to the distribution system. Sampling
pointa must be representative of the well or source water after treatment
Initial Base Sampling
Groundwater system* must take one sample during the compliance period
1995. The state will designate the year in which each system must sample wi
compliance period. Surface water system* must sample annually beginning in
Waivers from sampling may be granted by the state (see below for a summary of
waiver requirements).
Grandfathering
States may allow previous sampling data to satisfy the initial base sampling require-
ments, provided at least one sample was taken after January 1,1990.
Repeat Base Sampling
Repeat base sampling requirements are the same as those for the initial base phase
unless a waiver has beta granted by the state (Le., one sample per three-year compli-
ance period for grovndwater and one sample each year for twfttce water tyttenu >
Trigger for Increased Sampling
The maximum contaminant level (MCL) for each inorganic chemical triggers the
requirement for increased sampling (see side bar text for list of contaminants and
their corresponding MCLs).
Inorganic*
-------
Increased Sampling
1) Any system exceeding the MCL for a given contaminant must take quarterly
samples (in the quarter immediately following the violation) until a baseline is
established (minimum of two quarters for groundwater tyttemt and four quar-
ters for turface water tyttemt).
2) If the state determines that the baseline is "reliably and consistently* below the
MCL, the sampling frequency may be reduced to the base requirements.
Compliance Determination
1) If a system samples more frequently than annual (i.e., quarterly), the system
would be in violation if the running annual average at any sampling point exceeds
the MCL
2) If a system conducts sampling on an annual or less frequent basis, the system
would be in violation if one sample (or the average of the initial and confirmation
samples) at any point exceeds the MCL
Confirmation Samples
States may require a confirmation sample for any sample that exceeds the MCL
These confirmation samples must be taken from the same sampling point and as soon
as possible (within no greater than a two week time period) after the initial sample. Lf
a confirmation sample is used, the compliance determination is based on the average
of the results of both the confirmation sample and the initial sample.
Public Notice
Any system violating the National Primary Drinking Water Regulation (i.e., MCL,
monitoring and reporting requirements, etc.) for one or more of the five inorganic
chemicals must give public notice. Hie public notice must include the specific manda-
tory health effects language contained in the Phase U Rule.
Compositing
Composite samples are allowed at state discretion from no more than five sampling
points. Compositing of samples must be completed in a certified drinking water
laboratory.
1) For systems serving greater than (>) 3300 persons, compositing is only allowed at
sampling points within a single system.
2) For systems serving less than (£) 3300 persons, compositing among different
systems is permitted
Waivers
States may grant "waivers by rule" to systems of up to nine years (or one compliance
cycle) for each of the five inorganic contaminants. In order to qualify for a waiver, a
system must have three previous compliance samples (including one taken after
January 1,1990), and all previous analytical results must be below the MCL (see
grandfathehng section above). The waiver must be granted at the beginning of the
year in which the system is scheduled to sample, otherwise the system is subject to
base sampling requirements. Systems must take at least one sample during the nine-
year waiver period.
Inorgaiuci—2
-------
The state must consider a variety of issues in making the "waiver by rule" determina-
tion, such as:
1) reported concentrations from all previous monitoring,
2) degree of variation in reported concentrations, and
3) other factors which may affect contaminant concentrations (i.e., groundwater
pumping rates, changes in the system's configuration, changes in the system's,
operating procedures, or changes in stream flows or characteristics).
-------
vionitonng Framework:
Inorganics (CWS and NTWS)
First 9 - year Compliance Cycle
f Begins Second
j 9 - year Cycle
A
CALENDAR
YEAR
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
'
Initial Monitoring
Round
Repeat
Monitoring
(Repeat
Monitoring
B a
BASE REQUIREMENTS
SW
-
1 sample at
each sampling
point
] sample at
each sampling
point
1 sample at
each sampling
point
1 sample or
each sampling
point
1 sample at
each sampling
point
1 sample at
each sampling
point
1 sample at
each sampling
point
1 sample at
each sampling
point
1 sample at
each sampling
point
1 sample at
each sampling
pojnt
Itamptoat
•ach wmpling
point
1 sample at
each sampling
point
GW
'
f
\
1 sample at
eacn sampling
point
1
f
1 sample at
each sampling
point
I
f
1 sample at
each sampling
point
1 sample at
each sampling
point
\
WAIVERS
(ALL SYSTEMS)
State may waive the Base
monironng reouirenienrs
after 3 samples of less tr*an
the MCI ore taken
4
1 sarr
each sc
PC
J
1
k
pie at
jmpling
>int
-
I
•
NOTE: States will designate the year during each compliance
period in which each system must monitor.
-------
Inorganics Monitoring Flow Chart
Initial Frequency
1993-1995
AIICWSandNTWS
(beginning 1993)
3 rounds
of previous
data MCL?
Repeat Frequency
1996-1998,1999-2001, etc.
Trigger for Increased Frequency
^^" jCfj^..£.^*j.-jZrl-.f . ' t ....
Inorganic*—5
-------
i-act Sheet on Volatile
Organic Chemicals
EPA Phase II Monitoring Series (6 of 8)
April 1991
This fact sheet summarizes the monitoring requirements for 10 new volatile organic chemicals
(VOCsj as promulgated on January 30.1991 under the U.S. Environmental Protection
Agency's (EPA) Phase 11 Rule and will appfy everuualry to the 8 VOCs currently regulated The
monitoring requirements will take effect for all 18 VOCs on July 30.1992
Regulated
Contaminants
Bght Original VOCs (mg/L)
Benzene 0.005
Canon tetrachloride 0.005
1,2-Dichloroethane 0.005
1,1-Dichloroediylene 0.007
para-Dichlorobenzene 0.075
1,1,1-Trichloroethane 020
Trichloraethylene 0.005
Vinyl chloride 0.002
TtnNtwVOCs MCL(mo/U
os-l,2-Dichloroethylene 0.07
1,2-Dichloropropane 0.005
Ethylbenzene
Monochlorobenzene
o-Dichlorobenzene
Stymie
Tetnchloroethyiene
Toluene
trans-1.2-
Dichlarcethylene
Xylenes (total)
NOTE: The method detection
limit (MDL) for all 18 volttile
orguia u 0.0006 rayfi.
0.7
0.1
0.6
0.1
0.005
1
0.1
10
Systems Affected
All community water systems (CWS) and nontransient noncommunity water systems
(NTWS) must comply with the Phase n monitoring requirements for volatile organic
chemicals.
Sampling Points
Sampling must be conducted at each entry point to the distribution system. Sampling
points must be representative of the well or source water after treatment If condi-
tions warrant, the state may designate additional sampling points within the distri-
bution system or at consumer taps which, more accurately determine consumer
exposure.
Initial Base Sampling
Between 1993 and 1995, all systems must take four consecutive quarterly samples for
each of the new contaminants, unless (a) a waiver has been granted by the state (see
waiver requirements below) or (b) the system has previous sampling data that
qualifies it for reduced sampling (see grandfathering section below). The state will
designate the year in which each system samples within this compliance period.
Grandfathering
States may allow sampling data collected after January 1,1988 to satisfy the initial
base sampling requirements. If the initial samples for the new organics are completed
by December 31,1992 and the system did not detect any of the organics, then the
system shall take one sample annually beginning January 1,1993.
Trigger for Increased/Decreased Sampling
The method detection limit (MDL) is the trigger for increased/decreased sampling for
each of the volatile organics. [See side bar for a list of contaminants and their corre-
sponding maximum contaminant levels (MCLs) and MDLs].
Repeat Base Sampling (no detects)
Systems would continue taking four consecutive quarterly samples during subsequent
three-year compliance periods. However, if contaminants are not detected during the
Voiatdt Orforue Ch*rruaaLi—l
-------
initial round of sampling, then systems could decrease their sampling frequency
beginning in the 1996 compliance period as follows:
1) Groundwater systems would take one sample annually. After three years of
annual sampling and no previous detection, groundwater tyttemt could reduce
their sampling frequency to one sample per compliance period.
2) Surface water tyttemt must sample annually.
Increased Sampling (if detected or MCL exceeded)
If contaminants are detected at the MDL or if the MCL is exceeded, then systems
must sample quarterly beginning in the next quarter.
1) Systems remain on quarterly sampling until a baseline is established (minimum
of two quarters for groundwater tyrtemt and four quarters for turface water
tyttemt).
2) If the baseline indicates a system is "reliably and consistently" below the MCL. the
state may reduce the system's sampling frequency to annual. (Annual sampling
must be conducted during the quarter which previously yielded the highest
analytical result)
3) Systems which have three consecutive annual samples with no detection may
apply to the state for a waiver (see waiver requirements below).
4) If any detection exceeds the MCL, both groundwater and turface water ty+
term must take four consecutive quarterly samples until a reliable baseline is
established.
Compliance Determination
1) If a system samples more frequently than annually (quarterly or semi-annually),
the system is in violation if the annual average at any sampling point exceeds jhe
MCL
2) If a system samples on an annual or less frequent basis, the system would be in
violation if one sample (or the average of the original and confirmation samples) at
any point exceeds the MCL
Confirmation Samples
States may require a confirmation sample for positive or negative results. If taken,
the compliance determination must be based on the average of the results of both the
confirmation sample and the *p»***i sample.
Public Notice
Any system violating any National Primary Drinking Water Regulation (MCL
monitoring and reporting requirements, etc.) for one or more of the VOCs must give
public notice. Tne public notice must include the specific mandatory health effects
language for each of the new VOCs contained in the Phase H Rule.
Compositing
Composite samples are allowed at state discretion from no more than five sampling
points. Compositing of samples must be completed in a certified drinking water
laboratory.
Organic Chemical* 2
-------
»; ror s>s';ems serving greater than 01 3300 persons, composiung ;s only allowed a:
sampling points within a single system.
2) For systems serving less than (<) 3300 persons, compositing among different
systems is permitted.
Waivers
•Systems can apply to the state for a waiver from initial and repeat base sampling
frequencies. Systems are eligible for both "use" and "tutceptibility" waivers provided
the system has conducted a vulnerability assessment Systems are eligible for waivers
beginning in the compliance period 1993 to 1995. Waivers are effective for one compli-
ance period: they must be renewed in subsequent compliance periods or the system
must conduct sampling that is commensurate with base requirements.
Use Waivers
When a system, on the basis of a vulnerability assessment, can demonstrate that
volatile organics were not used previously in the water supply area (i.e., the contami-
nant was not used, manufactured, stored or disposed), the system can apply to the
state for a "use" waiver. If a waiver is granted, sampling requirements are eliminated.
Systems ineligible for a "use" waiver can apply for a waiver based on "susceptibility."
Susceptibility Waivers
"Susceptibility" waivers are contingent on the conduct of a thorough vulnerability
assessment, which considers evaluation of prior analytical and/or vulnerability
assessment results (including those of surrounding systems), environmental persis-
tence and transport, how weU the source is protected, Wellhead Protection Assess-
ments, and proximity to sources of contamination. If a waiver is granted based on
susceptibility, sampling requirements are »lJTnmat*H for that compliance period.
Sampling Frequency with Waivers
Croundwater tyttemt that have been granted a waiver are required to sample once
every six years and must update the vulnerability assessment at the midpoint or
three year mark of the period. Surface water tyttenu with a waiver are required to
sample only at the discretion of the state.
Volatile Organic Cfiemimit—3
-------
Standardized Monitoring Framework:
Volatile Organic Chemicals (CWS and NTWS)
First 9 - year Compliance Cycle
I Begins Second 1
r 9-yecrCycle
CALENDAR
YEAR
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
•
,
f "°
1S
?
Repeat
Monitoring
11
I
!
BASE REQUIREMENTS:
ALL SYSTEMS
-
- , •• • , • -,
•A Quarterly
samples at each
sampling point
4 quarterty
samples at each
sampling point
4 quarterly
samples at each
sampling point
4 quarterly
samples at each
sampling point
REDUCED MONITORING:1
SW GW
•*"'", •' '
-
't ' . t ';~X «.-»*
« ' ' : • ,
'' ^ !," . '.,.,,
\ sample at 1 sample at
each sampling each sampling
point. point.
it ti
ti *i
__ t
1 2
1 sample
1 sample
- I
• t
1
» 1 sample
1
1
WAIVERS '
SW » G'.V
• *
: *
t ! '
State *
I1
T r
State J
discref ton »
IH
t!1
State >
discretion J
t r »
X
State |
dbcretton,
Ih
i
1
ipie
r
'
pie
r
1: Provided initial monitoring completed by 12/31/92
and the system had no detection.
2: Reduction atowed after no detection In three years
of annual monitoring.
NOTE:
States wll designate the year
during eocn compliance period
m v»*teh each system must monitor
Volatile Organic Cticmtcau—
-------
Volatile Organic Chemicals Monitoring
Flow Chart
Initial Frequency
AIICWSandNTWS
(beginning 1993)
revious
data collected
after 1988 with no
detections?
consecutive
quarterly
samples
1993-95
sample
per year
1993-95
Quarterly
sampling at
affected
points
SW: Stale dscretbn
GW: 1 sample per
6 year
VA update
If
>MCL
min. of
4qtrsrel
andconsts
tentty
-------
Fact Sheet on Pesticides
EPA Phase II Monitoring Series (7 of 8)
April 1991
This fact sheet summarizes the monitoring requirements for 17 pesticides and
polychlonnated biphenyls (PCBs) as promulgated on January 30, 1991 under the
U.S. Environmental Protection Agency's (EPA) Phase II Rule. These requirements
will take effect on July 30,1992.
Systems Affected
All community water systems (CWS) and nontransient noncommunity water systems
CNTWS) must comply with the Phase n monitoring requirements for pesticides ar.d
PCBs.
Sampling Points
Sampling must be conducted at each entry point to the distribution system. Sampling
points must be representative of the well or source water after treatment.
Initial Base Sampling
Between 1993 and 1995, all systems must take an initial round of four consecutive
quarterly samples unless a waiver has been granted by the state (see below for
summary of wa.ver requirements). The state will designate the year in which each.
system samples within this compliance period.
Grand fathering
States may allow sampling data collected after January 1,1990 to satisfy the initial
base sampling requirements.
Trigger for Increased/Decreased Sampling
The method detection limit (MDL) is the trigger for increased/decreased sampling for
each pesticide or PCB [see table on following page for a list of contaminants and their
tn«Tmiiim contaminant levels (MCLs) and MDLs].
Repeat Base Sampling (no detects)
If contaminants are not detected during the initial sampling phase, systems may
decrease their sampling frequency beginning in the 1996 compliance period.
1) Systems that serve greater than (>) 3300 persons may reduce their sampling
frequencies to two samples in one year per compliance period.
2) Systems that serve less than (3 3300 persons may reduce their sampling frequen-
cies to one sample in each compliance period.
Pei
-------
Regulated Contaminants
Contaminant
AJachlor
Aldicarii
AJdicarfc sulfoxide
AJdicart) sulfone
Atrazine
Carbofuran
Chlordaoe
Dibromochloropropane (DPCP)
2,4-D
Ethylene dibromide (EDB)
Heptachlor
Heptachlor eporide
Linda oe
Methoxychlor
Polychlorinated biphenyls (PCB«)
Pentachlorophenal
Toxapheoe
2.4,5-TP (SUvex)
MCU (mgA)
MDL' (mgl)
0.002
0.003*
0.003*
0.003*
0.003
0.04
0.002
0.0002
0.07
0.00005
0.0004
0.0002
0.0002
0.04
0.0005
0.001
0.003
0.05
0.0002
0.0005
0.0005
00006
0.0001
o.ooos
00002
0.00002
0.0001
0.00001
0.00004
0.00002
00000-2
0.0001
00001
000004
0001
0.0002
'MCL*M«Jomum Coaunuouu Level
•MDUMethod Detection Limit
"MCL* for aJdiart. aldiait Mlforide, aJditmrb fulfooe wen rcpnposed under the Ph*»e n Rule. 6oa! leveij «nil
be promulgated by July 1.1991.
Increased Sampling (if detected or MCL exceeded)
If contaminants are detected or if the MCL is exceeded in any sample, then systems
must sample quarterly beginning in the next quarter. Systems are to sample quar-
terly until a baseline is established (minimum of two quarters for groundvater
tyttemt and four quarters for turfact voter tyttenu).
1) If the baseline indicates a system is "reliably and consistently" below the MCL. the
state may reduce the system's sampling frequency to annual. (Annual sampling
must be conducted during the quarter which previously yielded the highest
analytical result)
2) Systems which have three consecutive annual samples with no detection can
apply to the state for a waiver.
Compliance Determination
1) If a system samples more frequently than annual (Le., quarterly or semi-
annually), the system would be in violation if the running annual average at any
sampling point exceeds the MCL
2) If a system conducts sampling on an annual or less frequent basis, the system
would be in violation if one sample (or the average of the initial and confirmation
samples) at any point exceeds the MCL
Confirmation Samples
States may require a confirmation sample for positive or negative results. If a confir-
mation sample is used, the compliance determination is based on the average of the
results of both the confirmation sample and the initial sample.
-------
Public Notice
Any system violating a National Primary Drinking Water Regulation (i.e.. MCL.
monitoring and reporting requirements, etc.) for one or more of the 17 pest:ndes and
PCBs must give public notice. The public notice must include the specific n-.andatory
health effects language contained in the Phase n Rule.
Compositing
Composite samples are allowed at state discretion from no more than five sampling
points. Compositing of samples must be completed in a certified drinking water
laboratory.
1) For systems serving greater than (>) 3300 persons, compositing is only allowed at
sampling points within a single system.
2) For systems serving less than (<) 3300 persons, compositing among different
systems is permitted
Waivers
Systems can apply to the state for a waiver from initial and repeat base sampling
frequencies. Systems are eligible for both "me" and "tuiceptibility* waivers pro-
vided the system has conducted a vulnerability assessment Systems are eligible for
waivers beginning in the compliance period 1993 to 1995. Waivers are effective for
on? compliance period: they must be renewed in subsequent compliance periods or the
system must conduct sampling that is commensurate with base requirements.
Use Waivers
When a system, on the basis of a vulnerability assessment demonstrates that the
regulated pesticide/PCB has not been used in the water supply area (i.e., the con
nant was not used, manufactured, stored or disposed of in the area), the system
apply to the state for a "use" waiver. Systems not eligible for "use" waivers may
qualify for a waiver by evaluating susceptibility (see below).
itarni-
^m
Susceptibility Waivers
"Susceptibility" waivers are contingent on the conduct of a thorough vulnerability
assessment Such a vulnerability assessment must consider prior analytical and/or
vulnerability assessment results (including those of surrounding systems),
environmental persistence and transport, how well the source is protected. Wellhead
Protection Assessments, and proximity of the supply to sources of contamination.
PtltlCl
-------
Standardized Monitoring Framework:
Pesticides (CWS and NTWS)
First 9 - year Compliance Cycle
I Begins Second 1
r 9 -year Cycle 1
CALENDAR
YEAR
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
;., ;..
,'/
',.
a>
|?
II
o
t
Repeat
Monitoring
1 Repeat
Monitoring
1 Repeat Monitoring 1
Round |
BASE REQUIREMENTS:
ALL SYSTEMS
'','.,' v'
;• , -',"!'' .- ,„ "*:
• 4 quarterly
samples at each
sampling point
4 quarterly
samples at each
sampling point
4 quarterly
samples at each
sampling point
4 quarterly
samples at each
sampling point
REDUCED MONITORING:
SYSTEMS WITH NO
PREVIOUS DETECTION
, -, ',"
, " •••".)—' •-_'
' , ''.', ' '•: , ,
•'/"?"••'/ "" •'• '" '" >
Not Applicable
t
Systems Serving:
> 3.300 • 2 samples at
each sampling point
< 3 .300 - 1 sample at
each sampling point
\
Systems Serving:
> 3.300 - 2 samples at
each sampling point
< 3 .300 - 1 sample at
each sampling point
t
Systems Serving:
> 3300 • 2 samples at
each sampling point
< 3300 • 1 sample at
each sampling point
WAIVERS *
• - •'•';';' .. . . •
t
Waiver
}
Wai>
1
t
Wai
J
I
/er
r
i
ver
\
t
Waiver
NOTE: States will designate the year during each compliance
period in wnteh each system must monitor.
*. Based on '\M»' and/or
(No Samples Required)
-------
Pesticides Monitoring Flow Chart
Initial Frequency
1993-1995
>
4
quarterly
samples
All CWS and NTWS
(beginnng 1993)
No
sampling
while waver
in effect
Waiver?
(effectve 1 period)
>3,300:2 samples
per period
300:1 sample
per period
Detect?
(at MDL tor each
contaminant)
Quarterly
sampling
No
sampling
while waiver
in effect
Reliably
conaste
-------
Fact Sheet on Unregulated
Contaminants
EPA Phase II Monitoring Series (8 of 8)
April 1991
This fact sheet summarizes the one-time monitoring requirements for 24 organic and 6 inor-
ganic chemicals as promulgated on January 30,1991 under the U.S. Environmental Proiecuon
Agency's (EPA) Phase II Rule. These requirements will taJte effect on July 30.1992.
Unregulated
Contaminants
Organtes
Aldrin
Ben2o(a)pyrene
Butachlor
Carbaryl
Oalapon
Di(2-ethylhexyl fedipate
Di(2-ethylhexyl)phthalateg
Dic&mba
Dieldnn
Dinoseb
Diquat
Endothall
Glyphoaate
Hexachlorobenzene
Hexaehlorocyclopenudiene
3-Hydroxycarbofuran
Methomyl
Metolachlor
Methbuzin
Oxunyl (vydate)
Pidormm
PropmcbJor
Sim wine
2A7.8-TCDD (Dioxin)
Inorganics
Antimony
Beryllium
Nickel
Sulfate
Thallium
Cyanide
Systems Affected
All community water systems (CWS) and nontransient noncommunity water systems
(NTWS) must conduct monitoring for the 24 organic and six inorganic chemicals' see
sidebar for lists of contaminants).
Sampling Points
Sampling must be conducted at each entry point to the distribution system. Sampling
points must be representative of the well or source water after treatment
Sampling Requirements
All systems must conduct a one-time round of sampling, unless a waiver has been
granted by the state (see below for summary of waiver requirements i The specific
sampling requirements are:
1) For the 24 organic chemicals, systems must take four consecutive quarterly
samples and report the results to the state.
2) For the six inorganic chemicals, systems must take one sample and report the
results to the state.
3) Sampling must be completed no later than December 31,1995.
Confirmation Samples:
Ibe state may require a confirmation sample for positive or negative results.
Compositing
Composite samples are allowed at state discretion from no more than five sampling
points. Compositing of samples must be completed in a certified drinking water
laboratory.
1) For systems serving greater than (>) 3300 persons, compositing is only allowed at
sampling points within a single system.
2) For systems serving less than (£) 3300 persons, compositing among different
systems is permitted.
Unrtguloted Contaminant!—/
-------
Waivers
Systems may apply to the state for a waiver from the sampling requirements. Such
waivers may be granted for either the organics or inorganics, or both, as follows:
1) Waiver for Organics: When a system can rule out previous use of the chemical in-
the water supply area (i.e., the contaminant was not used, manufactured, stored or '
disposed of in the area), the system can apply to the state for a "use" waiver. tf^fc
previous use is unknown, then systems may still qualify for a waiver by evaluA^
susceptibility. "Susceptibility" waivers are contingent on the conduct of a thorough
vulnerability assessment. The state may grant a "susceptibility" waiver based on
an evaluation of prior analytical and/or vulnerability assessment results (including
those of surrounding systems), environmental persistence and transport, how well
the source is protected, Wellhead Protection Assessments, and proximity to
sources of contamination.
2) Waiver for Inorganics: The state may grant a waiver if previous analytical
results indicate contamination would not occur, provided this data was collected
after January 1,1990.
3) Waiver for Very Small Systems: Systems serving fewer than 150 service
connections may obtain a waiver by sending a letter to the state indicating that the
system is available for sampling. This letter must be sent to the state by January
1,1994.
Unrtgulaud Conia.- unantt—2
-------
iuai
murwonng rrameworx:
Unregulated Contaminants (CWS and NTWS:
CALENDAR
YEAR
BASE REQUIREMENTS:
ALL SYSTEMS
Orgontcs
inorgorwcs
WAIVERS
1991
1992
h«%«k%%
1993
1994
t
4 Quarterly
samples at each
sampling point
l sample at each
sampling point
t
Waiver
NOTE: States will designate the year during each compliance
period in which each system must monitor.
BOMd on '(*•' and/or
(No SamptM R«qufr«d)
Unrcgulaud Coruaminanu—3
-------
Unregulated Contaminant Monitoring
Flow Chart — Inorganics
Repeat Frequency
1996-1998,1999-2001, etc.
Initial Frequency
1993-1995
AIICWSandNTWS
IS/System size <150
connections?
Send letter of
availability to
state
Previousdata
with no detects?
No
monitoring
requirBd
One sample
during initial
period
r for Increased
Frequency
^ - ,;: , ,
.v&iVS?''**.' - «rfXt^"*>.<' •• "» ' ' "<
Unregulated Contaminant—4
-------
Unregulated Contaminant Monitoring
Flow Chart — Pesticides
Initial Frequency
1993-1995
AIICWSandNTWS
!H£/System size <150
connections?
Send letter of
availability to
state
4
consecutive
qtrty samples
Awing initial
period
No
monitoring
required
IHgger for Increased
: Frequency
State
discretion
Repeat Frequency
1996-1998,1999-2001, etc.
UnrtgulaUd Coiterm
-------
Standardized
Monitoring
Framework
U.S. EPA Office of Drinking Water February 1991
-------
STANDARDIZED MONITORING FRAMEWORK
Background
Existing and forthcoming regulations under the Safe Drinking Water Act (SDU'A
contain significant monitoring requirements for public water systems. These requirements
vary by factors such as type of contaminant, system size and vulnerability status. Because 3
uniform schedule or framework for monitoring did not exist, EPA standardized mor.itor.r.c
in the recently promulgated Phase n regulation for 38 inorganic and organic contaminants
EPA's use of a standard monitoring framework will apply to future monitoring requirerr.er.tf
for inorganics, Volatile Organic Chemicals (VOCs), pesticides, and radionuciides. Requirerr.er.:?
for currently regulated contaminants will be integrated into the framework when the existir.c
regulations are revised.
Objective
The degree of variability among monitoring requirements poses both management ar.c
technical barriers for states and water systems that are ultimately responsible for implementing
the regulations. Consequently, EPA desires to standardize and simplify monitoring
requirements and synchronize monitoring schedules where possible. Benefits of such actier.
include:
>• Reducing the complexity of the monitoring workload from a technical and
managerial perspective for both states and water systems;
>• Leveling out the resource expenditure for monitoring and vulnerability
assessments;
>• Reducing sampling and vulnerability assessment costs.
>• Increasing water system compliance with monitoring requirements.
Applicability
The monitoring framework applies to source related contaminants associated
with chronic health effects. Contaminants associated with chronic health effects
include; VOCs, pesticides, radionuciides, and inorganic chemicals (with the
exception of nitrate/nitrite).
-------
"he Standard Framework
>• 3/6/9 Monitoring Cycle •
• A nine-year compliance cycle (beginning in 1993) is established for all r--r'.:^
water systems.
• Each nine-year compliance schedule is divided into three three-year corr.p::ar.ce
periods.
4
• All compliance cycles and compliance periods operate on a calendar year r^;:s
(January 1 to December 31).
• The first nine-year cycle begins January 1,1993 and ends December 31,2001. The'
second nine-year cycle begins January 1, 2002 and ends December 31, 2310 ar.d
soon.
• Within the first compliance cycle, the first compliance period begins January '.
1993 and ends December 31,1995; the second begins January 1, 1996 and er.-;
December 31,1998; the third begins January 1,1999 and ends December 31,2;;:.
• The Federal requirement to phase-in monitoring by system size and community/
non-transient water system classification is eliminated.
• Instead, EPA will require states to schedule approximately one-third of th
systems to monitor during each year of the three-year compliance period. Eacr
state has the flexibility to establish its own monitoring plan. For example, stares
may prioritize monitoring based on system size, vulnerability, lab capacity. ar.~
communiry/non-rransient non-community criteria.
• Once a state schedules a system to monitor during a particular year of the three-
year compliance period, (e.g. the system monitors in the second year or the
compliance period) that system must monitor in the same year in subsequent
compliance periods, (e.g., the second year).
>• When Initial Monitoring Begins
• When a regulation is promulgated during the nine-year compliance cycie. the
initial round of monitoring is required in the first full three-year compiiar.ee
cycle which begins 18 months after the date of promulgation (the effective date
of the regulation). For example, if Phase V is promulgated in March 1992. the
effective date is September 1993,(18 months after promulgation) in the middle
of the first three-year period. Consequently, the initial round of monitoring
would" not begin until the second "three-year compliance period (1996 - 1998).
This means initial monitoring for Phase V contaminants would be conducted
during the second three-year monitoring periods (1996 -1998) and the repeat
monitoring period would begin in 1999.
-------
Standard Framework, cont'd
Standard Monitoring Requirements
• All systems must sample at the base (or minimum) sampling freauer.cies.
• All systems have the same iniriai base sampling requirement regardless c:
system size or water source (except for inorganics).
• Most systems have the same repeat base sampling requirement regardless o:
system size or water source. However, differences for specific contaminants do
exist for pesticides based on system size (see Example 2).
• All systems which detect contamination must sample quarterly at each sarrriir.s
point detecting contamination until the state determines that the analytic?.;
results are "reliably and dependably" below the MCL. Detection is defined :•?:
the MCL for the inorganics; 0.0005 mg/1 for the VOCs, and at the ar.alvtic?.!
Method Detection Limit (MDL) for the pesticides and PCBs. In addition to tr.e
original sample, ground water systems must take a minimum of two additional
quarterly samples and surface water systems a minimum of four additional
quarterly samples before the state can determine that analytical results are
"reliably and dependably" below the MCL.
• "Reliably and dependably" below the MCL means that though the system
detects contaminants in its water supply, it has sufficient knowledge of the
source or extent of the contamination to predict that the MCL would not be
exceeded. Wide variations in the analytical results or analytical results near
the MCL would not meet the "reliably and dependably" test.
• Generally the repeat sampling requirements are reduced after initial
sampling. For example, the initial sampling requirement for the VOCs is 4
quarterly samples; the repeat sampling requirement is 1 sample annually.
• Waivers are available to all systems based upon a vulnerability assessment
and/or consideration of prior analytical results. Waivers either reduce the
sampling frequency (e.g. inorganics and VOCs) or eliminate any sampling
frequency (e.g. pesticides, asbestos, and unregulated contaminants). See
Examples 1-5.
Grandfathering of Data
• At a system's (or state's) discretion, sampling data collected three years prior to
the beginning of the initial three-year monitoring period can be used to satisfy
the initial sampling requirements. Systems using this grandfather provision
would then sample at the repeat frequencies which generally are lower than the
initial frequencies.
• Vulnerability assessments may not be grandfathered.
3
-------
Standard Framework, cont'd
>• Waivers
Base sampling requirements apply to all systems unless the requirement are
waived (either reduced or eliminated) by the state.
All waivers are granted by the state based upon a vulnerability assessment or
evaluation of prior analytical results.
Waivers obtained for asbestos, pesticides, and unregulated contaminants relieve
the system of any sampling requirements. Waivers for inorganics or VOC s
reduce the sampling frequency. Waivers are not available for nitrate a:
-j „;.,.
Waivers based on vulnerability assessments are effective for three-years for
pesticides, up to six years for VOCs, and up to nine years for the inorganics
After the waiver expires a new vulnerability assessment (generally an update of
the previous assessment) is required to obtain a waiver.
The extent of the vulnerability assessment depends on whether the system* s; :n
question had monitoring data available or the results of a previous assessment.
The lack of data would necessitate a more extensive vulnerability assessment.
Minimum criteria for vulnerability assessments are specified in each recui^irr..
A waiver must be granted for each specific contaminant. Waivers are rased'
upon an assessment of a system's vulnerability, which includes its previous
monitoring results.
-------
Waivers & Vulnerability
Assessments
Waivers
EPA has established provisions whereby States may waive (either eliminate or reduce •
base sampling requirements if certain conditions are met. Waivers based on vuinerab::::v
assessments are granted for three year periods. There are two basic types of waivers:
1) Waiver by Rule: For systems meeting established criteria. Example: inorganic?
where three samples less than the MCL are the criteria. All systems (regardless
of size) can qualify for waivers. Systems which do not receive waivers must
sample at the regulatory minimum.
2) Waiver by Vulnerability Assessment
>• A simplified two-step waiver procedure is available to all systems.
Step # 1: "Use Waiver" - Was the contaminant used, manufactured, stored or
disposed of in the area. If not, a waiver is granted. If yes or
unknown, system determines susceptibility.
Example: pesticides
Step # 2: "Susceptability Waiver" - If a "use" waiver can not be granted, a
thorough vulnerability assessment of the water source must be
done to determine "susceptibility" to contamination.
"Susceptibility" considers:
• Prior analytical and/or vulnerability assessment results;
• Environmental persistence and transport of the contaminant:
• How well the source is protected;
• Wellhead Protection Program reports; and
• Elevated nitrate levels.
Systems with no known "susceptibility" to contamination, based
upon an assessment of the above facts, may be granted a waiver
by the state. If "susceptibility" can not be determined, a system is
not eligible for a waiver. Systems which do not receive a waiver
must monitor at the regulatory minimum (i.e. base requirement).
Example: VOCs.
>• The State, the system, or*a third party organization can conduct the
assessment. However, the state*must approve the assessment.
>• Systems which do not receive waivers must sample at required base
frequencies.
-------
Nine-Year
Drinking Water Monitoring
Compliance Cycle
Year 9
Begins next
9-year Cycle
I
Year 1
First
Initial 3_Year
YeQr2 Monitoring Compliance
Period
Year 3
2
y
« Year4 ^ Second
§ Repeat 3-Year
5. Monitoring compliance
§ Year5 |. Period
o
0>
O Year 6
Year?
Third
Repeat 3-Year
Y g Monitoring Compliance
Period
-------
Standardized
Monitoring
Framework
COMMENTS
>• Phase II promuigcrec • Jc-
Phase ii effective - —.v 'vS2
>• Phase V promuiccrec •
3 Year Monitoring Period
Initial monitoring segirs 'o
Phase ii-1993
Compliance
3 Year Monitoring Period
>• Repeat monitor:,-a 'or P^cse
3 Year Monitoring Period
>• Repeat monitoring 'cr P!-cse
3 Year Monitoring Period
Compliance
3 Year Monitoring Period
3 Year Monitoring Period
-------
Standardized Monitoring Framework:
CWS and NTWS
Asbestos
o
'j
>
0
O
o
0
a
o
u
o
o
>-
1
a
~
''• Begins Second |
j 9 - year Cycle
J 1
CALENDAR
YEAR
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
1 Initial Monitoring
Round
Repeat
Monitoring
1 Repeat
Monitoring
1 Repeat Monitoring
Round
BASE REQUIREMENTS
*.
1 sample at
eacn sampling
point
1
No Requirements
1
t
No Requirements
1 sample at
each sampling
point
" V
WAIVERS
(ALL SYSTEMS)
Waivers Scsec c.~
Vuir.ercc. ••!
Assessment
(No Sc'-.c es ~sc- -=r:
Not Appnccc'e
1
1
Not Apphccc:e
1
Waivers scsec c"~
Vulnerapi'.i'v
Assessment
\
NOTE: States will designate the year curing each compliance
penoa in wnich each system must monitor.
3
-------
Standardized Monitoring Framework:
Pesticides
- . •"
o
CJ
(J
0)
u
o
a
0
a
>>
0
1.1
1®
8£
£u
00 _
J2?
.5= ^
O5 ,
£<>
-4—
CALENDAR
YEAR
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
0)
O**
_ -»
o H
25
f-
0)
Repeat
Sonitofin
2.
C!
Repeat
lonitofin
^
o
o
•JiTJ
i§
« O
*• Q£
1
BASE i?EQU!REMENTS:
ALL SYSTEMS
- -• ..--.- ...- v. - ..- . - v.-:vX-:-.-
- . -•-- •,•*.-,•,','.-.-.
• '• •• -.-. •::'• J'^iS'tS?-
t
4 guarrerty
scmoies at each
icnr.ciing point
i
t
4 quarrerty
samotes at each
sampling point
1
t
4 auarterty
samples at each
sampling point
1
t
4 quarterly
samples at each
sampling point
I..
REDUCED MONITORING:
SYSTEMS WfTH NO
PREVIOUS DETECTION
^feasp^^2^^&|;;j.-a:.i,,.,:..
-: ". .':•:'.''. :-:-:.x-:::':"?:""'-':--:-":Vi-. :: ''.'Siv/:^'';'-'-''. . -' •'••• *"• :'-' '';-
•:•: . . :•. .-.-.-; .-.-:%•.-;•:-:•: ;: :•:•:•.-.• -. - •;• -:•:•:-.•: :.;•:•:•:.,;:-.-: •. . . - . - • •
t
1
Not Applicable
Systems Serving:
> 3.300 - 2 samples at
each sampling point
< 3^00 - 1 sample at
each sampling point
t
Systems Serving:
> 3.300 • 2 samples at
each sampling point
< 3.300 - 1 sample at
each sampling point
t
Systems Serving:
> 3200 • 2 samples at
. each sampling point
< 3.300 • 1 sample at
each sampling point
./ 1
WAIVERS*
t
1
Waiver
Waiver
1
1
t
1
Waiver
1
I
f
1
Waiver
1
1
NOTE: States will designate the year during each compliance
period in which each system must monitor.
Based on'use'arc :•
'susceptibility1 asse»--v
(No Samples Rec- •?"
-------
Standardized Monitoring Framework:
Inorganics
CWS and NTWS
••••M
.2
5-
o
/-I
CJ
/~
o
1
0
U
5
IX
O
?*
8"
£u
in ^-
•sg
of
g*
CALENDAR
YEAR
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Initial Monitoring
Round
1 Repeat
Monitoring
[Repeat
Monitoring
1 Repeat Monitoring
Round
BASE REQUIREMENTS
SW
• •' • ,,.c-:;:^:::::;:>€:lllli
1 sample at
each sampling
point
1 sample at
each sampling
point
i sample at
each sampling
point
1 sample at
each sampling
point
1 sample at
each sampling
point
1 sample at
each sampling
point
1 sample at
each sampling
point
1 sample art
each sampling
point
1 sample at
each sampling
point
1 sample at
each sampling
point
1 sample
each sampl ating
point
1 sample at
each sampling
point *
•iMBMM^M
.:.^^:"S;::**<^iixSiKiSia^:S^3a:::::;.
'K-/'^-::^r-i^&?'-
^:m^imm^m^-
'::-:;E::;:«;ii|pli|:li|;I:;!:;;.;:
t
1 sample at
each sampling
point
I
t
1 sample at
each sampling
point
;
t
1 sample at
each sampling
point
1 sample at
each sampling
point
. 1
WAIVERS
(ALL SYSTEMS)
•••MHMMMMMMMHMM
State rr.cv waive the case
monitoring requirements
after 3 samcies of less tr.cn
the MCL are taken
'
1 sarr
each s
pc
i
^
pie at
ampiing
Hint
: — ,
•
NOTE: States will designate the year during each compliance
period in which each system must monitor.
10
-------
Standardized Monitoring Framework:
Volatile Organic Chemicals
- ." i« •
o
u
>>
U
o
u
c
0
a
0
U
0
o
>.
o
~
[_ Begins Second
[ 9 - year Cycle
CALENDAR
YEAR
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Initial Monitoring
Round
Repeat
Monitoring
1 Repeat
Monitoring
1 Repeat Monitoring
Round
BASE REQUIREMENTS:
ALL SYSTEMS
• : * v :>: * ™V "* ~XT%,XV 3Z* */^"!
4 quarterly
samples at each
sampling point
4 quarterly
samples at each
sampling point
1
4 quqrterty
samples at each
sampling point
4 quarterty
samples at each
sampling point
T *'»
REDUCED MONITORING:1
ALL SYSTEMS • GW SYSTEMS
"*. %*=*^^XTrrt8^r£/"s!<*.*
•*
*
\
*
*~
'*
1 sample at 1 sample at
each sampling each sampling
point. point.
IT M
'• II
- f
1 2
" 1 sample
I
- 1
- f
1
1 sample
•• 1
" t
1
•• 1 sample
I
..- 1
WAIVERS '
SVV < GVV
¥.-.- •• •:•;. •*
»
\
\
t
\
»
^
ti1
State J
discretion |
i\
A , scr
[i
State ,'
discretion «
iu
fi
State «
discretion J
\\
f r
State J
discretion «
liJ
i
* *^ t A
r
k
CIS
r
1: Provided initial monitoring completed by 12/31/92
and the system had no detection.
2: Reduction allowed after no detection In three yean
of annua monitoring.
11
NOTE:
States will designate the year
during each compliance penod
In which eocn system must manner.
-------
Standardized Monitoring Framework:
Unregulated Contaminants
CALENDAR
YEAR
BASE REQUIREMENTS:
ALL SYSTEMS
Inorganics
WAIVERS'
1991
1992
o
u
>>
U
o
U
q
a.
o
U
o
o
1993
1994
1995
o>
Is
o r
55
t
4 quarterly
samples at each
sampling point
l sample at each
sampling point
1
f
Waiver
I
1996
1997
1998
O5
o-i
OJ O
1999
2LXO
2LX1
O)
o o
»',,•* * * *
x>
" x -*4
.J%£
'6 ,
t
2002
2003
2004
O)
o
<>$r
£*^t '
"V«i.»>,f! •• "TIT.-
C.\ " ''X*
•«"-,' —,•?* *'" * y "'"?*
"*« \- £<< -">^fcS
* * ~, , , &*%
- -*» > }, >,X
NOTE: States will designate the year during each compliance
period in which each system must monitor.
Based on 'use' and/or
'susceptibility* assessment
(No Samples Reauirea)
12
-------
STANDARD
MONITORING
FRAMEWORK
(Another
View )
Initial Monitoring Requirements Page 1
Repeat Monitoring Requirements Page 2-3
Waiver Monitoring Requirements Page 4
-------
Contaminant
Asbestos:
Nitrate
INITIAL MONITORING REQUIREMENTS
System
Classification
_ ,i
All
GW
SW
TO
Sampling
Frequency
1 sample/3 Years
1 sample I Year, for 3 years
1 sample/quarter, beginning 1st quarter. 1993
i /Year, every year
28-Feb-9
Remarks
State* may grant waiver* from even Initial monitoring to cyctemi that can
demonstrate that they are not vulnerable. Waiver* must be renewed by the
beginning of each three year compliance period.
All PWS* mu*t monitor for nitrate.
SW *y*tem* may reduce the quarterly sampling to annual. If all result* of lour
consecutive •ample* are lev* than half the MCL.
Nitrite:
Art
1 sample/3 Years
Other tOCs;
QW
SW
1 sample/3 Years
1 sample / Year, for 3 years
All
4 consecutive quarterly samples / 3 Years
If all 18 VOC* (Phase 1» Pha*e II) are monitored after 1/1/88 and not detected.
the State may authorize the system to begin annual sampling in 1003.
PCBs & SOCs:
Unregulated;
All fp 4 consecutive quarterly samples / 3 Years
lOCs 1sampte/3Years
SOCs 4 consecutive quarterly samples/ 3 Years
II Initial campling detect* any pesticide*, the system must begin sampling
each quarter. II • State determine* a system I* reliably and consistently below
the MCL (minimum ol 2 qtr* for QW and 4 qtrs lor SW), It may reduce the tamp
frequency to annual.
! the
otherwise, these requirements apply to all CWSs and NTNCWSs.
of any cample exceed (he MCL, the system must begin quarterly monitoring in the
quarter.
-------
REPEAT MONITORING REQUIREMENTS
1 REPEAT I
, yr> ,; ~ •
ff '~
Contaminant
Asbestos :
All: 1/3 Yr*
... .:....• NitratA •
QW: 1/YrX3
6W: 1/Otr
TO: 1/Yr
NttritA •
AS: 1/3 Yr*
Other IOCS :
6W: 1/YrX3
! ':?r '"' >v""!^1-*1""" '''
System Frequency: Sampling
Classification Trigger;-; ; > Frequency
GW > MCL 1/QTRX2
< MCL 1/9 Yrs.
' :: % • • SWiit ,i: A ; > MCL ' 1 / QTR X 4 ; . .
< MCL 1/9Yrs-
"•'• |"?IA/A 1/7 Mfil :* ::"':-:'. . 1/OTRX4
'"X {•'••• '•• '--;:::C ": :< 1/2" Met! ;^f.H/YH":: •'*•"'..';
TRANSIENT — 1/YR
AH •%. 1/9 uni i i rxm Y A
< 1/2 MCL State Discretion
GW > MCL 1/QTOX2
:•:•::. ;••.•. ' « « a V»*» V 9
SW > MCL !;>,;: 1/OtRX 4
< MCL 1 1/YRX2
28-Feb-91
* *
Remarks
:: The • 1 / a Yr*.* reqiriremaot 1* that the umpla mud be Uken during the fir«t 3
compliance period of each rrino y»ar oompllanoa cycle.
._ , , ff ^_ . , , f^^ , — t
to annual. H the mult* ara reHabty and eohcMontly b*4ow the MCL
II ..11,. rt^.1 ,0» n .4 It, L
to annual. If the rtmjlte mrm reliably and conrirtentfy below the MCL
AD tyetem* mutl lake a minimum of 3 round* of samplea. Indodln^ the Initial
^^_ - ' .'.. ^*^ L
* Unlesi noted otherwise. lhe«e requirement* apply lo all CWS* and NTNCWS*.
* * II the result* of any cample exceed the MCL. the tyetem mud begin quarterly monitoring In the following quarter.
-------
REPEAT MONITORING REQUIREMENTS
: |REPEAT 1
28-Feb-9l
Contaminant System Frequency
Classification Trigger
:: VOCS : GW >MCL
AH: 4/SYra-; : -- - ; WS. '• < MCL
•'•'.' . f ':'•','•' '•'•: •' ',•''• '•"'.-' ' .•. .'•'••'';''•:'•;•.'.•; :•.•;•:"''• '•' -•• IMo fittfiTW*!*
• "" *" ';•'•. .'", .':•:''":' •: • . . . " :":":•:•:•'•;":';":': .
:,. '^^ :/: •',. • " ' ;--|ifi:> V. SW > MCL
:': • ': • ' 'i;;.:' < MCL
PQBs&SQCs: All > MCL
Ml: 4/SYre
;- ' '; ';;|':f :%-.•;: •:= . ": ' GW> 3.300 Detect
No Detect
v: -. :-:-:r.:-.;\ GW < S.SOO .. Detect -: '
•';•••- ••*;:i^';- ' ''' -•'• No Detect
i SW > 3,300 Detect
il.£M:f;'.Vr No Detect
•.;. ,-:::--:'::Ti; ;.;:!' • :- SW < 3,300 .; Detect
No Detect
Sampling
Frequency
1/QTFIX2
1/YR ^m... ;;f:. .::.;,
1/YRX3. 1/3 Yrs
1/QTRX4
1/YR
1/QTRX4
1/QTRX2
2/3Yrs
1/CFTRX2
1/3 Yrs
1/QTRX4
2/3Yrs
1/QTRX4
1/3Yrs
Remarks
OW systems must take a minimum of h»o consecutive quarterly aamplee below
: In*) MCL, arid SW syetems must take a minimum of tour consecutive quarterly
sample*, before » SUte may reduce the) monkoring to annual.
Glatse may allow QW systems with no detect* lor 3 consecutive years to reduce
: the sampling frequency to once each 3 year eompBance period.
:" '-. ••:.:• . .:. •. - ••••.':• '•'•. v ". - •: '. •" - ' :. .;
QW system* imiet take a minimum of two oonaecuttvei quarterly eamplee below
the/ MCL. and SW systems must take a minimum of four consecutive quarterly
samples, before a State may reduce the monftortng to annual. .
1
....
rtherwise. these requirements apply lo all CWS» and NTNCWS*.
* * II the result* ol any sample exceed the MCL. the system must begin quarterly monitoring In the loHowTng quarter.
-------
iih ' Ji? & '„• ', *" > ;IY T
MONITORING
WAIVER REQUIREMENTS
m^"' "-,-54's
t S >s ' ••
vt«5; «t»* -v
28-Feb-9!
Contaminant
Asbestos
System
Classification
All
Sampling
Frequency
None
Waiver
Duration
Remarks
3 Years : States may grant waivers from even Initial monitoring requirements.
Nitrate:
Monitoring waivers are not authorized for nitrate.
Nitrite:
Monitoring waivers are not authorized for nitrite.
Other IQCs:
All
1 sample/9 Years
3 Years All systems must have a minimum of 3 consecutive rounds of
sampling with results below the MCL.
VOCs ;'=
PCBs & SOCs:
GW
SW
All
1 sample/6 Years
i i State Discretion
Nona
6 Years •:.: AN systems must have a minimum of 3 consecutive rounds of
6 Years sampling with results showing no detects.
Results of vulnerability assessment must be reconfirmed by the State
within the first three years of the waiver period, or It becomes void.
3 Years All systems must have a minimum of 3 consecutive rounds of
sampling with results showing no detects.
Unregulated; AH
< 150 Connections
None
None
Indefinitely Same criteria as for regulated contaminants of the same class.
Indefinitely Systems serving less than 150 service connections who notify
the State In writing that they do not Intend to sample unregulated
contaminants will legally avoid doing so, unless the State tells
them otherwise.
Unlem noted otherwise, these requirements apply to all CWSs and NTNCWSs.
If the results ol any sample exceed the MCL. the system must begin quarterly monitoring In the following quarter.
-------
37 ()9'9l 14:34 *J202 382 3464 EPA
r ISTISSUE I June 25, 1991
The unit costs in the attached analysis are apprcsdrnaie fcr the reasons steed below. There's also a
semantical issue in that the data is based on one sampling sfte. Soma people may tend to extrapolate these costs to
larger systems and calculate a linear per capfia cost reduction ss the number of service connectors increase. That
assumes ait systems have only one sampSng site regardless cf population size. But, as systems get larger, the number
of sampling sites tends to increase as well. Each additional sampling site represents a multiple of the per connection
-rnenthh? T*? The upshot Is that although per connection sampling una*. wit! land to decrease as system size
inoremai,, trie change w not linear bccauttf of th» ineiwaring number Of campling stfcs.
ANALYTICAL METHODS
me cost cr omerent anayucaf metnods suitable Tor me same corssminant will vary, aid pricing of tne sane
ansfyiicai method wffl vary among commercial labs.
For this anatysis, the lowest cost methods are used, and usually the lowest cost for which a method can be
performed is used; except where a cost range has been determined, in which case the median of tne rsnge is used.
GRANDFATHERS? DATA (GFTi
The cost of grandfatherod (Whenever the smaples wwa anafyzad, there was a cost invoived.) couid bs treated
«ther as a sunk coet ana excluded from cata.<
-------
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*I.2' •;*'. .•• •: i •£ ti,:': -JLj!>1ti™ ij:} 4 j •Ji.-I-.-J^ i» jx• r '^ f***-' T ^""* L'r* " 'g"| t~T*» li* "yy
i;Ji^;;;^;;v|a;^||iSwi1io,j;tlqni5[?i y^^jpJtKl::! |iHi?|?^jfO
-------
iiT-09/81 14:36 t?202 382 3464 EPA &004
£ COST5URF ] Jl^ 25. 199!
muiU. one sample every nine years (but during flna three year period, or 1 x untt COST.
High Repeat Cost/Year: quarterly samples, or 4 x unit cost.
Nine Year High Cost if initial sample is taken at the end of the third year • one initial sample plus quarterly samples for 6
years, or 25 x unit cost;
If (nhiai sample is taken at trie beginning of the first year - one initial ssmpfe, plus quarterfy
samples for trie rest or tnat year, plus quarterly samples tor eignt more years, or 36 x unit cost
Lou Repeat Cos/Year one sample every nine years, or unit cost * a.
Nine Year Low Cose one sample every nine years, or 1 x unit cost
Afarift Waiver CostArean no samples
Iniifsl Round: quarterly samples beginning in tha first quarter of 13S3. or 4 x unit cost.
High Repeat Coot/Year quarterly samples, or 4 x unit cost
Nine Year Hign cose quarterly samples for nine years, or 36 x unit cost
lotf Repeat. Cost/Yean one sample every year, on x unit cost.
Nine Year Low Cost 7 prior data is grandfathered for the initial round - one sample each year for nine years, or s x unit
cost
if prior daia (s net grandrainerea" - Ttie cost or Tour quarterly samples tor we initial round in trie first
year, plus the cost of one sample each year for the reamafriing eight years, or 12 x unit cost
Mont Waiver Cost/Yean waivers are not authorized
Nrmrre
IrriSal Round one sample in three years, or 1 x unit cost
High Repeat Cost/Year: one sample each quarter, or 4 x unit cost
Mine Year High Cswe if the initial sample »taken in the last quarter of 1SS5 - tne coat of that sample, plus the cost of
quarterly samples forme remaining sot years, or 25 x una cost
ff the inftfai sample is taken in Cie first quarter of 1993 - the cost of quarterly samples for nine
years, or3Sx unit cost
Law Repeat CcefYeen no eampTuig required.
Nine Year LCMT Ccsc IT previous cara Is grancrajtiered for the tntttal sample, no sampling further sampling is required
tf no previous data is c^andfathered for the first round - the cost of the inflial sample, or 1 x unft
cost.
MonSWasver Cost/Year waivers are no? authorizedL
-------
O7.'08/Sl
[ COSTSURF ]
14::
G202 382 3464
EPA
©UC5
June J5, 1991
OTHER INORGANIC CHEMICALS
one sample in every year, or 3 x ur3 ccst
High Repeat Coed/Yean one sample eaoh quarter, or 4 x unit cost
Nine Year HI^I Cose one sample each quarter - H tne initial sample is taxen (n me first ^carter cr lass, the cost of that
sample, the cost of three quarterly samples for the remainder of that year and the cost of quarterty
samples tor the following eight years, or 36 x un?t cost
if the Initial sample is taken fn the last quarter of 1933 - the cost of that sample plus quarterly
samples for the remaining eight years, or 33 x unit coat
one sample every year, or 1 x unit cost
one sample every year, or 9 x unit cost
Low Repeat Cost/Yean
Nine Year Lav Cost
Ltonft Waiver Cost/Yean one sample in nine yeais, cr unit cost * 9.
VOLATILE ORGANIC COMPOUNDS
JnEal Round:
High Rapaat Cos*/Yi
Ntoe Year High Cost
Low Repeat Coat/Year
Nine Year LOW cost
four consecutive quarterly samples, or 4 x unit cost
four camples each quarter, or « x unit cost
If the initial round Ts begun in isas • four quarterly samples for tfrat year, plus quarterly samples
for the remaining six years, or 23 x unit cost
If the initial • xmd is begun in the first quarter of 1993 - four quarterly samples for that year, plus
quarterty samples for each of the remainin.o eiont years, or 36 x unit cost.
one semple eeoh year, or 1 x unit cost
ir one sample & grandrathered for the infflai round - tne cost of tnai sample, plus tne cost of
annual samples for each of the nine yea's, or 10 x unit cost
ff no data is grandfatfiered - the cost of foLT quarterly samples in the first compliance period, plus
the cost of annual ea-nplae for the following six. years, or 1O x the unit cost
Morn waiver Cost/Year: no sampling is requires
ORGASflC COMPOUNDS. INCLUDING DlOXJN & PCBS
IriUai Ftoundt
High Repeat Cost/Year
Nine Year high cose
Low Repeat Cost/Yean
Nine Year Law Cose
Marat Water Cost/Yi
four consecutive quarterly samples, or 4 x unit exist
four samples each quarter, cr 4 x unit cost
if the urufai round is begun rn 1S9S • four quarterly samples for that year, plus quarterly samples
for tha remaining six years, or 28 x unit exist.
if the initial round is begun in the first quaner of 1SS3 - four quarterly samples for thet year, plus
quarterly samples ror eacn of me remaining eight years, or se x unit cost
for systems serving less than 3,300 people - one sample each compliance period, or unit cost + 3
(for systems serving more than 3.300 people, two samples every ttuee years).
f one sampte ie grandfethered for the fnftla! round - the cost of that sample, plus the cost of one
sample each compliance period, or 4 x unit cost
ff no data s grandfathered - four quarterly samples pius the cost of one sample for each of the two
remaining compliance periods, cr 6 x unit cost
no sampling is required
-------
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-------
f/08/ai
14:38
2 3S2 3464
EPA
31007
Juno 2$, 1991
;;L^3£SS15Ml3^^
ASBESTOS
irJfial Round: one sample every nine years (but during first three year period, or 1 x unit i
High Repeat CastfYean quarterly sample*, or 4 x unit cost
Mane Year High GCSC a initial sample is taxen at the end of the third year - one 'initial sample plus quarterly samples for 6
years, or 25 x unit cost;
if initial sample is taken at the beginning of trie first year - cne initial sample, plus Quarterly
camples for the rest of thai yaai, plus quarterly samples for eight more years, or 36 x unit cost
one sample every nine years, or unit onftt * s,
ons sample every nine years, or 1 x unit cost
Repeat CostfYear.
Nine Year Low Cost
Mortf Waver Ccsi/Year no samples
InSal Round: annual samples beginning in 1333, or 3 x unit cost
High Repeat Cost/Yean quarterly samples, or 4 x unit cost
Nino Year High Cost: If Initial sample is taken in the first quarter or 1993- quarterly esmptea for nine years, orSSx unit
cost
if initiai sample is taken in tfie test quarter of 1 933 - cne sample for that year, plus quarterly
samples for eight remaining years, or 33 x unit cost
one sarnpJe every year, or 1 x unit cost
one sample each year for nine years, or 9 x unit eost
Low Repeat Cod/Yean
Nats Ysar Law Coat
Mona waiver cost/rear waivers are not autnoreea
inSJai Round: one sample In tnree years, or i x untt cost
High Repeat Cost/Yean one sample each quarter, or 4 x unit cost
Nine Year High Cost if trie initial sample is taken in the last quarter of 1955 - the cost of tMat sample, plus the cost of
quarterly samples for tha remaining six yes^fi,. or 25 x ursl cost.
if the initial sample is taken In the Hrst quarter of 1033 - the cost of quarterly samples for nine
years, or 36 x unit cost.
no sampling required.
rf previous das. is grandfathered for the initial sample, no sampling further sampling is required.
if no previous data is grandfathered for the first round - the coat of 1he inWal sample, or 1 x unit
cost
Mona Waiver Costnrear. waivers are not authorized
Low Repeat Cost/Yean
Nina Year Low Cost:
-------
U " • fi Q 9 i
14:39
2 342 3i64
EPA
Jine 25, 1991
OTHER INORGANIC CHEMICALS
infial Round:
H(0i Repeat cosvrear
Nfce Year High Cost
Low Repeat Cost/Year
Nine Year Low Cost:
one sample In three yeare, or 1 x unit ccet
one sample eacn quaner, or 4 x unc cost
one sample each quaner - if the initial sample is taken in the Rrst quarter of 1993, the cost of that
sample, the cost of liree quoted/ samples for the remainder of that year and the cost of quarterly
samples for the following eight yeare, or 36 x unit eoet
ff the InWaJ sampte te taken In the last quarter of 1 sss • the cost of tree sample plus quarterly
samples for the remaining six years, or 25 x unit cost
ane sample every three years, or unit cost - 3.
one sample every three years, or 3 x cn'rt cost
Moral Waiver Cost/Year: one sample in rone years, or unit cost » 9.
. GRGANC, COMPOUNDS
Low Repeat Cost/Year.
Nine Tear Low Cose
Inftiel Round: four consecutive quarterly eamptes, or 4 x unit cost
Hign Repeal cosvresn TOW samples eacn quaner, or 4 x unit cost
Nine Year High Cose if the InMal round is begun in 1SS5 - four quarterly samples for that year, plus quarterly samples
for the remaining sec years, or 28 x unit cost
if the initial aund is begun in the first quarter of 1993 - four quarterly samples for that year, plus
quarterly samples for eech of the remaining eight yeera, or 86 x unit coat.
one sample every three years, or unit cost - 3.
If one sample is grandiathered for the initial round - the cost of that sample, plus the cost of two
more annual samples, plus the cost of one sample for each of the two remaining three year
compliance periods, or 5 x unit cost
if no data is grancrasnerea - trie cast of rour quarterly samples in the first compliance penoa, pins
the cost of two annual samples for the following two years, plus the cost of one sample for each
of the two remaining compliance periods, or 8 x the unit cost Of the four quarterly samples are
taken in 1665 • the cost of two annual camples in the second compliance period, plus the coct of
one sample en the third scmplianc* period, or 7 x urJt cost, which falfs wrtnin tlie range
established by the scenarios above.)
Monft Waiver Cost/Yean no sampling is required
OTOANIO COMPOUNDS. INCLUDINO DJOXIN & PCBa
inffiai Round: four consecutive quarterly samples, or 4 x unit cost
High Repeat Cost/Year four samples each quarter, or 4 x unit cost
Wine Year High Cost if the initial round is begun in 1996 - fcur quarterly samples for that ysar, p!ue quertsrly samples
for me retraining sx yeare, or 28 x unit cost
if the initial round is begun in tie first quarter of 13S3 - four quarterly samples for that year, plus
quarterly samples for each of the remaining eight years, or 36 x unit cost
Lav Repeat Cad/Yean tar systems saving less than 3,300 people - one sampte each comptianca period, or unit cost * 3
( for systems serving more tr>an 3,300 people, two eampies every three years ).
Nme resr LOW COST IT one sample ts granofatnered for me inwai round - the cost or thai sample, plus tne cost or one
sample each compliance period, or 4 x unrt cost
if no daia is orandfathered - Tour quarterly samples plus the cost of one sample for each of the two
remaining compliance periods, or 6 x unit coct
MORR waiver Cost/Yean no sampling te required.
-------
.
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>; s^feijiyUivftvasij^i^:! >!,:-:;:
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Nino Year High Cost
Nine Year Low Cost Nino Year Low Cost
w/o CompoaUes v»/ ConnpoalteB
Nino Yea Cost
wS Waivers
-*
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-------
Population
m%
Nine Year High Cost
Nine Voar Low Cost
w/o Composites
Nho Year Low Coat
w/ Composites
Nine YoaCost
w/ Waivers
tn
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PRIMACY APPLICATI
1. State Peculations / Authorities
- Enforceable provisions must be In the form of duly adopted regulations.
- Implementation procedures may be In the form of state policy.
- Enforceability of enforceable provisions under state law must be unambiguous.
. ' • ' '• : i
2. Crosswalks
ON
1 ••')•'
- Must address mandatory federal requirements and criteria of each optional element adopted e.g.. compositing samples.
- Citations of state provisions should Include document titles and page numbers for expeditious review.
3. Prbaram Description
- Must address state recordkeeplng. reporting, and monitoring plan implementation and enforcement.
- If State adopts or amends any of the following components In whole or part. PD must also address
Variances, Exemptions and Monitoring Waiver Approvals.
4. Attorney General's Statement
- Must unequivocally certify that the state program Is enforceable under state law.
- Must be signed before primacy approval.
>
>.-.- ,
" -
* "4
-------
PRIMACY CRITERIA
1. Mandatory Requirements
- Must be included In state primacy revision applications.
- Must meet federal criteria.
2. Optional Provisions
- May be excluded .from state primacy revision applications. »
- If a State chooses to use any of them) the state provisions must meet federal criteria.
3. Program Description
- Federal criteria to generally goal oriented.
- Parameters for state methods of achieving program goals to generally quite flexible.
'
* < 5 ' t'
-------
|l9|f^^v;4u:}>^ .- ; <
MANDATORY AUTHORITIES
1. MCLs/TTs. MDLs & Analytical Techniques
TT Is annual certification of proper A&E dosage; States should legally require systems to follow proper dosage criteria.
States may establish more stringent MCLs. or lower MDLs as technology warrants.
2. Monitoring Protocols & Sampling Frequencies
Includes nitrate and nitrite confirmation sampling, see Sec. 141.23(0(2))
,: i '• i '
States may set higher sampling frequencies or longer periods for establishing a 'reliable and consistent' baseline.
3. Compliance Calculations
States'may establish a shorter period than one year for rolling average, or eliminate the rolling average.
EPA assumes calculation occurs same day as lab results arrive.
, 4. Public Notice
5. State Monitoring Plan. Recordkeepinq & Reporting
States may establish longer record retention periods.
State M/R violations, which are not also federal violations, will Increase substantially; raising federal reporting Issues.
-------
J
OPTIONAL AUTHORITIES
2. Composite Samples
- State limit must be five samples or less. . .
- Multiple system compositing must bejlmtted to five system or less, each serving populations of 3.300 or less.
- State must require violation follow-up sample In 14 days or less.
2. Confirmation Sampling
- Confirmation sampling for nitrate and nitrite to mandatory, see Sec. 141 .23(0(2).
- States may designate highest reported value, but not lowest reported value, as baste of compliance determination.
3. Monitoring Waivers
- States may not reduce sampling frequency below federal minimum.
- State must account for contaminant migration rates during entire waiver periooXs).
4. Variances (including BATs) & Exemptions.
- State criteria for and conditions of Issuance must meet federal criteria and be enforceable under state law.
- Unavailable for A&E treatment technique.
- New 'regulatory variance* Is now In gestation - see handout.
•( ,
-------
VARIANCES & EXEMPTIONS
• - *
1. Consolidation & Rectification
POE & POU provisions that were formerly separate under variances and exemptions have been consolidated.
The subsection "(a)' Identifying BATs from which variances may be granted has been expanded to *(a)* for organic
chemicals and *(b)* for Inorganic chemicals, and succeeding subsections have been shifted down.
2. MCLs & BATs
The MCLs from which States may grant exemptions now Include all Phase I and Phase II contaminants.
The BATs from which States may grant variances now Include all Phase I and Phase II contaminants.
3. Other Changes
States may accept bottled water safety certifications from the botteW water regulatory agency of the State
In which the water Is bottled.
States requiring POU devices as a condition of a variance or exemption may cease to require a device in each bunding,
but must be assured there are a 'sufficient' number of devices properly Installed In the affected area.
-------
r -
PROGRAM
DESCRIPTION
1. State Recordkeepino 6V Reporting (mandatory)
PD must state unequivocally that records will be maintained for minimum periods or longer.
PO must state unequivocally that results of monitoring for unregulated contaminants will be reported each quarter.
2. State Monitoring Plan (mandatory)
Purpose Is to minimize M/R violations at the end of the Initial compliance period and to provide a management tool for
leveling out over time the system demands on state lab capacity.
For M. there is a codification / enforceablllty issue we can address with an effective sampling date notification letter.
3. Monitoring Waiver Process & Criteria (optional)
PD must provide a dear and detailed explanation of how the State will manage this program.
The procedures and criteria for state analysis must be equal to the complexity of geological circumstances
hi which waiver applications wilt be considered.
PD must account for contaminant migration rates during waiver period and provide a reasonable margin of safety.
-------
RECORDKEEPING
& REPORTING
1. New: 12 Year Rbtehtion Period
Designed to retain a rolling 9 year compliance cycle of records at all times.
Provided additional consistency with Standard Monitoring Framework.
2. New: Most Current Decision
Allows comparison of actual system performance wtth current requirements.
Provides audKable record of recent state decisions.
t
3. Unregulated Contaminants Reported Quarterly
Standard federal reporting frequency.
Data entry formats to be established by Technical Support Division.
'>'
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-------
STATE MONITORING PLAN
*
1. ' Improve Program Management
Provides a means to establish state priorities for which systems monitor first and which systems monitor later.
Provides a means for States to rationalize the ebb and flow of demand for lab services.
2. Organized Implementation
Plan should be wen thought out and account for the universe of systems under regulation.
Plan should describe SOPs for system notification of scheduled sampling dates and for compliance tracking.
3. Enforceable Under State Law
Plan should provide for aggressive enforcement against unwarranted failure to meet state schedule.
Plan should provide for timely reporting of federal M/R violations e.g., SW nitrate violations In the first quater of 1993.
-------
MONITORING
WAIVERS
1. Program Structure
•Use*/'Susceptibility-waivers :
Contaminants or contaminant categories for which waivers are available.
Types of systems for .which waivers are available e.g., GW serving fewer than 3.300 people.
2. -Fact Finding & Review
Application requirements and review procedures for -use* or 'susceptibility' waivers.
Means of accounting for contaminant migration rates over waiver period.
Analysis of contamination stte Inventory and of potential contamination sites.
3. Approval Criteria & Margin of Safety
Explicit decision criteria e.g., official finding that source contamination during waiver period to very unlikely.
Means of providing a reasonable margin of safety to account for geological ambiguities e.g.. arbitrary multiplier
In calculating contaminant migration rates.
* * •-,
-------
EPA
REVIEW
STATE
WAIVER
OF
DECISIONS
1. Criteria for Annulment
Failure to apply the standards of the approved state program.
ROs should act only when State is clearly wrong.
ROs should not second guess state Judgement.
2. Annulment Procedure
Issuance of draft decision wtth opportunity for state comment and public review.
Regional Office and State should make every effort to resolve this Informally.
Issuance of final decision must be signed by the Regional Administrator.
3. Effect of Annulment
Standard sampling frequencies for systems without waivers.
If State rescinds its monitoring waiver. RA may cancel Rectesion Order.
-------
:Standard.< Monitoring;: Framework-
ASBESTOS
Sampling Frequencies
YEAR
< HCL
> MCL
WAIVER
1993
1994
1995
1996
1997
1998
1999
2000
2001
Initial Sampling : All systems must take one sample every nine years during the initial compliance period
of each compliance cycle.
Exeeding the Trigger Level ; Any system exceeding MCL, must take one sample each quarter. If the sampling
results fall reliably and consistently below the HCL, the State may reduce the system's sampling frequency for
that sampling site to one sample every nine years; taken during the first three years.
Monitoring Waivers ; Systems granted a monitoring waiver are not required to monitor. The waiver must be
updated every nine years.
Contaminants : Asbestos
-------
MotnOOMQ JFfMMEWQRK
NITRATE
SAMPUNG FREQUENCIES
YEAR
SW
< Vi M C L
CORE FREQUENCY
GW
MCL
ALL
1903
1994
1996
1996
1997
1998
2000
2001
Intttel Samoino : SW systems must take one sample each quarter, beginning in 1993. GW systems must take one sample every year,
beginning In the 1993.
Sampling w/o a Waiver: SW systems may reduce their sampling frequency to one sample every year, if the initial four
quarterly samples are all less than V4 MCL
Exceeding the Trigger Level: Any system exceeding the Vx MCL must take one sample every quarter. If the sampling results fall
reliably and consistently below the MCL, the State may reduce a GW system's sampling frequency for that sampling site to one sample
every year.
Monitoring Waivers: Waivers are not authorized for Nitrate.
rtls: Nitrate
[ PHMEI, MIRKIEJXir
-------
Standard Monitoring Framework
NITRITE
Sampling Frequencies
YEAR
< ft NCL
> ft MCL
1993
1994
1995
^^mmtSS
1996
1997
1998
1999
2000
2001
Initial Sampling : Alt systems must take one sample during the initial compliance period (1993 - 1995).
Exeeding the Trigger Level : Any system exceeding Yi MCL, must take one sample each quarter. If the
sampling results fall reliably and consistently below the MCL, the State may reduce the system's sampling
frequency for that sampling site to one sample every year.
Reduced Sampling u/o Waiver : If the initial sampling results are less than 'A MCL, the system shall monitor
at a frequency determined by the State.
Monitoring Waivers : Waivers are not authorized for Nitrite.
Contaminants : Nitrite
-------
MOMTOHNQ
INORGANIC CHEMICALS
SAMPUNQ FREQUENCIES
YEAR
1993
1904
1996
1996
1997
1998
1990
2000
2001
CORE FREQUENCY
< MCL > MCL
SW GW : ALL
• I ! ••••
• • ••••
• i i ••••
•
• I ••••
• • ••••
• j i ••••
i !
• ••••
APPROVED WAIVER
ALL
•
Initial SamoBno : SW systems must take one sample each year beginning In 1993. GW systems must take one sample every three
years beginning in the first compliance period.
the Trigger Level: Any system exceeding the MCL must take one sample every quarter. If the sampling results fall reliably
and consistently below the MCL, the State may reduce the system's sampling frequency for that sampling site to annual (SW) or triennial
(GW).
Monitoring Waivers : Systems granted a monitoring waiver must monitor once every nine years.
Antimony
Barium
Beryllium
Cadmium
Chromium
Cyanide
Nickel
Selenium
Thallium
-------
5XMNHR0
FfMMEWCflX
VOLATILE ORGANIC COMPOUNDS
SAMPLING FREQUENCIES ~
YEAR
1993
1994
1995
1996
1997
1998
1999
2000
2001
< Detection Limit of .0005 mg/1 > .0005 mo/1
SW GW ! ALL
• •••
• ••• •••• ••••
• •••
• • ••••
• • ••••
• ••••
• ••••
i
• • ••••
• ••••
SW QW
•••• ••••
•
Initial Sampling ; SW & GW systems must take four consecutive quarterly samples each compliance period, beginning in 1993 [§141.24(f)(4)].
Qrandfuilmed
Sampling conducted between 1/1/88 and 12/31/92 (Inclusive) may be substituted (grandfathered) for the initial four quarterly
samples, so long as the sampling was conducted in accordance with §§141.24(f)(5) and 141.24(f)(18). This means that one sample collected during that
time period may be substituted tor the tour sample* required between 1/1/93 and 12/31/94 (inclusive) [§141.24(f)(5)J.
SampBng w/o Waiver; SW & GW systems which have no detects in their initial round of sampling, may reduce their sampling frequency to
one sample each year [§141.24(f)(5)]. QW systems, which have three years of sampling and no detections, may be allowed to reduce their sampling
frequency to one sample each compliance period (triennial) [§141.24(1) (6)].
Exceeding the Trigger Level; Any system exceeding the detection limit of .0005 mg/l must take one sample every quarter. If the sampling results fall
reliably and consistently below the MCL, the State may reduce the system's sampling frequency for that sampling site to one sample every year
(1141.24(901)].
Monitoring Wafrere ; GW systems granted a monitoring waiver must monitor once every six years (two compliance periods). The vulnerability
assessment must be updated every six years. During the first waiver period, the vulnerability assissment must be updated within the first three years of
that six year period. [§141.24(f)(9)]. SW systems granted a monitoring waiver must sample at a frequency specified by the State. The vulnerability
assessment must be updated every compliance period (three years) [§141.24(f)(10)J.
Contaminants;
1,1,1 -Trichloroethane
1,2-Dichloroethane
Carbon tetrachloride
p-Dichlorobenzene
cis-1,2-Dichloroethylene
Ethylbenzene
o-Dichlorobenzene
Tetrachloroethylene
trans-1,2-Dichloroethylene
1,1-Dichlorethylene
Benzene
Trlchloroethylene
Vinyl Chloride
1,2-Dichloropropane
Monochlorobenzene
Styrene
Toluene
Xylenes (total)
[PHASE I, VOLATLE.DOT]
July 8,1801
-------
STANDARD
SYNTHETIC ORGANIC COMPOUNDS
SAMPLING FREQUENCIES ~~
YEAR
1993
1994
1995
1998
1997
1990
1999
2000
2001
CORE FREQUENCY
< Detection Limit > Detection Limit
< 3.300 > 3.300 : ALL
j ••••
• ••• •••• ••••
i ••••
I
i
• • ••••
| ••••
: :
• • ••••
• •••
APPROVED WAIVER
ALL .
'••
MBal Samping : SW & OW systems must take four consecutive quarterly samples each compliance period, beginning In 1993 [§141.24(h)(4)J.
QmndfaBMred Bete : Sampling conducted between 1/1/90 and 12/31/92 (inclusive) may be substituted (gnmdfathered) for the Initial four quarterly samples. This
means that one sample coftected during tut thne period may be suhsaftri for tie tour samples required between 1/1/93 and 12/31/94 (inclusive) [§141.24(h)(14)J.
Water: Systems serving 3.300 people, which have no detects in their initial round of sampling, may reduce their sampling frequency to
i samples every three years (compliance period) [§141.24(h)(4)(ll)l- Systems serving 3,300 people or less, which have no detects in their Initial round of
sampling, may reduce their sampling frequency to one sample each compliance period (triennial) [§l41.24(h)(4)(UQ].
the Trigger lanet: Any system exceeding the detection limit must take one sample every quarter. V the sampling results fall reliably and consistently
below the MCL, the State may reduce the system's sampling frequency for that sampling site to one sample every year (§l41.24(h)(7)].
Muntertng Walvam: Systems granted a monitoring waiver must sample at a frequency specified by the State. The vulnerability asseaiment must be updated
every compliance period (three years) {S141.24(h)(5)J.
Cuntaiaurrts;
Alachkx
AkJicarb
AMicarb Sultadde
Aldicarb Sufone
Atrazine
Benzo(a)pyrene
Carbofuran
Dibromochloropropane
2.4-D
Ethylene Dfbromide
Heptachlor
Undane
Methoxychtor
Pentachkxophenoi
Toxaphene
Z4.5-TP
[PHASE I. SYNTHETC.DOT]
July 7,1801
-------
Standard Monitor ing Framework
UNREGULATED CONTAMINANTS
Sampling Frequencies
YEAR
IOCS
sees
1993
1994
1993
1996
1997
1998
1999
2000
2001
Initial Sampling ; All systems with more than 150 service connections must take one sample for lOCs and four
consecutive quarterly samples for SOCs during the initial compliance period (1993 - 1995).
Monitoring Waivers : Systems granted a monitoring waiver are not required to monitor.
Contaminants : See §141.40(n)(12) for IOCS and §141.40(n)(11) for SOCs.
-------
MONITORING WAIVER GUIDANCE
INTRODUCTION
The entire monitoring waiver guidance package will consist of (1) state primacy guidance, (2) a set of
example waiver application forms and instructions for completing the forms, and (3) a PC diskette with the example
material in either Word Perfect 5.1 or Lotus 2.01 (mostly WP 5.1) along with a written explanation of how States
can customize the forms for their specific needs.
The example Monitoring Waiver Application form and accompanying Instruction Booklet included in this
package are still under development, and many pieces remain to be completed. However, enough of the work has
been completed to provide a rough picture of the approach we're taking. We are very interested in state comments
on our approach. To provide a context for this guidance, we think the following points should be kept in mind.
STATE OPTION ;- The decision to issue monitoring waivers is legally a state option. States may elect to require all
systems to meet the minimum standard monitoring requirements. States wishing to issue waivers may choose to issue
only a certain type of waiver (e.g., "use" waivers) for certain classes of contaminants (e.g., specific pesticides) to certain
types of systems (e.g., small ground water systems).
ECONOMICS & TECHNICAL VALIDITY: If the cost of demonstrating eligibility for a waiver exceeds the savings to
be realized from reduced monitoring costs (a few thousand dollars at most), water systems will be economically better-
off meeting the standard monitoring requirements. But, the design of any vulnerability assessment process must be
technically valid in providing a reasonable margin of assurance that the water supply will not become contaminated
during the term of the waiver. It remains unknown whether such a process can be designed that is inexpensive and
simple enough to make monitoring waivers economically advantageous.
EASY CALLS / TOUGH CALLS: The range of factors that must typically be considered for water systems in highly
populated areas or in complex geological settings will probably prevent the vulnerability assessment process from
being economically advantageous to such systems. Our methods of analysis intentionally exclude the more complex
scenarios that would quickly exceed the economic advantage limit described above. We are focusing the assessment
design at those water systems for which the circumstances affecting vulnerability are simple and easy to analyze. In
short, only the 'easy calls' are likely to find it economically advantageous to apply for a monitoring waiver.
WELLHEAD PROTECTION CONNECTION : If a state Wellhead Protection Program is approved by EPA as pan of a
State's monitoring waiver process, the wellhead analysis undertaken by individual communities may be accepted by
the State to satisfy the monitoring waiver application requirements, assuming that analysis meets the EPA approved
state criteria. In other words, States and individual communities may use wellhead protection programs to achieve
the goals of both programs.
s.
PRIORITIES FOR GUIDANCE DEVELOPMENT : The example application materials in this package are designed for
ground water systems serving less than 3,300 people, which comprise about 75% of the water systems regulated under
the SDWA Depending on state interest, we may later develop guidance for small surface water systems. Such
guidance would also be focused at the 'easy call* situations, rather than describe how to perform a detailed analysis
for entire watersheds.
-------
STATE DEPARTOOIT OF NATURAL RESOURCES
Monitoring Waiver Application
for
Small Ground Water Systems
Public Water Systems (PWSs) are required to monitor for certain types of contaminants. Using this form, PWSs can apply
for waivers from requirements to monitor for pesticides and volatile organic compounds. Please read the Introduction and
General Instructions in the Instruction Booklet for an explanation of these waivers, and the purpose of this form. If you wish
to apply for a monitoring waiver, complete all the information requested in this form. Do not sign the signature block until you
have completed everything else.
I I I i i i
Name of Public Water System (PWS) PWS Identification Number
Name of Responsible Official Title
(_ L
Street Address of PWS Telephone Number, including Area Code
City or Town: State: ZIP Code County
Has your PWS worked in cooperation with the State's Department of Natural Resources to develop a Wellhead Protection
Program for the PWS?
_ Yes
No
SIGNATURE BLOCK
\.
I certify the information in this monitoring waiver application is complete and accurate, to the best of my knowledge.
Signature of Responsible Official Data
Name and TO. of Cerffytno; Official (» «»roe m f*K>on*U» Official Inted above, put -Mine-.)
-------
PART t: CONTAMINANTS & TYPES OF WAMERS fa.
1 . CONTAMINANTS: Complete column 1 of Table A. List each of the contaminants or contaminant categories from which you wish to
receive a monitoring waiver. Refer to Exhibit AA on page _ of the Instruction Booklet for important information about contaminants
and the cost of analytical methods.
2. WAIVER TYPES : Complete column 2 of Table A. For each contaminant, identify the type of waiver you are seeking. Refer to
the General Instructions of the Instruction Booklet for more information about the two types of waivers.
•USE- WAIVBI •SUSCBTlBIUTr WAIVER
To qualify for a 'use' waiver, you must show that the contaminant has To qualify for a "susceptibility* waiver, you must show that although the
not been used around your water supply. If the contaminant has ever contaminant may have been used in the area around your water supply:
been detected in your water supply or in the supply of a neighboring (1) it has not been detected, and (2) the supply is so well pmtacted that
system, you cannot be granted a •use- waiver. it is very unlikely to become contaminated during the term of the waiver.
To receive a "use* waiver, you must provide the information requested To receive a "susceptibility" waiver, you must provide the information
in Parts I - V and complete Table A and columns 1 and 2 of Table B. requested in Parts I - VII and complete Tables A and Table &
PART II : DETECTION OF CONTAMINANTS rm
3. CONTAMINANT DETECTION DATA: Complete columns 3A and 3B of Table A. If any of the contaminants for which you are seeking
a waiver have ever been detected in your water system, you must answer "yes* for that contaminant in Column 3A. If you know
of the detection of any contaminants in neighboring water systems, you must answer "yes" in Column 3B. Only if you are certain
that the contaminants for which your are seeking a waiver have not been detected in a neighboring water system, may you
answer 'no' in Column 38. See page of the Instruction Booklet for additional guidance on completing this part of the form.
4. MONITORING DATA SUMMARY: Provide a summary of previous monitoring data for your system, and as required, for neighboring
systems. ( Refer to pages _ - _ of the Instruction Booklet for guidance on this part of Table A, and pages _ - _ for guidance
on summary monitoring data )
IP/^:^
5. LOCATION OF WELLS: Attach a map of your water system and its surrounding area The best map is a U.S. Geological Survey
topographic map, which costs $2.50. You may use a local street map, or any map that is accurate and legible. On the map,
show the location of each well and label each well with a unique number. See page _ of the Instruction Booklet for more
information.
6. AREA OF DELINEATION : Consult the Instruction Booklet for an explanation of delineated areas and to decide which method is
best for you. Several easy methods for determining an Area of Delineation are available. Indicate which method you will use
for your system:
_ Method W: Part of a Well Head Protection Program approved by EPA for use in monitoring waiver decisions
_ Method X: State Designed Fixed Radius Circle
_ Method Y: Calculated Radius Circle (Complete items #7 and #8 under PART IV : GEOLOGICAL DATA in order
to implement this method.)
_ Method Z: Other Method - provide complete documentation
Determine an Area of Delineation surrounding each of your wells, and draw it on the map. Make sure each delineated area is
legible. The delineated areas must include land which, if contaminated, would be likely to contaminate your water supply during
the term of the waiver.
i -
-------
PART IV: GEOLOGICAL DATA *».
[NOTE: You MUST complete this part, if you checked 'Method Y" or "Method Z" in Item 4 above. Otherwise, you may skip this part and
proceed directly to PART V: LAND USE ANALYSIS.]
7. PUMPING RATES : Complete Columns 1 and 2 of Table B for each well that supplies your water system, even if it is used for
only part of the year. (pp. _ - _ Instruction Booklet)
8. PREVALENT GEOLOGY: Identify the prevalent type of geology in which the intakes of your wells are located. Check only ONE,
even if your system is supplied by more than one well (p. _ , Instruction Booklet).
_ Sand and Gravel _ Karst
_ Bedrock _ Weathered Rock (Saprolite)
_ Unknown _ Glacial Till
_ Silty Sand
PART V : USE OF CONTAMINANTS [P.
9. LAUD Use ANALYSIS: In Column 4 of Table A, indicate whether any of the contaminants for which you are seeking a waiver have
been used within the Area of Delineation, i.e.. .the areas you have designated on the map. Before filling out Column 4 of Table
A, you MUST consult certain types of standard data sources; see pages _ - _ of the Instruction Booklet. In Column 5 of Table
A, document each of the standard data sources you consulted, and attach a list of any other data sources you consulted.
PART VI : SOURCE WATER SUSCEPTIBILITY
10. WEIL CONSTRUCTION DATA : Complete Columns 3 through 7 of Table B. The table is self-explanatory; (pp. _ - _ , Instruction
Booklet)
1 1 . Son. TYPES : Identify the types of soil in which your wells are located. See pp. _ - _ , Instruction Booklet for descriptions of
each of each soil type and directions for contacting the Soil Conservation Service representative in your area. The SCS can help
you complete this item.)
Texture of Texture of
Surface Soil Subsoil
_ _ Non-shrinking and non-aggregated clay
_ _ Clay loam
_ _ Muck
_ _ Silty loam
_ _ Loam
' _ _ Sandy loam
_ _ Shrinking or aggregated clay
, _ _ , Peat
_ _ Sand
_ _ Gravel
Thin or absent
- 2 -
-------
PART VII ; SOURCES or POTENTIAL CONTAMINATION fa
12. LOCATION OF POTENTIAL CONTAMINATION Srres : Locale all contamination sources within your Areas of Delineation. Table _,
p._, Instruction Booklet lists potential contamination sources by contaminant. You must consult this table to determine which
potential contamination sources associated with the contaminants for which you a seeking a waiver are located within your Areas
of Delineation. Identify their location on the map by using the two-letter code representing that type of source. Some
contamination sources are •point' sources (e.g., industrial facilities) and others are "non-point* sources (e.g., agricultural
application of a pesticide). See the Instruction Booklet for information on how to mark contamination sources (e.g., how to mark
the location of an industrial facility; how to indicate a land use activity, such as different types of agricultural activity).
If you identified any contamination sources, you must complete Item 10. Otherwise, you may skip Item 10.
13. RISK MmGATTON : Explain how the potential for contamination of your water supply is reduced by current activities and
management practices. For examples, see pp. _ - _, Instruction Booklet.
3 -
-------
t. v
/•
1
Contaminants for Which You are
Seeking a Monitoring Waiver
(On each row, list one category
of contaminants' OR an
Individual contaminant.)
x
I
2
Which Type of
Waiver are You
Seeking?
(Check one only in
each row.)
D "Use"
D "Susceptibility"
D "Use"
D "Susceptibility"
D "Use"
D "Susceptibility"
n "Use-
CD "Susceptibility"
D "Use-
Hi] "Susceptibility"
D "Use"
D "Susceptibility"
3
Have These Contaminants Been
Detected in Previous Monitoring...
A.
...in your PWS?
DYes
DNo
DYes
D No
D Yes
D No
DYes
CD No
a Yes
D No
DYes
DNo
B.
...in an adjacent
PWS?
CD Yes _„ .
QNo D ""known
DYes _,
QNo D Unknown
DYes ,_,„.
nNo D Unknown
ONo8 D Unknown
DYes _
ONo a Unknown
DYes
Q No D Unknown
4
Was this contaminant (or any
contaminant in this category) ever
used in the Area of Delineation?
(See page of the Instruction
Booklet for definition of "use.")
YES NO UNKNOWN
D D D
D D D
D D D
D D D
D D D
D D D
5
List the reference code(s) for
the standard data sources
you consulted for column 4.
These codes are provided on
page of the Instruction
Booklet. If you consulted
additional data sources,
attach a list of these sources.
01
0>
• II you need more rows, use the continuation of this table, which is provided in Attachment B.
Table B: Data on Wells that Supply this PWS*
1
Well*
(Must
correspond to
numbers on map
in Attachment A.)
h
2
Safe Yield Pumping Rate
(See instructions on page . List the
rate, in gallons per day. If the rate is
unknown, list "?".)
Gallons per day
Gallons per day
Gallons per day
Gallons per day
3
Well depth
(in feet).
4
Depth to water
table (highest
measured
elevation).
5
Year well was
constructed.
6
Constructed
using welded
steel casing?
7
Casing cement grouted?
(If "yes." to what depth?)
D Yes D No
If "yes.* to what depth? feet
D Yes D No
If "yes * to what depth? feet
D Yes D No
II "yes," to what depth? Iccl
D Yes D No
If "yes " to what depth? feel
tf (his PWS has more than 4 wells, use the continuation of this table, which la provided in Attachment B.
P..I
-------
Wednesday
January 30, 1991
Part II
Environmental
Protection Agency
40 CFR Parts 141, 142, and 143
National Primary Drinking Water
Regulations; Final Rule
-------
/ Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
EMVIROMMEWTAL PROTECTION
AGENCY
40 CFR Parto 141, 142. and 143
[WH-FRL-3380-1]
National Primary Drinking Water
Rogulatteno—Synthetle Organic
Chemicals and Inorganic Chemicals;
Monitoring «or Unregulated
Contaminants; National Primary
Drinking Water Regulations
ImptQcnentatlon; National Secondary
Drinking Water Regulations
v: U.S. Environmental Protection
Agency (EPA).
ACTION: Final rule.
SUMMARY: By this document. EPA is
promulgating maximum contaminant
level goals (MCLGs) and National
Primary Drinking Water Regulations
(NPDWRs) for 26 synthetic organic
chemicals (SOCs) and 7 inorganic
chemicals (IOCs). (The MCLGs and
MCLs for aldicarb, aldicarb sulfoxide,
aldicarb sulfone, pentachlorophenol and
barium are reproposed elsewhere in
today's Federal Register due to changes
in the health basis for the MCLGs and/
or revised MCLs.) The NPDWRs consist
of maximum contaminant levels (MCLs)
or treatment techniques for the SOCs
and IOCs. The NPDWRs also include
monitoring, reporting, and public
notification requirements for these
compounds. This document includes the
best available technology (BAT) upon
which the MCLs are based and the BAT
for the purpose of issuing variances. The
Agency is promulgating secondary
MCLs (SMCLs) for two contaminants
and one-time monitoring requirements
for approximately 30 SOCs and IOCs
that are not regulated by NPDWRs.
EFFECTIVE SATE: All sections (141.11.
141.23. 141.24. 141.32. 141.40. 141.50,
141.60, 141.61. 141.62. 141.110. 141.111.
142.14, 142.15, 142.16, 142.57. 142.62.
142.64, 143.3. and 143.4) of this regulation
are effective July 30. 1392. The
information collection requirements of
§ 1 141.23. 141.24 and 141.40 are effective
July 30. 1992 if the Information
Collection Request is cleared by the
Office of Management and Budget
(OMB). If not. the requirements will be
effective when OMB clears the request
at which time a document will be
published in the Federal Rogioto?
establishing the effective date. In
accordance with 40 CFR 23.7. this
regulation shall be considered final
Agency action for the purposes of
judicial review at 1 p.m.. Eastern time on
February 13. 1S91.
AB0RE88S3: A copy of the public
comments received. EPA responses, and
all other supporting documents
(including references included in this
notice) are available for review at the
U.S. Environmental Protection Agency
(EPA), Drinking Water Docket, 401 M
Street, SW., Washington. DC. 20460. For
access to the docket materials, call 202-
3S2-3027 between 9 a.m. and 3:30 p.m.
Any document referenced by an MRID
number is available by contacting Susan
Laurence, Freedom of Information
Office, Office of Pesticide Programs, at
703-557-4454.
Copies of health criteria, analytical
methods, and regulatory impact analysis
documents are available for a fee from
the National Technical Information
Service (NTIS), U.S. Department of
Commerce, 5285 Port Royal Road.
Springfield. Virginia 22161. The toll-free
number is 800-336-4700, local: 703-487-
4650.
FOB FURTHER ONFOBtaAVIOKI (B@MYACY: Al
Havinga, Criteria and Standards
Division, Office of Drinking Water
(WH-550), U.S. Environmental
Protection Agency, 401M Street, SW..
Washington. DC 20460, 202-382-5555. or
one of the EPA Regional Office contacts
listed below. General information may
also be obtained from the EPA Drinking
Water Hotline. The toll-free number is
800-426-4791, local: 202-382-5533.
EPA Regional Officoo
I. JFK Federal Bldg.. room 2203. Boston. MA
02203, Phone: (817) 565-3602. Jerry Healey
Q. 29 Federal Plasa. room 824. New York, NY
10273. Phone: (212) 264-1800, Walter
Andrews
in. Ml Chestnut Street, Philadelphia. PA
19107. Phone: (215) 597-8227, Jon Capacaoe
IV. 345 Courtland Street. Atlanta. CA 30395.
Phone: (400) 347-2913, Allen Antley
V. 230 S. Dearborn Street. Chicago, IL 80804.
Phone: (312) 353-2152, Ed Walters
VI. 1445 ROOD Avenue, Dallao. TX 75202.
Phone: (214) 255-7155. Tom Love
VII. 728 Minnesota Ave.. Kannao City. KS
88201. Phone: (913) 551-7032, Ralph
Langemeier
VITJ. One Denver Place. 9S918th Street, ouite
300, Denver, CO 80202-2413, Phone: (303)
293-1408, Patrick Crotty
IX. 215 Fremont Street San Francisco. CA
84105. Phone: (415) 974-0912. Steve
Pardieck
X. 1200 Sixth Avenue. Ssattle. WA 08101.
Phone: (203) 442-5092, Jan Haotingo
AWhsoviatiosno Uocd ia TWo Ossamont
AA: Direct Aopiration Atomic Absorption
Spectroocopy
ADI Adjuotod Daily Intake
BAT: Baot Available Technology
BTCA: Beot Technology Gensrally Available
CAA: Clean Air Act
GAG: Cancer Aoosooment Croup
CRAVE: Cancer Riotc Aooeooment
Verification Endeavor
CUR: Carbon Usage Rate
CWS: Community Water System
DWEL: Drinking Water Equivalent Level
EBCT: Empty Bed Contact Time
ED: Electrodialyoio
EDR: Electrodialysis Reversal
EMSL: EPA Environmental Monitoring and
Support Laboratory (Cincinnati)
FraHA: Farmer's Home Administration
GAC: Granular Activated Carbon
GFAA: Graphite Furnace Atomic Absorption
Spectroscopy
ICP-AES: Inductively Coupled Plasma-
Atomic Emission Spectroscopy
IE: Ion Exchange
1MDL: Inter-Laboratory Method Detection
Limit
IOC: Inorganic Chemical
LOAEL: Lowest-Observed-Adverse-Effect
Level
LOQ: Limit of Quantitation
MBS: Multinational Business Services, Inc.
MCL Maximum Contaminant Level
(expressed as mg/1) '
MCLG: Maximum Contaminant Level Coal
MDL: Method Detection Limit
MGD: Million Gallons per Day
NAS: National Academy of Science
NEPDWR: National Interim Primary Drinking
Water Regulation
MIST: National Institute of Standards and
Technology
NOAEL: No-Observed-Adverse-Effect Level
NORS: National Organic Reconnaissance
Survey
NPDWR: National Primary Drinking Water
Regulation
NSF: National Sanitation Foundation
NTWS: Non-Tranaient Non-Community
Water System
OPP: EPA'o Office of Pesticide Programs
PAP: Polymer Addition Practices
PE: Performance Evaluation
POE: Point-of-Entry Technologies
POU: Point-of-Use Technologies
PQL: Practical Quantitation Level
PTA: Packed Toxver Aeration
PWS: Public Water System
RID: Reference Dose (formerly termed .
Acceptable Daily Intake (ADI))
RIA: Regulatory Impact Analysis
RMCL: Recommended Maximum
Contaminant Level
RO: Reverse Osmosis
RSC: Relative Source Contribution
SOW A: Safe Drinking Water Act, or the
"Act" as amended in 1983
SMCL: Secondary Maximum Contaminant
Level
SOC: Synthetic Organic Chemical
TEM: Transmission Electron Microscopy
THMo: Triholomethenea
TON: Total Odor Number
TWS: Transient Non-Community Water
System
UF: Uncertainty Factor
UIC: Underground Injection Control
VOC: Volatile Organic Chemical
WHP: Wellhead Protection
Tabla 1 — MCLGo and MCLo for Inorganic
ttn Bain/an tn
11.C03 mlcrogromo (jig) = 1 milligram (mg).
-------
Federal Register / VoL 56, No. 20 / Wednesday. January 30. 1991 / Rcles and Regulations 3527
Table 2—MCLC* and MCLs for Volatile
Organic Contaminants
Table 3—MCLGs and MCLs for Pesticides/
PCBs
Table 4—MCLGs and Treatment Technique
Requirements for Other Organic
Contaminanta
Table 5—Secondary Maximum Contaminant
Levels (SMCL*)
Table 6—Best Available Technologies to
Remove Inorganic Contaminants
Table 7—Best Available Technologies to
Remove Synthetic Organic Contaminant*
Table 8—Compliance Monitoring
Requirements
Table 9—Analytical Methods for Inorganic
Chemicals
Table 10—Analytical Methods for Volatile
Organic Chemicals
Table 11—Analytical Methods for Pesticide*/
PCBs
Table 1Z—Laboratory Certification Criteria
Table 13—State Implementation
fi c^tnrtnrcTTtt
Table 14—EPA's Three Category Approach
for Establishing MCLGs
Table IS—Relative Source Contribution
Table 16—Inorganic Contaminant
Acceptance Limits and Practical
Quantification Levels
Table 17 IiioigaiDC Cuiituiiiiijdiit Sample
Preservation, Container, and Holding Time
Requirements
Table 18—Pesticide/PCB Practical
Quantitaiion Levels and Acceptance Limits
Table 19—Qectrodialysis Performance
Compared to Proposed BATs
Table 20—Additional Costs for Vepor Phase
Carbon Emission Controls for Packed
Tower Aeration Facility
Table 21—GAC and Packed Column Costs to
Remove SOCs
Table 22—MCL Analysis for Category I SOCs
Table 23—MCL Analysis for Category D and
in SOCs
Table 24—Method Detection Limits—
Pesticides/PCBs
Table 25—Unregulated Inorganic and
Organic Contaminants
Table 26—Section 1415 BAT for Inorganic
Contaminants
Table 27—Section 1415 BAT for Organic
Contaminants
Table 28—Summary Impact Estimates for
Final IOC and SOC Regulations
Table 29—Comparison of Total Annualized
Costs for Proposed and Final Rules
Table 30—Upper Bound Household Costs ($/
HH/year)
SUPPLEMENTARY INFORMATION:
Abbreviations Used In This Document
LUt of Tables
Table of Contacts
L Summary of Today's Action
D. Background
A. Statutory Authority
B. Regulatory History
C Public Comments on the Proposal
EL Explanation of Today's Action
A. Establishment of MCLGs
1. How MCLGs Are Developed
2. Response to Comments on EPA's Zero
MCLG Policy
3. Relative Source Contribution
4. Inorganic MCLGs
a. Asbestos
b. Cadmium
c. Chromium
d. Mercury
e. Nitrate/Nitrite
'(1) Nitrates and Cancer
(2) Other Effects
(3) Other Issues
f. Selenium
5. Volatile Organic Contaminants (VOCs)
MCLGs
a. cis-U-Dichlorocthylene and trans-L2-
Dichloroethylens'
b. 1.2-Dichloropropane
c. Ethylbenzene
d* Monocnloiube^L&eiie
e. ortho-DichtcTobenzene
f. Styrene
g. Tetrachloroethylene
h. Toluene
i. Xylenes
6. Pesticides/PCBs MCLGs
a. Alachlor
b. Atiaiiue
c. Carbofuran
d. Chlordane
e. 1 J-Dibromo-3-chlcropropane (DBCP)
12.4-D
g, Heptachlor/Heptachlor Epoxide
h. Lindane
L Methoxychlor
). Polychlortnated Biphenyls (PCBs)
7. Other Synthetic Organic Contaminant
MCLGs
•. Acrylamide
B. Establishment of MCLs
1. Methodology for Determination of MCLs
2, Inorganic Analytical Methods
a. Asbestos
b. Nitrate/Nitrite
c. Other Inorganic Analyses
d. Method Detection Limits and Practical
Quantification Level
(1) Inorganics
(2) Nitrite
e. Inorganic Chemical Sample Preservation,
Container, and Holding Time
3. SOC Analytical Methods
a. VOC Methods
b. Method Availability
c. Cleanup Procedures
d. Pesticide Methods
e. Method 525
f. PCB Analytical Methods
g. VOC Performance Studies
b, Pesticide/PCB PQL and Performance
Acceptance Limits
4. Selection of Best Available Technology
a. Inorganics
b. Synthetic Organic Contaminants
(1) Why PTA Is BAT far Air Stripping
(2) PTA and Air Emissions
(3) BAT Field Evaluations
(4) Carbon Disposal Costs
(5) Powdered Activated Carbon eo BAT
(6) Empty Bed Contact Time
(7) Carbon Usage Rates
5. Determination of MCLs (Feasibility and
Cost)
a. Inorganic Contaminant MCLs
b. Synthetic Organic Contaminant MCLs
(1) Category I Contaminants
(2) Category U and in Contaminants
C Treatment Technique Requirements
D. Compliance Monitoring Requirements
1. Introduction
2. Effective Date
3. Standard Monitoring Framework
a. Three-, Six-. Nine-Year Cycles
b. Base Monitoring Requirements
c. Eight VOCs Regulated July 8,1987
d. Increased Monitoring
e. Decreased Monitoring
f. Vulnerability Assessments
g. Relation to the Wellhead Protection
Program
h. Initial and Repeat B*»e Monitoring
4. Monitoring Frequencies
a. Inorganics
(1) Initial and Repeat Base Requirements
(2) Increased Monitoring
(3) Decreased Monitoring
b. Asbestos
(1) Initial and Repeat Base Requirements
(2) Increased Monitoring
(3) Decreased Monitoring
c. Nitrate
(1) Initial and Repeat Base Requirements
(A) Community and Non-Transient
Water Systems
(B) Transient Non-Community Water
Systems
(2) Increeaed Monitoring (CWS, NTWS.
TWS)
(3) Decreased Monitoring (Surface CWS
and NTWS)
d. Nitrite
(1) Initial and Repeat Ba*e Requirements
e. Volatile Organic Contaminants (VOCs)
(1) Initial enri Repeat Base Requirements
(2) Incrsajed Monitoring
(3) Decreased Monitoring
f.Pesticid2s'PCB»
(1) Initial and Repeat Base Requirements
(2) Incrscseu Monitoring
(3) Decreased Monitoring
5. Other Issue?
a. Compliance Determinations
b. Confirmation Samples
c. Corr.posiLr.j
d. Asbestos
6. Uaregu.«:ad Csniamimnt Monitoring
E. Variances and Exemptions
1. Variant.)
2. Point-c; J.'«e Devices. Bottled Water, and
Poir.t-of-E:.try Devices
3. Exemptions
F. Laboratory Certification
G. Public Notice Requirements
1. General Cocuneais
2. Cor.tomtr.ar.;-Specific Comments
a. Asbestcs
b. Other Con:arninants
H. Secondary MCLs
1. Organics
2. Aluminum
3. Silver
a. Deriva-.icn of SMCL for Silver
I. State Implementation
1. Special State Primacy Requirements
2. State Recordkeepir.? Requirements
3. State Reporting Requirements
IV. Economic Analysis
A. Cost of Final Rule
B. Comparison to Proposed Rule
1. Monitoring Requirements
2. Changes in MCLs
3. Changes in Occurrence Data
4. Changes in Unit Treatment Cost
Estimates
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3528 Federal Register / Vol. 56. No. 20 / Wednesday. January 30, 1991 / Rules and Regulations
C. Coat to Systems
D. Cost to State Programs
V. Other Requirements
A. Regulatory Flexibility Analysis
B. Paperwork Reduction Act
VI. Public Docket and References
I. Summary of Today's Action
The effective date of this rule is July
30.1992.
TABLE 1.—MCLGs AND MCLs FOR INORGANIC CONTAMINANTS
(1) Asbestos ._ .
(2) Cadmium
(3) Chromium
(4) Mercury - _ ... __..„.
(5) Nitrate _
(6) Nitrite
(7) Total Nitrate and Nitrite
(8) Selenium
MCLGs
7 million fibers/liter (longer than 10 pm)
0 005 mg/l
0 1 mg/l ~ ~
0 002 mg/l _ . . __ .
10 mg/l (at N)
1 mg/l (as N)
10 mg/l (as N).... - .. ..
005 mg/l
MCLs
7 million fibers/liter (longer than 10 pm)
0 005 mg/l
0 1 mg/L
0 002 mg/L
10 mg/l (as N)
1 mg/l (as N)
10 mg/l (as N)
0 05 mg/L
TABLE 2.—MCLGs AND MCLs FOR
VOLATILE ORGANIC CONTAMINANTS
TABLE 3.—MCLGs AND MCLs FOR
PESTICIDES/PCBS
(1) o-Oichkxobenzene....
(2)6s-1.2-
Dehtoroethylene
(3) trans-1.2-
CSchkxoetnytene
(4) U-Oichloropropane .
(5) Ethytbenzene
(6)
Monochlorobenzene ....
(7) Styrene
(8) Tetrachloroethylene..
(9) Toluene
(10) Xytenes (total)
MCLGs
(mg/l)
0.6
0.07
0.1
0
0 7
0.1
0.1
0
1
10
MCLs (mg/
0
0.6
0.07
0.1
0.005
07
0.1
0.1
0.005
1
10
(1) Alachlor . _.
(2) Atrazine
(3) Carbofurtn —
(4) Chlordane
(5) 1 i-Oibromo-3-
chkxopropane (CBCP).
(6) 2 4-O
(7) Ethytene dibromide
(EBB).
(8) Heptachlor _.
(9) Heptachlor epoxxle ....
(10) Lindana
(11) Memoxychlor.
(12) Porychtorinated
biphenyls (PCBs) (as
decachtorobiphenyl).
(13) Toxaphene _
(14) 2.4,5-TP (Silvex)
MCLGs
Zero
0.003 mg/l
0.04 mg/l
Zero
Zero
0 07 mg/l
Zero
Zero
Zero
0.0002 mg/l
0.04 mg/l —
Zero
Zero
0.05 mg/l
MCLs
(mg/l)
0002.
0.003.
0.04.
0002
00002
007I/
L
0.00005.
0.0004.
0.0002.
0.0002.
0.04.
0.0005.
0.003.
0.05.
TABLE 4.—MCLGs AND TREATMENT
TECHNIQUE REQUIREMENTS FOR OTHER
ORGANIC CONTAMINANTS
(1) Actylamide —
(2) Epichlorohydrin ....
MCLGs
Zero
Zero
MCLs
Treatment
tecnniQueL
Treatment
technique.
TABLE 5.—SECONDARY MAXIMUM
CONTAMINANT LEVELS (SMCLs)
(1) Aluminum „ 1 0.05 to 0.2 mg/L
(2) Silver _ _.. 0.1 mg/1.
TABLE 6.—BEST AVAILABLE TECHNOLOGIES TO REMOVE INORGANIC CONTAMINANTS
Best available technologies
inorganic
contami-
nant
Asbestos ...
Barium
Cadmium ...
CtWOfniurn
hi.
Chromium
VI.
Mercury
Nitrate
Nitrite
Selenium
IV
(Sele-
nrte).
Selenium
VI
(Sele-
nate).
Activated
alumina
X
X
Coagulation/
filtration '
X
X
X
X
X1
X
Corrosion
control
X
Direct
filtration
X
Dlatomna
filtration
X
Granular
activated
carbon
X
Ion
exchange
X
X
X
X
X
X
X
Lime
softening1
X
X
X
X '
X
X
Reverse
osmosis
X
X
X
X
X1
X
X
X
X
Electro-
diotysis
X
X
X
1 BAT only If influent mercury concentrations do not exceed 10 fig/L Coagulation/filtration lor mercury removal includes PAC addition or post-fi!traOon GAC
column where high organc mercury m present in source water.
1 Not ' <15 BAT for small system* tor variances unless treatment is currently in place.
-------
Federal Register / Vol. 56. No.'20 / 'Wednesday,'January 30. 1991. / Rules and' Regulations 3529
TABLE 7.—BEST AVAILABLE TECHNOLOGIES TO REMOVE SYNTHETIC ORGANIC CONTAMINANTS
' '• " • Chemoaf
VCCr
da 1.J DMitauaDiytm*
•*ne 1J, OtMorotlriytto*
Ethytt" ITTH
Sturana ulr*T1"T™
Ttuai.tHiiiuiiir.'ii'it
Tohttnt
Xytenes (Total)
AlacNor
Akflcvt> euNone
AtraUnt
Chtorden*
psyompghtofapiuparn (OBCP)
U^f^^j+^ur
Undent
PentacMorophenal
245-TP (Sffvex)
FlUThlrimJ^jljt
GAC>
x
X
x
x
x
x
x
x
x
x
x
x
x
X
x
x
X
X
X
x
x
x
x
x
x
x
PTA«
x
x
x
x
x
x
x
x
x
X
X
X
PAP*
x
X
' GAC - Granular activated carbon.
• PTA - Pecked tower aeration.
•PAP - I
TABLE 8.—COMPLIANCE MONITORING REQUIREMENTS
wUfPUsHaWeVIl
-'
.
NitnU
10 VOG»
IB PflStcMWk/PC&t
Unregulated:
-6 IOCS, -24 SOCs
Bees requirement
Ground weter Surface mater
1 sample/a yr Annual sample
Annual Quarterly
Alter 1 year 3.300 reduce to 2 samptee/yr
•very 3 yrs. systems O.300 reduce to 1 sample
•very 3 yrs.
One sample, 4 consecutive fflterterB —
-MH
>50*f MCI .,.,„
>SO% MCL .„
Detection, (see Table 23)
Waivers
Yer
3r
Yea:
rm
No.
No.
Yes:
mi
Yes:
im
Yea:
m
Based on analytical results of
ounds.
Based on vulnerability assess-
nt
Based on vulnerabUity assess-
nt
Based on vulnerability assess-
mt
Based on vulnerability assess-
mt
Table B.—Analytical Methods for
Inorganic f-homir^lf
Contaminant and Methodology
Aluminum;
Atomic absorption: furnace technique '
1 Graphite Punuc* Atomic Absorption
Spectmcopy (CPAA).
Atomic absorption, direct aspire don *
Asbestos
Transmission electron microscopy
Barium:
Atomic absorption: furnace technique *
Atomic absorption: direct aspiration *
' Direct Aspiration Atomic ADMITition
Spectrotcopy (AA).
Inductively coupled plasma /3/
Cftdmiunr
Atomic absorption; furnace technique
Inductively coupled plasma *
Chromium:
Atomic absorption: furnace technique '
Inductively coupled plasma *
Mercury:
• Inductively Coupled Pl«im»—Atomic' Eminion.
SpectroKOpy (1CP-AES).
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353® radar®! l&BjpotB? / Vol. 56, No. 20 / Wednesday. January 30. 1S91 / Rules and regulations
Manual cold vapor techique
Automated cold vapor technique
Nitrate:
Manual cadmium reduction
Automated hydrazine reduction
Automated cadmium reduction
Ion oelective electrode
Ion chromotography
Nitrite:
Spectrophotometric
Automated cadmium reduction
Manual cadmium reduction
Ion chromatography
Selenium:
Atomic absorption: gaseous hydnde
Atomic absorption: furnace '
Silver
Atomic absorption: direct aspiration '
Inductively coupled plasma *
TABLE 10.—ANALYTICAL METHODS FOR
VOLATILE ORGANIC CHEMICALS
EPA rrrathods
Contaminants
Styrono.
TstrccRloroatnytena.
Toluene.
Xytonas.
TABLE 11 .—ANALYTICAL METHODS FOR
PESTICIDES/PCBS
EPA mathoda
Contaminants
504.
SOS.
507..
503.
EBiyJcno fiibrcmida
Atasfcto.
Atraano.
Chtordans.
Mcpscsftto.
Heptacnta cjffltsda.
Undarto.
Molnojiycntei.
Toaopftsno.
PCBo'
AlCttltOf.
Atrozino.
Chtartlano.
Hcpjccntor cjHBEda.
LcaScro.
PCBo'
508A I PCBo (oo decachtorcbipnonyl).
515.1 | 2.4-O.
2AS-TP «SE»aJ.
525 i
531.1.
Ateehlor.
Atrozino.
CWoroano.
Lmdana
Ccr&ofurcn.
TABLE 12.—LABORATORY CERIT«FICATION
CRITERIA
. (OCo:
RtJOfida
WJtTQlO
NiirQe
i VOCsr
bocod on otuoy statis-
tics
±15% at >0.1S mg/l
*20% Qt >. 002 mg/l
±15% at >0.01 mg/l
±10% at 1 to 10 mg/l
±30% Qt > 0.0003 mg/1
±10% Qt >0.4 mg/l
±15% at >04 mg/l
±20% at >001 mg/l
502.1 .._ ..... ------- j o-DichtoJobanzens.
502.2 ..... ---- ....... oo-li-DJchtoiDsthytena.
503.1 ----- ...... — j Irano-I.a.-Dichtomathytena.
524.1 ----------- 1 l,2-Oich!cropnjpan3.
524.2 ................... | Ethylbsnzcno.
1 Motticdo 505 and 308 era iced ao ceccno «n^.
If dejected bi 505 or 503. cyacsn one!
ueng Rtothoa 50BA,
Pirotiadoa and PCBo:
AlcchKtr
Atrozin3..._ _
Corbofuran _
Hejflecfilex
Undano ...... _ .....
PCBo (as
DcccchtaroSi-
pftcnyt).
Akfeorb ........ ___
Aktcorb cutlorado ..
AkJxarb suttono
Tosapftono .............
2.4-O ___ ........
2.4.S-TP ....... ____
HJ3 ..... _ ......... _
CBCP ........... _
±20% at >0.010 mg/l
±40% Qt <0.010 mg/l
±45% at 0 002 mg/l
±45% ai 0.001 mg/l
±45% Qt 0.007 mg/l
±45% at 0.002 mg/1
±45% at 0.0004 fng/1
±45% Qt 0.0002 mg/l
±45% Qt 0.0002 mg/1
±45% at 0.01 mg/l
0-200% at O.OC55 mg/l
±55% at 0.003 mg/l
±55% at 0.003 mg/1
±55% at 0.603 Rtg/l
±45% at 0.003 mg/t
±50% at 0.001 mg/l
±50% at 0.005 fng/l
±50% at 0.005
±cesi m O.OOOO3
±40% at 0.0002 mg/l
TABLE 13.—STATE IMPLEMENTATION
REQUIREMENTS
' R«ju»cd if Statoo gram WOWOTO.
j II
i
j A. Statutory Authority
| The Safe Drinking Water Act (SLTWA
or "the Act"), ao amended in 1986 (Pub.
L No. 62-338, 100 Slat. 042), requires
EPA to publish "maximum contaminant
level goals" (MCLGs) for contaminants
which, in the judgment of the
Administrator, "may have aa adverse
effect on the health of persons and
[ Rc«ju>omcAJ
i
| VulnerateSty
• ascoccmsnl
j p?OQ*&ii\00 '.
i Wowcr
1 pxocw&iAvO.
'. MoreSorotg
\ ocfc*jJo.
| Vutncrateisy
' osococmsnt
1 dstcnjaa-
j tiara.
! Woworo granted..
Tfoasiiora
tecnrasuo
ccrtrticationo.
; Unregulated
i contflironQ/rt
1 results.
i
Primacy
X
X
X
^c^oro-
ticcp^tg
X
X
X
K
Reporting
X
which (are) known or anticipated to
occur in public water systems" (section
1412(b;(3)(A)). MCLGs are to be set al a
level at which "no known or anticipated
adverse effects on the health of persons
occur and which allows an adequate
margin of safety" (section 1412fb)(4)J.
At the same time EPA publishes an
MCLG. which is a non-enforceable
health goal, it must also promulgate a
National Primary Drinking Water
Regulation (NPDWR) which includes
either (l) a maximum contaminant level
(MCL), or (2) a required treatment
technique (section 1«01(1), 1412f a)(3).
and 1412(b)(7)[A]). A treatment
technique may be set only if it is mot
"economically or technologically
feasible" to ascertain the level of a
contaminant (sections 1401(1) and
1412(b)(7)(A)). An MCL must bs oet ao
dose to the MCLG as feasible (section
1412(b)(4)). Under the Act. "feasible"
means "feasible with the use of the best
technology, treatment techniques, ood
other means which the Administrate?
finds, after examination for efficacy
under field conditions and not solely
under laboratory conditions, are
available (taking coot into
consideration)" (section l«12(b)(5)). !n
setting MCLs. EPA coBoidejro the cost of
treatment technology to large public
water systems (i.e.. > 1.080.000 people)
with relatively clean source water
supplies (132 Cong. Rec. S62S7 (daily
ed.. May 21.1989)). Each NPDWR that
e&Sablishao en MCL rauat liot the best
available technology, treatment
techniques, and other means that are
feasible for meeting the MCL (BAT)
fraction Mt2(b)(8)). NPDWRs include
monitoring, analytical and quality
assurance requirements, specifically,
"criteria and procedures to assure a
supply of drinking water which
dependably complies with such
maximum contaminant levels ° ° °."
(Section fr£Gl(l)(D)). Section 1445 also
airthorizeQ EPA to promulgate
monitoring requirements.
Ssetiora M14(c) requires each owner or
opsraSo? o£ a public water system to
give notice to persons served by it of (1)
any failure to comply with a maximum
contaminant level, treatment technique.
or testing procedure required by a
NPDWR; (2) any failure to comply with
any monitoring required pursuant to
section 1445 of the Art; (3) the existence
of a variance or exemption; and (4) any
failure to comply with the requirements
of any schedule prescribed pursuant t j a
variance or exemption.
Under the 1989 Amendments to the
SDWA. EPA was to complete the
promulgation of NPDWRs for 83
contaminants, in three phases, by June
-------
Federal .Register / Vol. 56. No. 20 7 Wednesday, January 30. 1591 ./ Rules and Regulations 3531
19. 1989. After 1989, an additional 25
contaminants must be regulated every
three years (section 1412(b]).
B. Regulatory History
In the 1986 Amendments to the
SDWA. Congress required that MCLGs
and MCLs be -proposed and promulgated
simultaneously (section 1412(a)(a)). This
change atreamlinedrdavBlopmentiof
drinking water standards by combining
two steps in the regulation •development
process. Section 1412(a)(2) .renamed
rgQBTnmanriaH maximum contaminant
levels (RMCLs) as maximum
contaminant level goals IMCLGa).
To ensure compliance with the
provision that MCLGs and MCL» he
proposed and promulgated
simultaneously audio ensure adequate
opportunity •for public comment tm -these
proposed standards, EPA proposed as
RMCLs, ptioni for establishing
MOJGsJsee 66 FR 30370. p. 30404).
However, the MCLGs promulgated
today use -the RID option wrth«n
application «f -an e Jditional -uncertainty
f actor up to -10, except as uuleil for
asbestos.
1. How MCLGa Are Developed
MdGs are set at.concentratiBa levels
at which no known -or anticipated
adverse health -effects -would-ocoor.
allowing lor«n*dequate-maismof
safety. •Establishment of a vpecffic
MCLG depends en the'evidence-of
caroinogemdty bom tlrmking water
exposure or the Agency '-s reference -dose
(RID), which is calculated ior •each
specific contaminant
The cancer classification -for a specific
chemical *8fid 'uie reference tluAA are
adopted by two different Agency gixiups.
Decisions -on cancer classifications, are
made by the Cancer Rivk AssBssment
Verification Endeavor (CRAVE) jpoup.
which is composed of representatives of
various EPA program offices. Decisions
on EPA reference doses (nsingimn-
cancer -endpointB only) are mad*
through the Agency Reference Dose
work -group, also -composed of
representatives of vuriuus EPA prugruiu
offices. DedsioOT by CRAVE and the
RfD groups represent policy decisions
forthe Agency and are uaed by the
•feapective regulatory piograms •» the
basis for-regulatory decisions. Dedshms
of these two groups are published in the
Agency's Integrated Hisk Information
System (IRIS). Ibis ays tern -can be
accessed ~by the publicly -contacting
Mike WcLsmgMm of DIALCOM.lnc, «t
aoa-488-6650.
The RfD is an estimate, with an
uncertainty spanning perhaps an order
of magnitude, of a daily exposure to the
-------
3532 FsdorsJ
/ Vol. 56. No. 20 / Wednesday, January 30. 1991 / Rules and Regulations
human population (including sensitive
subgroups) that is likely to be without
an appreciable risk of deleterious health
effects during a lifetime. The RfD is
derived from a no- or lowest-observed-
adverse-effect level (called a NOAEL or
LOAEL. respectively) that has been
identified from a subchronic or chronic
scientific study of humans or animals.
The NOAEL or LOAEL is then divided
by the uncertainty factor to derive the
RfD.
The use of an uncertainty factor is
important in the derivation of the RfD.
EPA has established certain guidelines
(shown below) to determine which
uncertainty factor should be used:
10—Valid experimental results for
appropriate duration. Human exposure.
100—Human data not available.
Extrapolation from valid long-term
animal studies.
1,000—Human data not available.
Extrapolation from animal studies of
less than chronic exposure.
1-10—Additional safety factor for use
of a LOAEL instead of a NOAEL.
Other—Other uncertainty factors are
used according to scientific judgment
when justified.
IT. general, an uncertainty factor is
calculated to consider intra- and
interspecies variations, limited or
incomplete data, use of subchronic
studies, significance of the adverse
effect, and the pharmacokinetic factors.
From the RfD, a drinking water
equivalent level (DWEL) is calculated
by multiplying the RfD by an assumed
adult body weight (generally 70 kg) and
then dividing by an average daily water
consumption of 2 L per day. The DWEL
assumes the total daily exposure to a
substance is from drinking water
exposure. The MCLG is determined by
multiplying the DWEL by the percentage
of the total daily exposure contributed
by drinking water, called the relative
source contribution. Generally, EPA
assumes that the relative source
contribution from drinking water is 20
percent of the total exposure, unless
other exposure data for the chemical are
available. The calculation below
expresses the derivation of the MCLG:
NOAEL or
LOAEL
uncertainly
• factor
mg/kg/
body
weight/
day
(1)
DWEL=
RfD x body
weight
daily water
consumption
in L/uay
= mg/L (2)
MCLG = DWEL x drinking water
contribution (3)
For chemicals suspected as
carcinogens, the assessment for
nonthreshold toxicants consists of the
weight of evidence of carcinogenicity in
humans, using bioassays in animals and
human epidemiological studies as well
as information that provides indirect
evidence (i.e.. mutagenicity and other
short-term test results). The objectives
of the assessment are (1) to determine
the level or strength of evidence that the
substance is e human or animal
carcinogen and (2) to provide an
upperbound estimate of the possible risk
of human exposure to the substance in
drinking water. A summary of EPA's
carcinogen classification scheme is:
Group A—Human carcinogen based
on sufficient evidence from
epidemiological studies.
Group Bl—Probable human
carcinogen based on at least limited
evidence of carcinogenicity to humans.
Group B2—Probable human
carcinogen based on a combination of
sufficient evidence in animals and
inadequate data in humans.
Group C—Possible human carcinogen
based on limited evidence of
carcinogenicity in animals in the
absence of human data.
Group D—Not classifiable based on
lack of data or inadequate evidence of
carcinogenicity from animal data.
Group E—No evidence of
carcinogenicity for humane (no evidence
for carcinogenicity in at least two
adequate animal tests in different
species or in both epidemiological and
animal studies).
Establishing the MCLG for a chemical
is generally accomplished in one of
three ways depending upon its
categorization (Table 14). The starting
point in EPA's analysis is the Agency's
cancer classification (i.e.. A, B, C, D, or
E). Each chemical is analyzed for
evidence of carcinogenicity via
ingestion. In most cases, the Agency
places Group A. Bl, and B2
contaminants into Category I, Group C
into Category II, and Group D and E into
Category III. However, where there is
additional information on cancer risks
from drinking water ingestion (taking
into consideration weight of evidence.
pharmacokinetics and exposure)
additional scrutiny is conducted which
may result in placing the contaminant
into a different category. Asbestos and
cadmium are examples where the
categorization was adjusted based on
the evidence of carcinogenicity via
ingestion. In the case of chromium.
where there is uncertainty in the
ingestion data base, the Agency used
the RfD approach (described below) to
derive an MCLG even though the
chemical has not been categorized. This
issue is discussed below. Where there is
no additional information on cancer
risks from drinking water ingestion to
consider, the Agency's cancer
classification is used to categorize the
chemical. In the cases of styrene and
tetrachloroethylene, where the Agency's
cancer classification is unresolved. EPA
used its categorization approach to
derive an MCLG.
EPA's policy is to set MCLGs for
Category I chemicals at zero. The MCLG
for Category II contaminants is
calculated by using the RfD/DWEL with
an added margin of safety to account for
cancer effects or is based on a cancer
risk range of 10"B to 10~° when non-
cancer data are inadequate for deriving
an RfD. Category III contaminants are
calculated using the RfD/DWEL
approach.
TABLE 14.—EPA's THREE-CATEGORY APPROACH FOR ESTABLISHING MCLGs
Category
1
II...
Ill
Evidence of ccranogcmcsty via ingooEtm
Strong ovrdonco coneidoring weight ofl Otfidonco phormocohinotictx ond
oapoouro.
Urvtitcd ovtdcnoo oonddoring wccght
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Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
3533
The MCLG for Category I
contaminants is set at zero because it is
assumed, in the absence of other data.
that there is no known threshold.
Category I contaminants are those
contaminants which EPA has
determined that there is strong evidence
of carcinogenicity from drinking water
ingestion. If there is no additional
information to consider on potential
cancer risks from drinking water
ingestion. chemicals classified as A or B
carcinogens are placed in Category I.
Category II contaminants include
those contaminants which EPA has
determined that there is limited
evidence of carcinogenicity via drinking
water ingestion considering weight of
evidence, pharmacokinetics, and
exposure. If there is no additional
information to consider on potential
cancer-risks from drinking water
ingestion. chemicals classified by the
Agency as Group C carcinogens are
placed in Category n. For Category II
contaminants two approaches are used
to set the MCLCs—either (I) setting the
goal based upon noncarcinogenic
endpoints (the RfD) then applying an
additional uncertainty (safety) factor of
up to 10 or (2) setting the •goal based
upon a nominal lifetime cancer risk
calculation in the range of 10"* to 10~*
using a conservative calculation model.
The first approach is generally used;
however, the second is used when valid
noncarcinogenicity data are not
available end adequate experimental
data are available to quantify the cancer
risk. EPA is currently evaluating its
approach to establishing MCLGe for
Category II contaminants.
Category III contaminants include
those contaminants for which there is
inadequate evidence of carcinogenicity
via ingestion. If there is no additional
information to consider, contaminants
classified as Group D or E carcinogens
are placed .in Category III. For these
contaminants, the MCLG .is established
using the RfD approach.
2. Response to Comments on EPA's Zero
MCLG Policy
The purpose of MCLGs under the
SDWA is to set goals for both
carcinogens and noncarcinogens, at a
level at which "no known or anticipated
adverse effects on the health of persons
occur and which allow an adequate
margin of safety." SDWA section
1412(b)(4). In its rulemaking on volatile
synthetic organic chemicals (VOCs), the
Agency articulated its policy of setting
MCLGs at zero for known and probable
human carcinogens. See 47 FR 9350
(March 4.1982). 49 FR 24330. at 24343
(June 12.1984) and 50 FR 46880. at 46895
(Nov. 13.1985). Multinational Business
Services. Inc. (MBS) asked the Agency
to reconsider this policy which MBS
considered a departure from the
consistent application of risk
assessment principles by federal
agencies in regulating carcinogens.
Instead. MBS recommended that EPA
establish MCLGs for such contaminants
at calculated negligible risk levels. In
the May, 1989 propcsal of today's rule,
the Agency indicated that it intended to
continue the zero MCLG policy. At the
same time, the Agency agreed to
address the MBS request end any other
comments on the policy.
In the VOCs rulemaking, the Agency
considered three major options (and
several variations) for Betting MCLGs
(then called "recommended maximum
contaminant levels") for the
carcinogenic VOCs. These were: zero
MCLGs, MCLGs set at the analytical
detection limit, and MCLGs set at non-
zero levels based on calculated
negligible contribution to lifetime risks.
(50 FR 46880. at 46884.) The Agency
recognized that humans can tolerate and
detoxify a certain threshold level of
noncarcinogens, and therefore found it
appropriate to set MCLGs for the
noncarcinogenic VOCs above zero.
However, in the Agency's view a
threshold .for the action of potential
carcinogens could not be demonstrated
by current science; it was conservatively
assumed that no threshold exists, absent
evidence to the contrary. Id. Any
exposure to carcinogens might represent
some finite level of risk, the magnitude
of which would depend on dosage and
potency of the particular carcinogen.
Under these circumstances, in the
Agency's judgment, an MCLG above
zero did not meet the statutory
requirement that the goal be eet where
no known or anticipated adverse elfects
occur or allow an adequate margin of
safety.
The Agency believed that MCLGs of
zero for the carcinogens would also best
reflect the Agency's general philosophy
that, as a goal, carcinogens should not
be present in drinking water. Moreover,
the legislative history of the SDWA
specifically authorized this regulatory
option. "The (MCLG) must be set to
prevent the occurrence of any known or
anticipated adverse effect It must
include an adequate margin of safety.
unless there is no safe threshold for a
contaminant. In such a case the (MCLG)
should be set at the zero level." [H.R.
Rep. No. 1185,93d Cong., 2d. Sess. 20
(1974). reprinted in "A Legislative
History of the Safe Drinking Water Act"
1982 at 552.] EPA's decision to
promulgate zero MCLGs for the
carcinogenic VOCs was upheld in the
"VOCs decision." Natural Resources
Defense Council v. Thomas. 624 F.2d
1211 (D.C. Cir., 1387). (EFA's
determination was "well within the
bounds of its authority" under the
SDWA. Id. at 1213).
Comments on the zero MCLG issue in
the May 1989 proposal were received
from eighteen commenters in addition to
MBS. Virtually all of the issues in these
comments have been raised and
addressed earlier. See49 FR 24330 (jane
12,1984) and 50 FR 46895 (Nov. 13.19B5).
MBS and other commenters disagree
with the Agency's interpretation of the
statutory standard lo set MCLGs at a
level to prevent the occurrence of any
known or anticipated adverse health
effects with an adequate margin of
safety. These commenters argue that
Congress intended MCLGs to give
"reasonable." not "absolute." assurance
against adverse health effects. MBS and
others maintain that health effects are
not "anticipated" .absent evidence
indicating they should be expected. We
note that the House Report cited earlier
indicates that "the Administrator must
decide whether any adverse effects can
be reasonably anticipated, even though
not proved to exist" H.R. Rep. No. 1185,
id Some commenters are'critical of the
Agency's "reliance" on the House
Report language addressing the situation
where there is no known safe threshold.
These commenters argue that EPA's
interpretation is "inconsistent" with
other legislative history. MBS, for
example, cites the House Report
discussion of a study to be conducted by
the National Academy of Sciences
(NAS) to support its position that
Congress did not intend MCLGs to be
set at zero. The Committee directed
NAS to develop recommendations of
maximum contaminant levels "solely on
considerations of public health" and not
to be "influenced by political, budgetary,
or other considerations." Id., at 551. In
recommending an adequate margin of
safety, NAS was to consider, among
other factors, the margins of safety used
by other regulatory systems. Id.
However, as the Committee made clear,
determining an adequate margin of
safety was but the final step in the
process of setting an MCLG. The
Administrator must first decide if any
adverse health effects can reasonably
be anticipated, even though not proved
to exist. It was necessary to determine
an adequate margin of safety only if
there is a safe threshold for the
contaminant If there is no safe
threshold, the MCLG "should be set a.
the zero level." Id., at 552. We find
nothing in the discussion of the NAS
study to contradict the Committee s
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3534
Kagioisr / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
explicit recognition of the fact that there
may be circumstances where there is no
safe threshold for a contaminant.
Some commenters maintain that the
Agency's interpretation of the SDWA
should be determined by interpretations
of other statutes that direct egencies to
set "safe" standards. In this regard,
several commenters point to the "vinyl
chloride decision" construing section
112 of the Clean Air Act (CAA). Natural
Resources Defense Council. Inc. v. EPA.
824 F.2d 1146 (D.C. Cir. 1987). Pursuant
to section 112 of the CAA. the
Administrator sets emission standards
"at the level which in his judgment
provides an ample margin of safety to
protect the public health." The court
found that use of the term "safety" is
significant evidence that Congress "did
not intend to require the Administrator
to prohibit all emissions of non-
threshold pollutants." 824 F.2d at 1153.
The court cited the Supreme Court's
"benzene decision" for the proposition
that "safe" does not mean "risk free"
and that something is "unsafe" only
when it threatens humans with "a
significant risk of harm." Industrial
Union Dept, AFL-CIO v. American
Petroleum Inst.. 448 U.S. 607, 640 (1980).
MBS argues that the "vinyl chloride
decision" is particularly compelling
since the term "margin of safety"
appears in both section 112 of the CAA
and section 1412 of the SDWA.
However, the court in the "VOCs
decision" noted that the Supreme
Court's "benzene decision" was based
on "a close reading of the statutory
language of OSHA. which we note
differs significantly from the statutory
scheme that we confront in this case.
The OSHA language that the Supreme
Court interpreted as incorporating a
requirement of a finding of significant
risk directed the Secretary to set
standards 'reasonably necessary and
appropriate to provide safe or healthful
employment'. 824 F.2d at 1215-1216.
Accordingly, there must be a threshold
determination that the place of
employment is "unsafe" in the sense
that significant risks are present and can
be eliminated or lessened by changing
practices. 024 F.2d at 1215. The court in
the "VOCs decision" found that this
"significant risk" standard did not apply
to the Administrator's decisions to
regulate contaminants under the SDWA.
824 F.2d 1C11.1216.
We have followed a similar restraint
in importing interpretations from other
statutes on the basis that they are
"analogous." It remains our view that
reliance on such interpretations as
determinative of Congressional intent in
enacting the SDWA is unwarranted.
Section 112 of the CAA and other
statutes cited by commenters are not
"the same as" section 1412 of the SDWA.
They do not have a two-etep regulatory
process'consisting of separate,
aspirational goals, followed by
achievable, enforceable limits.
Feasibility, coct and other factors may
be relevant to determining appropriate
enforcement levels under the CAA and
other statutes and may influence the
concept of "safety." Such factors are not
appropriate in setting MCLCs. Some
commenters point out that EPA has
determined that standards reflecting a
10"" to 10"° risk level are safe and
protective of public health even for
known or probable carcinogens under
other of its authorities. That is true, but
such determinations are not inconsistent
with our position that MCLGs serve
fundamentally different purposes than
enforceable standards.
MBS and a few ether commenters also
suggest that the Agency's general
assumption of no biological threshold of
effect for carcinogens is not appropriate.
MBS maintains there is "an increasing
body of scientific data" indicating that
substances that elicit carcinogenic
response in laboratory animals "actually
appear to have a threshold of effect for
humans." EPA will continue to solicit
the best scientific views and encourages
the public to provide such evidence to
the Agency for consideration. EPA
intends to set MCLGs based upon the
most current scientific data, and is open
to revising current levels based upon
new data.
Some comments indicate concern that
zero MCLGs are impractical since they
are undetectable and unachievable. It
remains our view that MCLGs are. by
statute, different from enforceable
standards: as goals based solely on
health factors they need not be
measurable, affordable or achievable.
Some conunenters maintain that even as
unenforceable goals. MCLGs have
serious practical implications. They
argue that zero MCLGs cause undue
public alarm and will result in the
misallocation of funds to reduce certain
contaminants. We believe the
distinction between aspirational goals
and standards enforceable under the
SDWA is significant and
understandable. We also believe that
those who adopt MCLGs for purposes
outside the SDWA or use MCLGs as
operational standards rather than
aspirational goals do so knowingly:
those decisions cannot influence the
Agency'o setting of MCLGs. In this
context, come commenters argue that
zero MCLGs will have dire financial
results for Agency clean-up actions. We
cannot agree with such a broad
prediction. EPA has determined that
MCLGs of zero are not relevant and
appropriate requirements for Superfund
cleanups. Contaminant levels of zero are
not consistent with cleanup objectives
of CERCLA. See 55 FR 8666, 8750 (March
3.1990).
Some commenters maintain that zero
MCLGs will necessarily drive MCLs to
increasingly stringent enforceable
standards as technology improves and
that such standards are not justified by
their health benefits. The SDWA
provides that MCLs shall be set as close
as feasible to the MCLGs. taking cost
into account. While it is true that an
MCL for a contaminant with a zero
MCLG has a greater potential to
ultimately be more stringent than an
MCL for a contaminant with an MCLG
above zero, a number of factors arc
considered in determining what
constitutes "best available technology"
on which to base the MCLs. Moreover,
while resources should be directed
toward highest risks, it seems premature
to conclude that the resources that may
be necessary to achieve such standards
would be misdirected.
In the opinion of EPA. Category 1
contaminants meet the "no safe
threshold" test established in the House
Report. EPA does not automatically
place contaminants classified as Group
A or B carcinogens in Category I.
Additional scrutiny occurs to determine
what evidence exists of the chemicals'
carcinogenicity via ingestion
considering pharmacokinetics, exposure,
and weight of evidence. If the additional
evidence indicates ihat the overall
evidence of carcinogenicity via ingestion
is limited or inadequate, then the
chemical will be placed in the
appropriate category and an MCLG is
calculated accordingly. For
contaminants placed in Category II, the
MCLG is based on non-carcinogenic
effects using the RfD approach. An extra
margin of safety of 1- to 10-fold is used
to account for the possible carcinogenic
effects of these Category II
contaminants. If data are inadequate to
establish an RfD. then EPA uses a 10" *
to 10"° cancer risk range to establish the
MCLG.
EPA recognizes that other Federal.
State, and public health agencies have
used a risk-based approach foe
regulating carcinogens. As discussed
above, EPA does use a risk-based
approach as an alternative methodology
for Category II contaminants when non-
cancer health effects data are
inadequate to establish an RfD (i.e..
asbestos). Currently EPA is considering
adopting this risk-based alternative as
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Federal Register / Vol. 58. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3535
the primary approach for Category II
contaminants in future regulations (see
55 FR 30374. July 25.1990).
In addition, when EPA establishes
MCLs, it considers the cancer risk at the
MCL to determine whether they would
be acceptable from a safety standpoint.
A target risk range of 10"* to 10" • is
considered by EPA to be safe and
protective of public health.
EPA agrees that MCLCs at zero do not
provide specific information on potency
and mechanism of action; however, EPA
does consider potency and mechanism
of action on a chemical-specific basis in
determining whether there is strong
(Category I) or limited (Category II)
evidence of carcinogenicity. EPA
recognizes that achieving zero levels of
carcinogens in our water supplies or in
other media is not possible; MCLGs are
health goals. Consequently. EPA
believes that reducing the drinking
water exposure to carcinogens should
lead to an overall reduction in the daily
exposures to a compound.
In conclusion, when current scientific
data do not show a safe threshold, it
remains Agency policy that a zero
MCLC for known or probable human
carcinogens best reflects the statutory
directive to establish a level at which no
known or anticipated adverse effects on
health occurs. At the same time, we are
mindful that significant advances are
being made in scientific knowledge and
technology that allow us to know more
about the process of carcinogenicity and
TABLE 15.—RELATIVE SOURCE CONTRIBUTION
to detect contaminants at increasingly
lower levels. We are continuing to
evaluate these advances to determine
whether it is possible to define levels
that have little or no meaning in terms of
cancer risk. If so. the Agency may
determine that the SDWA directive of
"no adverse effects" could be met by
other than zero MCLGs.
3. Relative Source Contribution
Table 15 summarizes the approach
EPA uses to estimate the relative
contribution from other sources of
exposure, including air and food, for the
purpose of calculating the MCLG for
non-carcinogens. EPA requested
comments on this approach.
Drinking water expoaure between 20
and 80%
Drinking water exposure between 80
and 100%
Drinking water exposure lea than 20%
Adequate data are available..
Adequate data are not available
EPA use* actual data—
.. EPA u»w an 80% drinking water eon- EPA usea a 20% drinking water contri-
thoution. button.
EPA uae* a 20% drinking water contribution.
Five conunenters fully supported
EPA's proposed approach for developing
and using relative source contribution
(RSC) factors. One of these commenters
agreed that volatilization data are
currently inadequate for use in
establishing RSCs. Another commenter
believed sufficient data and modeling
techniques for volatilization have been
published and that human exposure
from volatilization of drinking water
could range from 3 to 10 times that from
ingestion. Another commenter believed
current information indicates that the
vast majority of human exposure to
drinking water contaminants occurs
from ingestion; therefore. EPA should
not consider volatilization in developing
RSC factors. One commenter noted that
the majority of contaminants volatilized
from drinking water would not be
inhaled. One commenter stated that
EPA should refine its models on skin
contact and inhalation using a workshop
format present the models to the
Science Advisory Board, and publish the
models for public comment. Many
divergent comments were received on
the use of a 20 percent floor and BO
percent ceiling (see Comment/Response
Document for details). Several
commenters objected to using a 20
percent floor and 60 percent ceiling for
the RSC when actual data are available.
One commenter asked EPA to clarify
that the 20 percent floor accounts for all
routes of exposure to drinking water
contaminants (i.e., inhalation, dermal
absorption, and ingestion).
EPA Response: EPA has not
completed the modeling effort for
estimating drinking water exposure from
volatilization and dermal absorption.
The draft document "Guidelines for
Incorporation of Inhalation and Dermal
Exposures from Drinking Water in the
Calculation of Health Advisory and
DWEL Values" (U.S. EPA, 1989. draft) is
undergoing internal Agency review.
After completion of Agency review, the
document will be available for Science
Advisory Board and external review. In
the meantime. EPA maintains the
position that exposure to drinking water
contaminants from volatilization and
dermal absorption is generally limited
and adequately accounted for in the
selection of relative source contribution
factors. EPA believes that the 20 percent
floor is very protective and represents a
level below which additional
incremental protection is negligible. In
addition, below 20 percent RSC from
water is a clear indication that control
of other more contaminated media will
have a significantly greater reduction in
exposure. EPA believes the 80 percent
ceiling is required because, even if
nearly all exposure is currently via
drinking water, some portion, albeit
small of the adjusted daily intake (ADI)
should be reserved to protect
populations with unusual exposures and
future changes in the distribution of the
contaminant in the environment EPA
does not rely on the limits when
adequate exposure data exist between
20 and 80 percent but when data are not
adequate, the 20 percent floor and 80
percent ceiling are prudent and
protective of public health.
4. Inorganic MCLGs
a. Asbestos. EPA proposed an MCLG
of 7 million fibers/liter (rounded off
from 7.1 million) for asbestos fibers
exceeding 10 micrometers in length
since sufficient health and occurrence
data exist to justify a national regulation
and the 1986 SDWA Amendments
require the Agency to regulate this
contaminant. EPA's proposal of 7 million
fibers/liter (for fibers greater than 10
micrometers in length) is based upon
evidence of benign polyps occurring in
male rats following the oral
administration of intermediate (>10
micrometer range) size chrysotile fibers.
Public Comments. A total of 19
individuals or organizations provided
comments in response to the MCLG
proposal regarding asbestos. A number
of commenters (13) stated that while
recognizing the health hazards
associated with inhalation exposure, it
was not appropriate to develop an
MCLG for asbestos due to the
inadequacy of data establishing health
risks via ingestion of asbestos. Four
commenters stated that asbestos should
not be considered as having "limited"
evidence of carcinogenicity (Group C),
but instead should be placed in "Group
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353S Fodksaal
/ Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
C" xvith the MCLG based on the No-
Observed Adverse-Effect Level
(NOAEL) or Lowest-Obsemed-Adverse-
Effect Level (LOAELJ for ingested
asbestos. One commenter recommended
developing a heaiui aavisory oasea oo
available data instead of proposing an
MCLC for asbestos. Another commenter
objected to asbestos carcinogenic
classification (limited evidence. Croup
C) in view of the EPA'a classification of
inhaled asbestos as Croup A (known
human carcinogen) and recommended
an MCLG of zero.
EPA Response. EPA recognizes that
the evidence for the health effects of
ingested asbestos has (imitations.
However. EPA beliavee that there is a
sufficient basis to justify regulating
asbestos for the reasons outlined in the
November 13,1985. notice. Furthermore.
the 1988 SDWA amendments direct EPA
to regulate asbestos. The reasons
outlined in the aforementioned
November 13,1983. notice are
summarised below:
0 Asbestos has been shown to be a
human carcinogen through inhalation
exposure and is classified by EPA as
Croup A (human carcinogen).
0 The results of the- National
Toxicology Program {OTT?} bsoassay
showed an asssKaatios betwses the
ingestioss of eobastas Sbsro 3S percent of
which were greetas- than 1 Hsicsometera
in length and beniga gaatrointaatinal
tumors (adenomatous polyps) in male
rats. A parallel NTP study of fibers, S3
percent of which wera 10 micrometer in length)
for asbestos following review of public
comments.
b. Cadmium. In the 1989 proposal (54
FR 22032), EPA reproposed an MCLG of
8.006 tag/1 for cadmium. This value was
baaed upon a DWEL of 0.018 mg/L using
human renal dysiuscticn as en endpoint.
Public Comment. Comments on the
proposal were reeerrod arguing that (a)
the current interim 0.01 mg/1 standard
should be retained or possibly
increased, (b) cadmium in drinking
water should be regulated ao a
carcinogen and thus the MCLG should
be set at zero, or {c} cadmium produces
learning disabilities, birth defects, and
heart disease and thus the MCLG should
be oet at sero.
Those vfh® supported retaining the
current interim 0.02 mg/1 standard or a
higher value based their argument on a
variety of points, including the
following: (a) The interim 0.01 tog/1
standard so safe, and/or fb) the current
0.01 mg/1 otanderd io ouppsrtcd by the
conclusion of 8ho World Health
Organization (WHO) that the
proviBJoaol foalarablG weakly intake for
cadmiuEi ahouluJ bo established at Q
level not to excGod OKMXS m@/p3Kron.
rrato? ofeodld b® rsgialated so a
Group i eessmagsa (La, oet the MCLC &t
zero), eoiiGzrtevaljj. provided EM
extensive analjro&a of ths oaccgenic
routes of expooara in agfeemenJ mth
EPA'o owa
the otasuJoxd ofejyald be SGKB. oo
cadmhsEi ^psdusoa lQaraiJzs§ dioobitefec,
birth defects, aad heart diaeacs. but ths
erse
comment
to condsds th®& the
would
effects should thoy OCCKT.
EPA Rsspaitssa. WMla Q level
mg/1 is pyobabljf witfeaMtf offset ia meat
individoaio. EPA to sot Eoavimsed that a
level of 0.01 mg/1 c? higher contains an
adequate margin of safety to protect
sensitive subpopulations as required by
the SDWA. As noted in the HS39
proposal, WHO recommends 0.005 mg
cadmium/1 of drinking water, a value
identical to the proposed MCLG; the 0.4-
0.5 mg/person value cited in the
comments principally concerns the diet
which, in EPA's opinion, is not relevant
to Q drinking water standard.
Ao stated in the 1988 proposal. EPA
classified cadmium in Gressp Bl,
probable human carcinogen, based upon
animal and human evidence of long
cancer from inhalation exposure.
Chronic oral animal studies with
cadmium have shown kidney dsmage
but no carcinogenic activity and
ingestion-specific human data are not
available. Therefore, in setting an MCLG
for cadmium in drinking water, EPA
believes the lack of cancer dose-
response evidence from inge&tion of
cadmium justifies considering cadmium
as a Category 10 contaminant. Those
comments that conclude that essfaiwsa
is a carcinogen provide no sava avidenca
that cadmium is carcinogenic via
drinking water but rather, argue that it is
prudent to assume that cadmium ia
carcinogenic via ingestion. As drinking
water studies in rats ef two cadmium
salto hew® not shown Q dose-response
basis for risk (®.g.. ATSDK. 5S89J. EPA
believes that for drinking wote?
purposes cadmium choukU bo a Category
HI contaminant (chronic tojociiy but
lacking evidence of camisogenscBty).
The commsntcF arguing that cadmium
produces learning disabih'tiea birth
defects, end heart diseaes provides, no
standard wookJ not protest Qgasast ouch
effects should they occur at feigher levels
of exposures. EPA dissgreso that the
MCLG should be set at zaro on this
After reviewing the public caraments,
EPA has concluded &hat cadmium
should be placed in Category II! and
that an MCLG of 0.005 mg/l for
cadmium, as proposed, baaed on the
most sensitive endpoint is mpgrapriate.
c. Chromium. In the 19@& proposal (54
FR 22032). EPA repropOBad an MCLG of
O.i mg/1 for total chromium (chromium
III and VI).
Public Comment Comments were
received that recommended that (a) the
0.1 mg/1 value be adopted, (b) separate
standards be adopted for Cr VI and Cr
III as there is no evidence that Cr ffi Is
oxidised to Cr V! in drinking water, and
(c) chromium be considered potentially
carcinogenic to humans via the oral
route; thus, EPA should proiaafgate an
MCLG of 2Qi?a for chromium.
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Federal Register / Vol. 56, No. 20 / Wednesday, January 30. 1991 / Rules and Regulations 3537
r.PA Response: The 1989 proposal
stated that "EPA's Office of Research
and Development has shown Cr HI to
oxidize to Cr VI in the presence of an
cxidant such as chlorine at
concentrations similar to those used to
'•iisinffict drinking water." EPA
maintains this view despite some public
. -mmenters who state that then: is no
:v;dence that Cr III is oxidized tc Cr VI.
Those commentcrs who argued that
chromium is carcinogenic, in pert.
support EPA's conclusion that Cr VI is
carcinogenic following exposure by
inhalation. From a hazard identification
perspective. EPA has classified Cr VI in
Croup A. i.e., a human carcinogen via
inhalation, and considers Cr VI to have
various genotoxic characteristics
including being a muiager. and
clastogcn. in comparison, the evidence
ior Cr III is largely non-positive cr
equivocal and is viewed as inadequate
io develop more clear conclusions.
N'ctablv Cr III in trace amounts is an
essential nutrient for the metabolism of
carbohydrates.
Specific dose-response evidence for
Cr VI camnogerucity by oral exposure
is not available at this juncture.
Commenters did not present any new
information on this point. In comparison,
ths body of dose-response evidence for
inhalation exposure is relatively larpe
and consists mainly of human data. The
data base comes from epidemiolc^ic
studies of chromate and ferrochromium
production workers, chrome pigment
workers, and chrome platers where the
predominant chromium species is Cr VI.
While lung cancer is the focus of these
studies, there is also some evidence of
j<.'. tr.cressed hazard of zaatrointestinal
trsct cancer suggesting that respiratory
clearance and swallowing or some other
physiologic distribution of a reactive
chromium species is taking placs.
Unfortunately, most studies did not
investigate or did not detect the
presence of any clear dose-response
relationships, nor is it obvious that other
specific confounding factors for ths
possible gastrointestinal hazards were
accounted for.
While oxidation of Cr III to Cr VI may
occur in the water treatment system.
i eduction of Cr VI to Cr III occurs in
mammalians. The saliva and gastric
juice in ihe upper alimentary tract cf
rr.ammals. including humans, have a
varied capability to reduce Cr VI with
the gastric juice having a notably high
capacity. To the extent that Cr VI
survives these reduction environments
other organs/tissues such as the liver.
red blood ceils and seme lung ceils are
also reducing environments. Thus, the
body's normal physiology provides
detoxification for Cr VI, which provides
protection from the oral toxicitv cf Cr
"I.
EPA'recognizes that by focusing on
total chromium the issues of chromium
«pecies-specific toxicitv. e.g..
carcmogenicity, become mixed. We note
that Cr III and Cr VI chemistry is
already intertwined in the waisr
treatment process since the two valence
states of chromium ere in a dynamic
equilibrium with the degree of oxidation
depending on such factors as pH.
dissolved oxygen, or the presence of
reducing agents. Other equilibriums
exist in the mammalian system and thus
a clear separation of Cr HI and Cr VI is
not feasible at this time.
The lack of available Cr VI dose-
response information for oral exposure
precludes an estimation of the possible
magnitude cf cancer risk, if any, from
drinking water exposure. The available
information shows that the capacity for
reduction of Cr VI to Cr III can be quite
high relative to expected drinking water
levels of total chromium. There is,
however, insufficient information to
describe the rates of reduction and the
temporal fate of free or biologically
available Cr VI. Since Cr VI is
preferentially absorbed compared to Cr
III. the amount of biologically available
Cr VI is uncertain.
EPA concludes that the presence of Cr
VI in drinking water should be
minimized in recognition of its biclogical
reactivity including it* potential for a
carcinogenic hazard. Such minimization
will limit the likelihood of saturating the
normal reduction/detoxification
mechanisms in humans and likawise
limit the systemic absorption of any
residual Cr VI. Without the necessary
information to further evaluate the
possibility of carcinogenic risk, EPA
believes that drinking water exposure
limitations for total chromium based
upon other, i.e., non-carcinogenic, health
endpoints is the only feasible epproech
to follow at this time.
The MCLG for total chromium is
developed from health effects data for
Cr VI, the more toxic chromium species.
and is based on EPA's RfD methodology
(see 1989 proposal). Since the MCLG
includes both Cr in and Cr VI, no
category has been assigned for total
chromium due to some of the issues
discussed earlier. Should new
information become available which
rdeq-jotely demonstrates the cancer risk
from ingestion of Cr VI. the MCLG for
total chromium would be reexamined.
especially since Cr VI levels can
predominate from spills, uncontrolled
waste sites, or geologic formations of Cr
VI makeup. Therefore. EPA is
promulgating an MCLG of 0.1 mg/1 (100
ug/1), as proposed in 1989. end further
recommends that the n uncertainty
regarding Cr VI carcinogenic risk
warrants additional investigation.
The MCLG level also falls into the
estimated safe end ^ adequate daily
dietary intake range of 50 to 2CO jig/day
for Cr III established by the Mational
Research Council in the National
Academy of Sciences (i\'AS, 1039). T.:e
lower limit is based on the absence of
deficiency symptoms in individuals
consuming an average cf 50 ua/day
chromium. The uppar limit was
identified from several studies where no
adverse effects were noted in
individuals consuming 200 u-g/day
chromium. Consequently, for the
reasons stated above. EPA promulgates
an MCLG of O.I mg/1, as proposed.
d. Mercury. EPA proposed an MCLG
of 0.002 mg/1 for msrcury in the May 2.?,
1989 prooosal. The MCLG was derived
from a DWEL cf 0.01 rr.g/1 applying a CJ
percent contribution from drinking
water. The EPA held a workshop on
issues regarding the DWEL for merci^y
(EPA, Peer Review Workshop on
Mercury Issues, Summary Report,
October 23-27.1387). The workshop
considered three major studies (Oruet et
al.. 1978: Andres P.. 1384; Bemaudin et
al.. 1981) using the same
endpoints(kidney damage) for mercury
toxicity. The workshop concluded that
0.01 mg/1 was an cppropriate level for
the DWEL.
Public Comments: EPA addressed the
public comments received in response to
the previous proposal of November 13,
1985 in the Federal Register Notice of
May 22.1989. In response to the Federal
Register Notice of 1989, one commenter
questioned the use of ths studies by ETA
for the calculation of DWEL nnd
recommended the use cf the Fitzhagh c-t
al. (1950) study instead. The Fitzhugh
study noted damage to the kidneys as
did the studies selected by ET'A. Tho
NOAEL frcm the Fitzhugh study was
0.315 mg/kg as compared ;o the LOAEL
of 0.32 mg/kg from which EFA ck-rived
theJJWEL
EPA Response: EPA examined the
Fitzhugh study and found it
inappropriate for DWEL determination
because of the lack of reporting on
which adverse health effects were
observed in each dosing group.
Consequently, EPA will continue to base
its MCLG on the three studies
previously cited. Thus, EPA has placed
mercury in Category III and promulgates
an MCLG of C.002 ir.jj/1 in drinking
water.
e. Nitrate/Nitrite. In the 1989 proposal
(54 FR 22062). EPA proposed MCLGs of
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3538 Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
10 mg/1 (as N) for nitrate and 1 mg/1 (as
N) for nitrite, and, in addition, proposed
that the sum of nitrate and nitrite shall
not exceed 10 mg/1 (as N). EPA based
the MCLGa on tne toxicity cf nitrate in
humans due to the reduction of nitrate to
nitrite in the human body. By reacting
with hemoglobin, nitrite forms
nethcrr.oglobin (n;et lib], which will not
transport oxygen to the tissues and thus
can lead to asphyxia (i.e.. blue babies)
which, if sufficiently severe, can lead to
death. The current standard for nitrate,
which was promulgated in 1975, was
based on the previous Public Health
Siandard v.-hich. in iurn, was based en a
litarature survey (Walton. G. 1951.
"Survey of Literature Relating to Infant
Methemoglobinemia Due to Nitrate
Contaminated Water." Am. /. Pub.
Health 41:986-996].
The proposed standard is somewhat
more stringent than the current MCL of
ID rr.2/1 because it includes an MCL fcr
nitrite (the more tcxic ferry;I ar.d a joint
standard of 10 mg/i for nitrate and
r.itrita. Since both nitrate and nitrite
result in met Hb, toxicity of nitrate and
nitrits may be additive. EPA proposed
tr.3 joint nitrate/nitrite standard in order
to account for ths possible additive
tc.xicity of these two chemicals and also
to protect against the deterioration of
drinking water quality, since the
presence of nitrite in water is indicative
of water contaminated with sewage.
In the proposal. EPA specifically
requested comments on the following
issues: (1) The potential cancer risk
through drinking water exposure, (2)
potential developmental effects and
whether the proposed MCLC provides
adequate protection against such effects.
and (3) whether a lower MCLC would
us more appropriate.
(1) Nitrate and Cancer
One commenter stated that there is no
definitive evidence from animal
bioassay studies that nitrate itself
causes excess tumors and. further, the
various epidemiological studies that link
nitrate and/or nitrite to cancer are not
conclusive. Another commenter argued
that (a) the Giili et al. (1984)
epidemiology study [Gilli et al..
Concentrations of Nitrates in Drinking
Watsr and Incidence of Gastric
Carcinomas: First Descriptive Study of
the Pierr.onte Region, Italy, Science of
the Total Env., V. 34. pp. 35-48. 1984]
provides evidence that nitrate in
drinking water is oncogenic (i.e..
increased incidence of gastric
carcinomas) and (b) Forman et al. (1985)
and Al-Dabbagh et al. (1986) are
inadequate to conclude whether nitrate
and nitrite are carcinogenic. (Both
Forman el al. (1985) and Al-Dabbagh et
al. (1986) were discussed in the 1989
proposal (54 FR 22062).) Another
commenter noted that the 1989 proposal
referenced a number of epidemiologic
studies (e.g., Burch ei al.. 1987) that
show an association between cancer
and nitrate. Finally, another commenter
stated that several epidemiologic studies
show an association between preformed
"•.'-nitroso compounds qna cancer.
EPA Response. EPA has reviewed the
ddta submitted by tne public as well as
sianificcnt oih'jr daia (sue Drinking
Water Criteria Documen: for Nitrate and
Nitrite, 19901. A! this time. EPA is not
convinced that nitrate and/or nitrite in
drinking watnr presents a potential risk
of cancer. EPA doss not believe that
data concerning the possible
oncogenicity c! ni'rate and/or nitrite
ccn be entirely c.smissea. however.
In attempuna to resolve this issue, it is
desirable to liirec'.iv seek the assistance
of other recierai aeonr.ies concerned
with other sources of nitrate. Thus. EPA
intends to torm an ir.ier-agerjcy work
group to determir.c what, if any,
oncogenic risks exist.
[2] Other Effects
Prior to the Mav 1989 proposal, the
Agency reviewed the possible health
effects associated with nitrate and
nitrite. EPA concluded that (a) infants
are the most sensitive subpopulation. (b)
methemoglobinemia is the most
sensitive toxic endpoint in infants, and,
(c) a level of 10 mg of nitrate and,
separately, a level of 1 mg of nitrite
(both as N) will protect infants
(Note: the calculated RfD is based en this
conclusion).
Since the 1989 proposal, the Agency
has reexamined the RfD for nitrate
considering new data. This review
reaffirmed the original conclusion that
10 mg nitrate per liter would protect
infants.
In reaching this conclusion the
Agency examined a large number of
papers concerning the toxicity of nitrate
and nitrite. These papers separately
dealt with chronic toxicity.
developmental and reproductive
toxicity, and methemoglobinemia
(among other endpoints). Data
concerning both humans and
experimental animals were reviewed.
E?A has reviewed the daia on
developmental and reproductive
toxicity. Based on that review, EPA
believes the data are inadequate to
conclude that nitrate and nitrite present
a risk of developmental or reproductive
effects at the MCLGs.
In addition, the Agency reviewed all
public comments as well. The issues
raised by the public are substantially
similar to those examined by EPA.
Based on a review of the data. EPA
has concluded that an MCLG of 10 and 1
mg/1, respectively, are adequate to
protect infants, and all other groups.
against the nononcogenic effects
presented by nitrate and nitrite in
drinking water.
(3) Other Issues
Other ccrr.menters recommended that
EPA (a) adopt the MCLGs proposed in
1S39 for nitrate and nitrite but not adopt
the proposed MCLG for the sum of
nitrate and nitrite, as it is unnecessary:
(b) adopt the MCLGs proposed in 1989
for nitrate and the sum cf nitrate and
nitrite but not adopt the MCLG proposed
for nitrite, as it is unnecessary: (c) only
adopt the MCLG proposed for nitrate, as
the other two MCLGs ars unnecessary:
and (d) adopt the proposed MCLGs for
nitrate and nitrite but increase the
proposed MCLG for the sum of nitrate
and nitrite frorr. 10 mg/'! to 11 mg/1 (both
asN).
EPA disagrees with recommendations
(a) through (d). above, fcr the following
reasons:
• It is clear that nitrite may occur in
drinking water and also that nitrite is
toxic, thus a nitrite standard is needed.
• As nitrate is toxic because it is
metabolized in the human body to
nitrite, it is reasonable to conclude that
the toxicity of nitrate and nitrite is
additive. Thus, in agreement with the
recommendations of the SAB, a
combined standard for nitrite and
nitrate is warranted.
• Adoption of an 11 mg/1 (as N)
combined standard for the sum of
nitrate and nitrite, in effect, would mean
that a combined standard was
unnecessary. For the reasons previously
stated, EPA disagrees.
Based on the previous discussion.
EPA has placed nitrate and nitrite in
Category III and promulgates the
MCLGs for nitrate, nitrite, arid the sum
of nitrate and nitrite at 10 mg/1.1 mg/1,
and 10 mg/1 (as N), respectively.
f. Selenium. Ir. the 1989 reproposal (54
FR 22062). EPA proposed an MCLG of
0.05 mg/1 for selenium and specifically
reciuested comment as to whether an
MCLG of 0.02 or 0.1 mg/1 might not be
more appropriate. The basis of the
current proposal is discussed below.
Public Comment. EPA previously
addressed the public comments received
in response to the previous proposal of
November 13.1985 in the Federal
Register Notice of May 22,1989.
(A) The majority of commenters
supported an MCLG of 0.1 mg/1. With
one exception, no significant additional
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Federal Register / Vol. 50. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
3539
:?.ta were provided. However, one
j.:.T.njcnter recommended that based on
2 : j89 study by Yang et al. [Yang ct al..
Gt'jdiss oi Ssfe Maximal Daily Dietary
Sp-'ntake in a oeleni.vcroua Area in
rin.na. j. Traca Ebm. E'sctrolytcs Hadth
C:3.. pan ill. Vol. S. pp. 123-130.1932).
EPA sftouid consider c lower MCLG
v~:ue. In c:'.d:tion. ths seme conxcer.ter
vbscr.'sa that a number of individual*
irks siJcr.iara supplements (i.e.,
::-lenium is an essential trace element)
r.r.d thus exposure may be significantly
greater '.hen EPA anticipates.
ZPA response. The 0.05 mg/1 value
proposed in 1989 is based on a human
effect level observed by the same auinor
(fang e! al.. 1382). EPA normally prefers
to base MCLGs on no-effect levels.
which are more conservative than
human effect levab. Ho\vever, at tie
timn of the 1039 proposal, an
epprocriate no-effect level was not
available. However, Yang et al. (1939)
provides a no-effect level obtained torn
'i human study in China and suggests
that 0.400 rng of selenium/person/day is
a rr.?.x jnel daily safe intake of selenium.
Assuming the consumption of 2 liters
of water/aduit/day. consumption of
water containing selenium at the
proposed C.05 mg/1 MCLG would result
in the inge3Lion of 0.1 mg selenium/
person/day. As previously stated (54 FR
22062), the average daily dietary intake
in this country is 0.125 nig selenium /
person/day. Thus, the combined
ingestion of -.vster containing 0.05 mg/1
and a typical U.S. diet would result in a
total daily exposure of 0.225 mg
sslenium/psrson, a value well below the
0.400 mg selenium that Yang et al.
suggests is safe. Consequently. EPA has
concluded that Yang et al. (1989)
supports the proposed MCLG of 0.05
rns/1.
uPA believes thet the difference (i.e.,
0.175 in? "leniarc/'person/dcy) between
u:atary intake (0.225 mg selenium/
parson/day) and the maximal daily safe
intake cf selenium (0.4 mg selenium/
person/day) recommended by Yang et
al. (1909) i3 adequate to protect thoss
who may take selenium supplements.
Thus, EPA believes that the 0.05 mg/l
value is adequate to protect both the
general public and those who may teke
ssie.iiam supplements.
(B) Although providing no new date,
cthsr ccmmemers raccnuner.ded an
:.!CLG cf 0.1 ng/1 or higher.
£PA Response. EPA disagrees with
these comments for the following
reasons: (1) It is likely that there are
•ndiv.'duals who. whether due to diet or
.applements. consume significantly
more selenium than the 0.125 mg
selenium/'person/day that EPA has
estimated that the average citizen
consumes, and (2) EPA believes that an
MCLG higher than 0.05 nsg/1 may not
rdequately protect those who
chrcnicclly consume such elevated
eraounts of eclenium. Thus. EPA has
rejected these comments that argue for
an iviCLG of C.I ni3/l or more.
After reviewing the public conur.er.ts,
£?A has concluded thst selenium should
be placed in Category III and en MCLG
cf 0.05 rsr/1 is pro^ulca'ed.
S. Volatile Orriaruc Contaminants
(VOC::) MCLGs
a. cis-13-DichIoroethyisne and trans-
1.2-Dichloroethvlene. EPA proposed an
MCLG of C.C7 mg/1 based on a 3-month
studv in rats using cis-1.2-
dichloroeihylene. From that study, a
DWEL of 0.4 mg/1 (rounded from 0.35
ma/i) was calculated and a £0 percent
drinking water contribution was
assumed. For trans-1.2-dichloroethy!er.e.
EPA proposed an MCLG of 0.1 mg/'l
basad on compound-specific data. A
DV/EL cf 0.6 mg/1 was derived and a
drinking water contribution of 20
percent was assumed to determine the
MCLG.
Public Comments and EPA Response.
EPA previously addressed the public
comments received in response to the
earlier proposal of November 13.1985 in
the Federal Register Notice of May 22.
1989. With respect to the cis isomer, one
cocnnenter stated that data on 1.1-
ciichlcroethylene should not be used for
the cis compound, because there is no
evidence that the effects of the two
compounds are similar. Another
commenter stated that the MCLG for
cis-1.2-dichloroetbylene should be based
on Freundt and Macholz (Toxicology
10:131-139.1978). Another commenter
stated that the NTP two-year bioassay
for 1.1-dichloroethylene was a better
study for ceriving a NOAEL/LCAEL for
cztcrminm; MCLGs/MCLs.
For the usns isoaicr, one commenter
stated that il:eir MCL was lower than
EFA's MCL. However, they need to
review the Bemes et al. (Drug Chem.
Toxicol. 8:373-392. ISaO) manuscript
prior to revising their MCL.
Another coznmenter disagreed with
the selection of NOAEL/LOAEL from
ths Barnes et al. study and stated that,
based on the increase in glucose levels
end decrease in aniline hydroxylaae
activity. 17 n-.g/kg/day should be a
LCAEL end not a NOAEL.
The final MCLG for cis-1,2-
dichioroethylene is based en a 3-month
compound-specific study by McCauley
et el. The Agency's RfD Workgroup has
reviewed the data and verified a RfD of
C.01 ing/kg/day.
There are several reasons that the
Agency is not using the Freundt and
Macholz (1978) study to set an MCLG.
First, it is a single eight-hour exposure.
EPA does not generally use single
exposure studies to set lifetime
numbers. Succr-d. it is an inhalation
exnosure and the Agency prefers to use
routs-rceciiic feral) duta if possible.
Third, ths selection of an adverse effect
:.r. ths Freundt and Machclz (1973; study
is questionable. A decrease in
.T.icrc^sn-.al metabolism (i.e.. eniiine
hydroxylase), while an obvious eject, is
f:o: n",r;essarily an adverse effect. Li
fact, if a chemical is activated to a toxic
metabolite, inhibition of that chemical's
metabolism might be beneficial. Fourth.
and most important, the Agency
presently has an oral three-month study
en nis-1.2-dichloroethylene.
The Agency did no I select the NTP
two-year bioassay because they gave
the 1.1-diculoroethylenc in corn cil and
oil vehicles have been reported to
potentiate the adverse effects of 1,1-
dickloroelhyiene (Ciueco et al.. Tcxiccl.
Appi. Pharmacoi. 57:146-155.1331).
Since the new trans-1.2-
dichloroethylene data ore going to be
reviewed by the comrnenter, no Agency
reply is necesaary at this time. With
respect to selection of a NOAEL/LOAEL
in the Barnes et al. (1935) study, the RfD
workgroup did review the data very
carefully. Tables 11 and 12 of the Barnes
et al. (1985) paper do report that there
are significant increases in serum
glucose levels in both male and female
CD-I mice. However, even though the
difference between the low- and high-
dose levels administered to the mice is
•20 fold, there are no differences in serum
glucose levels at these two doses. This
calls into question the toxicological
significance cf the increased glucose
levels. In addition, ths Agency does not
Liow the normal range for variation in
serum glucose fcr this strain. The
Agency's RfD workgroup did not believe
that either ths increased aerum glucose
levels or the decreased aniline
hydroxylase levels (also eee discussion
for cis-1.2-dichlorcethylene) were
adverse effects. Accordingly, the 17 irg/
kg/day tieatment level was used as a
NOAEL EPA has placed cis-1,2-
dichlcroethylene and rrans-1.2-
dichloroethylene in Category III and the
respective MCLGs of 0.07 and 0.1 nsg/1
will be retained.
b. 1.2-Dichlcropropzne. EPA proposed
an MCLC of zero f jr 1.2-
dichlcropropane based on the
statistically significant increased
incidence of hepatoccllular neoplasms
and primary adenomas in male and
fsraaie E8C3F i mice. The frequency of
liver carcinomas alone wcs not
significant for males or females, but
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KsgistBf / Vol. 56, No. 20 / Wednesday. January 30, 1991 / Rules and Regulations
there was an increase in tumors in both
sexes. Also, there was a dose-related
trend in mammary adenocarcir.omas in
female F344 rats. The increased
edenocarcinoma incidence in the female
rats was considered to be significant
since tiie F344 rat has a reianvely low
background occurrence ra;e for these
t;:mo;-s. Therefore, EPA classified 1.2-
r.ichloropropane ir. Group i>2.
Public Comments. Three individuals
or organizations provided comments in
response lo the MCLG proposal
regarding 1,2-dichloropropane. One
corr.menter was in agreement with
EPA's proposed classification of 1.2-
cichloropropane into Group B2, and
with EPA's proposed establishment of
en MCLG at zero. Two commenters
stated that a problem might exist with
the NTP study of B6C3F i mice in terms
of showing a high incidence of tumors in
the control mice compared to the mice
which received the high dose of this
chemical. They suggest a revaluation of
this study before establishinc an MCLG.
EPA Response. The EPA's"
classification of 1.2-dichloropropane in
Group B2 was based on the results of
the final NTP report. This report was
peer reviewed and audited by the Peer
Review Panel and Audit Workgroup.
respectively, and was found acceptable
in terms of results reported in the final
NTP report. EPA concludes that a
reevaluation of this study would not
change the findings of this report.
Consequently. EPA has placed 1,2-
dichloropropane in Category I and an
MCLG of zero is promulgated.
c. Ethylbenzene. EPA proposed an
MCLG of 0.7 mg/1 for ethylbenzene. The
MCLG was derived from a DWEL of 3.4
mg/1, by applying a 20 percent drinking
water contribution and rounding off to
one significant number.
Public Comments. EPA previously
addressed the public comments received
in response to the earlier proposal of
November 13,1985 in the Federal
Register Notice of May 22,1989. In
response to the 1989 Federal Register
Notice, one commenter agreed with the
cnoice of study, NOAEL. and LOAEL,
but questioned the use of a 10-fold
uncertainty factor to convert from
subchronic to chronic exposure. The
commenter explained this position in the
following manner: Since the adverse
effects of doses 3- or 5-fold higher man
the NOAEL were minor and a 2-year
NTP study on mixed xylenes. which
contained 17 percent cthytbenzene
(equivalent to 85 mg of ethylbenzene/
kg/day), showed no adverse effects, the
extra 10-fold uncertainty factor could be
omitted.
EFA Response. EPA believes that the
10-fold uncertainty factor for converting
a subchronic to a chronic study is still
necessary for several reasons. In the
Wolf et al. study (Arch. Ind. H!th 14:387-
398. 1958). the NOAEL of 136 mg/kg WES
adjusted by 5/7 since the animals were
treated for only 5 days/week. Some
recovery from the effects of
ethylbenzene could have occurred
durinn the two days of r.or.-treatment.
The administration of 65 rng of elhyi-
benzene/kg/day as part of an essay of
mixed xylenes does r.ot necessarily
mean that a BS mg ethylbenzene/'kn/day
dose is without eifect since EPA does
not know about potential interactions
among the compounds. In addition, the
finding of miner adverse effects at doses
3- and 5-fold higher than the NOAEL
does not exclude the possibility that
extended exposure at lower doses
would lead to adverse effects. Since
there are many unanswered questions
on the toxicity of ethylbenzene. EPA
feels that the 1.000-fold uncertainty
factor, including a 10-fold for subchronic
to chronic exposure, is appropriate for
this chemical. Consequently. EPA places
ethylbenzene in Category III and the
MCLG of 0.7 mg/1 is promulgated as
proposed.
d. Monochlorobenzene. EPA proposed
an MCLG of 0.1 mg/1 for
monochlorobenzene in the May 22.1989
proposal. The MCLG was derived from a
DWEL of 0.7 mg/1, applying a 20 percent
contribution from drinking water and,
because of reclassification of
monochlorobenzene in Group D
(inadequate evidence for
carcinogenicity) according to the EPA
guidelines, no additional uncertainty
factor for possible carcinogenicity. This
MCLG is a revision of the MCLG of 0.06
mg/1 (derived from a DWEL of 3.0 mg/1,
applying a 20 percent contribution factor
from drinking water and an uncertainty
factor of 10 used with agents classified
in Group C (possible human carcinogen:
for monochlorobenzene, limited
evidence in animals based on increased
neoplastic nodules in liver of male rats
in one bioassay)) previously proposed in
November 13.1985. Revision of the
MCLG to change the basis for the DWEL
and downgrade the carcinogenicity
classification from Group C to Group D
(Category II to III) is the result of further
review of data and review of the MCLG
for monochlorobenzene by the EPA's
Science Advisory Board in 1986.
Public Comments. EPA addressed the
public comments received in response to
the previous proposal of November 13,
1985 in the Federal Register Notice of
May 22,1989. Two ccmmenters
responded to that Federal Register
notice. The first commenter supported
reclassification of monochlorobenzene
from Group C to Group D. The second
commenter felt that the appropriate
classification is Group C and that an
additional uncertainty factor should be
applied to the study used to dnrive the
DWEL to account for limitations in
study design.
EPA Response. EPA agrees with the
ccmmanter who supports
reclcssification of rr.oncchloroDenzene
from Group C to Group 0. EPA
reclassified monochloroDenzene after
concluding that the comoinaticn o:
neoplastic nodules and hepatcceiiular
carcinomas in male rats in the
carcinogenicity bioassay was not
adeouate evidence of a treatment-
related effect to, in turn, support limited
evidence for csrcinogenicity of
monochlorobenzene in animals. EFA
disagrees with the second commenter
that an extra uncertainty factor is
needed with the study used as the basis
for the DWEL because EPA considers
the 1.000-fold uncertainty factor already
used with the study as adequate
compensation for uncertainty
surrounding limitations in the study
design. Consequently, as discussed
above. EPA places monochlorcbenzene
in Category III and an MCLG of 0.1 mg/1
is promulgated.
e. ortho-Dichlorobenzene. EPA
proposed an MCLG of 0.6 mg/1 for
ortho-dichlorobenzene in the May 22,
1989 proposal. The MCLG was derived
from a DWEL of 3.0 mg/1, applying a 20
percent contribution from drinking
water.
Public Comment. One commenter felt
that because a NOAEL from a chronic
(two-year) study in rats was used for
calculation of the DWEL. the
uncertainty factor should be 100 instead
of 1.000 as used by EPA.
EPA Response. EPA disagrees with
the comment that the uncertainty factor
for the DWEL calculation should be 100
instead of 1.000. Although EPA
ccmmonly applies a 100-foid uncertainty
factor with a chronic (lifetime) study in
rats, EPA chose to use a 1,000-fold
uncertainty factor for tha DWEL
calculation for ortho-dichlorobenzena
because toxicity endpoints were
assessed in a preliminary subchrcnic
(13-week) study in rats thai were not
evaluated in the chronic study and
beceuse of data gaps (an inadequate
reproductive toxicity study in a non-
rodent species reproduction study).
Consequently, EPA places ortho-
cichlorobenzene in Category III and an
MCLG of 0.6 mg/1 is promulgated as
proposed.
/ Styrene. EPA proposed two MCLGs
in the May 22,1989 proposal because
EPA had not yet finalized its
carcinogenicity classification for
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Federal Register / Vol. 56. No. 20 / Wednesday, January 30. 1991 / Rules and Regulations 3541
siyrene. One MCLG of 0.1 mg/'l was
derived from a DWEL of 7 nig/1.
orplying a 20 percent contribution from
drinking water and an additional 10-fold
uncertainty factor by considering the
classification of styrene to be Group C.
The other MCLG was zero, considering
the classification cf styrene to be Group
B2. At meetings on styrene with EPA's
Science Advisory Board in 1S88 and
1990. EPA favored a classification cf
Group B2. whereas the SAB opinion
favored a classification of Group C.
Additionally, at the 1990 meeting with
the SAB. the SAB preferred a
multigeneration reproduction/chronic
toxicity study in rats over the
Eubchronic toxicity study in dogs the
EPA had used for calculation cf the
DWEL.
Public Comments. EPA addressed the
public comments received in response to
the previous proposal of November 13.
1935 in the Federal Register Notice of
May 22,1989. Ln response to that Federal
Register Notice, six commenters
advocated no classification for styrene
or, if it is to be classified, classification
into Group D. One of these commenters
also preferred use of the rat study over
the dog study, as described above, for
calculation of the MCLG. This
commenter felt the MCLG should
therefore be 1.6 rng/1 (which EPA would
round to 2 mg/1). calculated as a Group
D classification, thereby omitting the
extra uncertainty factor of 10 required
for styrene in Group C. Two commenters
supported classification of styrene in
Group B2 and promulgation of an MCLG
of zero, in the opinion that the data are
sufficient to meet the criteria for Group
B2. Two commenters felt the proper
classification for styrene is Group C and
en appropriate MCLG is 0.1 mg/1.
EPA Response. The EPA has not
classified styrene as to its
carcinogeoicity potential at this time.
The EPA has presented to the Science
Advisory Board arguments to classify
styrene in Group B2: probable human
carcinogen. The Science Advisory Board
responsed that the weight of evidence
supported a group C classification. Thus.
the cancer classification issue is still
under review by the Agency.
Via com oil gavage. there is some
evidence that styrene may induce
tumors in rodents, and a cancer risk of 9
x 10"7 per pg/1 is estimated from the
NCI mouse study (NCI. 1979). Available
oral studies in rats have not shown
carcinogenic activity. In setting an
MCLG for styrene in drinking water,
EPA has carefully considered the overall
weight of evidence of cancer, especially:
(1) The comparatively low estimated
cancer potency (based on the com oil
gavage study): (2) the lack of a
carcinogenic response in an adequately
conducted drinking water study. In
addition, styrene is not likely to be
widespread in drinking water based on
occurrence information currently
available in the Agency. Consequently,
EPA is placing styrene in Category II
and is promulgating an MCLG of 0.1 mg/
1 based on the Quasi et al. (1978) study
in dogs.
g. Tetrachloroethylcne. In the May,
1989 notice, EPA proposed an MCLC for
tetrachloroethylene (perchloroethylene
or PCE) of zero. The Agency has found
strong evidence of carcinogenicity from
ingestion based on consideration of the
weight of evidence, pharmacokinetics
and exposure.
The Agency uses a three category
approach to set MCLGs under the Safe
Drinking Water Act (see 50 FR 46944-
46949 (November 13.1985) and 54 FR
22068 (May 22,1989)). A chemical for
•which there is strong evidence of
carcinogenicity is placed in Category I.
As a matter of policy, EPA sets MCLGs
for chemicals in Category I at zero (see
earlier discussion of this policy).
Recognizing the continuing scientific
controversy over the appropriate weight
of evidence for the chemical, the Agency
also solicited public comment on an
MCLG of 0.01 mg/1 which would reflect
a possible human carcinogen (Category
II). EPA received a number of comments
on the proposal and these comments are
addressed below.
In separate actions, the Agency is
currently deliberating concerning an
Agency-wide classification of PCE,
according to its normal procedure. On
December (28). 1990. EPA issued a
notice for publication in the Federal
Register that described the process the
Agency is following to bring these
deliberations to a conclusion. (A Federal
Register citation for that notice was not
available on the date of signature of
today's notice; however, the title of the
notice is "Amendment to Preambles
Published at 54 FR 33418 (August 14.
1989) and 54 FR 50968 (December 11.
1989))".
While these deliberations continue.
EPA must take final action on an MCLG
and NPDWR for tetrachloroethylene.
This chemical is included on the list of
83 chemicals that Congress specifically
directed EPA to regulate. The Agency is
under court order to promulgate
regulations for this contaminant by
December 31.1990. Accordingly. EPA
today is promulgating an MCLG for PCE
in accordance with the three-category
approach developed to implement the
SDWA. This action does not reflect a
final Agency decision on PCE's
classification: it represents a separate
and distinct regulatory evaluation and
risk management decision concerning
FCE. When the Agency completes its
deliberations regarding classification.
we may reconsider the MCLG for
tetrachloroethylene. as appropriate.
Based on EPA's careful review of the
comments received in response to the
May, 1989 notice and the Agency's
evaluation of scientific evidence
available sines the proposal, it remains
EPA's view that there is strong evidence
of carcinogenicity through ingestion and
that PCE is a Category I chemical for
purposes of establishing an MCLG under
the SWDA.
Public Comments. The pivotal
comments dealt with EPA's
categorization of tetrachloroethylene as
a probable or possible human
carcinogen for purposes of setting an
MCLG under the SDWA. One
commenter argued that: (1)
Tetrachloroethylene metabolites/
trichloroacetic acid, which are
carcinogenic, were tested in a sensitive
strain of mice having a high background
liver tumor incidence, (2) mononuclear
cell leukemia observed in animals may
not be relevant to man. and (3) renal
tumors observed in male F-344 rats are
species-specific. One commenter argued
that this contaminant is a probable
human carcinogen; another supported
classification of PCE as a possible
human carcinogen.
EPA Response. Based on the available
carcinogenicity evidence from
experimental animal studies and the
high frequency of occurrence in drinking
water. EPA continues to view PCE as a
Category I contaminant for drinking
water regulation. The evidence for
carcinogenic hazard has two parts, i.e.,
epidemiologic data and animal data as
supplemented by metabolism
information and results from short-term
studies. In 1985 EPA viewed the
epidemiologic data as inadequate to
refute or demonstrate a human health
hazard potential. EPA is aware of two
more recent studies which discuss
increased cancer mortality among dry
cleaner workers. These studies have not
yet been comprehensively integrated
into the epidemiologic assessment for
PCE. It is not apparent however, that
the influence of PCE alone can be
delineated since multiple solvents are
involved in one study and in the other
study in which PCE is the primary
solvent while the findings are
nonpositive. the exposed group was too
small to be useful in risk assessment In
experimental animals, three types of
tumors in rodents contribute to the
inference for a cancer causing potential
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3542 Fadaral Rsgistor / Vol. 56, No. 20 / \Vednesday. January 30. 1991 / Rules and Regulations
in humans. Indications of cancer activity
were seen in mice and rats, in both
sexes, by irJiaiation and oral exposure.
Short-term studies and other
informaticn about PCE metabolism and
toxicity of the metabolites both
contribute to the hazard concern as well
as provide some basis for hypothesizing
about tumor formation and relevancy for
hiirnan hazard assessment
While there is some uncertainty about
the relevance to humans of th-2 animal
tumor endpcints. the totality cf the
animal evidence is judged by EPA to bs
sufficient to viev.' PCE as a Category I
contaminant The lack of key
information does not support the use of
the uncertainties to discount the
sufficient lexrel of animal evidence.
F.PA's response to a number of issues
raised in the public comments are
summcjized below.
(1) Mouse Liver Ti^nor. The
controversy surrounding the liver tumor
response in the B6C3F1 male mouse is
well recognized, end EPA is aware of
the divergent scientiSc viewa regarding
the use of this animal endpoint in
carcinogen risk assessment. The Agency
undertook extensive review of this issue
while it was developing the carcinogen
risk assessment guidelines and in 1987
solicited PCE-related advice from thd
SAB. The Agency's position is that
mouse liver tumors are considered
evidence for potential human
carcinogenicity. The guidelines take the
position that the mouse liver rumor
response, when other conditions for
classification of "sufficient" evidence in
the animals are met (e.g., replicate
studies of malignancy, tumors at
multiple sites, etc.) should be considered
as "sufficient" evidence of
carcinocenicity on a case by case basis.
In the March. 1988 letter reviewing
tetrachloroethylene issues, the EPA
Science Advisory Board concurred with
the Agency's criteria for evaluating
mouse liver tumor responses.
(2) Peroxisome Proliferation. In the
case of PCE, peroxisome proliferation
has been proposed as a plausible
mechanism for mouse liver tumor
development Although PCE and
metabolite trichloroacetic acid (TCA)
induce peroxisome proliferation and
tumors in the mouse liver, a cause and
effect relationship is not thereby,
defined. While peroxisome proliferation
may have a role in mouse liver tumor
formation, the role is undefined. Other
plausible mechanistic hypotheses exist
including those associated with
genotoxicity. There may be multiple
mechanisms involved in mouse liver
tumor formation. At the present time,
EPA maintains the view that mouse liver
tumon are relevant for inferring a
potential for human health hazard
unless thsre is more definitive evidence
to the contrary.
(3) Mor.onucJaar Cell Leukemia.
Mor.onuciear cell leukemia, a neoplasm
that has been characterized biologically
and pathologically, was seen in both
male end female rats exposed to PCE.
Overall leukemia rates were statistically
significant in the males and marginally
so in females. When stage 3 Icukcmias
were counted, positive trends and
significant increases in male and female
rats were seen.
PCE caused a dose-related increase in
severity of mononuclear bukemia and
shortened the ticie-to-tumnr in female
rata. One commentcr questioned the
relevance of this tumor to humans. EPA
does not consider it appropriate to rule
out a rodent neoplasm simply because it
has no exact human counterpart. Site
concordance is not a requirement for
relevancy in the inference of hazard
potential.
Although a statistically significant
increase in tumor incidence for a tumor
having a high concurrent background
tumor incidence is consistent with
theory of promotion, this observation
does not identify the actual mechanism.
and thus several other plausible
mechanistic theories of PCE-induced
leukemia development can not be ruled
out
A statistically significant increase In
tumor incidence cannot be arbitrarily
dismissed without firm evidence
showing that mononuclear cell leukemia
in rats is a type of tumor response
isolated to this species and not relevant
to other potential tumor endpointc in
other species. Rather. EPA assumes that
the experimental animal evidence
identifies the potential for a
carcinogenic response in lumans unless
there is evidence to the contrary.
(4) Male Rat Kidney Tumor. PCE
increases the occurrence cf an
uncommon renal tubular cell tumor in
male rats. Recent research and
conventional toxlcological thinking have
suggested at least three plausible
explanations for the tumor occurrence,
i.e.. the presence of a unique male rat
renal protein, aipha-2u-globulin;
presence of a secondary metabolic
pathway which produces a genotcouc
compound in the kidney; and chronic
nephrotoxicity and cellular regeneration
independent of the aipha-2u-globulia.
The EPA is presently developing criteria
which will define a weight-of-evidence
approach for evaluating, on a case by
case basis, the role of alpha-2u-globuiin
in rat kidney tumor formation. For
instance, if the PCE data are
subsequently judged to be the only
definitive explanation for ths occurrence
cf male rat kidney tumors, this turner
endpoict may have minimal relevance
for human heailh hazard assessment.
This can be further evaluated by EPA as
criteria and PCE-spocific data become
available.
Given the presence of other plausible
mechanistic explanations, and the
currently incomplete picture about tv:e
role of the FCE-rat kidney protein. EPA
virws the rat kidney tumor endpoint to
be indicative ot PCE exposure and
relevant for consideration in the overall
weight of evidence for potential PCE
human health hazards.
Consequently, based on the
information available to the Agency end
the public comments received on the
May, 1Q89 proposal, EPA for the reasons
cited above continues to place
tstrechiaroethylene in Category I and
promulgates an MCLG of zero.
h. Toluene.
EPA proposed an MCLG of 2.0 mg/1
for toluene in the November 1983
proposal and Again in the May 1839
proposal based on a NOAEL of 1,120
mg/'m3 from an animal study.
Public Comments. Two commenters
submitted information in response to
EPA's proposal for regulation of toluene.
The major health effect issueo raised are
(1) use of rat ventilatory volume and
body weight in calculating the rat total
absorbed dose instead of human
ventilatory volume and body weight
and (2) use of a recently available 13-
week National Toxicology Program
(NTP) oral administration study rather
than the inhalation study used by EPA.
EPA Response. EPA agrees with the
commented that the rat ventilatory
volume and body weight instead of that
of humans, be used for the calculation of
total absorbed dose. EPA also agrees
with the suggestion by the commenter
that the NTP 1989 oral administration
study is acceptable for the derivation of
the MCLG, because it is preferable to
use valid oral studies, if available, for
the calculation of the MCLG.
In the NTP study, groups of rata were
administered toluene in corn oil at
dosage levels of 0. 312. 625.1.250, 2.500.
or 5,000 mg/kg for five days/week for 13
weeks. Liver-to-brain ratio was
increased (p < 0.05) in males receiving
the 625-mg/kg dose. This study
established a NOAEL of 312 nig/kg,
adjusted to 223 mg/kg/day for exposure
of five days per week. From this dose,
an RiD of 0.2 mg/kg/day and a DWHL of
7 mg/1 were determined.
Calculations uning the NTP otudy
result in the MCLG for toluene
decreasing from 2 mg/i (the proposed
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Federal Register / Vol. 58, No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
543
value) to 1 mR/1. Thsrefore, for the
reasons stated above. EPA places
toluc-ne in Category III end promuleates
en ivlCLG of 1 mg/l.
;'. Xylenes. EPA proposed an MCLG of
10 .T.n/1 (rounded from 12 mp/!) for
vvlenns. EPA's proposal cf 10 raa/1 was
baced on the NTP study involving the
admL-iistration of 0, 250. or 500 mg/kg
:• rienss in corn oil by gavage to groups
oi rets of each sex for 103 weeks.
Pdbiic Comments. A total of six
individuals or organizations provided
comments in response to the MCLG
proposal regarding xylenes. Three
cr-rnmanters felt that EPA should not
round the proposed MCLG for xylenes
down from 12 mg/l to 10 Kg/1. One
commenter felt that given the
uncertainty of the data presented in the
NTP study and the lack of clear
difference between the administered
dosages. EPA should have considered
the low dosage (250 mg/kg) in the NTP
study as the LOAEL rather than the
NGAEL Another commenter stated that
the NTP study of rats given xylenes in
com oil by gavage for 103 weeks was
not an appropriate study for the MCLG
for xyienes and suggested a teratogcnic
study in animals instead.
EPA Response. EPA believes the
rounded figure was appropriate because
using more than one significant figure
would have implied a degree of
precision that was not warranted given
the large uncertainty factor (100) that
was used in deriving the MCLG. EPA
considered the low dosage of 250 mg/kg
from the NTP study in rats as the
NOAEL since the mean body weights of
low-dose and vehicle control male rats
and those of dosed and vehicle control
female rats were comparable. EPA also
considered that the NTP oral study in
animals was more representative of
xyiene s toxicity in Drinking water than
was the inhalation teratogenic study
(Mirkova et al., 1983) suggested by the
commenter The NTP oral study in
animals entailed 103 weeks of exposure
to xylenes as compared to only 21 days
cf exposure to xylenes via inhalation.
Available cancer information on xylenes
has been reviewed by EPA and was
found to be inadequate for determining
potential csrcinogenicity in humans.
For these reasons, EPA places xylenes
in Category HI and promulgates an
MCLG of 10 mg/l.
6. Pesticidea/PCBs MCLCa
a. Alachlor. EPA proposed an MCLG
cf zero for alachlor in the May 22.1989
proposal. The MCLG was based on
sufficient evidence of carcinogenicity in
animals (classification of Group B2 by
EPA guidelines: Probable human
carcinogen) in the November 13.1985
Federal Register Notice. No new data
that change the conclusions presented in
that notice have become available since
its pubiiqation.
Public Comments. EPA addressed the
public comments received to the
previous proposal of November 13.1385
in the Federal Register Notice of May 22,
1339. In response to tnis 1939 notice, one
ccmmenter ca the MCLG for elachlor
indicated that EPA should consider
establishing a value other than zero as
the MCLG for B2 carcinogens. The
commenter indicated that although the
Agency classified alachlor in Group B2,
this chemical is unlikely to cause cancer
in people under usual conditions of
exposure. The commenter urged the
Agency to consider the modification of
its "standard" approach in quantitative
risk assessment in the case of aiachicr
and use the weight-to-weight
extrapolation instead of "surface area
correction" to extrapolate risk from
animal to human.
EPA Response. EPA believes there is
sufficient data to conclude that alachlor
is carcinogenic in animals since the
compound was shown to bs
carcinogenic in both rats and mice. EPA
therefore has classified alachlor in
Group B2: Probable human carcinogen.
EPA's policy in the calculation of the
quantitative risks for carcinogens is
based on the weight-to-surface
extrapolation from animal to human
data (U.S. EPA Cancer Guidelines, 1988).
Accordingly, EPA places alachlor in
Category I and an MCLG of zero is
promulgated.
b. Atrazine. EPA did not propose an
MCLG for atrazinc in the November 13.
1985 Federal Register Notice due to
limited toxicological data on the
chemical at that time. However, since
then, sufficient new data became
available to EPA to propose an MCLG
for atrazine in May 1989.
Accordingly, EPA proposed an MCLG
of 0.003 mg/l for atrazinc in the May 22,
1989 proposal. The MCLG was derived
from a DWEL of 0.2 mg/l, applying a 20
percent contribution from drinking
water and an additional 10-fold
uncertainty factor by classifying
atrazine in Group C.
The proposed MCLC was based ursn
non-carcinogenic effects in-a one-y^r
dog feeding study (Ciba-C-eigy, 1937. No.
852003 and Pathology Report No. 7048.
MRID 40313-01). A NOAEL of 0.5 mg/
kg/day was identified based upon the
finding of discrete myocardial
degeneration at the highest dose level
(43 mg/kg/day) and findings at the 5.0
mg/kg/day dose level that suggested a
trend toward the development of the
cardiac pathology seen at the higher
dose.
After the May proposal, a detailed
analysis of these cardiac effects
identified by Ciba-Geigy in 1989 (MRID
412938-01) was reviewed by the Agency.
The review resulted in EPA increasing
the NOAEL from 0.5 mg/kg/day to 5.0
mg/kg/day. Subsequently, the existing
study supporting the dog study, the two-
generation reproduction study in rats
with a NOAEL of 0.5 mg/kg/day and a
LOAEL of 2.5 mg/kg/day (Ciba Geigy,
1987. MRID 404313-03). became the
basis for the RfD. DVVEL. and MCLG
calculations. Consequently, the RfD for
ctrazine remains the same at 0.005 mg/
kg/day (based on the uss of a NOAEL cf
O.o mg/kg/day and a 100-fold
uncertainty factor). Both ths DWEL and
MCLG remain unchanged a! 0.2 r:g/'l
and 0.003 mg/l, respectively.
In this two-generation study, atrazinc
was mixed in the diet at 0,10, 50, and
500 ppm (equivalent to 0, 0.5. 2.5. and 25
mg/kg/dayj. Pup weights et postnatal
day 21 were statistically significantly
reduced at the two higher doses, 2.5 and
25 mg/kg/day, in the second generation.
The NOAEL in this study is also
supported by adverse findings at dose
levels higher than C.5 mg/kg/day in both
the rat chronic feeding/oncogcnic study
by Ciba-Geigy (1986, Study *401-1102,
Accession Nos. 26714-2G2727) and the
two-year feeding study in dogs by
W'oodard Research Corporation (1964,
MRID 0059213).
Public Comments. Four individuals or
organizations commented on the MCLG
and MCL proposal for atrazine. Two
commenters agreed with EPA on the
proposed MCLG and MCL: however, one
cf these two commenters indicated that
when new data become available to the
Agency, the proposal should include an
update of the MCLG and MCL values
based on this new information. This
commenter also indicated that the
Agency's citation of adverse effects on
liver and kidney of dogs and rats at high
levels as the basis for setting the MCL at
3 ppb is inconsistent with the statement
on page 22081 of the May 22.1969
Federal Register Notice which says the
absence of cardiac lesions in dog3 at a
dose of 0.48 mg/kg/day provided the
basis for the MCL The commenter noted
that since these effects occurred at high
levels only, they are not the primary
effect of atrazine: therefore, the
statement on page 22081 should ba
corrected to reflect the effects noted at
the lowest effect level. The third
commenter was concerned with the
selection of the NOAEL for the
calculation of the DWEL: he indicated
that the Agency should use the higher
NOAEL of 0.5 mg/kg/day in the rat
study instead of the lower NOAEL of
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3544 Federal Register / Vol 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
0.35 mg/kg/day in the two-year dog
study to calculate the MCLG for
atrazine. The fourth commenter
indicated that strazine should be
classified i:: Group B2 instead of C
becsuse. in his opinion, the rat study
provided "sufficient evidence" of
carcinoser.icity; therefore, the MCLG
r.houid be zerc. In addition, he argued
that the Agency's rationale for
classifying atrazine ir. Group C [see 54
FR 22062 at 22CB2] is misleading and
:,!5O'Jid have- read: "Limited evidence of
ciircinognnicity, which means that the
data c^ijgcst a carcinogenic effect but
ore limited bjcause (aj the studies
involve a single species, strain, or
experiment and do not meet criteria for
f.efficient evidence (see Se.-tion
IV.D.I.c:: ' ' •) (52 FR 23099. emphasis
LJCL'dl."
EPA Response. New information
1 ecame available to the Agency on the
1937 cne-ycar dog study (Ciba-Geigy,
MR!D 40312-01) that was used in the
calculation of the RfD and DWEL This
r.ew information (Ciba-Geigy, 1989.
.'•.1RID 412938-01) caused the NOAEL in
this study to change from 0.5 mg/kg/day
to 5.0 mg/kg/day. Since the Agency
usually uses the highest NOAEL in the
most sensitive species to calculate the
RfD, the two-generation rat study
discussed above with a NOAEL of 0.5
mg/kg/day {Ciba-Geigy. 1987, MRID
404313-03) was selected as the most
appropriate study to determine the RfD.
Since the new RfD is the same in value
as the previous RfD, which was
calculated from the one-year dog study
in the May 22,1989 proposal, the DWEL
and MCLC will remain as proposed at
0.2 and 0.003 mg/1, respectively.
In response to the comment that
atrazine should be classified in Group
B2. the Agency disagrees based on the
fact that the increased incidence of the
mammary tumors (a tumor with a
generally high spontaneous background
in the rat) was noted only in one species
and one strain of rat.
Accordingly, EPA places atrazine in
Category II and promulgates an MCLG
of 0.003 mg/1 for atrazine, as proposed in
the May 1989 proposal based on the
changed basis for the RfD. as discussed
above.
c. Carbofuran. EPA proposed an
MCLG of 0.04 mg/1 for carbofuran in the
May 22.1989 proposal. The MCLG was
darived from a DWEL of 0.2 mg/1,
applying a 20 percent contribution from
cririking water. Carbofuran is classified
ir. Group E (no evidence of
carcinogenicity) by EPA. The MCLG of
0.036 mg/1 in the November 13.1985
proposal was rounded ir. the May 1989
proposal to 0.04 mg/1. No new data that
would change the conclusions presented
in that notice have become available
since its publication.
Public Comment. EPA previously
addressed the public comments received
in response to the previous proposal of
November 13,1985 in the Federal
Register notice of May 22. 1989. In
response to this notice of 1S89. three
individuals or organizations commented
on the MCLG proposal for carbofuran.
One commenter indicated that the
proposed standard does not protect from
immune system depression in humans.
Another commenter indicated that
additional negative immunologicai
studies were not discussed in the
carbofuran criteria document, in
addition, this commenter provided
ccrrections and editings to the
chemistry, occurrence and fate sections
of t.'i.e criteria document. A third
commenter requested a change in the
NOAEL used in the calculation of the
RfD from 0.5 to 0.25 based on
cholinesterase activity, thus indicating
that the MCLGs should be two-fold
lower.
EPA Response, EPA addressed the
issue of cholinesterase inhibition as the
endpoint of toxicity in a special forum.
The 15 to 20 percent inhibition in blood
cholinesterase activity may be
considered a LOAEL This level of
inhibition may be considered adverse or
non-adverse on a case-by-case basis
depending on the toxicological profile of
the chemical. In the case of carbofuran,
the NOAEL is based on the effects noted
on both the reproductive and nervous
systems. The chosen NOAEL of 0.5 mg/
kg/day was the appropriate NOAEL for
both systems; the uncertainty factor
applied to this NOAEL is 100-fold,
resulting in an MCLG of 0.04 mg/1. If the
lower dosage of 0.25 mg/kg/day was
selected as the basis of these
calculations, the applied uncertainty
factor (UF) would have been 10-fold
only because a larger UF would not be
justified based on the available toxicity
profile of carbofuran. Therefore, the
MCLG would have been higher than 0.04
mg/1. not two-fold lower. The choice of
the NOAEL of 0.5 mg/kg/day in the dcg
study and the application of a 100-fold
UF were more protective to public
health because the NOAEL was based
on both endpoints of toxicity, tcsticular
effects and blood cholinesterase
inhibition, with an appropriate selection
of the UF as necessitated by the severity
of these endpoints.
In response to the commenters on
immunotoxicity, EPA believes further
research in this area is needed before
any conclusion can be made on the
effect of carbofuran on this endpoint.
Consequently, EPA places carbofuran in
Category III and an MCLG of 0.04 mg/1
is promulgated.
d. Chlordane. EPA proposed an MCLG
of zero for chlordane based on sufficient
evidence of carcinogenicity in animals
(Group B2). While the proposed MCLG
of zero is based on the csrcinogenicity
cf chlordane, EPA provided a revised
DWEL of 0.002 mg/i based on the results
cf a newer chronic rat Qietary study
(Yonemura et al., 1983: 30-month chronic
toxicity and tumcrigenicity test in rats
by chlcrdane). This DWEL was
calculated assuming an uncertainty
factor of 1,000 !100 for the inter- and
intrasoecies differences and 10 for the
lack of a seccnd chronic toxiciiy/
reproductive study) and consumption of
2 liters of water per tiay by a TO-kg
adult.
Public Cciimsr.t. One ccmrnenter
stated that (1) chlordane was not
properly considered a "E2" carcinogen
si^ce the EPA Carcinopsn Assessment
Group (GAG) report (1986) ccu'd not
justify such a classification: therefore
the basis for a proposed MCLG of zero
was incorrect, and (2) EPA incorrectly
used an additional safety factor cf 10
because of a lack ef a second chronic
study in the derivation of the DWEL for
chlordane.
EPA Response. According to EPA's
guidelines, a Group B2 classification
(probable human carcinogen) is used
when there is sufficient evidence of
carcinogenicity in animals and
inadequate data in humans. EPA
considers that chlordane is correctly
proposed as a Group B2 carcinogen
because a number of rodent studies
(with four strains of mice of both
genders and F344 male rats) had clearly
demonstrated the induction of liver
tumors in animals following
administration of chlordane. In addition.
three compounds structurally related to
chlordane. aldrin. dieldrin. and
chlorendic acid have produced liver
tumors in mice. Chlorendic acid has also
produced liver tumors in rats.
EPA has correctly applied an
additional safety factor of 10 in the
derivation of the DWEL due to the lack
of a second chronic study in animals.
EPA believes that the lack of adequate
chronic toxicity data and the lack of
data on reproductive effects require an
additional factor of 10. Therefore, EPA
places chlordsne in Category I and an
MCLG cf zero is promulgated based on
sufficient evidence of carcinogenicity in
animals and inadequate data in humans.
e. 1.2-Dibror.io-3-chloropropcne
(DBCP). EPA proposed an MCLG of zero
for 1.2-dibromo-3-chloropropane in the
May 22.1989 proposal. The MCLG was
based on sufficient evidence of
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Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3545
•;2rcinrgenicity in enimals
[classification in Group E2 by EFA
•v-ide'ir.sc: Probable human carcinogen)
h ihs November 13.1385 Federal
P.ojister r.otice. No new data which
change tne conclusions presented in that
notice have become available since its
publication.
Public Co^imenis, EPA addressed the
pubhc comments received in response to
the previous proposal of November 13.
1985 in the Federal Register Notice of
May 22,1339. One commenter stated
that there is valid epidemioiogical
evidence to show that l,2-dibromo-3-
chloropropane is not a human
carcinogen and that animal studies
unreliably predict carcinogenicity.
Consequently, this commenter
concludes overall evidence adequately
supports downgrading l,2-dibromo-3-
chloropropane from Croup B2 to Group
C by the EPA guidelines, if this is done,
the commenter recommends setting the
MCLG on the basis of non-carcinogenic
toxic effects with en adequate margin of
safety. The commenter states that if
EPA continues the Group E2
classification for 1.2-dibromo-3-
chloropropane. then the MCLG should
be set at a level corresponding to a
lifetime cancer risk of 10"* to 10~* or on
the basis of noncarcinogenic toxic
effects with an added margin of safety.
Using EPA'a risk assessment, the
commenter concludes that an increased
cancer risk in the range of 10~* to 10~5
would be at least 0.001 mg/1
(corresponding to a risk of 4 x 1G~5);
therefore, the commenter feels the
MCLG should be set at 0.001 mg/1 or
greater. The commenter believes EPA's
proposed MCL of 0.0002 mg/1 is
unreasonably low considering the
carcinogenic potential and the
r.ommenter's position that the half-life of
1.2-dibrorno-3-chloropropane in water
guarantees that most water systems will
reach the proposed MCL through natural
processes within 15 years. Another
commenter agreed with the comment
that 0.0002 mg/1 is unreasonably low for
en MCL and felt that an MCL for 1,2-
dibromo-3-chloropropane should be 0.05
tr.g/1 or higher.
EPA RcE3or.se. Regarding the
epidemic-logical data for l,2-dibromo-3-
chloropropene, EPA believes the
epidemiology data base is inadequate to
either refute or demonstrate that 1.2-
dibromo-3-chloropropane causes tumors
in humans. EPA believes there is
sufficient data to conclude that 1.2-
dibromo-3-chloropropane is
carcinogenic in animals since the
compound has bsen shown to be
carcinogenic in both rats and mice. EPA
therefore has classified 1.2-dibromo-3-
chlorcpropane in Group E2: Probable
human carcinogen. Consequently. EPA
places 1.2-dibromo-3-chloroprcpane in
Category i and en MCLG of zero is
promulgated.
f.2.-',-D. EPA proposed an MCLG of
C.C7 mg/1 for 2.4-D in the November 1035
proposal and again in May 1929 based
en adverse effects on the liver end
kidney in tost animals. EPA based this
MCLG on a NOAEL of 1 rr.g/kg/day, sn
uncertainty factor of 100, and in a
assumption that a 70-kg adult consumes
2 liters cf water per day. EPA also
assumed that 20 percent of total
exposure of 2,4-D would be from
drinking water. No new relevant data
that change EPA's conclusions have
become available since publication of
the proposals.
EPA also stated dial it would consider
adopting an MCLG of 0.02 mg/1 for 2.4-
D, based upon the same study es v/as
used to calculate the proposed MCLG,
with the application of sn additional
uncertainty factor of 3 to the
calculations. This uncertainty factor
would be applied to account for the fact
that supporting long-term data in dogs
were net available for 2,4-D.
Public Comments. One commenter
stated that EPA ignored the two
National Cancer Institute (NCI) studies
linking exposure to 2,4-D with an
increase of non-Hodgkin's lyrr.phoma,
and that since IARC classified
chlorophenoxy herbicides in Group B2
(limited evidence of carcinogenicity in
humans). EPA should do likewise.
EPA Response. EPA did not ignore the
two epidemioiogical studies published
by NCI that reported the possible
association of phenoxy herbicides (2,4-D
is a member of the class) with cancer.
Since the studies dealt with a class of
crimnounrls. i! is imnractical to
specilicaiiy li:ik 2,1-D as a probsb',2
carcinogen, in addition, the
contaminants in phenoxy herbicides
further cloud the results of these studies.
EPA's proposal for the regulation of
2. 1-D was basnd on inadequate data for
the cancer classification and its effects
of 2.4-D on the liver and kidney.
Controversy regarding the cancer
classification cf 2.-1-D has onsen
because of the recently published
epidemioiogical studios on phenoxy
herbicides, a class of compounds of
which 2,4-D is a member. EPA's Office
ol' Pesticide Programs (OPP) published a
notice in the Federal Register (October
13.1989) stating that an external panel
of experts would be convened to advise
the Agency en the carcinogenic
potential of 2.4-D. However, until the
panel of experts convenes and the
Agency accepts its results, EPA
continues to categorize 2,4-D as n
category III contaminant. Ccnsequrr.tly.
EPA is promulgating the MCLG of 0.07
ng/i for 2.4-D as proposed.
y. Heptach.'or/Heptachlor Epoxids.
EPA proposed an MCLG of zero fcr both
heptachlor ond heptachlor cpoxide
based on sufficient evidence of
•:arc:nc«?2nicity (Group B2) in arrivals.
Since the May proposal, EPA has
revised the DVVELs for heptachlor and
heptschlor spoxide. A revised DVVEL cf
0.02 ms/'l (rounded from 0.0175 mg/1)
was calculated for heptachlor. For
heptachlor epoxide. a revised DV/EL of
0.0004 rne/1 was derived. These
revisions of DWELs for heptachlor and
hepiachlcr epoxide do not affect EPA'a
conclusions about carcinogenicity of
these chemicals: ho-.vever, they are
presented to provide mcrs information
en health effects.
Public Comments. One organize :ion
provided comments in response to the
N'CLG proposal regarding heptachlor
and heptachlor epoxide. The coinmenter
stated that heptachlor and heptachlor
epoxide have been incorrectly classified
as Group B2 carcinogens and that EPA's
Carcinogen Assessment Group report
(1936) could not be used to justify such a
classification.
EPA Response. According to EPA's
guidelines. Group B2 (probable human
carcinogen) is used when there is
sufficient evidence of carcinogenicity in
animals and inadequate data in humans.
These guidelines also state that mouse
liver tumor data may be used to support
sufficient evidence of carcinogenicity.
The evaluation cf the carcinogenic
potential of heptachlor and heptachlor
cpoxide was based on a sufficient
number of rodent studies in which liver
carcinomas were induced in two sliains
cf mice of both genders and in CFN
female rats.
Consequently, as discussed above,
EPA places both heptachlor and
heptachlor epoxide in Category i and
promulgates an MCLG of zero as
proposed.
.":. Lir.cicr.e. EPA reproposed an MCLG
of 0.0002 ma/1 for llndane based upon a
DV/EL of 0.01 mg/1. an additional
uncertainty factor of 10 since lindar.e
was categorized as a category II
contaminant (limited evidence of
carcinogenicity via drinking water
ir.zestion). and a 20 percent contribution
from drinking water. No new data were
received that change tha conclusions
presented in the November 1985
proposal.
Public Comment. One commenter
stated that the MCLG should be zero for
lindane since lindane was classified as
Group C (possible human carcinogen).
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EPA Response. The only evidence of
carcinogenicity for lindane was in mice
and available data do not permit
definitive decisions on its oncogenic
potential in rats. Since this effect has
been reported in only one species.
lindane was placed in Category II. and
the MCLG values for Category li
substances are set based on the RfD. An
MCLG of C.0002 mg/1 for iindane is
promulgated as proposed.
/. Mslhoxych'Or. EPA proposed an
MCLG of 0.4 mg/1 for methoxychlor
based on a rat study which identified a
NOAEL of 5 mg/kg/day and applied an
uncertainty factor of 100. However, it
was also stated in the EPA proposal cf
May 22,1989, that a recent teratology
study in rabbits for methoxychlor was
under review by OPP. No comments
were received during the comment
period.
Following the review by the OPP sad
EFA's RfD Workgroup, an RfD of 0.005
rr.g/kg/day for methoxychlor was
recommended based on this teratology
study in rabbits (5-7-90). In this
teratology study, a NOAEL of 5 mg/kg/
day was identified and an uncertainty
factor of 1.000 was applied consisting of
100 for the inter- and intraspecies
differences and an additional factor of
10 for the steep dose-response curve and
the incompleteness of the data base on
chronic toxicity. EPA has placed
methoxychlor in Category III but for
reasons discussed above the MCLG was
changed from the 0.4 mg/1 level, as
proposed, to 0.04 mg/1 in today's rule.
/ PolychlorinatedBiphenyls (PCBs).
EPA proposed an MCLG of zero for
PCBs in the November 1985 proposal
and again in May 1989 based on its
classification as a Group B2 carcinogen
(sufficient animal evidence, inadequate
human evidence).
Public Comments. Several
commenters submitted information in
response to EPA's May 1989 proposal for
regulation of PCBs. Major health effects
issues were (1) inadequate evidence of
carcinosenicity in humans. (2) extent of
chlorination and carcinogenicity. i.e.,
only PCBs with 60 percent plus
chlorinated mixtures have been reported
to be carcinogenic in animals, and (3)
non-mutagenicity of PCBs. One
commenter supported EPA's MCLG of
0.5 fig/1 PCBs in drinking water. One
commenter recommended exploring the
feasibility of regulating PCBs based on
relative toxicity of PCB congeners, citing
the article, "Environmental Occurrence,
Abundance and Toxicity of
Polychlorinated Biphenyl Congeners:
Considerations for a Congener Specific
Analysis" (McFarland and Clarke.
Environ. Health Perspect.. Vol. 81. May
1989, p. 225).
EPA Response. EPA agrees with the
commenters that there is inadequate
evidence of carcinogenicity of PCBs in
humans. However, there is sufficient
evidence of carcinogenicity of PCBs in
animals, which places PCBs in Group B2
according to the Agency's cancer
guidelines. Therefore, according, to EPA
policy, the MCLG for PCBs is zero. The
proposed MCL is 0.0005 mg/1, the
practical quantification limit.
PCBs that are 60 percent chlorinated
have been reported to be carcinogenic in
animals, while PCBs with a lower
chlorine concentration (chlorine 54
percent) have produced cancer in
animals that was not statistically
significant. PCEs arc complex mixtures
of chlorinated biphenyls, which can
contain up to 209 possible isomers: the
toxicity of these has not been fully
characterized. Therefore, it appears
reasonable to regulate PCBs as a class
of compounds with a cancer
classification of Group B2. FDA also
regulates PCBs as a class of compounds
rather than individual congeners.
EPA agrees that PCBs are not
mutagenic in a bacterial test system:
however, this method does not respond
to chlorinated hydrocarbons, including
PCBs. In addition, a negative mutagenic
test does not detract from the
carcinogenic potential of PCBs.
Therefore, for the above reasons, EPA
places PCBs in Category I and
promulgates an MCLG of zero.
7. Other Synthetic Organic Contaminant
MCLCs
a. Aery/amide. EPA proposed an
MCLG of zero for acrylamide in the May
22,1989 proposal based on a B2
classification for the chemical.
Public Comments. EPA reponded to
the public comments received in
response to the previous proposal of
November 13.1S85 in the Federal
Register Notice of May 22,1339. One
commenter questioned the B2
classification citing the results of a new
acrylamide bioassay by American
Cyanamid which indicated that mcuse
screening studieo were not repeatable,
that human epidemiology studies were
negative, that acrylamide does not
produce point mutations, and the
acrylamide reacts preferentially with
protein.
EPA Response. The current B2
classification for acrylamide is based
primarily on the Johnson et al. study
(Toxicol. Appl. Pharmacol. 85:154-169.
1988). In this study, the authors reported
increased incidences of scrotal
mesotheliomas, mammary gland tumors,
thyroid adenomas, uterine
adenocarcinomas. clitoral gland
adenomas, and oral papillomas. In
agreement with the Johnson et al. study.
the more recent American Cyanamid
study reported statisticai'y significant
increases in the incidences oi mammary
giand tumora (fibroadencmas or
Lbroadenomas and carcinomas
combined), scrotal mesotheiiornas, and
thyroid neoplasms (adenomas or
adenomas and carcinomas combined) in
both sexes. The utsrine
adenocarcinomes, ciitoral glar.d
adenomas, and oral pap-niomas
observed in the Jolmson ct a:, study
were not found to be increased in the
American Cyanamid study. However.
there was a positive dose-related trend
in the incidence of malignant reticulosis
in the brains of females and an
increased incidence of astrocytomas
(CNS glial tumors) in both sexes at the
highest dose level in the American
Cyanamid study. After reviewing this
study, the Agency has concluded that
both studies demonstrate that
acrylamide administration resulted in
carcinogenicity at more than one site in
rats.
Since there are two positive cancer
bioassays, the fact that there is some
disagreement among the Bull et al.
studies (Cancer Res. 44:107-111,1984a.
and Cancer Lett. 24:208-212,1984b) and
the Robinson et al. study (Environ. Hlth.
Perspect. 88:141-145.1986) would not
affect the classification of acrylamide.
EPA has reviewed two human
epidemiology studies (Collins, American
Cyanamid Co., 1984. and Sobel et al., Br.
J. Ind. Med. 43:785-788.1988) and found
them to be inadequate for determining
the potential carcinogenicity of
acrylamide in humans.
Athough acrylamide does not induce
point mutations, it is a clastogenic agent,
inducing chromosomal aberrations.
dominant lethality, sister-chromatid
exchanges, and unscheduled DNA
synthesis (Dearfield et al.. Mut. Res.
195:45-77.1988). Furthermore, the results
of a mouse heritable translocation study
(Shelby et al.. Environ. Mutagen. 9:3263-
368.1987) has shown that acrylamide is
an effective inducer of translocations in
postmeiotic germ cells, suggesting that
acrylamide may pose a heritable risk
concern in mammals.
While it is certainly correct to state
that acrylamide preferentially reacts
with protein (Sega et al.. Mut.. Res.
216:221-220.1989). it also reacts with
nucleic acids in vivo (Carlson and
Weaver, Toxicol. Appl. Pharmacoi.
79:307-313.1979) and in vitro (Solomon
et al.. Cancer Res. 45:3465-3470.1985).
Accordingly, it is not possible to rule oui
the possibility of acrylamide-DNA
interaction. Due to the two positive
acrylamide bioassays and other data.
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Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3547
T.PA retains a B2 classification for
•crylamide and places it in Category I
v.'ith an MCLG of zero.
B. Establishment of MCLS
1. Methodology for Determination of
MCLs
The SDWA directs EPA to set the
MCL "as close to" the MCLG "as is
feasible." The term "feasible" means
"feasible with the use of the best
technology, treatment techniques, and
other'mcans. which the Administrator
finds, after examination for efficacy
under field conditions and not solely
under laboratory conditions, ere
available (taking costs into
consideration)." (SDWA section
1412(b)(£)). Each National Primary
Drinking Water Regulation that
establishes an MCL lists the technology,
treatment techniques, and other means
which the Administrator finds to be
feasible for meeting the MCL (SDWA
section 1412(b)(6)).
The present statutory standard for
"best available technology" (BAT) under
1412(b)(5) represents a change from the
provision prior to 1986, which required
EPA to judge feasibility on the basis of
"best technologies generally available"
(BTGA). The 1988 Amendments to the
SDWA changed BTGA to BAT and
added the requirement that BAT must
be tested for efficacy under Held
conditions, not just under laboratory
conditions. The legislative history
explains that Congress removed the
term "generally" to assure that MCLs
"reflect the full extent of current
technology capability" [S. Rep. No. 58,
99th Cong.. 1st Sess. at 6 (1985)]. Read
together with the legislative history,
EPA has concluded that the statutory
term "best available technology" is a
broader standard than "best technology
generally available." and that this
standard allows EPA to select a
technology that is not necessarily in
widespread use. as long as it has been
Held tested beyond the laboratory. In
addition. EPA believes this change in
the statutory requirement means that the
technology selected need not .
necessarily have been field tested for
each specific contaminant. Rather. EPA
may project operating conditions for a
specific contaminant using a field tested
technology from laboratory or pilot
systems data.
Based on the statutory directive for
setting the MCLs. EPA derives the MCLs
based on an evaluation of (1) the
availability and performance of various
technologies for removing the
contaminant and (2) the costs of
applying those technologies. Other
technology factors that are considered
in determining the MCL include the
ability of laboratories to measure
accurately and consistently the level of
the contaminant with available
analytical methods. For Category I
contaminants, the Agency also
evaluates the health risks that are
associated with various levels of the
contaminants, with the goal of ensuring
that the maximum risk £t the MCL falls
within the I"4 to 10"'risk range that the
Agency considers protective of public
health, therefore achieving the overall
purpose of the SDWA.
EPA's initial step in deriving the MCL
is to make an engineering assessment of
technologies that are capable of
removing a contaminant from drinking
water. This assessment determines
which of those technologies are "best."
EPA reviews the available data to
determine technologies that have the
highest removal efficiencies, are
compatible with other water treatment
processes, and are not limited to a
particular geographic region.
Based on the removal capabilities of
the various technologies, EPA calculates
the level of each contaminant that is
achievable by their application to large
systems with relatively clean raw water
sources. [See H.R. Rep. 1185. 93rd Cong.,
2nd Sess. at 13. (1974); 132 Cong. Rec.
S6287. May 21,1986. statement of Sen.
Durenberger.)
When considering costs to control the
contaminants in this rule, EPA analyzed
whether the technology is reasonably
affordable by regional and large
metropolitan public water systems [see
H.R. Rep. No. 93-1185 at 18 (1974) and
132 Cong. Rec. S6287 (May 21.1986)
(statement of Sen. Durengerger)]. EPA
also evaluated the total national
compliance costs for each contaminant
considering the number of systems that
will have to install treatment in order to
comply with the MCL The resulting
national costs vary depending upon the
concentration level chosen as the MCL
The more stringent the MCL the greater
the number of systems that may have to
install BAT in order to achieve
compliance. In today's rule. EPA has
determined that costs for large systems
and total national compliance costs at
the MCL are reasonably affordable and.
therefore, feasible. Therefore,
alternative MCLs were not considered.
The feasibility of setting the MCL at a
precise level is also influenced by
laboratory ability to measure the
contaminant reliably. EPA derives
practical quantitation levels (PQLs)
which reflect the level that can be
measured by good laboratories under
normal operating conditions within
specified limits of precision and
accuracy. Because compliance with the
MCL is determined by analysis with
approved analytical techniques, the
ability to analyze consistently and
accurately for a contaminant at the MCL
is impor-.ant to enforce a regulatory
standard. Thus, the feasibility of
meeting a particular level is affected by
the ability of analytical methods to
determine with sufficient precision and
accuracy whether such a level is
actually being achieved. This factor is
critically important in determining the
MCL for contaminants for which EPA
sets the MCLG at zero, a number which
by definition can be neither measured
nor attained. Limits of analytical
detection require that the MCL be set at
some level greater than the MCLG for
these contaminants. In these cases. EPA
examined the reduction capability of
BAT and the accuracy of analytical
techniques as reflected in the PQL to
establish the appropriate MCL level.
EPA also evaluates the health risks
that are associated with various
contaminant levels in order to ensure
that the MCL adequately protects the
public health. For drinking water
contaminants, EPA sets a maximum
reference risk range 10"' to 10"* excess
individual risk from for carcinogens at
lifetime exposure. This policy is
consistent with other EPA regulatory
programs that generally target this range
using conservative models that are not
likely to underestimate the risk. Since
the underlying goal of the Safe Drinking
Water Act is to protect the public from
adverse effects due to drinking water
contaminants. EPA seeks to ensure that
the health risks associated with MCLs
for carcinogenic contaminants are not
significant.
Below is a detailed discussion of the
Agency's response to the comments on
the proposed rule and how today's
MCLs were determined. EPA is
reproposing for public comment the
MCLGs and MCLs for aldicarb. aldicarb
sulfoxide, aldicarb sulfone. barium, and
pentachlorophenol due to a change in
the health basis for the standard.
However, regardless of the final
standards which are established, EPA
believes the BAT and analytical
methods promulgated today will not be
affected by the new standards.
Consequently, those requirements are
promulgated today.
2. Inorganic Analytical Methods
In the May 1989 notice, the Agency
proposed a list of analytical methods to
be used for measuring eight inorganic
chemicals (lOCs) that it considered
economically and technologically
feasible for monitoring compliance.
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These methods are promulgated todav
as proposed with the exception of the
revisions that will be discussed below
(sse Table 9). These methods were
selected based on the foiiowma factors:
(I) reliability (i.e.. precision/accuracy)
c.; the analytical results: (2) specificity in
the presence of interferences: (3)
availability of enough equipment ar.d
irsmed personnel to implement a
rational monitoring prosrara (i.e..
laboratory availability): (4) rapidity of
analysis to permit routine use: ar.U (5|
cost of analysis to water supply
systems.
Table 9 lists the analytical methods
lhat EPA is approving fcr use to comely
with the monitoring requirements. EPA
has updated the references to the most
recent editions of the manuals, including
the atomic absorption and emission
methods for metals; the transmission
electron microscope method for
ssjsstoe: and the coiorimetric.
••^eclrophotometric. potenuomctric. and
;cn chromatography methods for nitrate
and rutrite.
The reliability of analytical meihods
used for compliance monr.oring is
critical at the MCL Therefore, the
snalytical methods have to be evaluated
with respect to the accuracy or recovery
(lack of bias) and precision (good
reproducibility) at the range of MCL
When NPDYVRs ars revised or new
regulations are proposed, the Agency
examines all appropriate methodologies.
including any minor modifications of the
method that may have beer, approved
fcr limited use. and only those methods
which n-.eet all the necessary criteria are
proposed. Public comments on the
applicability of these methods are taken
into consideration when the rule is
finalized.
In viev of this, only the analytical
procedures specitied in this final rule
can be used fo* cortiplinnce monitoring
after th:s rule is promulgated. The
Agency is aware that minor
modifications to specific methods have
been previously approved for limited
use by various laboratories. These
approvals will cease upon the effective
date of this rule. New methods, new
applicctions of current methods, and
any modification to method approved in
the future will be published in the
Federal Register, thus making tnese
changes available to all laboratones.
c. Asbestos. Several commeziters
submitted comments expressing
concerns with the following: (1) The
expense of Transmission Electron
Microscopy (TEN!) analysis for asbestos;
(2) the number of laboratories available
with TEM capabilities: (3) the
quantitative analytical precision and
accuracy of the TEM method: and W the
absence of other asbestos methods on
the list of methods. EPA recognizes that
TEM analysis is somewhat more
expensive than other conventional
analyses for most anaiytes that are
regulated under the SDVVA. However.
the overall national cost should be
lessened because of the reduced number
cf systems effected by the monitoring
requirements after the vulnerability
assessment, resulting in a limited
number of samples for smlyses.
EPA believes that sufficient analytical
capacity will exist fcr those water
systems that are deemed vulnerable
because public water systems will have
approximately five years from
publication of the final rule to complete
the monitoring (i.e.. December 31,1335).
thus allowing the analytical capability
to develop. In addition. E?A is currently
particioating in a cooperative program
with the National Institute of Standards
and Technology (NIST) to certify a pool
of laboratories that can perform
asbestos analysis using the TEM
method.
A performance evaluation (PE) sample
is currently being developed by the
Agency to assess laboratory
performance usins the TEM method.
Furthermore, the EPA facility in Athens
has produced inierlaboratory and
intralsboratory (single laboratory)
studies to verify the method's
performance and capabilities.
Other asbestos analytical methods
were considered and evaluated but they
were found to be inadequate and
inferior to the TEM method. The Agency
has determined that TEM is the best
available technique because of its
specificity of asbestos fibers (chrysotile
versus amphiboie). its effectiveness in
distinguishing between asbeotoo and
nonasbeetos fibers, and its ability to
determine the number of fibern per
volume and fiber size (length and
width). Furthermore, the MCLG for
asbestos was assessed using data
resulting from TEM analyoeo. The
analysis of waterborne asbestos by
different techniques can yield radically
different results, unlike the methodology
of other anaiytes. EPA believeo it io
imperative to ensure comparability that
the analytical technique required for
monitoring water quality samples be the
same as that used to assess the MCLG.
EPA, however, continues to desire
additional screening methodology and
encourages the public to inform the
Agency when a potential technique may
exist. If additional methods become
available that meet the MCL
requirement EPA will promptly update
the rale to permit ahernatweo to the
TEM method.
b. Nitrate/Nitrite. Several
comment era addressed concerns about
the ability of laboratories to analyze
nitrite because cf its unstable charerter
er.ri associated analytical problems.
EPA evaluated the most recent available
data res'-ltinc frc:n Water Supply (WS)
FE studies ~022-GI5. in which vanous
approved methods wero used, to
determine laboratory performance fcr
nitrite. The acceptance limits calculated
from this data for the EPA, State, and
r.cn-EPA laboratories that participated
in the studies demonstrate successful
nitrite analyses as compared to the
acceptance limits of the other regulated
contaminants as summarized in table 12.
One commenter stated that there are
conflicting opinions whether to use
single (Waters method 8-1011) or dual
(EPA Method 300.0) column
chromatogrephy for nitrate analysis.
EPA evaluated data from a
comparability study for both of the
methods and concluded that they both
were successful in analyzing nitrate, i.e..
precision, accuracy, and acceptance
limits criteria were met
Some commenters also objected to the
deletion of the colcrimetric hrucine
method for nitrate from the iiet of
methods. EPA evaluated the most recent
available data from the Laboratories that
used the brucine method for WS PE
studies #020-025. The review of the data
demonstrated the inability of the
method to produce results that met the
acceptance limits criteria, than its
elimination from the list of approved
methods.
c. Other inorganic Analyses. Several
commenters stated that EPA Method
200.7 (Inductively Coupled Plassaa-
Atornic Emission Spectrometric Method
(ICP-AES1) witho-jt the appendix (EPA
Method 2G0.7A) is applicable for the
analysis of barium end chromium and
objected to its omission from the list of
methods. EPA concurs with this
assessment of the method and TCI!!
permit its use as an additional optional
method for the analysis of barium and
chromium. However, the appendix
(200.7A) must be followed in processing
drinking water samples prior to 1CP-
AES analysis for cadmium, because
Method 230.7 is not sensitive enough for
cadmium samples at the MCL level in
this rule.
Cne ccmrr.snter recommended the
deletion of the gaseous hydride EPA
Method 270.3 for selenium from the list
of methods because of its referral to a
method that is no longer cited. EPA
recognizes this inconsistency and has
deleted this method from the list of
approved methods becauce it in an
incomplete method that refeEsnces
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Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1S91 / Rules and Regulations
3349
Standard Methods (SM) 4MB in the 14th
edition for analytical details. SM 404B
has been replaced by SM 303E ir. the
15ih edition, which is dncidediy
improved and is on ths list of approved
.~3ihods.
Several conmenters objected to th°
deletion of the atomic absorption (AA)
direct aspiration methods for cadmium
and chromium from the list cf methods.
The Agency deleted these methods from
the list because they do not provide
adequate sensitivity to meet the specific
performance requirements for these
anelytes. In addition, the evaluation of
data when using the method for these
analytes, 33 demonstrated by the review
of the most recent available WS PE
mudies #020-025. revealed high data
variability.
d. Method Detection Limits and
Practical Quantitation Level. EPA
determines practical quant • ation levels
(PQLs) for each substance for the
purpose of integrating analytical
chemistry data into regulation
development. This becomes particularly
important where MCLGs are zero or
some other very low number, near or
below the detection limit. The PQL
yields a limit and specific precision and
accuracy requirement which EPA uses
to develop monitoring requirements. As
such. PQLs are a regulatory device
rather than a standard that labs must
specifically demonstrate. The following
is a discussion of how EPA used PQLs to
set the standards in this rule.
(1) inorganics
The PQLs and the acceptance limits
for the inorganic contaminants, except
fcr mtrfte and asbestos, were
determined using WS PE studies ^012-
017 as detailed in the proposal and
summarized in table 8. One commenter
suggested that currant WS PE studies
should be included in die assessment of
the analytical acceptance limits and
PQLs for the inorganic contaminants to
provide an even broader data base
reflective of overall analytical and
laboratory performance capabilities.
The Agency concurs with this and. in
fact, has established the practice of
periodically reviewing and evaluating
the most recent studies, when they
become available, to determine ths
necessary updates for the regulated
contaminants. WS PE studies #020-025,
as applicable, were evaluated and they
verified that laboratories are continuing
to demonstrate the ability to meet the
established acceptance limits and PQL
criteria as documented in table 16, with
the exception of nitrite, which is
addressed below.
(2) Nitrite
The "plus or minus percent of true
value" acceptance limits for expected
performance and the PQL fcr nitrite, as
reported in table 15, were proposed
based on the analytical procedures
being the same as and the method
detection limits similar to nitrate. This
approach was used because data (PE
studies) were not available to asses? the
acceptance limits and PQL for nitrite.
However, EPA has evaluated the most
recent data now curr-.-ntly available
from nitrite analyses WS PE studies
=022-025, and has determined that the
acceptance limits and PQL for nitrite
will be ±15 percent and C.4 ms/1.
respectively, in the final rule (s°s tabis
16).
TABLE 16.—INORGANIC CONTAMINANT AC-
CEPTANCE LIMITS AND PRACTICAL
QUANTITATION LEVELS
Inorganic
contami-
nant
Barium '....
Cadmium ..
ChfOfTM-
um ....._.
Mercury
Nitrate
Nitrite
Selenium...
MCL
(mg/i)
2
0.005
0.1
0.002
10
1
0.05
Acceptance
limits (plus or
minus percent ol
the true value)
15
20
15
30
POLs
(mg/i)
0.15
0.002
0.01
0.0005
1C | 0.4
15 I 0.4
20
0.01
1 MCL is the proposed level.
e. Inorganic Chemical Sample
Preservation. Container, and Holding
Time. EFA is specifying that the
maximum holding time fcr mercury in
the sample collection table be revised to
specify 23 days for glass or plastic
containers. This change will provide
consistency with the recommended
holding time for wastewater (CFR 40
136.6. table II). the source of the
specifications for ths rule (see table 17).
TABLE 17.—INORGANIC CONTAMINANT SAMPLE PRESERVATION. CONTAINER, AND HOLDING TIME REQUIREMENTS
Cofttvranvit
I
Preservative'
Container1
Maximum
AtbeStOS
ftnrhfm , , ,,
Cadmiufn
Ruc-rida
Mercury
Mitral*
Nitra'e'NiWte
Selenium., .. _...._
Coo1 4 *C . . - -
Cone HNOi to pH <2
Cone HNOi to pH <2 , „ . ,., - --,
Cone HNO> to pH <2 f, ,..,.,.--,-—„ -
None ' — — .
Cone HNCs to pH <2 . ...«.« -
Cool 4 "C
Cone MiSCX to pH <2 ,. ... ,,..,....,-TT-
Cool 4 !c J „
Cone HNOi to pH <2 _,,„,....,., —
PorG
PorG
PorG
PorG
PorG
PorG
PorG
PorG
PorG
PorG
6 months.
1 month.
28 days.
46 noun.
| 28 day*.
48 hours.
' 6 months.
1
1 I) HNCs cannot be used because ol sNpoing restrictions, sample msy be initially preserved by icing and immediately shipping it to the laboratory. Upon receipt
In th9 laboratory, the sample must be aoxJHied with cone HNO, to pH <2, At tame of analyse sample container should be Owoog.Dy rinsed with 1:1 HNO»; washings
should be aoded to Mmpte.
'P-plasuc. harder soft G-gtaes. hard or soft '
* In all cases, samples should be analyzed as soon after coUeeoon as possible.
3. SOC Analytical Methods
a. VOC Methods. Most commenters
supported the analytical methods as
proposed. However, several changes
and clarifications of the proposal are
made in this notice. Four commenters
felt Methods 502.2 and 524.2 should not
be implemented at this time. The
commenters felt it would be difficult to
implement the use of capillary column
and that input should have been
obtained from the laboratory community
that the methods were not technically
available for routine use. Three of the
commenters felt there was a problem in
meeting the quality control (QC)
requirements in the methods.
particularly for Method 524.2. One of the
commenters reported difficulty with
water desorbing from the trap (which is
used in the purge and trap devices to
retain VOCs for analysis). One
commenter felt regulating cis- and trens-
1.2-dichloroethylene separately forces
the use of Method 524.2 to achieve
resolution, but permits co-elution of
other VOCs. The commenter felt this
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3550
Rsgiste / Vol. 56. No. 20 / Wednesday, January 30, 1991 / Rules and Regulations
situation would necessitate the use of a
capillary column.
Methods 502.2 and 524.2 were
developed as a result of public
comment. EPA proposed MCLs for eight
VOCs on November 13.1985 (50 FR
46302). Commenters recommended the
use of capillary column techniques, and
EPA agreed and developed methods
502.2 and 524.2. These were proposed in
the April 17.1987 notice (52 FR 12879)
and finalized in the July 8,1987 notice
(52 FR 25702).
Water desorption from the trap is a
problem common to all purge and trap
methods in EFA's 500, 600. and 8000
scries. The problem is particularly acute
in the gas chromatograph/mass
spectrometry (GC/MS) methods, but can
be minimized by tollowing the trap
bake-out procedures in i 11.4 in both
Methods 502.2 and 524.2.
When monitoring a large number of
unknown compounds with the
possibility of co-eiuting substances, use
cf confirmatory columns is necessary
even for GC/MS techniques. Method
524.2 allows the use of three different
chromatographic columns under four
different sets of operating conditions.
allowing a greater differentiation and
resolution of VOCs than any other 500
series VOC method.
EPA notes the QC requirements in
Method 521.2 are identical to those in
Method 524.1. These requirements were
demonstrated by three different analysts
using three different columns.
Summarized data for WS studies 20-
24 for the regulated and unregulated
VOCs indicate r.on-EPA. non-State
laboratories can successfully utilize
Methods 502.2 and 524.2. Approximately
500 labs now analyze VOCs. The use of
Methods 502.2 and 524.2 has also
increased as a result of WS studies 20-
24. Seventy-five percent of the labs
reporting a method use either Method
502.2 or 521.2. For these reasons. EPA
will continue to approve Methods 502.2
ar,d 524.2.
b. Method Availability. Ten
common ters felt there were too many
methods for the individual pesticides
and that the available methods required
second column confirmation, resulting in
excessive costs. The commenters felt
EPA should wait until suitable GC/MS
methods are available before regulating
these pesticides. EPA assessed the
impact of regulation, if monitoring was
implemented for these pesticides, and
found the costs were not excessive.
estimated at §180 or less per sample.
Furthermore, the vulnerability concept
in this regulation should limit the
number of water supplies that will
monitor any or all of these pesticides.
The commenters further stated that if all
the pesticides were present at the same
time, particularly the multi-peak
residues, chlordane, toxaphene. and
PCB& only GC/MS could distinguish
them.
EPA has in fact found through
numerous national surveys for
pesticides and PCBs, including the
current National Pesticide Survey (NTS)
and other programs like Superfund. that
the pesticides in this rule do not all
occur at the same sites. However, EPA
agrees with the commenters that GC/
MS is the most economical procedure
and indicated in the May 22,1989
proposal that it was investigating GC/
MS methods. Data supplied by
commenters and EPA's Environmental
Monitoring and Systems Laboratory
(EMSL) demonstrate EPA Method 525,
discussed below, which was proposed
for monitoring unregulated
contaminants, can be utilized as a
primary analytical technique for tha
majority of the pesticides. Consequently,
for the reasons cited above. EPA is
promulgating Method 525.
c. Cleanup Procedures. Four
comraentera took issue with the lack of
cleanup procedures for the pesticide
methods. Laboratory methods
addressing contaminants under the
SDWA are for finished drinking water.
Most of the pesticide methods listed
below were derived from the methods
used in the National Pesticide Survey:
cleanup techniques were not included in
most of the methods since experience
has shown even a clean groundwater
sample does not usually need sample
cleanup, which would only add
unnecessary cost.
d. Pesticide Methods. Several
commenters pointed out that Method 504
is the same as Method 505. EPA agrees
that the rr.elhods are similar except for
temperature programming of the gas
chromatograph and that theoretically
Ihe compounds run in Methods 504 and
505 could be run in the same analysis. In
the absence of persuasive data,
however. EPA believes it is better to
isolate the two volatility ranges in
separate analyses.
In an interlaboratory study of Method
505 (U.S. EPA M3thod'Study 40). no
significant differences could be seen in
the recoveries of the analytes in reagent
water and ground water, which ranged
from 90 to 120 percent. Precision as
represented by the relative standard
deviation (%RSD) ranged from 11 to 30
percent for the analytea in reagent water
and from 11 to 40 percent in ground
water. Both the interlaboratory studies
and Water Supply Studies indicated
Method 505 is not recommended to
analyze atrazine.
Several commenters complained
about the use of diazomethane as the
esterifying agent in Method 515.1. While
EPA laboratories have used this reagant I
safely for many years, EPA agrees this is
a matter of concern and is attempting to
resolve this situation. In the interim.
those laboratories that do not wish to
use diazomethane can use the
derivatization procedure in the packed
column methods currently cited in 40
CFR 141.24 (H for 2,4 = D and 2.4,5 = TP.
Pentachlorophenol can be analyzed by
Method 525.
c. Method 525. Eleven commenters
commented about the lack of a GC/MS
method to cut down on the number of
methods, reduce the cost of compliance
monitoring, and provide a positive
identification.
EPA stated in the proposed rule that it
was investigating GC/MS methods for
those analytes that use gas
chromatography. EPA Method 525,
"Determination of Organic Compounds
in Drinking Water by Liquid-Solid
Extraction (LSE) and Capillary Column
Gas Chromatography/Mass
Spectrometry," was proposed as an
analytical technique for monitoring
unregulated contaminants under
§ 141.40. Special Monitoring for
Inorganic and Organic Chemicals. At the
time the nils was proposed, sufficient
data were not available for the
regulated analytes. During public
hearings and in the comment period,
data supporting expanded use of this
method were submitted by three
commenters, including EPA's
Environmental Monitoring and Systems
Laboratory (EMSL], and from WS study
23. An improvement evaluated by EMS1
was the use of C-18 LSE discs as well as
the C-18 LSE cartridges. In using
Method 525. analytes, internal
standards, and surrogates are extracted
from water by passing a liter sample of
water through cartridges or discs coated
with chemically bonded C-18 organic
phase (liquid-solid extraction, LSE). The
sample components are eluted from the
LSE wilh a small quantity of methylene
chloride, which then is evaporated a
volume of to 0.5-1.0 ml. The sample
components are identified and
quantified by using a high resolution
capillary column/GC/MS system. The
pesticides in this rule were run with the
two extraction systems on three types of
mass spectrometer systems—ion trap,
magnetic sector, and quadrupole.
Alachlor, atrazine, chlordane.
heptachlor. heptachlor epoxide. lindane.
methoxychlor. and pentachlorophenol
can be extracted by the use of Method
525. The method specifies an accuracy
range for analytes and surrogates of 70
-------
Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / l\ules and Regulations 3551
o 130 percent and a precision less than
or equal to 30 percent, which the listed
nnaiytss can meet. Use of Method 525
.-.Hows monitoring of regulated and
unregulated compounds simultaneously
and can eliminate five other analytical
methods. Consequently. EPA is
promulgating EPA Method 525 far the
analysis of alachlor, atrazine. chlordane.
heptachlor, heptachlor epoxide, lindar.e,
methoxychlor. and pentachlorophenol.
/. PCB Analytical Methods. In the
proposed rule, EPA stated it had
evaluated existing methods which, for
the most part, are adaptations of
chlorinated pesticide procedures. EPA
explained the difficulty in applying
these procedures to finished drinking
water due to the removal of specific
congeners by the treatment process. In
the propo-ed rule EPA outlined an
approach which would give a
quantitative answer for total PCBs while
minimizing false positives.
Thirty-two cerumen ters expressed
views on PCBs. Sixteen did not like the
current EPA procedure of Methods 505
and 508 to screen, and Method 5C8A for
quantitation. Seven commentcra wanted
EPA to dtvelop a GC/MS procedure
before regulating PCBs. Five
commenters were concerned about false
positives generated by perchlorination
cf biphenyl and related compounds.
Seven commcnters felt the method
detection limits (MDLs) end PQLs were
too low or incorrect; they felt the
regulated community could not meet
them. The rest of the commentcrs cited
problems with availability and cost of
methods, the ur.suitability of Method
505. and the lack of performance
evaluation data.
EPA has evaluated various available
methods, as stated above. None of these
analytical schemes gives a reliable
quantitative answer to environmentally
degraded PCB samples, nor were any
provided by the commenters.
Accordingly, the proposed procedure fcr
PCB analysis is supported by
performance and is made final.
Because of poor participation by the
public sector laboratories, data utilized
from Water Supply (WS) studies 23-25
were from non-EFA. non-State
laboratories. These data showed ihat
these laboratories could screen and
quantitate down to 0.1 .^ig/1 total PCB.
for commonly occurring aroclors euch as
1242 and 1254 using the protocol stated
in the proposed rule. EPA has
determined that these performance data
support the FQL of 0.0005 mg/1 for total
PCBs. The apparent discrepancy in the
MDLs obtained with screening by
Method 5C5 or 508 and quar.titation by
Method 508A indicate that the MDLs tor
Method 508A represent the amount of
the particular aroclor needed to reach
the detection liir.it of
decQchlorobiphenyl, which is 71 percent
chlorine. Typical aroclor designations
1221 or 1260 represent 21 percent and CO
percent average chlorine content,
respectively. Aroclcr 1221 is composed
mostly cf biphenyi, monochloro, and
dichlorobiphenyl congeners with poor
sensitivity to electron-capture detectors,
giving it an MDL of 0.02 mg/1.
Conversion tT the detection level of
decachlorobiphenvl takes only a
fraction of this amount. Conversely 1260.
as expected, shows little increase in
sensitivity as decechlorobiphenyl.
EPA evaluated the problem of false
positives with Method 508A. In the
proposed rule, EPA required screening
usins Methods 505 or 508 to ensure PCBs
were actually present. EPA explained
that these methods are not used for
actual quantitation because high
resolution capillary chromatographic
columns used in Methods 505, 508, and
50BA can co-elute compounds such as
chlordane. thus adding to the apparent
concentration of PCDs. Method 508A. by
converting ell the PCDs to decachloro-
biphenyl, separates this total PCB from
potential co-elutants due to its longer
retention time in the gas chromatograph.
This improved specificity adequately
compensates fcr potential
perchlorination of biphenyl or related
compounds.
Interlaboratory studies now available
for Method 505 and WS data indicate
Method 505 is suitable as a screening
method for PCBs. WS studies indicate
about half the non=EPA. non-State
laboratories use Method 505 as a
screening method. EPA has locked at
the MDL for GC/MS methods, including
Method 5C5. and, at this time, no GC/MS
technique will meet its requirements.
EPA feels the cost of the analysis is
reasonable since the PCB screen is done
as part of the chlorinated pesticide
analysis.
g. VOC Performance Studies. A
number of commenters stated that thev
were una'oie to meet the ±20 percent/40
percent prricrmance requirements for
VOCs first established July 8,1987.
Updated WS studies 20-24 indicate that
EPA's decision to establish acceptance
limits for VOCs at ±40 percent of the
true value for concentrations less than
10 fig/1 and ±20 percent at
r.oncentrations 10 ftg/1 or above was
correct. The results of these studies are
in the docket for this rule.
EPA originally expected the
percentage of private commercial
laboratories able to meet the specified
performance limits to be much lower.
Summarized data for regulated and
unregulated VOCs from WS20-24
indicate improvement to the point that
there is no significant difference in
performance between the public and
private laboratories for t-.ast VOCs.
Private commercial laboratories show
continuing improvement as they gain
experience using the analytical
methodology.
Four commenters questioned the PQLs
established for VCCs in Phase II. They
felt the original PQLs cf 0.005 mg/'l (5
fig/1) based upon MDLs of 0.2-0.5 fig/1
reported by seven EPA and EPA
contract laboratories were erroneous.
The commenters felt these stringent
PQLs resulted in MCLs for three
carcinogens—1.2-dichloropropane.
otyrene, end tetrachloroeihylene—that
many laboratories would net be able to
accurately measure.
EPA revised its VOC methods in
December 1988 with new MDLs. WS
data (WS20-24) indicate 60 to 75 percent
of reporting laboratories now use the
capillary column Methods 502.2 and
524.2. These methods have MDLs
ranging from 0.01 to 0.05 fig/1 for the
VOCs in this regulation. The WS data
for WS studies show the laboratories
have been challenged with at leest one
sample at or below the 0.005 mg/1 PQL.
The performance data indicate that the
use of the 0.005 mg/1 PQL establishes a
level for adequate performance for non-
EPA, non-State laboratories.
h. Pesticide/PCB PQL and
Performance Acceptance Limits. In the
May proposal. EPA estimated pesticide/
PCB PQLs based on 10 times the
minimum detection limits (five times for
EDB and toxaphene). EPA stated that
ongoing performance evaluation studies
would determine whether the estimated
PQLs are achievable. Performance data
now available from WS studies 22-24
(23-25 for PCBs) for the non-EPA. non-
State laboratories show this approach
was justified. WS studies 22-25 bad
values bracketing the PQL/MCL for
most pesticides. In some cases, the WS
data indicated the PQL could bo
lowered from the levels proposed in
May 1989.
Fifteen commenters responded to
EPA's procedures for setting MDLs and
PQLs. Most of these commenters took
issue with EPA estimating the PQLs at
five times the Interlaboratory Method
Detection Limit (IMDL) for EDB and
toxaphene. Six commenters complained
about using the single laboratory MDL
to set the PQL for PCBs. Two of'ths
commenters had the same complaint
about atrazine. Several commenters
stated that precision and accuracy are
sacrificed to attain a lower level of
detection.
-------
3552
Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
Performance data now available from
WS studies 22-25 indicate non-EPA.
non-State laboratories car. screen
pesticides for PCBs at 0.1 jig/1. The
interiaboratory performance data
support the PCB PQL of 0.5 ng/1- Data
for atrazine from WS studies 22-24 and
from EPA Method Study =40 using
Method 507 support a PQL of 0.001 mg/1,
as proposed.
Several commenters cited the large
gap between some of the proposed PQLs
end the MCLs. EFA agrees, and in the
case of Silvex, 2,4-D, and methoxychlor.
has raised the PQL. Raising the PQL
snouid result in increased precision and
accuracy for most laboratories. Because
Cr-.e MCLs for Silvex, 2,4-D. and
rr.ethoxychlor are set at a level equal to
the MCLG, raising the PQL has no effect
on the MCL or the health basis of the
standard. In the case of toxaphene.
performance data indicated the PQL
should be lowered from 0.005 mg/l to
0.003 mg/1.
Data showed that the PQLs for
aldicarb and aidicarb sulfoxidc could be
lowered from 0.005 and 0.008.
respectively, to 0.003 mg/1. Likewise.
watar supply data showed that the PQL
for pentachlorophenol should be raised
from 0.0001 mg/1, as proposed, to 0.001
mg/1. The PQLs for aidicarb. aidicarb
sulfoxide. aidicarb siilfone, and
pentachlorophenol are reproposed
elsewhere in today's Federal Register
for additional comment.
Acceptance limits have been
calculated from WS studies 22-25 using
regression equations derived from the
data. The acceptance limits were
calculated at a 95 percent confidence
interval at the MCLG or at the MCL if
the MCLG was zero. The raw water
supply data were plotted both at the
acceptance limits and as a percentage
around the true value to find a point at
which 75 percent of the laboratories
passed. Most of the limits were
calculated frcm non-EPA, non-State
data due to poor participation of the
public sector laboratories. Table 18 lists
the acceptance limits for the 18
pesticides/PCBs in this rule.
TABLE 18.—PESTICIDE/PCB PRACTICAL CJANTITATION LEVELS AND ACCEPTANCE LIMITS
Contammam
i
| Final MCL
t
I Acceptance i
limits j
(percent! i
Final POL
(mg/l)
: Proposed
\ FQL
C3CP
ETP9
A;achlor
Atrazine .
Carbofuran .
O.lordane
Meptacnlor
Heptachlor epoxide
Undane . . . .
Metftoxycnlor . .
PCBs (as Decacnlorcbiphenyl)
Toxaphene . .
Aldicart) '
Aidicarb sulfoxKJe * , .
Aidicarb sulfone '
PontacWorophenol '
2,4-D
2.-J.5-TP
0.0002
000005
0002
G.003
0.04
0.002
O.OOC4
0.0002
G.0002
0.04
0.0005
0.003
O.C01
0.001
0.002
0.0001
0.07
0.05
-•-40
--40
-45
--45
--45
— 45
-45
-45
-45
-45
0-200
-•-45
-•-55
-55
*55
*50
-50
-50
0.0002
000005
0002
0.001
0.007
0.002
0.0004
0.0002
0.0002
0.01
0.0005
0.003
0.003
0.003
0.003
0.001
0.005
O.C05
0.0002
0.00005
0.002
0.001
0.007
0.002
0.0004
00002
0.0002
0.001
0.0005
0.005
0.005
0.008
0.003
0.0001
0.001
0.0002
' MCL is the proposed level.
4. Selection of Best Available
Technology
a. Inorganics. To fulfill the
rsquirements of Section 1412(b)(6),
regarding the selection of treatment
techniques that the Administrator finds
to be feasible for meeting each MCL.
EPA proposed best available
technologies (BATs) for each of tne
inorganic contaminants, as summarized
in Table 16 of the Federal Register
Notice of May 22.1389. DATs were
selected on the basis of documented
efficiency in removal of each
contaminant, commercial availability of
the technologies, compatibility with
cuher water treatment processes, and
feasibility. Among the BATs proposed
were conventional processes, such as
lime softening and coagulation/
filtration, and less commonly applied
technologies such as activated alumina
and reverse osmosis. All BATs for each
inorganic contaminant were discussed
in the May 22,1989 proposal, and
extensive review of performance
information and lab, pilot, and full-scale
data are contained in EPA Technologies
and Costs (T & C) documents for each
inorganic covered by the proposal.
These documents were referenced in the
proposal and are part of the official EPA
docket for this regulation. Table 6
summarizes the BAT for the inorganics
for today's rule. As discussed below, the
BATs (except electrodialysis) are
identical to those proposed in May 19S9.
One commenter supplied information
regarding electrodialysis reversal (EDR),
a membrane technology, and asserted
that the information supplied to EPA
confirms the use of EDR as BAT for all
but asbestos of the inorganic
contaminants addressed in the proposal
of May 22.1989. The information, much
of which had previously been submitted
to EPA and reviewed by EPA staff.
consisted of consulting engineering
studies, product literature from the
company that markets the technology,
correspondence records, historical
information regarding applications of
electrodialysis for drinking water and
industrial wastewater treatment,
technology and cost information, and
general discussions regarding the
capabilities of EDR and other
technologies in the treatment of brackish
waters.
The commenter sought a detailed
response from EPA regarding EDR.
formally requesting that EPA address
several (a total of six) points whicn
question EPA's rationale for excluding
EDR as a BAT for the seven subject
inorganics in the proposal. The
commenter requested EPA
documentation regarding its response >
previous electrodialysis related
correspondence, and also requested
EPA's explanation regarding any
exclusions of EDR as BAT in the final
regulation. The EPA Comment/
Response document contains the
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Federal Register / Vol. 56, No. 20 / Wednesday. January 30, 1991 / Rules and Regulations 3553
detailed response of EPA to each of the
conmenter's concerns.
EPA reviewed the comments
regarding eiectrodialysis (EDR),
including materials sent by the
commcnter in January 1990 in response
to a request by EPA to provide clear
data to support some of the commenter's
claims. Field tests and full-scale
operating data from electrodielysis
plants treating public water supplies
confirm that EDR is capable of
efficiently removing barium (88 percent
on average), nitrate (51 percent to 92
percent), end selenium (71 percent
removal). The EDR data, most of which
were collected during a study by New
Mexico State University, demonstrate
that EDR technology is appropriate and
feasible.-end that it is capable of
efficiently reducing source water
barium, nitrate, and selenium, as veil as
other frequently occurring salts found in
moderately brackish waters. Based upon
the data submitted to the Agency by the
commenter, EPA has concluded that
EDR is a BAT for removal of barium.
nitrate, and selenium.
In regard to the four other inorganic
contaminants that are subject to this
regulation (i.e.. cadmium, chromium.
mercury, end nitrite). EPA found that the
available data could not support a
conclusion regarding EDR as a BAT.
Many of the claims made by the
commenter were not referenced or
supported by actual data. EDR removal
efficiencies cited within the comments
were generally lower than efficiencies of
proposed BATs. Therefore EDR was
found not to be equivalent to the
proposed BATs in removal of the four
other inorganics. Table IS illustrates the
difference between the efficiencies of
removal obtained by applying the
proposed BATs and those achieved by
EDR.
TABLE 19.—ELECTRODIALYSIS PERFORMANCE COMPARED TO PROPOSED BATs
! Propcsod BAT removal efficiencies
Banum
Cadmium
Cnrofmu.T,
Morcury
Nitrate _ .
Nitnic
Selenium ._ _.
I
_ _ . | 90-98 percent
I 82-93 po*cen*
Electrotiuilysis removal etixaencie:
58-9-1 percent '.
70-75 percent ' _
88-01 oarcant *. .. ..
I 40-100 percan* I Quip ifwmetufuva . .
I 67-83 percen; _ _ _
I 67-99 percent
I 75—99 percent
51-92 percent '
70 percent 2
71 porcent ' _
| BAT
1 Yes.
| NO.
| No.
| No.
| ves.
. .. I No
| Yes.
1 Rate from dnnkmg water pilot study.
* Dais rrom inauRnai wcttewaler applicztioris at etecti-odialy&s technjlocy
In addition to the low EDR efficiencies
evident in the ccmmenter-supplied
reports, many of ths data are
inappropriate because they were
collected at sites employing EDR to
separate and/or recover industrial
wastewater contaminants. Operating
conditions at plants treating drinking
water would cleajiy be different than at
plants treating industrial wastes. To
determine efficacy of trenur.ent, EPA
relics on ciuali.y data obtained under
verifiable concLuor.s which would be
replicated under typical drinking water
treatment conditions.
EPA would welcome reports, data,
and any additional test results on the
EDR process aopiied to drinking water
co mat in the furure the Agency may be
able to determine t::e status of this
technology as a potential BAT for
removal of any contaminant to be
rcjrulatcd under the SDWA.
Because EDR is a newly recognized
BAT for bsri'-in. nitrate, and selenium,
EPA feels that it is appronriate to
describe some aspects of the EDP.
process and address treatment costs
associated with EDR application to
drinking water. Eiectrodiaiysis is c
membrane process tnat separates
ionized cr cnargsd jar.iomc and
cationic) substances in feed wacer by
allowing ions to pass through transfer
membranes. The membranes are
configured in "stacks," parallel to one
another, and each successive membrane
carries a direct electric current which is
either positive (cathode) or negative
(anode), in alternate fashion. Cations
migrate through the cathode membrane
end anions migrate through the anode
membrane, yielding partially deionized
water and concentrated v.astewater in
alternating stacks which flow cut of the
unit, or are recycled or recirculated
tiirough additional treatment stages to
reach the desired product.
A modification and improvement to
the eiectrouiaiysis process is the
automatic reversal of soiarity, from
positive to negative, of direct current
across each membrane at regular 15 to
30 minuia intervals. Automatic polarity
reversal causes ion movement to
reverse, switching product end
concentrate streams. By this process.
fouiants end scale tend to slough off of
membranes end are purged along with
the waste stream. This self-cleanir.?
mechanism appears to extend
membrane life to 5 to 10 years. Another
advantage of EDR over other membrane
processes is EDP. s opparent ability to
achieve greater product recovery (up to
95 percent), thus producing c smaiisr
water stream to dispose (Zelver. 1963:
Zeiver 19COJ. Others have reported on
pilot-scale performance and cos;: of EDP.
compared to reverse osmosis fRO) and
demonstrated the near equivalencs of
these two processes in terms of
feasibility and projected coot fF.obinson
et a!.. 198G: Boy'c Engineering, 1989).
All available information was
reviewed in regard to conformity of EDP.
with other SOW A BAT requirements.
Compatibility of EDR w:th other
technologies, feasibility, ability to
achieve compliance at a reasonable ccs!
and coramerciui evail^b/uiy of EDR are
equivalent to FQ, another BAT for many
inorganics, ui SMSUQ.-.. eic;u'oJ:aiysis
has a his!orv o! pe:tormaj:( e in :l.-e
water SUP::;;, and industrial was:o
treztmar.' '--ids (aoout 2a year:-). As
with HO, JLiJr. is no;-e L^no.'uicxl-y
applied v.-hc-e taw waiu is moderately
brackish, i.::.. WO 10 2.000 tpro dissolved
solids. \vhJd; >3 fau;y ccirunon in the
southern, cx.iirt;. and western united
States.
Cost artaJ-.'srs provided bv ihe
comments' ?nd moss pub-isnrd by
others (OIA. 1930 fAVVVWv. 1989; Euro;
1989: Dyk?>; ::r.r\ Ccrjw.'i. 193i; Conion
end McCitl<:i::, l=j\i indicate tin? cost
feasibility t;i' sn-.-yirs EDR e~:l HO i'cr
gcnersi aer,c.;:vr.R ar.d for retrova! of
specific cor.iiiir.ir.cTi'.i fro:n wav?~
supplies. Production coses ero in the
ranee of .71.0-0 to S2.50 per :.CIO gallons,
includiiie en:or:i:?d capr.ni e'.;i
operations and r,:2:r.rc;i.?nce. for 1 to 1C
MGD plant.' Waste disposu'' \ia derp
v;c!l injecti:-n would f;s i:i !?>•? ranpe nf
!L0.20 to JC.CJ per l.OOJ gsi-crs.
EPA estimated eiscnod>aiysis was*.-;
trectment/disnosai costs in the
September 1980 waste TftC documents
(EPA. 1S86). Waste disposal options and
-------
.1554 Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
resign and cost criteria for EDR were
assumed to be equivalent to those for
RO. leading to identical cost curves.
EDR and RO water treatment costs
could also be assumed to be equivalent:
CDR capital costs tend to be lower than
KO, but the consumption of electrical
power to run an EDR plant offsets the
total production costs to the point of
nearly equalizing the overall cost of
applying the two technologies.
there should be no substantial
changes to the final regulatory impact
analysis (RIA) as a result of a new BAT
(i.e., EDR) in the final rule because (1)
water production and waste treatment
costs for RO and EDR are nearly
equivalent and (2) a relatively small
percentage, about 5 percent, of systems
estimated by the RIA would use RO to
comply with an MCL.
Other technology related issues were
raised in response to the proposal. Each
comment is fully addressed by EPA in
:hs Comment/Response document:
however, a brief overview of comments
and EPA responses is provided below.
One commenter noted the "limited
capability" or effectiveness of lime
soitening in removing selenium, and of
ion exchange (IE) and RO in removing
nitrates from water. EPA refers to the T
& C documents (one for each of the
inorganic contaminants, as cited in the
proposal) which bring together all
treatment data available at the time of
document preparation, and which to a
great extent form the basis of EPA's
BAT determinations in regard to
trerit.T'.ent efficiency.
One commenter questioned the
practicality of RO and IE technologies
due to the wastes generated and the
attending difficulties related to waste
disposal. A? referenced in the above
LPA response reearding EDR as a BAT.
EPA and others have studied and
documented the costs related to the
iieatrr.eut and disposal of water
treatment waste by-products. The same
referenced litersturt. discusses waste
dispcsa! options and the site-specific
ndiure of available options. In EPA's
view, RO and IE are clearly practical
'technologies and, in some cases, the
technologies of choice due to their
ability to soften, desalt, or otherwise
dcmineralize water intended for potable
srppiy. The historical usage of RO
rr.smbranes to treat municipal water
supplies in Florida, and the application
of ion exchange resins to soften water in
the Midwest, are rather substantial
arguments that th?se technologies are
not impractical. Waste management is.
however, a concern and is recognized as
en integral part of water treatment
which will take a significant portion of
the resources available in the planning
and management of public water
systems (HWSsl.
Three commenters suggested that
pretrsatment costs should be factored
ir.to.EPA's cost estimates, because
pretrsatment could double the cost of
treating water at very small PWSs. One
of the comments specifically addressed
potential problems in removing nitrate
from surface water supplies. EPA
responds that adding pretreatment costs
would be unnecessary in most cases
because existing supplies would
presumably already have been treating
water contaminated with high levels of
turbidity, sulfate. iron, or other fouling,
or competing agents that would impede
RO and IE efficiencies. EPA generally
assesses technologies under relatively
clean source water conditions to
determine BATs. However. EPA agrees
with the commenter's assessment of
pretreatment costs; with pretreatment
added, very small installations would
cost approximately twice as much as
with the IE or RO alone. Medium-sized
systems would cost approximately 30
percent more with pretreatment added
onto the IE or RO treatment.
The issue of compliance cost for each
DAT for :he inorganics received
additional scrutiny by EPA. In
September 1989. EPA revised flow
assumptions to calculate all inorganic
technology costs ("Analysis of Flow
Data." Michael D. Cammings, EPA-
CDVV/TSD. October 1987).
Oased on a re-analysis of the original
flow modcis for systems in the smallest
flow category, EPA now estimates these
systems would on the average be
designed to deliver 24,000 gallons per
day bi;t would only be required to
provide 5.GOO gallons per day. The net
effect of these changes is to greatly
ircrease the cost to remove each
inorganic contaminant per gallon of
water delivered.
For example, the removal of chromium
using two-bed ion exchange treatment in
a Vd'.er system serving 25-100 people
was estimntsd in the May 2?., 198-J
proposal (FR 22108) as $3.40/1.000
gallons. As a result of updating the flow
assumptions, the cost of water treatment
and -A-Kste disposal for chromium is now
estimc:ed at SlO.lG/l.QOO gallons.
Consequently, with the changes noted
above (i.e.. legarding electrodialysis
reversal), the BATs are promulgated as
proposed.
b. Synthetic Organic Contaminants. In
the 1938 i-DWA amendments, Congress
specified in section 1412(b)(5) that
"Granular activated carbon is feasible
for the control of synthetic organic
chemicals, and any technology,
treatment technique, or other means
found to be the best available for the
control of synthetic organic chemicals
must be at least as effective in
controlling synthetic organic chemicals
as granular activated carbon."
The following discussion addresses
the major concerns expressed in the
public comment period regarding the
proposed rile published May 22,1989.
Table 7 lists the BATs for the SOCs. As
discussed below, the BAT for each SOC
in today's rule is unchanged from the
May 1389 propcsal.
(1) Why PTA Is BAT for Air Stripping
Several types of aeration technology
are useful for stripping volatiles from
water. Packed columns or towers have
been more widely studied and used to
reduce the compounds at the levels that
occur in drinking water. Diffused
aeration has been shown to effect
removal of certain SOCs and may have
some advantages under hydraulic or
space constraints. Other aeration
methods such as slat tray, spray, and
airlift pumping have shown good
removals in certain applications for
volatile organics. In all cases, results
vary depending on physical, chemical,
and design factors. Packed column
aeration appears to be the most efficient
method in terms of gas transfer, and
may also lend itself better to emissions
controls than would other aeration
methods. EPA considers PTA the best of
the aeration treatments, thus its
designation as BAT. A utility is free to
choose any method, however. BAT or
other, to reduce a contaminant to the
MCL as long as it performs adequately.
(2) PTA and Air Emissions
EPA received five comments
expressing concern that emissions from
PTA facilities were simply transferring
the chemical and the risk from the water
to the air. In the preamble to the
proposed rule. EPA addressed this
concern for two carcinogenic
compounds—EDB and DBCP. Ey
modeling the risks to populations
downwind from a packed tower
aeration facility, "it was apparent in the
cases examined that the risk resulting
from exposure to EDB or DBCP by
inhalation is several orders of
magnitude lower than that resulting
from drinking the contaminated water.
and that the amount of EDB or DBCP
added to the air did not significantly
increase risks from airborne
contaminants." The maximum
individual lifetime risks ranged from
10" a to 10" ° for inhalation and 10" * to
10~°for drinking the same level. There
was at least three orders of magnitude
difference for any scenario examined
comparing ingestion to inhalation, as
-------
Federal **&**** J Vol. 50. No. 20 / Wednesday, January 30, 1991 / Rules rod Regulations 3535
depicted in table 26 of the May 22,1889
proposal.
However, since several States
regulate emissions from PTA facilities,
EPA is providing a table of costs for
emission controls on PTA units by tha
use of vapor phase carbon. Table 20
presents the costs for different
compounds based upon a matrix of
combinations for ease of stripping and
the adsorbabiiity cf the compound.
Thase costs are in addition to the cost cf
the packed tower stripping itself.
TABLE 20.—ADDITIONAL COSTS FOS
VAPOR PHASE CARPON EMISSION CON-
TROLS FOR PACKED TOWER AERATION
FACILITY
Additional cost ovor PTA
treatment cents/1.0GQ
gallons
Good SmppatoiWy
us- 1.2-
Dtehloroetriylene '...
trane-1.2-
Dichloroethylene <...
Etfcytoenzene •
Monocfiloroben-
zane*
TetraehkxoBthy-
tane "-_-_.__.
Toluene*
Xytonm *
Average SlrppebiWy
1i-
Dichkvoprcpano ' ..
Styrene'
Difficult Strippatxlity
(200:1):4
EDB '
D9CP1
Small
aystem
270
270
270
270
270
270
270
350
940
840
390
380
Medi-
um
•yatem
JS
15
11
11
11
11
11
22
16
16
29
2S
•ysian
13
13
9
9
S
9
S
18
11
11
22
19
'Poori
atom
ictoat*bilr!y.
* Moderate vapor phase carbon adsorbabiMy.
* Strong vascr ptaw carbon adsorbabiiity.
4 Amvaierotio.
Source: Malcolm Pimie, tnc. Memormndom to Dave
Huber. U.S. EPA. February 26. 1990.
(3) BAT Field Evaluations
EPA received 14 comments that the
SDWA requires field testing, not just
laboratory testing, of die applicability of
a technology to specific compounds
before the technology can be designated
"best available" to achieve the MCL.
The SD WA directs EPA to set the MCL
as close to the MCLG as "feasible." The
SDWA defines "feasible" as "feasible
with the use of the best technology * * *
which the Administrator finds, a her
examination for efficacy under field
conditions and not solely under
laboratory conditions, [is] available
(taking costs into consideration)-"
Section 1412(b)(3)(D). EPA interprets
this provision to require field trials for a
technology, not for the application of
that technology to each individual
contaminanl. Consequently, EPA has
not required full-scale field validation cf
a technology's feasibility for treating a
specific contaminant if its effectiveness
has been demonstrated at bench cr pilot
scale for that compound. The
technology, however, must reasonably
be expected to perform in a simikr
manner under field conditions
regerdless of aberrations due to scale-up
factors.
[4] Ccrbcn Disposal Costs
Four commenters were concerned that
the cost of disposal of spent carbon was
not taken into account in the costing
assumptions for the desicn and O&M for
Q facility. The cost of carbon "disposal"
is essentially the cost of regenerating the
spent carbon (and replacing the 12 to 15
percent lost in the process). For plants
whose daily carbon use is less than
1,000 pounds per day, EPA assumes that
the carbon would be regenerated off-site
by the carbon supplier and that cost is
included in the cost of replacement
carbon. Far plants whose carbon
demand is more than 1.000 pounds per
day. it is generally economical to
regenerate on-site. The cost of the
incinerator used to regenerate the
carbon and its operation and
maintenance costs are part of the
facility capital and O&M costs already
factored into total costs. The revised
model that EPA now uses in developing
costs (Adams and Clark, AWWA, Jan.
1983) factors into total costs the expense
of carbon regeneration and replacement.
When powdered activated carbon
(PAC) is used, it is usually disposed of
with the alum sludge in a sanitary
landfill. Commenters expressed some
concern over the disposal costs should
the carbon prove to be a hazardous
waste. Because this rule does not
consider PAC to be BAT. EPA is not
addressing the issue of PAC costs,
including the costs of disposal.
(5) Powdered Activated Carbon as BAT
Five commenters suggested that PAC
be considered BAT since it can be used
for removal of pesticide contamination
in surface -waters and is the same
substance as GAC. EPA's position is
that the use of PAC may be an
appropriate choice of technology in
certain instances. PAC treatment of
surface water that is only intermittently
contaminated by pesticides or other
SOCs could be both economical, in
combination with an existing filtration
plant, and effective.
While PAC has proven effective in
taste and odor control, its efficacy for
trace SOC removal in drinking water is
variable due to factors such as rarbon
particle size, background organics. and
plant efficiency. If application of PAC
will reduce the contaminant below the
MCL it may be used in iieu of another
less cost effective technology, even if
the latter is BAT.
(6) Empty Bed Contact Time
EPA received one comment suggesting
the 7.5-minute design empty bsd contact
time (EBCT) for GAC plants was shorter
than the times recommended by sever:.!
experts, including EPA's Adams and
Clark (JAWWA, Jan. 1933). EPA has
used the 7.5-minute contact time
because multiplying it by the ratio of
design to average flows results in Et
least a 15-minute contact time for all but
the largest three systems, where 11.9
minutes was ths lowest average. A 15-
minute average contact time strikes a
balance between the lower carbon
usage rates obtainable with longer
contact times and the higher capital
costs necessary to obtain the longer
contact times by increasing contractor
size. Long contact times also increase
the preloading of natural organics which
may actually increase carbon usage
rates somewhat. The model, which was
used to develop costs in the proposal,
considered cost for EBCTs of 7.5 and
12.5 minutes. A 7.5-minute design EBCT
was selected for the proposal as a
reasonable time, based upon peer
review.
However, based on this comment and
the study by Adams and Clark
(JAWWA, 1889), EPA decided to revise
the contact time. The EBCT was revised
to 10 minutes at design flow using the
Adams and Clark model, which provide
a more complete and accurate estimate
of costs. The 10-minute contact time at
design flow resulted in average flows
above 15 minutes for all 12 system sizes.
and three minutes shorter et ths 90
percentile level. Designing a 12-minute
contact time for a 90 percentiie flow rate
for each system size resulted in very
short design contact time for the smaller
sys terns.
GAC costs as presented in Table 21 of
today's rule increased from those
presented in Table 27 of ths proposal as
a result of (1) differences in the cost
equations between the CWC model used
in the proposal and the Adams and
Clark model used in this rule; (2) the
costs for carbon storage labor and water
requirements for on-site carbon
transport were included in the revised
costs; and (3) the design EBCT in the
revised costs was 10 minutes, which
required a larger facility, resulting in
larger capital costs, than did the 7.5-
minute EBCT in the proposal. The
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3556 Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
increases ranged from $2 to $6/
household/year (a 25 to 75 percent
increase) for large systems to $300 to
S310/household/year (a 46 to 55 percent
increase) for smaller systsms. It is
significant that differences between
models, rather than the increase in
EBCT, caused most of the cost increase.
In calculations for 0.1 and 0.45 lb/1,000
gai carbon usage rates, the differences
between models resulted in total
production cost increases of 21 to 44
percent for large systems and 38 to 53
percent for small systems. However,
changing the contact time alone from 7.5
to 10 minutes resulted in only a change
of 12 percent for large systems and 5
percent for small systems.
(7) Carbon Usage Rates
Two commenters pointed out that due
to the presence of background organics
the carbon usage rate (CUR) obtained
from distilled water isotherm data is
smaller than that obtained from full-
scale testing with natural water. The
concern was that costs of carbon
replacement and regeneration would be
much higher in actual practice than
those calculated in theory using the
lower CUR. The mass transfer model
EPA used to develop CURs was the
constant pattern homogeneous surface
diffusion model, which uses distilled
water isotherm parameters and kinetic
coefficients determined using literature
correlations.
Section 4 of the T & C document lists
CURs adjusted for background organics
in natural waters by using an
adjustment coefficient derived from a
linear regression of data points. This
adjustment reflects a ratio of field to
model CUR as a function of model CUR.
This coefficient was developed after the
May 22,1989 proposal and improves the
utility of the model. This improved
model is used as the basis for the costs
in today's rule.
EPA is aware that the correlation
between costs and CURs is not as good
for the well-adsorbed compounds such
as the pesticides, typically with low
CURs. Additional field data are needed
in this area. However, costs are very
insensitive to changes in the CURs of
0.5-0.1 lb/1,000 gallons. Most of the
pesticides in question have low CURs.
Adams and Clark (1989) observed that
"there is only a small gradual increase
in cost between a two-year and a six-
month reactivation frequency."
Therefore, even though more data would
be useful, EPA believes that overall
costs for removal of the well-adsorbed
compounds would not be greatly
affected, if at all. Because the prediction
ia only as good as the uniformity of the
water, the effect of the organic matrix
on the carbon wiil change as the matrix
changes in the influent water, despite
accurate scale-ups at specific points in
time. GAC adsorption behavior, and
therefore the CUR, typically varies
among different water matrices with the
same contaminant and operating
conditions. For the well-absorbed
compounds, longer contact times and
higher costs typically result from the
impact on CURs due to the adsorption
sites deeper in the bed being occupied
by natural organics that interfere with
SOC adsorption.
5. Determination of MCLs (Feasibility
and Cost)
EPA proposed MCLs for 36 chemicals
based upon an analysis of several
factors, including:
(1) The effectiveness of BAT in
reducing contaminant levels from
influent concentrations to the MCLG.
(2) The feasibility (including costs) of
applying BAT. EPA considered the
availability of the technology and the
costs of installation and operation for
large systems (serving more than 100,000
people).
(3) The performance of available
analytical methods as reflected in the
PQL for each contaminant. In order to
ensure the precision and accuracy of
analytical measurement of contaminants
at the MCL the MCL is set at a level no
lower than the PQL
After taking into account the above
factors, EPA then considered the risks at
the MCL level for the EPA Group A and
B carcinogens to determine whether
they would be adequately protective of
public health. EPA considers a target
risk range of 10"* to 10"° to be safe and
protective of public health when
calculated by the conservative linear
multistage model. The factors EPA used
in its analysis are summarized in tables
22 and 23 for the Category I and
Category II and III contaminants.
respectively.
a. inorganic Contaminant MCLs. The
MCLs for the inorganic contaminants
promulgated today are at the same level
as those proposed in May 1989 (see
table 1). EPA is reproposing the MCL for
barium due to changes in the MCLG.
The MCL for each inorganic
contaminant is also at the same level as
the promulgated MCLG for each
contaminant. EPA has determined that
each inorganic MCL has one or more
BATs to reduce contaminant levels to
the MCLG, and that the BAT{s) is
feasible (as defined by the Act),
analytical methodologies are available
to ensure accurate and precise
measurement for each MCL. and each
MCL adequately protects public health.
Consequently, the MCLs (except for
barium) are promulgated as proposed.
b. Synthetic Organic Contaminant
MCLs
(1) Category I Contaminants
EPA considered the same factors in
determining the proposed MCLs for
Category I contaminants as for Category
II and III contaminants. However, the
proposed MCLGs for Category I
contaminants are zero, a level that by
definition is not "feasible" because no
analytical method is capable of
determining whether a contaminant
level is zero. The lowest level that can
be reliably measured is the PQL As
described above. EPA calculated PQLs
for the SOCs based on WS studies 20-
25.
In most cases, the PQL is identical to
that proposed in May 1989. In the case
of toxaphene, EPA lowered the PQL
based upon the WS studies. The MCL
for toxaphene is changed from 0.005 to
0.003 zng/1. Results of WS studies 20-25
indicate that the PQL for
pentachlorophenol should be set at 0.001
mg/1 rather than the proposed 0.0001
mg/1 level. Consequently, EPA is
reproposing the MCL for
pentachlorophenol at the revised PQL.
This issue is discussed more fully
elsewhere in today's Federal Register
reproposing the pentachlorophenol
MCL Because the PQL for toxaphene
represents the lowest level feasible. EPA
is promulgating this MCL at a level
equal to the PQL
In the May proposal. EPA estimated
the PQL for EDB as five times the MDL
Results cf WS studies 22-25 confirm that
EDB can reliably be detected at 0.00005
mg/1. Consequently, the MCL is
promulgated as proposed.
EPA also calculated the per capita
costs for large systems to remove the
SOC contaminants to or below the MCL
using GAC or PTA. These costs range
from $10.00 to S44.CO per household per
year. EPA believes these costs are
reasonable and promulgates the MCLs
at the levels listed in Table 22.
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Federal Kegnter / Vol. 56, No. 20 / Wednesday, January 30. 1991 / Rules and Regulations 3557
TABLE 21.—GAG AND PACKED COLUMN COSTS TO REMOVE SOCs
[S/household/year] '
Volatile SOCs:
bs-1 ,2-Dichloroetnylene
Dibromochloropropsne (D3CP)
o-Dichlorooenzena
Ethvtbenzene _
EthyUme dibromide (EDE)
Monocntoroberuene „
Styrene ~ _ _
Tetracnloroethylene _
Tohjeno ...... «. . ......
trarw-1.2-Dichloroethytene _
Kytoner
m-Xvtene _
e-Xytene _. .
p-Xytene ............. _ _
Non-Volatile SOCs:
Alachkx . „ .
Aidtcart) (sutfcnde & sutfone) _
Carbofuran _
2.4-D _ „
Heptachlor
LJndane _ _
Uatty^xy^l^r
PCfif ', . ,.,
pnnt*/>hiMW>h^fytt
Toxaphsns .____.__ . ___...
2,4,5-TP (Sih««) . .... ... ..„.,.„._,..
Carbon
usage rato '
0.39G:
.0446
.1234
9BS7
.1587
.1453
.1930
.0605
.1144
3050
.3793
.2148
.3619
.3716
0371
.1032
.0543
.0570
.0379
.1224
.0556
.0271
.0203
.2137
.027?
0683
.0432
.0813
Smtil >
$950
010
9CO
9"0
620
930
930
910
83D
950
950
930
950
950
910
930
810
910
910
930
910
610
910
BIO
BIO
910
910
B10
GAC
Mad-urn4
$76
36
51
51
51
51
51
36
51
76
76
51
76
76
36
51
29
36
36
51
36
36
36
51
36
36
36
36
Lero«4
S19
10
15
14
14
14
14
10
14
19
19
14
19
19
10
14
10
10
10
14
10
10
10
14
10
10
10
10
Smait4
$140
325
325
190
140
210
150
160
130
150
130
140
140
140
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
tt/A
N/A
PTA
Medium4
$11
60
6"
17
10
23
12
13
S
12
9
10
10
10
Lam?.-
17
41
4;
12
7
16
e
P
6
8
6
f
7
7
Percent
removal *
EO
90
90
83
93
93
90
90
90
9C.7
90
90
90
90
1 Costs ndude amortized capital and annual operation and maintenance.
1 Peccant removals from maximum influent levels to at or below the MCL
• (With background TOO) Table 4-5, Technology and Cost document __ .
4 SrnsJ system* serve 25-100 persons; medium eyslems serve 10,000 to 25.000 persons; large systems serve greater than 1.000.000. Cost in S/housshold/yssr.
Production in cents/1*00 gallons is squat to dollars per household per yew (i.e.. 8 ct/1.000 gallons-S8.00/household per year.
TABLE 22.—MCL ANALYSIS FOR CATEGORY I SOCs
SOC contaminant
AUrMn,
CWortfan^
njluu nmJibmuutfLjiaiuL /nr4(7£»\
1 2-P«f*>lp^W«na
Ethyi«f» dtbrormJ4) (EDB) ,
Heptaehlor tpoxkto ..,._,,....,,..,, . .„,.
rsi lull 1 ilm Ujii isi M il *
Tsirscnavrjwthytana
MCLG1
(mg/l)
0
0
0
0
0
0
0
0
0
0
0
MCL (mg/l)
0.002
.002
.0002
.005
.00005
.0004
.0002
.001
.0005
.005
.003
POL (mg/l)
0.002
.002
.0002
.005
.00005
.0004
.0002
.001
.0005
.005
.003
Annual household costs
using BAT'
GAC
$10.00
10.00
10.00
14.00
14.00
10.00
10.00
10.00
10.00
14.00
10.00
PTA
I—
$41.00
17.00
16.00
8.00
10 -4 risk
level (mg/l)
0.04
.003
.003
.05
0.00004
0.0008
0.0004
0.03
0.0005
0.07
0.003
Notes
MCL 13 1.25 X 10-4
risk.
1 EPA policy Is that tor a!) Category I contaminants the MCLG IS two.
• For large surface systems servmn > 1,000,000 people.
• Proposed MCLG and MCL level EPA intends to promulgate a final MCL by July 1991.
(2) Category U and in Contaminants
For the Category II and UJ
contaminants listed in table 23. each of
the MCLa was proposed equal to its
proposed MCLG. Because MCLGs for
metnoxychlor, styrene. and toluene
changed from the levels proposed in
May 1989. as discussed above, the MCLs
also changed. The MCL for
methoxychlor changed from 0.4 to 0.04
mg/l; styrene changed from O.C05/0.1 to
0.1; and toluene changed from 2 to 1 mg/
1. Each changed MCL is based on o
reassessment of the health data as
discussed above.
Although PQLs for 2.4-D.
methoxychlor. and 2.4 5-TP change from
the levels listed in the May 1989
proposal each is below the MCLs
promulgated today and. consequently.
does not impact these MCLs.
Section 1412 of the SOU™ requires
EPA to set MCLs as clone to the MCLGs
as is feasible (taking costs into
consideration). EPA believes that it is
feasible to set the MCLs at the MCLGs
because (1) the PQL for each
contaminant is at or below the level
established by the MCLG; (2) BAT can
remove each contaminant to a level
equal to or below the MCLG: and (3) the
annual household cost to install DAT in
-------
355® Fader®! Register / Vol. 58, No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
large systems is a maximum of $19.00
per household per year and generally
around or below $10.00 per household
per year. EPA believes that these costs
are affordable for large systems.
TABLE 23.—MCL ANALYSIS FOB CATEGORY II AND III SOCs
SOC contaminant
Aldicart)"
Akftcorb sulfoxide "
Aldicarb sulfone •
Afrnzino
Corbofuran . ...
o-Rchlorobenzena
do-1,2-Dichloroathylena
trans- 1,2-Dichloroetnylena . . .
2.4-O
EUiylbenzene _
Undona.
Mothoxychlor .
Ctonochlorobenzene
Styrena
Toiuano
2.4,5-TP (Sirve*) ....
Xylonas (total)
MCLG
(mg/l)
0.001
.001
.002
.003
.04
.6
.07
.1
.07
.7
.0002
.04
.1
.1
1
.05
10
MCL (mg/
I)
0.003
.003
.003
.003
.04
.6
.07
.1
.07
.7
.0002
.04
.1
.1
1
.05
10
PQL (mg/
I)
0.003
.003
.003
.001
.007
.005
.005
.005
.001
.005
.0002
.001
.005
.005
.005
.005
.005
Annual household
costs using BAT '
GAC
S10.00
14.00
14.00
10.00
10.00
14.00
19.00
19.00
14.00
14.00
10.00
14.00
14.00
10.00
19.00
10.00
19.00
FTA
$4.00
7.00
6.00
7.00
9.00
8.00
6.00
1 For large surface systems serving > 1.000,000 psoplo.
* Proposed MCLG and MCL levels. EPA intends to promulgate final levels by July 1991.
C. Treatment Technique Requirements
The principle sources of acrylamide,
epichlorohydrin, and styrene in drinking
water are impurities in water treatment
chemicals and surfaces in contact with
drinking water.
Because no standardized analytical
methods are available for acrylamide
and epichlorohydrin at low levels in
drinking water, EPA proposed a
treatment technique for acrylamide and
epichlorohydrin and provided guidance
for styrene.
EPA proposed to limit the allowable
monomer levels in products used during
water treatment, storage, and
distribution. These levels are:
Acrylamide: 0.05 precent acrylamide
in polyacrylamide dosed at 1 ppm.
Epichlorohydrin: 0.01 percent residual
epichlorohydrin concentration dosed at
20 ppm.
Styrene: 1 ppm styrene in styrene
copolymers used as direct additives and
as resin. Also, MCLs were proposed at
0.005 mg/l (as Category I) and 0.1 mg/l
(as Category II).
Under the proposed rule, a water
system using a product containing
mcrylamide and epichlorohydrin must
certify to the State that the amount of
residual monomer in the polymer and
the dosage rate would not cause the
concentration in finished water to
exceed the specified level.
Summary of Comments: EPA received
25 comments on the proposal relating to
Obese chemicals. All but six commentero
were generally supportive of the
propose!. Three commentero oupported
tfee approach adopted by EPA. Among
the comments received. 22 were on
acrylamide, 21 on epichlorohydrin and 5
on styrene.
Most conunenters expressed concern
that the language in the proposal does
not clarify who does the testing for
monomer—the water system or the
manufacturer. It was suggested that the
language state that in annual
certification to the States, water systems
can rely on manufacturer's certification.
The commenters overwhelmingly
opposed the idea of water systems
performing the test for residual
monomer.
Today's rule is modified to make it
clear that a water system does not need
to test for monomers. A water system
can either test or rely on manufacturer's
certification or on third-party
certification, whichever mechanism the
State is willing to accept.
Nine commenters suggested that the
issue of monomers in treatment and
distribution aids should be handled
either by the States through a third-
party certification program or through
federal labeling requirements.
Under the SOW A. EPA can establish
and enforce maximum contaminant
levels or treatment requirements but
does not have the authority for
establishing labeling requirements for
proprietary products. As stated above, a
water system can either test the product
or rely on the manufacturer'o
certification or on third-party
certification (e.g.. National Sanitation
Foundation (NSF)), whichever
mechanism the State is willing to accept
One commenter suggested
establishment of MCLs for these
chemicals. Since no analytical methods
(EPA-approved or otherwise) are
available for analysis of low levels of
acrylamide and epichlorohydrin in
drinking water, however, establishment
and enforcement of an MCL would be
impractical. Therefore, EPA has
proposed a treatment-related
requirement rather than an MCL.
Furthermore, EPA feels that the
proposed treatment-related approach is
a valuable preventive measure for
drinking water contamination.
One commenter felt that there is no
factual or procedural basis for regulating
styrene. This commenter offered two
supporting reasons: (1) Two
manufacturers looked for styrene in ion
exchange resins but did not find any
(sensitivity of the method: 1 ppb); and
(2) styrene containing polymers and co-
polymers are subject to the third-party
certification program which should be
able to ensure safety.
According to the information
available to EPA, styrene is present at
low levels in styrene copolymers
intended for use in water treatment as a
secondary direct additive. This,
combined with the fact that styrene is in
wide industrial use and has been found
in 22 hazardous waste sites listed on the
National Priority List, indicates that it
can be anticipated to occur in drinking
water. National Organics
Reconnaissance Survey (NORS)
detected styrene in the water of three of
eight cities monitored.
-------
Federal Register / Vol. 58, No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3559
One commenter believed
epichlorobydrin should not be allowed
in flocculating agents for drinking water
as it is a powerful contact mutagen.
With the proposed treatment
requirement, nominal epichJorohydrin
concentration in drinking weter would
be 0.0022 rog/1. The upper bound
lifetime cancer risk ct this concentration
is calculated to be 6 x 10"'. This is an
extremely low risk considering that the
use of cpichlorohycrin polymers end co-
polymers is widespread arid highly
desirable because these materials are
effective in removing other drinking
water contaminants.
Consequently, with the modification
cs noted above, the treatment technique
requirements for acryianiide and
epichlorohydrin are promulgated as
proposed. The guidance for styrene is
finalized as proposed.
D. Compliance Monitoring
Requirements
1. Introduction
The proposed compliance monitoring
requirements (54 FR 22002) included
specific monitoring requirements for
inorganic contaminants (barium,
chromium, cadmium, mercury, and
selenium): nitrate/nitrite; asbestos;
volatile organic contaminants (VOCs);
and pesticides/PCBs. EPA did not
propose compliance monitoring
requirements for acrylamide and
epichlorohydrin because adequate
analytical methods did not exist for
these contaminants at low levels in
drinking water.
EPA proposed that all community and
non-transient water systems comply
with the monitoring requirements for all
contaminants (except acrylamide and
epichlorohydrin) because of long-term
chronic exposure of these system's
consumers. Transient non-community
water systems were required to comply
with the requirements for nitrate/nitrite
only because of the acute nature of
exposure of these chemicals. The
compliance monitoring requirements
that EPA is promulgating today are the
minimum necessary to determine
whether a public water supply delivers
drinking water that meets the MCLs.
Though MCLCs and MCLs are being
reproposed for aldicarb, eldicarb
sulfoxide, aldicarb sulfonc. barium, and
pentachloropher.ol. EPA anticipates
these will be promulgated by July 19C1.
EPA believes that whatever level is
promulgated for aldicarb, aldicarb
sulfoxide, aldicarb sulfone. barium, and
pentachlorophenol would not affect the
monitoring requirements. Consequently.
the requirements promulgated today
also apply to aldicarb. aldicarb
sulfoxide, aldicarb sulfone, barium, and
pentachlorophenol.
The monitoring requirements that are
promulgated today generally follow the
three-tier approach first outlined on
October 5.1983 (48 FR 45502). Nitrate is
the only contaminant promulgated today
that falls in Tier 1. The remaining
contaminants are regulated as Tier II
contaminants, e status that allows
States the discretion to increase or
decrease monitoring based upon
established criteria and site-specific
conditions. Because of the low
occurrence of nitrite at kvels above the
MCL, EPA has placed nitrite in Tier li in
this rule.
In developing the compliance
monitoring requirements for these
contaminants, EPA considered (1) the
likely source of drinking water
contamination, (2) differences between
ground and surface water systems, (3)
how to collect samples that are
representative of consumer exposure. (4)
sample collection and analysis costs, (5)
the use of historical monitoring data to
identify vulnerable systems and
subsequently specify monitoring
requirements for vulnerable systems, (6)
the limited occurrence of some
contaminants, and (7) the need for
States to tailor monitoring requirements
to system- and area-specific conditions.
Although base monitoring
requirements for surface and
groundwater systems are the same for
all contaminants (except inorganic and
nitrate/nitrite), groundwater systems
will qualify more frequently for reduced
monitoring and return more quickly to
the base monitoring requirements
because (1) the sources and mechanisms
of contamination for ground and surface
water systems are different. (2) the
overall quality of surface waters tends
to change more rapidly with time than
does the quality of ground waters, and
(3) seasonal variations tend to affect
surface waters more than ground
waters. Spatial variations are more
important in ground waters than in
surface waters since groundwater
contamination can be a localized
problem confined to one or several wells
within a system. Therefore, monitoring
frequency is an important factor to
determine baseline conditions fcr
surface water systems, while sampling
location within the system generally is
more important for ground water
systems. Today's monitoring
requirements generally require surface
water systems to monitor at an
increased frequency for longer periods
than groundwater systems.
EPA monitoring requirements arc
designed to ensure that compliance with
the MCLs is met and to efficiently utilize
State and utility resources. EPA s goal in
today's rule is to ensure these
monitoring requirements are consistent
with monitoring requirements
promulgated previously by EPA and
with known occurrence trends. The
monitoring requirements promulgated
today focus monitoring in individual
public water systems on the
contaminants that are likely to occur, an
approach that includes:
• Allowing States to reduce
monitoring frequencies baaed upon
system vulnerability assessments for the
SOCs (VOCo and pesticides/PCBs)
listed in § 141.61(a) and jc) and for
asbestos.
• Allowing States to target monitoring
to those systems that are vulnerable to a
particular contaminant.
• Allowing the use of recent
monitoring data in lieu of new data if
the system has conducted a monitoring
program generally consistent with
today's requirements and using reliable
analytical methods.
• Encouraging the States to use
historical monitoring data meeting
specified quality requirements and other
available records to make decisions
regarding a system's vulnerability.
• Requiring all systems to conduct
repeat monitoring unless they
demonstrate through an assessment cr
other data that they are not vulnerable.
• Designating sampling locations and
frequencies that permit simultaneous
monitoring for all regulated source-
related contaminants, whenever
possible.
• Elsewhere today in the Federal
Register EPA is proposing changes to
the monitoring frequencies that were
promulgated July 8.1907 for eight VOCs.
This change, when final, will require all
VOC sample collection for the 10 VOCs
in this rule and the eight VOCs in the
July 8,1987 rule to occur at the same
time.
2. Effective Date
In the May 22.1989 Federal Register
Notice, EPA proposed to promulgate the
monitoring requirements under section
1445 within 30 days of promulgation
because section 1445 imposes no
limitations on when monitoring
requirements would be effective. After
IB months, the compliance monitoring
requirements would be effective under
section 1412. The MCLs and other
requirements would continue to be
promulgated under section 1412 and
cftcctive in 18 months.
Most commentera did not support
making the requirements effective
within 30 days citing the confusion
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3560 Fsdorai Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
between "new" and "old" regulatory
requirements. Other commenters cited
the lack of laboratory capacity for new
analytical methods. These commenters
stated that laboratories frequently do
not invest in capital equipment until the
rules are promulgated: consequently, the
13-month lead time before analysis must
be conducted is necessary. Most States
cited their inability to adopt regulations
in less than 18 months and pointed out
that if they did not adopt regulations by
the effective oate. EPA would have
primacy for the "new" rule while the
States would retain primacy for
previous rules. The question of who
retains primacy couid.potentiaiiy
confuse water systems. One commenter
indicated tiiat promulgating monitoring
requirements is beyond the intent of
section 1445. Numerous commenters
cited the impact on State resources to
review vulnerability assessments.
enforcement, reduced monitoring
decisions, etc.. as a rationale for
allowing States sufficient time (i.e., 13
months before the monitoring
requirements are effective).
After reviewing the public comments,
EPA agrees that there is the potential for
confusion in moving forward the
effective date for monitoring. In
addition, the Agency agrees that
implementation problems may occur in
beginning monitoring early.
Consequently, in today's action EPA
will promulgate the compliance
monitoring requirements for regulated
substances under section 1412. All
monitoring requirements will be
effective 18 months after promulgation.
For contaminants that have existing
regulatory requirements (inorganics and
nitrate), the water systems must
continue to comply with the existing
requirements until they are superseded
by the new requirements.
3. Standard Monitoring Framework
EPA received extensive comments
stating that the proposed monitoring
requirements are complex and would
lead to confusion and misunderstanding
among the public, water utilities, and
State personnel. Commenters also cited
the lack of coordination among various
regulations. Many commenters
suggested that EPA simplify, coordinate,
»nd synchronize this regulations with
previous regulations. In response tc
these comments. EPA has developed a
standard monitoring framework to
address the issues of complexity,
coordination of monitoring requirements
among various regulations, and
synchronization of monitoring
schedules. This framework will serve as
a guide for future source-related
monitoring requirements adopted by the
Agency. The framework was developed
based on the proposed requirements, the
options and requests for comments EPA
discussed in the proposal, and the
comments received by EPA.
EPA believes that the framework will
in large measure address the comments
that recommended that reducing
complexity, synchronizing monitoring
schedules, standardizing regulatory
requirements, and giving regulatory
flexibility to States and systems to
manage monitoring programs. EPA
believes these changes have the
potential to reduce costs by combining
monitoring requirements (including
vulnerability assessments) for several
regulations on the same schedule and
promote greater voluntary compliance
by simplified and standardized
monitoring requirements.
This framework will first be used in
today's regulation. EPA intends to apply
this framework to future requirements
for source-related contamination (i.e..
VOCs, inorganics, pesticides, and
radionuciides).
Use of the framework envisions a
cooperative effort between EPA and
States. The monitoring requirements
promulgated today are the minimum
federal requirements necessary to
ascertain systems' compliance with the
MCLfl. In some cases. States will
increase the monitoring frequencies
above the federal minimums to address
site-specific conditions.
For all contaminants contained in
today's rule, minimum (or base)
monitoring requirements may be
increased or decreased by States based
upon prior analytical results and/or the
results of a vulnerability assessment.
The monitoring requirements outlined
today follow to a large extent the
requirements proposed on May 22.1989.
In the May proposal EPA stated as a
goal to efficiently utilize State and utility
resources and be consistent with
monitoring requirements previously
promulgated by EPA. EPA believes that
today's requirements meet that goal.
a. Three-. Six-, and Nine-Year Cycles.
In order to standardize monitoring
cycles in this regulation (and in future
regulations). EPA is establishing nine-
year compliance cycles. Each nine-year
compliance cycle consists of 3 three-
year compliance periods. All compliance
cycles and periods run on a calendar
year basis (i.e.. January 1 to December
31). This regulation establishes the first
nine-year compliance cycle beginning
January 1,1993 and ending December 31,
2001; the second cycle beginning January
1. 2002 and ending December 31.2010;
etc. (see 8 141.2—Definitions). Within
the first nine-year compliance cycle
(1993 to 2001), the first compliance
period begins January 1,1993 and ends
December 31.1995: the second begins
January 1,1996 and ends December 31,
1998: and the third begins January 1.
1999 and ends December 31, 2001. EPA
in this regulation is also requiring that
initial monitoring (defined as the first
full three-year compliance period
beginning 18 months after the
promulgation date of a ruie] must begin
in the first full compliance period after
the effective date. For today's
regulation, the effective date is July 30.
1992. Since the next full three-year
compliance period begins January 1.
1993. the ir.itial monitoring period for
today's regulation occurs in the
compliance period 1993-1995.
b. Base Monitoring Requirements. In
order to standardize the monitoring
requirements, EPA has established base
(or minimum) monitoring frequencies for
all systems at each sampling point.
These base monitoring frequencies
apply to all community and non-
transient water systems. In cases of
detection or non-compliance. EPA has
specified increased monitoring
frequencies from the base. These
increases are explained below. Systems
will also be able to decrease monitoring
frequencies fr :m the base requirements
by obtaining waivers from the State
where a State permits such waivers.
Decreases from base monitoring
requirements through waivers are
discussed in general under the section
on decreased monitoring and in the
discussion of monitoring frequency for
each class of contaminants.
In most cases, these increased or
decreased frequencies in most cases are
similar to the frequencies proposed in
May 1989. Specific changes are
discussed below under each
contaminant group.
Inorganic contaminant base
requirements are the same as
proposed—one sample at each sampling
point every three years for groundwater
systems and annually for surface water
systems. Modification of base
requirements for VOCs is discussed
below in the section on VOC monitoring
frequency.
For asbestos and pesticides, EPA
proposed that monitoring was not
required unless the State determined
that the system was vulnerable based
upon B State-conducted assessment.
States were required to complete a.i
assessments within 18 months of
promulgation. If the State determine
that a system was vulnerable to
pesticides/PCBs. systems were requirea
to monitor on a three- or five-year
schedule depending upon system size
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Federal Register / VoL SB, ;No. 20 / Wednesday. January 3D, IflBl / Rules and iterations 3561
and whether contaminants were
detected. For systems vulnerable to
asbestos contamination, repeat
monitoring frequencies for asbestos of
every three years generally were
required based upon ground/surface
water distinctions and the analytical
result of the initial sample.
The May 1989 notice also included an
alternative monitoring scheme which
would require all CWSs and non-
transient, non-community water systems
(NTWSs) to monitor for asbestos and
pesticides/PCBs at specified (base)
frequencies. Most comment* EPA
received opposed a round of initial
monitoring by all systems. These
commenters cited the lack of occurrence
of pesticides/PCBs in drinking water
and the expense of monitoring,
particularly for asbestos. Several
commenters questioned the availability
of sufficient laboratory capacity.
According to the proposed rule, if
States did not conduct a vulnerability
assessment for any one of the 80,000
water systems within 18 months and
determine system vulnerability, then the
system was deemed to be not vulnerable
and would not be required to monitor.
EPA's evaluation of the comments
revealed that States, in particular,
believed that their ability to conduct all
vulnerability assessments within 18
fcponths would be limited because of
Resource constraints on funds and staff.
Most States that commented died this
resource shortfall as a major
impediment
After reviewing and evaluating the
comments, EPA is adopting the
alternative monitoring approach
discussed in the proposal for asbestos,
pesticides/PCBs, and unregulated
contaminants. EPA is making this
change for several reasons. First EPA
believes requiring all systems to monitor
for pesticides/PCBs and asbestos is
more protective of health because
systems will be required to monitor if a
vulnerability assessment is not
conducted. Second, after reviewing the
comments, EPA believes that the
proposed rule was deficient in not
considering the inability of States to
conduct vulnerability assessments
within 18 months. This change in today's
rule creates an enforceable requirement
Finally. EPA believes the impact of
requiring a system to monitor for a
particular contaminant or not. is the
same under the proposed scheme and
today's requirements—provided a
vulnerability assessment is conducted
and a waiver is granted.
_ EPA has combined the above change
•th the provision that systems may
Benduct the vulnerability assessment
and. at the State's discretion, obtain a
waiver (see waiver discussion below).
EPA has shifted the responsibility to
conduct vulnerability assessments from
States to systems because the
vulnerability assessment is a monitoring
activity that historically has been a
system responsibility. Each individual
system can decide whether to conduct a
vulnerability assessment (rather than
monitor) based on cost previous
monitoring history, and coordination
with other vulnerability type
assessments (i.e., sanitary surveys,
Wellhead Protection Assessments). In
addition, because of States' indicated
resource shortfalls, vulnerability
assessments would not occur in many
States. Though EPA permits systems to
conduct vulnerability assessments,
approval of waivers based on those
vulnerability assessments rests with the
States. EPA believes the changes
outlined above address, in part the
State resource issue and will result in an
enforceable drinking water standard.
In addition. EPA has simplified the
waiver procedures to more fully apply to
situations involving pesticides (see the
discussion of waivers below). The
changes outlined above will allow all
systems to apply for a waiver from the
monitoring requirements where States
provide for such waivers. Based on
limited occurrence data. EPA anticipates
that most systems should be granted a
waiver for most pesticides, asbestos,
and unregulated contaminants. In cases
where a system is not granted a waiver
by the State, it will be required to
monitor at the specified base frequency.
Consequently, for the reasons specified
above, ail systems will be required to
monitor for ail pesticides/PCBs,
asbestos, and unregulated contaminants
with an opportunity for reduced
monitoring based upon an assessment
c. Eight VOCs Regulated July 8.1987.
In order to standardize the monitoring
requirements for all VOCs, the repeat
monitoring frequencies promulgated for
tne eight VOCs Only 6,1987 rule) are
being proposed elsewhere in today's
Federal Register so that the
requirements in today's rule will be
identical for all 18 VOCs. EPA intends to
promulgate a final rule for the eight
VOCs by July. 1991. EPA is proposing
this change so a system that has
completed unregulated VOC monitoring
can monitor for all 18 VOCs using
today's increased or decreased repeat
monitoring criteria beginning in January
1993.
d. Increased Monitoring. Although it
is not possible to standardize
requirements for all contaminants, EPA
in this final rule seeks to standardize the
criteria that require a system to increase
monitoring from the base requirements
and that allow the system to return to
the base requirement In general, today's
rule requires monitoring frequencies to
increase when a contaminant is
measured at a certain concentration.
These concentrations are specified in
federal rules, and vary by class or
toxicity of the contaminant. In today's
rule, these "trigger" concentrations are
set variously at the MCL 50 percent of
the MCL, or the detection limit of the
analytical method used to measure the
contaminant Specifically, the trigger
concentrations are (1) 0.5 mg/1 for
nitrite, 5 mg/1 for nitrate, and 5 mg/1 for
nitrate/nitrite combined (each of which
is 50 percent of the MCL); (2) the MCLs
for asbestos and five other inorganic
contaminants; and (3) the analytical
detection limits for VOCs. PCBs, and
pesticides. The detection limit for each
VOC is 0.0005 mg/1. The PCBs and
pesticides detection limits are given in
Table 24. The rationale for varying the
detection limits for increased monitoring
is addressed in each section for the
contaminant monitoring frequencies
below.
After exceeding the trigger
concentration for each contaminant
systems must immediately increase
monitoring to quarterly (beginning in the
subsequent quarter after detection) to
establish a baseline of analytical results.
Groundwater systems are required to
take a minimnmm of two samples and
surface water systems must take four
samples before the State may permit
less frequent monitoring. EPA is
requiring surface water systems to take
a minimum of four samples (rather than
two for groundwater systems) because
surface water is generally more variable
than ground water and. consequently.
additional sampling is required to
determine that the system is "reliably
and consistently" below the MCL
Today's rule allows a State, after a
baseline is established, to reduce the
quarterly monitoring frequency if the
system is "reliably and consistently"
below the MCL. "Reliably and
consistently" means that the State has
enough confidence that future sampling
results will be sufficiently below the
MCL to justify reducing the quarterly
monitoring frequency. Systems with
widely varying analytical results or
analytical results that are just below the
MCL would not meet this criterion. In all
cases, the system remains on a quarterly
sampling frequency until the State
determines that the system is "reliably
and consistently" below the MCL. EPA
is adopting this approach based on
comments received on the proposed rule
that suggested the EPA allow States to
modify the monitoring schedules in
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3562 Fadasal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
those systems which are less than the
MCL EPA believes this approach will
result in consistency among the
regulatory requirements for the different
classes of contaminants.
In the proposal, EPA required a
minimum of 12 quarters before the State
could reduce the monitoring frequency.
Several commenters suggested that a
minimum of 12 quarters after monitoring
had been increased by a trigger level
was too long. These commenters
suggested that EPA should require
sufficient monitoring to establish a
baseline. As noted. EPA believes that
the minimum number of samples
necessary to establish a baseline is two
for groundwater systems and four for
surface water systems. EPA is adopting
this approach because the Agency
agrees with commenters who pointed
out that systems whose analytical
results remain below the MCL do not
pose a health threat.
In the May 1989 proposal, a system
with any sample exceeding 50 percent of
the MCL for asbestos and pesticides/
PCBs would be required to take a
minimum of 12 quarterly samples. If all
12 were
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FadanQ Itogtotor / Vol. 56, Tto. HO / "Wednesday. January 80. 1991 / Rules and "Regulations 8583
chemical, the extent of source
protection, and Wellhead Protection
Program-reports. Systems with no
known "susceptibility" to contamination
based upon an assessment of the above
criteria may be granted a waiver by the
State. If "susceptibility" cannot be
determined, a system is not eligible for a
waiver. A system roust receive a waiver
by the beginning of the calendar quarter
in which it is scheduled to begin
monitoring. For example, if a system is
scheduled to begin monitoring in the
calendar quarter beginning January 1,
1993. it must receive a waiver by
December 31,1992 for reduced
monitoring to apply.
Several commenters requested that
EPA permit "area wide" or geographical
vulnerability assessment
determinations. Though EPA at this time
is skeptical that "area wide"
determinations can be conducted with
sufficient specificity to predict
contamination over a large area. EFA
will allow this option when States
submit their procedures for conducting
vulnerability assessments determine
"use" waivers.
EPA's goal is to combine vulnerability
assessment activities in other drinking
water programs with today's
requirements to create efficiencies. EPA
also desires to use the results of other
regulatory program requirements, such
as Wellhead Protection Assessments, to
determine a system's vulnerability to
VOC and pesticide/PCBs
contamination. Systems and States may
schedule today's asssessments with
sanitary surveys required under the
Total Coiiform Rule (54 FR 27546),
watershed assessments, and other water
quality inspections so that all
regulatory, operational, and managerial
objectives are met at the same time.
EPA intends to issue a guidance that
will give flexibility to States in
conducting vulnerability assessments
and allow them and local public water
systems to meet these and similar
requirements under the Wellhead
Protection Program, satisfying the
requirements of both programs with one
assessment. Additionally, this combined
assessment approach may be used to
meet similar requirements under the
evolving Underground injection Control
(UIC)—Shallow injection Well Program.
g. Relation to the Wellhead Protection
fWffPJ Program. The Agency planned to
integrate particular elements of the
Public Water System Wellhead
Protection, and UIC programs related to
contaminant source assessments around
public water supply wells prior to
receiving comments to that effect
Comments .received on the proposed
Phase II Rule reinforce and support this
interest. Specifically, the Agency plans
to prepare a guidance document on
groundwater contaminant source
assessment that merges the
vulnerability assessment of the PWSS
program for pesticides and VOCs with
the wellhead delineation and
contaminant source which can be used
to establish priorities of UIC wells. This
integration is expected to assist State
and local drinking water program
managers responsible for goundwater
supplies to more efficiently and
effectively administer the portion of
their programs addressing source
protection and will be the basis for
determining monitoring frequency. The
guidance will give States flexibility in
revising vulnerability/contaminant
source assessments, a concern of
several commenters.
Notably. Section 1428 of the SDWA
requires each State to submit a WHP
program for EPA review and approval.
The implementation of WHP programs
by States may be phased in to allow
resources to be used most effectively.
This matter can be addressed in the
State WHP submittal.
When States submit WHP programs
for approval in the future, program
documents should address how the
State will phase requirements for
Wellhead Protection Areas (WHPAs)
with ether PWSS regulations. In some
States, to be most effective, this program
integration may need to be
accomplished through a coordinating
agreement or other mechanism among
several State agencies. The guidance
would allow States to tailor then*
program provisions to conditions in the
States, within broad guidelines.
Information from the other related
groundwater programs (such as
Superfund, RCRA) will be useful in this
assessment, as pointed out by one
commenter. This information also
includes identification of sources not
regulated under federal programs, but
perhaps regulated by States, such as
septic tanks. Therefore, States may be
able to meet similar requirements of
these three programs through following
a general set of guidance procedures.
One commenter was concerned about
the difficulty of delineating wellhead
protection areas. A State may choose
from several methods to delineate
WHPAs. As long as the method is
determined to be protective, a State may
choose a simplified method described in
"Guidelines for the Delineation of
Wellhead Protection Areas" fjune 1987.
available from the Office of Ground-
Water Protection. U.S. EPA, EPA 440/6-
B7-O10). If a State desires more
information for use in the decision-
making process, it may choose more
sophisticated methods identified in the
"Guidelines." EPA had made available
to States and local agencies computer
software and training for use of the
"Guidelines" to make the process of
WHPA delineation less difficult.
Additionally, one commenter was
concerned about inclusion of recharge
areas in WHPAs. WHPAs may
incorporate recharge areas as long as
they are within the jurisdiction of the
agencies identified in the EPA-approved
programs. However, WHPAs must meet
the requirements of this rule if they are
to be used to make monitoring waiver
determinations. The State cannot accept
a WHP program in lieu of a vulnerability
assessment if the recharge area is not
covered to meet all the requirements of
this rule.
Once a WHPA is delineated, a State
may desire to apply a range of
assessment measures to define
hydrogeologic vulnerability within the
delineated area. A State may decide a
method of assigning priorities to the
public water systems based on
vulnerability, size, or other criteria
acceptable to EPA. While one
commenter indicated that DRASTIC
(one method of characterizing a
hydrogeologic setting) was useful in that
State for describing hydrogeologic
factors affecting the physical-geologic
vulnerability of an area, it does not take
the place of delineating the zone of
contribution to wells. Furthermore, the
use and disposal of chemicals and other
wastes are also factors affecting an
area's vulnerability to contamination.
EPA's Office of Ground-Water
Protection is developing a Comparative
Risk Ranking and Screening System to
help States and local water supply
managers prioritize potential
contaminant sources in carrying out
their programs for resource protection, a
concern of one commenter. This system
could also be used in setting monitoring
priorities but was not designed
specifically ior that application. As
another commenter indicated, the States
may use the regulatory mechanisms
available to them (RCRA permits,
NPDES permits) to determine the point
sources of regulated and potentially
contaminating, substances in or near
areas needing protection, such as
wellhead and recharge areas.
One commenter believed that drought
planning was more important than
contingency planning for alternate
sources of drinking water due to
contamination by chemicals. Drought
planning is very important in many
locations and needs to bs conducted.
However, section 1426 specifically calls
for contingency planning in the event of
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35®S Fodteral Sogoetsir / Vol. 58, No. 20 / Wednesday, January 30. 1991 / Rules and Regulations
contamination of public water wells in
wellhead protection areas. Contingency
planning could be integrated with
drought planning, and in many locations
the same sources of water may be used
in either situation as alternate sources
of drinking water.
One commenter was concerned about
funding for both the Wellhead
Protection Program and the Sole Source
Aquifer Demonstration Program in
Critical Aquifer Protection Areas. In
fiscal year 1SSO, EPA is supporting
State's activities in developing WHP
programs. To date, 29 States have
submitted documents for approval. Of
these, four State wellhead protection
program have been approved at this
time. It is expected that more programs
will be approved by the end of the fiscal
year.
With respect to the Sole Source
Aquifer Demonstration Program for
Critical Aquifer Protection Areas, no
funding has been appropriated for this
program for the period FY 1987-lSSO,
and as a result no such areas have been
identified.
h. Initial and Repeat Base Monitoring.
Initial monitoring is defined as the first
full three-year compliance period that
occurs after the regulation is effective.
As •discussed earlier, all systems must
monitor at the base monitoring
frequency unless a waiver is obtained.
The initial monitoring period for today's
regulation begins January 1.1593 and
ends December 31,1895. After the
system fulfills the initial (or first) base
monitoring requirement, it must monitor
at the repeat base frequency. Generally
the repeat base frequency is the same as
the initial monitoring frequency but in
several instances the base monitoring
frequency is reduced based on previous
analytical results (e.g., pesticides/PCBs).
In the May 1989 proposal, for the
VOCs and pesticides/PCBs, community
systems serving more than 10,000
persons were required to complete all
monitoring within 18 months of
promulgation, systems serving 3,300 to
10,000 persons were required to
complete monitoring within 30 months,
and systems serving fewer than 3,300
persons were required to complete
monitoring within 54 months. Non-
transient water systems were required
to complete all monitoring within 48
months. In today's rule EPA eliminates
the phase-in of monitoring based on
system size.
In today's rule, EPA requires all
systems to complete initial monitoring
(either by sampling or obtaining a
waiver) by December 31.1S95, which is
the end of the first compliance period. It
is possible that this change may delay
monitoring for oome large systems, but
otherwise all monitoring in this rule will
be completed approximately five years
after promulgation rather than the four
and one-half years in the May 22,1989
proposal. Most systems will monitor
sooner because today's rule does not
delay completion of initial monitoring
for the smallest systems (those less than
3,300) for four and one-half years.
Systems serving less than 3.300 persons
constitute approximately 80 percent of
the regulated systems, instead, under
today's rule, EPA is requiring the States
to establish a sampling schedule that
will result in approximately one-third of
the systems monitoring during each of
the three years of a compliance period.
States will have the flexibility to
designate which systems must monitor
each year based upon criteria such as
system size, vulnerability, geographic
location, and laboratory access. This
change will result in earlier completion
of initial monitoring for most systems.
EPA believes that allowing States the
discretion to schedule monitoring for
each system during the compliance
monitoring period will enable States to
manage their drinking water programs
more efficiently.
In cases where the State has not
adopted regulations by January 1,1S93,
and in States and on Indian lands where
EPA retains primary enforcement
responsibility, systems will be required
to complete monitoring within 12 months
after notification by EPA. In cases
where States have not yet adopted
regulations and EPA is the primacy
agent for this regulation, EPA intends to
use the priority scheme envisioned by
the State to minimize the disruption to
the regulated community when the State
does adopt the requirements and
schedules systems to monitor.
Once a system is scheduled for the
first, second, or third year of &
compliance period, the repeat schedule
is set for future compliance periods. For
example, if a system is scheduled by the
State to complete the initial base
requirement by the end of the first year,
all oubsequent repeat base monitoring
for that system must be completed by
the end of the first year in the
appropriate three-year compliance
period. This is necessary to prevent
systems from monitoring in the first year
of the first compliance period and the
third year of the repeat base period.
4. Monitoring Frequencies
a. Inorganics (1) Initial and Repeat
Base Requirements In the May 1989
proposal, surface water systems were
required to monitor annually and
groundwater systems every three years.
Most commenters supported that
frequency. The monitoring frequencies
in today's rule are identical to these
proposed frequencies. Systems will be
required to take the initial base sample
for each inorganic during the initial
compliance period of 1993 to 1995
(subject to State scheduling). Surface
water systems on annual sampling
schedule are required to start in 1993.
(2) Increased Monitoring. EPA has
added a requirement that systems that
exceed the MCL (either in a single
sample or with the average of the
original and repeat sample) and which.
consequently, are out of compliance
must immediately (i.e., the next calendar
quarter after the sample was taken)
begin monitoring quarterly. Systems
must continue to monitor quarterly until
the primacy agent determines that the
system is "reliably and consistently"
below the MCL Ground water systems
must take a minimum of two samples
and surface water systems must take a
minimum of four samples after the last
analytical result above the MCL, before
the State can reduce monitoring
frequencies back to the base
requirement (i.e., annually for surface
systems and every three years for
groundwater systems).
EPA is promulgating this change for
several reasons. First it is consistent
with the monitoring requirements
contained elsewhere in this rule that
more frequent monitoring occur in
instances of non-compliance. Second,
EPA believes that systems that are out
of compliance should monitor more
frequently to determine the extent of the
problem. If EPA had not made this
change, groundwater systems that
exceed the MCL could continue to
monitor every three years. EPA believes
the previous frequencies for ground and
surface systems were not protective of
public health in those cases where
systems exceeded the MCL.
(3) Decreased Monitoring. In the May
1989 Notice. EPA proposed that systems
be allowed to reduce the monitoring
frequency to no less than 10 years
provided a system had previously taken
three samples that were all less than 50
percent of the MCL. States should base
their decision on prior analytical results,
variation in analytical results, and
system changes such as pumping rates
or stream flows/characteristics.
EPA receives numerous comments on
the 50 percent trigger for reduced
monitoring with most commenters
opposing the 50 percent trigger, calling it
arbitrary and with no health
significance. Other commenters
suggested that the 50 percent trigger
would result in a pseudo MCL. After
reviewing the comments, EPA has
decided to eliminate the 50 percent
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Federal Register / Vol. 56, No. 20 / Wednesday. January 30, 1991 / Rules and Regulations 3565
trigger and change the requirement to
three previous compliance samples
(including one that was taken after
January 1.1990) that are "reliably and
consistently" less than the MCL to give
the States additional flexibility to decide
which systems are eligible for reduced
monitoring. Systems meeting this
criterion are eligible for reduced
monitoring (e.g., a waiver).
Most commenters supported the 10-
year time frame as a reasonable
monitoring frequency for reduced
monitoring. Because EPA is adopting a
3/6/9 compliance cycle, EPA is changing
the maximum reduced monitoring
frequency from the proposed 10 years to
9 years to gain consistency in its
regulations. EPA believes this change
will have a minimal impact on systems.
EPA is requiring one of the three
previous samples to be taken since
January i, 1990. The other two samples
could be taken at any time after June 24,
1977 when monitoring for inorganics
started. Because the reduction in
monitoring to every nine years begins in
the 1993-2001 compliance cycle. EPA
believes that one sample must be recent
(i.e., taken after January 1,1990) to
preclude unduly long time frames
occurring between samples. Systems
receiving a waiver may monitor at any
time during the nine-year compliance
cycle, as designated by the State.
EPA believes that systems should use
the same criteria outlined in the
preamble of the proposal (as modified
above) to reduce monitoring. Several
commenters suggest that systems that
meet the criteria automatically qualify
for a waiver without State approval.
EPA has rejected this approach because
it believes that State approval is crucial
in certain circumstances such as where
the system is adjacent to a toxic waste
site or ether anthropogenic sources of
contamination. EPA anticipates that in
most cases, States will grant waivers
expeditiously.
b. Asbestos—(1) Initial and Repeat
Base Requirements. In the proposal,
systems were not required to monitor for
asbestos unless the State determined
that the system was vulnerable to
contamination within 16 months of
promulgation. If vulnerable, systems
were required to take one sample within
five years of promulgation. EPA also
proposed an alternative approach
requiring all systems to monitor unless
the system conducted a vulnerability
assessment and the State determined
the system was not vulnerable to
asbestos contamination.
Most commenters supported the
proposed approach, although several
commenters suggested that the
alternative approach was preferable.
EPA, in today's rule, is promulgating the
alternative approach, which requires all
systems to monitor for asbestos during
the 1993 to 1995 compliance period. This
approach, as discussed previously,
results in an enforceable requirement,
but the number of systems judged to be
vulnerable should be the same as with
the proposal, provided vulnerability
assessments are conducted.
The base repeat frequency is once in
the first three-year monitoring period of
each nine-year cycle, which means that
after the initial base monitoring
requirement is completed, systems
would not be required to monitor again
until the 2002 to 2005 compliance period.
EPA has not eliminated the repeat base
requirement because of concern that
there may be occurrence in a limited
number of systems. Systems that are not
vulnerable would continue to be eligible
to receive waivers. EPA is requiring
infrequent base monitoring requirements
because of the low probability of
occurrence, the limited analytic
capabilities to measure asbestos, and
the high analytical costs, and because of
regulatory activities such as the
corrosion control activities and
asbestos/cement pipe ban. which EPA
believes will reduce the future
occurrence of this contaminant.
(2) Increased Monitoring. In the May
1989 proposal, ground and surface water
systems exceeding 50 percent of the
MCL in the initial sample were required
to monitor every three years and
annually, respectively. Several
commenters suggested that the source of
the water was not a valid criterion for
determining repeat monitoring
frequencies. EPA agrees and has
modified the rule as described below to
use the analytical result as the "trigger"
for any repeat monitoring.
Most comments on the asbestos
monitoring frequencies were in response
to the 50 percent trigger for repeat
monitoring. For the reasons discussed
earlier, EPA has decided to eliminate
the 50 percent trigger and use the MCL
to determine repeat monitoring
frequencies. EPA is prescribing the
"baseline" approach described above
for inorganics. Systems that exceed the
MCL must initiate quarterly monitoring
in the next calendar quarter. When the
State determines that the system is
"reliably and consistently" less than the
MCL (a minimum of two samples for
ground water and four for surface
water), then the system can reduce its
monitoring frequency to that set by the
State but not less than the base
requirement.
(3) Decreased Monitoring. Today's
rule allows States to grant waivers
based on a vulnerability assessment by
systems that considers contamination in
the raw water supply and/or from the
corrosion of asbestos/cement pipe
(including pipe tapping and repair) in
the distribution system. Systems not
receiving a waiver must monitor at the
base frequency. Because monitoring is
not required in the second and third
three-year periods, no waiver is needed
in those monitoring periods.
Most commenters agreed with EPA's
criteria for reducing monitoring.
Consequently, the requirements are
promulgated as proposed.
c. Nitrate (1) Initial and Repeat Base
Requirements.—(A) Community and
Non-Transient Water Systems. The
proposed rule required ground and
surface water systems to monitor at
annual and quarterly intervals,
respectively. Commenters were mixed in
both supporting and opposing the
increased frequency compared to the
current requirements. Many commenters
said that although nitrate occurrence
was widespread, nitrate levels over time
were steady. After reviewing the
comments and reviewing occurrence
data, EPA is convinced that nitrate
occurrence is widespread and often has
seasonal fluctuations resulting from
factors such as when fertilizer is applied
and rainfall events. Consequently, EPA
believes nitrate monitoring frequencies
should be increased, as proposed, to
protect against the acute effect of
methemoglobinemia. Therefore, today's
rule retains the requirements as
proposed. Under today's rule,
monitoring for surface water systems
will begin in the first quarter of 1993:
CWS and NTWS groundwater systems
and transient non-community systems
(TWSs) must take one sample annually
beginning in 1993.
The proposed rule required systems to
monitor at the time of highest
vulnerability, which most commenters
suggested they were unable to
determine. Since EPA agrees that
determinning the time of highest
vulnerability is difficult the Agency has
decided to change the time when
monitoring must be conducted. When a
system changes its monitoring frequency
from quarterly to annually, the annual
sample must be taken in the calendar
quarter(s) that previously yielded the
highest previous analytical result. For
example, if a system sampled in the
first, second, third, and fourth quarters
in the previous year and the analytical
results were 1 mg/1, 3 mg/1. 4 mg/1. and
2 mg/1, respectively, the system is
required to take its annual sample in the
third quarter in the next year. Today's
rule considers the third quarter the time
of "highest vulnerability" for the system.
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3566 Federal -Regjrtar / VoL 56. No. 20 / Wednesday. January 3D. 1991 /Rules and Regulations
(B) Transient Non-Community Water
Systems. The proposed rule required
ground and surface water systems to
monitor at three- and one-year intervals.
In the proposal, EPA requested comment
on the frequency of monitoring
requirements for transient system. Most
commentcrs supported the proposed
frequencies; however, several
conirnenters suggested that additional
monitoring was appropriate since nitrate
io regulated as an acute toxin.
EPA now believes that a monitoring
frequency of evsry three years is not
protective of health for nitrate, an acute
toxin which is ubiquitous. Based on a
review of the comments, EPA has
decided to require all TWS systems
(including groundwater systems) to
monitor annually. Because analysis of
nitrate is relatively inexpensive and a
sample can be taken at the time the
system takes a coliform sample, EPA
believes the impact of this change on
TWS will be minimal yet offer greater
health protection. Consequently, EPA is
promulgating annual sampling for
groundwater systems.
(2) Increased Monitoring (CVfS,
NTWS. TWS). The proposed rule
required groundwater CWSs and
NTWSs to monitor at quarterly
frequencies when the concentration is
greater than 50 percent of the MCL for
any one sample. The sampling frequency
remains quarterly until Tour consecutive
samples are less than 50 percent of the
MCL As discussed earlier, most
commenters suggested deleting the 50
percent trigger for increased or
decreased monitoring. Even though
elsewhere in this rule the 50 percent
trigger is eliminated. EPA has decided to
retain the 50 percent trigger for
increased nitrate monitoring in the case
of nitrate and also to extend this
requirement to TWSs. For this
contaminant, EPA believes the 50
percent trigger constitutes an early
warning signal for an acute
contaminant Although EPA considered
other options as triggers for increased
monitoring, such as the level of
detection or the MCLJEPA believes
these axe not appropriate both because
nitrate can be detected at levels far
below the MCL and because the MCL
represents the level where above this
level acute effects may occur in some
individual. Consequently, EPA believes
that 5 mg/1 remains the best trigger for
increased nitrate monitoring. EPA
believes that it is appropriate to extend
the increased monitoring frequencies to
include transient water systems because
of the acute hazard posed by this
contaminant
EPA has decided to modify the
requirement for decreased monitoring.
In today's rule, a system that exceeds 50
percent of the MCL in any sample must
remain on a quarterly monitoring
schedule until a minimum of four
consecutive samples are judged by the
State to be "reliably and consistently"
less than the MCL EPA believes that
this change allows States the flexibility
to reduce the monitoring for those
systems that, while they have detectable
nitrates, are very unlikely to exceed the
MCL until the next monitoring cycle.
(3) Decreased Monitoring (Surface
CWS and NTWS). The proposed base
monitoring requirement for surface
water systems was quarterly. A
reduction to annual sampling was
permitted when four consecutive
samples were less than 50 percent of the
MCL For the reasons explained above,
EPA has decided to change the proposal
somewhat to allow surface water
systems to decrease to an annual
frequency provided four consecutive
samples are "reliably and consistently"
less than the MCL
d. Nitrite (1) Initial and Repeat Base
Requirements. In the proposal, systems
were required to monitor for nitrite at
the same frequencies as for nitrate.
After reviewing comments and
reexaminrng limited occurrence
information (i.e., State of Wisconsin,
Public Water Supply Data, 1370), which
indicates occurrence above 50 percent of
the MCL was very infrequent, EPA has
decided to require all systems to
monitor once for nitrite in the first
compliance period (1993 to 1995). If the
analytical result is less than 50 percent
of the MCL (0.5 mg/1), additional
monitoring is at State discretion.
However, future measurements under
the nitrate requirement will mandate
combined measurement of nitrate plus
nitrite, both measured as nitrogen using
a single analytical technique.
If the analytical result in the initial
sample is equal to or greater than 50
percent of the MCL (i.e.. £ OJ mg/1),
systems must then monitor quarterly
(with a nynimnm of four samples) until
the State determines that the system is
"reliably and consistently" less than the
MCL After that determination, systems
must monitor at an annual frequency.
e. Volatile Organic Contaminants
(VOCs)—(I) Initial and Repeat Base
Requirements. In the VOC rule
promulgated in July 1637, EPA required
all systems to take four consecutive
quarterly samples. Groundwater
systems that conducted a vulnerability
assessment and were judged not
vulnerable, however, could atop
monitoring after the first sample
provided no VOCs were detected in that
initial sample. Repeat frequencies for all
systems vary by system size, detection,
and vulnerability status.
EPA has made several changes to the
proposed VOC requirements. EPA is
also today proposing to amend the July
1987 monitoring requirements for VOCs
tc streamlining the requirements and to
make all VOC requirements consistent.
In the May 1989 notice and in the VOC
regulations promulgated in July 1987,
distinctions in base requirements were
made between ground and surface
water systems, less than and more than
500 service connections, and vulnerable
and non-vulnerable systems. EPA, in
streamling the requirements in today's
rule, will require all systems to take four
quarterly samples. Systems that do not
detect VOCs in the original round of
quarterly sampling are required to
monitor annually beginning in the next
calendar year after quarterly sampling is
completed. The State may allow
groundwater systems •which conducted
three years of sampling and did not
detect VOCs to take a single sample
every three years. For example, systems
which complete quarterly monitoring in
calendar year 1993 are required 1o being
annual monitoring in 1994. EPA is
making this change for several reasons.
First, the occurrence of VOCs in
approximately 20 percent of systems
indicates that shortening the time frame
between when each sample is collected
for vulnerable groundwater systems
from every tliree tc five years to an
annual sample is appropriate. Second,
the cost of analysis for VOCs has
decreased since the original proposal.
Most VOC analyses now cost
approximately $150 per sample versus
the $200 per sample EPA estimated in
the 1937 VOC rule. Trihalomethanes
(THMs) may also be measured in these
samples, thereby creating efficiencies
with current and future THM monitoring
requirements. Consequently, the
monitoring burden on most systems is
less than previously thought. Third, most
commenters preferred annual
monitoring, stating that quarterly
monitoring presented managerial and
logistical problems. Where groundwater
systems have a demonstrated .history of
non-detects for VOCs, EPA believes a
reduction of monitoring to one sample
during each compliance period, if
allowed by the State, is protective of
health. For the above reasons. EPA is
promulgating the above monitoring
requirement changes.
In the May 1989 notice, EPA requested
comment on whether vulnerable
systems may take only one sample L no
VOCs are detected in the initial year of
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Federal Register / Vol. 56. No. 20 / Wednesday, January 30. 1991 / Rules and Regulations 3567
monitoring. EPA's intent was to require
quarterly sampling in vulnerable
systems, but most commenters opposed
a change to more frequent monitoring.
Based on the comments received, EPA is
requiring vulnerable systems to take an
annual sample beginning in 1993
(instead of four quarterly samples) if no
VOCS were detected in the initial (or
subsequent) monitoring.
In today's rule. EPA is requiring
systems to conduct an initial round of
quarterly monitoring. In the 1987 VOC
rule, however, EPA required systems to
conduct unregulated contaminant
monitoring for all VOCs contained in
today's rule, and stated that those
results could be grandfathered in for
future regulatory requirements.
Consequently, EPA will allow systems
that have conducted monitoring under
§ 141.40 to use those results to satisfy
the initial monitoring requirement for
those VOCs included in today's rule
even if a single sample, rather than four
quarterly samples, was taken. Only new
systems, existing systems with new
sampling points, or systems that did not
conduct monitoring under § 141.40 prior
to December 31,1992, are required to
conduct initial base monitoring for the
VOCs in today's rule during the 1993-
1995 compliance period.
(2) Increased Monitoring. In the
proposal, systems detecting VOCS
(defined as any analytical result greater
than 0.0005 mg/1) were required to
monitor quarterly. In today's rule, EPA
is requiring systems that detect VOCs to
monitor quarterly until the State
determines that the system is "reliably
and consistently" below the MCL
However, groundwater systems must
take a minimum of two samples and
surface water systems must take a
minimum of four samples before the
State may reduce the monitoring to the
base requirement (i.e., annual sampling)
Systems remain on an annual
sampling frequency even if VOCs are
detected in subsequent samples, unless
an MCL is exceeded (or if the State
otherwise specifies). In this case, the
system returns to quarterly sampling in
the next calendar quarter until the State
determines that the new contamination
has decreased below the MCL and is
expected to remain reliably and
consistently below the MCL. This
determination shall again require a
minimum of four quarterly samples for
surface water systems and two
quarterly samples for groundwater
systems.
EPA is making this change because
some systems may detect VOCs at a
level slightly above the detection limi.
EPA believes that where the State can
determine that contamination is
"reliably and consistently" less than the
MCL. those systems should be able to
return to the base monitoring
requirement (i.e., annually). Giving
States the discretion to determine
whether systems meet this criterion may
allow States to give monitoring relief to
some systems.
(3) Decreased Monitoring. States may
grant waivers to systems that are not
vulnerable and did not detect VOCs
while conducting base monitoring.
Vulnerability must be determined using
the criteria specified above in the
discussion of vulnerability assessments.
EPA anticipates that most systems will
not be able to qualify for a "use" waiver
because of the ubiquity of VOCs.
However, systems conducting an
assessment that considers prior
occurrence and vulnerability
assessments (including those of
surrounding systems), environmental
persistence and transport, source
protection, Wellhead Protection
Assessments, and proximity to sources
of contamination may apply to the State
for a "susceptibility" waiver. If the
waiver is granted, systems are required
to take one sample and update the
current vulnerability assessment during
two consecutive compliance periods
(i.e., six years). The vulnerability
assessment update must be completed
by the beginning of the second
compliance period. EPA is increasing
the time frame from five to six years to
bring the five-year monitoring frequency
in the proposal in line with the 3/6/9/-
year frequencies specified in the
standard monitoring framework.
EPA proposed that States have the
discretion to set subsequent frequencies
in systems that did not detect VOCs in
the initial round of four quarterly
samples and that are designated as not
vulnerable based on assessment Most
commenters supported this provision,
and it is promulgated as proposed. The
repeat monitoring frequency for
groundwater systems meeting this
criteria shall be not less than one
sample every six years as discussed
above. For surface water systems
meeting this criteria, the repeat
frequency is at State discretion.
/. Pesticides/PCBs—{\) Initial and
Repeat Base Requirements. In the May
1989 proposal, systems were not
required to monitor unless the State, on
the basis of a vulnerability assessment,
determined the system vulnerable. If
vulnerable, systems were required to
take four consecutive quarterly samples.
EPA requested comment on an
alternative approach that would require
all systems to monitor for all
contaminants. As discussed above.
today's requirements specify that all
systems must take four quarterly
samples every three years. However, all
systems are eligible for waivers from the
quarterly monitoring requirement, as
discussed in the section on decreased
monitoring below.
Most comments on the proposal
revolved around two issues—the
requirement that systems monitor
quarterly and the requirement that all
systems monitor at the time of highest
vulnerability. Many commenters stated
that quarterly monitoring was not
necessary to detect changes in
contamination. Many commenters
recommended annual monitoring for
pesticides. After reviewing the
information and comments submitted.
EPA believes that quarterly monitoring
remains the best scheme to determine
contamination. Occurrence information
available to EPA indicates that seasonal
fluctuations from runoff and
applications of pesticides may occur;
thus, quarterly monitoring is better than
annual monitoring to determine
pesticide contamination. In some cases,
it may be appropriate to monitor at
greater frequencies than those specified
by today's rule to better determine
exposure. States and systems have the
option to monitor at greater frequencies
than the federal minimums.
Most commenters opposed the
requirement to monitor at the time of
highest vulnerability, stating that highest
vulnerability cannot be predicted or
determined. Several commenters stated
that the requirement to monitcr at the
time of highest vulnerability was
unenforceable. EPA agrees and
eliminates this requirement from today's
rule. However, States are advised to
examine sampling practices of systems
to assure that periods of likely
contamination are not avoided. This is
especially true for surface water
systems monitoring for pesticides after
rainfall and/or application of pesticides.
In the May 1989 notice. EPA proposed
that systems conduct repeat monitoring
every three or five years, depending on
system size and ground/surface
distinctions, in today's rule, the repeat
monitoring frequency for all systems is
four consecutive quarterly samples each
compliance period. However, EPA has
made several adjustments for systems
that do not detect contamination in the
initial compliance period. After the
initial monitoring round is completed,
systems that serve >3,300 persons may
reduce the sampling frequency to two
samples in one year during each
compliance period. Systems serving
< 3.300 persons may reduce the
sampling frequency to one sample. EPA
has increased the frequency small
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3568 Federal Register / Vol. 56, No. 20 / Wednesday, January 30. 1991 / Rules and Regulations
systems must monitor in this rule from
every five years to every three years,
because EPA believes that this change
will offer greater health protection. EPA
believes that every six years is too long
an interval to determine changes in
consumer exposure. In addition, because
EPA has coupled this change with
revised procedures for granting "use"
waivers, the impact of this change will
be minimal
EPA ha» made die granting of "use''
waivers for pesticides easier in this rule
and will permit States-1» grant "area
wide" or "Statewide" waivers baaed
upon pesticide use information. EPA
anticipates in adopting this scheme,
along with the other change* outlined in
today's ruler that many system* vriB be
able to obtain a "\ree~wamr. For those
system* not able to obtain a waiver (i.e.,
vulnerable systems), EPA believer it is
appropriate to monitor at three-year
intervals to determine-contamination.
(2) Increased Monitoring. In the May
1989 notice, systems with less than 500
service connections that detect
contamination were required to monitor
annually. Systems with more than. 500
service connections that delect
pesticides are required to monitor
quarterly. EPA defined detection as
greater than 50 percent of the MCL
Most comments revolved around the 50
percent trigger. As discussed above,
EPA is redefining-detection for
pesticides to mean using the method
detection limit (see table 24). EPA
believes it is appropriate to use the
method detection limit as the trigger for
reduced monitoring because detection
implies that a pathway to contamination
exists. Consequently, additional
monitoring is required to determine the
extent and variability of pesticide
contamination. In today's rule, all
systems that detect peatfcides/PCBs
must monitor quarterly until a reliable
baseline has been established.
TABLE 24.—METHOD DETECTION LIMITS—
PESTICIDES/PCBs
TABLE 24.—METHOD DETECTION LIMITS—
PESTICIDES/PCBs—Continued
ContBrreiunt
AldKwbeulta
Cotoofuran..
OOyomccMoreprapens (OBCPf_
Ethytone dibramida.(EDB)
Meptachtor —
He
«P"
UMhoxycnlo
Ostoctkm limit
0.0005 mg/l
e.flOOSmo/l
mo/1
OtOOOl mo/i
a.aaoftmg/1
0.002 mg/l
0.00002 mg/t
OOMf mg/l
Contingent
PsntttchrOfophonol .——««*...——..•—
ToxAph6f>6 ...—. ............................
2.4.STP (Sltvex)
uotecttoff wntt
O.ooot mg/i
0.00001 mo/I
O.OOT rng/l
0.0002 mg/»
0.00004 mg4
O.OOOOZ.mg/1
mart
aeoat mg/i
As described previously, upon
detection, all systems must immediately
begin quarterly monitoring. The State
may reduce the system to annual
monitoring after determining it is
"reliably and consistently" below the
MCL A reduction to> annual monitoring
may occur after a minimum of two
samples for grouadwater and four
samples for surface water system*
After three years of annual monitoring
which remains "reliably and
consistently" below the MCL, systems
can return to the base monitoring
requirement (Le., four quarterly samples
every three years).
(3) Decreased Monitoring. Systems
that obtain a waiver from the monitoring
requirements are not required to
monitor. All systems are eligible for
waivers in the first three-year
compliance period of 1083 to 1995, As
discussed above, EPA has simplified the
vulnerability assessment procedures by
allowing the system to assess whether
the contaminant has bees used,
transported, mixed; or stored in the
watershed or zone of influence. Where
previous pesticide/PCB use in the area
can be ruled out systems may apply to
the State for a use waiver. EPA's intent
in promulgating' this cMfly is to make it
easier for systems to obtain waivers in
those situations where the-chemical has
not been used. States may be able to
determine that the entire State or
specific geographic areas-of the State
have not used the contaminant and
consequently granted "area wide"
waivers. Systems that cannot determine
use may still qualify for a waiver by
evaluating susceptibility according, to
the criteria discussed in the VOC
section above. Waivers must be
renewed every threo years.
EPA requested comment*) on whether
systems that did not detect canceled
pesticides in the initial monitoring round
should be presumed to be non-
vulnerable and therefore not required to
monitor. After-reviewing the comments.
and information on iHegsi psstkide use,
EPA continues- to believe that no
occurrence improves tha likelihood that
the Stale will grant a warmer from
continued monitoring of a canceled
pesticide. Due to posoibl* persistence in
the environment, however, EPA does> not
agree with commenters who believe that
waivers should be granted
automatically.
5. Other Issues
a. Compliance Determinations.
Several commenters suggested that for
a compliance determination, a single
sample or four quarterly samples are not
representative of water delivered to
consumers. Several commenters
suggested that EPA adopt an averaging
period of longer than one year for
compounds posing chronic health
hazards. EPA continues to believe that
any excursion above an MCL presents a
risk to health and should be addressed
immediately. However, in a practical
sense, moat systems would not
immediately install treatment until
establishing a baseline based on
additional mpnj^nring to determine the
extent of the problem. Several years will
elapse after a violation before treatment
is installed. Consequently, die conmrn
of the commeBter that a single sample
may result in. treatment is- unfounded.
EPA wiahes to point out that water
systems can always submit a sampling
plan (subject to State approval) that
includes more monitoring than the
minimum established by EPA. if that
will result in a better representative
sample.
Several oammenters opposed the
proposed requirement that a system is
immediately out of compliance and must
give public notice if the initial or the
total of subsequent samples is more
than four times the MCL The
commenters-were concerned that non-
compliance may Debased on a single
sample. EPA points out that any
quarterly sample thai exceeds the MCL
by four times would result in an annual
average that exceeds the MCL EPA
continues to believe that this approach
gives early warning to consumers that a
health problem may exist EPA has
clarified how the annual average is
calculated by specifying that any
analyses below the detection limit shall
be calculated as zero.
Several commenters opposed the
requirement that if a single sampling
point is out of compliance, then the
entire system is out o£ compliance. As
previously stated. EPA has adopted this
policy because EPA determines system
compliance, not """p1"^ point
compliance,
EPA wishes to point out and clarity
that ones n system is waived from
specific measurement of nitrite, as
discussed above, compliance wiB b*
determined through a measurement of
combined nitrate- and nitrate (measured
-------
Federal Register / Vol. 56, No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3569
as N). The MCL for this combined
measurement remains at 10 mg/1 as N.
b. Confirmation Samples. EPA
proposed that if an analytical result
greater than 10 mg/1 for nitrate and 1
mg/1 for nitrate indicates that the
system may exceed the MCL, then that
system must take a confirmation sample
within 24 hours of notification of the
analytical result. Results from both
samples must be reported to the State
within two weeks of the date the initial
sample was taken. Most conunenters
opposed the requirement to take a
confirmation sample within 24 hours of
notification, stating that it was
impractical to require a system to
monitor that quickly. EPA agrees with
the commenters and has modified
today's rule to allow systems in which
the first eaciple exceeds the MCL to
notify the public within 24 hours of
receipt of the analytical results through
posting, mail notification, or radio/TV
that the system may be in violation. If
the system decides to take this option,
then it must take a confirmation sample
within two weeks of the original
notification.
c. Compositing. In the May 1989
proposal EPA allowed systems, at the
discretion of the State, to composite up
to five samples. Compositing must be
done in the laboratory. Most
commenters supported compositing as a
methodology to cut costs. In this final
rule. EPA is limiting compositing among
different systems to only those systems
serving fewer than 3,300 people.
Systems serving greater than 3.300
persons will be allowed to composite
but only within their own system. EPA
also requested comments on whether
State discretion on compositing is
necessary or whether systems can
composite automatically without State
approval. Several States opposed this
change; consequently, the final rule is
unchanged from the proposal. EPA
believes that compositing is to be used
only when cost savings are important
end systems alone should not make that
determination.
d. Asbestos. Some commenters were
confused by the wording used to ipecify
sampling points in a distribution system
for measuring asbestos when a b/stem
or part of a system is judged vulnerable.
EPA wishes to clarify that collecting a
sample at a consumer tap is rot
necessary. It is sufficient to collect at a
convenient place in those parts of the
distribution system that have been
deemed vulnerable to asbestos
contamination.
0. Unregulated Contaminant Monitoring
EPA proposed requirements to
monitor for other "unregulated"
contaminants. "Unregulated"
contaminants are those contaminants
for which EPA establishes a monitoring
requirement but which do not have an
associated MCLG, MCL, or treatment
technique (see table 25). EPA may
regulate these contaminants in the
future.
TABLE 25.—UNREGULATED INORGANIC
AND ORGANIC CONTAMINANTS
I EPA analytical metnod
Organic contaminants
Aldnn
Benzo(a)pyrane
Butachlor
Cert>«fy1
Dalapon
Di-2(ethylhexyl)adipate
O-
2(ethythexyl)phmalates.
Dicamba
Oeldnn
Dinoseb
Oquat
Endottw.ll
Glyphosate
Hexachlorobenzene
Hexachlorocyclopema-
owne.
3-Hydroxycarbofuran
Melhomyl „
Meto"achlor
Metrlbuzin
Oxamyl (vydate)
Pidoram. _
Propacfilof
Simazine „ ,
2.3.7.8-TCDD (Dtoxin)
Beryllium _
Nickel..
Sutfate ....
Thallium
Cyanide.
505. 508. 525
525. 550. 550.1
507. 525
531.1
515.1
506. 525
506. 525
515.1
505. 500. 515
515.1
543
548
547
505. 508. 525
505. 525
531.1
531.1
507. 525
507. 508. 525
531.1
515.1
507. 525
505, 507. 525
513
Graphite Furnace Atomic
Absorption: Inductively
Coupled Plasma.
Graphite Furnace Atomic
Absorption: Inductively
Coupled Mass
Spec Um lie try Plasma:
Speetfophotometric.
Atomic Absorption:
Inductively Coupled
Plasma: Graphite
Furnace Atomic
Absorption.
Colorimetnc.
Graphite Furnace Atomic
Absorption: Inductively
Coupled Mass
Spectrometry Plasma.
Spectrophotometric.
EPA proposed monitoring
requirements for approximately 110
"unregulated" organic chemicals and six
inorganic chemicals. These
"unregulated" contaminants were
divided into two priority groups. The
monitoring requirements for
contaminants in the priority #1 group
only apply to those systems vulnerable
to the contaminant. EPA proposed that
States may require additional
monitoring for those contaminants in the
priority #2 list based upon local
concerns and priorities.
For priority #1 contaminants. EPA
proposed that States must conduct a
vulnerability assessment within 18
months of promulgation for each
contaminant. The vulnerability
assessment would determine the
specific contaminants for which
community and non-transient systems
must monitor. EPA also proposed an
alternative scheme that would require
all systems to monitor unless a
vulnerability assessment determined
that the system was not vulnerable.
Most commenters supported the
concept of vulnerability assessments to
determine which systems monitor. EPA,
in today's rule, is making several
changes to the proposal based on the
comments. First, EPA is adopting the
alternative monitoring scheme that
requires all systems to monitor for the
organics unless a vulnerability
assessment determines the system is not
vulnerable. Second, all systems must
complete the monitoring by the end of
the first monitoring period (i.e.,
December 31,1995) rather than four
years after publication of the rule in the
Federal Register, as discussed
previously. Third, EPA is dropping the
priority #2 list of contaminants for
which States may use their discretion in
monitoring. Systems, however, are
encouraged to monitor for all
contaminants contained in a specific
analytical methodology. Fourth, EPA is
adding three contaminants, which were
proposed in the list of 24 contaminants
on July 25.1990 (55 FR 30370). Fifth. EPA
is eliminating 2,4.5-TP (Silvex) from the
list, as it is a regulated contaminant in
today's rule.
Most conunenters expressed concern
about the resource requirements for
conducting vulnerability assessments
for the unregulated contaminants. EPA
believes the incremental resources
required to conduct vulnerability
assessments for unregulated
contaminants are minimal because all
systems will be required to monitor
and/or conduct a vulnerability
assessment for the regulated
contaminants.
E. Variances and Exemptions
1. Variances
Under section 1415(a)(l)(A) of the
SDWA, EPA or a State that has primacy
may grant variances from MCLs to those
public water systems that cannot
comply with the MCLs because of
characteristics of their water sources. At
the time a variance is granted, the State
must prescribe a compliance schedule
and may require the system to
implement additional control measures.
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357ft Fotarai Remitter / Vol. 56, No. 20 / Wednesday, January 30, 1991 / Roles and Regulations'
The SETWA requires that variances may
only be granted to those systems that
have installed BAT (aa identified by
EPA). However, in limited situations a
system may receive a variance if it
demonstrates that the BAT would only
achieve a de minimus reduction in
contamination (see § 142.62(d}). Before
EPA or a Slate issues a variance, it must
find that the variance will not result in
an unreasonable risk to health.
Under section 1413{a)(4) of the Act.
States with primacy that choose to issue
variances must do so under conditions
and in a manner that is no less stringent
than EPA allows under section 1415.
Before a State may issue a variance, it
must find that the system is unable to (1]
join another water system, or (2J
develop another source cf water and
thus comply fully with all applicable
drinking water regulations.
The Act permits EPA to vary the BAT
established under section 1415 from that
established under section 1412 based on
a number of findings such as system
size, physical conditions related to
engineering feasibility, and the cost of
compliance. Paragraph 142.62 of this rale
lists the BAT that EPA has specified
under section 1415 of the Act for the
purposes of issuing variances. This list
mirrors the proposed list except that
electrodialysis is considered BAT for
barium, nitrate, and selenium as
discussed in "Selection of Best
Available Technology" above.
EPA received several comments on its
proposed list of section 1415 BAT. The
commenters agreed with EPA that
coagulation/filtration and lime softening
should be excluded as BAT for those
systems serving <500 service
connections. In the proposal, EPA
requested comment on whether reverse
osmosis, activated alumina, and ion
exchange should be considered BAT for
small systems because of the relatively
high costs of these technologies. EPA
also stated that it waa continuing to
evaluate what costs are feasible for
public water systems and that it was
currently examining alternative
affordability criteria. EPA also
requested cornmems on whether PTA
should be BAT for DBCP and EDB
because of high air-to-water ratios
resulting in increased costs.
In the proposal, EPA based its cost
estimates on designs reflecting best
engineering practice. Some of the
assumptions underlying these cost
estimates-'may be unrealistic.
considering the nature of small water
systems-and their ability to procure,
finance, or operate-facilities, la other
cases, the assumptions did not reflect
EPA's best understanding of design and
average flews in. water systems, the cost
of waste treatment or the costs of
engineering more likely to be used by
small water systems. A reexamination
of these assumptions has led EPA to
conclude that the costs of treatment to a
water system and its customers may lie
within a very wide range depending on
site-specific conditions and
requirements.
EPA has produced a draft report
entitled "Small System Technology Cost
Revisions" (U.S. EPA, Office of Drinking
Water, May 1990), which describes the
cost of treatment trains that are more
likely to be used in small water systems.
The costs in that report are based on
engineering assumptions different from
those used to cost very small system
technologies at the time of the proposal
Differences between engineering
assumptions and those used in the
proposal include, for example, purchase
of prebuilt sheds rather than full
construction of a shed.
Cost estimates in the "Small System
Technology Cost Revisions" draft report
of technologies with contaminant
removal capability equivalent to those
discussed in the proposal are
significantly lower. For example, the
cost of removing chromium using two-
bed ion exchange treatment in a water
system serving 25-100 people was listed
in the proposal at $3.40/1,000 gallons. As
a result of updating flow and waste
disposal assumptions, the cost is now
estimated at $10.16/1.000 gallons. This is
equivalent to about $1,000 per year per
household served by the water system.
In the draft report, the cost of using ion
exchange treatment (as described in the
May 1990 draft report) is only $0.91 /
1,000 gallons, or about $90 per year per
household in this size water system,
assuming no need for off-site waste
disposal If off-site waste disposal is
necessary, coots per household might
grow to a'bout $200-$300/yr, still
significantly less than the $l,000/yr
associated with more expensive
engineering assumptions.
EPA recongizes that its May report is
not only a draft, but also only a
preliminary investigation into the actual
costs likely to be incurred by very small
water systems. The report, however,
confirms substantial anecdotal evidence
that EPA's previous small systems costs
may be overestimated in some
circumstances. Aa a result of this
reevaluation of costing assumptions,
EPA concludes that low-cost treatment
trains using the section 1415
technologies could be affordable.
Therefore. EPA finds that all
technologies as listed in tables 28 and 27
are section 1415 BAT.
2. Point-of-Use Devices. Bottled Water
and Pomt-of-Entry Devices
Under section 1415(a) of the SOW A.
when the State grants a variance or
exemption, it must prescribe an
implementation schedule and any
additional control measures that the
system must take. States may require
the use of point-of-use (PQU) devices,
bottled water, and other mitigating
devices as "additional" control
measures if an "unreasonable risk to
health exists." One commenter stated
that EPA should also include point-of-
entry (POE) devices as an additional
option. EPA agrees and has amended
S§ 142.57 and 142.62 in today's rule to
allow POE devices as an interim control
measure while a variance or exemption
is in effect. Public water systems may
also use POE devices for full compliance
with the MCLs if they meet certain
criteria and procedures specified in 40
CFR 8 141.100.
3. Exemptions
Under section 1416(a), a State or EPA
may grant an exemption extending
deadlines for compliance with a
treatment technique or MCL if it finds
that (1) due to compelling factors (which
may inlcude economic factors), the-PWS
is unable to comply with the
requirement (2) the exemption will not
result in an unreasonable risk to human
health; and (3) the system waa in
operation on the effective dale of the
NPDWR. or, for a system not in
operation on that date, no reasonable
alternative source of drinking water is
available to the new system.
In determining whether to grant an
exemption, EPA expects the State to
determine whether the facility codd be
consolidated with another system or
whether an alternative source could be
developed. Another compelling factor is
the affordability of the required
treatments. It is possible that very small
systems may not be able to consolidate
or find a low-cost treatment. EPA
anticipates that States may wish to
consider granting an exemption when
the requisite treatment is not affordable.
EPA believes that, as a rule of thumb,
a total annual household water bill
becomes unaffordable when it is greater
than 2 percent of the median household
income, or about $650/househoki/year,
if calculated based on median national
income. EPA realizes that affordaJbiliry
cannot be characterized by a single
threshold, and believes that in caoes
where local median income is very low,
a total annual household water bill as
small as $450 may be unaffordable. EPA
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Federal Register / VoL 56, No. 20 / Wednesday, January 30, 1991 / Rules and Regulations 3571
believes that any total annual bills
below that amount are affordable.
EPA considered a wide variety of
information when formulating this
unaffordability rule of thumb. Today, the
average annual household water bUl is
about $250. To supplement centrally
treated and piped water with bottled
water costs about $400 more per year, a
cost many people throughout the nation
are willing to pay on an increasingly
frequent basis. This mirrors the market
costs of various POU and POE devices
intended to provide safe drinking water
and which now constitute an active
household products market In addition,
EPA's rule of thumb is similar to that
used by the Department of Agriculture's
Farmers' Home Administration (FmHA)
guidance on the use of grants in place of
loans, based on hardship. Finally, the 2
percent of median income. $850/yr,
value is about equal to the highest
existing annual water bills, although
abnormally high rates (greater than
Sl.OOO/yr) have been documented in a
handful of communities. EPA believes
its rule of thumb reflects both what
many people consider affordable for
high quality water and established
federal policy with regard to enonomic
hardship.
When considering the appropriateness
of an exemption based on affordability,
the States should ensure that a full faith
effort has been made to consider low-
cost solutions similar to those examined
in the May 1990 draft EPA report.
Several commenters also indicated
that affordability considerations should
include all treatments that might need to
be applied by a water system, not
merely those associated with this rule.
EPA agrees with these comments, and
expects States will review all the
treatment requirements of water
systems to add as many treatment
techniques as are affordable. Where the
total treatment need is not affordable,
those treatments should be required that
result in the greatest risk reduction,
while remaining affordable under the
criteria given above.
Under section 1416{b)(2)(B) of the Act
an exemption may be extended or
renewed (in the cases of systems that
serve less than 500 service connections
and that need financial assistance for
the necessary improvements) for one or
more two-year periods. EPA believes
that information on low-cost
technologies will receive a considerable
amount of attention over the next
several years and States giving
exemptions based on affordability
should be prepared to required small
water systems to regularly reexamine
the available technologies to ensure that
any new low-cost opportunities are
applied, where appropriate.
TABLE 26.—SECTION 1415 BAT FOR
INORGANIC COMPOUNDS
Chemical
Asbestos..... ...„____....
Barium ......-.«..««...«..««..«.»»«.»«
Chromium.... H^.M»M.».»....«...
Mercury
Nitrate _....___...
Nitrite ._._„._.._..
BATs
2,3.8
5. 6. 7. 9
2. 5, 6. 7
2, 5. 6 «. 7
2 '. 4. 6 '.
7'
5.7.9
5.7
1.2«. 6. 7.
9
1 BAT only H Influent HG ooneenuaUofis are <10
.
' BAT for Chromium III only.
• BAT tor Selenium IV only.
Key to BA Ts in Table 28
1=Activated Alumina.
2 = Coagulation/Filtration (not BAT for
system* with <500 service connections).
3=Direct and Diatomite Filtration.
4=Granular Activated Carbon.
5=Ion Exchange.
6=Lime Softening (not BAT for systems with
<500 service connections).
7=Reverse Osmosis.
8=Corrosion Control
9=Elec trodialy sis.
TABLE 27.—SECTION 1415 BAT FOR
ORGANIC COMPOUNDS
Chemical name
Benzene ....r--, T--
TrtchtofDetftylene
para PichtofoDeniene
1 2-Dichtofoethylene
1.1,1-Trichkxoethane
Vinyl chloride «
cit 1.x Diclitofoettivlene
Ethylbennne
Oftho Dfchtarobeniene
^turawt*
Tet/acfitafoetnytene
Toluene » ......
trant-l^-OicNorMthyt** —
Xytene* (tout) ..„
Atachtof --,
Aktteart)
Atdictit autfoxide
^affrtffb tuttone
Atrarme
CMonlane
LfluiuiiiumiuiuuiUimie...
?AO
Fthylene dteomkle
Hiptaehkv
Heptacnlor epoxide
yndane
MethoxycMor
PCBt —
Packed
tower
••ration
X
X
X
x
X
X
Granular
activated
carbon
TABLE 27.—SECTION 1415 BAT FOR
ORGANIC COMPOUNDS—Continued
Chemical name
Pentachtoropoenol..
Toxaphene—
2.4,5-TP
Packed
tower
••ration
Granular
activated
caroon
F. Laboratory Certification
Commenters inquired whether EPA
would be utilizing method certification
for laboratory approval or certifying
laboratories for each individual
contaminant EPA recognized this need
and adopted this former system in the
VOC final rule (52 FR (130) 25720. July 6,
1987). Under the performance
requirements for the July 1987 VOC
regulation, laboratories had to pass
certification requirements for six out of
seven VOCs (excluding vinyl chloride).
EPA would like to extend this
philosophy to all its regulated analytes
to reduce the burden on the regulated
community, since it recognizes that even
the best laboratories cannot achieve 100
percent success every time they
participate in performance studies. At
this time, however, only the VOCs have
a large enough group of regulated
analytes to make this method useful.
Today's rule will require laboratories
to pass 80 percent of the regulated
analytes that are present in a
performance sample, including vinyl
chloride, at the current acceptance limits
set for VOCs. The other inorganic and
organic analytes will continue to be
approved at the limits set for them on an
individual basis. When this rule is
effective, 18 VOCs will be analyzed; a
performance sample may include all IB
or only a portion (e.g., 10 VOCs). A
laboratory will have to pass 15 out of 18
or 8 out of 9 to stay certified.
G. Public Notice Requirements
1. General Comments
Three commenters stated that the
notification language is too vague and
alarming. Two commenters thought the
notices may unduly alarm the public
about minor violations or, conversely,
the public may become immune to the
notices when there are serious health
concerns. One of these commenters
stated that the public notification
language should be guidance, and States
should be allowed to determine what
language is appropriate. Another
commenter thought the notifications
should be left to State health officials.
One commenter recommended that EPA
specifically state that water systems can
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3572 Federal Register / Vol. 56, No, 20 / Wednesday, January 30. 1991 / Rules and Regulations
append the notification to include
information on the nature, seventy and
context of potential health effects, aa
well aa other useful information. One
commenter stated that more detail and
explanation is needed to- define "little or
no risk," which is the generic conclusion
of each notification. This commenter
suggested that more of the risk
fltt«pflBTtiont assumptions- be- included
(e.g., lifetime consumption of 2 liters per
day with a x-fold safety factor). One
commenter similarly felt some
indication that a margin, of safety is used
to establish MCLs is needed.
EPA Response. EPA believes- the
public notification language is
sufficiently detailed for the public and
should not be unnecessarily alarming.
Some language has been modified based
on the chemical-specific comments that
were received.
EPA believes that mandatory
language it the most appropriate (if not
the only) way to inform the affected
public Of the health frnpliryitinny of
violating a particular EPA standard. It i»
' appropriate for EPA to specify the
language kfctmmr th»» Agamy in fimdHar
with the specific health, implications of
violating each standard which were
documented in the contra of developing
the NPDWRs. EPA is aware that the
health implications of these violations of
vary in their magnitude. Public water
systems are free to make that point in
their public notices aa long a» the
mandatory language is- included as-welL
For instance, the system may want to
note that its violation i» only slightly
above the standard. In fact, the public
water system or State may supplement
the notice as long as. the notice inform*
the public of the health risks-which EPA
has associated with violation of. the
standards and the mandatory health
effects language remains, intact.
EPA believes the piihlir n»tifimtif>nT
should be in non-technical terms.
Providing the specific risk assessment
assumptions or discussing the margin of
safety would be too detailed and raise
confusion.
2. Contaminant-Specific Comments
a. Asbestos. Four commeoten stated
that the language for asbestos-should
not state that the standard is based on
reducing cancer risks, i?'™^* asfasates is
not a carcinogen. Two commentem
asked that the statement be revised to
separate the insulating and fire
retardant uses from A/C pipe urea. One
commenter suggested the following
modification for asbestos^ "fagestioa of
asbestos is associated with polype
(benign tumors) in rats."
EPA Beapoau. EPA agceee- wHb moat
of the comments received on aebactoo
and has modified the public notification
language accordingly. The standard for
asbestos is based on reducing possible
human cancer risks, from drinking water
exposure.
b. Other Contaminants. One
commenter stated that the language for
selenium should be revised to explain
the nutritional essentiality of selenium.
One commenter stated that the nitrate
language should state that alternate
water sources should be provided to
children under one year of age. One
commenter recommended modified
wording for stymie*. One commenter'
agreed with the notification language for
alachlcr and monochlorobenzene. One
commenter r»«-jM« mended the following
replacement wording foz pesticides:
"Under certain soil and climatic
conditions (e.g., sendy soil and high
rainfall), substance 'X1 may leach into
ground water efter normal agricultural
applications or may enter drinking
water supplies as a result of surface
runoff." One commenter believes the
statement concerning liver and kidney
effects from atrazine is an error. This
same commenter provided suggested
changes for 20 chemicals. One
commenter believes
language, "Smoking of tobacco is a
common source of general exposure,"' is*
inappropriate; this commenter believes
(hat the notifications should only
include information on occurrence or
exposure from drinking water. This
same commenter believes the language
for the polymers. acrylamide and
epkhlorohydrin is too alarming
considering the minimal risk. Another
commenter suggested changes for the
acrylamide notice.
EPA Response. EPA believe* that the
current language stating the nutritional
essentiality of selenium is sufficient
Consumers may obtain additional
information concerning essentiality from
the appropriate State regulatory agency.
For nitrate/nitrite, EPA agrees that the
age should be specified. However. EPA
disagrees with an age of one year aa aU
data suggest that infants un^1"1 the age
of six months are the sensitive
population. EPA has modified the notice
accordingly.
EPA agrees with most of me
comments received on stymie and with
the proposed generic changes for
pesticides and has modified the public
notification accordingly.
EPA also agrees that the etraznw
language should better reflect the study
used to derive the MCLG, and the public
notification language has been modified
accordingly.
EPA believes the potential risks from
misuse of acrylamide and
epichlorohydrin are properly qualified IB
the proposed public notification
language, and therefore should not
result in under public alarm.
EPA has considered other chemical-
specific changes and has modified the
language in some cases (see the
Comment/Response Document for
detailed response to comments).
H. Secondary MCLa
EPA proposed secondary maximum
contaminant levels (SMCLs) based on
taste and odor detection levels for seven
organic chemicals (o-dichlorobenrene.
p-dichlorobenzene. ethylbenzene,
pentachlorophenoi, styrene, xyfene, and
toluene) and for silver and aluminum.
These organic chemicals had reported
taste or odor detection levels lower than
the proposed (or final] MCLs. EPA
believed it appropriate to set SMCLs for
these compounds to protect against
aesthetic effects (such as odor) which;
could be present at levels below the
proposed MCLs.
1. Organic*
After reviewing the public comments,
EPA has decided to defer promulgating
SMCLs for the seven organic chemicals
for the following reasons:
A number of commenters opposed
SMCLs for the seven organic* due to an
inadequate-experimental basis for
setting SMCLs for ethylbenzene,
styrene, toluene, andxylene. While the
literature citation used for these
chemicals (Amoore and Hautala, 1983]
was based on theoretical extrapolation
(from air odor thresholds) end while it
appeared to provide valid levels, it was
not confirmed in any published
literature.
The experimental identification of any
chemical concentration in drinking
water with a perceived aesthetic effect
presents a difficult and currently
unresolved task. Minimum- detection
levels, although different in different
waters, might be identified but the point
of consumer complaint for each
chemical, in different waters, would
require more study and research.
EPA is none the less convinced that
taste and odor problems represent a
significant continuing and unresolved
problem for drinking water suppliers
and their consumers. Accordingly, EPA
may initiate a "National Task Force of
Experts" to review and assess the data,
information, and opinions available with
respect to taste and odor-problems in
public water supplies including problem
definition, possible SMCL and analytical
options available, and means for
implementing solutions. If initiated, the
task force would develop one or more
SMCL approaches- with- developed
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Federal Register / Vol. 56. No. 20 / Wednesday. January 30, 1991 / Rules and Regulations 3573
analytical technology for possible
adoption in a proposed future secondary
regulation amendment. The task force
may also provide supplementary
guidance relating to detectable and
aesthetically displeasing levels for
specific organic chemicals.
EPA wishes to alert the States.
utilities, and consumers that it is
retaining the existing odor SMCL of 3
Total Odor Number (TON) (see 40 CFR
143.3). Utilities are urged to find
imaginative ways to meet the objective
of having more pleasing odor
characteristics for their finished water
using the current 3 TON standard.
Where officials and consumers find
contaminated drinking waters, they may
expect to detect (possibly slight) tastes
or odors at the concentrations indicated
below:
o-Dichlorobenzene 0.01 mg/1.
p-Dichlorobenzene 0.005 mg/1,
Ethylbenzene 0.03 mg/1,
Pentachlorophenol 0.03 mg/1,
Styrene 0.01 mg/1,
Toluene 0.04 mg/1,
Xylene 0.02 mg/1.
2. Aluminum
A total of 17 individuals or
organizations provided comments in
response to the proposed SMCL of 0.05
mg/1 for aluminum. All of these
commenters agreed that the proposed
SMCL is too low and should either be
increased or eliminated.
Pertinent points from the comments
are summarized as follows:
• The American Water Works
Association (AWWA) no longer backs
the quality goal of 0.05 mg/1 which it
initially adopted on January 28,1068 but
does support a "recommended operating
level of 0.2 mg/1."
• The proposed SMCL of 0.05 mg/1
would be very difficult for many utilities
to meet; a 1987 AWWA/Research
Foundation Survey of 90+ utilities
indicated an average aluminum
concentration of 0.09 mg/1 in finished
water. Individual utilities also expressed
concern with difficulty in meeting the
0.05 mg/1 SMCL
• There is insufficient experimental
data to define the level at which an
aesthetic effect might occur in various
waters and treatments.
EPA believes that in some waters
post-precipitation of aluminum may take
place after treatment. This could cause
increased turbidity and aluminum water
quality slugs under certain treatment
and distribution changes. EPA also
agrees with the World Health
Organization (WHO, 1984) that
"discoloration of drinking water in
distribution systems may occur when
the aluminum level exceeds 0.1 mg/1 in
the finished water." WHO further
adopts a guidance level of 0.2 mg/1 in
recognition of difficulty in meeting the
lower level in some situations. While
EPA encourages utilities to meet a level
of 0.05 mg/1 where possible, it still
believes that varying water quality and
treatment situations necessitate a
flexible approach to establish the SMCL.
What may be appropriate in one case
may not be appropriate in another.
Hence, a range for the standard is
appropriate. The definition of
"secondary drinking water regulation"
in the SDWA provides that variations
may be allowed according to "other
circumstances." The State primacy
agency may make a decision on the
appropriate level for each utility on a
case-by-case basis. Consequently, for
the reasons given above, the final SMCL
for aluminum will be a range of 0.05 mg/
1 to 0.2 mg/1. with the precise level then
being determined by the State for each
system.
3. Silver
On May 22.1989. EPA proposed to
delete the current MCL for silver (Ag),
because the only potential adverse
effect from exposure to silver in drinking
water is argyria (a discoloration of the
skin). EPA considers argyria a cosmetic
effect since it does not impair body
function. Also, silver is seldom found at
significant levels in water supplies and
drinking water has never been identified
as the cause of argyria in the United
States. While the health effects of silver
may only be cosmetic, many home
water treatment devices use silver as an
antibacterial agent. These devices may
present a potential contamination threat
when used in a system. Therefore. EPA
proposed (54 FR 22062) an SMCL for
silver at 0.09 mg/1 based on the skin
cosmetic effect called argyria. EPA also
asked the public to comment on the
selection of an uncertainty factor (UF) in
the alternate calculation of SMCL.
assuming an oral absorption factor of 4
percent.
Public Comments. A total of six
individuals or organizations provided
comments in response to the proposed
rule regarding silver. All commenters
agreed that the MCL for silver (0.05 mg/
1) should be deleted. Several
comrr.er.ters agreed with EPA's proposal
of an SMCL for silver. Other
commenters disagreed with this
proposal, citing the following reasons for
support:
• Silver does not affect the taste,
odor, color, or appearance of the
drinking water.
• There is no evidence that the low
level of silver that might be found in
drinking water causes argyria in
humans.
In response to a specific question
posed in the Federal Register Notice on
the selection of a UF for the alternate
calculations of the SMCL. different
opinions were expressed. Several
commenters suggested using an
uncertainty factor of 2 in support cf 25
mg/1), while one proposed to keep the
SMCL at the current MCL of 0.05 mg/1.
EPA Response. EPA has decided a
SMCL of 0.1 mg/1 is needed to protect
the general public from the cosmetic
effect of arcyuria (from lifetime
exposure to silver). While the health
effects of silver may only be cosmetic.
many home water treatment devices use
silver as an antibacterial agent, thus
presenting a potential contamination
threat when such devices are used in a
system. Therefore, EPA has decided to
keep the SMCL at 0.1 mg/1 to protect the
welfare of the general public from the
cosmetic effect of argyria.
EPA is proposing to use the same data
base as before-to calculate the SMCL for
silver. Assuming 1 g of silver by i.v. will
cause argyria in the most sensitive
individuals (Gaul and Staud. Am. Med.
Assoc. 104:1387-1390.1935; Hill and
Pillsbury, 1939) and assuming an oral
absorption rate of 4 percent (Fuchner et
al., Health Physics 15:505-514.1968). a
lifetime exposure of 70 years, and a UF
of 3. an SMCL of 0.1 mg/1 is derived. For
more detail, see the following derivation
of SMCL
a. Derivation of SMCL for Silver. The
cosmetic DWEL is calculated assuming
1 g of silver administered i.v. will
produce a mild argyria in the most
sensitive individuals (Gaul and Staud.
1935; Hill and Pillsbury. 1939). Assuming
4 percent absorption of silver (Furchner
et al., 1968) following oral exposure, the
i.v. dose corresponds to an oral dose of
25 g (1 g/0.04=25 g). This dose is then
averaged over a lifetime assumed to be
70 years:
25 gx
lifetime
25.550 days
= 978 us/day
Based on an adult body weight of 70
kg, this corresponds to 14 fig kg/day
(978 ng/day / 70 kg=14 fig/kg/day).
Step 1—Cosmetic RfD Derivation
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3374 Federal Register / Vol. 56, No. 20 / Wednesday, January 30. 1991 / Rules and .Regulations
Cosmetic
K:D
14 us Ag/
kg/day _ 4.7 fig Ag/
kg/day
wnere:
14 ^g Ag/kg/day=Lowasi Observed
Cosmetic Effect Level based on argyria.
3=uncertainty factor.
An uncertainty factor of 3 was applied
for the following reasons. First, a ID-fold
uncertainty fact or IB usually applied to
human data to account for intraapecies
variability. However, since this
derivation has already included
sensitive individuals, a 10-fold
uncertainty factor ia not warranted.
Second, an uncertainty factor leas than
10 (i.e., 3) is flufficieatly protective since
the estimated dose causing argyria
within one to three yean is being
apportioned over a lifetime. Finally, the
effect is based on argyria, which is
considered a cosmetic effect, and not an
adverse health effect.
Step 2-*Cosmetic DIVEL Derivation
Cosmetic DWEL
4.7MAg/kg/
day x 70 kg
2 I/day
•= 104 fig/1 {Bounded to 200 pg/lj
where:
4.7 ng Ag/kg/day «= Connetic RfD.
70 kg = assumed body weight of an adult
2 I/day = assumed-wroter-consumption by an
adult.
The Cosmetic DWEL is derived on the
assumption that 100 percent cf the silver
intake comes from drinking water. As
estimated by the World Heath
Organization (WHO, I960), the upper
bound of intake level for silver from
food is 20 to 80 fig .per day; from air it is
essentially negligible. Therefore, the
SMCL for the cosmetic effect of silver
can be calculated by subtracting the
amount obtained in food.
Step 3—SMCL
SMCL -
[0.0047 ing/kg/
day) (70 kg) - 0.1)8
mg/day
?I/day
= 0.12 mg/1 (rounded to 0.1 n-.g/l or 100 us/
1)
/ State Implementation
The Safe Drinking Water Act provides
that States may assume primary
implementation and enforcement
responsibilities. Fifty-four out of 57
jurisdictions have applied for and
received primary enforcement
responsibility (primacy) under the Act.
To implement the federal regulations for
drinking water contaminants, States
must adopt their own regulations which
are at least as stringent as the federal
regulations. This section of today's rule
describes the regulations and other
procedures and policies the States must
adopt to implement today's rule. EPA
previously promulgated program
implementation requirements in 40 CFR
part 142 on December 20,1889 (54 FR
52128).
To implement today's rule, States will
be required to adopt the following
regulatory requiremarts when they are
promulgated: § 141-23, Inorganic
Chemical Sampling and Analytical
Requirements; g 141.24, Organic
Chemical Other Than Total
Trihalomethanes Sampling and
Analytical Requirements; (141.32.
General Public Notice .Requirements
(Le, mandatory teal th effects language
to be indoded in public notification or
violations); j 141.40, Special Monitoring
for Inorganic and Organic Chemicals;
§ 141.61 (a) and (c). Maximum
Contaminant Levels for Inorganic and
Organic Chemicals; and 9 141.111,
Treatment Techniques for Acrylamide
and Epichlorohydrin.
In addition to adopting drinking water
regulations no less stringent than the
federal regulations listed above, EPA is
requiring that States adopt certain
requirements related to this regulation in
order to have their program revision
application approved by EPA. In various
respects, the proposed NPDWRe provide
flexibility to the State with regard to
implementation of the monitoring
requirements under this rule. Because
State determinations regarding
vulnerability and monitoring frequency
will have .a substantial impact with
implementation of this regulation, the
proposed rule requires States to submit
as part of their State program
submissions their policies and
procedures in these areas. This
requirement will serve to inform the
regulated community of State
requirements and alsc help EPA in its
oversight of State programs. These
requirements are discussed below under
the section or special primacy
requirements. Today, EPA is also
promulgating changes to State
record-keeping and reporting
requirements.
1. Special State Primacy Requirements
To ensure that the State program
includes all the elements necessary for
an effective and enforceable program,
the State's request for approval must
contain the following: (1) If the Stale
issues waivers, the procedures and/or
policies the State -will use to conduct
and/or evaluate vulnerability
assessments; (2) the procedures/policies
the State will use to allow a system to
decrease its monitoring frequency; and
(3) a plan that ensures that each system
monitors by the end of each compliance
period.
In general, commenters supported the
proposed primacy requirements.
However, one comcKnter characterized
the provisions as "resource
constraining," "confusing," "redundant,
"cumbersome," and "not necessary."
Several ccmmenters were concerned
about the resource impact of
vulnerability assessments on State
programs. Several States desired
sufficient flexibility to tailor monitoring
requirements to site-specific conditions.
Another commenler urged the Agency to
allow "area wide" or geographic
vulnerability determinations.
EPA has made several changes to
address the commenters' concerna. First,
as described elsewhere in today'* rule,
EPA has adopted a standard monitoring
framework which synchronizes
monitoring schedules end standardizes
monitoring requirements. These changes
should reduce the confusion and
redundancy cited fay one cnmmenter.
One of the changes £PA is promulgating,
which is described in the jection on
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Federal Register / Vol. 56, No. 20 / Wednesday. January 30, 1991 / Rules and Regulations 3575
monitoring, is shifting the responsibility
for conducting vulnerability
assessments from the State to the
system. The State retains, however, the
responsibility to approve the results of
vulnerability assessments and to issue
waivers. EPA believes that this change.
in part addresses the resource
constraint issue cited by the
commenters. States, by implementing
the standard monitoring framework and
by issuing waivers, will be able to tailor
monitoring requirements to site-specific
conditions in most cases. EPA will allow
States to issue "geographic" or "area
wide" waivers. This change is also
described in the section on monitoring.
The special primacy requirements
have been revised to establish criteria
for State descriptions of the waiver
programs the State will administer. EPA
will develop detailed guidance for use
by Regional Administrators in reviewing
primary applications, and in
administering this rule in non-primacy
States. As insurance against State
'abuse of discretion' in reducing
individual sampling frequency
requirements. EPA added § 142.16(f) to
establish authority for federal rescission
of State waivers that do not meet the
criteria established in §5 141.23.141.24.
and 141.40.
To encourage careful planning of the
framework's implementation. EPA has
added a special primacy provision in
today's rule that requires the
development of State monitoring plans
that are enforceable under State law.
EPA is making this change to ensure
that all water systems complete
monitoring (or conduct a vulnerability
assessment) by the end of each three-
year compliance period. In general,
State monitoring plans should require
approximately one-third of the systems
to monitor each year during each three-
year compliance period to provide for an
even flow of samples through State-
certified laboratories. States will be able
to establish their own criteria to
schedule the systems to monitor. If a
State does not have primacy for today's
provision at the time the initial
compliance period begins (i.e.. January
1.1893), then EPA will be the primacy
agent Because water systems may be
confused as to when each system must
monitor. EPA has established
procedures (5 S 141.23(k). 141.24(f)(23).
and 14I.24(h)(18)) that require systems
to monitor at the time designated by the
State. If EPA implements today's
provisions because a State has not yet
adopted the regulatory requirements in
today's rule. EPA intends to use the
State's mom coring schedule to schedule
systems during each compliance period.
EPA believes this approach will reduce
confusion over when each system
monitors once the State adopts today's
requirements.
2. State Recordkeeping Requirements
In 55 141.16(d)(ll) through
142.16(d)(16), EPA proposed that States
would maintain records of: (1) Each
vulnerability determination and its
basis; (2) each approval of reduced
monitoring and its basis; (3) each
determination that a system must
perform repeat monitoring for asbestos
and its basis; (4) each decision that a
system must monitor unregulated
contaminants; (5) each letter from a
system serving fewer than 150 service
connections that it is available for
monitoring of unregulated contaminants;
and (8) annual certifications that
acrylamide and epichlorohydrin are
used within Federal limits for the
combination of dose and monomer
levels. EPA also requested comment on
whether the existing record retention
requirement of 40 years is reasonable, or
should be modified.
In general, commenters (mostly
States) characterized the proposed
recordkeeping requirements as
"absurd," "terrible," "excessively
burdensome," and "unwarranted." The
most substantive comments are listed
below. EPA has revised this part to
conform to the standard monitoring
framework, and to provide auditable
records during Federal oversight
reviews.
One commenter said that the unduly
diverse and complex sampling periods
will exacerbate the complexity of the
record/file systems. In response, the
Agency notes that the sampling periods
have been consolidated into the
Standard Monitoring Framework, in
order to simplify the program
requirements for local. State, and
federal personnel. This framework
consists of repeating three-year
compliance periods within repeating
nine-year compliance cycles.
Another commenter stated that
maintaining documentation of
assessments resulting in non-vulnerable
status or reduced sampling frequencies
is less important than addressing CWSs
with real problems. System by system
documentation of vulnerability
assessments is unnecessary; State
summaries of each assessment should
suffice. Many States either have
inadequate resources to manage
complex record systems, or will have to
divert resources from more important
activities, such as technical assistance
for small communities.
In response. EPA does not disagree
with the commenter's priorities, but the
Agency also believes that a precise
record of each decision affecting public
health is necessary. The commenter
should note that States are not required
to conduct vulnerability assessments.
and States may reduce the resource
impact of these regulations by applying
uniform monitoring requirements to all
CWSs. However, if vulnerability
assessments are used as the basis for
granting waivers from the uniform
monitoring requirements, there must be
complete documentation of those
assessments and the basis for each
decision. In the final rule, EPA has
clarified that records of only the most
recent assessment and monitoring
frequency determination need be
maintained.
One commenter stated that since
authority to enter and inspect is a
primacy requirement under
§ 142.10(b)(6)(iii), the requirement for
records of sampling availability letters,
and the letters themselves, is
superfluous. In response, EPA agrees
with this comment, and has deleted the
State recordkeeping requirement of
systems which serve less than 150
service connections which send letters
of availability.
Another comment asserted that
annual certifications of proper
acrylamide and epichlorohydrin
applications are unnecessary; the
application requirements should be
sufficient
In response, EPA believes the
requirement is a reasonable means of
attempting to confirm proper application
of these chemicals, considering that the
minimum frequency for sanitary surveys
is five years.
Another commenter pointed out that
the 40-year record retention requirement
is an unreasonable burden on State
resources.
In response, EPA has reduced the
standard monitoring records retention
requirement to 12 years. This covers a
nine-year monitoring cycle plus a three-
year monitoring period, to allow time for
more current records to replace older
records.
3. State Reporting Requirements
In 55 142.15(a)(12) through
142.15(a)(17). EPA proposed that States
would report lists of: (1) Systems for
which vulnerability assessments have
been conducted, the assessment results.
and their bases; (2) systems that have
been permitted to reduce their
monitoring frequencies, the bases for the
reduction, and the new frequencies; (3)
systems that must conduct repeat
monitoring for asbestos: (4} systems
serving fewer than 150 service
-------
3578 Federal Register / Vol. 56, No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
connections that have notified the State
of their availability for campling of
unregulated contaminants; and (S)
systems that have certified compliance
with treatment requirements for
acrylamide and epichlorohydrin. EPA
also proposed that States report the
results of monitoring for unregulated
contaminants.
Generally, commenters characterized
the proposed rule as "redundant,"
"useless." "onerous," "excessive,"
"burdensome," "unnecessary," and
"inconsistent with other reporting
requirements."
In addition, many comments raised
the following points:
• The appropriate vehicles for EPA
oversight are review of primacy
applications and annual en-site program
management audits.
• The proposed reporting
requirements are redundant to those
activities and therefore inappropriate.
• EPA's need for, or prospective use
of, the data to be reported is unclear.
• Reporting should be standardized
with other rules, and conducted through
a computerized data base.
In response, EPA agrees with these
points after reviewing the Agency's
information needs. EPA has determined
that the core reporting requirements of
the Primacy Role, December 20,1989,
are sufficient for purposes of routine
program oversight Therefore, the
Agency has deleted the proposed
reporting requirements, except for the
requirement to report results of
monitoring for unregulated
contaminants in 1142.15(a}(15). These
results are needed for development of
future MCLs.
IV. Economic Analysis
Executive Order 12291 require? EPA
and other regulatory agencies to perform
a Regulatory Impact Analysis (R1A) for
all "major" regulations, which are
defiend as those regulations which
impose an annual cost to the economy
of $100 million or more, or meet other
criteria. The Agency has determined
that this action constitutes a "major"
regulatory action for the purposes of the
Executive Order. Therefore, in
accordance with the Executive Order,
the Agency has conducted an
assessment of the benefits and costs of
both the proposed and final rules.
The RIAs supporting die proposed
rule (see "Regulatory Impact Analysis of
Proposed Inorganic Chemical
Regulations," March 31,19S9, and
"Regulatory Impact Analysis of
Proposed Synthetic Organic Chemical
Regulation*," April 1989) estimated an
incremental annualized cost to the
nation of $42 million for treatment and
waste disposal. Monitoring costs for the
proposed rule were estimated to be
about $29 million/year incrementally.
Thus, the total incremental annualized
cost to the nation of the proposed
requirements was about $71 million/
year. In addition, unregulated
contaminants were estimated to result
in a one-time cost of $42 million.
In response to public comments and
receipt of new data or information, EPA
made several changes to the proposed
rule which resulted in an overall
increase in the projected compliance
costs for the final rule. In addition.
revised unit cost and occurrence data
were incorporated into the final RIAs.
These changes, and their corresponding
effects on the original cost estimates are
described below. The cost of compliance
for aldicarb, aldicarb sulfoxide, aldicarb
sulfone, barium and pentachlorophenol
continue to be included in the R1A
supporting today's rule.
A. Cost of Final Rule
Table 28 shows the results of the
Regulatory Impact Analyses which
support today's final rule. MCLs
promulgated in today's rule for barium.
chromium, and selenium are all less
stringent than existing National Interim
Primary Drinking Water Regulations
(NIPDWR). As a result, the incremental
annualized treatment and waste
disposal cost of $84 million/year are
associated with the more stringent
MCLs for cadmium and the SOCs which
are promulgated in today's final rule.
Incremental monitoring costs are
estimated to be about $24 million/year.
Thus, the incremental annualized
compliance cost to the nation of about
$88 million/year is somewhat higher
than the $71 million/year eotimated for
the proposed rule. In addition,
unregulated contaminants are expected
to result in a one-time cost of $39
million, wliich is lower than the $42
million estimated for the proposal.
Approximately 3,242 community and
non-transient non-community water
systems are not currently in compliance
with existing NIPDWRs and would not
be in compliance with this rule either.
As a result, these systems will incur
compliance costs associated with
enforcement of today's rule. The cost of
these 3,242 systems to come into
compliance would be $666 million per
year for treatment and waste disposal
and $1.5 million per year for monitoring.
TABLE 28.—SUMMARY ESTIMATES FOR
FINAL IOC AND SOC REGULATIONS
Systems in Violation ..
Costs (m/IHons/yr):
Compliance Costs ....
— Monitoring
—Treatment end
Weae
Dbpoeal Costs
at 3%
Unregulated
Contamnant
Cost*&f) .
State
Implementation
Costs Initial ($M) .
Outreo (SM/yr)
Swwfatt
Population WUh
Reduced
Exposure
(rnRwons) »..H...M«»
Ccncer Cflfffff _«»«..
see
ettmatss
'3.110
STB
21
•57
••»•••«•.
2.7
72
IOC
estimates
165
$10
2.5
7.0
,»..., M.-.i.n.
0.2
Total
3.265
see
24
64
39
21
17
2.9
72
1 Includes en estimated 825 systems which will
violate tne proposed MCL for pantachlorophenol.
•Includes $19 mjHton to treat for pwitachtoro-
phenot. which to DUIQ roproposed cisewhefe tjd&y
In the Federal Register.
Table 28 also shows the benefits of
today's final rule. Compliance with the
IOCs MCLs is expected to provide .
reduced exposure to almost 200.000
people resulting from lowering the MCL
for cadmium. The types of health effects
expected to be avoided include chronic
toxic effects such as kidney toxicity.
Compliance with the SOCs MCLs is
expected to provide reduced exposure to
almost three million people and prevent
about 72 cases of cancer per year.
B. Comparison to Proposed Rule
Table 29 compares the costs and
benefits of today's final rule to those
estimated for the proposal. The
differences in the cost estimates are
attributable to a variety of changes in
the rule and in the available input data
used in the analyses. Among the more
influential changes are the following:
1. Monitoring Requirements
As described in section iil(D) of
today's preamble, the monitoring
requirements in today's rule are
somewhat different from those included
in the proposed rule. A direct
comparison between the monitoring
costs estimated in the proposal and
those estimated for the final rule is not
entirely appropriate because the costs
estimated for the proposal were
aggregated over nine years, whereas the
costs for the final rule are aggregated
over 18 years.
-------
Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3577
TABLE 29.—COMPARISON OF COSTS FOR
PROPOSED AND FINAL RULES
Proposed
rule
Rule: •
Number of Systems _..
Capital Costs ($M)
Annualizad Capital Costs (SM/
YR)
Operation a Maintenance Costs I
(SM/YH) I
Monitoring Costs (SM/YH) j
Total Annus'-zed Costs (SM/YR)..
Unregulated Contaminant MOTH- !
tonng (SM) _ j
Siate Implementation Costs:
Initial (SM) ;
Out-yen: (SM/YR) I
T
2.475
$361
24
18
29
71
42;
24
14
Final
3,275
$554
37
27
24
88
39
21
17
' Includes pentachlorophenol. which is repro-
pojea.
Table 29 shows that the monitoring
costs for the final rule are somewhat
less than the monitoring costs estimated
for the proposal. This decrease is
primarily due to a reduced number of
systems which are expected to be
vulnerable to SOC contamination.
Current VOC monitoring cost estimates
are expected to be higher than those
estimated for the proposal for the
following reasons:
• Systems are phased in more quickly
in the final rule. Thus, systems
previously expected to monitor only
once every nine years are now expected
to monitor for VOCs three times during
an 18 year cycle: and
• The final rule requires ail
vulnerable systems to incur VOC
monitoring costs once/year, whereas the
proposal requires systems serving fewer
than 3,300 people to incur monitoring
costs only once during the nine year
cycle and larger systems only incur
monitoring costs twice during the nine
year cycle.
2. Changes in MCLs
Although several MCLs in the final
rule have changed from those that were
proposed (e.g., toluene, toxaphene), only
the proposed MCL for
pentachlorophenol is more stringent as
to result in additional impacts. The
reproposed MCL for pentachlorophenol
is 0.001 mg/1. compared to the proposed
standard of 0.2 mg/1.
3. Changes in Occurrence Data
Occurrence data used in the final
Phase II RIAs have been changed to
include the following:
• Revisions to the NIRS groundwater
occurrence estimates for barium,
cadmium, chromium, mercury and
selenium: and
" Additional occurrence data on
pentachlorophenol provided by AWWA
resulted in estimating 825 systems
would exceed the proposed MCL of
0.001 mg/1.
4. Changes in Unit Treatment Cost
Estimates
Changes in system design flow
assumptions resulted in revised
treatment and waste disposal unit cost
estimates for both lOCs and SOCs.
The combined effects of these changes
are lower national treatment and waste
disposal costs for lOCs, but higher
national treatment and waste disposal
costs for SOCs. The revised design flow
assumptions directly resulted in higher
household annual costs for both lOCs
and SOCs.
C. Cost to Systems
Table 30 suggests that the cost
impacts on water systems and
consumers affected by most of the
synthetic organic and inorganic
contaminants are small and vary
depending upon the specific chemical
contaminant and the size of the public
water system. Households served by
serving more than 3,300 people could be
subject to water bill increases of
between $5 and S205 per year, if their
systems have SOC or IOC
contamination greater than the MCLs.
EPA believes that these costs are
affordable.
TABLE 30.—UPPER BOUND HOUSEHOLD
COSTS (S/HH/YEAR)
System size (population served)
25-100
101-500 . . ~
3.300-10,000
25.000-50.000 _ - —
over 1 ,000.000.-
SOCs1
S598
233
64
42
31
K30«
$696
442
122
167
205
1 Granular Activated Carbon or Packed Tower Aer-
ation.
* Weighted average based on probabilities associ-
ated with alternative treatments (i.e.. conventional,
kme softening, ion exchange, reverse osmosis, acti-
vated alumina, activated carbon and others).
Smell systems, those serving fewer
than 500 people, incur higher per
household costs because they do not
benefit from engineering economies of
scale. Households served by these small
systems would have to pay significantly
more, should their system have SOC or
IOC contamination greater than the
proposed MCL In the case of SOCs,
typical annual water bills could increase
by as much as $598. which EPA believes
may not be affordable. In the case of
lOCs, water bills in small supplies could
climb an additional $896 per year in
contaminated systems.
D. Cost to State Programs
In 1963 EPA and the Association of
State Drinking Water Administrators
(ASDWA) conducted a survey of State
primacy program resource needs for
implementing the 1988 SDWA
amendments. The State implementation
costs for the proposal were estimated to
be about $14 million per year, after an
initial cost of $24 million. The survey
results have since been updated to
include additional respondents. Thus.
the revised State implementation costs
for today's final rule is estimated to be
about $21 million initially and $17
million/year in the out-years.
Over half of the initial and out-yea:
costs are expected to be associated with
expanding laboratory capabilities for
analyzing samples. After laboratory
expansion, development of vulnerability
criteria, revising Slate primacy
agreements, training staff on the rules,
modifying the data management system,
educating the public on the rules, and
formal enforcement of the rules are each
expected to require about one million
dollars initially to be implemented. With
respect to out-year costs, formal
enforcement and public education are
expected to require the most resources
after laboratory expansion costs.
The State survey results for the Phase
II requirements are based on the
proposal; however, the survey
questionnaire was carefully reviewed to
determine if the estimated costs should
be revised. This review indicated that
the estimated State implementation
costs for the proposal should not be
significantly different from those
expected for the final rule.
V. Other Requirements
A. Regulatory Flexibility Analysis
The Regulatory Flexibility Act (RFA)
requires EPA to consider the effect of
regulations on small entities [5 U.S.C.
602 et seq.}. If there is a significant effect
on a substantial number of small
systems, the Agency must prepare a
RFA describing significant alternatives
that would minimize the impact on small
entities. The Agency had determined
that the proposed rule, if promulgated.
would not have a significant effect on a
substantial number of small entities.
The RFA for the final rule indicates
that of 199,390 community and non-
cornrnunity water supplies serving fewer
than 50.000 people, about 6,473 (3.2%)
are estimated to exceed the final MCLs
promulgated in today's rule. Compliance
costs estimated for the 6,473 systems
required to install treatment are about
$313 million per year. Because of the
nitrates monitoring requirements, all
199,390 systems are estimated to comply
with the monitoring requirements. The
monitoring costs for these small systems
-------
/ Vol. 58. No. 20 / Wednesday, January 30. 1B31 / Rules and Regulations
ara estimated to be about S4 million/
year for lOCs and about $20 million/
yecr for SOCs. Baaed on the RFA
results. EPA has determined that the
6.473 systems required to install
treatment will be significantly affected
by this rule.
While a "substantial" number of the
small water supplies serving fewer than
50.000 persons will be affected by the
monitoring requirements, their
production costs will not increase by
five percent. Therefore, the impact on
this substantial number of systems is
not considered "significant" according
to RFA guidelines. There are 6,473 small
systems estimated to require treatment
and thus, incur "significant" increases in
costs. However, 6,473 systems is only
3.2% of 199,390 systems and. according
to EPA guicslinss for conducting RFAs,
less than 20% of a regulated population
is not considered a substantial number.
Despite the results of this RFA, the
Agency considers several thousand
syotems to be substantial and has
attempted to provide greater flexibility
to small systems while etill providing
adequate protection of the public health.
The most significant change to the
proposed rule which reduces the burden
on small systems involves standardized
monitoring requirements and the
opportunity for waivers. In addition,
EPA has reduced some monitoring
requirements for systems serving < 3,300
people.
As well as these changes in the rule,
the 1988 Amendments to the SDWA
provide small systems with exemptions.
Thus, the Agency has tried to relieve
small systems as much as possible from
the costs of compliance with the
regulatory requirements while still
providing adequate protection to the
health of their consumers.
B. Paperwork Reduction Act
The information collection
requirements in this rule have been
Eubmitted for approval to the Office of
Management and Budget (OMB) under
the Paperwork Reduction Act [44 U.S.C.
3501 et seq.}. An Information Collection
Request (ICR) document has been
prepared by EPA and a copy may be
obtained from: Sandy Farmer,
Information Policy Branch. EPA. 401 M
Street, SW. (PM-223). Washington. DC
or by calling 202-332-2740.
Public reporting burden for today's
final rule is estimated to average 0.7
hours per response. The entire regulated
population of 200,133 systems will incur
some monitoring costs for nitrates. Of
She total population, 78,703 systems are
expected to incur monitoring costs for
contaminants other than nitrates. The
total burden estimate is about 3.2
million hours per year. In addition.
systems monitoring for unregulated
contaminants are expected tc incur a
one-time reporting burden of 0.5 hours/
response resulting in a total of 31.481
hours. The monitoring costs associated
with these information collection
requirements are somewhat lower than
those estimated for the proposed rule.
Specifically, IOC monitoring costs have
increased from §4 million/year to §4.5
million/year. SOC monitoring costs
have decreased from S27 million/year to
$21 million /year, and the one-time
monitoring costs for unregulated
contaminants have decreased from £42
million to $39 million. The change in cost
is due to the numerous changes made to
the monitoring, recordkeeping, and
reporting requirements that had been
proposed. The information collection
requirements are not effective until
OMB approves them and a technical
amendment to that effect io published in
the Federal Register.
VI. Public Docket and Rafefimoso
All supporting materials pertinent to
the promulgation of this rale are
included in the Public Docket located at
EPA headquarters, Washington. DC. The
Public Docket is available for viewing
by appointment by calling the telephone
number at the beginning of this notice.
All public comments received on the
1985 proposal are included in the
Docket.
All references cited in this notice are
included in the Public Docket together
with other correspondence and
informetion.
Las! of Subjects w flffl CFK Parts i«l. 332
and 243
Administrative practice and
procedure, Chemicals, Reporting and
Recordkeeping requirements. Water
supply.
Dated: December 31, 5920.
F. Heary Habic&i.
Acting Adziinistiator.
For the reasons set forth in the
preamble, chapter I of Title 40 of the
Code of Federal Regulations is proposed
to be amended as follows:
PAKY W—WAYDOMAL PHIR3AKV
1. The authority citation for part 141
continues to read as follows:
Authority: 42 U.S.C. 300f. 3COg-l. 300ff-2.
3COg-3. 3COg-4. 3C03-5. 3C03-3, 20t>H> and
300J-8.
2. Section 141.2 is amended by adding.
in alphabetical order, definitiono for
"Compliance cycle," "Compliance
period," "Initial compliance period." and
"repeat compliance period" to read as
follows:
§ 141.2 Dsrttnttteno.
6 « O ft ft
Compliance cycle means the nine-
year calendar year cycle during which
public water systems must monitor.
Each compliance cycle consists of three
three-year compliance periods. The first
calendar year cycle begins January 1,
1893 and er.ds December 31, 2001: the
second begins January 1, 2002 and ends
December 31, 2010: the third begins
January 1, 2011 and ends December 31.
2019.
Compliance period means a three-
year calendar year period within a
compliance cycle. Each compliance
cycle hcs three three-year compliance
periods. Within the first compliance
cycle, the first compliance period runs
from January 1. 1993 to December 31.
1995; the second from January 1. 1933 to
December 31, 1998; the third from
January 1. 1239 to December 31, 2001.
o 6 o e o
Initial compliance period means the
first full three-year compliance period
which begins at least 18 months after
promulgation.
o o a a o
Repeat compliance period means any
subsequent compliance period after the
initial compliance period.
o o o o o
3. In § 141.11, paragraph fb) is
amended by removing the entry for
"silver" from the table, and by revising
the introductory text cf paragraph (b) to
read as follows:
§ 1 4 1 . 1 1 Egsctoura eontonfilfsatrt towato ?e?
Inorganic etantesia.
(b) The following maximum
contaminant levels for cadmium.
chromium, mercury, nitrate, and
selenium shall remain effective until July
30. 1092.
6 tt
3. Section 161.12 is revised to read ao
follows:
§ 141.12 WtenlRium eorrtastfciont lowote tor
The following are the maximum
contaminant levels for organic
chemicals. The maximum contaminant
levels for organic chemicals in
paragraph (a) of this section apply to all
community water systems. Compliance
with the maximum contaminant level in
paragraph (a) of this section is
calculated pursuant to § 141.24. The
maximum contaminant level for total
trihalomethanes in paragraph (c) of thio
section applies only to community water
systems which serve a population of
-------
Federal Register / Vol. 56. No. 20 / Wednesday. January 30, 1991 / Rules and Regulations
3579
10.000 or more individuals and which
add a disinfectant (oxidant) to the water
in any part of the drinking water
treatment process. Compliance with the
maximum contaminant level for total
trihalomethanes is calculated pursuant
to S 141.30.
(a) Chlorinated hydrocarbons: Ervdnn
(1.2.3.4.10.10- hexachloro-6,7-
epoxy-1,4. 4a,5.6.7.B.81-octahydro-
1.4-onbo, ando-5,8-dimemano
naphthalene) -
(b) CReswved]
(c) Total trihalomethanes (the sum of
the concentrations of bromodichlo-
rometnane. dioromochloromemane,
tnbromometnane (bromotorm) and
trichkxomethane (chloroform))
Level.
milligrams
per liter
0.0002
0.1
4. Section 141.23 is revised to read as
follows:
§ 141.23 Inorganic chemical sampling and
analytical requirement*.
Community water systems shall
conduct monitoring to determine
compliance with the maximum
contaminant levels specified in § 141.82
in accordance with this section. Non-
transient, non-community water systems
shall conduct monitoring to determine
compliance with the maximum
contaminant levels specified in S 141.02
in accordance with this section.
Transient, non-community water
systems shall conduct monitoring to
determine compliance with the nitrate
and nitrite maximum contaminant levels
in { 141.11 and S 141.62 (as appropriate)
in accordance with this section.
(a) Monitoring shall be conducted as
follows:
(1) Groundwater systems shall take a
minimum of one sample at every entry
point to the distribution system which is
representative of each well after
treatment (hereafter called a sampling
point) beginning in the compliance
period starting January 1,1993. The
system shall take each sample at the
same sampling point unless conditions
make another sampling point more
representative of each source or
treatment plant.
(2) Surface water systems shall take a
minimum of one sample at every entry
point to the distribution system after
any application of treatment or in the
distribution system at a point which is
representative of each source after
treatment (hereafter called a sampling
point) beginning in the compliance
period beginning January 1,1993. The
system shall take each sample at the
same sampling point unless conditions
make another sampling point more
representative of each source or
treatment plant.
Note: For purposes of this paragraph.
surface water systems include systems with a
combination of surface and ground sources.
(3) If a system draws water from more
than one source and the sources are
combined before distribution, the
system must sample at an entry point to
the distribution system during periods of
normal operating conditions (i.e., when
water is representative of all sources
being used).
(4) The State may reduce the total
number of samples which must be
analyzed by allowing the use of
compositing. Composite samples from a
maximum of five sampling points are
allowed. Compositing of samples must
be done in the laboratory.
(i) If the concentration in the
composite sample is grea'er than or
equal to the detection limit of any
inorganic chemical, then a follow-up
sample must be taken within 14 days at
each sampling point included in the
composite. These samples must be
analyzed for the contaminants which
were detected in the composite sample.
Detection limits for each analytical
method are the following:
DETECTION LIMITS FOR INORGANIC CONTAMINANTS
Contaminant
Asbestos
Banum „
Cadmium
Chromium
Mercury .. .
Nitrate... .
Nitrite
MCL (mg/l)
7 MLF "
2
0005
0 1
0002
10 (as N)
1 (as N)
005
Transmission Electron Microscopy « - -
Atomic Absorption' furnace technique .-
Inductively Coupled Plasma .-.-
Atomic Absorption* furnace technique
Inductrvety Coupled Plasma .... . ,----, . ,
Manual Cold Vapor Technique
Manual Cadmium Reduction ~
Automated HytSrazine Reduction - -
Automated Cfidmium Reduction ..
Ion Selective Electrode
Ion Gfvoflietocnphy
Spectrophotometric - - .— -
AutomHted Cadmium Reduction , ,, .,,.,...,
Manual Cadmium Reduction
Ion Chromatography .,,, ,
Atomic Absorption* furnace
Atomic Absorption* gaseous hydride
Detection limit
(mg/l)
0.01 MFL
0.002
01
0.002(0.001) i
0.0001
0.001 '
0.001
0.007 (0001) '
0.0002
0.0002
0.01
0.01
0.05
1
0.01
0.01
0.05
0.01
0.004
0.002
0.002
1 Using concentration technique in Appendix A to EPA Method 200.7.
* MFL = million libers per htar >10 .m.
(ii) If the population served by the
system is > 3.300 persons, then
compositing may only be permitted by
the State at sampling points within a
single system. In systems serving O.300
persons, the State may permit
comr. ositing among different systems
provided the 5-sample limit is
maintained.
(5) The frequency of monitoring for
asbestos shall be in accordance with
paragraph (b) of this section; the
frequency of monitoring for barium,
cadmium, chromium, fluoride, mercury,
and selenium shall be in accordance
with paragraph (c) of this section; the
frequency of monitoring for nitrate shall
be in accordance with paragraph (d) of
this section; and the frequency of
monitoring for nitrite shall be in
accordance with paragraph (e) of this
section.
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35BO Federal Kegigter / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
(b) The frequency of monitoring
conducted to determine compliance with
the maximum contaminant level for
eabsstos specified in 5141.62(b) shall be
conducted aa fallows:
(1) Each community and non-
transient non-community water system
,is required to monitor for asbestos
during the first three-year compliance
period of each nine-year compliance
cycle beginning in the compliance period
starting January 1.1933.
(2) If the system believes it is not
•vulnerable to either asbestos
contamination in its source water or due
to corrosion of asbestos-cement pipe, or
both, it may apply to the State for a
waiver of the monitoring requirement in
paragraph (b)(l) of this section. If the
State grants the waiver, the system is
not required to monitor.
(3} The State may grant a waiver
based on a consideration of the
following factors:
(i) Potential asbestos contamination of
the water source, and
(ii) The use of asbestos-cement pipe
for finished water distribution and the
corrosive nature of the water.
(4) A waiver remains in effect until
the completion of the three-year
compliance period. Systems not
receiving a waiver must monitor in
accordance with the provisions of
paragraph (b)(l) of this section.
(5} A system vulnerable to asbestos
contamination due solely to corrosion of
asbestos-cement pipe shall take one
sample at a tap served by asbestos-
cement pipe and under conditions where
asbestos contamination is most likely to
occur.
(8) A system vulnerable to asbestos
contamination due solely to source
water shall monitor in accordance with
the provision of paragraph (a) of this
section.
(7) A system vulnerable to asbestos
contamination due both to its source
water supply and corrosion of asbestos-
cement pipe shall take one sample at a
tap served by asbestos-cement pipe and
under conditions where asbestos
contamination is most likely to occur.
(8) A system which exceeds the
maximum contaminant levels aa
determined in 9 141.23(1) of this section
shall monitor quarterly beginning in the
next quarter after the violation occurred.
(9) The State may decrease the
quarterly monitoring requirement to the
frequency specified in paragraph (b)(l)
of this section provided the State has
determined that the system is reliably
and consistently below the maximum
contaminant level In no case can a
State make this determination nnlen a
groundwater system takes a minimum of
two quarterly samples and a surface (or
combined surface/ground) water system
takes a minimum of four quarterly
samples.
(10) If monitoring data collected sfter
January l, 1990 are generally consistent
with the requirements of { 141.23(b),
then the State may allow systems to use
that data to satisfy the monitoring
requirement for the initial compliance
period beginning January 1,1993.
(c) The frequency of monitoring
conducted to determine compliance with
the maximum contaminant levels in
S 141.62 for barium, cadmium,
chromium, fluoride, mercury, and
selenium shall be as follows:
(1) Groundwater systems shall take
one sample at each sampling point
during each compliance period
beginning in the compliance period
starting January 1.1993. Surface water
systems (or combined surface/ground)
shall take one sample annually at each
sampling point beginning January 1,
1993.
(2) The system may apply to the State
for a waiver from the monitoring
frequencies specified in paragraph (c)(l)
' of this section.
(3) A condition of the waiver shall
require that a system shall take a
minimum of one sample while the
waiver is effective. The term during
which the waiver is effective shall not
exceed one compliance cycle (i.e., nine
years).
(4) The State may grant a waiver
provided surface water systems have
monitored annually for at least three
years and groundwater systems have
conducted a minimum of three rounds of
monitoring. (At least one sample shall
have been taken since January 1,1990).
Both surface and groundwater systems
shall demonstrate that all previous
analytical results were less than the
m«itim\im contaminant level. Systems
that use a new water source are not
eligible for a waiver until three rounds
of monitoring from the new source have
been completed.
(S) In determining the appropriate
reduced monitoring frequency, the State
shall consider
(i) Reported concentrations from all
previous monitoring;
(ii) The degree of variation in reported
concentrations; and
(Ui) Other factors which may affect
contaminant concentrations such as
changes in groundwater pumping rates,
changes in the system's configuration,
changes in the system's operating
procedures, or changes in stream flows
or characteristics.
(6) A decision by the State to grant a
waiver shall be made in writing and
shall set forth the basis for the
determination. The determination may
be initiated by the State or upon an
application by the public water system.
The public water system shall specify
the basis for its request. The State shall
review and, where appropriate, revise
its determination of the appropriate
monitoring frequency when the system
submits new monitoring data or wher
other data relevant to the system's
appropriate monitoring frequency
become available.
(7) Systems which exceed the
maximum contaminant levels as
calculated in $ 141.23(1) of this section
shall monitor quarterly beginning in the
next quarter after the violation occurred.
(6) The State may decrease the
quarterly monitoring requirement to th >
frequencies specified in paragraphs
(c)(l) and (c)(2) of this section provided
it has determined that the system is
reliably and consistently below the
maximum contaminant level. In no case
can a State make this determination
unless a gronndwater system takes a
mipjpnim of two quarterly samples and
a surface water system takes a minimum
of four quarterly samples.
(d) All public water systems
(community; non-transient, non-
community; and transient, non-
community systems) shall monitor to
determine compliance with the
maximum contaminant level for nitrate
hi {141.62.
(1) Community and non-transient
non-community water systems served
by groundwater systems shall monitor
annually beginning January 1,1993;
systems served by surface water shall
monitor quarterly beginning January 1,
1993.
(2) For community and non-transient
non-community water systems, the
repeat monitoring frequency for
groundwater systems shall be quarterly
for at least one year following any one
sample in which the concentration is
>50 percent of the MCL The State may
allow a groundwater system to reduce
the sampling frequency to annually after
four consecutive quarterly samples are
reliably and consistently less than the
MCL
(3) For community and non-transient
non-community water systems, the State
may allow a surface water system to
reduce the sampling frequency to
annually if all analytical results from
four consecutive quarters are < SO
percent of the MCL A surface water
system shall return to quarterly
monitoring if any one sample is >SO
percent of the MCL
(4) Each transient non-community
water system shall monitor annna ly
beginning January 1,1993.
-------
Federal Register / Vol. 56. No. 20 / Wednesday. January 30, 1991 / Rules and Regulations 3SB1
(5) After the initial round of quarterly
sampling is completed, each community
and non-transient non-community
system which is monitoring annually
shall take subsequent samples during
the quarter(s) which previously resulted
in the highest analytical result.
(e) All public water systems
(community; non-transient, non-
community; and transient, non-
community systems) shall monitor to
determine compliance with the
maximum contaminant level for nitrite
in i 141.62(b).
(1) All public water systems shall take
one sample at each sampling point in the
compliance period beginning January 1.
1993 and ending December 31,1995.
(2) After the initial sample, systems
where an analytical result for nitrite is
<50 percent of the MCL shall monitor at
the frequency specified by the State.
(3) For community, non-transient, non-
community, and transient non-
community water systems, the repeat
monitoring frequency for any water
system shall be quarterly for at least one
year following any one sample in which
the concentration is >50 percent of the
MCL. The State may allow a system to
reduce the sampling frequency to
annually after determining the system is
reliably and consistently less than the
MCL.
(4) Systems which are monitoring
annually shall take each subsequent
sample during the quarter(s) which
previously resulted in the highest
analytical result.
(f) Confirmation samples:
(1) Where the results of sampling for
asbestos, barium, rarimtmn, rJirnmiiipn,
fluoride, mercury, or aetenhnn indicate
an exceedance of the maximum
contaminant level, the State may require
that one additional sample be collected
as soon as possible after the initial
sample was taken (but not to exceed
two weeks) at the same sampling point.
(2) Where nitrate or nitrite sampling
results indicate an ^xce&udiiCe of the
maximum contaminant level, the system
shall take a confirmation sample within
24 hours of the system's receipt of
notification of the analytical results of
the first sample. Systems unable to
comply with the 24-hour sampling
requirement must immediately notify the
consumers served by the area served by
the public water system in accordance
with 5 141.32. Systems exercising th™
option must take and analyze a
confirmation sample within two weeks
of notification of the analytical results of
lha first sample.
(3) If a State-required confirmation
sample is taken for any contaminant,
then the results of the initial and
confirmation sample shall be averaged.
The resulting average shall be used to
determine the system's compliance in
accordance with paragraph (i) of this
section. States have the discretion to
delete results of obvious sampling
errors.
(g) The State may require more
frequent monitoring then specified in
paragraphs (h), (c). (d) and (e) of this
section or may require confirmation
samples for positive and negative results
at its discretion.
(h) Systems may apply to the State to
fxinHiirt more frequent monitoring than
the minimum monitoring frequencies
specified in this section.
(i) Compliance with (S 141.11 or
141.62(b) fas appropriate) shall be
determined based on the analytical
result(s) obtained at each sampling
point
(1) For systems which are conducting
monitoring at a frequency greater than
annual, compliance with the maximum
contaminant levels for asbestos, barium.
cadmium, chromium, fluoride, mercury,
and selenium is determined by a running
annual average at each sampling point.
If the average at any sampling point is
greater than the MCL, then the system is
out of compliance. If any one sample
would cause the annual average to be
exceeded, then the system is out of
compliance immediately. Any sample
below the detection limit shall be
calculated at zero for the purpose of
determining the annual average.
(2) For systems which are monitoring
annually, or less frequently, the system
is out of compliance with the maximum
contaminant levels for asbestos, barium,
cadmium, chromium, fluoride, mercury
and selenium if the level of a
contaminant at any sampling point is
greater than the MCL If a confirmation
sample is required by the State, the
determination of compliance will be
based on the average of the two
samples.
(3) Compliance with the maximum
contaminant levels for nitrate and
nitrate is determined based on one
sample if the levels of these
contaminants are below the MCLs. If the
levels of nitrate and/or nitrite exceed
the MCLs in the initial sample, a
confirmation sample is required in
accordance with paragraph (f)(2) of this
section, and compliance shall be
determined based on the average of the
initial and confirmation samples.
(4) If a public water system has a
distribution system separable from other
parts of the distribution system with no
interconnections, the State may allow
the system to give pubhc notice to only
the area served by that portion of the
system which is out of compliance.
(J) Each public water system shall
monitor at the time designated by the
State during each compliance period.
(k) Inorganic analysis:
(1) Analysis for asbestos, barium.
cadmium, chromium, mercury, nitrate.
nitrite, and selenium shall be conducted
using the following methods:
INORGANIC CONTAMINANTS ANALYTICAL METHODS
Contaminant
Asbestos
Chromium
Nitrfttf*
Nitrite
Methodology •'
Transmission Electron Microscopy «
AtfKtrc ttoaorplrofr direct Mptrttion
Irrrtircyrvety coupled pieerne, ,,..,.„,„— , ,,. -..
Atomic tbsotpoorv furnace technique .«. «.-
irtaucUvely-coupted ptume
Automated riytfriji*** reduction _
Automated Cftdmiu™ r*fluciion .. ...
ton ffVArtiuA altt^rn0A ,.,. , ... ,, „..,_. . , .. . ...
Ion ctvomatCQTApriy ,- r - , -. . -- .. -. .-. -
Spectropnotornotrtc
EPA '
EPA*
2082
206.1
200 7 ^
911 9
200.7A*
216.2
200.7 '••
245 1
245.2
9533
953.1
353.2
900.0
354.1
ASTM>
03223-80
D3867-85B
D3867-85A
SU>
304
303C
304
304'
303C
418C
418F
Other
wawwG/seeo *
B-1001 >°
-------
35®2 Fsdeml IREgLsfos? / Vol. 58. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
i
INORGANIC CONTAMINANTS ANALYTICAL METHODS—Continued
Contaminant
Selenium
~
Methodology "
Automated codmium reduction ,, . .... _„,.„,...., ,,.. ,-..
Manual cadmium reduction ™ .- .. ™ « «
Ion chromatography . .. .— — ..
Atomic nbocrptiofi; tumsco technique ..
EPA-
353.2
353.3
300.0
270.3
270.2
Reloronco (method No.
ASTM"
D3B67-S5A
D3867-85B
D3658-84A
D385S-84B
SM°
418F
41BC
303E
304°
Other
B-1011 >«
l-38S7-eS«
' "Methods ol Chornical Analysis) ol Water and Wastes." EPA Environmental Monitonng ond Support Laboratory, Cincinnati. OH 45268 (EPA-600/4-7&-020).
March 1803. Available from ORD Publications. CEHI. EPA. Cincinnati. OH 45268.
'Arand Booh ol ASTM Standards, Vol. 11.01 American Sociaty lor Tosting and Matan'als. 1961 Raco Straat Philadelphia. PA 19103.
° "Standard Motnodo tor tho Examination ol Water and Wasiawaior." 16th edition. American Public Health Association, Amsncan Water Worto Aoccciation. Wotw
Pollution Control Fcdoraton, 1885.
" "Mothodo tor Determination tH Inorganic Substances in Water and Fluvbl Ssdirronts," Techniques ol Watcr-Resourceo Investigations of tho U.S. GcoJogxal
Survey Bcoto, Chapter A1. 1985, Opon-Frb Report 05-195. Available Irom OporvKito Services Section. Western Distribution Branch, U.S. Geoto&col Survey, MS 308
Bos 2432S, Denver Federal Corttor. Denver, CO 80225.
0 "Orion Guido Co Wotcr and Waoteratcr Anatysio." Form WoWWG/5880, p. 5. 1985. Orion Rssoarch. Inc.. Cambridge. MA.
0 200.7A "Inductivcly-Ccujjfcd Ptooma Atomic Emission Analysis ol Drinlung Water." Appertain to Method 2C0.7, March. 1987. U.S. EPA, Environments! Monficrtng
ond Support Laboratory, Cincinnati, OH 45266.
'The addition ol 1 mL ol 30SS H,Oto to each 100 mL ol otandarrto and (samples A. Cincinnati. Ohio «32aa fat
analytical pratodureo for iaotab. tko
oppllcnblo to total Biotob lauot bo used
D "Standard Methodo fb7 IAQ Esa&ilnattoa of
Wator and Waotoootar." lath Sditiosa. Amohcon
ITuhlic Health Acoodation. Aj&sricoa Walay Woriui
Accodattoa. Wator Follotioa Contra] Fodarotioa.
1E38.
0 TQchalquoo of Wato7-Rcoosraoo InvcatiQation of
tho United Statca CooScalcoS Surooy. Gjaptor A-l.
"IbGotfeBjJfl for Ootcnninabo^ of InofiiQEESc
Subolancaa la Wotor and Fluvial Ssdlmanta." Booh
8.107B. Stoch OmO-nm-03177-9. Avallablo bam
Supaiintonaaat o? Docassaato. VS. Covoraaaat
Printing OSico, WoDhinglosj. DC SKS&.
o Annual Eooh of ASTM Stnndnifdo. part SI Wato?
American Sodoty lm Tooting and Matocialo. 1C1Q
Rcco Street. Piillndolpbla, Ponnoylvanla 16103.
-------
Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3583
^ — ^ — -_ — ^ — ^ ^^^__ ._, ___, _n
Contaminant
Mercury
Nitrite:
Chlorinated _
Non-chlonnatec!
Nitrite
Selenium ...
Preservative '
Cone HNO> to pH <2
Cool 4 'C
Cone H.SCX to pH <2 „
Cool 4 'C -
Cone HNOi to pH <2
Container *
G
P
Por G
For G
Pot G
Pot G
Time*
28 davs.
14 oays.
2S davs.
14 oays.
46 hours
6 mentis.
11) HMO) cannot be used because of shipping restrictions, sample may be initially preserved by icing and immediately snipping it la tne Isboratorv. Upon rece:;t
in the laboratory, trie sample rr.usl be acidified witn cone HNO, to pH <2. At time of analysis, sample container snould be thorougnly nnsed w.trt 1:1 HNO.: wajnmcs
should be added to samp p.
: P — plastic, hard or soil; G - glass, hard or soft.
' In ell cases, samples sho-ld be analyzed as soon after collection as possible.
(5) Analysis under this section shall
only be conducted by laboratories that
have received approval by EPA or the
State. To receive approval to conduct
analyses fcr asbestos, barium, cadmium,
chromium, fluoride, msrcury. nitrate.
nitri'.e and selenium the laboratory must:
(i) Analyze Performance Evaluation
samples which include those substances
provided by EPA Environmental
Monitoring and Support Laboratory or
equivalent samples provided by the
State.
(ii) Achieve quantitative results on the
analyses that are within the following
acceptance limits:
Contaminant
Abestos
Barium --,,,
Cadmium
Fluoride
Mercury
Nitrmta
Nitrate
SaJenium
Acceptance limit
2 standard deviation* based on study
statistics.
±15% at j 0.15 mg/l.
±20% tt £ 0.002 rng/1.
±15% at 2 0.01 mg/l.
±10% at 1 to 10 mg/l.
±30% at 2 0.0005 mg/l.
±10% at 20.4mg/L
±15% at ^ 0.4 mg/l.
±20% at 2 0.01 mg/l.
S. In S 141.24. paragraph (a) the
introductory text paragraph (e), and
paragraph (f) are revised, and a new
paragraph (h) is added to read as
follows:
S 141.24 Organic chemicals other than
total trlhalomathants, sampling and
analytical requirements.
(a) Monitoring of endrin for purposes
of determining compliance with the
maximum contaminant level listed in
S 141.12(a) shall be conducted as
follows:
«•*•)*
(e) Analysis made tp determine
compliance with the maximum
contaminant level for endrin in
§ 141.12(a) shall be made in accordance
with Method 508. "Determination of
Chlorinated Pesticides in Water by Gas
Chromatography with and Electron
Capture Detector." in "Methods for the
Determination of Organic Compounds in
Drink'ng Water," ORD Publications.
CERI. EPA/600.'4-68/039. December
198S.
* • • • *
(f) Analysis of the contaminants listed
in § 141.61(a) (9) through (18j for the
purpose of determining compliance with
the maximum contaminant level shall be
conducted as follows:
(1J Groundwater systems shall take a
minimum of one sample at every entry
point to the distribution system which is
representative of each well after
treatment (hereafter called a sampling
point). If conditions warrant, the State
may designate additional sampling
points within the distribution system or
at the consumer's tap which more
accurately determines consumer
exposure. Each sample must be taken at
the same sampling point unless
conditions make another sampling point
more representative of each source or
treatment plant.
(2) Surface water systems shall take a
minimum of one sample at points in the
distribution system that are
representative of each source or at each
entry point to the distribution system
after treatment (hereafter called a
sampling point). If conditions warrant.
the State may designate additional
sampling points within the distribution
system or at the consumer's tap which
more accurately determines consumer
exposure. Each sample must be taken at
the same sampling point unless
conditions make another sampling point
more representative of each source,
treatment plant, or within the
distribution system.
Note: For purposes of this paragraph,
surface water systems include systems with a
combination of surface end ground surfaces.
(3) If the system draws water from
more than one source and the sources
are combined before distribution, the
system must sample at an entry point to
the distribution system during periods of
normal operating conditions (i.e.. when
water representative of all sources is
being used).
(4) Each community and non-transient
non-community water system shall take
four consecutive quarterly samples for
each contaminant listed in 5 Kl.Gl(o)
(a) through (13) during each compliance
period beginning in the compliance
period starting January 1,1993.
(5) Groundwaier systems which do
not detect one cf the contaminants listed
in § 141.61(a) (9) through (18) after
conducting the initial round cf
monitoring required in paragraph [f}[4]
cf this section shall take one samp'i3
annually.
(6) If the initial monitoring for
contaminants listed in § 141.81 (a) (9)
through (10) as allowed in paragraph
(f)(18) of this section has been
completed by December 31.1992 and the
system did not detect any contaminant
listed in $ 141.61(a) (1) through (18) then
the system shall take one sample
annually beginning January 1,1993.
After a minimum of three years of
annual sampling, the State may allow
groundwater systems which have no
previous detection of any contaminant
listed in $ 141.61(a) to take one sample
during each compliance period.
(7) Each community and non-transient
water system which does not detect a
contaminant listed in J 141.61(a) (1)
through (18) may apply to the State for a
waiver from the requirement of
paragraph (f)(4) and (f)(5) of this section
after completing the initial monitoring.
(For the purposes of this section.
detection is defined as >0.0005 mg/l.) A
waiver shall be effective for no more
than six years (two compliance periods).
(8) A State may grant a waiver after
evaluating the following factors):
(i) knowledge of previous use
(including transport, storage, or
disposal) of the contaminant within the
watershed or zone of influence of the
system. If a determination by the State
reveals no previous use of the
contaminant within the watershed or
zone of influence, a waiver may be
granted.
(ii) If previous use of the contaminant
is unknown or it has been used
previously, then the following factors
shall be used to determine whether a
waiver is granted.
(A) Previous analytical results.
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35S-S Federal
/ Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations
i'3) The proximity of the system to
potential point or non-point source of
contamination. Point sources include
r pills and leaks of chemicals at or near a
water trc.it.Ti2m facility or at
manufacturing, distribution, or storage
faciiitioa. or from hazardous and
niur.icipe! waste landfills and other
•vcste handling or treatment facilities.
(C) The cnv.ronmentol persistence
and transport of the contaminants.
fr;) Ths number of persons served by
the public water system and the
proximity of a smaller system to a larger
system.
[C) How vreii the water source is
r -elected against contamination such es
whether it is a surface or groandwater
system. Grouuawater systems must
consider factors such as depih of the
w::!, the type of soil, and wellhead
protection. Surface water systems must
cr.-sidrr watershed protection.
i?) As a condition of the waiver a
;ys:an; must take one sample at each
r-ampKng pcint during the time the
v/aiver :s effective (i.e.. one cample
during tivo compliance periods or six
years), and update its vulnerability
assessment considering the factors
listed in paragraph (f)(8) cf this section.
Based on this vulnerability assessment
the Siate must confirm that the system is
non-vulnerable. If the State does not
make this reconfirmation within three
years of the initial determination, then
the waiver is invalidated and ths system
is required to sample annually as
specified in paragraph (f){5) of this
section.
(10] A surface water system which
does not detect a contaminant listed in
5 14l.61(a) (1) through (IB) and is
(istermined by the State to be non-
vulnerable using the criteria in
paragraph (0(8) of this section shall
monitor at the frequency specified by
the State (if snyj. Systems meeting this
criteria must be determined by the Stats
to be non-vulnerable based on a
vulnerability assessment during each
compliance period.
(11) If a contaminant listed in
§ 141.61(a) (3) through (18) is detected ^t
a level exceeding O.OC05 mg/1 in any
sample, then:
(i) The system must monitor quarterly
at each sarr.riir.g point which resulted in
a detection.
(ii) The biate may decrease the
quarterly monitoring requirement
specified in paragraph (f)(ll)(i) of this
section provided it has determined that
t the system is reliably and consistently
bslcw the maximum contaminant level.
In no case shall the State msks this
determination unless a groundwater
system takes a minimum of two
quarterly samples and a surface water
system takes a minimum cf four
quarterly samples.
(iiij If the State tit terminus that the
system is reliably and consistently
belo-.v ths MCL. the Slate may aliow the
system to monitor annually. Systems
which rr.cr.iior annually must monitor
during ihe querter(s) which previously
yielded the hiahc?£t analytical result.
(iv) Systems which have three
consecutive annual samples with no
detection cf a contaminant may apply to
the Siats for a waiver es specified in
paragraph (i){7) of this stciion.
(v) (Reserved)
(12) Systems which violate the
requirements of § 141.01JD) (9) through
(IS) as deterrr.ined by paragraph (0(16)
of this section must monitor quarterly.
After a minimum of four quarterly
samples shows the system is in
compliance es specified in paragraph
(f)(lC) cf this section, and the State
determines that the system is reliably
trid consistently below the maximum
contaminant level, the eystem may
monitcr et ihe frequency and time
specified in paragraph (f)(ll)(iii) of this
section.
(13) The State may require a
confirmation sample for positive or
negative results. If a confirmation
sample is required by the State, the
result must be averaged with the first
sampling result and the average is used
far the compliance determination as
specified by paragraph (0(16) of this
section. States have discretion to delete
results of obvious sampling errors from
this calculation.
(14) The State may reduce the total
number of samples a system must
analyze by allowing the use of
corrposiunc. Composite samples from a
maximum cf five sampling points are
allowed. Compositing of samples must
be done in -he laboratory and analyzed
within 14 days of sample collection.
(i) If ths concentration in the
composite sample is ^ O.CCOS mg/1 for
any contaminant listed in % 141.Cl(a),
then a follow-up sample must be taken
in analyzed within 14 days from each
sampling point included in the
composite.
(ii) If duplicates of the original sarr.ple
taken from each sampling point used in
the composite are available, the system
may use these instead of resampling.
The duplicate must be analyzed and the
results reported to the State within 14
uays of collection.
(iii) If the population served by the
system is > 3.300 persons, then
compositing may only be permitted by
by the State at sampling points within a
single system. In systems serving <3,300
persons, the State may permit
compositing among different syotemo
provided the 5-semple limit is
maintained.
(iv) Compositing samples prior to GC
analysis.
(A) Add 5 ml or equal larger emounts
of each sample (up to 5 samples are
allowed) to a 25 ml glass syringe.
Special precautions must be made to
maintain zero headipoce in the syringe.
(B) The samples must be cooled at 4"
C during this step to minimize
volatilization losses.
(C) Mix v/eil and dra\v out a 5-ml
aliquot for analysis.
(D) Follow sample introduction,
purging, and desorption steps described
in the method.
(£) If less than five samples are used
for compositing, a proportionately small
syrirre may be used.
(v) Compos.ling samples prior to GC/
MS analysis.
(A) Inject S-ml or equal larger
amounts of each aqueous sample (up to
5 samples are allowed) into a 25-ml
purging device using the sample
introduction technique described in the
method.
(3) The total volume of the sample in
the purging device must bs 25 ml.
(C) Purge and desorb as described in
the msthoti.
(15) Compliance with § 141.61(a) (9)
through (18) shall be determined based
on the analytical results obtained at
each sampling point.
(i) For systems which are conducting
monitoring at a frequency greater than
annual, compliance is determined by a
running annual average of all samples
taken at each sampling point. If the
annual average of any sampling point is
greater than the MCL. then the system is
out of compliance, if the initial sample
or a subsequent sample would cause the
annual average to be exceeded, then the
system is out of compliance
immediately. Ary samples beicw the
detection limit shall be calculated as
zero for purposes of determining the
annual average.
(ii) If monitoring is conducted
annually, or less frequently, ths system
is out of compliance if the level of a
contaminant at cny sampling point is
greater than the MCL. If a confirmation
sample is required by ths State, the
determination of compliance will be
based on the average of two samples.
(i.i) If a public water system has a
distribution system separable from other
parts of the distribution system with no
interconnections, the State may allow
the system to give public notice to only
that area served by that portion of thn
system which is out of compliance.
(16) Analysis for the contaminants
listed in § 141.61 (a) (9) through (18) shall
-------
Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3585
be conducted using the following EPA
methods or their equivalent as approved
by EPA. These methods are contained in
"Methods for the Determination of
Organic Compounds in Drinking Water",
ORD Publications, CERI, EPA/600/4-88/
039, December 1988. These documents
are available from the National
Technical Information Service (NTIS),
U.S. Department of Commerce. 5285 Port
Royal Road, Springfield. Virginia 22161.
The toll-free number is 800-336-4700.
(i) Method 502.1. "Volatile
Halogenated Organic Chemicals in
Water by Purge and Trap Gas
Chroma tography."
(ii) Method 502.2. "Volatile Organic
Compounds in Water by Purge and Trap
Capillary Column Gas Chromalography
with Photcionization and Electrolytic
Conductivity Detectors in Series."
(iii) Method 503.1. "Volatile Aromatic
and Unsaturated Organic Compounds in
Water by Purge and Trap Gas
Chromatography."
(iv) Method 524.1. "Measurement of
Purgeable Organic Compounds in Water
by Purged Column Gas
Chromatography/Mass Spectrometry."
(v) Method 524.2. "Measurement of
Purgeable Organic Compounds in Water
by Capillary Column Gas
Chromatography/Mass Spectrometry."
(17) Analysis under this section shall
only be conducted by laboratories that
have received approval by EPA or the
State according to the following
conditions:
(i) To receive conditional approval to
conduct analyses for the contaminants
in 9141.61(a) (9) through (18) the
laboratory must
(A) Analyze Performance Evaluation
samples which include these substances
provided by EPA Environmental
Monitoring and Support Laboratory or
equivalent samples provided by the
State.
(B) Achieve the quantitative
acceptance limits under paragraphs
(f)(18)(i) (C) and (D) of this section for at
least 80 percent of the regulated organic
chemicals listed in § 141.61(a) (2)
through (18).
(C) Achieve quantitative results on
the analyses performed under paragraph
(0(lB)(i)(A) of this section that are
within ±20 percent of the actual amount
of the substances in the Performance
Evaluation sample when the actual
amount is greater than or equal to 0.010
mg/1.
(D) Achieve quantitative results on
the analyses performed under paragraph
(f)(18)(i)(A) of this section that are
within ±40 percent of the actual amount
of the substances in the Performance
Evaluation sample when the actual
amount is less than 0.010 mg/1.
(E) Achieve a method detection limit
of 0.0005 mg/1. according to the
procedures in Appendix B of part 136 of
this chapter.
(F) Be currently approved by EPA or
the State for the analyses of
trihalomethanes under {141.30.
(ii) [Reserved]
(18) States may allow the use of
monitoring data collected after January
1.1988 required under section 1445 of
the Act for purposes of monitoring
compliance. If the data are generally
consistent with the other requirements
in this section, the State may use those
data (i.e.. a single sample rather than
four quarterly samples) to satisfy the
initial monitoring requirement cf
paragraph (f)(4) of this section.
(19) States may increase required
monitoring where necessary to detect
variations within the system.
(20) Each approved laboratory must
determine the method detection limit
(MDL). as defined in Appendix B to Part
136 of this chapter, at which it is capable
of detecting VOCs. The acceptable MDL
is 0.0005 mg/1. This concentration is the
detection concentration for purposes of
this section.
(21) Each public water system shall
monitor at the time designated by the
State within each compliance period.
• • • » •
(h) Analysis of the contaminants
listed in { 141.61(c) for the purposes of
determining compliance with the
maximum contaminant level shall be
conducted as follows:
(1) Groundwater systems shall take a
minimum of one sample at every entry
point to the distribution system which is
representative of each well after
treatment (hereafter called a sampling
point). Each sample must be taken at the
same sampling point unless conditions
make another sampling point more
representative of each source or
treatment plant.
(2) Surface water systems shall take a
minimum of one sample at points in the
distribution system that are
representative of each source or at each
entry point to the distribution system
after treatment (hereafter called a
sampling point). Each sample must be
taken at the same sampling point unless
conditions make another sampling point
more representative of each source or
treatment plant.
Note: For purpoies of thi* paragraph.
•urface water systems include system* with a
combination of surface and ground sources.
(3) If the system draws water from
more than one source and the sources
are combined before distribution, the
system must sample at an entry point to
the distribution system during periods of
normal operating conditions (i.e., when
water representative of all sources is
being used).
(4) Monitoring frequency:
(i) Each community and non-transient
non-community water system shall take
four consecutive quarterly samples for
each contaminant listed in 5 141.61(c)
during each compliance period
beginning with the compliance period
starting January 1.1993.
(ii) Systems serving more than 3.300
persons which do not detect a
contaminant in the initial compliance
period may reduce the sampling
frequency to a minimum of two
quarterly samples in one year during
each repeat compliance period.
(iii) Systems serving less than or equal
to 3.300 persons which do not detect u
contaminant in the initial compliance
period may reduce the sampling
frequency to a minimum of one sample
during each repeat compliance period.
(5) Each community and non-transient
water system may apply to the State for
a waiver from the requirement of
paragraph (h)(4) of this section. A
system must reapply for a waiver for
each compliance period.
(6) A State may grant a waiver after
evaluating the following factor(s):
Knowledge of previous use (including
transport storage, or disposal) of the
contaminant within the watershed or
zone of influence of the system. If a
determination by the State reveals no
previous use of the contaminant within
the watershed or zone of influence, a
waiver may be granted. If previous use
of the contaminant is unknown or it has
been used previously, then the following
factors shall be used to determine
whether a waiver is granted.
(i) Previous analytical results.
(ii) The proximity of the system to a
potential point or non-point source of
contamination. Point sources include
spills and leaks of chemicals at or near a
water treatment facility or at
manufacturing, distribution, or storage
facilities, or from hazardous and
municipal waste landfills and other
waste handling or treatment facilities.
Non-point sources include the use of
pesticides to control insect and weed
pests on agricultural areas, forest lands,
home and gardens, and other land
application uses.
(iii) The environmental persistence
and transport of the pesticide or PCBs.
(ii) How well the water source is
protected against contamination due to
such factors as depth of the well and the
type of soil and the integrity of the well
casing.
(v) Elevated nitrate levels at the water
supply source.
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35SS F®d®Fel Regaaltes1 / Vol. 53, No. 20 / Wednesday, January 30, 1S91 / Rules and Regulations
,'vi) Use cf PCBs in equipment used in
the production, storage, or distribution
cf v/ater (i.e., PCBs used in pumps,
transformers, etc.).
(7) If an organic contaminant listed in
§ 141.61(c) is detected (as defined by
paragraph (h)(18) of this section) in any
sample, then:
(!) Each system must monitor
quarterly at each sampling point which
resulted in a detection.
(ii) The State msy decrease the
quarterly monitoring requirement
specified in paragraph fn)(7)(i) of this
section provided it has determined that
the system is reliably and consistently
below the maximum contaminant level.
In no case shall the State make this
determination urJess a ground-water
system takes a minimum of two
quarterly samples and a surface water
system takes a minimum of four
quarterly samples.
(iii) After the State determines the
system is reliably and consistently
below the maximum contaminant level
the State may allow the system to
monitor annually. Systems which
monitor annually must monitor during
the quarter that previously yielded the
highest analytical result
(iv) Systems which have 3 consecutive
annual samples with no detection of a
contaminant may apply to the State for
a waiver as specified in paragraph (h)(6)
of this section.
(v) If monitoring results in detection of
one or more of certain related
contaminants (aldicarb, aldicarb
sulfone, aldicarb sulfoxide and
heptachlor, heptachlor epoxide). then
subsequent monitoring shall analyze for
ell related contaminants.
(8) Systems which violate the
requirements of g 141.81(c) as
determined by paragraph (h)(12) of this
section must monitor quarterly. After a
maximum of four quarterly samples
show the system is in compliance and
the State determines the system is
reliably end consistently below the
MCL as specified in paragraph (h)(ll) of
this section, the system shall monitor at
the frequency specified in paragraph
(h)(7)(iii) cf this section,
(9) The State may require a
confirmation sample for positive cr
negative results. If a confirmation
cample is required by the State, the
result must be averaged with the first
sampling result and the average used for
the compliance determination as
specified by paragraph (h)(il) of this
section. States have discretion to delete
results of obvious sampling errors from
this calculation.
(10) The State may reduce the total
number of samples a system must
analyze by allowing the use of
compositing. Composite samples from a
maximum cf five sampling points are
allowed. Compositing of samples must
be done in the laboratory and analyzed
within 14 days of sample collections.
(i) If the concentration in the
composite sample detects one or more
contaminants listed in § 141.61(c). then a
follow-up sample must be taken and
analyzed within 14 days from eacn
sampling point included in the
composite.
(ii) If duplicates of the original sample
taken from each sampling point used in
the composite are available, the system
nay use these duplicates instead of
resampling. The duplicate must be
analyzed and the results reported to the
State within 14 days of collection.
(iii) If the population served by the
system is > 3,300 persons, then
compositing may only be permitted by
the State at sampling points within a
single system. In systems serving O.3CO
persona, the State may permit
compositing among different systems
provided the 5-aampie limit is
maintained.
(11) Compliance with § 14i.61(c) shall
be determined based on the analytical
results obtained at each sampling point.
(i) For systems which are conducting
monitoring at a frequency greater than
annual, compliance is determined by a
running annual average of all samples
taken at each sampling point. If the
annual average of any sampling point is
greater than the MCL then the system ia
out of compliance. If the initial sample
or a subsequent sample would cause the
annual average to be exceeded, then the
system is out of compliance
immediately. Any samples below the
detection limit shall be calculated as
zero for purposes of determining the
annual average.
(ii) If monitoring is conducted
annually, or less frequently, the system
is out of compliance if the level of a
contaminant at any sampling point is
greater than the MCL If a confirmation
sample ie required by the State, the
determination of compliance will be
baaed on the average of two samples.
(iii) If a public water system has a
distribution system separable from other
parts of the distribution system with no
interconnections, the State may allow
the system to give public notice to only
that portion of the system which is out
of compliance.
(12) Analyoio for the contaminants
listed in § 141.81(c) shall be conducted
using the following EPA methods or
their equivalent as approved by EPA.
Theoe methods are contained in
"Methods for the Determination of
Organic Compounds in Drinking Water,"
ORD Publications. CERI, EPA/effi)/
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Federal Register / Vol. 56. No. 20 / Wednesday. January 30.1991 / Rules and Regulations 0S87
(13) Analysis for PCBs shall be
conducted as follows:
(i) Each system which monitors for
PCBs 4hail analyze each sample using
either Method 505 or Method 508 (see
paragraph (h)(13) of this section).
(ii) If PCBs (as one of seven Aroclors)
are detected (as designated in this
paragraph) in any sample analyzed
using Methods 505 or 506. the system
shall reanalyze the sample using Method
508A to quantitale PCBs (as
decachlorobiphenyl).
Ccmamnanl
Aroclor
1016
1221
1232
1242
1248
1254.
1260
DeMcton
ton* (mg/l)
0.00008
002
00005
00003
O.OC01
OOOC1
0000?
(iii) Compliance with the PCB MCL
shall be determined based upon the
Quantitative results of analyses using
Method SOEA.
(14) If monitoring data collected after
January 1.1990. are generally consistent
with the requirements of § 141.24(h).
then the State may aliow systems to use
that data to satisfy the monitoring
requirement for the initial compliance
period beginning January 1,1903.
(15) The State may increase the
required monitoring frequency, where
necessary, to detect variations within
the system (e.g., fluctuations in
concentration due to seasonal use,
changes in water source).
(16) The State has the authority to
determine compliance or initiate
enforcement action based upon
analytical results and other information
compiled by their sanctioned
representatives and agencies.
(17) Each public water system shall
monitor at the time designated by the
State within each compliance period.
(IB) Detection as used in this
paragraph shall be defined as greater
than or equal to the following
concentrations for each contaminant.
Dstsotton fcnvt
(mo/l)
O.OOC2
.0005
J0005
.0008
.0031
.oooa
D002
.00002
.0001
.OOC01
.00004
.00002
Atachlor.
AMc«t>_
Attcsto wKonde.
Aktesa> auHonc —
AtraziAfi ________
Cvtoofuran .
Detection Kntrt
tmg/l)
Lindw... _ -
Methoxycftlor ._..
Potychlonnated biphenyis (PCBs)
(ai decachtorotapnenyi;
Pontachlorophanol
Toxaphvne _.— .
2.4.5-TP (SilvexJ .._
.00002
.0001
.0001
.00004
.001
.0002
DttxomocNoropra
M (DBCP)
2.4-0
Ethytone dtaoir-Ue CEDE)
Heptachtor.._ ..... ________
HenxcMor tponde
B. In 9 141.32. paragraph (a)(l)(iii)(B) is
revised, paragraphs (e) (13). (14). (16).
(25). (26). (27). and (46) ere reserved, and
paragraphs (e) (15). (17) through (24),
(20) through (45|. and (47) through (52)
are added to read as follows:
§ 141.32 Public notification.
(a) ' * •
(I)'''
(iii) ' ' *
(B) Violation of the MCL for nitrate or
nitrite as defined in { 141.62 and
determined according to S 141.23(i)(3).
* • * * *
(e)* * '
(13HU) (Reserved)
(15) Asbestos. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that asbestos fibers greater
than 10 micrometers in length are a
health concern at certain levels of
exposure. Asbestos is a naturally
occurring mineral. Most asbestos libers
in drinking water are less than 10
micrometers in length and occur in
drinking water from natural sources and
from corroded asbestos-cement pipes in
the distribution system. The major uses
of asbestos were in the production of
cements, floor tiles, paper products,
paint, and caulking: in transportation-
related applications; and in the
production of textiles and plastics.
Asbestos was once a popular insulating
and fire retardent material. Inhalation
studies have shown that various forms
of asbestos have produced lung tumors
in laboratory animals. The available
information on the risk of developing
gastrointestinal tract cancer associated
with the ingestion of asbestos from
drinking water is limited. Ingestion of
intermediate-range chrysotile asbestos
fibers greater than 10 micrometers in
length is associated with causing benign
tumors in male rats. Chemicals that
cause cancer in laboratory animals also
may increase the risk of cancer in
humans who are exposed over long
periods of tine. EPA has set the drinking
water standard for asbestos at 7 million
long fibers per liter to reduce the
potential risk of cancer or other adverse
health effects which neve been observed
in laboratory animals. Drinking water
which meets the EPA standard is
associated with little to none of this risk
and should be considered safe with
respect to asbestos.
(16) [Reserved]
(17) Cadmium. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that cadmium is a health
concern at certain levels of e?rposure.
Food and the smoking of tobacco are
common source:; of general exposure.
This inorganic metal is a contaminant in
the metals used to galvanize pipe. It
generally gets ir.tc water by corrosion of
galvanized pipe? or by improper waste
disposal. This cherr.iccl has bsen showr.
to damage the kidney in animals such as
rats and mine when the animals are
exposed el high levels over then-
lifetimes. Some industrial workers who
were exposed to relatively large
amounta of this chemical daring working
careers also suffered darnag? to the
kidney. EPA has SRt the drinking water
standard for cadmium at 0.005 parts per
million (ppm) to protect against the risk
of these adverse health effects. Drinking
water that meets the EPA standard is
associated with little to none of this rial;
and is considered safe with respect to
cadmium.
(18) Chromium. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that chromium is a health
concern at certain levels of exposure.
This inorganic metal occurs naturally in
the ground and is often used in the
electroplating of metals. It generally gets
into water irom runoff from old mining
operations and improper waste disposal
from plating operations. This chemical
has been shown to damage the kidney.
nervous system, end the circulatory
system of laboratory animals such as
rats and mice when the animals are
exposed at high levels. Some humans
who were exposed to nigh levels of this
chemical suffered liver and kidney
damage, dermatitis and respiratory
problems. EPA has set the drinking
water standard for chromium at 0.1
parts per million (ppm) to protect
against the risk of these adverse health
effects. Drinking water that meets the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to chromium.
(19) Mercury. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that mercury is a health
concern at certain levels of exposure.
This inorganic metal is used in electrical
equipment and some water pumps. It
usually gets into water as a result of
improper waste disposal. This chemical
has been shown to damage the kidney of
laboratory animals such as rats when
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358S Foderal KsgiQter / Vol. 56, No. 20 / Wednesday, January 30. 1991 / Rules and Regulations
the animals are exposed at high levels
over their lifetimes. EPA has set the
drinking water standard for mercury at
0.002 parts per million (ppm) to protect
against the risk of these adverse health
effects. Drinking water that meets the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to mercury.
(20) Nitrate. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that nitrate poses an acute
health concern at certain levels of
exposure. Nitrate is used in fertilizer
and is found in sewage and wastes from
human and/or farm animals and
generally gets into drinking water from
those activities. Excessive levels of
nitrate in drinking water have caused
serious illness and sometimes death in
infants under six months of age. The
serious illness in infants is caused
because nitrate is converted to nitrite in
the body. Nitrite interferes with the
oxygen carrying capacity of the child's
blood. This is an acute disease in that
symptoms can develop rapidly in
infants. In most cases, health
deteriorates over a period of days.
Symptoms include shortness of breath
and blueness of the skin. Clearly, expert
medical advice should be sought
immediately if these symptoms occur.
The purpose of this notice is to
encourage parents and other responsible
parties to provide infants with an
alternate source of drinking water. Local
and State health authorities are the best
source for information concerning
alternate sources of drinking water for
infants. EPA has set the drinking water
standard at 10 parts per million (ppm)
for nitrate to protect against the risk of
these adverse effects. EPA has also set a
drinking water standard for nitrite at 1
ppm. To allow for ths fact that the
toxicity of nitrate and nitrite are
additive, EPA has also established a
standard for the sum of nitrate and
nitrite at 10 ppm. Drinking water that
meets the EPA standard is associated
with little to none of this risk and is
considered safe with respect to nitrate.
(21) Nitrite. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that nitrite poses an acute
health concern at certain levels of
exposure. This inorganic chemical is
used in fertilizers and is found in
sewage and wastes from humans and/or
farm animals and generally gets into
drinking water 03 a result of those
activities. While excessive levels of
nitrite in drinking water have not been
observed, other sources of nitrite have
caused oerious illness and sometimes
death in infants under six months of age.
The serious illness in infants is caused
because nitrite interferes with the
oxygen carrying capacity of the child's
blood. This is an acute disease in that
symptoms can develop rapidly.
However, in most cases, health
deteriorates over a period of days.
Symptoms include shortness of breath
end blueness of the skin. Clearly, expert
medical advice should be sought
immediately if these symptoms occur.
The purpose of this notice is to
encourage parents and other responsible
parties to provide infants with an
alternate source of drinking water. Local
and State health authorities are the best
source for information concerning
alternate sources of drinking water for
infants. EPA has set the drinking water
standard at 1 part per million (ppm) for
nitrite to protect against the risk of these
adverse effects. EPA has also set a
drinking water standard for nitrate
(converted to nitrite in humans) at 10
ppm and for the sum of nitrate and
nitrite at 10 ppm. Drinking water that
meets the EPA standard is associated
with little to none of this risk and is
considered safe with respect to nitrite.
(22) Selenium. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that selenium is & health
concern at certain high levels of
exposure. Selenium is also an essential
nutrient at low levels of exposure. This
inorganic chemical is found naturally in
food and soils and is used in electronics.
photocopy operations, the manufacture
of glass, chemicals, drugs, and as a
fungicide and a feed additive. In
humans, exposure to high levels of
selenium over a long period of time has
resulted in a number of adverse health
effects, including a loss of feeling and
control in the arms and legs. EPA has
set the drinking water standard for
selenium at 0.05 parts per million (ppm)
to protect against the risk of these
adverse health effects. Drinking water
that meets the EPA standard is
associated with little to none of this risk
and is considered safe with respect to
selenium.
(23) Acrylamide. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that acrylamide is 0 health
concern at certain levels of exposure.
Polymers made from acrylamide are
sometimes used to treat water supplies
to remove paniculate contaminants.
Acrylamide has been shown to cause
cancer in laboratory animals such 00
rats and mice when the animals are
exposed et high levels over their
lifetimes. Chemicals that cause cancer in
laboratory animals also may increase
the risk of cancer in humans who are
exposed over long periods of time.
Sufficiently large doses of acrylamide
are known to cause neurological injury.
EPA has set the drinking water standard
for acrylamide using a treatment
technique to reduce the risk of cancer or
other adverse health effects which have
been observed in laboratory animals.
This treatment technique limits the
amount of acrylamide in the polymer
and the amount of the polymer which
may be added to drinking water to
remove particulates. Drinking water
systems which comply with this
treatment technique have little to no risk
and are considered safe with respect to
acrylamide.
(2) Ahchlor. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that alachlor is a health
concern at certain levels of exposure.
This organic chemical is a widely used
pesticide. When soil and climatic
conditions are favorable, alachlor may
get into drinking water by runoff into
surface water or by leaching into ground
water. This chemical has been shown to
cause cancer in laboratory animals such
as rats and mice when the animals are
exposed at high levels over their
lifetimes. Chemicals that cause cancer in
laboratory animals also may increase
the risk of cancer in humans who are
exposed over long periods of time. EPA
has set the drinking water standard for
alachlor at 0.002 parts per million (ppm)
to reduce the risk of cancer or other
adverse health effects which have been
observed in laboratory animals.
Drinking water that meets this standard
is associated with little to none of this
risk and is considered safe with respect
to alachlor.
(25) -(27} (Reserved)
(28) Atrazine. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that atrazine is a health
concern at certain levels of exposure.
This organic chemical is a herbicide.
When soil and climatic conditions are
favorable, atrazine may get into drinking
water by runoff into surface water or by
leaching into ground water. This
chemical has been shown to affect
offspring of rats and the heart of dogs.
EPA has set the drinking water standard
for atrazine at 0.003 parts per million
(ppm) to protect against the risk of these
adverse health effects. Drinking water
that meets the EPA standard is
asoociated with little to none of this risk
and is considered ? fe wtih respect to
atrazine.
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Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3588
(29) Carbofuran. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that carbofuran is a health
concern at certain levels of exposure.
This organic chemical is a pesticide.
When soil and climatic conditions are
favorable, carbofuran may get into
drinking water by rur.off into surface
water or by leaching into ground water.
This chemical has been shown to
damage the nervous and reproductive
systems of laboratory cnimais such as
rats and mice exposed at high levels
over their lifetiin?:. Some humans who
were exposed to relatively large
amounts of this chemical during their
working careers ciso suffered damage to
the nervous sysierr.. Effects on the
nervous system are generally rapidly
reversible. EPA bus set the drinking
water standard for carbofuran at 0.04
parts per million (ppm) to protect
ejainst tiie risk of these adverse health
ei'fucts. Drinking water that meets the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to carbofuran.
(30) Chlordane. The United States
Environmental Protection Agency (EPA
sets drinking water standards and has
determined that chlordane is a health
concern at certain levels of exposure.
This organic chemical is a pesticide
used control termites. Chlordane is not
very mobile in soils. It usually gets into
drinking water after application near
water supply intakes or wells. This
chemical has been shown to cause
cancer in laboratory animals such as
rats and mice when the animals are
exposed at high levels over their
lifetimes. Chemicals that cause cancer in
laboratory animals also may increase
the risk of cancer in humans who are
exposed over long periods of time. EPA
has set the drinking water standard for
chlordane at 0.002 parts per million
(ppm) to reduce the risk of cancer or
other adverse health effects which have
been observed in laboratory animals.
Drinking water that meets the EPA
standard is associated with little to none
of this risk and is considered safe with
respect to chlordane.
(31) Dibrorr.ochloropropcne (DBCP).
The United States Environmental
Protection Agency (EPA) sets drinking
water standards and has determined
that DBCP is a health concern at certain
levels of exposure. This organic
chemical was once a popular pesticide.
When soil and climatic conditions are
favorable, dibromochloropropane may
get into drinking water by runoff into
surface water or by leaching into ground
water. This chemical has been shown to
cause cancer in laboratory animals such
as rats and mice when the animals are
exposed at high levels over their
lifetimes. Chemicals that cause cancer in
laboratory animals also may increase
the risk of cancer in humans who are
exposed over long periods of time. EPA
has set the drinking water standard for
DDCP at 0.0002 parts per million (ppm)
to reduce the risk of cancer or other
adverse health effects which have been
observed in laboratory animals.
Drinking water that meets tha EPA
standard is associated with little to none
of this risk and is considered safe with
respect to DBCP.
(32) o-Dichlorobenzene. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that o-dichiorobenzene
is a health concern at certain levels of
exposure. This organic chemical is used
cs a solvent in the production of
pesticides and dyes. It generally gets
into water by improper waste disposal.
This chemical has been shown to
damage the liver, kidney and the biood
ceils of laboratory animals such as rats
and mice exposed to high levels during
their lifetimes. Some industrial workers
who were exposed to relatively large
amounts of this chemical during working
careers also suffered damage to the
liver, nervous system, and circulatory
system. EPA has set the drinking water
standard for o-dichlorobenzene at 0.6
parts per million (ppm) to protect
against the risk of these adverse health
effects. Drinking water that meets the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to o-dichlorobenzene.
(33) cis-1.2-Dichloroethylene. The
United States Environmental Protection
Agency (EPA) establishes drinking
water standards and has determined
that cis-1.2-dichloroethylene is a health
concern at certain levels of exposure.
This organic chemical is used as a
solvent and intermediate in chemical
production. It generally gets into water
by improper waste disposal. This
chemical has been shown to damage the
liver, nervous system, and circulatory
system of laboratory animals such as
rats and mice when exposed at high
levels over their lifetimes. Some humans
who were exposed to relatively large
amounts of this chemical also suffered
damage to the nervous system. EPA has
set the drinking water standard for cis-
1.2-dichloroethylene at 0.07 parts per
million (ppm) to protect against the risk
of these adverse health effects. Drinking
water the meets that EPA standard is
associated with little to none of this risk
and is considered safe with respect to
cis-l,2-dich!oroethylene.
(34) trans-1.2-Dichloroethylene. The
United States Environmental Protectior
Agency (EPA) establishes drinking
water standards and has determined
that trans-1.2-dichloroethv!ene is a
health concern at certain levels of
exposure. This organic chemical is usc^,
as a solvent and intermediate in
chemical production. It generally ge:s
into water by improper waste d:sposs!.
This chemical has been sho'.vr. to
damage the liver, nervous system, and
the circulatory system of laboratory
animals such as rats and mice whe::
exposed at high levels over the::
lifetimes. Some humans who wers
exposed to relatively large amounts of
this chemical also suffered damage tc
the nervous system. EPA has EC:
drinking water standard for trans-1.2-
dichloroethylene at CM parts per million
(ppm) to protect against the riaK of these
adverse health effects. Drinking water
that meets the EPA standard is
associated with little to none cf this risk
and is considered safe wit:, respect to
trans-1.2-dichloroeth) lene.
(35) 1.2-Dichloropropar,e. The United
States Environmental Protection Agency
(EPA) sets drinking water standards sr.d
has determined that 1,2-dichloroprcpanc
is a health concern at certain levels cf
exposure. This organic chemical is used
as a solvent and pesticide. When soil
and climatic conditions are favorable.
1.2-dichloropropane may get into
drinking water by ruroff into surface
water or by leaching into ground water.
It may also get into drinking water
through improper waste disposal. This
chemical has been shown to cause
cancer in laboratory animals such as
rats and mice when the animals are
exposed at high levels over their
lifetimes. Chemicals that cause career ir.
laboratory animals also may increase
the risk of cancer in humans who are
exposed over long periods of time. EPA
has set the drinking water standard for
1,2-dichloropropane at 0.005 parts per
million (ppm) to reduce the risk of
cancer or other adverse health effects
which have been observed in laboratory
animals. Drinking water that mee»s the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to 1,2-dichloropropane.
(36) 2,4-D. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and hes
determined that 2.4-D is a health
concern at certain levels of exposure.
This organic chemical is used as a
herbicide and to control algae in
reservoirs. When soil and climatic
conditions are favorable. 2,4-D may get
into drinking water by runoff into
surface water or by leaching into ground
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3590 Federal Register / Vol. 56. No. 20 / Wednesday, jannary 30. 1991 / Rules and Regulations
water. This chemical has been shown to
damage the liver and kidney of
laboratory animals such as rats exposed
et high levels during their lifetimes.
Some humans who were exposed to
relatively large amounts cf this chemical
also Buffered damage to the nervous
system. EPA has set the drirJcing water
standard for 2,4-D at 0.07 parts per
million (ppm) to protect ngainst tha riak
of these adverse health effects. Drinking
water that meets the ETA standard is
associated with little to none cf this risk
and is considered safe with raapect to
2,4-D.
• (37) Epichlorohydrin. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that epichlorohydrin is a
health concern at certain levels of
exposure. Polymers made from
epichlorohydrin are sometimes used in
the treatment of water supplies as a
flocculent to remove particulates.
Epichlorohydrin generally gets into
drinking water by improper use of these
polymers. This chemical has been
shown to cause cancer in laboratory
animals such as rats and mice when the
animals are exposed at high levels over
their lifetimes. Chemicals that cause
cancer in laboratory animals also may
increase the risk of cancer in humans
who are exposed over long periods of
time. EPA has set the drinking water
standard for epichlorohydrir. using a
treatment technique to reduce the risk of
cancer or other adverse health effects
which have been observed in laboratory
animals. This treatment technique limits
the amount of epichlorohydrin in the
polymer and the amount of the polymer
which may be added to drinking water
as a flocculent to remove participates.
Drinking water systems which comply
with this treatment technique have little
to no risk and ore considered safe with
respect to epichlorohydrin.
(38) Ethylbenzene. Tne United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined ethylbenzene is a health
concern at certain leveb of exposure.
This organic chemical is a major
component of gasoline. It generally gets
into water by improper waste disposal
, or leaking gasoline tanks. This chemical
has been shewn to damage the kidney,
liver, and nervous system of laboratory
animals such as rats exposed to high
levels during their lifetimes. EPA has set
the drinking water standard for
ethylbenzene at 0.7 part per million
(ppm) to protect against the risk of these
adverse health effects. Drinking water
that meets the EPA standard is
associated with little to none of this risk
and is considered safe with respect to
ethylbenzene.
(39) EthyJene dibrcmide (EDE). The
United States Environmental Protection
Agency (EPA) sets drinking water
standards and has determined that EDB .
is a health concern at certain lei-eis of
exposure. This organic chemical was
once a popular pesticide. When soil ar.d
climatic conditions are favorable, EDfl
may get into drinking water by TJX off
into surface water or by leaching into
ground water. This chemical has been
shown to cause cancer in laboratory
animals such as rats and mice when liie
animals are exposed at high levels ever
their lifetimes. Chemicals that causs
cancer in laboratory animals also may
increase the risk of cancer in humans
who are exposed over long periods of
time. EPA has set the drinking water
standard for EDB at O.OOOC5 part per
million (ppm) to reduce the nsk of
cancer or other adverse health effects
which have been observed in laboratory
animals. Drinking water that meets this
standard is associated with little to none
of this risk and is considered safe with
respect to EDB.
(40) Heptachlor. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that heptachlcr is a health
concern at certain levels of exposure.
This organic chemical was once a
popular pesticide. When soil and
climatic conditions are favorable,
heptachlor may get into drinking water
by runoff into surface water or by
leaching into ground water. This
chemical has been shown to cause
cancer in laboratory animals such as
rats and mice when the animals are
exposed at high levels over their
lifetimes. Chemicals that cause cancer in
laboratory animals also may increase
the risk of cancer in humans who are
exposed over long periods of time. EPA
has set the drinking water standards for
beptachlor at 00)004 part per million
(ppm) to reduce the risk of cancer or
other adverse health effects which nave
been observed in laboratory animals.
Drinking water that meets this standard
is associated with little to none of this
risk and is considered safs with respoct
to heptachlor.
(41) Heptachlor epoxide. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that heptechlor epoxide
is a health concern at certain levels cf
eposure. This organic chemical was
once a popular pesticide. When soil and
climatic conditions are favorable,
heptachlor expoxide may get into
drinking water by runoff into surface
water or by leaching into ground water.
This chemical has been shown to cause
cancer in laboratory enimala such as
rsts and mice whsn the animals are
exposed at high ievsia over their
lifetimes. Chemicals that cause cancor in
laboratory animals also may increase
the risk of cancer in humans who are
exposed over long periods cf time. EPA
has set the drinking water standards for
heptachlor epoxide ct 0.0002 part per
million (ppm) to reduca the nsk of
cancer or eiher adverse health effects
which have been observed in laboratory
animals. Drinking water that meets this
standard is associated *.\ith little to none
cf this risk and is considered safe with
respect to heptachlor epoxide.
(42) Lindane. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that licdane is a health
concern at certain levels cf exposure.
Tnis organic chemical ;s used as a
pesticide. When soil end cliraatic
conditions are favorahh, lindane may
get into drinking water by runoff into
surface water or by baching into ground
water. This chemical has bsen shown to
damage the liver, kidney, nervous
system, and immune system of
laboratory animals sucli as rats, mice
and dogs exposed at high levels during
their lifetimes. Some humans who were
exposed to relatively large amounts of
this chemical also suffered damage to
the nervous system and circulatory
system. EPA has established the
drinking water standard for lindane at
0.0002 part per million (ppm) to protect
against the risk of these adverse health
effects. Drinking water that meets the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to lindane.
(43) Methoxychlor. The United States
EnvironmentaJ Protacticn Aae.-.cy (EPA)
sets drinking water standards end has
determined that mcthoxychlor is a
health concern at certain levels of
exposure. This organic chemical is used
as a pesticide. When soil and climatic
conditions are favorable, methoxychlor
may get into drinking water by runoff
into surface water or by leaching into
ground water. This chemical has been
shown to damage the liver, kidney,
nervous system, ar.d reproductive
system of laboratory animals such as
rats exposed at high levels during their
lifetimes. It has alao been shown to
produce growth retardation in rats. EPA
has set the drinking water standard for
methoxychlor at 0.04 part per million
(ppm) to protect against the risk of these
advene health effects. Drinking water
that meets the EPA standard is
associated with little to none of this risk
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Federal Register / Vol. 56, No. 20 / Wednesday, January 30, 1991 / Rules and Regulations 3591
and is considered safe with respect to
methoxychlor.
(44) Monochiorobenzene. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that monochlorobenzene
is a health concern at certain levels of
exposure. This organic chemical is used
as a solvent. It generally gets into water
by improper waste disposal. This
chemical has been shown to damage the
1'ver, kidney and nervous system of
laboratory animals such as rats and
rr.ice exposed to high levels during their
lifetimes. EPA has set the drinking water
standard for monochlorobenznne at 0.1
part per million (ppm) to protect against
the risk of these adverse health effects.
Drinking water that meets the EPA
standard is associated with little to none
of this risk and is considered safe witn
rcsnect to monochlorobensene.
(45) PoirctiJorinaied biD.henv.'s
(PCBs). 1l3 United States
Environmental Protection Acency (EPA)
Sfcts drinking water standards and has
determined ma: polychlorinated
biphenyls (FCBsj are a health concerr. at
certain levels of exposure. These
organic chemicals were once widely
used in electrical transformers and other
industrial equipment. They generally get
into drinking water by improper waste
disposal or leaking electrical industrial
equipment. This chemical has been
shown to cause cancer in laboratory
animals such as rats and mice when the
animals are exposed at high levels over
their lifetimes. Chemicals that cause
cancer in laboratory animals also may
increase the risk of cancer in humans
who are exposed over long periods cf
time. EPA has set the drinking water
standard for PCBs at 0.0005 part per
million (ppm) to reduce the risk of
cancer or other adverse health effects
which have been observed in laboratory
animals. Drinking water that meets this
standard is associated with little to none
of this risk and is considered safe with
respect to PCBs.
(46) [Reserved]
(47) Siyrene. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that styrene is a health
concern et certain levels of exposure.
This organic chemical is commonly used
to make plastics and ia sometimes a
component of resins used for drinking
water treatment. Styrene may get into
drinking water from improper waste
•disposal. This chemical has been shown
to damage the liver and nervous system
in laboratory animals when exposed at
high levels during their lifetimes. EPA
has set the drinking water standard for
styrene at 0.1 part per million (ppm) to
protect against the risk of these adverse
health effects. Drinking water that meets
the EPA standard is associated with
little to none of this risk and is
considered safe with respect to styrene.
(48) Tetrachloroethylene. The United
States Environmental Protection Agcr.cy
(EPA) sets drinking water standards and
has determined that tetrachloroethylene
is a health concern at certain levels of
exposure. This organic chemical has
been a popular solvent, particularly fcr
dry cleaning, it generally gets into
drinking water by improper wast?
disposal. This chemical has been shown
to cause cancer in laboratory animals
such as rats and mice when the animals
ere exposed at high levels ove: their
lifetimes. Chemicals that cause cancer in
laboratory animals also may increase
the risk of cancer in humans wno are
exposed over long periods of time. EPA
has set the drinking water standard for
tetriciiloroethylene at 0.005 part per
mihion (ppm) to reduce the risk of
cancer or o:her adverse heaith effects
which have been observed in laboratory
an:mals. Drinking water that meets this
standard is associated wi'.h little to none
of this risk and is considered safe with
respect to tetrachloroethylene.
(49) Toluene. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that toluene is a health
concern at certain levels of exposure.
This organic chemical is used as a
solvent and in the manufacture of
gasoline for airplanes. It generally gets
into water by improper waste disposal
or leaking underground storage tanks.
This chemical has been shown to
damage the kidney, nervous system, and
circulatory system of laboratory animals
such as rats and mice exposed to high
levels during their lifetimes. Some
industrial workers who were exposed to
relatively large amounts of this chemical
during working careers also suffered
damage to the liver, kidney and nervous
system. EPA has set the drinking water
standard for toluene at 1 part per million
(ppm) to protect against the risk of
adverse health effects. Drinking water
that meets the EPA standard is
associated with little to none of this risk
and is considered safe with respect to
toluene.
(50) Toxaphene. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that toxaphene is a health
concern at certain levels of exposure.
This organic chemical was once a
pesticide widely used on cotton, corn,
soybeans, pineapples and other crops.
When soil and climatic conditions are
favorable, toxaphene may get into
drinking water by runoff into surface
water or by leaching into ground water.
This chemical has been shown to cause
cancer in laboratory animals such as
rats and mice when the animals are
exposed at high levels over their
lifetimes. Chemicals that cause cancer i->
laboratory animals also may increase
the risk of cancer in hurr.ans who are
exposed over long periods of f.me. EPA
has set the drinking water standaid for
toxaphcne ai 0.003 p=rt per miilior.
(ppm) to reduce the risk cf cancer or
other adverse health effects which have
been observed in laboratory animals.
Drinking water that meets this standard
is associated with lit'.ie to r.cr? of this
risk ar.d is considered safe \\~\t\ resper.:
to toxaphene.
(5i) 2.4.5-TP. The united State:-
Environmental Protection Aeency (EPA;
sets drir.kinp water standards and has
determined that 2.4.5-TP is a health
concern at certain levels of exposure-.
This organic chemical is uses as a
herbicide. When sail and ciimai;;-
conditions are favorable. 2.4.5-TP mey
get into drinking wa'.er by rur.off ir.tr.
surface water or by leaching ir.to ground
water. This chemical has been shown to
damage the liver and kidney cf
laboratory animals such as rats and
dogs exposed to high levels during their
lifetimes. Some industrial workers who
were exposed to relatively large
amounts of this chemical during working
careers also suffered damage to the
nervous system. EPA has set the
drinking water standard for 2.4.5-TP at
0.05 part per million (ppm) to protect
against the risk of these adverse health
effects. Drinking water that meets the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to 2.4.5-TP.
(52) Xylenes. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that xylene is a health
concern at certain levels of exposure.
This organic chemical is used in the
manufacture of gasoline for airplanes
ar.d as a solvent for pesticides, and as a
cleaner and degreaser cf metals. It
usually gets into water by improper
waste disposal. This chemical has been
shown to damage the liver, kidney and
nervous system of laboratory animals
such as rats and dogs exposed tc high
levels during their lifetimes. Some
humans who were exposed to relatively
large amounts of this chemical also
suffered damage to the nervous system.
EPA has set the drinking water standard
for xylene at 10 parts per million (ppm)
to protect against the risk cf these
adverse health effects. Drinking water
that meets the EPA standard is
associated with little to none of this risk
-------
352)2
/ Vol. 56. No. 20 / Wednesday. January 30. 1591 / Rules and Regulations
end is considered safe with respect to
yylene.
7. In § 141.40 the section heading is
revised and a new paragraph (n) is
added to read as follows:
§ 141.40 Soocla! monltcTtng for Inorganic
and organic chomJcoio.
o ft « ft ft
(n) Monitoring of the contaminants
listed in § 141.40(n) (11) and (12) shall be
conducted as follows:
('() Each community a ad non-
transient non-community water system
shall take four consecutive quarterly
samples a; each sampling point for each
contaminant listed in paragraph (c)(ll)
GV this section end report the results to
the State. Monitoring must be completed
by December 31.1S95.
(2) Each community and non-transient
non-community water system shall take
one sample at each sampling point for
each contaminant listed in paragraph
(n)(i2) of this section and report the
resets to the States. Monitoring must be
completed by December 31,1995.
(3) Each community and non-transient
non-community water system may apply
to the State for a waiver from the
requirements of paragraph (n) (1) and (2)
of this section.
(4) The State may grant a waiver for
the requirement of paragraph (n)(l) of
this section based on the criteria
specified in § 141.24(h)(8). The State
may grant a waiver from the
requirement of paragraph (n){2) of thio
section if previous analytical results
indicate contamination would not occur.
provided this data was collected after
January 1.1990.
(5) Croundwater systems ohall take a
minimum cf one sample at every entry
point to the diotribution oystem which is
representative of each well after
treatment (hereafter called a campling
point). Each sample muci be taken at the
same sampling point unless conditions
make another campling point more
representative of each source or
treatment plant.
(6) Surface water systems shall take a
minimum cf one cample at pointo in the
distribution system that ore
representative of each source or at each
entry pouit to the distribution system
aUer treatment (hereafter called &
sampling point). Each sample must be
taken at the same sampling point unless
conditions make another sampling point
more representative of each source or
treatment plant.
Note): For purpocso of thio paragraph.
surface water oyotemo induda oystemo with a
combination of ourface and ground courceo.
(7) If the system draws water from
more than one source and the sources
are combined before distribution, the
i system must sample at an entry point to
the distribution system during periods of
' normal operating conditions (i.e.. when
I water rspresentative of all sources is
i being used).
! (8) The State may require a
| confirmation sample for positive cr
' negative results.
I (9) The State may reduce the total
I number of samples a system must
I analyze by allowing the use of
I compositing. Composite samples from a
i maximum of five sampling points arc
I allowed. Compositing of samples must
i be done in the laboratory and the
composite sample must be analyzed
within 14 days of collection. If the
population served by the system is
> 3,300 persons, then compositing may
only be permitted by the State at
sampling points within a single system.
In systems serving < 3,300 persons, the
State may permit compositing among
different systems provided the 5-sample
limit is maintained.
(10) Instead of performing the
monitoring required by this section, a
community water system or non-
transient non-community water system
serving fewer than 150 service
connections may send a letter to the
State stating that the system is available
for sampling. This letter must bs sent to
the State by January 1,1S34. The system
shall not send such samples to the State.
unleso requested to do so by the State.
(11) Lict of Unregulated Organic
Contaminants:
Contonunont
EPA analytical method
Onjortc contcfiKnento
Akfrm _
BcrtsDlQto
B jtacKor
Cartinrtd
Oolopon _.« -
Dscomba.-
Dietirin -
Dinocoto ______
DlQUQt ___
EretoOidl
GlyphooaG
Hauichiorobsnzara
HosachtaceycloponlsxlJeno..
S-MytfroKycarSofuran
Mototacfto .
F'dorom
Propschtor
Sinwms
2,3.7.8-TCDO (Koran) —
EPA analytics1
resetted
SS3. 903. 525
323. 950. 550.1
507,535
531.1
513.1
503.523
503, S25
313.1
SOS. 503. S25
515.1
548
340
547
505.308. 525
505.535
531.1
531.1
307.323
507, SOS. 523
531.1
515.1
507. 325
303. 307. 323
313
(12) List of Unregalated Inorganic
Contaminants:
(i) Antimony
(;i) BwyU-um
(iii) PJickel
(iv) Sultata
(v) Thallium
(vi) Cyarute
Grocftrte Furraco Atomic Ab-
corpten; IrnfucSvelv Cou-
(&x) Plasma.
Grcptuta Fumcea Atoms: Ab-
sorption: Inductively Cou-
pled P/.ass Spctiioniady
PtaStno: Spcctroonotonts-
tro.
Atomic AbEcrpJjorv Inductive-
ly Coupled Piasma: Graph-
ite FUTTUICQ Atomic Absorp-
tion.
Coionrne&tc.
GrepJots Fumsca Aiorrec .V)-
sorpaon: Inductively Ccu-
pltd Mass Spsdrometvy
I
8. Section 141.50 is amended in the
table by adding paragraphs (a)(0)
through (a)(14), reserving (a)(15), adding
(a)(16) through (e)118), reserving (b)(4)
L-irough (b)(6). and adding (b)(7) through
(20) to read as follows:
§ 1 -8 1.50 Klaataura eomtares!naf»8 IGWO!
goolo for organic ehoraSenta.
(a) • • •
(6) Acryiamide
(7) Alachlor
(8) Chlordane
(9) Dibromochlorcpropane
(10) l^-Dichloropropans
(11) Epichlorohydrin
(12) Ethylene dibromide
(13) Heptachlor
(14) Heptachlor epoxide
(15) [Reserved]
(16) Polychlorinated biphenyls (PCBs)
(17) Tetrachloroelhylene
(13) Toxaphene
(b) • • •
WCLG
(<)-!6) [Rsosrvcd]
(7) Atraa.T3
(8) Corbofuran.
O.C03
0.04
(9) o-DichJorobanzona..- 0.6
(10) ci3-1.2-DictaJJX»»vytena C.07
(12) 2.4-0 0.07
(13) EUrylfcanzons __._ 0.7
(14) Lindano 0.0002
(15) MQthcKVtfitor C.04
(17) Styrcro 0.1
(18) TeSuorco 1
(19) 2,4,5-TP _ _ - 0.05
(20) Xytarea (total) _ 10
0. Section 141.51 is amended in the
table by adding (b)(2), reserving (b)(3).
adding (b) (4) through (9) and revising
the heading for the second column to
read as followo:
-------
Fedacal Register / VoL 58. No. 20 / Wadnesday. lamutry 30. 1991 / Bates aaA Bagulateona 3593
$ 141.51 Maximum contaminant Mnul
goals for Inorganic contaminant*.
(b) * ' •
Contaminant
MC5.G tmg/l)
(2) Asbesto».- 7 Million libers/liter
(longer than 10 »irr,).
(3) (Reserved)
W Cadmium 0.005
(5) Chronuum_ 0.1
(6) Mercury O.OC2
(7) Nitrtte 10 (as Nitrogen)
(8) Nitme 1 (as Nitrogen).
(9) Tata) Niinte-t Nitrite.. 10 (aa Ntrogen).
(10) Selenium 0.05
10.Section 141.60-ie reviaedto-tead as
follows:
$14t.60 Effective data*.
(a) The effective dates for { 141.61 are
as follows:
(1) The effective date for paragraphs
(a)(l) through (a)(B}of 5 141.61 is
January B. 1989.
(2) The effective date for paragraphs
(a)(9) through (a)fI8) and (cj(l) through
(c)(18) of $ 141.61 is July 30, 1992.
(b) The effective dates for § 141.62 are
as follows:
(1) The effective date of paragraph
(b)(l) of § 141.62 is October 2.1987.
(2) The effective date for paragraphs
(b){2) and (b)(4) through (b)(10) of
5 141.62 is July 30.1992.
11. Section 141.61 is revised to read as
follows:
irtamtnant tavot* (or
} Ht.61 Maximum co
organic contaminants.
(a) The- following maximum
contaminant levels for organic
contaminants apply to community and
non-transient, non-community water
systems.
CAS No.
(1) 75-01-4 _.
(2) 71-43-2 _
(3) 56-23-5
(4) 107-06-2
(5) 79-01-6 .
(6) 106-48-7
(7) 75r35-4.
(8) 71-SS-fi
(9) 156-5S-2
(10) 78-87-5...
(11) 100-4.1-4.
(12) 1 08-00-7 _
(13) B5-5O-1
(14) 100-42-5
(15) 127- 18-4
(16) 108-88-3
(17) 156-60-5
(18) 1330-2O-7 _ . .
r*J«a^*flB^»^M*
ixji i w i BI vro
Vinyl cMorida
Benzene
Carbon tatraonlofide _.._.-...,
1 2-OieMO'Gfrtnaf1*,-. . .. .- .,-
Tnehloroethy4ene_
para Ptcnlof obamano _.-._...,
1 1-QitniotiKtnyimi _. ,._
1 1 1-Trichlnfo»tn«rm
cit-lji-rjiGnloroetnytene ,
1 J-DicNQfopfopane ..-- ^">
FtrnlhenraM
Monoctilorobenxpne •.•
o-DichlorotMnzarM — ._ " •
Slyfene -
Totrechtoroethytane. . ..«»... -...
Toluene ,,^,..., _....,„
Xylenes (total) . - - - — — ™
MCL 01 both as
the best technology, treatment
technique, or other means available for
achieving compliance with the
maximum contaminant level for organic
contaminants identified in paragraphs
(a) and (c) of thi» section:
BAT FOR ORGANIC CONTAMINANTS LISTED IN SECTION 141.61 (a) AND (c)
CAS No.
CtMrncal
QAC
PTA
Alachtof-
AluXailj-
Atn
Benzene—
Cartioturan.
Carbon tanacnloride.
CnloTOeinv
78-67-5...
106-03-4.
100-41-4.
76-44-8.
d»-1.2-DKihtocoetriytena
trana-IJ-Oichtefaettiylena.-
1 .l-Olctitaraethytane
1 ^OtcMoroproDene..
Biiyten»MM»nMe (EOBI...
EthytMnzene
HeptacMor»«...»«.»«.
HeptaeMor epowJe..
72-43-5 _..
106-90-7.
87-66-5.
-------
3594
Federal Register / Vol. 56, No. 20 / Wednesday, January 30. 1991 / Rules and Regulations
BAT FOR ORGANIC CONTAMINANTS LISTED IN SECTION 141.61 (a) AND (c)—Continued
CAS No.
100-42-6
93-72-1
127-18-4 ._ ,
71-55-6
79-01-6
108-88-3 _ _ __
8001-35-2 _ _
75-01-4 „
1330-20-7 ._
Chemical
Styrene... _
2 4 5-TP (Silvex) . . _ -
Tetrachforoethytone .. . -
1 1 1-Trichloroethane
Trichloroetnytene _ _
Toluene —
Toxaphene
Vinyl chloride
Xylene
GAC
X
X
X
X
X
X
X
X
PTA
x
X
X
X
x
x
x
(c) The following maximum
contaminant levels for organic
contaminants apply to community water
systems and non-transient, non-
community water systems.
CAS No.
(1) 15972-«0-a.._ .._ __
(3) .
(4) _ _
(5) 1912-94-fi
(6) 1563-6A-2. -_ ... _ „
(7) 57-74-0 . . _
(8)96-12-8... ._ _ ._.
(9) 84-75-7 _...
(10) 100-03-4
(11) 7B-H-* ,
(12) 1024-57-3
(19) SB-B9-9 , , ,
(14) 72-43-5
(15) 133B-3B-3
(16).
(17) B001-.1S-J ,
(18) 83-72-1
Contaminant
Alachlor . _
[Reaerved]
[Reserved]
Reserved]
AtreZine . .. .. ....„—-,.,,.. r,r....r-, --,,.
Cartjofufan .....
DibfornocnloropTOpane
Ethytene dibromide _ .
Heptachlor . - - . -
Heptachlor epoxide
I bvtaiM
Methoiythkx — — .
[Reserved]
2.4.5-TP
MCL (mg/l)
0002
0.003
004
0.0002
0.07
0.00005
0.0004
0.0002
0.0002
0.04
00005
0.003
0.05
12. Section 141.62 is revised to read as
follows:
9 141.62 Maximum contaminant level* for
Inorganic contaminant*.
(a) [Reserved]
(b) The maximum contaminant levels
for inorganic contaminants specified in
paragraphs (b)(2) through (6) and (b)(10)
of this section apply to community
water systems and non-transient, non-
community water systems. The
Maximum Contaminant Level specified
in paragraph (b)(l) of this section only
applies to community water systems.
The Maximum Contaminant Levels
specified in paragraphs fb)(7), (b)(8), and
(b)(9) of this section apply to
community, non-transient non-
community, and transient non-
community water systems.
MCL (mo/I)
(1) Fluoride
(2) Asbestos...—
(3) [Reserved]
(4) Cefrmrum
(5) Chromium
(8) Mercury
(7) Nitrate
(8) Nitrite
4
7 Million Fibers/liter
(longer than 10 pm).
0.005
0.1
0.002
10 (aa Nitrogen)
1 (as Nitrogen)
Contaminant
(9) Total Nitrate and
Nitrite.
(10) Selenium
MCL (mg/l)
10 (as Nitrogen)
0.05
(c) The Administrator, pursuant to
section 1412 of the Act. hereby identifies
the following as the best technology,
treatment technique, or other means
available for achieving compliance with
the maximum contaminant level for
inorganic contaminants identified in
paragraph (b) of this section, except
fluoride:
BAT FOR INORGANIC CONTAMINANTS
LISTED IN §141.62(b)
Chemical name
BAT(«)
Attmtot , ,, ,
Barium »..„.„«..«
Cadmium ...«.........»»_..™-.—....._
Mercury _
Nitrate .
Nitrite _______
Selenium _
23,8
5.6.7.9
2.5.6.7
2,5.6 «.7
2 '.4.6 '.7 •
5.7.9
5.7
1.2 '.6.7.9
• BAT lor Chromium III only.
• BAT tor Selenium IV only.
Key to BATi In Table:
1 - Activated Alumina
2 - Coagulation/Filtration
3 - Direct and DJatomrte Filtration
4 - Granular Activated Carbon
5 —s Ion Exchange
6 - Lime Softening
7 » Reverse Osmosis
8 •= Corrosion Control
9 - Etoctrodialysis
13. A new subpari K is added to part
141 to read as follows:
Subpart K—Treatment Techniques
Sec.
141.110 General requirements.
141.111 Treatment techniques for
acrylamide and epichlorohydrin.
Subpart K—Treatment Techniques
§141.110 Genera) requlrementa.
The requirements of subpart K of this
part constitute national primary drinking
water regulations. These regulations
establish treatment techniques in lieu of
maximum contaminant levels for
specified contaminants.
9 141.111 Treatment techniques for
acrylamide and •plcnlorohydrln.
Each public water system must certify
annually in writing to the State (using
third party or manufacturer's
certification) that when acrylamide and
epichlorohydrin are used in drinking
-------
Federal Register / Vol. 56, No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3595
water systems, the combination (or
product) of dose and monomer level
does not exceed the levels specified as
follows:
1 Acrylamide=0.05% dosed at 1 ppm (or
equivalent]
Epichlorohydrin=0.01% dosed al 20 ppm (or
equivalent)
Certifications can rely on manufacturers
or third parties, as approved by the
State.
PART 142—NATIONAL PRIMARY
DRINKING WATER REGULATIONS
IMPLEMENTATION
1. The authority citation for part 142
continues to read as follows:
Authority: 42 U.S.C. 300s. 300g-l. 300g-2.
300g-3, 300g-4. 300g-5. 300g-6. 300|-4 and
300J-9.
2. Section 142.14 is amended by
revising paragraph (a)(6). paragraph (c),
the introductory text to paragraph (d).
and paragraph (f); and by adding
paragraphs (d)(4) through (djl?) to read
as follows:
§ 142.14 Record* kept by States.
(a) • ' '
(0) Records of analysis for other than
microbiological contaminants (including
total coliform, fecal coliform. and
heterotrophic plate count), residual
disinfectant concentration, other
Parameters necessary to determine
plisinfection effectiveness (including
temperature and pH measurements).
end turbidity shall be retained for not
less than 12 years and shall include at
least the following information:
* * • • •
(c) Each State which has primary
enforcement responsibility shall
maintain current inventory information
for every public water system in the
State and shall retain inventory records
of public water systems for not less than
12 years.
(d) Each State which has primary
enforcement responsibility shall retain,
for not less than 12 years, files which
shall include for each such public water
system in the State:
• • • • •
(4) A record of the most recent
vulnerability determination, including
the monitoring results and other data
supporting the determination, the State's
findings based on tne supporting data
and any additional bases for such
determination: except that it shall be
kept in perpetuity or until a more current
vulnerability determination has been
issued.
(5) A record of all current monitoring
•uuirements and the most recent
Knitoring frequency decision
pertaining to each contaminant,
including the monitoring results and
other data supporting the decision, the
State's findings based on the supporting
data and any additional bases for such
decision; except that the record shall be
kept in perpetuity or until a more recent
monitoring frequency decision has been
issued.
(6) A record of the most recent
asbestos repeat monitoring
determination, including the monitoring
results and other data supporting the
determination, the State's findings based
on the supporting data and any
additional bases for the determination
and the repeat monitoring frequency:
except that these records shall be
maintained in perpetuity or until a more
current repeat monitoring determination
has been issued.
(7) Records of annual certifications
received from systems pursuant to part
141, subpart K demonstrating the
system's compliance with the treatmen!
techniques for acrylamide and/or
epichlorohydrin in § 14.111.
• • • * •
(f) Records required to be kept under
this section shall be available to the
Regional Administrator upon request.
The records required to be kept under
this section shall be maintained and
made available for public inspection by
the State, or. the State at its option may
require suppliers of water to make
available for public inspection those
records maintained in accordance with
§ 141.33
3. In § 142.15 is amended by adding
new paragraph (c)(3) to read as follows:
§ 142.15 Report* by States.
• * • • •
(c) ' * '
(3) The results of monitoring for
unregulated contaminants shall be
reported quarterly.
4. § 142.16 is amended by reserving
paragraph (d) and by adding a new
paragraph (e) to read as follows:
§ 142.16 Special primacy requirements.
• • • * •
(d) [Reserved]
(e) An application for approval of a
State program revision which adopts the
requirements specified in §§ 141.23,
141.24, 141.32, 141.40, 141.61, 141.62, and
141.11 must contain the following (in
addition to the general primacy
requirements enumerated elsewhere in
this part, including the requirement that
state regulations be at least as stringent
as the federal requirements):
(1) If a State chooses to issue waivers
from the monitoring requirements in
J5 141.23.141.24. and 141.40. the State
shall describe the procedures and
criteria which it will use to review
waiver applications and issue waiver
determinations.
(i) The procedures for each
contaminant or class of contamina its
shall include a description of:
(A) The waiver application
requirements:
(B) The Slate review process for 'use"
waivers and for "susceptibility"
waivers; and
(C) The State decision criteria.
including the factors that will be
considered in deciding to grant or deny
waivers. The decision criteria must
include the factors specified in
§§ 141.24(f)(8), 141.24(h)(6). and
141.40(n)(4).
(ii) The State must specify the
monitoring data and other
documentation required to demonstrate
that the contaminant is eligible for a
"use" and/or "susceptibility" waiver.
(2) A plan for the initial morJtoring
period within which the Slate will
assure that all systems complete the
required monitoring by the regulatory
deadlines;
(i) The plan must describe how-
systems will be scheduled during the
initial monitoring period and
demonstrate that the analytical
workload on certified laboratories for
each of the three years has been taken
into account, to assure that the State's
plan will result in a high degree of
monitoring compliance and will be
updated as necessary.
(ii) The State must demonstrate that
the initial plan is enforceable under
State law.
5. Section 142.16 is added to subparl B
to read as follows:
§ 142.18 EPA review of State monitoring
determination*.
(a) A Regional Administrator may
annul a State monitoring determination
for the types of determinations
identified in §§ 141.23(b). 141.23(c),
141.24{f). 141.24(h). and 141.40(n) in
accordance with the procedures in
paragraph (b) of this section.
(b) When information available to a
Regional Administrator, such as the
results of an annual review, indicate a
State determination fails to apply the
standards of the approved State
program, he may propose to annul the
State monitoring determination by
sending the State and the affected PWS
a draft Rescission Order. The draft order
shall:
(1) Identify the PWS, the State
determination, and the provisions at
issue;
-------
Fa&esal Risgiste? / Vol. 56, No. 20 / Wednesday, January 30, 1991 / Rules and Regulafrtens
(2) Explain why the State
determination is not in compliance with
the State program and must be changed;
and
(3) Describe the actions and terms of
operation the PWS will be required to
implement.
(c) The State and PWS shall have SO
days to comment on the draft Rescission
Order.
(d) The Regional Administrator may
not issue a Rescission Order to impose
conditions less stringent than those
imposed by the State.
(e) The Regional Administrator shall
also provide an opportunity for
comment upon the draft Rescission
Order, by
(1) Publishing a notice in a newspaper
in general circulation in communities
served by the affected system: and
(2) Providing 30 days for public
comment on the draft order.
(f) The State shall demonstrate that
the determination is reasonable, based
on its approved State program.
(g) The Regional Administrator shall
decide within 120 days after issuance of
the draft Rescission Order to:
(1) Issue the Rescission Order as
drafted:
(2) Issue a modified Rescission Order
or
(3) Cancal the Rescission Order.
(h) The Regional Administrator shall
set forth the reasons for his decision,
including a responsiveness summary
addressing signincant comments from
the State, the PWS nnd the public.
(i) The Regional Administrator shall
send a noiice of his fins! decision to the
Siate. the PWS er.d all parties who
commented upon the draft Rescission
Order.
0) The Rescission Order shall remain
in effect until cancelled by the Regional
Administrator. The Regional
Administrator may cancel a Rescission
Order at any time. oo long as he notifies
those who commented on the draft
order.
(k) The Ragional Administrator may
not delegate the signature authority for a
final Rescission Order or the
cancellation of an order.
(1) Violation of the actions, or terms of
operation, required by a Rescission
Order is a violation of the Safe Drinking
Water Act.
6. Section 142.57 ia revised to read as
follows:
§ 1C2UI7 EotUos) trotter,
polni-af
(15) TetrceftteroaBvylerta
(16) Toluorta
(17) trans-I.Z-Dichtorosthy-
lano.
(18) Xy:enos (IcJaJ)
(19) Alachlof
(20) Aklicart)
(21) Aldicob eutoiotfa.
(22) Aldicarb sutfona
(23) Atranne .
(24) Carbofuran
(25) Chlordana
(26) Dibromochkxopropana —
(27) 2 4-D
(28) Echy&no (bbroraicti
(29) HeotQCfilor
(30) Hcptcchld opooao
(31) Undcno
(52) MelhoitycWOT
(33) PCBo
(34) PcntccrucrpncrKW
(35) Toxapnervs
(36)2.4.5-TP
B€31 ovBtiabto
Packed
tewcf
Dcrcaan
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Granular
cccvotcd
cotton
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
JC
X
X
X
X
&
X
X
X
identifies the following as the best
technology, treatment techniques, or
other means available for achievin^
compliance with the maximum
contaminant levels for the inorganic
contaminants listed in § 141.82:
BAT FOR INORGANIC COMPOUNDS LISTED
IN §141.62
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Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Rules and Regulations 3597
(f) The State may require a public
water system to use bottled water,
point-of-usfi devices, point-of-entry
devices or other means as a condition of
granting a variance or an exemption
from the requirements of § 141.61 (a)
and (c) and § 141.62 to avoid an
unreasonable risk to health.
(g) Public water systems that use
bottled water as a condition for
receiving a variance or an exemption
from the requirements of § 141.61 (a)
end (c) and $ 141.62 must meet the
requirements specified in either
paragraph (g)(l) or (g)(2) and paragraph
(g)(3) of this section:
(1) The Administiator or primacy
State must require and approve a
monitoring program for bottled water.
The public water system must develop
and put in place a monitoring program
that provides reasonable assurances
that the bottled water meets all MCLs.
The public water system must monitor a
representative sample of the bottled
waier for all contaminants regulated
under § 141.61 (a) and (c) and § 141.62
during the first three rr.ontn period that
it supplies the bottled water to the
public, and annually thereafter. Results
of the monitoring program shall be
provided to the State annually.
(2) The public water system must
receive a certification from the bottled
water company that the bottled water
supplied has been taken from an
"approved source" as defined in 21 CFR
129.3(a); the bottled water company has
conducted monitoring in accordance
with 21 CFR 129J80(g) (1) through (3);
and the bottled water does not exceed
any MCLs or quality limits as set out in
21 CFR 103.35. 110, and 123. The public
water system shall provide the
certification to the State the first quarter
after it supplies bottled water and
annually thereafter. At the State's option
a public water system may satisfy the
requirements of this subsection if an
approved monitoring program is already
in place in another State.
(3) The public water system is fully
responsible for the provision of
sufficient quantities of bottled water to
every person supplied by the public
water system via door-to-door bottled
water delivery.
(h) Public water systems that use
point-of-use or point-of-entry devices as
a condition for obtaining a variance or
an exemption from NPDWRs must meet
the following requirements:
(1) it is the responsibility of the public
water system to operate and maintain
the point-of-use and/or point-of-entry
treatment system.
(2) Before point-of-use or point-of-
entry devices are installed, the public
water system must obtain the approval
of a monitoring plan which ensures that
the devices provide health protection
equivalent to that provided by central
water treatment.
(3) The public water system must
apply effective technology under a
State-approved plan. The
microbiological safety of the water must
be maintained at all times.
(4) The State must require adequate
certification of performance, field
testing, and, if not included in the
certification process, a rigorous
engineering design review of the point-
of-use and/or point-of-entry devices.
(5) The design and application of the
point-of-use and/or point-of-entry
devices must consider the potential for
increasing concentrations of
heterotrophic bacteria in water treated
with activated carbon. It may be
necessary to use frequent backwashing.
post-cor.lac'.or disinfection, and
Heterctrophic Plate Count monitoring to
ensure that the microbiological safety cf
the water is not compromised.
(6) The Mate must be assured th,~t
buildings connected to the system have
sufficient point-of-use or point-of-entry
devices that are properly installed,
maintained, and monitored such that al!
consumers will be protected.
PART 143—NATIONAL SECONDARY
DRINKING WATER REGULATIONS
1. The authority citation for part 143
continues to read as follows:
Authority: 42 U.S.C. 300g-l(c). 300J-4, and
300J-9
2. In § 143.3 the table is revised to
read as follows:
$ 143.3 Secondary maximum contaminant
levels.
ConiBTiinant
Level
Aluminum \ 0.05 to 0.2 mg/1.
Chloride I 250 mQ.'l.
15 color units.
1.0 mg/1.
Color
Copper
CorrosMry I Non-corrosive.
Fluonae 2.0 mg/ i.
Foaming agents | 0.5 mg/1.
Iron ! 0.3 mg/1.
Manganese I 0.05 mg/1.
PH
S-S
Sul
Toi
(
Zinc
or
ate
al dissolved
rOS).
c
solids
I
3 threshold odor
number.
6.5-fl.S.
0.1 mg/1.
250 mg/1.
500 mg/1.
5 mg/1.
$ 143.4 Monitoring.
**»-!•
(b); • •
(12) Aluminum—Method ' 202.1
Atomic Absorption Technique-Direct
Aspiration: or Method 2 303C; or
Method 3 I-305i-B4: or Method ' 202.2
Atomic Absorption-Graphite Furnace
Technique: or Method 2 304: or Method '
200.7 Inductively-Coupled Plasma
Technique: or Method * 200.8
Inductively Coupled Plasma-Mass
Spectrometry or Method • 200.9 Platform
Technique; or Method 7 3120D
Inductively-Coupled Plasma Technique.
(13) Silver—Method ' 272.1 Atomic
Absorption Technique-Direct
Aspiration; or Method 2 303 A or B; or
Method 3 1-3720-64: or Method ' 272.2
Atomic Absorption-Graphite Furnace
Technique: or Method - 304; or Method *
200.7 Inductively-Coupled Plasma-
Technique: or Method 5 200.6
Inductively-Coupled Plasma-Mass
Spectrometry: or Method • 200.9
Platform Technique: or Metnod "' 312OB
Inductively-Coupled Plasma-Technique.
(FR Doc. 91-933 Filed 1-29-91: 8:45 am)
BILLING CODE
3. Section 143.4 is amended by adding
paragraphs (b)(12) and (bj(13) to read as
follows:
' "Methods of Chemical Analvau of Water and
Wastes." EPA. Environmental Monitoring and
Systems Laboratory. Cincinnati. OH 45208. EPA
600/4-79-020. March. 1983. Available from ORD
Publication. CEKJ. EPA. Cincinnati. OH 45268.
1 "Standard Methods for the Examination of
Water and Wastewater." 16th Ed.. American. Public
Health Association. American Waterworks
Association. Water Pollution Control Federation.
1985.
9 "Methods for the Determination of Lnorgan.c
Substances in Water and Fluvial Sediments."
Techniques of Water-Resources Investigations of
the United Slates Geological Survey Books. Chapter
Al. 1985. Available from Ooen File Services
Section. Western Distribution Branch. U.S.
Geological Survey. Denver Federal Center. Denver.
CO BOiSS.
• "Determination of Metals and Trace Elements
by Inductively Coupled Plasma-Atomic Emission
Spectrometry." Metnod 200.7. version 3.1. April.
1990. EPA. Environmental Monitoring and Systems
Laboratory. Cincinnati. OH 45268.
• "Determination of and Trace Elements in Water
and Wastes by Inductively Coupled Plasma-Mass
Specrrometry." Method 200.8. version 4.1. March.
1990. EPA. Environmental Monitoring and Systems
Laboratory. Cincinnati. OH 45268. Available from
ORD Publication. CERI. EPA. Cincinnati. OH 45206
• "Determination of Metals and Trace Elements
by Stabilized Temperature Graphite Furnace
Atomic Absorption Spectromerry." Method 200.9.
version 1.0. April. 1990. EPA. Environmental
Monitoring and Systems Laboratory. Cincinnati. OH
4SZ68.
1 "Standard Methods for the Examination of
Water and Wastewater." 18th ed.. American Public
Health Association. American Waterworks
Association. Water Pollution Control Federation.
1965.
-------
Wednesday
•January 30, 1991
Part III
Environmental
Protection Agency
40 CFR Parts 141 and 142
National Primary Drinking Water
Regulations; Proposed Rule
-------
3600
Federal Register / Vol. 56, No. 20 / Wednesday, January 30, 1991 / Proposed Rules
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Parts 141 and 142
JFRL-3831-6]
National Primary Drinking Water
Regulations—Monitoring for Synthetic
Organic Chemicals; MCLGs and MCLs
for Aldicarb, Aldicarb Sulfoxide,
Aldicarb Sulfone, Pentachlorophenol,
and Barium
AGENCY: Environmental Protection
Agency (EPA).
ACTION: Proposed rule.
SUMMARY: In this document, EPA is
proposing revisions to monitoring
requirements for the eight volatile
organic contaminants (VOCs)
promulgated July 8,1987. This change
would synchronize requirements for the
eight VOCs with those promulgated
elsewhere in today's Federal Register.
EPA is also reproposing the MCLGs and
MCLs for aldicarb, aldicarb sulfoxide,
aldicarb sulfone. pentachlorophenol.
and barium.
DATES: Written comments must be
submitted by March 18,1991.
ADDRESSES: Send written comments on
the proposed rule to VOC/Aldicarb
Comment Clerk, Criteria and Standards
Division, Office of Drinking Water
(WH-550D), Environmental Protection
Agency, 401 M Street, SW., Washington,
DC 20460. Commenters are requested to
submit any references cited in their
comments. Commenters are also-
requested to submit one original and
three copies of their written comments.
Commenters who wish to receive
acknowledgment of their comments
should include a self-addressed stamped
envelope. A copy of the supporting
documents are available for review at
the EPA. Drinking Water Docket, 401 M
Street. SW., Washington. DC 20460. For
access to the docket materials, call 202-
382-3027 between 9:00 a.m. and 3:30 p.m.
FOR FURTHER INFORMATION CONTACT:
Al Havinga, Criteria and Standards
Division, Office of Drinking Water
(WH-550). U.S. Environmental
Protection Agency, 401 M Street, SW..
Washington, DC 20460, 202/382-5555.
General information may also be
obtained from the EPA Drinking Water
Hotline. The toll-free number is 800/426-
4791, Alaska and local: 202/382-5533.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Statutory Authority
II. Regulatory Backgroun
III. Explanation of Today's Action
A. VOC Monitoring Requirements
1. Standa 'dized Monitoring Framework
2. Three-. Six-, Nine-Year Cycles
3. Initial and Repeat Base Monitoring
Requirements
4. Increased Monitoring
5. Decreased Monitoring
6. Vulnerability Assessments
7. Relation to the Wellhead Protection
(WHP) Program
8. Phase-in by System Size
9. Sampling Points
B. Aldicarb. Aldicarb Sulfoxide. and
Aldicarb Sulfone
1. Aldicarb, Aldicarb Sulfoxide. and
Aldicarb Sulfone MCLGs
2. Aldicarb. Aldicarb Sulfoxide. and
Aldicarb Sulfone MCLs
C. Pentachlorophenol
1. Pentachlorophenol MCLC
2. Pentachlorophenol MCL
D. Barium
1. Barium MCLC
2. Barium MCL
E. 1415 Variance Option
IV. Economic Analysis
A. Regulatory Impact
B. Regulatory Flexibility Analysis
C. Paper Work Reduction Act
V. Request for Public Comments
I. Statutory Authority
The Safe Drinking Water Act
("SDWA" or "the Act"), as amended in
1986 (Pub. L 99-339, 100 Stat. 642).
requires EPA to publish "maximum
contaminant level goals" (MCLGs) for
contaminants which, in the judgment of
the Administrator, "may have an
adverse effect on the health of persons
and which [are) known or anticipated to
occur in public water systems" (section
1412(b)(3)(A)). MCLGs are to be set at a
level at which "no known or anticipated
adverse effects on the health of persons
occur and which allows an adequate
margin of safety" (see section
At the same time EPA publishes an
MCLG. which is a non-enforceable
health goal, it must also promulgate a
National Primary Drinking Water
Regulation (NPDWR) which includes
either (1) a maximum contaminant level
(MCL), or (2) a required treatment
technique (sections 1401(1), 1412(a)(3).
and 1412(b)(7)(A)). A treatment
technique may be set only if it is not
"economically or technologically
feasible" to ascertain the level of a
contaminant (sections 1401(1) and
1412(b)(7)(A)). An MCL must be set as
close to the MCLG as feasible (section
1412(b)(4)). Under the Act. "feasible"
means "feasible with the use of the best
technology, treatment techniques and
other means which the Administrator
finds are available, after examination
for efficacy under field conditions and
not solely under laboratory conditions
(taking cost into consideration)" (section
1412(b)(5)). NPDWRs also include
monitoring, analytical and quality
assurance requirements, specifically,
"criteria and procedures to assure a
supply of drinking water which
dependably complies with such
maximum contaminent levels ••*.••
(Section 1401(1)(D)). Section 1445 of
SDWA also authorizes EPA to
promulgate monitoring requirements.
II. Regulatory Background
In the 1986 Amendments to the
SDWA. Congress required that MCLGs
and NPDWRs be proposed and
promulgated simultaneously (section
1412(a)(3)). This change streamlined
development of drinking water
standards by combining two steps in the
regulation development process. Section
1412(a)(2) renamed Recommended
Maximum Contaminant Levels (RMCLs)
as Maximum Contaminant Level Goals
(MCLGs).
On July 8,1987 EPA promulgated
NPDWRs for eight volatile organic
contaminants (VOC rule). On May 22,
1989 EPA proposed monitoring
requirements for an additional 10 VOCs
and MCLGs and MCLs for 38
contaminants including aldicarb,
aldicarb sulfoxide. aldicarb sulfone,
pentachlorophenol, end barium. The
MCLGs and MCLs for these five
chemicals are reproposed today at
different levels due to information which
was received and/or analyzed by the
Agency subsequent to the May 22. 1989
proposal. Today, elsewhere in the
Federal Register, EPA is promulgating
monitoring requirements for the 38
contaminants (including aldicarb.
aldicarb sulfoxide. aldicarb sulfone,
pentachlorophenol, and barium)
contained in the May 1989 proposal,
using a standardized monitoring
framework. That final rule promulgates
MCLGs and MCLs for 33 contaminants.
III. Explanation of Today's Action
A. VOC Monitoring Requirements
1. Standardized Monitoring Framework
EPA received extensive comments on
the proposed rule of May 22,1989
(hereafter called Phase II). Many
commenters stated that the proposed
monitoring requirements are complex
and would lead to confusion and
misunderstanding among the public.
water utilities and State personnel.
Commenters also cited the lack of
coordination between various
regulations such as the 1987 VOC rule
and the proposed Phase II rule. Many
commenters suggested that EPA
simplify, coordinate, and synchronize its
regulations.
In response to these comments, EPA
developed a standard monitoring
framework to address the issues of
-------
Federal Register / Vol. 56, No. 20 / Wednesday, ianuary 30, 1991 / Proposed Rules
3601
complexity, coordination of monitoring
requirements between various
regulations and synchronization of
monitoring schedules. This framework
will serve as a guide for future source-
related monitoring requirements
adopted by the Agency.
EPA believes that trie framework will
in large measure address the comments
that recommended reducing complexity.
synchronizing monitoring schedules,
standardizing regulatory requirements,
and giving regulatory flexibility to
Siates and systems to manage
n.onitoring programs. EPA believes
these changes have the potential to
reduce costs by combining monitoring
requirements (including vulnerability
assessments) for several regulations on
the same schedule and promote greater
voluntary compliance by simplified and
standardized monitoring requirements.
Use of the framework envisions a
cooperative effort between EPA and
States. The monitoring requirements
promulgated elsewhere today for the 10
Phase II VOCs and those proposed in
this document are the minimum federal
requirements necessary to ascertain
systems' compliance with the MCLs.
The monitoring requirements outlined
in today's proposal mirror the VOC
requirements promulgated today for the
10 VOCs in the Phase II rule. If
comments and information received
during the comment period result in
changes to this proposal, EPA will
promulgate a final rule which will also
apply to monitoring requirements for the
10 VOCs promulgated elsewhere today
and the 8 VOCs included in today's
proposal. This ensures the monitoring
requirements for the 18 VOCs (the 8
Phase I VOCs and the 10 Phase II VOCs)
remain identical.
EPA's goal is to efficiently utilize
State and PWS resources and to be
consistent with Phase II monitoring
requirements. EPA believes that today's
proposal furthers that goal.
2. Three-, Six-, Nine-Year Cycles
In order to standardize monitoring
cycles in this proposed regulation (and
in future regulations), EPA established
nine-year compliance cycles. Each nine-
year compliance cycle consists of three
three-year compliance periods. All
compliance cycles and periods run on a
calendar year basis (i.e., January 1 to
December 31). The first nine-year
compliance cycle begins January 1,1993
and ends December 31, 2001; the second
cycle begins January 1. 2002 and ends
December 31. 2010; etc. Within the first
nine-year compliance cycle (1993 to
2001), the first compliance period begins
January 1.1993 and ends December 31,
1995; the second H°gins January 1,1996
and ends December 31,1998; and the
third begins January 1,1999 and ends
December 31, 2001."ln the Phase II
regulation, EPA is requiring that future
initial monitoring (defined as the first
full three-year compliance period
beginning 13 months after the
promulgation date of a rule) must begin
in the first full compliance period after
the effective dale. For today's proposed
regulation, EPA intends to promulgate
final monitoring requirements by July,
1991 to incel the 18-month minimum
before the start of the 1993 compliance
period.
3. Initial and Repeat Base Monitoring
Requirements
In the VOC rule promulgated in July,
1987, EPA required all systems to take
four consecutive quarterly samples;
however, grounchvater systems which
c.inductod a vulnerability assessment
and were judged not vulnerable could
stop m-jr.itoring after the first sample
provided no VOCs were detected in that
initial sample. Repeat frequencies for all
systems vary by system size, detection,
and vulnerability status.
EPA is pronosing several changes to
the current (i.e., 1987) VOC
requirements. EPA is also today
proposing to amend the July 1987
monitoring requirements for VOCs to
streamline the requirements and to
make all VOC requirements consistent.
In the VOC regulations promulgated
in July, 1987, distinctions in base (or
minimum) requirements were made
between ground and surface water
systems, systems which have more than
or less than 500 service connections, and
vulnerable and non-vulnerable systems.
EPA, in streamlining the requirements in
today's proposal, will require all
systems (regardless of size) to take four
quarterly samples. After the initial
round of four quarterly samples, all
systems which do not detect VOCs in
the original round of quarterly sampling
are required to monitor annually
beginning in the next calendar year after
quarterly sampling is completed. The
State may allow groundwater systems
which conducted three years of
sampling (the initial year of quarterly
sampling plus two years of annual
sampling) and did not detect VOCs to
take a single sample every three years.
For example, systems which complete
quarterly monitoring in calendar year
1993 are required to begin annual
monitoring beginning in 1994. EPA is
proposing this change for several
reasons. First, the occurrence of VOCs
in approximately 20% of systems
indicates that shortening the time frame
between when each sample is collected
for vulnerable groundwater systems
from either three or five years as
currently required to an annual sample
is appropriate. Secondly, the cost of
analysis of VOCs has decreased
somewhat since the original proposal.
Most VOC analyses now cost
approximately S150 per sample versus
the S200 per sample EPA estimated in
the 1987 VOC rule. Trihalomethanes
(THMs) may also be measured in these
samples, thereby creating efficiencies
with current and future monitoring
requirements. Consequently, the
monitoring burden on most systems is
less than previously thought. Third,
commenters on the Phase II rule
preferred annual monitoring, stating that
quarterly monitoring presented
managerial and logistical problems.
Where groundwater systems have a
demonstrated history of non-detects for
VOCs (i.e., three years) EPA believes a
reduction in annual monitoring to one
sample during each compliance period
(i.e., 3 years), if allowed by the State, is
protective of health.
EPA, in today's proposal, would
require systems to conduct an initial
round of quarterly monitoring. Because
all systems must have completed their
initial round of monitoring by January
1992, under existing requirements, the
initial monitoring requirements will only
apply to new systems or those existing
systems with a new source. Beginning in
the 1993-1995 compliance period, all
systems (except new systems or those
v.'ith nuw sources) will be required to
conduct repeat sampling for VOCs
annually. Systems which have not
conducted initial monitoring under the
existing requirements by January 1,1993
will remain subject to the existing
requirement and may be subject to
enforcement by EPA and/or the State.
4. Increased Monitoring
In the 1987 VOC rule, systems which
detect VOCs (defined as any analytical
result greater than 0.0005 mg/1) were
required to monitor quarterly for a
minimum of 12 quarters (3 years). In
today's proposal, EPA would relax that
requirement somewhat by requiring
systems which detect VOCs to only
monitor quarterly until the State allows
it to reduce the frequency to annual
sampling basad on a determination that
the system is "reliably and consistently"
below the MCL. Groundwater systems
must take a minimum of two samples
and surface water systems must take a
minimum of four samples before the
Slate may reduce the monitoring to the
base requirement (i.e., annual sampling).
States may allow systems to remain
on an annual sampling frequency even if
VOCs are detected in subsequent
-------
3602 Federal Register / Vol. 58. No. 20 / Wednesday. January 30. 1991 / Proposed Rules
samples, unless the MCL is exceeded. If
the MCL is exceeded, the system must
return to quarterly sampling in the next
calendar quarter until the State
determines that the new contamination
has decreased below the MCL and is
expected to remain reliably and
consistently less than the MCL This
determination shall again require a
minimum of four quarterly samples for
surface water systems and two
quarterly samples for groundwater
systems.
EPA is making this change because
some systems may detect VOCs at a
level slightly above the detection limit.
EPA believes that where the State can
determine that contamination is
"reliably and consistently" less than the
MCL. those systems should be able to
.return to the base monitoring
requirement (i.e.. annually). Giving
States the discretion to determine
whether systems meet this criterion will
give monitoring relief to some systems.
5. Decreased Monitoring
States may grant waivers to systems
which are not vulnerable and did not
detect VOCs while conducting base
monitoring. Vulnerability must be
determined using the criteria specified
below in the discussion of •vulnerability
assessments. Systems conducting an
assessment which considers prior
occurrence and vulnerability
assessments (including those of
surrounding systems), environmental
persistence and transport, how well the
source is protected. Wellhead Protection
Assessments, and proximity to sources
of contamination, may apply to the State
for a "susceptibility" waiver. If the
waiver is granted, systems are required
to take one sample and update the
current vulnerability assessment during
the first compliance period. The
vulnerability assessment update must be
completed by the beginning of the
second compliance period. EPA is
increasing the time frame from five, to
six years to .bring the five-year
monitoring frequency in the 1987 VOC
requirements in line with the 3/6/9-year
frequencies specified in the standard
monitoring framework.
In the VOC rule, EPA allowed States
the discretion to set subsequent
monitoring frequencies in surface water
systems which did not detect VOCs in
the initial round of four quarterly
samples and that were designated as not
vulnerable based on assessment. This
provision is unchanged by today's
proposed rule.
Table 1 provides a comparison of the
VOC monitoring requirements specified
in the July 1987 rule and those proposed
in today's proposed rule.
TABLE 1 .—COMPARISON OF CURRENT AND PROPOSED VOC MONITORING REQUIREMENTS
Source
Current requirement
Proposed requirement
Initial Monitoring
Surface
Ground _.
Source
Repeat
Monitoring
frequency:
Surface
Ground _.
Surface
Ground
Surface
Ground
Frequency:
Size
N/A _. . _
N/A
>500 connections
<500 connections......
>SOO connections -.
les
Occurrence
no detect
no detect
no detect
no detect
no detect _..
no detect
detect
detect
4 quarterly samples.
4 quarterly samples.
Current requirements
State discretion
1 sample/5 year
4 quarterly samp
4 quarterly samp
1 sample/3 year
1 sample/ 5 year
quarterly '
quarterly *
3 _
des/3 years
les/5 years
£ .
Proposed requirements
State discretion
1 sample/6 years
1 sample annually *
1 sample annually *
1 sample annually *
1 sample annually -
quarterly «
quarterly4
' May be reduced to 1 sample provided sample does not detect.
* State may reduce to 1 sample during each 3 year compliance period after 3 years
9 State may reduce to annual after 12 quarters consistently < MCL
* State may reduce to annual after 4 quarters "reliably arid consistentty" < MCL for surface systems Ground water systems may be reduced to annual after 2
quarters "reliably and consistently" < MCL.
6. Vulnerability Assessments
In today's proposal EPA is making
several changes to the VOC
vulnerability assessment criteria. In the
1987 VOC rule."EPA listed five criteria
systems must consider in conducting
vulnerability assessments: previous
monitoring results: number of people
served: proximity to a large system:
proximity to commercial or industrial
use. storage, or disposal of VOCs; and
protection of the water source.
EPA is proposing several changes to
the vulnerability assessment criteria and
the process of conducting vulnerability
assessments in order to simplify the
procedure. First, a two-step procedure is
available to all systems. Step #1: A
system determines whether the
contaminant was used, manufactured.
stored, or disposed of in the area. For
some contaminants, an assessment of
their use in the treatment or distribution
of water may also be required. "Area" is
defined as the watershed area for a
surface water system or the recharge
zone for a groundwater system and
includes effects in the distribution
system. If the State agrees with the
system that the contaminant was not
used, manufactured, stored, transported.
etc., the State may grant the system a
"use" waiver. If the State cannot make
this determination, a system may not
receive a "use" waiver, but may receive
a "susceptibility" waiver discussed
below. Systems receiving a "use"
waiver are not required to continue on
the Step #2 to determine susceptibility.
EPA anticipates that obtaining a "use"
waiver will apply mostly to pesticides/
PCBs where use can be determined
more easily than for VOCs. Obtaining a
"use" waiver for the VOCs will be
limited, because VOCs are ubiquitous in
the United States. If a "use" waiver
cannot be given, a system may conduct
an assessment to determine
susceptibility.
Susceptibility considers prior
occurrence and/or vulnerability
assessment results, environmental
persistence and transport of the
chemical, how well the source is
-------
Federal Register / Vo!, 56. No. 20 / Wednesday, January 30, 1991 / Proposed Rules
3603
protectfd, and Wellhead Protection
Program reports. Systems with no
known "susceptibility" to contamination
based upon an assessment of the above
criteria may be granted a waiver by the
State. If "susceptibility" cannot be
determined, a system is not eligible for a
waiver. Systems must receive a waiver
by the beginning of the calendar quarter
it is scheduled to begin monitoring. For
example, if a system is scheduled to
begin monitoring in the calendar quarter
beginning January 1,1993, it must
receive a waiver by December 31,1992
for reduced monitoriing to apply.
EPA will permit "area wide" or
geographical vulnerability assessment
determinations. Though EPA at this time
is skeptical that "area wide"
determinations can be conducted with
sufficient specificity to predict
contamination over a large area, EPA
v. ill allow this option when States
submit their rules and procedures for
primacy review of these requirements.
EPA's goal is to combine vulnerability
assessment activities in other drinking
water programs with today's
requirements to create efficiencies. EPA
also desires to use insofar as possible
the results of other regulatory program
requirements, such as Wellhead
Protection assessments, to determine a
system's vulnerability to VOC and
pesticide/PCB contamination. Systems
and States may coordinate the
assessments with sanitary surveys
required under the Total Coliform rule
40 CFR 141.21, watershed assessments,
end other water quality inspections so
that all regulatory, operational, and
managerial objectives are met at the
same time.
EPA intends to issue a guidance in
1991 that will give flexibility to States in
reviewing vulnerability assessments and
to systems in conducting them. Also,
this guidance will allow systems to use,
in part the requirements under the
Wellhead Protection program to satisfy
similar requirements of both programs
with one assessment. Additionally, this
combined assessment approach may be
used in part, to meet similar
requirements under the evolving
Underground Injection Control-Shallow
Injection Well Program.
7. Relation to the Wellhead Protection
(WHP) Program
The Agency planned to integrate
particular elements of the Public Water
Supply, Wellhead Protection and
Underground Injection Control (UIC)
programs related to contaminant source
assessments around public water supply
wells prior to receiving comments to
!hat effect. Comments received on the
proposed Phase II Rule reinforce and
support this interest. Specifically, the
Agency plans to prepare a guidance
document on groundwater contaminant
source assessment merging vulnerability
assessments for the protection of water
supplies from pesticides and VOCs with
similar requirements for UIC shallow
injection wells and the wellhead
delineation and contaminant source
iissessment requirements of the WHP
program. This integration is expected to
assist State and local drinking water
program managers responsible for
groundwater supplies to more efficiently
and effectively administer the portion of
their programs addressing source
protection and will be the basis for
determining monitoring frequency. The
guidance will give States flexibility in
reviewing vulnerability contaminant
source assessments.
8. Phase-in by System Size
. Initial monitoring for new systems is
defined as the first full three-year
compliance period which occurs after
the regulation is effective. As discussed
earlier, new systems must monitor at the
base monitoring frequency unless a
waiver is obtained. The initial
monitoring period for systems
established after January 1,1993 under
today's regulation begins January 1,1993
and ends December 31.1995. Initial
monitoring for systems established prior
to December 31,1992 remains subject to
the initial monitoring requirements in
§ 14l.41(g). After the initial monitoring
requirement is met, systems must
monitor at repeat frequencies as
proposed today.
Current requirements mandate that
systems are required to monitor for
VOCs through a phase-in procedure.
Community systems serving more than
10,000 persons are required to complete
initial monitoring by December 31,1988,
systems serving 3,300 to 10,000 persons
are required to complete initial
monitoring by December 31,1989, and
community systems serving fewer than
3,300 persons are required to complete
initial monitoring by December 31.1991.
Non-transient non-community water
systems are required to complete initial
monitoring by December 31,1991.
In today's proposal, EPA allows
States the flexibility to designate which
systems must monitor each year based
upon criteria such as system size,
vulnerability, geographic location, and
laboratory access. EPA will require the
State to schedule approximately one-
third of the systems each year as a
primacy condition. EPA believes that
allowing States the discretion to
schedule monitoring for each system
during the compliance monitoring period
will allow States to manage their
drinking water programs more
efficiently.
Once a system is scheduled for the
first, second, or third year of a
compliance period, the repeat schedule
is set for future compliance periods. For
example, if a system is scheduled by the
State to complete the initial base
requirement by the end of the first year,
all subsequent repeat base monitoring
for that system must be completed by
the end of the first year in the
appropriate three-year compliance
period. This is necessary to prevent
systems from monitoring in the first year
of the first compliance period and the
third year of the repeat base period.
9. Sampling Points
EPA has received information
suggesting that petroleum and
hazardous material spills and leaks
have contributed to drinking water
contamination in systems using plastic
pipe. EPA is concerned about this issue
because this contamination typically
occurs after sampling and consequently
would not be detected.
Volatile organic chemicals (VOCs)
can contaminate and enter a drinking
water distribution system from three
distinct pathways: (1) through
contamination at the source; (2) through
a cross connection: and (3) through
permeation of plastic pipe. EPA's
National Primary Drinking Water
Regulations (NPDWR) protect drinking
water systems from contamination
through pathways (1) and (2). However,
no Federal regulations protect PWSs
from contamination by VOC permeation
of plastic pipe. The NPDWR only require
that VOCs be tested after treatment—
not at the tap. Therefore, contamination
from a leaking underground storage tank
within the distribution system typically
would not be detected. Cross connection
control devices are ineffective in
controlling contamination along the
length of a plastic pipe.
The use of plastic pipes such as
polyethylene (PE), polybutylene (PD),
polyvinyl chloride (PVC). chlorinated
polyvinyl chloride (CPVC) and
acrylonitrile-butadiene-styrene (ABS)
has increased dramatically since 1960.
During the last decade, however, it has
been found that some plastic piping
materials and gasket materials are
susceptible to attack by some organic
chemicals and become permeable to
them. The literature on VOC permeation
of plastic pipe clearly indicates that this
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3604 Federal Register / Vol. 56. No. 20 / Wednesday. January 30. 1991 / Proposed Rules
is a significant source contamination in
the distribution system of some PWSs.
In order to address this issue EPA is
modifying the sampling point
designations of § 141.24(f) (1) and (2) to
allow the State to designate additional
sampling points within the distribution
system or at the consumer's tap to more
accurately determine consumer
exposure. EPA requests comment on this
issue and additional information on the
permeation of plastic pipe by VOCs.
B. Aldicarb. Aldicarb Sulfoxide. and
Aldicarb Sulfone
1. Aldicarb, Aldicarb Sulfoxide, and
Aldicarb Sulfone MCLGs
In the May 22,1989 proposal (54 FR
22062) EPA proposed separate MCLGs
for aldicarb. aldicarb sulfoxide, and
aldicarb sulfone at 0.01,0.01, and 0.04
mg/1, respectively. EPA also requested
comments on whether a single MCLG
should be set for total aldicarb (parent,
suifoxide, and sulfone) based upon the
most toxic component of the mixture
(i.e.. sulfoxide with the MCLG of 0.01
mg/1) as was originally proposed in the
November 13,1985 Federal Register.
Alternatively, a single MCLG might be
based upon fractionation of the total
mixture depending upon the percentage
of each individual component of the
mixture, ensuring that each individual
component did not exceed its individual
MCLG; these calculations were
demonstrated as follows:
Aldicarb (Aldicarb measured)
0.01 mg/1
sulfoxide sulfone
+
0.01 tng/1 0.04 mg/l
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Federal Register / Vol. 56. No. 20 / Wednesday, January 30. 1991 / Proposed Rules
3605
of C.04 r.g/1). The calculations are as
follows:
Aldicarb and aldicarb sulfoxide:
0.0002 mg/kg/day X TO kg body weight x 20% RSC
2 liters
0.0014 mg/1 rounded to O.OOi rr.g/1
Aldicarb sulfone:
0.0003 mg/kg/day x TO kg body weight x 20% RSC
2 liters
0.0021 mg/1 rounded to 0.002 mg/i
The reproposed MCLGs in this
proposed rule are one order of
magnitude lower than the values
proposed in the May 22,1989, Federal
Register. Thus, the reproposed MCLGs
for aldicarb and its metabolites are as
protective of the child as the value
calculated by the National Academy of
Science in 198C. Because the information
on which the Agency relied in
rcproposing these new MCLGs did not
result from public comments on the May
1989 proposal nor has it been subject to
public review, we are reproposing the
MCLGs for comment.
In the May 22.1989, proposal, the
Agency used the six-month rat studies
by Weil and Carpenter (1968} for the
RfD. That RfD for aldicarb was
supported by the NAS (1986) calculation
for a potential NOAEL for aldicarb in
humans at 0.01 mg/kg/day. However, as •
noted in the public comments in the May
22,1989, proposal, the MCLG based on
these data provided a margin of safety
less than 10 for 13 percent of the infants.
Therefore, with the use of the one-year
dog study (Hazleton, 1987) not available
for consideration in setting MCLGs at
the time of the May 1989 proposal, and
the data from the human volunteer study
(Haines, 1971) described by the NAS
(1906), a lower RfD, 0.0002 mg/kg/day.
was obtained (EPA, 1990a) that provided
the basis for the calculation of a 10-fold
lower proposed MCLG for aldicarb. This
MCLG provides a more adequate margin
of safety for both adults and children.
This study has not previously been
subject to public comment.
The 1988 one-year aldicarb dog
feeding study (Hazleton. 1988 #400-706)
with aldicarb that is used in the
calculation of the new RfD is described
below. Groups of beagle dogs (5/sex/
dose) were administered aldicarb
technical in the diet daily for 52 weeks
at levels of 0.1. 2, 5. or 10 ppm (Male: 0,
0.028. 0.054. 0.132. or 0.231 mg/kg/day:
female: 0, 027, 0.055, 0.131, and 0.251 mg/
kg/day). Animals received food and
water ad libitum. At the end of the study
period the actual lowest dose consumed
by the male group was 0.02 mg/kg/day.
The main effect noted at this level was
an average of approximately 25 percent
inhibition of plasrnff cholinesterase in
both sexes at the end of the study period
(52 weeks).
From this study, it was concluded that
aldicarb, when administered in the diet
of male and female beagle dogs daily for
52 weeks at all the doses tested, did not
produce any mortality or changes in
body weight gain, appearance or
behavior, or food or water consumption.
There was an increase in the combined
incidences of soft stools, mucoid stools,
and/or diarrhea in male and female
dogs given 2, 5, or 10 ppm. Dose-related
inhibition of plasma cholinesterase
activity was observed in male dogs
given 2, 5, or 10 ppm aldicarb technical
at all time intervals. Plasma ChE
inhibition was also noted in the 1-ppm
group (0.02 mg/kg/day) at 52 weeks in
both males and females; however, this
level of inhibition was found to be
within the historical control range.
Plasma cholinesterase inhibition
occurred in female dogs given 5 or 10
ppm aldicarb technical at all intervals
and in the 2-ppm group at weeks 5 and
13. Red blood cell (RBC) cholinesterase
inhibition was noted in a dose-related
fashion in both males and females at the
5- and 10-ppm groups in this study. At 2
ppm. only males exhibited some effects
(28.6 percent inhibition) at week 13. RBC
ChE inhibition was noted in female dogs
given 10 ppm at all intervals except
week 52. The average brain
cholinesterase activity, measured at the
end of the study, was inhibited only in
male dogs in a dose-related fashion at 2.
5, and 10 ppm aldicarb (15. 20 and 30
percent average inhibition, respectively).
No compound-related changes in
hematology. parameters regarding
clinical chemistry, urinalysis. organ
weight, gross pathology, ophthalmology,
or histopathology were noted in any of
the treatment groups.
Therefore, the RfD for aldicarb was
calculated using 0.02 mg/kg/day dose
level in the dog study and a 100-fold
uncertainty factor. These data were
supported with a parallel calculation
using the human study (Haines, 1971)
with the actual lowest dose tested, 0.025
mg/kg/day (a range of approximately 30
to 57 percent whole blood ChE
inhibition) and a 100-fold uncertainty
factor. The NAS (1986) extrapolated
estimate of 20 percent whole blood ChE
inhibition from the Haines study is 0.005
mg/kg/day. This estimate provides a 30-
fold margin of safety for human adult
males (Haines, 1971) when compared to
the new RfD and a 10-fold margin of
safety for the human population in
general (Goldman et al.. 1990).
For aldicarb sulfone the new one->ear
dog feeding study by Hazleton (1987)
was used for the calculation of the RfD.
In this study, groups of beagle dogs (6/
sex/dose) were administered aldicarb
sulfone in the diet for one year at levels
of 0.5.25. or 100 ppm (0,0.11.0.58, and
2.21 mg/kg/day). Since aldicarb sulfone
was found to be unstable in the diet at
room temperature, fresh diets were
prepared weekly and frozen
immediately following mixing.
Statistically significant inhibition of
plasma cholinesterase was observed in
males at all doses tested (20-C9 percent
inhibition of control value) and at the
mid- and high-dose levels in females
(40-72 percent inhibition of control
value) at all intervals. Red blood cell
cholinesterase also was significantly
inhibited in the mid-dose groups for both
males (17 percent) and females 20
percent) and in the high-dose males (3b
percent) and females (29 percent) when
compared to the control value. Brain
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3606 Federal Register / Vol. 56. No. 20 / Wednesday, January 30, 1991 / Proposed Rules
cholinesterase activity at study
termination showed statistically
significant inhibition in high-dose males
(24% reduction compared to control
value) and mid- and high-dose females
(19-23 percent reduction compared to
control). Therefore, the lowest dose
tested. 0.11 mg/kg/day (5 ppm),
reflecting an average of 25 percent
plasma ChE inhibition in one sex. males.
was used in the calculation of the RfD
by the application of a 300-fold
uncertainty factor. Although the sulfone
is known to be less toxic than the parent
compound and the sulfoxide, the Agency
justifies the use of a 300-fold uncertainty
factor instead of the 100-fold that is used
with the parallel 1-year dog study with
aldicarb based on the fact that the data
for aldicarb were supported further by
-human data, if human data with
aldicarb sulfone become available to the
Agency, the extra 3-fold used in the RfD
calculation for aldicarb sulfone may not
be necessary (in this case, the RfD
would be amended then to 0.001 mg/kg/
day and the .MCLG to 0.007 mg/I). The
extra 3-fold uncertainty factor might
also be unnecessary if the human data
for the aldicarb parent is considered to
be applicable to aldicarb sulfone and/or
if the 5 ppm low dose is considered to be
a NOAEL for aldicarb sulfone. Public
comment on this issue is requested.
including the alternate MCLG of 0.007
mg/1 for aldicarb sulfone.
The MCLGs of 0.01.0.01, and 0.04 mg/1
for aldicarb that were proposed in the
May 22,1989. Federal Register are now
proposed at 0.001,0.001, and 0.002 mg/1,
respectively, based on the Agency's new
verified RfDs (EPA, July 1990 a and b).
as discussed above. In addition, an
MCLG of 0.001 mg/1 for the mixture of
two or more of these compounds is
proposed.
2. Aldicarb. Aldicarb Sulfoxide. end
Aldicarb Sulfone MCLs
The SDWA directs EPA to set the
MCL "as close to" the MCLG "as is
feasible." The term "feasible" means
"feasible with the use of the best
technology, treatment techniques, and
other means, which the Administrator
finds, after examination for efficacy
under field conditions and not solely
under laboratory conditions, are
available (taking costs into
consideration)." (SDWA Section
1412(b)(5).J Each National Primary
Drinking Water Regulation that
establishes an MCL lists the technology,
treatment techniques, and other means
which the Administrator finds to be
feasible for meeting the MCL (SDWA
Section 1412(b)(6)). EPA elsewhere in
today's Federal Register has
promulgated best available technology,
analytical methods and monitoring
requirements for aldicarb. aldicarb
sulfoxide, aldicarb sulfone, and
pentachlorophenol. GAC is the only
available treatment technology that
removes these organic contaminants
and can be implemented at virtually any
contaminant level. Further, the
analytical methods and monitoring
requirements are not expected to be
affected by whatever MCLGs and MCLs
are promulgated for these four
chemicals, as well as barium. Therefore.
EPA has not replicated those
discussions in this proposal.
The MCLs for alicarb. aldicarb
sulfoxide, and aldicarb sulfone are
reproposed in this proposed rule, based
upon an analysis of several factors.
including:
(1) The effectiveness of BAT in
reducing contaminant levels from
influent concentrations to the MCLG.
GAC was proposed as BAT for these
chemicals. This reproposal would not
affect that designation. GAC is effective
in removing aldicarb. aldicarb sulfoxide
and aldicarb sulfone to levels at or
below the MCLS of 0.003 mg/1.
(2) The feasibility (including costs) of
applying BAT. EPA considered the
availability of the technology and the
costs of installation and operation for
large systems (serving more than
1.000,000 people). EPA estimates the cost
to remove aldicarb, aldicarb sulfoxide,
or aldicarb sulfone. using GAC, to be
S10-S14 per household.
(3) The performance of available
analytical methods as reflected in the
practical quantitation level (PQL) for
each contaminant. In order to ensure the
precision and accuracy of analytical
measurement of conta'minants at the
MCL, the MCL is set at a level no tower
than the PQL Data showed that the
PQLs for aldicarb and aldicarb sulfoxide
could be lowered from levels of 0.005
and 0.008 mg/1 to 0.003 mg/1. The PQL
for aldicarb sulfone was proposed at a
level of 0.003 and the Water Supply
Studies confirm that this level is
achievable. In order to establish a PQL
of 0.003 mg/1. EPA has broadened the
acceptance limits to ± 55 percent. EPA
believes that somewhat less precise
analytical data are acceptable in this
case, where the-respective MCLGs for
aldicarb, aldicarb sulfoxide, and
aldicarb sulfone are 0.001.0.001. and
0.002 mg/1, to narrow the gap between
the MCLs and the MCLGs. EPA believes
that PQLs of 0.003 mg/1 represent the
lowest level feasible using current
analytical methodology. The factors
EPA used in its analysis to establish
MCLs of 0.003 mg/1 for aldicarb,
aldicarb sulfoxide. and aldicarb sulfone
are summarized in Table 2.
TABLE 2.—MCL ANALYSIS FOR ALDICARB, ALDICARB SULFOXIDE, ALDICARB SULFONE. AND PENTACHLOROPHENOL
SOC contaminant
Aldicarb..
Aldicarb suKoxide. . - . - .. -.
Aldicarb sulfone . -. -.
Pentacnloropfienol - -
MCLG (mg/1)
0.001
.001
.002
MCL (mg/1)
0.003
.003
.003
.001
FOi. (mg/1)
0.003
.003
.003
.001
Annual household
costs using BAT*
GAC | PTA
$10.00
14.00
14.00
10.00
s—
10 'Risk
(mg/1)
NA
NA
NA
0.03
• For targe surface systems serving > 1.000.000 people.
Although the MCLs for aldicarb,
aldicarb sulfoxide, and aldicarb sulfone
are proposed at a level above the
MCLG, EPA believes the health risks of
exceeding the MCLG up to the MCL are
minimal This rationale is based on the
fact that from the NAS (1986) analysis of
the human study with bolus exposure to
aldicarb (1971). 0.002 mg/1 was
calculated for the child exposure.
However, it is unlikely that a child will
consume a whole liter at one time.
Therefore, the MCL value of 0.003 mg/1
is protective to the child in
consideration that it would provide the
0.003 mg aldicarb in fractional
exposures of 0.0015 mg or less, assuming
that the child consumes the one liter of
water in two or more equal drinks.
Considering that the cholinesterase
inhibition effects of aldicarb are thought
to be reversible within 4 to 6 hours at
higher levels of exposure (i.e., 0.025 mg/
kg. Haines. 1971). the MCL for aldicarb
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Federal Register / Vol. 56, No. 20 / Wednesday. January 30, 1991 / Proposed Rules 3807
and its metabolites. 0.003 mg/1. should
be protective for a child.
Consequently, for the above reasons.
the MCLs for aldicarb, aldicarb
sulfoxide, and aldicarb sulfone are each
proposed at 0.003 mg/1.
C. Pentachlorophenol
1. Pentachlorophenol MCLG
EPA proposed an MCLG of 0.2 mg/1
for pentachlorophenol in the May 22,
1989 proposal. The MCLG was derived
from a DWEL of 1 mg/1 applying a 20
percent contribution from drinking
water. At the time of proposal,
pentachlorophenol's carcinogenic
classification was in Group D. However.
recent carcinogenicity bioassays were
positive for carcinogenic effects in mice
given either purified commercial or
technical grades of pentachlorophenol in
the diet Due to these test results,
comment was also requested regarding
the possibility of an MCLG of zero for
pentachlorophenol, based on a revised
classification of B2 indicating sufficient
evidence of carcinogenicity in animals.
Eight commenters responded to the
Federal Register proposed rule of May
1989. Four commenters believed the
recent carcinogenicity data support
reclassification of pentachlorophenol
into Group C (from Group D). Their
reasons include (1) the studies are
actually only one study with one species
giving a positive response; (2) the
relevance of mouse liver tumors and
adrenal pheochromocytomas is
questionable, and two of the three
treatment-related tumor types observed
are of questionable value for predicting
cancer risk in humans; (3) impurities in
the pentachlorophenol in both studies
could be responsible for the observed
carcinogenicity; (4) the tumors possibly
resulted from secondary taxic effects
instead of from a direct effect of
pentachlorophenol; and, (5) evidence for
the inability of pentachlorophenol to
cause mutations detracts from setting an
MCLG of zero and the coincident non-
threshold position for carcinogens. All of
these four commenters prefer retaining
the proposed MCLG of 0.2 mg/1. Two
commenters supported the
reclassification of pentachlorophenol
into Group B2 and the proposed MCLG
of zero, concluding that the recent
carcinogenicity data meet the EPA
guidelines requirements for sufficient
evidence in animals. Three commenters
wanted the reclassification issue
postponed because of insufficient time
for the public to evaluate the
carcinogenicity bioassay. These
commenters postulated that the
carcinogenic effects may have been
induced by impurities in the test
compound or by the dosing vehicle,
instead of by pentachlorophenol itself.
EPA Response. EPA concludes upon
further evaluation of the carcinogenicity
studies that these studies support
reclassification of pentachlorophenol
into Group B2 (sufficient evidence in
animals). EPA considers that the
appearance of multiple tumor types
(hemangiosarcomas.
pheochromocytomas, and liver tumors)
at different dose levels in both sexes of
mice satisfies the criteria for sufficient
evidence for carcinogenicity. EPA
concludes there is inadequate evidence
to exclude pentachlorophenol as the
agent including the tumors observed.
because impurities in the
pentachlorophenol test materials have
not been shown to induce
hemangiosarcomas or
pheochromocytomas, and the impurities
in the test materials are considered to
be of inadequate quantity to account for
the treatment-related increases in liver
tumors. EPA also feels the evidence is
inadequate to discount the results due to
concerns regarding non-genotoxic and
secondary toxic mechanisms of
carcinogenic action. The mechanistic
arguments need further development to
successfully refute the evidence for
pentachlorophenol as a probable human
carcinogen. EPA also cannot discredit
the mouse liver tumors and adrenal
pheochromocytomas as signs of
pentachlorophenol carcinogenicity
because, since positive results in animal
studies trigger concern about
carcinogenic hazard in humans, it is
difficult to ignore such data.
EPA's conclusion on a B2
classification has been reviewed and
supported by the Science Advisory
Board in February, 1990. EPA's
conclusion is also consistent with the
unanimous conclusion of the NTP Peer
Review Panel that for technical grade
pentachlorophenol there is clear
evidence of carcinogenic activity in
male mice and some evidence in female
mice, and that for purified commerical
grade pentachlorophenol there is clear
evidence of carcinogenic activity in both
male and female mice. For these
reasons, EPA places pentachlorophenol
in Category I and proposes an MCLG of
zero.
2. Pentachlorophenol MCL
In the May 22.1989 proposed rule,
EPA proposed a MCL of 0.2 mg/1 based
upon EPA's placement of.this chemical
in Category in (inadequate evidence of
carcinogenicity via ingestion). In that
proposed rule EPA also stated that there
is considerable evidence that could
result in reclassification to Group B2
and subsequent placement in Category I.
The proposed rule further stated that
based upon a B2 classification the
MCLG would be zero and the MDL
would be set at the PQL of 0.0001 mg/1.
No comments were receivpd on what
the appropriate MCL should be for
pentachlorophenol. EPA is reproposing
the MCL for pentachlorophenol because
it believes the data more appropriately
support an MCL of O.OC1 mg/1 due to
additional information which was
analyzed by the Agency as discussed
below.
The proposed MCL for
pentachlorophenol is established based
upon an analysis of several factors as
discussed below and summarized in
Table 2:
(1) The effectiveness of BAT in
reducing the contaminant levels from
influent concentrations to the MCL. For
pentachlorophenol the Agency has
determined that granular activated
carbon is BAT. This technology is
effective in reducing influent
concentrations to the proposed MCL of
0.001 mg/1 or to the alternate MCL of
0.0001 mg/1.
(2) The feasibility (including costs) of
applying BAT. EPA considered the
availability of GAC and the costs of
installation and operation for a large
system. EPA estimates that large system
household costs to treat at or below the
MCL are approximately $10 per year.
Consequently. EPA believes that GAC
as BAT is feasible.
(3) The performance of available
analytical methods as reflected in the
PQL In order to ensure the accuracy of f
analytical measurement of contaminants
at the MCL. the MCL is set at a level no
lower than the PQL In the May
proposed rule EPA stated that it
estimated the PQL to be 0.0001 mg/1
which was 10 times the minimum
detection limit of 0.00001 mg/1. A final
PQL would be established along with
acceptance limits based upon an
analysis of ongoing water supply -
studies. Upon analyzing Water Supply
Studies 20-25, EPA has concluded that
the PQL should be established a! 0.001
mg/1 with an acceptance limit of ±50
percent EPA analysis of the Water
Supply data indicates that around the
0.001 mg/1 level laboratory performance
falls sharply. During its consideration of
where to set the PQL EPA also
considered establishing the PQL at
0.0001 mg/1 with an acceptance limit of
±55 percent However..the Agency has
• concluded that the need for better
quality analytical data overrides the
need to establish a lower PQL in this
case, particularly when the. risks are
below 10'*. as discussed below. EPA
desires comment on the issue of whether
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3608 Fedora; Register / Vol. 55. No. 20 / Wednesday, January 30, 1991 / Proposed Rules
it is desirable to establish a lower PQL
v/ith less stringent acceptance limits
when risks are low. EPA particularly
desires comments on whether the PQL
should be set at 0.001 mg/1 as proposed
or at an alternate level of 0.0001 mg/1.
(4) After taking into account the above
factors. F.PA then considered the risks at
the MCL level for Category i
contaminants to determine whether they
would adequately protect public health.
EPA considers a target risk range of 10"4
to 10~s to be safe and protective of
public health. After EPA changed the
cancer classification from D to B2 the
Agency subsequently developed a
cancer unit risk estimate of 4.76E-08
cases/person/(/ig/l)/yr. In evaluating
where to set the MCL after evaluating
the Agency's cancer risk estimate as
applied to drinking water, the EPA
concluded that the risk of cancer from
pentachlorophenol was low—less than a
10"6 risk at an MCL of 0.0001 mg/1.
Consequently, EPA concludes that
proposing an MCL level of 0.001 mg/1 is
more consistent with its policy to
establish MCLs in the 10"4 to 10"6risk
range. EPA requests comment on this
issue if the MCL should be established
at a level below the 10"'risk level.
D. Barium
1. Barium MCLG
In the 1989 proposal (54 FR 22062),
EPA proposed an MCLG of 5 mg/1 for
barium and specifically requested
comment on the approach used to derive
the 5 mg/1 value.
The proposed 5 mg/1 MCLG was
based on several human and animal
studies. The Wones et al. human clinical
study failed to detect adverse effects at
10 mg/1. EPA applied an uncertainty
factor of 2 to derive an MCLG of 5 mg/1,
rather than a factor of 10, which would
normally be applied with a human study
with a NOAEL because the study is
corroborated by the results of other
studies (i.e., the Brenniman et al., 1981
study). EPA did not factor the RSC into
the calculation of the MCLG since the
basis is a human study that considered
contributions from food and air. The
proposed MCLG was supported by the
results of Brenniman et al., which failed
to find adverse effects at a slightly
higher level of 7.3 mg/1 and is consistent
with the 4.7 mg/1 value recommended by
the National Academy of Science.
Subsequent to the May 1989 proposal,
the Agency reviewed the data and
adopted an RfD for barm. .ThatRfD
concludes that the uncertainty in the
data base was such as to warrant an
uncertainty factor of three—greater than
the proposed value of two. EPA's usual
practice is to use an uncertainty factor
of 10, 3 or! when the RfD is based on
human data. EPA in this case believed
!hat the uncertainty in the data base
was such as to warrant use of three
rather than two, as proposed, to support
its conclusion of greater uncertainty in
t!;e data base. Based on the revised RfD,
the MCLG is reproposed at 2 mg/1.
Public Comment. The majority of the
comments agreed with the approach that
EFA used to arrive at a 5 mg/1 value and
urged that EPA adopt a 5 mg/1 MCLG for
barium. The remaining comments were
unclear as to their intent (i.e., whether a
lower or higher MCLG was appropriate).
These comments noted that, as no
effects were observed in Wones et al. at
10 mg/1, the highest level tested, EPA
had not used a NOAEL Though
unstated, these commenters presumably
believe that, had the Wones et al. study
used higher levels of barium, no effects
would have been observed at levels
greater than 10 mg/1 and thus an MCLG
greater than 5 mg/1 would be
appropriate.
EPA Response. EPA disagrees with
comments that noted that no effects
were observed at the highest level of
barium tested by Wones et al., 10 rng/1,
and thus, presumably, argued that a
higher MCLG may be appropriate. EPA
is obliged to use the available data and,
in EPA's opinion, there are no data that
adequately support the conclusion that
an MCLG higher than 5 mg/1 will protect
the public "with an adequate margin of
safety." It is clear that the majority of
commenters agreed with the basic
approach EPA used to derive the
proposed 5mg/l. EPA is not changing
that approach; however, EPA believes
that it is appropriate to change the
uncertainty factor used in that approach.
Normally when using human data EPA
uses an uncertainty factor of 10. Both
EPA and the majority of commenters
agreed that an uncertainty factor of 10
was too conservative in this case.
However, EPA believes the uncertainty
factor of two may not be cautious
enough to adequately protect the most
sensitive populations with an adequate
margin of safety. To allow for this EPA
determined it was appropriate to use a
slightly greater uncertainty factor of
three. Consequently, for the reason
stated above, barium is placed in
Category III and en MCLG of 2 mg/1 is
proposed.
2. Barium MCL
The current barium MCL of 1 mg/1
was promulgated in 1975 (40 FR 59570).
EPA notes the proposed MCL would
raise the level from 1 mg/1 to 2 mg/1.
EPA believes the current standard is
feasible and consequently believes the
revised standard of 2 mg/1 is likewise
feasible. Consequently, the MCL for
barium is proposed at 2 mg/1.
£. 1415 Variance Option
EPA at the time that it proposes and
promulgates regulations must establish
a Best Available Technology (BAT) for
both the maximum contaminant level
(MCL) [under section 1412] and the
variance (under section 1415). Section
1415(a)(l)(A) states that:
The Administrator's finding of best
available technology, treatment techniques or
other means for purposes of this subsection
may vary depending on the number of
persons served by the system or for oiher
physical conditions related to engineering
feasibility and costs of compliance with
maximum contaminant levels as considered
appropriate by the Administrator.
EPA makes its BAT determinalion on
a national basis. In making its decision,
the Agancy examines factors such as
whether systems of a particular size can
successfully operate the treatment and
whether some technologies cannot be
successfully down sized from water
supplies serving many people to those
serving a few people.
For water supplies serving less than
500 service connections, the SDWA
permits the State to grant an initial
exemption from compliance with the
MCL of three years with one or more
additional two-year extensions if the
system is taking all practicable steps'to
meet the requirements. Section
1416(b)(2)(C). These water supplies may
need financial assistance because the
costs involved in meeting the regulations
exceed a reasonable level. Systems
serving more than 500 service
connections are eligible for a one-time
three-year exemption.
EPA believes there may be some
water supplies that serve more than
1.500 people (500 service connections)
but less than 3,300 people (1,000 service
connections) that face high compliance
costs. Data analyzed by EPA indicate
that systems serving more than 3,300
people would not encounter
unaffordable costs. Consequently. EPA
is limiting the variance option discussed
today only to those systems not eligible
for additional exemptions beyond the
initial three-year exemption (i.e.,
eystems serving more than 1,500 people
but less than 3,300 people). EPA today is
proposing to develop a mechanism to
give these systems future regulatory
relief.
Section 1415(a)(l)(A) permits the
Administrator to make a decision that
BAT is not available for specific
systems due to costs exceeding certain
defined limits. If the Administrator
decided that BAT is not available for a
particular contaminant, a water system
may be eligible for a variance. EPA has
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3609
not yet developed criteria for
determining whether BAT is affordable
for systems sizes that are the subject of
this proposed rule, but EPA intends to
do so in the future. At that time. States
could grant variances in accordance
with EPA's criteria; until the criteria are
published, no variances based on
affordability are available. EPA is today
soliciting public comment on the concept
described here, particularly, whether
variances should be limited to systems
serving less than 3,300 people, or should
be available to other systems (or all
systems); what criteria should EPA
consider in determining whether BAT is
affordable; is a percentage of median
household income an appropriate
measure of affordability (see, for
example, the final rule promulgated
today that discusses two percent of
median household income as an
indicator of affordability) for
exemptions under section 1416; should
variances based on affordability be
extended to all applicable SOW A
regulations.
IV. Economic Analysis
Executive Order 12291 requires EPA
and other regulatory agencies to perform
a regulatory impact analysis (RIA) for
all "major" regulations, which are
defined as those regulations which
impose an annual cost to the economy
of S100 million or more, or meet other
criteria. The Agency has determined
that the proposed rule is a minor rule for
purposes of the Executive Order. This
regulation has been reviewed by the
Office of Management and Budget as
required by the Executive Order and
any comments they make will be
available in .the public docket.
In accordance with the Executive
Order, the Agency has conducted an •
assessment of the benefits and costs of
regulatory alternatives as part of the
Phase II rule which is promulgated
elsewhere in today's Federal Register.
This assessment in the Phase II rule
determined the impacts of this proposed
regulation as part of the Phase II rule
and consequently these impacts are not
separately reconsidered in this proposed
rule.
A. Regulatory Impact
EPA's analysis conducted under the
proposed rule for 38 contaminants (54
FR 22062, May 22.1989) indicates that
approximately 378 systems would
violate the proposed aldicarb MCL of
0.01 mg/1. An additional 825 systems
would violate the MCL for »
pentachlorophenol.
The aldicarb estimate was based on
one State survey which did not
distinguish between public and private
wells. EPA estimated a total annual
treatment cost of approximately $6.7
million. EPA acknowledges an
uncertainty with this estimate of ±50
percent and believes that from 189 to
567 systems may be affected at a total
annual treatment cost ranging from $3.4
million to $10.1 million. EPA is retaining
these estimates of expected impact even
though the MCL decreases from the May
22.1989 level of 0.01 mg/1 to 0.003 mg/1
for aldicarb because the Agency
believes the State survey overestimated
the number of systems which would
require treatment. This conclusion is
supported by EPA's recently completed
National Pesticide Survey which did not
detect aldicarb in any wells at levels
exceeding 0.00071 mg/1. Based on a
statistical analysis, the National
Pesticide Survey report estimates a 95
percent chance that fewer than 750
community water system wells (or 375
community water systems) contain
aldicarb at levels which exceed the
survey's minimum reporting limit of
0.00071 mg/1. Annual treatment costs for
an individual system are estimated at
$10-14/household/yr for a large system
(serving > 1,000,000 people), $39/
household/yr for medium systems
(serving 10,000 to 25.000 people), and
$600/household/yr for a small system
(25 to 100 people).
Occurrence estimates for
pentachlorophenol are based on data
submitted by AWWA based on survey
data of 78 member utilities. This data
indicated that six utilities detected
pentachlorophenol at levels below 0.01
mg/1 and a seventh utility reported
pentachlorophenol at 0.02 mg/1 in
finished water. There are two basic
limitations to the AWWA data:
questionable or missing data were not
verified through QA/QC efforts and the
utility reporting the 0.02 mg/1 level in
finished water did not detect .
pentachlorophenol in its raw water.
Based on this data, EPA assumes that
825 systems will exceed the MCL for
• pentachlorophenol with a total national
treatment cost of $19 million per year.
EPA notes that the National Pesticide
Survey did not detect pentachlorophenol
in any wells. The survey report
estimates a 95 percent chance that fewer
than 375 community water systems will
exceed the NPS detection limit of
0.00001 mg/1. This National Pesticide
Survey estimate suggests that the
estimate of 825 systems which will
violate the MCL overestimates the true
impact. However, for this proposal, EPA
is retaining the estimate of 825 systems
and invites comment on this issue,
particularly data from surveys detecting
pentachlorophenol in drinking water at
levels above 0.00001 mg/1.
Small systems may qualify for
exemptions under section 1416(a). A
State or EPA may grant an exemption
extending deadlines for compliance with
a treatment technique or MCL if it finds
that (1) due to compelling factors (which
may include economic factors), the PWS
is unable to comply with the
requirement; (2) the exemption will not
result in an unreasonable risk to human
health; and (3) the system was in
operation on the effective date of the
NPDWR, or, for a system not in
operation on that date, no reasonable
alternative source of drinking water is
available to the new system.
Under section 1416(b)(2)(B) of the Act.
an exemption may be extended or
renewed (in the cases of systems that
serve less than 500 service connections
and that need financial assistance for
the necessary improvements) for one or
more two-year periods. EPA believes
that information on low-cost
technologies will receive a considerable
amount of attention over the next
several years and States giving
exemptions based on affordability
should be prepared to require small
water systems to regularly reexamine
the available technologies to ensure that
any new low-cost opportunities are
applied, where appropriate.
As stated earlier, EPA is not
reconsidering the costs for the proposed
VOC monitoring requirements because
those costs were considered in the final
Phase II rule promulgated elsewhere
today in the Federal Register. The costs
of today's proposed VOC monitoring
requirements have virtually no impact
on the total cost of VOC monitoring
primarily because a single analytical
method can analyze a range of
contaminants. Sampling for all VOC
contaminants can be conducted at the
same time.
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Federal Register / Vol. 56, No. 20 / Wednesday, January 30, 1991 / Proposed Rules
TABLE 3.—REGULATORY IMPACT
Contaminant
Aidicarb (including Sulfoxide and Sultone)
Pentachlorophenol
Barium ,
Systems in
violation
37B
825
0
Annual
treatment
cost
(Smillion/yr)
$6.7
$19
0
Typical treatment cost/system/year
Small '
600
600
$230-460 «
Medium 2
39
39
$54-160 <
Large3
10-14
'0
$26-110'
1 Small system serving 25-100 people.
* Medium system sen/ing 10,000-25.000 people. For Barium medium system serves 3,300-10,000 people.
3 Large systems serving more than 1,000.000 people.
4 Cost dependent upon BAT chosen.
B. Regulatory Flexibility Analysis
The Regulatory Flexibility Act
requires EPA to consider the effect of
regulations on small entities. 5 U.S.C.
602 et seq. If there is a significant effect
on a substantial number of small
systems, the Agency must prepare a
Regulatory Flexibility Analysis which
describes significant alternatives which
would minimize the impact on small
entities. An analysis of the impact on
small systems due to the MCL for
aidicarb is included in the RIA
supporting the final Phase II rule which
is promulgated elsewhere in today's
Federal Register. The Administrator has
determined that the proposed rule, if
promulgated, will not have a significant
effect on a substantial number of small
entities.
C. Paperwork Reduction Act
The information collection
requirements in this rule have been
submitted for approval to the Office of
Management and Budget (OMB) under
the Paperwork Reduction Act, 44 U.S.C.
3501 et seq as part of the information
collection requirements supporting the
final Phase II rule (which promulgates
MCLCs and MCLs for 35 contaminants),
which is promulgated elsewhere today
in the Federal Register. The information
collection requirements are not effective
until OMB approves them and a
technical amendment to that effect is
published in the Federal Register.
V. Request For Public Comment
E''A requests public analysis,
comments and information on all
aspects of this proposal. In particular,
the Agency is soliciting comment on the
following:
• Do the proposed VOC compliance
monitoring requirements serve the
purpose of insuring that high quality
water is available?
• Do the proposed MCLs adequately
consider the cost of treatment?
• Are there alternative VOC
monitoring requirements which would
still ensure high quality water but which
would be less burdensome for water
systems and States?
• Do the MCLs for aidicarb. aidicarb
sulfoxide, and aidicarb sulfone
represent a level which is protective of
public health?
• How should uncertainty factors be
chosen and used in providing an ample
margin of safety? What scientific and/or
policy rationales should be used to
choose uncertainty factors?
• Should EPA set the same MCLGs
for aidicarb and aidicarb sulfoxide, or
should the aidicarb sulfoxide MCLG be
different? If so, on what basis? Is it
appropriate from a scientific and/or
policy perspective?
• Are the assumptions and
uncertainty factors used to calculate the
aidicarb sulfone MCLG appropriate? Is
it scientifically sound to consider not
applying the additional three-fold
uncertainty factor in the derivation of
the aidicarb sulfone RfD either because
the human volunteer data on the parent
chemical and/or the lowest dose in the
sulfone dog study may be considered a
NOAEL rather than a LOAEL?
• EPA has approved EPA Method
531.1 as the approved analytical method
for aidicarb, aidicarb sulfoxide, and
aidicarb sulfone. Do other analytical
methods exist which can analyze these
chemicals?
• EPA estimates approximately 378
systems will violate the proposed MCL
for aidicarb. Is this estimate accurate?
• EPA is reproposing the MCL for
pentachlorophenol at a level of 0.001
mg/1, based upon a PQL of 0.001 mg/1.
Are there other MCLs EPA should
consider?
• EPA notes that at the proposed
pentachlorophenol MCL of 0.001 mg/1
approximately statistical 0.89 cancer
cases per year would be avoided.
Establishing an alternate MCL of 0.0001
mg/1 would result in an estimated
statistical 0.94 cases avoided. How
should estimates of additional cancer
cases avoided factor into EPA's analysis
of where to set the MCL? How should
costs factor into EPA's analysis of
where in the risk range (10~4 to 10"*) to
set the MCL?
List of Subjects in 40 CFR Pirts 141,142
and 143
Administrative practice and
procedure. Chemicals, Reporting and
recordkeeping requirements, Water
supply.
Dated: December 31.1990.
F. Henry Habicht,
Acting Administrator,
For the reasons set forth in the
preamble. Title 40 of the Code of Federal
Regulations is proposed to be amended
as follows:
PART 141—NATIONAL PRIMARY
DRINKING WATER REGULATIONS
1. The authority citation for part 14i
continues to read as follows:
Authority: 42 U.S.C. 300f. 300g-l. 300g-2,
300g-3, 300g-4. 300g-5, 300g-6. 300J-4 and
300J-9.
2. Section 141.24 is amended by
revising paragraphs (f). (g) introductory
text and (g)(8) introductory text to read
as follows:
§ 141.24 Organic chemicals other than
total trihalomethanes, sampling and
analytical requirements.
* * « • •
(f) Beginning on January 1,1993,
analysis of the contaminants listed in
§ 141.61(a) (1) through (18) for the
purpose of determining compliance with
the maximum contaminant level shall be
conducted as follows:
(1) Ground water systems shall take a
minimum of one sample at every entry
point to the distribution system wnich is
representative of each well after
treatment (hereafter called a sampling
point). If conditions warrant, the State
may designate additional sampling
points within the distribution system or
at the consumer's tap, which more
accurately determines consumer
exposure. Each sample must be taken at
the same sampling point unless
conditions make another sampling point
more representative of each source.
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Federal Register / Vol. 56, No. 20 / Wednesday, January 30, 1991 / Proposed Rules
3611
treatment plant, or within the
distribution system.
(2) Surface water systems (or
combined surface/ground) shall take a
minimum of one sample at points in the
distribution system that are
representative of each source or at each
entry point to the distribution system
after treatment (hereafter called e
sampling point). If conditions warrant.
the State may designate additional
points within the distribution system or
at the consumer's tap. which more
accurately determines consumer
exposure. Each sample must be taken at
the same sampling point unless
conditions make another sampling point
more representative of each source.
treatment plant, or within the
distribution system.
(3) If the system draws water from
more than one source and the sources
are combined before distribution, the
system must sample at an entry point to
the distribution system during periods of
normal operating conditions (i.e.. when
water representative of el! sources is
being used).
(4) Each community and non-transient
non-community water system shall take
four consecutive quarterly samples for
each contaminant listed in § 141.61(a)
(2) through (18) during each compliance
period, beginning in the compliance
period starting January 1.1993.
(5) Ground water systems which do
not detect one of the contaminants listed
in 5 141.61(a) (2) through (18) after
conducting the initial round of
monitoring required in paragraph (0(4)
of this section shall take one sample
annually.
(6) If the initial monitoring for ., ,
contaminants listed in § 141.61{a) (1) 'v
through (8) and the monitoring for the .
contaminants listed in § 14l.61(a) (9) •'
through (18) as allowed in paragraph
(0(18) of this section has been
completed by December 31,1992, and
the system did not detect any
contaminant listed in { 141.61(a) (1)
through (18). then the system shall take
one sample annually beginning January
1,1993. After a minimum of three years
of annual sampling, the State may allow
groundwater systems with no previous
detection of any contaminant listed in
§ 141.61(a) to take one sample during
each compliance period.
(7) Each community and non-transient
water which system does not detect a
contaminant listed in § 141.61(a) (1)
through (18) may apply to the State for a
waiver from the requirements of
paragraphs (0(4) and (f)(5) of this
section after completing the initial
monitoring. (For the purposes of this
section, detection is defined as >0.0005
mg/1.) A waiver shall be effective for no
more than six years (two compliance
periods).
(8) A State may grant a waiver after
evaluating the following factor(s):
(i) Knowledge of previous use
(including transport, storage, or
disposal) of the contaminant within the
watershed or zone of influence of the
system. If a determination by the State
reveals no previous use of the
contaminant within the watershed or
zone of influence, a waiver may be
granted.
(ii) If previous use of the contaminant
is unknown or it has been used
previously, then for the following factors
shall be used to determine whether a
waiver is granted.
(A) Previous analytical results.
(B) The proximity of the system to a
potential point or non-point source of
contamination. Point sources include
spills and leaks of chemicals at or near a
water treatment facility or at
manufacturing, distribution, or storage
facilities, or from hazardous and
municipal waste landfills and other
waste handling or treatment facilities.
(C) The environmental persistence
and transport of the contaminants.
(D) The number of persons served by
the public water system and the
proximity of a smaller system to a larger
system.
(E) How well the water source is
protected against contamination, such
as whether it is a surface or
groundwater system. Groundwater
systems must consider factors such as
depth of the well, the type of soil, and
wellhead protection. Surface water
systems must consider watershed
protection.
(9) As a condition of the waiver a
system must take one sample at each
sampling point during the time the
waiver is effective (i.e., one sample
during two compliance periods or six
years) and update its vulnerability
assessment considering the factors
listed in paragraph (f)(8) of this section.
Based on this vulnerability assessment
the State must reconfirm that the system
is non-vulnerable. If the State does not
make this reconfirmation within three
years of the initial determination, then
the waiver is invalidated and the system
is required to sample annually as
specified in paragraph (0(5) of this
section.
(10) A surface water system which
does not detect a contaminant listed in
§ 141.61(a) (1) through (18) and is
determined by the State to be non-
vulnerable using the criteria in
paragraph (f)(8) of this section shall
monitor at the frequency specified by
the State (if any). Systems meeting this
criteria must be determined by the State
to be non-vulnerable based on a
vulnerability assessment during each
compliance period.
(11) If a contaminant listed in
§ 141.61(a) (2) through (16) is detected at
a level exceeding 0.0005 mg/1 in any
sample, then:
(i) The system must monitor quarterly
at each sampling point which resulted ir.
a detection.
(ii) The State may decrease the
quarterly monitoring requirement
specified in paragraph (f)(H)(i) of this
section provided it has determined that
the system is reliably and consistently
below the maximum contaminant level.
In no case shall the State make this
determination unless a groundwater
system takes a minimum of two
quarterly samples and a surface water
system takes a minimum of four
quarterly samples.
(iii) If the State determines that the
system is reliably and consistently
below the MCL, the State may allow the
system to monitor annually. Systems
which monitor annually must monitor
during the quarters) which previously
yielded the highest analytical result.
(iv) Systems which have three
consecutive annual samples with no
detection of a contaminant may apply to
the State for a waiver as specified in
paragraph (0(7) of this section.
(v) Groundwater systems which have
detected one or more of the following
two-carbon organic compounds:
trichloroethylene, tetrachloroethylene,
1.2-dichloroethane. 1,1,1-trichloroethane.
cis-l.Z-dichloroethylene, trans-1.2-
dichloroethylene, or 1,1-
dichloroethylene shall monitor quarterly
for vinyl chloride. A vinyl chloride
sample shall be taken at each sampling
point at which one or more of the two-
carbon organic compounds is detected.
If the results of the first analysis do not
detect vinyl chloride, the State may
reduce the quarterly monitoring
frequency of vinyl chloride moni taring -
to one sample during each compliance
period Surface water systems are
required to monitor for vinyl chloride as
specified by the State.
(12) Systems which violate the
requirements of § 141.61(a) (1) through
(18), as determined by paragraph (f)(16)
of this section, must monitor quarterly.
After a minimum of four quarterly
samples which show the system is in
compliance as specified in paragraph
(f}(15) of this section the system and the
State determines that the system is
reliably and consistently below the
maximum contaminant level, the system
may monitor at the frequency and time
specified in paragraph (f)(ll)(iii) of this
section.
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Federal Register / Vol. 56, No. 20 / Wednesday, January 30. 1991 / Proposed Rules
(13) The State may require a
confirmation sample for positive or
negative results. If a confirmation
sample is required by the State, the
result must be averaged with the first
sampling result and the average is used
for the compliance determination as
specified by paragraph (f)(16) of this
section. States have discretion to delete
results of obvious sampling errors from
this calculation.
(14) The State may reduce the total
number of samples a system must
analyze by allowing the use of
compositing. Composite samples from a
maximum of five sampling points are
allowed. Compositing of samples must
br; done in the laboratory and analyzed
within 14 days of sample collection.
(i) If the concentration in the
composite sample is >0.0005 mg/1 for
any contaminant listed in § 141.61(a),
then a follow-up sample must be taken
and analyzed within 14 days from each
sampling point included in the
composite.
(ii) If duplicates of the original sample
taken from each sampling point used in
the composite are available, the system
may use these instead of resampling.
The duplicate must be analyzed and the
results reported to the State within 14
days of collection.
(iii) Compositing may only be
permitted by the State at sampling
points within a single system, unless the
population served by the system is
< 3,300 persons. In systems serving
< 3,300 persons, the State may permit
compositing among different systems
provided the 5-samp!e limit is
maintained.
(iv) Compositing samples prior to GC
analysis.
(A) Add 5 ml or equal larger amounts
of each sample (up to 5 samples are
allowed) to a 25 ml glass syringe.
Special precautions must be made to
maintain zero headspace in the syringe.
(B) The samples must be cooled at 4°C
during this step to minimize
volatilization losses.
(C) Mix well and draw out a 5-ml
aliquot for analysis.
(D) Follow sample introduction.
surging, and desorption steps described
in the method.
(E) If less than five samples are used
for compositing, a proportionately small
syringe may be used.
(v) Compositing samples prior to GC/
MS analysis.
(A) Inject 5-ml or equal larger
amounts of each aqueous sample (up to
5 samples are allowed) into a 25-ml
purging device using the sample
introduction technique described in the
method.
(B) The total volume of the sample in
Ihe purging device must be 25 ml.
(C) Purge and desorb as described in
the method.
(15) Compliance with § 141.61(a)[l)
through (18) shall be determined based
on the analytical results obtained at
each sampling point.
(i) For systems which are conducting
monitoring at a frequency greater than
annual, compliance is determined by a
running annual average of all samples
taken at each sampling point. If the
annual average of any sampling point is
greater than the MCL, then the system is
out of compliance. If the initial sample
or a subsequent sample would cause the
annual average to be exceeded, then the
system is out of compliance
immediately.
(ii) If monitoring is conducted
annually, or less frequently, the system
is out of compliance if the level of a
contaminant at any sampling point is
greater than the MCL. If a confirmation
sample is required by the State, the
determination of compliance will be
based on the average of two samples.
(iii) If a public water system has a
distribution system separable from other
parts of the distribution system with no
interconnections, the State may allow
the system to give public notice to only
that area served by that portion of the
system which is out of compliance.
(16) Analysis for the contaminants
listed in § 141.61(a)(l) through (18) shall
be conducted using the following EPA
methods or their equivalent as approved
by EPA. These methods are contained in
"Methods for the Determination of
Organic Compounds in Drinking Water",
ORD Publications, CERI, EPA/600/4-88/
039, December 1988. These documents
are available from the National
Technical Information Service (NTIS),
U.S. Department of Commerce. 5285 Port
Royal Road, Springfield, Virginia 22161.
The toll-free number is 800-336-4700.
(i) Method 502.1. "Volatile
Halogenated Organic Chemicals in
Water by Purge and Trap Gas
Chromatography."
(ii) Method 502.2. "Volatile Organic
Compounds in Water by Purge and Trap
Capillary Column Gas Chromatography
with Photoionization and Electrolytic
Conductivity Detectors in Series."
(iii) Method 503.1. "Volatile Aromatic
and Unsaturated Organic Compounds in
Water by Purge and Trap Gas
Chromatography."
(iv) Method 524.1, "Measurement of
Purgeable Organic Compounds in Water
by Purged Column Gas
Chromatography/Mass Spectrometry."
(v) Method 524.2, "Measurement of
Purgeable Organic Compounds in Water
by Capillary Column Gas
Chromatography/Mass Spectrometry."
(17) Analysis under this section shall
only be conducted by laboratories that
have received approval by EPA or the
State according to the following
conditions:
(i) To receive conditional approval to
conduct analyses for the contaminants
in § 141.61(a)(2) through (18) the
laboratory must:
(A) Analyze Performance Evaluation
samples which include these substances
provide by EPA Environmental
Monitoring and Support Laboratory or
equivalent samples provided by the
State.
(B) Achieve the quantitative
acceptance limits under paragraphs
(f)(18)(i)(C) and (D) of this section for at
least 80 percent of the regulated organic
chemicals listed in § 141.61(a)(2) through
(18).
(C) Achieve quantitative results on
the analyses performed under paragraph
(f)(18)(i)(A) of this section that are
within ±20 percent of the actual amount
of the substances in the Performance
Evaluation sample when the actual
amount is greater than or equal to 0.010
mg/1.
(D) Achieve quantitative results on
the analyses performed under paragraph
(f)(18)(i)(A) of this section that are
within ±40 percent of the actual amount
of the substances in the Performance
Evaluation sample when the actual
amount is less than 0.010 mg/1.
(E) Achieve a method detection limit
of 0.0005 mg/1, according to the
procedures in Appendix B of part 136 of
this chapter.
(F) Be currently approved by EPA or
the State for the analyses of
trihalomethanes under § 141.30.
(ii) To receive conditional approval
for vinyl chloride, the laboratory must:
(A) Analyze Performance Evaluation
samples provided by EPA
Environmental Monitoring and Support
Laboratory or equivalent samples
provided by the State.
(B) Achieve quantitative results on the
analyses performed under (paragraph)
(f){17)(ii)(A) of this section that are
within si40 percent of the actual amount
of vinyl chloride in the Performance
Evaluation sample.
(C) Achieve a method detection limit
of 0.0005 mg/i, according to the
procedures in appendix B of part 136 of
this chapter.
(D) Receive approval or be currently
approved by EPA or the State under
paragraph (g)(ll)(i) of this section.
(18) States may allow the use of
monitoring data collected after Januarv
1,1988 required under section 1445 of
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Federal Register / Vol. 56, No. 20 / Wednesday, January 30. 1991 / Proposed Rules
3613
the Act for purposes of monitoring
compliance. If the data are generally
consistent with the other requirements
in this section, the State may use these
data (i.e.. a single sample rather than
four quarterly samples) to satisfy the
initial monitoring requirement of
paragraph (f)(4) of this section.
(19) States may increase required
monitoring where necessary to detect
variations within the system.
(20) Each approved laboratory must
determine the method detection limit
(MDL). as defined in appendix B to part
136 of this chapter, at which it is capable
of detecting VOCs. The acceptable MDL
is 0.0005 mg/1. This concentration is the
detection concentration for purposes of
this section.
(21) Each public water system shall
monitor at the time designated by the
State within each compliance period.
* • • • •
(g) For systems in operation before
January 1,1993, for purposes of initial
monitoring, analysis of the contaminants
listed in § 141.61(a) for purposes of
determining compliance with the
maximum contaminant levels shall be
conducted as folows:
* * * * •
(8) Until January 1.1S93. the State
may reduce the monitoring frequency in
paragraph (g)(l) and (g)(2) of this
section, as explained in this paragraph.
*****
4. In § 141.32, paragraphs (e) (16), (25)
through (27), and (e)(45) are added and
paragraph (e) (13) through (14) are
reserved to read as follows:
S 142.32 I Amended)
*****
(e)' • '
(13H14) [Reserved]
(16) Barium. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that barium is a health
concern at certain levels of exposure.
This inorganic chemical occurs naturally
in some aquifers that serve as sources of
ground water. It is also used in oil and
gas drilling muds, automotive paints.
bricks, tiles and jet fuels. It generally
gets into drinking water after dissolving
from naturally occurring minerals in the
ground. This chemical may damage the
heart and cardiovascular system, and is
associated with high blood pressure in
laboratory animals such as rats exposed
to high levels during their lifetimes. In
humans. EPA believes that effects from
barium en blood pressure should not
occur below 10 ppm in drinking water.
EPA has set the drinking water standard
for barium at 2 parts per million (ppm) to
protect against the risk of these adverse
health effects. Drinking water that meets
the EPA standard is associated with
little to none of this risk and is
considered safe with respect to barium.
• * * * *
(25) Aldicarb. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that aldicarb is a health
concern at certain levels of exposure.
Aldicarb is a widely used pesticide.
Under certain soil and climatic
conditions (e.g., sandy soil and high
rainfall), aldicarb may leach into ground
water after normal agricultural
applications to crops such as potatoes or
peanuts or may enter drinking water
supplies as a result of surface runoff.
This chemical has been shown to
damage the nervous system in
laboratory animals such as rats exposed
to high levels. EPA has set the drinking
water standard for aldicarb at 0.003
parts per million (ppm) to protect
against the risk of adverse health
effects. Drinking water that meets the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to aldicarb.
(26) Aldicarb sulfoxide. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that aldicarb sulfcxide
is a health concern at certain levels of
exposure. Aldicarb is a widely used
pesticide. Aldicarb sulfoxide in ground
water is primarily a breakdown product
of aldicarb. Under certain soil and
climatic conditions (e.g., sandy soil and
high rainfall), aldicarb sulfoxide may
leach into ground water after normal
agricultural applications to crops such
as potatoes or peanuts or may enter
drinking water supplies as a result of
surface runoff. This chemical has been
shown to damage the nervous system in
laboratory animals such as rats exposed
to high levels. EPA has set the drinking
water standard for aldicarb sulfcxide at
0.003 parts per million (ppm) to protect
against the risk of adverse health
effects. Drinking water that meets the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to aldicarb sulfoxide.
(27) Aldicarb sulfone. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that aldicarb sulfone is
a health concern at certain levels of
exposure. Aldicarb is a widely used
pesticide. Aldicarb sulfone is formed
from the breakdown of aldicarb and is
considered for registration as a pesticide
under the name aldoxycarb. Under
certain soil and climatic conditions (e.g.,
sandy soil and high rainfall), aldicarb
sulfone may leach into ground water
after normal agricultural applications to
crops such as potatoes or peanuts or
may enter drinking water supplies as a
result of surface runoff. This chemical
has been shown to damage the nervous
system in laboratory animals such as
rats exposed to high levels. EPA has set
the drinking water standard for aldicarb
sulfone at 0.003 parts per million (ppm)
to protect against the risk of adverse
health effects. Drinking water that meets
the EPA standard is associated with
little to none of this risk and is
considered safe with respect to aldicarb
sulfone.
• • • * *
(46) Pcntachloropheno!. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that peniachloropheno!
is a health concern at certain levels of
exposure. This organic chemical is used
as a wood preservative, herbicide,
disinfectant, and defoliant. It generally
gets into drinking water by runoff into
surface water or leaching into ground
water. This chemical has been shown to
produce adverse reproductive effects
and to damage the liver and kidneys of
laboratory animals such as rats exposed
to high levels during their lifetimes.
Some humans who were exposed to
relatively large amounts of this chemical
also suffered damage to the liver and
kidneys. EPA has set the drinking water
standard for pentachlorophcnol at 0.001
parts per million (ppm) to protect
against the risk cf these adverse health
effects. Drinking water that meets the
EPA standard is associated with little to
none cf this risk and is considered safe
with respect to pentachlorophenol.
*****
5. Section 141.50 is amended in the
table by adding paragraphs (a)(15),
(b)(4). (b)(5). and (b)(6) to read as
follows:
§ 141.50 Maximum contaminant level
goals lor organic chemicals.
(a) * * •
(15) Pentachlorophenol
(b) * * '
Contaminant
MCLG
(mg/l)
(4) Aldicarb 0.001
(5) Aldicarb sulfoxide 0.001
(6) Aldicarb suttone 0.002
6. Section 141.51 is amended by
adding (b)(3) to read as follows:
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3814
Federal Register / Vol. 56, No. 20 / Wednesday, January 30. 1991 / Proposed Rules
§ 141.51 Maximum contaminant level
goals for inorganic contaminants.
(b) * * '
Contaminant
MCLG
(mg/l)
(3) Barium..
7. Section 141.61 is amended by
adding paragraphs (c)(2), (c)(3), (c){4),
and (c)(16) to read as follows:
§ 141.61 Maximum contaminant levels (or
organic contaminants.
* * * « •
(c)' ' *
CAS No.
Contaminant
MCL
(mg/l)
(2)116-06-3 Aldicarb 0.003
(3) 1646-87-3 Aldicart) sulfoxide 0.003
(4)1646-87-4 Aldicart) suHone 0.003
CAS No.
Contaminant
MCL
(mg/l)
(16)87-86-5 Penlachlorophenot 0.001
8. Section 141.62 is amended by
adding paragraph (b)(3) to read as
follows:
§ 141.62 Maximum contaminant levels for
inorganic contaminants.
(b) * * *
Contaminant
MCL
(mg/l)
(3) Barium..
PART 142—NATIONAL PRIMARY
DRINKING WATER REGULATIONS-
IMPLEMENTATION
1. The authority citation for part 142
continues to read as follows:
Authority: 42 U.S.C. 300g. 300g-l. 300g-2.
300g-3. 300g-4. 300g-5. 300g-6. 300J-4 and
300J-9-
2. Section 142.62 is amended by
redesignating existing paragraphs (e),
(f). (8). and (h) as (f), (g). (h). and (i) and
by adding a new paragraph (e) to read
as follows:
§ 142.62 Variances and exemptions from
the maximum contaminant levels for
organic and Inorganic chemicals.
• * * • *
(e) If a system serving fewer than
3,300 people can demonstrate in
accordance with criteria published by
EPA. that none of the treatment methods
identified in 5 142.62(a)(9)-(36) and
1142.62(b) is affordable, the system
shall be eligible for a variance under the
provisions of section 1415(a)(l)(A).
• * • * *
|FR Doc. 91-934 Filed 1-29-91; 8:45
-------
Monday
July 1, 1991
Part XII
Environmental
Protection Agency
40 CFR Parts 141, 142, and 143
National Primary Drinking Water
Regulations; Final Rule
-------
£0266 Federal Register / Vol. 56. No. 126 / Monday. July 1, 1991 / Rules and Regulations
ENVIRONMENTAL PROTECTION
AGENCY
JO CFR Part 141,142 and 143
R!N 2040-AA55
[FRL-3060-11
Drinking Water; National Primary
Drinking Water Regulations;
Monitoring for Volatile Organic
Chemicals; MCLGs and MCLs for
Aldicarb, Aldlcarb Sulfoxide, Aldicarb
Sulfone, Pentachlorophenol, and
Barium
AGENCY: Environmental Protection
Agency (EPA).
ACTION: Final rule.
SUMMARY: In this notice. EPA is revising
monitoring requirements for eight
volatile organic contaminants (VOCs)
originally promulgated July 8,1987. This
change synchronizes requirements for
these eight VOCs with monitoring
requirements for VOCa promulgated on
January 30,1991 (56 FR 3528). EPA is
also promulgating the MCLGs and MCLs
for aldicarb, aldicarb sulfoxide. aldicarb
sulfone, pentachlorophenol. and barium.
This Notice also corrects errors and
clarifies certain issues in the final rule
promulgating 33 National Primary
Drinking Water Regulations
promulgated January 30.1991 (56 FR
3526).
EFFECTIVE DATE: The amendments to
§ 141.6, paragraph (c) of the table in
§ 141.12. and $ 141.62(b)(l) are effective
July 1.1991. The amendments to
§§ 141.11(b). 141.23.141.24,142.57.
I43.4(b)(12) and (b)(13). are effective
July 30,1992. The revisions to
§ 141.32(e)(16), (25) through (27) and (46):
§ 141.50(a)(15). (b)(4). fb)(5) and (b)(6);
§ 141.51(b)(3); § 141.61(c)(2). (c)3. (c)(4)
and (c)(16); § 141.62(b)(3) are effective
January 1.1993.
The barium information collection
requirements of $ 141.23 are effective
January 1.1993. if the information
Collection Request is cleared by the
Office of Management and Budget
(OMB). If not, EPA will publish a
document delaying the effective date of
the barium information collection
requirements. Otherwise, the
requirements will be effective when
OMB clears the request at which time a
document will be published in the
Federal Register establishing the
effective date.
In accordance whh 40 CFR 23.7, this
regulation shall be considered final
Agency action for the purptftesof
judicial review at 1 p.m.. Eastern time on
July 15.1991.
ADDRESSES: A copy of the public
comments received, EPA responses, and
all other supporting documents
(including references included in this
notice) are available for review at the
U.S. Environmental Protection Agency
(EPA). Drinking Water Docket 401 M
Street. SW., Washington, DC 20460. For
access to the docket materials, call 202-
382-3027 between 9 a.m. and 3:30 p.m.
Any document referenced by an MRID
number is available by contacting Susan
Laurence. Freedom of Information
Office. Office of Pesticide Programs, at
703-557-4454.
Copies of health criteria, analytical
methods, and regulatory impact analysis
documents are available for a fee from
the National Technical Information
Service (NTIS), U.S. Department of
Commerce. 5285 Port Royal Road,
Springfield. Virginia 22161. The toll-free
number is 800-336-4700, local: 703-487-
4650.
FOR FURTHER INFORMATION, CONTACT:
Al Havinga, Standards Division. Office
of Ground Water and Drinking Water
(WH-550), U.S. Environmental
Protection Agency. 401 M Street SW..
Washington, DC 20460. 202/382-5555.
General information may also be
obtained from the EPA Drinking Water
Hotline. The toll-free number is 800/426-
4791. Alaska and local: 202/382-5533.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Statutory Authority
II. Regulatory Background
III. Explanation of Today's Action
A. VOC Monitoring Requirements
1. Standardized Monitoring Framework
2. Sampling Points
3. Initial and Repeat Base Monitoring
Requirements
4. Increased Monitoring
5. Vulnerability Assessments and Waivers
B. Aldicarb. Aldicarb Sulfoxide. and
Aldicarb Sulfone
1. Aldicarb. Aldicarb Sulfoxide. and
Aldicarb Sulfone MCLGs
2. Aldicarb. Aldicarb Sulfoxide. and
Aldicarb Sulfone MCLs
C. Pentachlorophenol
1. Pentachlorophenal MCLC
2. Pentachlorophenol MCL
D. Barium
1. Barium MCLC
2. Barium MCL
E. 1415 Variance Option
F. Analytical Methods
C. Corrections to the January 30.1991
Notice
IV. Economic Analysis
A. Regulatory Impact
B. Regulatory Flexibility Analysis
C. Paper Work Reduction Act
I. Statutory Authority
The Safe Drinking Water Act
("SDWA" or "the Act"), as amended in
1986 (Pub. L. 99-339.100 Stat. 642).
requires EPA to publish "maximum
contaminant level goals" (MCLGs) for
contaminants which, in the judgment of
the Administrator, "may have any
adverse effect on the health of persons
and which [are] known or anticipated to
occur in public water systems" (section
1412(b)(3)(A)). MCLGs are to be set at a
level at which "no known or anticipated
adverse effects on the health of persons
occur and which [allow] an adequate
margin of safety" (see section
1412(b)(4)J.
At the same time EPA publishes an
MCLG, which is a non-enforceable
health goal, it must also promulgate a
National Primary Drinking Water
Regulation (NPDWR) which includes
either (1) a maximum contaminant level
(MCL), or (2) a required treatment
technique (section 1401(1), 1412(a)(3),
and 1412(b)(7)(A)). A treatment
technique may be set only if it is not
"economically or technologically
feasible" to ascertain the level of a
contaminant (sections 1401(1) and
1412(b)(7)(A)). An MCL must be set as
close to the MCLG as feasible (section
1412(b)(4)). Under the Act "feasible"
means "feasible with the use of the best
technology, treatment techniques and
other means which the Administrator
finds are available, after examination
for efficacy under field conditions and
not solely under laboratory conditions
(taking cost into consideration)" (sectio
1412(b)(5)). NPDWRs also include
monitoring, analytical and quality
assurance requirements, specifically,
"criteria and procedures to assure a
supply of drinking water which
dependably complies with such
maximum contaminant levels
(section 1401(1)(D)). Section 1445 of
SDWA also authorizes EPA to
promulgate monitoring requirements.
II. Regulatory Background
On July 8.1987 EPA promulgated
NPDWRs for eight volatile organic
contaminants (VOC rule. 52 FR 25690).
On May 22.1989 EPA proposed VOC
monitoring requirements for 10
contaminants and MCLGs and MCLs for
38 contaminants including aidicarb.
aldicarb sulfoxide, aldicarb sulfone.
pentachlorophenol. and barium. The
MCLGs and MCLs for these five
chemicals were reproposed on January
30.1991 (56 FP, 3600) at different levels
due to information which was received
and/or analyzed by the Agency
subsequent to the May 22.1989
proposal.
The monitoring requirements outlined
in today's rule for the most part mirror
(with several exceptions, as noted
below) the VOC requirements published
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Bagtete/'VoL SB. No. 126 / Monday, July 1. 1991 / Rules and Regulations
on January 30, 1991 for tbe 10 VOGs i»
the Phase II rule. EPA stated to the
reproposal that changes to the proposal
incorporated in the final rule would
apply to monitoring requirements for
both the 10 VOCs promulgated January
30. 1991 and the 6 VOOi included in
today's rule. This enaerea the monitoring
requirements for die 18 VOC» (the a
Phase I VOCs and die 10 Phase fl VOCs)
remain identical Consequeatiy. the
changes published today will also apply
to the monitoring requirements for the 10
Phase II VOCs published January 30.
1991.
IIL Explanation of Today's Action
A. VOC Monitoring Requirements
1. Standardized Monitoring Framework
In response to comments received on
the May 22, 1989 Phase H proposed role.
EPA developed a standarired
monitoring framework to address the
issues of complexity, coordination
between various regulations, and
s ynchonrzation of monltomg schedules.
EPA stated that this framework would
-
serve as a guide for future
related monitoring requirements
adopted by the Agency.
Comments submitted to EPA during
the comment period revealed support for
the standardized monitoring framework.
Within this standardized framework
each State must designate
approximately one-third of the systems
to conduct initial monitoring during each
year of the initial compliance period (Le.
one third in 1993. one-third in 1994 and
one third in 1995). This arrangement is
intended to level the anticipated
workload.
Most commenters believed that the
framework does achieve the goals of
synchronization of monitoring
schedules. Most comments rechred by
the Agency addressed specific issues
related to changes in die VOC
monitoring requirements and how the
1987 VOC requirements will be
coordinated with the Phase U
requirements promulgated January 30.
1991.
The monitoring requirements outlined
in today's rule for the most part mirror
(with several exceptions as discussed
"below) the VOC requirements
promulgated in January 1991 for 10
VOCs. EPA stated in the proposal for
todays rule that if comments and
information received during the
comment period result in changes to this
proposal. EPA will promulgate a final
rule which will also apply to monitoring
requirements for the 10 VOCs
promulgated on January 3D. This ensures
(hat the monitoring requiremerlQrfor the
18 VOCs (the 8 Phase I and 10 Phase II
VOCs) remain ideatieaL Consequently.
the changes promulgated today will also
apply to die monitoring requirements for
the 10 VOCs published January 30.1991.
2. Sampling Points
In the proposal EPA stated that the
Agency had received information
suggesting that petroleum and
hazardous material spills and leaks
have contributed to drinking water
contamination in systems using plastic
pipe. EPA stated that it is concerned
about this issue because this
contamination typically occurs after the
designated sampling point and
consequently would not be detected. As
a result EPA proposed in §141.24 (f) (1)
and (2) that "if conditions warrant the
State may designate additional sampling
points within the distribution system or
at the consumer's tap. which more
accurately determines consumer
exposure;"
Most comments received on the
proposed change to the sampling points
opposed the concept Objections raised
by commenters addressed three major
issues (1) Whether the SOWA granted
EPA the legal authority to require
sampling at the consumer's tap; (2)
permeation of plastic pipe typically
occurs in service lines and thus is
generally within the consumer's control:
and (3) the Agency failed to specify best
available technology to address this
problem. While not agreeing with these
comments, the Agency has decided to
give further consideration to options
addressing the issue of VOC permeation
of plastic pipe. Accordingly, EPA has
dropped this proposed monitoring
provision in the final rule. As noted
above, because the Agency intends that
the VOC monitoring requirements are
identical this decision to withdraw the
changes in the sampling points will also
apply to the final rule published January
30,1991. The Agency intends to address
this issue in a subsequent rulemaking
seeking additional information and
solutions to the permeation issue.
3. Initial and Repeat Base Monitoring
Requirements
In the VOC regulations promulgated
In July 1987. distinctions in base (or
minimum) requirements were made
between ground and surface water
systems, systems which have more than
or less than 500 service connections, and
vulnerable/non-vulnerable systems. In
streamlining the requirements. EPA
proposed that all systems (regardless of
system size) take four quarterly samples
each compliance period. After the initial
round of four quarterly samples, all
systems which do not detect VOCs in
the initial round of quarterly sampling
wouid-aianttor annually beginning ia the
next calendar year alter quarterly
sampling is completed. Ground water
systems which conducted at least three
years of annual and/or quarterly
sampling and did not detect any VOCs
would be allowed to reduce the
sampling frequency to a single sample
every three years. EPA also proposed
that systems could grandfather f"Tifa>g
results from me Section 1445 monitoring
for unregulated contaminants for the
initial compliance period even if only
one sample rather than 4 quarteriy
samples ware analyzed in the initial
compliance period.
EPA received several comments
disagreeing with die requirement that
systems take four quarterly samples
during die initial compliance period
These commenters cited die regulatory
impact on smaH systems and non-
transient water systems. In addition, one
commenter suggested that "use" should
be considered to deteiiauMag thsftattiai
sampling frequency. AnodureoBBBanter
stated that fafcreasfeg the sasspteg
frequency to annual (ramer thaaevery 3
years) was a major policy shift and
would have an adverse impact on small
systems.
EPA continues to believe mat 4
quarterly samples are necessary to
establish a baseline of analytical results
for any VOCs which occur with
sufficient frequency. However, we note
that because all systems mast have
completed their initial round of
monitoring by January 1992 under
existing requirements in 5 141.24(g)
(monitoring for 8 regulated
contaminants) and i 141.40 (monitoring
for unregulated VOC contaminants), the
initial monitoring requirements (La* 4
quarterly »amptes) wiU only app>4»
new systems or those systems wMck
have a new source. Most system* will
be able to begin annual monitoring in
January 1993 if the initial campling
results are grandfathered. We feel that
initial sampling frequency based upon
"use" is not practical or protective of
public health because available
occurrence data indicate that VOCs are
found In virtually all geographic areas in
the United States.
4. Increased Monitoring
In the 1987 VOC rule, systems which
detect VOCs (defined as any analytical
result greater than 0.0005 mg/1) were
required to monitor quarterly. Several
commenters believed that this
regulatory minimum detection limit was
too low and should alternately be 50% or
BOXoftheMCL.
EPA notes that the 0.0005 mg/1
requirement has been in effect since the
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30268 Federal Register /Vol. 56. No. 128 / Monday, July 1. 1991 / Rules and Regulations
1987 VOC -i'.e. This requirement serves
to give early indication that
contamination has occurred before a
violation occurs. EPA acknowledges
that false positives might rarely occur
(i.e., less than one percent of the time)
with a detection limit of 0.0005 mg/1.
I lowever. v/s note that requirements in
§ 141.24 (0(13) also allow the State to
require confirmation samples for
positive or negative results. In addition.
the State has the option to delete results
'.-•f obvious sampling errors. EPA
believes that States have sufficient
discretion to address the issue of false
positives through these provisions.
Another commenter argues that
waivers will be difficult to obtain
because of unreasonably low detection
limits. EPA regulations do not allow
systems which have detected VOCs to
receive waivers because even detecting
contamination is evidence that the
system is vulnerable. This
contamination should be farther
examined by additional monitoring.
Several commenters objected to the
provision which allows States to reduce
the sampling frequency of systems
which detect contamination. One
commenter believed that this
determination should not be made for
Ground water systems until four quarters
of monitoring have elapsed. EPA
believes that the proposed requirement
that the State determine the system is
"reliably and dependably" below the
MCL is protective of health. The two
quarter requirement is sufficient as a
minimum standard but we note that
ihe.-e may be situations where
additional monitoring (beyond the two
quarter/four quarter minimum) will be
necessary to establish a baseline. In
these cases, if the State does not make
the "reliably and dependably"
determination, systems will be required
to continue to monitor quarterly.
r>. Vulnerability Assessments and
Waivers
Most cor.-.menters agreed with the
concept of vulnerability assessments
and waivers particularly the provision
for a separate vulnerability decision by
consideration of use and susceptibility.
Several commeniers noted that the shift
-f responsibility from States to water
systems io conduct vulnerability
assessments could result in waivers
being unavailable for small systems.
Several commenters stated that
additional guidance was necessary to
•••nsufe systems know how to conduct
vulnerability assessments.
As stated in the proposal, EPA shifted
the responsibility to conduct!*"--. -^
vulnerability assessments from States to
water systems because we believe that
these assessments are part of the
systems' monitoring responsibilities. In
addition, previous comments indicated
that State resource constraints
precluded the conduct of vulnerability
assessments. Consequently, EPA shifted
the responsibility to conduct
vulnerability assessments to water
systems. EPA agrees with the
commenters that additional guidance on
how to conduct vulnerability
assessments is needed and is currently
developing such guidance. This guidance
will be completed and made available to
water systems and States prior to the
compliance period which begins January
1,1993.
Our goals are to efficiently utilize
State and PWS resources and to be
consistent with Phase II monitoring
requirements. EPA believes that today's
pjie furthers these goals.
B, Aldicarb. Aldicarb Sulfoxide and
Aldicarb Suifone
1. Aldicarb, Aldicarb Sulfoxide and
Aldicarb Suifone MCLGs
On January 30,1991 EPA reproposed
MCLGs for aldicarb, aldicarb sulfoxide,
and aldicarb sulfone at 0.001, 0.001, and
0.002 mg/kg/day. The MCLG for each of
the three chemicals was based on a
revised RfD adopted in August 1990 that
reflected non-cancer cndpoints of
toxicity, cholinesterase inhibition
(ChCI), and, for the parent compound
(aldicarb), clinical signs in animals (soft
rr.ucoid stool and diarrhea) and humans
(nausea, vomiting and diarrhea in some
sensitive individuals were noted in
epidemiological data). Cancer
classification is Group D (inadequate
human evidence of carcinogenicity).
Public Comments
EPA has previously addressed the
public comments received in response to
the proposals of November 13.1985 and
May 22.1989 in the Federal Register
notice of January 30.1991 (56 FR 3600).
Four commsnters responded to the
January 1991 proposal. One commenter
argued that EPA's RfD of 0.0002 mg/kg/
day used in developing the proposed
aldicarb MCLG is legally and
scientifically unsupportablc. In support
cf this position, ths commenter cited the
May 23,1990 recommendation of the
joint study group of the Agency's
Science Advisory Board and Scientific
Advisory Panel (SAB/SAP) that ChEI is
not an adverse effect and therefore
should not be the basis of EPA
regulation for aldicarb. One ccmmenter
advised that the Agency establish the
MCLG and MCL for aidicarb and the
sulfoxide metabolite based on the
Haines (1971) human study. This
commenter suggested using the NOAEL
for clinical signs in this study. 0.05 mg/
kg, and a 10-fold uncertainty factor (UF)
to establish the MCLG. For aldicarb
sulfone, this commenter indicated that
the lowest dose tested in the one-year
dog feeding study (Hazleton Labs, 1987),
0.11 mg/kg/day. is the NOAEL and
should be used with a 10-fold UF to
establish the MCLG for aldicarb sulfone.
Two additional commenters agreed
with the position expressed by the first
commenter relative to the SAB/SAP
recommendation on ChEI as only a
marker of exposure, and that the Agency
should not lower the RfD for aldicarb.
However, one of these two commenters
noted that the MCLG should be based
on child exposure.
A fourth commenter indicated that the
reproposed MCLGs for aldicarb,
aldicarb sulfoxide. and aldicarb sulfone,
based on the revised RfD of 0.0002 mg/
kg/day, may not provide a sufficient
margin of safety against acute toxic
symptoms in the general population at
levels as low as 0.0011 mg/kg/day.
The first commenter also noted that
establishing an MCLG based on ChEI is
inconsistent with the Agency regulation
for fluoride and silver.
Response to Public Comments
Aldicarb and aldicarb suifoxide. The
Agency reproposed an MCLG of 0.001
mg/1 for aidicarb and aldicarb sulfoxide
based on a revised RfD of 0.0002 ng/kg/
day (July, 1990), as described in the
January 30,1991 Notice (56 FR 3804).
This RfD was based on clinical effects
and cholinesterase inhibition (ChEI) in
animals and humans following exposure
to aldicarb. The Agency sought public
comment on considering both nHnir.nl
signs and ChEI in setting the RfD and. in
turn, the MCLG.
Many of the studies considered in the
risk assessment for both aldicarb and
aldicarb sulfoxide reported ChEI in
exposed humans or animals.
Consideration of blood ChEI as an
adverse effect has been and remains
controversial among the scientific
community. ChE may be significantly
inhibited in the blood without apparent
s:gns of impaired function, histological
damage or other clinical effects in
exposed individuals. There are
instances, though, where low levels of
ChEI are observed along with clinical
manifestations. A more detailed
discussion of the levels of ChEI for the
studies considered in the risk
assessment of aldicarb and its sulfoxide
is given in the January 30,1991 Notice.
The Agency agrees with the public
comments in that blood ChEI can be
considered as a biomarker of exposure.
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Federal Register / Vol. 56. No. 126 / Monday. July 1. 1991 / Rules and Regulations 3Q269
However, to be protective of public
health, the Agency considers that ChEI
can not be totally discounted in the risk
.•issessment for aldicarb. aldicarb
salfoxide. and aldicarb sulfone. The
Acency is currently evaluating the
cc-relation between ChEI and clinical
ri.sns of toxicity. If the conclusions of
this evaluation alter the basis presented
for the MCLG in this notice, then the
Agency will initiate a process for
determining whether the MCLG should
be revised. Thus, after consideration of
public comments, the Agency has
decided to base the final MCLG for
aldicarb. aldicarb sulfoxide. and
aidicnrb sulfone. on clinical signs. EPA
will continue to examine the relevance
of using ChEI in establishine an MCLG.
Over a period of time this effort is
expected to resolve the questions
related to the significance of ChEI.
Because the controversy has not yet
been fully resolved. EPA developed an
alternative approach for setting the
MCLG. using clinical signs.
Since both the Agency-verified RfD
and the alternative derivation of the
MCLC result in an MCLG value of 0.001
mg/1. the Agency is promulgating the
MCLG at this level. An MCLG of 0.001
mg/1 will be sufficiently protective of
public health.
The final MCLG of 0.001 mg/1 is based
on signs of clinical toxicity in dogs and
humans exposed to aldicarb. The
quantitative assessment stems from a
no-effect level for clinical effects of 0.02
rr.g/kg/day as determined in a 1-year
dog study (Hazclton Labs. Inc.. 1988). At
higher doses, effects such as diarrhea
and soft stools were observed. The
Agency has determined that these signs
are representative of clinical signs of
toxicity. In keeping with general Agency
practice (56 FR 3532), an uncertainty
factor of 100 was used to account for a
no-effect level from an animal study that
considers intra- and interspecies
differences in response to toxicity. The
resulting value, 0.0002 mg/kg/day. is
numerically the same as the RfD which
considers both clinical effects and ChEI.
This was adjusted by the assumption of
a 70 kg adult drinking an average of 2
liters water per day and a relative
sofirce contribution of 20% to yield an
MCLG of 0.001 mg/1.
Thejio-effect level of 0.02 mg/kg/day
and restating MCLG of 0.001 mg/1 is
supportedtjualitatively by a controlled
human study (Haines. 1971) and takes
into consideration the observation
reported in the Goldman.s.tudy (1990). In
the Haines study, no significant clinical
effects were observed in fouV-healthy
males given doses of 0.025 or 0.09 tng/"
kg/day. A higher dose of 0.1 mg/kg/day
resulted in neurological effects. The no-
effect level of 0.05 mg/kg/day was not
used as the sole basis for the MCLG
because of the limited scope of the study
such that a sensitive population may not
have been studied, and the narrow
range between the no-effect level and
the effect level. Moreover. Goldman el
al. reported clinical effects at estimated
doses lower than those reported by
Haines.
Goldman el al. reported clinical
effects in humans (including women and
children) following three separate
incidents involving aldicarb/aldicarb
sulfoxide in California. Exposure to
aldicarb sulfoxide from the
contaminated watermelons and
cucumbers were estimated to range from
0.002 to 0.08 mg/kg body weight. A low
effect level for clinical effects was
estimated at 0.002 mg/kg. This study is
not used as the sole basis for the MCLC.
however, since the authors noted that
the dosage calculations were uncertain
and because of the wide range of human
sensitivity demonstrated by these
individuals. The authors relied on self-
reports of food consumption, estimates
of weight consumed and estimates of
body weight
Although each of the studies has
limitations, as described above, the
Agency has determined that the dog and
human studies taken together support
the calculation of an MCLG of 0.001
mg/1.
In summary, the Agency is
promulgating an MCLG of 0.001 mg/1 for
aldicarb and aldicarb sulfoxide based
on a weight of evidence of clinical signs
of toxicity observed in humans and
animals.
Aldicarb sulfone.
The Agency reproposed an MCLG of
0.002 mg/L for aldicarb sulfone in the
January 30.1991 notice. This level was
based on a no-observed-adverse-effect
level for ChEI in blood of 0.1 mg/kg/day
and an uncertainty factor of 300.
Information on clinical effects in the
study was not reported.
Aldicarb sulfone is considered less
toxic than the parent based on a 25-fold
difference in acute toxicity: the LDso for
the sulfone is 25 mg/kg/day compared
to the LDso for aldicarb of 1 mg/kg/day .
No data are available to determine
clinical effects or chronic toxicity
associated with exposure to aldicarb
sulfone. As stated above, the Agency is
currently evaluating the correlation
between ChEI and clinical signs of
toxicity. Thus, the Agency will not use
the MCLG of 0.002 mg/L proposed for
the sulfone in the reproposal. Rather, to
be protective of public health, the
Agency is promulgating the MCLG of
0.001 mg/L established for aldicarb and
aldicarb sulfoxide. based on clinical
signs of toxicity as a surrogate for the
sulfone. If the conclusions of the Agency
evaluation of ChEI alter the basis for the
MCLG. then the Agency will initiate a
process for determining whether the
MCLG for aldicarb sulfone snould be
revised.
In summary, the Agency is
promulgating an MCLG of 0.001 mg/1 for
aldicarb sulfone.
2. Aldicarb. Aldicarb Sulfoxide. and
Aldicarb Sulfone MCLs
The proposed MCLs for aldicarb,
aldicarb sulfoxide, and aldicarb sulfone
were based upon an analysis of several
factors including: (1) The effectiveness
of the best available technology (BAT—
granular activated carbon) in removing
aldicarb, aldicarb sulfoxide. and
aldicarb sulfone to levels at or below
the proposed MCLs of 0.003 rr.g/1; (2) the
feasibility (including costs) of applying
BAT for large systems. EPA estimated
that the cost to remove aldicarb,
aldicarb sulfoxide and aldicarb sulfone
using GAC to be SlO-14 per household
and thus feasible: and (3) the
performance of analytical methods as
reflected in the practical quantification
level (PQL) for each contaminant. In the
proposed notice EPA stated that data
from Water Supply Studies showed that
the PQLs for aidicnrb. aldicarb
sulfoxide, and aldicarb sulfone could be
set at 0.003 mg/1 by broadening the
acceptance limits to ±55%.
The pivotal comments cor.cemcd
establishing the PQL for aldicarb.
aldicarb sulfoxide. and aldicarb sulfone.
One commenter noted that Water
Supply Studies *22-25 which were used
to calculate the PQL did not "bracket"
the proposed levels. This commenter
noted that the lowest levels in Water
Supply Studies *22-25 were 0.00947 mg/
1 for nldicarb. 0.008G7 mg/1 for aldicarb
sulfoxide. and 0.00833 mg/1 for aldicarb
sulfone. Several commentcrs objected to
EPA's adjustment of PQL acceptance
limits to achieve lower MCLs. These
oommenters noted that the usual Agency
practice is to use ± 20% or — 40% of the
true value. These commenters objected
to the Agency's broadening the
acceptance limits to ± 55"i arguing
instead that EPA should use a single
fixed acceptance limit.
After considering the comments. EPA
decided to revisit the rationale on which
the PQLs were based. As a result, the
Agency concluded that the elements of
the rationale that involved extrapolating
data were inappropriate for this
compound.
EPA set the proposed PQLs of 0.003
mg/1 by extrapolating from the loxvest
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30270 Federal Register / VoL 56. No. 126 / Monday; )uty 1. 1991 / Rules and Regulations
levels in Water Supply Studies 922-25
to the point at which 75 percent of the
participating laboratories would be able
to analyze within +55 percent of the
trae vahie. EPA used this extrapolation
technique because the Water Supply
Studies 722-25 study designs did not
include the levels of concern. Le.,
MCLGs of 0.001 and 0.002 mg/1 proposed
in the January 1991 Notice (56 FR 3606).
The existing Water Supply Studies
were designed to provide data for
assessment of laboratory performance
at levels of concern which were higher
(i.e.. MCLGs of Oj009 mg/1 proposed in
November 1985 (50 FR 46986) and OJH.
;-nd 0.04 mg/1 proposed in May 1989 (54
!R 22080)). la this case, the levels
( valuated in the Water Supply Studies
•. ere above the lexicological levels of
' oncera (0.001 mg/i) for aldicarb,
idicarb sulfoxide and aldicarb sulfone
.-. s proposed in January 1991. For this
i ;ason we decided to me an alternate
;. ocedure for setting the PQL for
; Idicarb. which set* the PQL at five
'..ines the interiaboratory method
election limit (IMDL). was first
ri iscussed in setting the MCL for vinyl
chloride (52 FR 25690. July 1967). This
procedure is used to set the PQL when
ihere is not water supply study data at
the level of concern or when the usual
proceedure would result in a PQL which
poses a greater than 10-4 cancer risk.
The aldicarb. aldicarb sulfoxide and
aldicarb sulfone PQLs were determined
using the range of 5 to 10 times the
IMDL The PQLs of 0.003.0.004 and 0.002
rng/1 for aldicarb, aldicarb sulfoxide and
.; Idicarb sulfone. respectively, are based
on the lower factor of 5 times the
respective LVlDLs (Le, 04005, 04008 and
0.0003 mg/i). EPA has previously stated
(i.e. EDB (56 FR 3526)) that the use of 5
times the IMDL instead of 10 times the
MDL to set the PQL may be appropriate
when other considerations suggest the
PQL should be lower (Le., where there is
.1 lack of performance evaluation data at
::: 3 lavel of concern for a particular
contaminant). In the case of aldicarb
and its metabolites, the Agency has
decided to base the PQL on 5 times the
IMDL because (a) it is feasible and (b) it
is closer to the MCLG than the 10
multiplier.
The validation study for Method 531.1
i .he approved method for the aidicarbs)
provides evidence that a PQL of 3J) mg/1
is achievable for aldicarb. The design
for this study is comparable to that of
the Water Supply Studies (Le-. unknown
concentrations, reagent grade water.
collaborative). The level of O003 mg/1
(3.24 ug/1, was analyzedTor aldicarb in
the study and resulted in gooiTplnecision
and accuracy with a mean recovery of
3.24 fig/1 and a standard deviation of
0.33 ug/L Results of analyses for
aldicarb sulfoxide and aldicarb sulfone
also had good precision and accuracy
but the levels analyzed were at levels of
6.40 and 6.44 ng/'l. respectively. EPA
believes that these method validation
results give additional support for the
PQLs.
EPA recognizes that, at the PQL levels
chosen, slightly less precision arid
accuracy will occur. However. EPA
believes that it is appropriate to accept
less precision in order to obtain more
stringent levels of cnntroL Because of
the lack of performance evaluation
studies at the MCLG, the acceptance
limits for aldicarb. aldicarb sulfoxide
and aldicarb sulfone will be based on
two standard deviations using Water
Supply Study statistics. EPA will
reevaiuate this when it acquires the
appropriate data at levels betow or at
the PQLs. from ongoing Water Supply
Study data to assess "fixed true value"
acceptance limits. EPA also believes
that the precision and accuracy at these
levels will improve after more use of the
relatively new methodology.
EPA has examined the health risks of
setting the MCLs above the MCLGs of
0.001 mg/L Children are the most
sensitive population for these
compounds. However, a child likely
would not consume a whole liter at one
time. More typically children consume
water throughout the day and this would
mitigate against adverse effects at the
MCLs and below. The adverse effects of
aldicarb are thought to be reversible
within 4 to 8 hours at higher levels of
exposure. Therefore, EPA believes that
the MCLs of 0.003 mg/1 for aldicarb.
0.004 mg/1 for aldicarb sulfoxide and
0.002 mg/1 for aldicarb mlfone are
protective for children. Until the
analytical chemistry and laboratory
performance improve. EPA believes the
MCLs for aldicarb. aldicarb sulfoxide.
and aldicarb sulfone are set at the
lowest level feasible. Consequently, for
the reasons cited above the MCL for
aldicarb. aldicarb sulfoxide and aldicarb
sulfone are established at 0.003 mg/1,
0.004 mg/1 and 0.002 mg/l. respectively.
C. Pentachlorophenol
1. Pentachlorophenol MCLG
On January 30.1991. EPA proposed an
MCLG of zero, based on a drinking
water contaminant classification of
Category 1 for pentachlorophenol (PCP).
This proposal was based on the
classification of PCP as a Class B2
carcinogen under EPA's cancer
classification system (Le, probable
human carcinogen). EPA. in reaching the
B2 classification, determined that there
is sufficient evidence of carciaogenicity
for pentachiorophenoi from animal
studies. This decision was supported by
the Science Advisory Board in April
1990. Two grades of pentachiorophenoi
(purified commercial and technical
grades) both induced multiple tumor
types at different dose levels in male
and female mice.
Summary of Comments
Three organizations submitted
comments on the Agency's carcinogen
classification for PCP. All three
commenters believe that the
carcinogenic evidence from animal
studies is limited. These commenters
argued that PCP should be classified in
Class € (with an MCLG of 0.2 mg/i).
based on a National Toxicology Program
bioassay which detected a response in
only one species of B6C3F1 mice. These
commenters cited other negative rodent
studies. One commenter calculated the
cancer risk and claimed that EPA- •
overestimated the cancer risk by a •
factor of 10. '
EPA's Response to the Comments
After careful review of the comments,
EPA reaffirmed that pentachlorophenol
should be classified as B2 carcinogen
(probable human carcinogen). The
studies cited by the commenters were
previously considered by the Agency
and no new information was provided
by the commenter.
EPA's B2 classification is based on
inadequate human data and sufficient
evidence of carcinoger.irity in animals:
statistically significant increases in the
incidences of multiple biologically
significant tumor types (hepatocellular
adenomas and carcinomas, adrenal
medulla pheochromocytomas and
malignant pheochromocytcrmas. and/or
hemangiosarcomas and hemangiomas)
in one or both sexes of B8C3F1 mice
using two different preparations of
pentachiorophenoi. In addition, a high
incidence of two uncommon tumors
(hemangiomas/hemangiosarcomas and
adrenal medulla pheochromocytomas)
was observed with both preparations.
This classification is supported by
mutagenicity data, which provide some
indication that PCP has clastogenic
potential.
Several studies in rodents cited by
commenters were unable to demonstrate
the carcinogenicity of PCP. However.
these studies were all judged by EPA to
be limited and not useful for drawing
conclusions concerning the
carcinogenicity of PCP. The study
reported by Innes et al (1969) used only
one dose with aa insufficient number of
animals. The study by Catilioa (1981)
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30271
•..sed an inappropriate route of
.idministration with only one dose, and
:here was excessive mortality. The
:udy bv Schwetz et al. (1978) used an
inadequate number of animals, and it is
no! clca;- wnether the maximum
;o!erated dose (.VITD) had been met.
Vinailv. the dose level, frequency and
.iuration of exposure were limited in the
•;:udy by Boutwell and Bosch (1959).
in quantifying the cancer risk. EPA
•.ised pooled tumor incidence of
hemangiosarcoma/hemangioma.
pheochromocytomas and liver neoplasm
in the female mice to obtain a slope
factor of 0.12 per (mg/kg) /day. This
slope factor results in a unit risk of 3 X
10"" per (Mg/1). This means an adult
person who drinks 2 liters of
contaminated water per day for life (70
vears.l, is expected to have an upper
hound cancer risk of 3 in a million at a
concentration of 1 jig/ 1 water. Thus, at
the proposed MCL of 1 pg/1. the upper
bound risk of cancer is within the 10"4 to
10"* range. The statement in the January
20 Federal Register (page 3608) that "A
cancer unit risk estimate of 4.76 C-08
cases/person (MS/1) /yr" should be
deleted.
EPA Conclusion
EPA reaffirms the Class B2
classification for pentachlorophenol and
nlaces pentachlorophenol in drinking
water contaminant Category I.
Consequently, the MCLG is set at zero.
2. Pentachlorophenol MCL
The proposed MCL for
pentachlorophenol was based upon an
analysis of several factors including: (1)
The effectiveness of the best available
technology, granular activated carbon.
in reducing influent concentrations to
the proposed MCL of 0.001 mg/1 or less:
(2) the feasibility (including costs) of
applying BAT for large systems at
approximately SlO per household per
yi'ar: (3) the performance of available
analytical methods as reflected in the
i'QL. Data from Water Supply Studies
=22-23 indicated that the PQL could be
established at 0.001 mg/1 with an
acceptance limit of - 50%: and (4)
coparison of the individual lifetime
*'cnrcinogenicriskof 3 X 10"6 for the
MCL to EPA's target risk range of 10~" to
\3~.*. EPA requested comment on
whejher the MCL should be established
;
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D. Barium
1. Barium MCLC
In May, 1989 EPA proposed an MCLG
of 5 mg/1 based upon the Wones et al.
(1987) human clinical study which failed
to detect adverse effects at 10.0 mg/1.
EPA applied an uncertainty factor of 2
to derive an MCLG of S mg/1
Subsequent to the May, 1939 proposal,
the Agency adopted an RfD of
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30273
In § l«.23:kj[5){ii}. ihe second nitrate
in the table with an acceptance limit of
=±15 percent. >0.4 ma/i id changed to
I'-.iirite ±: 15 percent >0.4ms/l.
* Revisions to § 141.23 Inorganic
Chemical Samniins and Analytical
Requirements inadvertently eliminated
inorcanic sampling and analytical
requi.-en-.unts for trie 9 inorganics listed
ia § 14l.il. EPA is reinsertir.g the
previous inorganic monitoring and
analytical requirements by adding
paragraphs (I) through (q) to § 141.23
(previously § 141.23 (a) through (e)). This
correction has the effect of retaining the
previous inorganic requirements for
cadmium, chromium, mercury, nitrate.
and selenium until July 30.1992: for
barium until January 1.1993; and beyond
July 30.1992 for arsenic.
Any alternate test procedures
previously approved under § 141.27 for
both inorganic and organic
contaminants continue to be effective
until July 30.1992 and January 1.1993.
for barium.
In § 141.24(e). Method 505 can also be
used to analyze for endrin and is added
to the list of acceptable methods.
In 5 141.24(h)(8) the sentence "After a
maximum of four quarterly samples
show the system is in compliance * * *"
is changed to read "After a minimum of
four quarterly samples show the system
is in compliance * * *" (emphasis
bdded). The reference to paragraph
(h)(12) is changed to (h)(ll).
In § 14l.24(h)(12)(iv) toxaphene is
added to the list of contaminants which
can be analyzed using EPA Method 508.
In § I4l.24(h)(13)(i) the reference to
paragraph (h)(13| is changed to
paragraph (h)(12).
The laboratory certification
requirement* for the pesticides were not
included In the final rule, in
§ 141.24(h)(19) EPA is including
laboratory certification requirements.
The performance requirements were
discussed and listed on pages 3550 to
3552 of the January 30.1991 Notice.
In § 141.62(b) the MCL for fluoride is
changed from 4 mg/1 to 4.0 mg/1.
In § 141.57(b) the reference to
§ 141.52(h) should be changed to
S Ufl.62(b).
In the footnotes to 9 143.4 (12) and (13)
the updated versions of the methods
should ft\ve been cited. In footnote 4.
EPA Method 200.7. version 3.1. April
1990 is changed to version 3.2. August
1990: In footnote 5. EPA Method 200.8.
version 4.1. March 1990. is changed to
version 4.3, August 1990: in footr.ote 6.
EPA Method 200.9. version 1.0. April
1990. is changed to version 1.1. August
1990.
In § 143.4(12) a later version oi the
method is cited. EPA changes Method I-
305i-64 to Method 1-3051-85.
In § 143.4(13) a later version of the
method is cited. EPA changes Method I-
3720-84 to 1-3720-85.
IV. Economk Analysis
Executive Order 12291 requires EPA
and other regulatory agencies to perform
u regulatory impact analysis (RIA) for
all "major" regulations, which are
defined as those regulations which
impose an annual cost to the economy
of $100 million or more, or meet other
criteria. The Agency has determined
that the proposed rule is a minor rule for
purposes of the Executive Order. This
regulation has been reviewed by the
Office of Management and Budget as
required by the Executive Order and
any comments they make will be
available in the public docket.
In accordance with the Executive
Order, the Agency previously conducted
an assessment of the benefits and costs
of regulatory alternatives as part of the
Phase II rule which was promulgated in
the January 30,1991 Federal Register.
This assessment in the Phase U rule
determined the impacts of this
regulation as part of the Phase II rule
and consequently these impacts are not
separately reconsidered in this notice.
A. Regulatory Impact
EPA's analysis conducted under the
proposed rule for 38 contaminants (54
PR 22062. May 22.1989) indicates that
approximately 378 systems would
violate the aldicarb MCL of 0.003 mg/1
based on the uncertainty in the data
base. EPA does not believe MCLs of
0.004 mg/1 for aldicarb sulfoxide and
0.002 mg/1 for aldicarb sulfone will
change this estimate. An additional 825
systems would violate the MCL for
pentachlorophenol.
One commenter provided information
disputing EPA's estimate of the 378
systems which would violate the MCLs
for aldicarb. cldicarb sulfoxide and
TABLE 1 .—REGULATORY IMPACT
aldicarb sulfone. This commenter noted
the relative lack of occurrence data to
estimate regulatory impact. This
commenter assumed l?i of ihe systems
(654 systems) would exceed the MCL for
aidicarb which is almost double the EPA
estimate. EPA acknowledges the
uncertainty in determining the
regulatory impact and stated in the
Proposed Notice that ±50% of its
estimate of 378 systems (189 to 567)
systems may violate the MCL. Though it
is conceivable that 654 systems may
violate the aldicarb MCL. EPA points
out that the recently completed National
Pesticide Survey did not detect aldicarb
in any well at levels exceeding 0X00071
mg/1.
Several commenters stated that EPA
should consider the impact of these
regulatory requirements on the
collateral effects which trickle down
through other regulatory programs such
as Superfund. the Clean Air Act (CAA).
stream water quality standards under
the Clean Water Act and requirements
under the Resource Conservation and
Recovery Act (RCRA). While EPA
acknowledges that these secondary
impacts may occur, the purpose of
today's action is solely to establish
drinking water standards that public
water systems must comply with.
Consequently, EPA does not consider
the cost of secondary impacts which
may occur under the CAA. Superfund, or
RCRA. One commenter also noted that
these secondary impacts also affect the
water supply industry by increasing the
waste and disposal costs of treatment
EPA is aware of this issue and did
include the cost of disposal in the
Regulatory Impact Analysis
accompanyiaf the January 30.1991 final
rule.
As stated earlier. EPA did not
reconsider the costs for the proposed
VOC monitoring requirements because
those costs were considered in the final
Phase II rule promulgated on January 30.
1991. The costs of today s VOC
monitoring requirements have virtually
no impact on the total cost of VOC
monitoring primarily because a single
analytical method can analyze a range
of contaminants. Sampling for all VOC
contaminants can be conducted at the
same time.
'>.
Aiaicam (including sutloiude and tulto
Pentacfttoroohenol ,
Contaminant
':* ^ '
nfl(
1
i
_ i
Systems in
violation
378
825
Annual •
ireatment r
cost 1
(SmiHion/yrl |
sa7|
S19
Typical HH ' treatment cost/systam/year
Small*
600
600
Medium * \
I
39)
39!
Large*
10-t«
to
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30274 Federal Register / Vol. 56. :No. 126 /Monday; July 1. 1991 / Rules and Regulations
TABLE 1.—REGULATORY IMPACT—Continued
Contaminant
; Annual i T/sical KH ' treatment cost/system/y<
Systems in i treatment
violation cost
(Smillion/yr) i
Medium
Large
0 I
Ol - $230-460 I ;S54-160I 5S26-110
| HH=household.
• Smail system serving 25-100 oeoole.
1 Medium system serving 10.000-25.000 peooie. For Banum medium system serves 3.3CO-10.000 people.
• Large systems serving more than 1,000.000 people.
1 Cost dependent upon BAT chosen.
We estimate that approximately
230.000 people will experience reduced
exposure to aldicarb, aldicarb sulfoxide
and aldicarb suifone. Approximately
060.000 people will have reduced
exposure to pentachlorophenol.
3. Regulatory Flexibility Analysis
The Regulatory Flexibility Act
requires EPA to consider the effect of
regulations on small entities. 5 U.S.C.
602 et sea. If there it a significant effect
on a substantial number of small
systems, the Agency must prepare a
Regulatory Flexibility Analysis which
describes significant alternatives which
would minimize the impact on small
entities. An analysis of the impact on
small systems due to the MCL for
aldicarb is included in the RIA which
supported the final Phase II rule
promulgated January 30,1991. The
Administrator has determined that the
proposed rule, if promulgated, will not
have a significant effect on a substantial
number of small entities.
C. Paperwork Reduction Act
The information collection
requirements in this rule have been
submitted for approval to the Office of
Management and Budget (OMB) under
the Paperwork Reduction Act. 44 U.S.C.
3501 et seq as part of the information
collection requirements supporting the
final Phase II rule on January 30,1991.
The information collection requirements
are not effective until OMB approves
them and a technical amendment to that
effect is published in the Federal
Register.
List of Subjects in 40 CFR Parts 141,142,
and 143
Chemicals, Reporting and
-recordkeeping requirements. Water
supply. Administrative practice and
procedure.
Dated: ,une 17.1991.
William K. Reilly.
. \-Jmimstrator. Environmental Protection
Agency. -*
For the reasons set forthf«rthe
preamble, title 40 of the Code of Federal
Regulations is amended as follows:
PART 141—NATIONAL PRIMARY
DRINKING WATER REGULATIONS
1. The authority citation for part 141
continues to read as follows:
Authority: 42 U.S.C. 300f. 3COg-l. 300g-2.
3000-3. 300g-4. 300g-5. 300g-6. 300j-4 and
300 j-9.
2. In § 141.6. paragraph (a) is revised
and paragraph (g) is added to read as
follows:
§141.6 Effective date*.
(a) Except as provided in paragraphs
(b) through (g) of this section, the
regulations set forth in this part shall
take effect on June 24.1977.
• • » • •
(g) The regulations contained in
Section 141.6. paragraph (c) of the table
in 141.12. and 141.62(b)(l) are effective
July 1,1991. The regulations contained in
§§ I41.ll(b), 141.23,141.24.142.57(b).
143.4(b)(12) and (b)(13), are effective
July 30,1992. The regulations contained
in the revisions to §§ I41.32(e)(16), (25)
through (27) and (46): 141.50(a)(15).
(b)(4). (b)(5) and (b)(6); 141.51(b)(3);
141.61(c)(2). (c)(3). (c)(4) and (c)(16);
141.62(b)(3) are effective January 1.1993.
3. Section 141.11 is amended by
revising the introductory text of
paragraph (b) to read as follows:
§ 141.11 Maximum contaminant levels for
Inorganic chemicals.
• • * * *
(b) The Maximum contaminant levels
for cadmium, chromium, mercury,
nitrate end selenium shall remain
effective until July 30.1992; the
maximum contaminant level for lead
shall remain effective until December 7,
1992: the maximum contaminant level
for barium shall remain effective until
January 1,1993.
*****
4. In § 141.12. paragraph (c) in the
table is revised to read as follows:
§ 141.12 Maximum contaminant levels for
organic chemicals.
Level
milli-
, grams
' per liter
(c) Total triha!omethanes (the sum of the I
concentrations of bromodichtorometh- i
ano, dibromocfiloromethane. trbromo- I
methane (bromoform) and tnchloro- |
methana (Chloroform)) j 0.10
5. Section 141.23 which was published
January 30,1991 (55 FR 3526) and which
will become effective July 30.1992. is
amended by revising paragraphs (a)(4)(i)
(excluding the table) and (i)(l): revising
the table in (k)(l); revising paragraph
(k)(2); revising the table in (k)(4);
revising the table in (k)(5)(ii); and
adding paragraphs (1). (m). (n). (o), (p).
and (q) to read as follows:
§ 141.23 Inorganic chemical sampling and
analytical requirements.
* * * * «
(a) * ' '
(4)' ' '
(i) If the concentration in the
composite sample is greater than or
equal to the detection limit of any
inorganic chemical, then a follow-up
sample must be analyzed within 14 days
from each sampling point included in the
composite. These samples must be
analyzed for ihe contaminants which
were detected in the composite sample.
Detection limits for each analytical
method are the following:
(1) For systems which are conducting
monitoring at a frequency greater than
annual, compliance with the maximum
contaminant levels for asbestos, barium.
cadmium, chromium, flouride. mercury.
and selenium is determined by a running
annual average at each sampling point.
If the averaae at any sampling point is
greater than the MCL. then the system is
out of compliance. If any one sample
would cause the annual average to be
exceeded, then the system is out of
compliance immediately. Any sample
below the method detection limit shall _
-------
Fedatai Hflgtgto / Voi 56.' No. 126 / M&a«i*.y. July 1. 1991
Jtega
foe calculated at zero for the purpose of
determining the annual average.
*****
jk) Inorganic analysis:
(1)
INORGANIC CONTAMINANTS ANALYTICAL METHODS
— ,^-
AStWStOfr 1J...
Cad™*"1*
C*™™<"
MgfCyry ,
Nitrate
Selenium
Traiwrescton Etoctron Microscopy
AtowiiM* *|i«MMii*bM» ftitiw* MniVfltVM
frttfrftarVB.y oonrtod p 20&3,
or Method « D2972-88& or Method -
' "Methods of Chemical Anarysit of Water and
Wastes." EPA Environmenul Monitoring and
Support Laboratory. Clnemnan. Ohio 45266 (HPA-
«B/4-79-a8». Match 1070. Available ton ORD
PttbtteXtaB*, CEU. EPA. Clacnmatt. Ohio 46268. For
sppiend anarjrtlcai procation* lor netalt. the
tmtajMs applicable to totel meul* must be used.
» "Steadard Method* for the Examination ol
Witar and Wsstawattr." 16th Edition. Amencan
307A. or Method »1-1062-85. Atomic
Absorption—Gaseous Hydride; or
Method • 206.4. or Method * D-2972-
88A. or Method * 307B,
Spectrophotometric, Silver Oiethyl-
PubUc Health A»»oc«lloo. American Water Works
Ajuociation. Water Pollntion Control Federation.
'.90S.
3 Technique* of Water-Resources Investigation of
the United States Geological Survey. Chapter A-l,
"Methods for Detemrtantlon of Inorganic
Subatancea In Water and Fluvial Sedimen;a.~ Book
i. 1979. Stock £014-001-03177-9. Available from
dithiocarbamate; or Method 200.7A.
Inductively Coupled Plasma
Technique *.
Superintendent of Documents. U.S. Government
Printing Office. Washington. DC 20402.
• Annual Book of ASTM Standards, part 31
Water. American Society for Testing and Materials.
1316 Race Street. Philadelphia. Pennsylvania 1B103.
8 Appendix to Method 200.7. March 1987.133.
EPA. Environmental Monitoring Systems
Laboratory. Cincinnati. OH 45383.
'.Contaminant
Asbestos.. .
Barium' _
Cadmium'
Chromium •_
Fluoride '..
Mercury ' ...
Nitrate:
1 Chtorlnm
rton-chto
liilraa
1
Jrv>m *-r
...
iV
.., , , ;^...
Hf
'1nfte4
ConHOj topH <2
ConHOi to pH <2
Coo HO, iopH <2._
i^onHOi InpH s?
Cart 4*C
fVmtVJO, Inpw ^2 I
nsmi m-
Container '
PorG .
p or G _ _ _,
PorG
PorG .- _i
Pflrfl, H
P0r(i
pnrn
p/irO
PnrO
Tune1
6 months.
6 months'
6 months.
1 monO).
28 days.
28 days.
14 days. - . --
4S hours.
-------
30276
Federal Register / Vol. 56, No. 126 / Monday, July 1. 1991 / Rules and Regulations
Contaminant
Preservative
Container *
Time4
Selenium ' Con UNO, to pH <2 .
; P or G I 5 momns.
' 'I HNO] cannot be used because of sloping restrictions, sample mav be initially preserved by icing and immediately shioping it to the laboratory. Upon rec
n the laboratory, trie sample must be acidified with con HOj to pH <2. At time of analysis, sample container snouid be thoroughly nnsed with 1:1 HNCv washings
snould be added to samoie.
- = = elastic, nard or son: G = glajs. hard or sett.
11n all cases, samples snould oe analyzed as soon after collection as possible.
15)
Contaminant
Acceptance limit
Asbestos [ 2 standard deviations
based on study
! statistics
Earium =15% at >0.15mg/l
Cadmium =20% at > 0.002 mg/l
Chromium ±15% at >001 mq/l
cluonde =10% at 1 to 10 mg/l
Mercury =30% at > 0.0005 mg/l
Nitrate =10% at >0.4mg/i "
Nitrite =15% at > 0.4 mg/l
cv.lemum ; =20% at 2 0.01 mg/l
(I) Analyses for the purpose of
determining compliance with § 141.11
shall be conducted using the
requirements specified in paragraphs (i)
through (q) of this section.
(1) Analyses for all community water
systems utilizing surface water sources
..nail be completed by June 24.1978.
7 -ese analyses shall be repeated at
yearly intervals.
i ?.} Analyses for all community water
systems utilizing only ground water
sources siiail be completed by June 24.
7T3. These analyses shall be repeated
.! three-year intervals.
(3) For non-community water systems.
whether supplied by surface or ground
sources, analyses for nitrate shall be
comoleted by December 24.1980. These
.ir,:iiy:;es ?i:aii be repeated at intervals
ii:Merminea by th« State.
(4) The Statj has the authority to
lirt'ermine compliance or ir.ilidte
t.ni.;rcr:mcnt action based upon
maiyticai results and other information
compiled by their sanctioned
representatives and agencies.
(m) If the result of an analysis made
under paragraph (!) of this section
indicates that the level of any
•Mntamir.-int listed in 5141.11 exceeds
»tie maximum contaminant level, the
sifpplier of ths water shall report to thj
State within 7 ilays and initiate three
Additional analyses at the sarns
sampling point within one month.
(••>) Whs:: t.is average of four analyses
:v.ads pursu;ir.t to paragraph (m) of this
.-ectisjn. rounded to the same number of
significant figures as the maximum
contaminant level for the substance in
question, exceeds the maximum
contaminant level, the supplier of water
shall notify the State pursuant to
§ 141.31 and give notice to the public
pursuant to § 141.32. Monitoring after
public notification shall be at a
frequency designated by the State and
shall continue until the maximum
contaminant level has not been
exceeded in two successive samples or
until a monitoring schedule as a
rendition to a variance, exemption or
enforcement action shall become
effective.
(o) The provisions of paragraphs (m)
and (n) of this section notwithstanding,
compliance with the maximum
contaminant level for nitrate shall be
determined on the basis of the mean of
two analyses. When a level exceeding
the maximum contaminant level for
nitrate is found, a second analysis shall
be initiated within 24 hours, and if the
mean of the two analyses exceeds the
maximum contaminant level, the
supplier of wster shall report his
findings to the State pursuant to £ 141.31
and shall notify the public pursuant to
§ 141.32.
(p) For the initial analyses required by
paragraph (I) (1). (2) or (3) of this
section, data for surface waters
acquired within one year prior to the
effective date and data for ground
waters acquired within 3 years prior to
the effective date of this part may be
substituted at the discretion of the State.
(q) Analyses conducted to determine
compliance with § 141.11 shall be made
in accordance with the following
methods, or their equivalent as
determined by the Administrator.
(1) Arsenic-Method ' 20U.2, Atomic
Absorption Furnace Technique: or
Nfethod ' 208.3, or Method * D2!)72-ea3
1 "M,.-!rioC3 of Chemical Analysis c/ Wntr.r ;•:...:
Wnsfss." EPA Fnvircnmental Monitoring and
Support Laboratory. Cincinnati. Ohio 46268 IF.PA-
iiW),'4-79-020l. March 1983. Available from URD
PbDiications. CES1. EPA. Cincinn.'iti. Ohio 452M. For
tpproved analytical procedures for rni'iaia. tha
!»i:hnique applicable to total metals must he unm.
•' "S!Hnrl?,rd Methods for th? ExaniinHti-in pi
V.'jter a:ni VVastewater." 16:h EJiiion. Amrrit an
Public Health Association. A.^inncan IVdter Works
A*snriiii!un. Waler Pollution Control r'ed>:r;ition.
or Method 2 307A. or Method 3 1-1062-
85, Atomic Absorption—Gaseous
Hydride: or Method l 208.4. or Method *
D-2972-88A. or Method a 307B,
Spectrophotometric, Silver
Diethyldithiocarbamate: or Method •
200.7, Inductively Coupled Plasma
Technique.
(2) Barium-Method ' 208.1 or Method *
308, Atomic Absorption—Direct
Aspiration: or Method ' 208.2, Atomic
Absorption Furnace Technique: or
Method 8 200.7, Inductively Coupled
Plasma Technique.
(3) Cadmium-Method > 213.1 or
Method 4 D 3557-78A or B. or Method a
310A. Atomic Absorption—Direct
Aspiration: or Method ' 213.2 Atomic
Absorption Furnace Technique: or
Method • 200.7. Inductively Couplcdd
Plasma Technique.
(4) Chromium-Method * 218.1 or
Method 4 D1537-77D. or Method * 312A.
Atomic Absorption—Direct Aspiration:
or Chromium-Method ' "13.2 Atomic
Absorption Furnace Technique: or
Method 8 2C0.7. Inductively Couple
Plasma Technique.
(5) Mercury-Method ' 245.1. or
Method * D-3223-69. or Method * 320A,
Manual Cold Vapor Technique: or
Method > 245.2. Automated Cold Vapor
Technique.
(6) Nitrate-Method ' 352.1. or
Method « D-992-71. or Method * 353.3,
or Method 4 D-3367-79B. or Method *
418-C. Spectrometric. Cadmium
Reduction: Method > 333.1, Automated
Hydrazine Reduction: or Method ' 353.2.
or Method 4 D-.in67-rDA, or Method *
4I3F, Automaied Cadmium Reduction.
1 Techniques of Water-Resources Investigation of
;hr Ur.itpd States Geological Survey. Chapter A-l.
-".!:>lhoris for Determination of Inoreenic
Substances in Water and Fluvial Sediments." Book
S. 1979. Slock -0114-001-03177-8. Available from
S:'.prnntendcnt of Documents. U.S. Government
i'r-rmng (Jtfice. vV^shm^ton. DC 20402.
• Annual Book of ASTM Standards -rt 31
W.-.ter. Arnerican Society for Testing . j Materials.
\\l~* Race Street. FhiUdeiDnia. Pennsy..ania 15103.
1 '!Reservefl|.
* "Inductively Coupled Plasmj-Alomic Emission
Spnctrorr.utric Method for T.-^cc Elemont Analysis
.1 W^icr ar.J Wti-.ta—Method 200.7" wi:h
Appendix to Method 200.7 entitled. "Inductively
(,'juplrri Plasma-Atomic Emission Analysis of
DrinkinR Water." March 1937. Available from EPA's
Environmental Monilonng and Support Laboratory.
Cincinnati. Ohio 452G8.
-------
Federal Register. / V0L 56, No. 126 / Monday. Jyly l.< 1991 ARules.gnd. Regulations
30587
(7) Selenium-Method > 270.2. Atomic
Absorption Furnace Technique: or
Method l 270.3: or Method 3 1-1667-85.
pr Method « D-3059-79, or Method *
603F, Hydride Generation—Atomic
Absorption Spectrophotometry.
(8) Lead-Method l 239.1 or Method *
D3559-78A or B. or Method » 301-A II or
III. pp. 148-152. Atomic Absorption-
Direct Aspiration: or Method l 239.2.
Atomic Absorption Furnace Technique:
or Method 8 200.7, Inductively Coupled
Plasma Technique.
6. In § 141.24. which was published
January 30.1991 (56 FR 3526) and which
will become effective July 30.1992.
paragraphs (e) and (f) are revised:
paragraphs (h)(8). (h)(12) (iv), (vi). (vii).
ar.d (h)(13)(i) are revised: and paragraph
(h)(19) is added to read as set forth
below. In addition, paragraph (g), which
was not affected by the Jan. 30.1991
amendment, is amended by revising
paragraph (g) introductory text and
adding (g)[8) to become effective July 30,
1992.
§141.24 Organic chemical* other than
total trihalomethanes, sampling and
analytical requirements.
• • • • •
(e) Analysis made to determine
compliance with the maximum
contaminant level for endrin in
§ 141.12(a) shall be made in accordance
|With EPA Methods 505. "Analysis of
Organohalide Pestcides and Commercial
Polychlorinated Biphenyl Products
(Aroclors) in Water by Microextraction
and Gas Chromatography" and 508,
"Determination of Chlorinated
Pesticides in Water by Gas
Chromatography With an Electron
Capture Detector." The Methods are
contained in "Methods for the
Determination of Organic Compounds in
Drinking Water." ORD Publications.
CERI. EPA/600/4-88/039. December
1988. These methods are available from
the National Technical Information
Service (NTIS), U.S. Department of
Commerce. 5285 Port Royal Road.
Springfield. VA 22161. The toll-free
number is 1-800-336-4700.
(f) Beginning on January 1,1993.
analysis of the contaminants listed in
§ rai.61(a) (1) through (18) for the
purpose of determining compliance with
the maximum contaminant level shall be
conducte&as follows:
(1) Ground water systems shall take a
minimum of one sample at every entry
point to the distribution system which is
representative of each well after
treatment (hereafter called7a sampling
point). Each sample must be taken at the
same sampling point unless condiftohs
make another sampling point more
representative of each source, treatment
plant, or within the distribution system.
(Z) Surface water systems (or
combined surface/ground) shall take a
minimum of one sample at points in the
distribution system that are
representative of each source or at each
entry point to the distribution system
after treatment (hereafter called a
sampling point). Each sample must be
taken at the same sampling point unless
conditions make another sampling point
more representative of each source,
treatment plant, or within the
distribution system.
(3) If the system draws water from
more than one source and the sources
are combined before distribution, the
system must sample at an entry point to
the distribution system during periods of
normal operating conditions (i.e.. when
water representative of all sources is
being used).
(4) Each community and non-transient
non-community water system shall take
four consecutive quarterly samples for
each contaminant listed in S 141.61(a)
(2) through (18) during each compliance
period, beginning in the compliance
period starting January 1,1993.
(5) If the initial monitoring for
contaminants listed in 8 141.61(a) (l)
through (8) and the monitoring for the
contaminants listed in { 141.61(a) (9)
through (18) as allowed in paragraph
(f)(18) has been completed by December
31.1992. and the system did not detect
any contaminant listed in S 141.61(a) (1)
through (18), then each ground and
surface water system shall take one
sample annually beginning January 1.
1993.
(6) After a minimum of three years of
annual sampling, the State may allow
groundwater systems with no previous
detection of any contaiminant listed in
9 141.Bl(a) to take one sample during
each compliance period.
(7) Each community and non-transient
groundwater system which does not
detect a contaminant listed in
S 141.61(a) (1) through (18) may apply to
the State for a waiver from the
requirements of paragraphs (f)(5) and
(f)(8) of this section after completing the
initial monitoring. (For the purposes of
this section, detection is defined as
> 0.0005 mg/L) A waiver shall be
effective for no more than six years (two
compliance periods).
(8) A State may grant a waiver after
evaluating the following factors):
(i) Knowledge of previous use
(including transport storage, or
disposal) of the contaminant within the
watershed or zone of influence of the
system. If a determination by the State
reveals no previous use of the
contaminant within the watershed or
zone of influence, a waiver may be
granted.
(ii) If previous use of the contaminant
is unknown or it has been used
previously, then the following factors
shall be used to determine whether a
waiver is granted.
(A) Previous analytical results.
(B) The proximity of the system to a
potential point or non-point source of
contamination. Point sources include
spills and leaks of chemicals at or near a
water treatment facility or at
manufacturing, distribution, or storage
facilities, or from hazardous and
municipal waste landfills and other
waste handling or treatment facilities.
(C) The environmental persistence
and transport of the contaminants.
(D) The number of persons served by
the public water system and the
proximity of a smaller system to a larger
system.
(E) How well the water source is
protected against contamination, such
as whether it is a surface or
groundwater system. Groundwater
systems must consider factors such as
depth of the well the type of soil, and
wellhead protection. Surface water
systems must consider watershed
protection.
(9] As a condition of the waiver a
groundwater system must take one
sample at each sampling point during
the time the waiver is effective (i.e., one
sample during two compliance periods
or six years) and update its vulnerability
assessment considering the factors
listed in paragraph (f)(8) of this section.
Based on this vulnerability assessment
the State must reconfirm that the system
is non-vulnerable. If the State does not
make this reconfirmation within three
years of the initial determination, then
the waiver is invalidated and the system
is required to sample annually as
specified in paragraph (5) of this section.
(10) Each community and non-
transient surface water system which
does not detect a contaminant listed in
§ 141.61(a) (1) through (18) may apply to
the State for a waiver from the
requirements of (f)(5) of this section
after completing the initial monitoring.
Systems meeting this criteria must be
determined by the State to be non-
vulnerable based on a vulnerability
assessment during each compliance
period. Each system receiving a waiver
shall sample at the frequency specified
by the State (if any).
(11) If a contaminant listed in
§ 141.61(a) (2) through (18) is detected at
a level exceeding 0.0005 mg/1 in any
sample, then:
-------
30278 Federal Register / Vol. 56. No. 126 / Monday. July 1. 1991 / Rules and Regulations
(i) The system must monitor quarterly
it each sampling point which resulted in
; detection.
(ii) The State may decrease the
quarterly monitoring requirement
specified in paragraph (f)(ll)(i) of this
section provided it has determined that
;ie system is reliably and consistently
:elow the maximum contaminant level.
in no case shall the State make this
Determination unless a groundwater
system takes a minimum of two
quarterly samples and a surface water
system takes a minimum of four
quarterly samples.
(iii) If the State determines that the
system is reliably and consistently
beiow the MCL, the State may allow the
:ys;em to monitor annually. Systems
which monitor annually must monitor
curing the quarterfs) which previously
;. i elded the highest analytical result
[ivj Systems which have three
consecutive annual samples with no
detection of a contaminant may apply to
.-e State for a waiver 85 specified in
^aragraph (f)(7) of this section.
(v) Groundwater systems which have
detected one or more of the following
• .vo-carbon organic compounds:
[iichloroethylene, tetrachloroeihylene.
i 2-dichloroethane, 1.1.1-trichloroethane,
:s-1.2-dichloroethylene, trans-1.2-
:::chloroethylene, or 1.1-
i^chloroethylene shall monitor quarterly
:or vinyl chloride. A vinyl chloride
:ample snail be taken at each sampling
•joint at which one or more of the two-
carbon organic compounds was
.elected, if the results of the first
Analysis do not detect vinyl chloride, the
state may reduce the quarterly
monitoring frequency of vinyl chloride
monitoring to one sample during each
compliance period. Surface water
systems are required to monitor for
vinyl chloride as specified by the State.
[12] Systems which violate the
requirements of { 141.81(a) (1) tlirough
'• 13), as determined by paragraph (f)U5)
of this section, must monitor quarterly.
After a minimum of four consecutive
<.i:arterly samples which show the
system is in compliance as specified in
paragraph (.1(15) of this section the
system and the State determines that
•he system is reliably and consistently
below the maximum contaminant level.
:he system may monitor at the
frequency and rime specified in
paragraph (f)(ll)(iin of this section.
! 13) The State may require a
confirmation sample for positive or
negative results. If a confirmation
• ample is required by. the State, the
result must be averaged with the first
sampling result and the average is used
for the compliance determination as
specified by paragraph (0(15). States
have discretion to delete results of
obvious sampling errors from this
calculation.
(14) The State may reduce the total
number of samples a system must
analyze by allowing the use of
compositing. Composite samples from a
maximum of five sampling points are
allowed. Compositing of samples must
be done in the laboratory and analyzed
within 14 days of sample collection.
(i) If the concentration in the
composite sample is > 0.0005 mg/1 for
any contaminant listed in 9 141.61(a),
then a follow-up sample must be taken
and analyzed within 14 days from each
sampling point included in the
composite.
(ii) If duplicates of the original sample
taken from each sampling point used in
the composite are available, the system
may use these instead of resampling.
The duplicate must be analyzed and the
results reported to the State within 14
days of collection.
(iii) Compositing may only be
permitted by the State at sampling
points within a single system, unless the
population served by the system is
> 3,300 persons. In systems serving
> 3.3CO persons, the State may permit
compositing among different systems
provided the 5-sample limit is
maintained.
(iv) Compositing samples prior to CC
analysis.
(A) Add 5 ml or equal larger amounts
of each sample (up to 5 samples are
allowed) to a 25 ml glass syringe.
Special precautions must be made to
maintain zero headspace in the syringe.
(B) The samples must be cooled at 4'C
during this step to minimize
volatilization losses.
(C) Mix well and draw out a 5-ml
aliquot for analysis.
(D) Follow sample introduction,
purging, and desorption steps described
in the method.
(E) If less than five samples are used
for compositing, a proportionately small
syringe may be used.
(v) Compositing samples prior to CC/
MS analysis.
(A) Inject 5-ml or equal larger
amounts of each aqueous sample (up to
5 samples are allowed) into a 25-ml
purging device using the sample
introduction technique described in the
method.
(B) The total volume of the sample in
the purging device must be 25 ml.
(C) Purge and desorb as described in
the method.
(IS) Compliance with $ 141.Bl(a) (1)
through (18) shall be determined based
on the analytical results obtained at
each sampling point
(i) For systems which are conducting
monitoring at a frequency greater thaa
annual, compliance is determined by a
running annual average of arl samples
taken at each sampling point If the
annual average of any sampling point is
greater than the MCL. then the system is
out of compliance. If the initial sample
or a subsequent sample would cause the
annual average to be exceeded, then the
system is out of compliance
immediately.
(ii) If monitoring is conducted
annually, or less frequently, the system
is out of compliance if the level of a
contaminant at any sampling point is
greater than the MCL. If a confirmation
sample is required by the State, the
determination of compliance will be
bused on the average of two samples.
(iii) If a public water system has a
distribution system separable from other
parts of the distribution system with no
interconnections, the State may allow
the system to give public notice to only
that area served by that portion of the
system which is out of compliance.
(16) Analysis for the contaminants
listed in § 141.61 (a) (1) through (18) shall
be conducted using the following EPA
methods or their equivalent as approved
by EPA. These methods are contained in
Methods for the Determination of
Organic Compounds in Drinking Water.
ORD Publications. CERI. EPA/600/4-63/
039. December 1968. These documents
are available from the National
Technical Information Service (NTIS).
U.S. Department of Commerce, 5285 Port
Royal Road. Springfield, Virginia 22101.
The toll-free number is 800-338-J7CO.
(i) Method 502.1. "Volatile
Halogenated Organic Chemicals in
Water by Purge and Trap Gas -
Chroma tography."
(ii) Method 502.2. "Volatile Organic
Compounds in Water by Purge and Trap
Capillary Column Gas Chromatography
with Photoionization and Electrolytic
Conductivity Detectors in Series."
(iii) Method 503.1, "Volatile Aromatic
and Unsaturated Organic Compounds in
Water by Purge and Trap Gas
Chromatography."
(iv) Method 524.1. "Measurement of
Purgeable Organic Compounds in Water
by Purged Column Gas
Chromatography/Mass Spectrometry."
(v) Method 524.2. "Measurement of
Purgeable Organic Compounds in Water
by Capillary Column Gas
Chromatography/Mass Spectrometry."
(17) Analysis under this section shall
only be conducted by laboratories that
are certified by EPA or the State
according to the following conditions:
(i) To receive certification to conduct
analyses for the contaminants in
-------
Federal-Register / Vol. 56, No. 126 / T^bnday, July 1'1991 /Rules arid'Regulations 30279
§ 141.61(a) (2) through (18) the
laboratory must:
. (A) Analyze Performance Evaluation
samples which include these substances
provided by EPA Environmental
Monitoring and Support Laboratory or
equivalent samples provided by the
State.
(B) Achieve the quantitative
acceptance limits under paragraphs
(f)(17(i) (C) and (D) of this section for at
least 80 percent of the regulated organic
chemicals listed in § 141.61(a) (2)
through (IB).
(C) Achieve quantitative results on
the analyses performed under paragraph
(f)(17)(i)(A) of this section that are
within ±20 percent of the actual amount
of the substances in the Performance
Evaluation sample when the actual
amount is greater than or equal to 0.010
mg/1.
(D) Achieve quantitative results on
the analyses performed under paragraph
(f)(17)(i)(A) of this section that are
within ±40 percent of the actual amount
of the substances in the Performance
Evaluation sample when the actual
amount is less than 0.010 mg/1.
(E) Achieve a method detection limit
of 0.0005 mg/1, according to the
procedures in appendix B of part 136.
(ii) To receive certification for vinyl
chloride, the laboratory must:
(A) Analyze Performance Evaluation
samples provided by EPA
Environmental Monitoring and Support
Laboratory or equivalent samples
provided by the State.
(B) Achieve quantitative results on the
analyses performed under paragraph
(f)(17)(ii)(A) of this section that are
within ±40 percent of the actual amount
of vinyl chloride in the Performance
Evaluation sample.
(C) Achieve a method detection limit
of 0.0005 mg/1. according to the
procedures in appendix B of part 136.
(D) Obtain certification for the
contaminants listed in § 141.Cl(a) (2)
through (18).
(18) States may allow the use of
monitoring data collected after January
1.1988. required under section 1445 of
the Act for purposes of initial monitoring
compliance. If the data are generally
consistent with the other requirements
in this section, the State may use these
data (i.e^a single sample rather than
four quarterly samples) to satisfy the
initial monitoring requirement of
paragraph (f)(4) of this section. Systems
which use grandfathered samples and
did not detect any contamtnant listed in
§ 141.61(a) (1) through (18) shtll begin-
monitoring annually in accordance^vith
paragraph (f)(5) of this section beginning
[anuary 1,1993.
(19) States may increase required
monitoring where necessary to detect
variations within the system.
(20) Each approved laboratory must
determine the method detection limit
(MDL). as defined in appendix B to part
136. at which it is capable of detecting
VOCs. The acceptable MDL is 0.0005
mg/1. This concentration is the detection
concentration for purposes of this
section.
(21) Each public water system shall
monitor at the time designated by the
State within each compliance period.
(g) For systems in operation before
January 1,1993. for purposes of initial
monitoring, analysis of the contaminants
listed in 5 141.61(a) (1) through (8) for
purposes of determining compliance
with the maximum contaminant levels
shall be conducted as follows:
• • • • •
(8) Until January 1.1993. the State
may reduce the monitoring frequency in
paragraphs (g)(l) and (g)(2) of this
section, as explained in this paragraph.
• * • • •
(h) • * •
(8) Systems which violate the
requirements of § 141.61(c) as
determined by paragraph (h)(ll) of this
section must monitor quarterly. After a
minimum of four quarterly samples
show the system is in compliance and
the State determines the system is
reliably and consistently below the
MCL. as specified in paragraph (h)(ll) of
this section, the system shall monitor at
the frequency specified in paragraph
(h)(7)(iii) of this section.
• « » • •
(12) ' ' •
(iv) Method 508. -Determination of
Chlorinated Pesticide* in Water by Gas
Chromatography with an Electron
Capture Detector." Method 508 can be
used to measure chlordane. heptachlor.
heptachlor epoxide. lindane.
methoxychlor and toxaphene. Method
508 can be used as a screen for PCBs.
• • • • •
(vi) Method 515.1. Revision 5.0.
"Determination of Chlorinated Acids in
Water by Gas Chromatography with an
Electron Capture Detector" as revised
May 1991. Method 515.1 can be used to
measure 2,4-D, 2.4.5-TP (Silvex) and
pentachlorophenol.
(vii) Method 525.1. Revision 3.0
"Determination of Organic Compounds
in Drinking Water by Liquid-Solid
Extraction and Capillary Column Gas
Chromatography/Mass Spectrometry"
as revised May 1991. Method 525.1 can
be used to measure alachlor, atrazine.
chlordane. heptachlor. heptachlor
epoxide. lindane. methoxychlor. and
pentachlorophenoL
(13) ' • '
(i) Each system which monitors for
PCBs shall analyze each sample using
either Method 505 or Method 508 (see
paragraph (h)(12) of this section).
*•**•*
(19) Anaylsis under this section shall
only be conducted by laboratories that
have received certification by EPA or
the State and have met the following
conditions:
(i) To receive certification to conduct
analyses for the contaminants in
§ 141.61(c) the laboratory must:
(A) Analyze Performance Evaluation
samples which include those substances
provided by EPA Environmental
Monitoring and Support Laboratory or
equivalent samples provided by the
State.
(B) Achieve quantitative results on the
analyses that are within the following
acceptance limits:
Contaminant
OBCP
EDS
Alachlor
Atrazino . .. -
Carbofuran «-. ............
CtiJocdanA *•
Heptacfflor Epoxide
Undane
Methoxychtor
PC89(aa
Oacachtorobiphenyl).
Toxaphene
Aldicarto
Aldicaio sutfoxjde....
AWicaro sutfone
Pentacnloropnenol
2,4-D _ _
2.J.TD
(percent)
± 40
± 40.
± 45.
± 45.
± 45.
± 45.
•*• 45
± 45.
± 45.
* 45.
0-200.
±45.
2 standard deviations.
2 standard deviations.
2 standard deviations.
±50.
± 50.
* 50.
(ii) [Reserved]
7. In § 141.32. paragraphs (e)(16). (25)
through (27), and (46) are added to read
as follows:
§ 141.32 Public notification.
* * * * •
M • • •
(16) Barium. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that barium is a health
concern at certain levels of exposure.
This inorganic chemical occurs naturally
in some aquifers that serve as sources of
ground water. It is also used in oil and
gas drilling muds, automotive paints.
bricks, tiles and jet fuels. It generally
gets into drinking water after dissolving
from naturally occurring minerals in the
ground. This chemical may damage the
heart and cardiovascular system, and is
associated with high blood pressure in
laboratory animals such at rats exposed
-------
30280 Federal Register / Vol. 56. No. 128 / Monday. July 1. 1991 / Rules and Regulations
to high levels during their lifetimes. In
humans. EPA believes that effects from
barium on blood pressure should not
occur below 2 parts per million (ppm) in
drinking water. EPA has set the drinking
water standard for barium at 2 parts per
:n:iion (ppm) to protect against the risk
of these adverse health effects. Drinking
water that meets the EPA standard is
associated with little to none of this risk
and is considered safe with respect to
barium.
*****
(25) Aldicarb. The United States
Environmental Protection Agency (EPA)
sets drinking water standards and has
determined that aldicarb is a health
concern at certain levels of exposure.
Aldicarb is a widely used pesticide.
Under certain soil and climatic
conditions (e.g.. sandy soil and high
rainfall), aldicarb may leach into ground
water after normal agricultural
applications to crops such as potatoes or
peanuts or may enter drinking water
supplies as a result of surface runoff.
This chemical has been shown to
damage the nervous system in
laboratory animals such as rats and
dogs exposed to high levels. EPA has set
the drinking water standard for aldicarb
at 0.003 parts per million (ppm) to
protect against the risk of adverse
health effects. Drinking water that meets
the EPA standard is associated with
little to none of this risk and is
considered safe with respect to aldicarb.
(26) Aldicarb sulfoxide. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that aldicarb sulfoxide
is a health concern at certain levels of
exposure. Aldicarb is a widely used
pesticide. Aldicarb sulfoxide in ground
water is primarily a breakdown product
of aldicarb. Under certain soil and
climatic conditions (e.g., sandy soil and
high rainfall), aldicarb sulfoxide may
leach into ground water after normal
agricultural applications to crops such
.is potatoes or peanuts or may enter
drinking water supplies as a result of
surface runoff. This chemical has been
shown to damage the nervous system in
laboratory animals such as rats and
cogs exposed to high levels. EPA has set
:he drinking water standard for aldicarb
sulfoxide at 0.004 parts per million (ppm)
«o protect against the risk of adverse
h<h effects. Drinking water that meets
ihe EPA standard is associated with
little to none of this risk and is
considered safe with respect to aldicarb
'Miifoxide. "•.
(27) Aidicarb suJfdne. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that aldicarb sulfone is
a health concern at certain levels of
exposure. Aldicarb is a widely used
pesticide. Aldicarb sulfone is formed
from the breakdown of aidicarb and is
considered for registration as a pesticide
under the name aldoxycarb. Under
certain soil and climatic conditions (e.g.,
sandy soil and high rainfall), aldicarb
sulfone may leach into ground water
after normal agricultural applications to
crops such as potatoes or peanuts or
may enter drinking water supplies as a
result of surface runoff. This chemical
has been shown to damage the nervous
system in laboratory animals such as
rats and dogs exposed to high levels.
EPA has set the drinking water standard
for aldicarb sulfone at 0.002 parts per
million (ppm) to protect against the risk
of adverse health effects. Drinking water
that meets the EPA standard is
associated with little to none of this risk
and is considered safe with respect to
aldicarb sulfone.
• • • • •
(46) PentacMoropheml. The United
States Environmental Protection Agency
(EPA) sets drinking water standards and
has determined that pentachlorophenol
is a health concern at certain levels of
exposure. This organic chemical is used
as a wood preservative, herbicide,
disinfectant and defoliant. It generally
gets into drinking water by runoff into
surface water or leaching into ground
water. This chemical has been shown to
produce adverse reproductive effects
and to damage the liver and kidneys of
laboratory animals such as rats exposed
to high levels during their lifetimes.
Some humans who were exposed to
relatively large amounts of this chemical
also suffered damage to the liver and
kidneys. This chemical has been shown
to cause cancer in laboratory animals
such as rats and mice when the animals
are exposed to high levels over their
lifetimes. Chemicals that cause cancer in
laboratory animals also may increase
the risk of cancer in humans who are
exposed over long periods of time. EPA
has set the drinking water standard for
pentachlorophenol at 0.001 parts per
million (ppm) to protect against the risk
of cancer or other adverse health
effects. Drinking water that meets the
EPA standard is associated with little to
none of this risk and is considered safe
with respect to pentachlorophenol.
3. Section 141.50 is amended by
adding paragraphs (a)(15). (b)(4)."(b){5),
and (b)(6) to read as follows:
§ 141.50 Maximum contaminant level
goals for organic chemicals.
(a) • ' •
(15) Pentachlorophenol
(b) * * •
Contaminant
MO.G
:: A.d;cars o.OOi
•5) Aidicarb sulloxida Q.OQI
(5) Aidicarc sultone O.Q01
9. Section 141.51 is amended by
adding paragraph (b)(3) as follows:
§141.51 Maximum contaminant level
goals for Inorganic contaminants.
• • • • •
(b) ' * *
Contaminant
MCLG
(3) Barium
10. Section 141.61 is amended by
adding to the table paragraphs (c)(2),
(c)(3), (c)(4), and (c)(16) to read as
follows:
Maximum contaminant levels for
organic contaminants.
# * • * *
(c) • * *
CAS (40.
Conlamran
MCL
(2) 116-06-3..
(3) 1646-87-3
(4) 1646-87-4-_
(16) 87-86-5-
0.001
11. In § 141.62, paragraph (b)(l) is
revised and (b)(3) is added to read as
follows:
§ 141.62 Maximum contaminant level* for
Inorganic contaminants.
(b)
Contaminant
MCL
(mg/l)
(••) Fluoride..
(3) Barium....
40
2
-------
Federal Register / Vol. 56. No. 126 / Monday. July 1. 1991 / Rules and Regulations 30281
PART 142-NAT10NAL PRIMARY
DRINKING WATER REGULATIONS
IMPLEMENTATION
12. The authority citation for part 142
continues to read as follows:
Authority: 42 U.S.C. 300g. 300g-l, 300g-2,
3003-3. 300g-4. 300g-5. 300g-6, 300J-4 and
300J-9.
13. In § 142.57, which was published
January 30.1991 (56 FR 3526) and will
become effective July 30.1992,
paragraph (b) is revised to read as
follows:
§ 142.57 Bottled Water, Pobrt-of-UM.
* • • • •
(b) Public water systems using bottled
water as a condition of obtaining an
exemption from the requirements of
§5 141.61 (a) and (c) and 8 141.62(b)
must meet the requirements in
§ 142.62(g).
PART 143—NATIONAL SECONDARY
DRINKING WATER REGULATIONS
14. The authority citation for part 143
continues to read as follows:
Authority: 42 U.S.C 300g-l(c). 3OOH and
300j-fl.
15. In S 143.4, which was published
January 30.1991 (56 FR 3526) and which
will become effective July 30.1992,
paragraphs (b) (12) and (13) are revised
to read as follows:
§143.4 Monitoring.
* * * t •
(b) * ' *
(12) Aluminum—Method ' 202.1
Atomic Absorption Technique-Direct
Aspiration; or Method 2 306A: or
Method » I-305i-85. or Method ' 202.2
Atomic Absorption-Graphite Furnace
Technique; or Method 2 304: or Method *
1 "Methods of Chemical Analyst* of Water and
Wastes." EPA. Environmental Monitoring and
Syitama Laboratory. Cincinnati OH 40268. EPA
600/4-79-020. March. 1983. Available from ORD
Publication. CERL EPA. Cincinnati. OH 45288.
* "Standard Method* for the Examination of
Water and Wastewater." 16th Ed, American Public
Health Association. American Waterworks
Association, Water Pollution Control Federation.
1985.
• "Method* for tht Determination of Inorganic
Substances in Water and Fluvial Sediment*."
Technique* of Water-Resource* Investigation* of
the United State* Geological Survey Book*. Chapter
Al. 1985. Available from Open File Service*
Section. Western Distribution Branch, U.S.
Geological Survey. Denver Federal Center. Denver.
CO 80255.
4 "Determination of Metal* and Trace Elements
by Inductively Coupled Plasma-Atomic Emission
Spectrametry." Method 200.7. version 3.2. August.
1990. EPA Environmental Monitoring and System*
Laboratory. Cincinnati. OH 45268.
200.7 Inductively-Coupled Plasma
Technique; or Method * 200.8
Inductively Coupled Plasma-Mass
Spectrometry or Method * 200.9 Platform
Technique: or Method ' 3120B
Inductively-Coupled Plasma Technique.
(13) Silver—Method > 272.1 Atomic
Absorption Technique-Direct
Aspiration; or Method * 324A: or
Method * 1-3720-85; or Method ' 27^2
Atomic Absorption-Graphite Furnace
Technique; or Method * 304: or Method *
200.7 Inductively-Coupled Plasma-
Technique; or Method • 200.8
Inductively-Coupled Plasma-Mass
Spectrometry: or Method • 20O9
Platform Technique; or Method * 3120B
Inductively-Coupled Plasma-Technique.
[FR Doc. 91-15564 Filed 6-28-01:8:43 wn|
BILLMO CODE U69-SO-M
• "Determination of and Trace Element* in Water
and Waste* by Inductively Coupled Plasna-Mas*
Spectrometry." Method 200A vers>o»4J. Aagwt
1900. EPA, Environmental Monitorial eari System*
Laboratory. Cincinnati. OH 45268. A**slak*» froat
ORD Publication, CERL EPA, CindnMCOH 45288.
• "Determination of Metal* and Traes) Elements
by Stabilised Temperature Graphite Furnace
Atomic Absorption-Spectrometry.' Method 200.9.
version 1.1. August 1990. EPA. Environmental
Monitoring and System* Laboratory. Cincinnati. OH
45268.
' "Standard Method* for the Examinatios) of
Water and Wastewater." 18th «d_ AaaericafrPubric
Health Association, American Waterworks
Association. Water Pollution Control Fedaatkni.
1985.
-------
United States Otfire of Pecriciaes and 7o>ic Sec-nance-;
Environmental Protetr.ion Office 01 Penicae Procrams (TE-7S6C!
Agency Wash i no ion, DC 20460
&EPA Pesticide
Fact Sheet
Name of Chemical: ALACHLGR
Reason for Issuance: SPECIAL REVIEW
Date Issued: DEC I 4 jggy
Fact Sheet Number: 97>1 •:
Description of the Chemical >-'--•
Chemical name: 2-chloro-2'-6'-diethyl-N-(methoxymethyl)-
acetanilide
Common name: Alachlor
Trade names: Lasso®, Pillarzo®, Alanex®
EPA Shaughnessy number: 090501
Chemical abstracts service (CAS) number: 15972-60-8
Year of initial registration: 1969
Pesticide type: Herbicide
Chemical Family: Acetanilide
Use Patterns and Formulations
Application sites: preemergent use on field corn (incluc
sweet corn, popcorn), soybeans,
peanuts, dry beans, lima beans, green
cotton, grain sorghum, sunflowers, or
plants.
Types of formulations: emulsifiable concentrate, granula
microencapsulate
Types and methods of application: ground or aerial methc
.Application rates: rate and frequency vary according to
site application; typically 1 to 4 po
of active ingredient per acre.
-------
D h -. •
: es
Coicr
i-'i e 11 i n g Point
Specific Gravity
Solubilitv
Physical and Chemical Properties:
Octanol/Water Partition
Coef f i cient
Stability
Appearance at room
temperature
White
40 to 41°C
1.133 (25/15.6°C)
Soluble in ether, acetone,
benzene, alcohol (unspecified!
and ethyl acetate; slightly
soluble in hexane; solubility
in water - 240 ppm
434
Stable (first detectable heat,
evolution at 105°C)
White, crystalline solid at
23°C
Tolerance Assessment; Tolerances were established in 40 CFR
180.249 for residues of alachlor and
its metabolites. ;/
Toxicology Summary:
Acute toxicity - Technical alachlor is not an acutely
toxic product by any route of exposure. The acute oral
LD5Q in rats is .93 g/kg (Category III), the acute dermal
LD5Q in rabbits is 13.3 g/kg (Category III), and alachlor^
does not cause significant eye or skin irritation in rabbits
(Category IV).
Chronic Toxicity - Alachlor is oncogenic in both mice and
rats. In mice, alachlor causes a statistically significant
increase in lung bronchioalveolar tumors in females at
260 mg/kg/day (Highest Dose Tested). In rats, alachlor causes
statistically significant increases at 42 mg./kg/day and above
in nasal turbinate and stomach tumors in both sexes and thyroid
follicular tumors in males. The following No Observed Effect
Levels .(NOELS) have been established for non-oncogenic effects:
1 mg/kg/day for liver and kidney effects; 2.5 mg/kg/day for
uveal degeneration syndrome (UDS) of the eyes; 10 mg/kg/day
for reproductive effects to kidneys of offspring. No birth
defects were seen in highest dose tested for rats (400 mg/kg
/day), but an additional "teratogen icJ.ty study in rabbits is
pending completion in 1983. ... .
-------
cf Acer.cv s Reculatcrv Positi;
Tne Acency position :s that current registrations for
the u^e cf alachlor z-r. agricultural and nonfood crops will
be allowed to continue provided the following conditions and
label modifications are met to reduce aoolicator exoosure:
-ecas
s i f icat ior. as restricted use pesticide
-,e application of alachlor is restricted to use by
=rtified applicators or persons under their direct
.jper vision.
b. Continue use of tumor warning on label.
The following tumor warning statement imposed in the
alachlor Registration Standard must remain on the label:
"The use of this, product may be hazardous to
your health. This product contains alachlor
which has been determined to cause tumors
in laboratory animals."
c. Require the use of mechanical transfer devices by
all mixer/loaders and/or applicators who treat
300 acres or more annually with alachlor.
d. Reinstate aerial application on the alachlor label
with the following additional label restriction:
"Human flacgers prohibited. Aerial application
may be performed using mechanical flaggers only."
The Agency has determined that the upper bound U.S. dietary
risk from alachlor residues on food crops is in the range of
lO"^ (approximately one increased tumor case per million
persons exposed) based on the actual percent of crops treated w:
alachlor. The Agency believes this risk is reasonable given the
benefits of continued use.
The Agency has determined that the risks associated with
alachlor exposure through ground water cannot be adequately
assessed at thi.c time. The true extent of alachlor occurrence
in ground water is not known and cannot be properly estimated
for most areas of the country. Further monitoring will be
necessary considering the large volume, multiregional use of
alachlqr, and the lack of statistically representative data fror.
the available studies. The Agency's final evaluation of the
-------
cate
potential ror a_acr.ic-r centan\inat ion cr crounc w^ter
deferred, pending receipt of required monitoring data being
generated by the registrant under an EFA-approved protocol.
This study is scheduled for completion in late 19S9, and t: •
results will be evaluated by EPA in early 1990.
Existing data on aiachlor residues in surface water in<
that the risk fro-, drinking water sources supplied by surface water
will generally not exceed a range of 10~°. The Agency believes
this level of risk is reasonable given the benefits of continued.
use of aiachlor products, and is not proposing regulatory action
under FIFRA on aiachlor residues in surface water. The Agency
plans to promulgate regulations establishing a Maximum Contaminant
Level (MCL) for aiachlor under the Safe Drinking Water Act in
the near future. These regulations, would require the treatment
of drinking water which contains aiachlor residues in excess of
the MCL, thereby maintaining the level of risk from exposure at
reasonable levels.
5. Contact person:
James V. Roelofs
Review Manager
Special Review Branch
Registration Division (TS-767C)
Office of Pesticide Programs
U.S. Environmental Protection Agency
Washington, D.C. 20460
(703)-557-0064
DISCLAIMER: The information in this Chemical Information
Sheet is for informational purposes only, and
may not be used to fulfill data requirements
for pesticide registration or reregistration.
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ftvuean O«iM •< P
. DC
•^
Pesticide
Fact Sheet
Name of Chemical:
Reason for'Issuance: SPECIAL REVIEW p° 2/3
•ste Issued: JUN 2 2 1988
Fact Sheet Number: '
DESCRIPTION OF CHEMICAL
Common Name: Aldicarb
Chemical Name: 2-Tnethyl-2-(methylthio)propionaldehyde
0-(methyIcarbamoyl)oxime
CJass Description: Member of the carbamate family
Trade Name: Temik
EPA Shaughnessy Code: 098301
Chemical Abstracts Service (CAS) Number: 116-06-3
Year of Initial Registration: 1970
Pesticide Type: Insecticide, acaricide, nematicide
U.S. and Foreign Producer: Rhone-Poulenc (formerly Union
Carbide Agricultural Chemical Co.)
USE PATTERNS AND FORMULATIONS
Aldicarb is currently registered for use only on cotton,
potatoes, citrus, peanuts, soybeans, sugar beets, pecans,
tobacco, sweet potatoes, ornamentals, seed alfalfa, grain
sorghum, dry beans, and sugar cane.
Types and Methods of Application: Soil incorporated.
Application Rates: 0.3 - 10.0 Ibs. active ingredient.
Types of Formulation: Granular formulation (15%, 10%, and
5%). Also as a granular in a mixture with the fungicides
pentachloronitrobenzene and 5-ethoxy-3-(trichloromethyl)-l,2,4-
thiadiazoie.
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Aldicarb Fact Sheet (cont
-2-
SCIENCE FINDINGS
Chemical Characteristics: Technical aldicarb is a white
crystalline solid with a melting point of 98-100 C (pure
material). Under normal conditions, aldicarb is a heat-
sensitive, inherently unstable chemical and must be stabilized to
obtain a practical shelf-life.
Toxicological Characteristics:
Aldicarb is a carbamate pesticide which causes cholin-
esterase (ChE) inhibition at very low exposure levels. It is
highly toxic by the oral, dermal, and inhalation routes of
exposure (Toxicity Category I). The oral LDso value for
technical aldicarb is 0.9 mg/Xg and 1.0 mg/Xg for male and
female rates, respectively. The acute dermal LDso for aldicarb
in rats is 3.0 mg for males and 2.5 mg for females. Rats, mice
and guinea pigs were exposed to aldicarb, finely ground, mixed
with talc, and dispersed in the air at a concentration of 200
mg/m3 for five minutes; all animals died. At a lower
concentration (6.7 mg/M3; a 15 minute exposure was not lethal;
however, 5 of 6 animals died during a 30 minute exposure.
Exposure of rats for eight hours to air that had passed over
technical or granular aldicarb produced no mortality. Aldicarb
applied to the eyes of rabbits at 100 mg of dry powder caused ChE
effects and lethality.
The toxicity data base for aldicarb is complete. The
toxicity data base includes a 2-year rat feeding/oncogenicity
study which was negative for oncogenic effects at the no-
observed-effect-level (NOEL) of 0.3 mg/Xg bw/day; a 100-day dog
feeding study and a 2-year dog feeding study with NOELs of 0.7
and 0.1 mg/Xg bw/day, respectively, for effects other than
cholinesterase inhibition (highest levels tested (HLT)); an 18-
month mouse feeding/oncogenicity study with a NOEL of 0.7 mg/Xg
bw/day which was negative for oncogenic effects at the levels
tested (0.1, 0.3, and 0.7 mg/Xg bw/day); a 2-year mouse onco-
genicity study which was negative for oncogenic effects; a 6-
month rat feeding study using aldicarb sulfoxide with a NOEL of
0.125 mg/Xg bw/day for ChE inhibition; a 3-generation rat
reproduction study with a 0.7 mg/Jcg bw/day NOEL; a rat teratology
study which was negative for teratogenic effects at 0.5 mg/Xg
bw/day (HLT); a hen neurotoxicity study which was negative at up
to 4.5 mg/Xg bw/day; a mutagenicity study utilizing the rat
hepatocyte primary culture/DNA repair test which was negative for
mutagenic effects at 10,000 ug/well; and a mutagenicity test
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Aldicarb Fact Sheet (cont.)
_ 3 _
utilizing an ii; vivo chromosome aberration analysis in Chinese
hamster ovary cells which was negative for mutagenic effects at
500 ug/ml.
Physiological and Biochemical Behavioral Characteristics:
Aldicarb and its metabolites are absorbed by plants from
the soil and translocated into the roots, stems, leaves, and
fruit. The available data indicate that the metabolism of
aldicarb in plants and small animals is similar.
Aldicarb is metabolized rapidly by oxidation to the
sulfoxide metabolite and followed by a slower oxidation to the
sulfone metabolite, which is 25 times less acutely toxic than
aldicarb. Both metabolites are subsequently hydrolyzed and
degraded further to yield less toxic entities. Available
studies demonstrate that the administration of aldicarb to a
lactating ruminant results in the rapid metabolism and
elimination of the material. No residues of the parent compound
and little, if any, residues of aldicarb sulfoxide or aldicarb
sulfone are found in the tissues and milk. The predominant
residue detected in tissues and milk is aldicarb sulfone nitrile
Environmental Characteristics:
Sufficient data are available to assess the environmental
fate of aldicarb. From the available data, aldicarb has been
determined to be mobile in fine to coarse textured soils, even
including those soils with high organic natter content, and has
been found to reach ground water. Aldicarb is not expected to
move horizontally from a bare, sloping field. Therefore,
accumulation of aldicarb in aquatic nontarget organisms is
expected to be minimal. This is further supported by an
octanol/water partition coefficient of 5 and an ecological
magnification value of 42.
Ecological Effects:
Aldicarb is highly toxic to mammals, birds, estuarine/marine
and freshwater organisms. LC50 values for the bluegill sunfish
and rainbow trout have been reported as 50 ug/liter and 560
ug/liter, respectively. A LC50 of 410.7 ug/liter was reported
for Daphnia maona. Studies on the toxicity of aldicarb to the
mallard duck and the bobwhite quail indicate LD50 values of 1.0
and 2.0 mg/kg, respectively.
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Aldicarb Fact Sheet (cont.)
-4-
Limited exposure to mammals is expected from a dietary
standpoint. However, data from field studies and the use history
of aldicarb provide sufficient information to suggest that
application of this pesticide may result in some mortality, with
possible local population reductions of some avian species.
Whether these effects are excessive, long-lasting, or likely to
diminish wildlife resources cannot be stated with any degree of
certainty. Therefore, additional field studies have been
required to further quantify the impact on avian and small mammal
populations. Field study results will be submitted in April
1988.
Aldicarb has also been found to pose a threat to the
endangered Attwaters Greater Prairie Chicken, living in or near
aldicarb-treated fields. Accordingly, all aldicarb products are
required to bear labeling restrictions prohibiting the use of the
product in the Texas counties of Aransas, Austin, Brazoria,
Colorado, Galveston, Goliad, Harris, Refugio, and Victoria if
this species is located in or immediately adjacent to the
treatment area.
Tolerance Assessment:
The Agency is in the process of reassessing the existing
tolerances for aldicarb. Processing studies for coffee and
potatoes have been submitted and are acceptable. A large animal
metabolism study has been submitted to the Agency and satisfies
the data requirement. A completed study of aldicarb residues on
soybean processing fractions is to be submitted by August 1988.
The requirement to submit a study analyzing aldicarb residues on
treated cotton forage has been satisfied with a label restriction
prohibiting the feeding of treated forage to livestock.
Exposure Incidents:
In 1979, aldicarb residues were found in drinking water
veils located near aldicarb treated potato fields in Suffolk
County, Long Island, New York, at levels greater than 200 parts
per billion (ppb). Subsequently, aldicarb has been detected in
ground water in 48 counties within 15 other States at levels up
to 515 ppb. In all, the Agency has evaluated over 35,000 ground
water samples of which 32% were positive for residues of
aldicarb. The Agency's Office of Drinking Hater (ODW) has
established a Health Advisory level (HA) of 10 ppb for residues
of aldicarb in drinking water.
The Pesticide Incident Monitoring System (PIMS) reports on
aldicarb, from 1966 through 1982, contained 165 incidents
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Aldicarb Fact Sheet (cent.
-5-
associated v human injury. Most of the human incidents
alleged that aicarb was the cause of the problem, but there
was insuffic ; evidence to support such a conclusion. Those
incidents in ying confirmed aldicarb poisonings appeared to be
the result c -ailure to use label recommended safety equipment
while applying aldicarb. Other incidents resulted from acci-
dental spillage, ingestion of aldicarb, or consumption of food
commodities improperly treated with aldicarb.
The largest documented episode of foodborne pesticide
poisoning in North American history occurred in July 1985 from
aldicarb-contaminated California watermelons. More than a
thousand probable cases vere reported from California, Oregon,
Washington, Alaska, Idaho, Nevada, Arizona and Canada. The
spectrum of illness attributed to aldicarb ranged from mild to
severe and included cases of grand mal seizures, cardiac
arrhythmias, severe dehydration, Jbronchospasms, and at least two
stillbirths occurring shortly after maternal illness. The
prompt embargo of watermelons on July 4, 1985 abruptly terminated
the major portion of the outbreak and reported illnesses
occurring after the implementation of the watermelon certifi-
cation program were far fewer and milder in comparison to
earlier cases. Contamination of the watermelons ranged up to 3.3
ppm of aldicarb sulfoxide (ASO), a metabolite of aldicarb.
Clinical signs occurred from exposures to dosages estimated to be
as low as 0.0026 mg/kg ASO.
SUMMARY OF REGULATORY POSITION AND RATIONALE
a. Dietary Exposure to Treated Food Commodities
The Agency has recently received the final results of a
National Food Survey which monitored raw agricultural commodities
for residues of aldicarb in the market place. After these data
have been evaluated, the dietary exposure from consuming treated
food commodities will be estimated, and a risk assessment will
be conducted. The Agency may propose further regulatory action
depending on the results of this study.
b. Dietary Exposure to Contaminated Ground Water
The Agency has concluded that there are unacceptable risks
to persons consuming drinking water that is contaminated with
aldicarb at levels greater «•*"»•» the HA of 10 ppb due to a reduced
margin of safety for ChE inhibition.
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Aldicarb Fact Sheet (cont.)
-6-
The Agency cannot identify all specific areas of the nation
where aldicarb residues exceed the HA, or the number of people
who would be exposed to these high levels of contamination.
However, the Agency can predict certain areas of the nation
where the ground water supplies have a relatively high vulnera-
bility to aldicarb contamination due to the hydrogeology and/or
agronomic practices found in that area. Additionally, the Agency
can predict certain areas which would have a medium vulnerability
to contamination, although the vulnerability within some of these
.areas could vary greatly with some areas being much more
vulnerable.
It is the Agency's presumption that the risks posed by
aldicarb contamination of ground water above the HA in current or
potential drinking waters will likely be more significant, in
almost all cases, than any local benefit derived from aldicarb's
continued use. Consequently, the Agency is proposing to regulate
the use of aldicarb in order to eliminate or prevent contam-
ination of ground water at levels above the HA. As a basic
level of protection for all areas where aldicarb is used, the
Agency is proposing a number of restrictions on the label.
Specifically, no use of aldicarb would be permitted within 300-
feet of a drinking water well, and aldicarb would be classified
as a restricted use pesticide due to ground water concerns.
(Aldicarb is already classified as a restricted use pesticide due
to its acute toxicity.) Additionally, the Agency is seeking
public comment as to what, if any, additional measures should be
considered regarding the use of aldicarb and site-conditional
restrictions.
The Agency will also require monitoring in those areas
classified as having a medium tendency to leach. The data
generated will be used to determine whether further regulatory
action is required in these areas.
Finally, for those areas where there is the greatest
likelihood of ground water contamination, states will need to
implement, either for the entire state or for a county(ies)
within the state. State Pesticide Ground Water Management Plans
(MPs). Briefly, MPs are comprehensive plans which describe the
measures states will impose to prevent ground water contam-
ination. The Agency believes that MPs provide the best method of
protection ground water pesticide contamination.
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Aldicarb Fact Sheet (cor.t.)
-7-
The Agen^ s soliciting public comment on a number of
issues regard: its preliminary determination for aldicarb.
Included are c ;tions regarding the components of an MP, which
assessment (hy igeologic region or county) should be used in
identifying th-.a areas where contamination is most likely to
occur, how should a localized risX/benefit analysis be performed
and who should conduct it, and who is responsible for the costs
associated with cleaning up ground water contamination.
CONTACT PERSON
Bruce Kapner
Special Review Branch, Registration Division
Office of Pesticide Programs (TS-767C)
401 M Street, S.W.
Washington, D.C. 20460
(703) 557-1170
DISCLAIMER: The information presented in this Pesticide Fact
Sheet is for informational purposes only and may not be used to
fulfill data requirements for pesticide registration or reregistration
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Unrted States Office of Pesticide ir>d Toxic Substances
Environmental Proteciior. Office of Pesticide Programs (TS-766C1
Agency Washtrwton. DC 20460
&EPA Pesticide
Fact Sheet
Name of Chemical: .i
-
Reason for Issuance: xe« Che-ical Registrar!
Date ISSUed: January 15, 1986
Fact Sheet Number: --=>
DESCRIPTION OF CHEMICAL
Ger.e r i c Name : 2-methyl-2-(methylsulfor. yl) propar.al-0- ( methyl am i r.o
carbonyl oxirael)
Comraor. Name: Aldoxycarb
Trade Name: Star.dak
Other Names: Sulfocarb, Aldicarb sulfor.e
EPA Shaughr.essy Code: 110801
Che-ical Abstracts Service (CAS) Number: 1646-88-4
Year of Initial Registration: 1986
Pesticide Type: Insect i c ide/Nemat ic ide
Chemical Family: Carbamate
U.S. Producer: Union Carbide Agricultural Products Co., Inc.
No other producer at this time
USE PATTERNS AND FORMULATIONS
Appl icat ior. Sites; Containerized honey locust trees
(Commercial Use Only) to control honey
locust gall midge
Type of Formulations ; Insecticide/fertilizer spike; registered
to International Spike, Inc.
Method of Application; Spike is inserted into soil in
container
Application Rate; One or more spikes of 1% active ingredient
per container, depending on size of container
or plant.
Usual Carriers; Formulation is a pressed mixture of aldoxycarb
and fertilizer chemicals.
-------
SCIENCE FINDINGS
i
-------
Neurotoxicity: Not an acute delayed r.eurotoxic agent at coses
up to 250 rng/kg (highest dose tested (HOT)).
Or.coger. i ci t y: Two studies, rat ar.d mouse. Both are acceptable
ar.d are negative for or.coger.ic effects up to 9.6
mc/kg/day (HOT).
Teratoger.ici t y: Two teratology studies, rat ar.d rabbit have
beer, evaluated to determine the teratoger.ic
potential of aldoxycarb. Both studies were
negative for teratogenic effects at levels up
to 9 .6 mg/kg ( HOT) .
Reprocuction/3-generat ion: No effects on reproduction at levels
up to 9 .6 mg/kg ( HOT) .
Metabolism: The metabolism of aldoxycarb is adequately under-
stood, it is metabolized by hydrolysis of the
carbamate ester to form the oxime. Other reactions
of the oxime occur.
Mutagenicity: Adequate studies are available to demonstrate
aldoxycarb is not a mutagen.
Physiological and Biochemical Behavioral Characteristics
Mechanism of Pesticidal Action: A systemic insect icide/r.emati-
cide which causes reversible carbamylation of the acetocholine-
sterase enzyme of tissues, allowing accumulation of acetyl-
choline at cnolinergic neuroeffector junctions (muscarinic
effects) and at skeletal muscle myoneural junctions and in
autor.o^ic ganglia (nicotinic effects). The central nervous
system is also impaired.
Symptoms of poisoning include: headache, dizziness, weakness,
ataxia, pinpoint pupils, blurred or dark vision, muscle twitching,
nausea, vomiting, diarrhea, convulsions and death. The onset
of these symptoms is rapid and their severity depends on the
dose. The immediate cause of death is usually respiratory
failure.
Metabolism and Persistence ir. Plants and Animals;
Acceptable studies have been submitted which show aldoxycarb is
metabolized in plants ar.d animals by hydrolysis of the carbamate
ester to form the oxime. Further reactions of the oxime yield
aldoxycarb aldehyde, aldoxycarb alcohol, aldoxycarb acid and
aldoxycarb nitrile. The oxime and alcohol metabolites are
easily cor.jugatd to form water soluble glycosides, sulfates,
and other compounds.
-------
In soil and water, a Idox yea ri: is very stable under acidic
conditions, stable at neutral conditions and very unstable to
hydrolysis at alkaline conditions. It is rapidly nydrolyzec to
=.ul f oca t: " cxir.e which in turn rapidly degrades to methane
sulfonic acid and 2-hydroxy i sobu t ryraldehyde oxi.me. Aldoxycarb
is rapidly Degraded to a variety of materials under both aerobic
and an>?robic conditions. In certain soils, such as those with
a sandy loam texture, it has a half-life of 2-4 weeks.
Aldoxycarb is mobile in certain soil types and does have the
potential to contaminate groundwater under certain situations.
Soil types of high sand content and organic matter will promote
leaching of parent and degradation products, which are of lower
t^xicity than that of the parent compound.
However, it is believed the containerized ornamental plant use
will not result in groundwater contamination because of the
fact that application is made to soils in containers.
Ecological Effects of Technical Aldoxycarb•
Avian oral: Mallard duck - 33.5 mg/kg
Avian dietary: vvaterfowl species (Mallard duck) - > 10,000 ppm
Upland game species (Bobwhite quail) - 5,706 ppm
Freshwater fish: Coldwater species (rainbow trout) - 42.0 ppm
Wamwater species (bluegill sunfish) - 53.0 ppm
Acute Freshwater Invertebrates: Daphnia - 0.176 ppb
Precautionary language would be required for outdoor terrestrial
use for hazards to wildlife.
4. SUMMARY OF REGULATORY POSITION AND RATIONALE
The Agency has determined to register aldoxycarb for container-
ized ornamental plants because, adequate studies are available
to assess the toxicolog ical and er.v iror.mental characteristics of
aldoxycarb ar.d its potential effects to humans from this use.
The Agency concludes from this studies that this use pattern
will not pose any unreasonable adverse effects to humans or the
environment. None of the criteria for unreasonable adverse
effects listed in section 162.1l(a) of Title 40 of the U.S.
Code of Federal Regulations have been met or exceeded for this
use .
5. SUMMARY OF MAJOR DATA GAPS
T ?re are no data gaps.
-------
6. CONTACT PERSON AT E?A
Jay B . El ler.be roe:'
Procuct Manager (12)
Insect ic ide-Rodent icide Brar.ch
Regist rat ior. Division (TS-767C)
Office of Pesticide Programs,
Environmental Protection Agency,
401 M St., S.W.
Washington, D.C. 20460.
Office location and telephone number:
Rro. 202, Crystal Mall Bldg . 2
1921 Jefferson Davis Highway,
Arlington, VA 22202,
(703) 557-2386.
DISCLAIMER: The information presented in this Chemical Information
Fact -Sheet is for informational purposes only and may not be use to
fulfill data requirements for pesticide registration and
re^ecistration.
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«nc Tone
OC
01
&EPA Environmental
Fact Sheet
AN 22 1930
ATRAZINE LABEL AMENDMENTS
BACKGROUND
Atrazine is a selective, preemergent and postemergent
herbicide used to control broadleaf and grassy weeds in corn,
sorghum, sugarcane, wheat fallow, rye, pineapple, macadamia nuts,
guava, warm season turfgrass and other noncrop areas.
Approximately 75 to 95 million pounds of atrazine are used
annua1ly.
The Agency is in the process of reviewing data submitted in
response to the 1983 Registration Standard and subsequent Data
Call-ins. Available atrazine data have raised concerns regarding
its potential oncogenic risk from dietary and non-dietary
exposure, and concern about the widespread contamination of
ground water due to atrazine use.
^he Agency has classified atrazine as a Group C carcinogen
(possible human carcinogen), based on increased incidence of
mammary tumors in female rats. The Agency presented its position
on Atrazine to the Science Advisory Panel (SAP) and the SAP
agreed with the classification.
Atrazine shares the characteristics of other triazine
herbicides which make it a ground-water contaminant: high
leaching potential, high persistence in soils, slow hydrolysis,
low vapor pressure, moderate solubility in water, and moderate
adsorption to organic matter and clay.
The Agency's Office of Drinking Water has proposed a Maximum
Contaminant Level (MCL) of 3 ppb.
Compilation of ground-wauer monitoring data by the Agency,
cites numerous studies in which atrazine was detected in
approximately 4 percent of nearly 15,000 wells.
-------
Although the overall percentage of atrazine detections is
relatively small, the percentage greatly increases in high-use
areas with vulnerable hydrogeologic environments. An even more
important factor in the relatively high frequency of atrazine
detections in ground water is its high volume of use.
RISK REDDCTION MEASURES
In November of 1988, all technical registrants of atrazine
voluntarily submitted identical label amendments which were
intended to reduce exposure and risk from use of atrazine
products. The amendments are now being approved with
comments/revisions.
This voluntary action by technical registrants is
commendable, and it is expected that most products will bear the
new labels for the 1991 growing season. The Agency wishes to
emphasize however, that the risk reduction afforded may not be
adequate. Therefore, these label revisions are likely to be
supplemented by additional measures in the future. In
particular, certain of the label revisions intended to address
ground-water contamination, such as the statements regarding
storage and mixing/loading activ_ties, will only address point-
source contamination. The Agency is finalizing its ground-water
strategy and is continuing its assessment of atrazine monitoring
data. While these label amendments are being approved, the
Agency's continued investigation of exposure" and risk may
necessitate additional measures in the future, particularly with
regard to non-point source contamination.
The Agency and the registrant recognized the importance of
an extensive notification plan to quickly and properly
communicate to users the revisions that have been made to reduce
the risks associated with atrazine. The modifications will be
accomplished by revising atrazine labels with the modifications
described above, such that no product will be released for
shipment without the new labels after September 1, 1990. The
Agency will not require relabelling of products in the channels
of trade.
Label Modifications
Ose of the protective clothing required by the label will
reduce exposure to users, mixer/loaders and applicators of
atrazine. Users are required to wear long sleeve shirts and long
pants, chemical resistant gloves and waterproofed boots.
Mixer/loaders are required to use chemical resistant rubber or
-------
neoprene .gloves and a face-shield or goggles. Included in these
measures is the reclassification of atrazine as a restricted _3e
pesticide based on ground-water concerns. The label advises tr.at
ground-water contamination may be reduced by diking and flooring
bulk storage sites with impermeable material. It requires that a
50 foot buffer be set between areas of application,
mixing/loading, and sink holes or wells. Rate reductions consist
of a maximum application rate for corn and sorghum of 3 Ibs a.i.
per acre per year, and application rates to non cropland for
industrial weed control of 10 Ibs a.i. per acre per year.
Treatment limitations restrict post-emergence application to
treatments made before corn and sorghum reach 12 inches in
height.
The approval of these technical labels differs from EPA's
usual practice in that only end use products would normally bear
such label language. However, in this case, the approval of the
technical labels will set the tone for the subsequent submission
of the 150 end use labels. After September 1, 1990, no technical
atrazine product will be released for shipment without the new
labels. It will be considered a violation of the technical label
to formulate end use products after that date which do not bear
the new label. The restrictions would not apply to lawn care
products with less than 2% atrazine active ingredient.
EPA Contact (s)
Robert J. Taylor (RD/FHB) (703) 557-1800
Jude Andreasen (SRRD/SRB) (703) 557-1170
-------
United Statw CcMtniotiera
L... LI ••!!•' Protection Pv»ltc At»ir*
SrEPA Environmental News
TUESDAY, KAY 14, 1991
PESTICIDE CARBOFURAN PHASED OUT UNDER SETTLEMENT AGREEMENT
Al Heier 202-382-4374
The U.S. Environmental Protection Agency announced today that
it has reached an agreement with FMC Corp. of Philadelphia to phase
out the sale and use of the granular formulations of the pesticide
carbofuran for all but five minor uses by Sept. 1, 1994. In
addition, the use of granular carbofuran will be .banned in certain
ecologically sensitive areas beginning Sept. 1, 1991. FMC Corp. is
the only manufacturer and registrant of granular carbofuran.
Liquid carbofuran was not considered in the settlement agreement.
Today's action follows a 1989 proposal by EPA to ban granular
formulations of carbofuran (trade name Furadan) based on evidence
that carbofuran granules, are acutely toxic to birds. A single
granule may kill a small bird. Carbofuran has killed many birds,
including endangered species such as the bald eagle.
EPA has received more than 80 separate reported bird-kill
incidents attributed to carbofuran granular use in several crops
throughout the country and has reviewed eight field studies in 10
states. The Agency concluded that dietary exposure to birds
occurred from direct ingestion of granules and ingestion of soil
invertebrates such as earthworms contaminated with carbofuran.
Secondary poisoning of birds of prey ingesting small birds or
mama Is contaminated with., carbofuran also occurred.
The complete' human health data base ge?ierally does not show
any human health concerns. Carbofuran is widely used to control
nematodes (root worms) and insects on corn, sorghum, rice and other
fields vegetable and fruit crops.
"This agreement will dramatically reduce risks to birds in .a
R-84 (more)
-------
-2-
short period of tine and will avoid a lengthy cancelation process,"
said EPA Administrator, William K. Reilly. "It provides an orderly
timetable for phasing out all but a handful of minor uses in a
number of limited places."
After Sept. 1, 1994, FMC's sales of granular carbofuran will
be limited to no more than 2,500 pounds per year. Use will be
limited to five crops: bananas in Hawaii, spinach grown for seed,
pine tree progeny tests, cucurbits (cucumbers, squash, pumpkins,
cantaloupe and watermelons) and dry-harvested cranberries.
Under terms of the agreement, the sale of granular carbofuran
for use on corn and sorghum will be prohibited after Sept. 1, 1993,
for use on rice after Sept. 1, 1994 and for use on bananas in
Puerto Rico after Sept. 1, 1994. The use of carbofuran on bananas
in Hawaii, dry-harvested cranberries, cucurbits, pine tree progeny
tests and spinach grown for seed will be allowed to continue
indefinitely. All., other uses of granular carbofuran will .be
voluntarily deleted from the label effective Sept. 1, 1992. During
the phase-out period, FMC sales of granular carbofuran will be
limited as follows:
- between Sept. 1, 1991 and Aug. 31, 1992, no more than 4.5
million pounds of active ingredients may be sold;
- between Sept. 1, 1992 and Aug. 31, 1993, no more may be sold
than the difference between 4.5 million pounds and the amount sold
during the period of Sept. 1, 1991 and Aug. 31, 1992;
- between Sept* 1, 1993 and Aug. 31, 1994, no more may be sold
than the difference between 4.5 million pounds and the total amount
sold during the previous two years, but in any event, no more than
400,000 pounds.
- beginning Sept. 1, 1994 FMC will be allowed to sell no more
than 2,500 pounds of granular carbofuran annually and use will be
limited to bananas in Hawaii, dry-harvested cranberries, cucurbits,
pine tree progeny tests and spinach grown for seed.
In addition to the annual .sales reduction of granular
carbofuran, certain geographic restrictions to protect birds in
ecologically sensitive areas, and a. prohibition of the foliar
application on corn go into effect Sept. 1, 1991. The geographic
restrictions for all granular carbofuran includes a prohibition
against any use (except for the five remaining crops as noted
above) in the states of Connecticut, Delaware, Florida, Maine,
Maryland, Massachusetts,- New Hampshire, Rhode Island, Vermont and
Virginia. Granular carbofuran use will also be prohibited in the
R-84 (more)
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(3)
coastal counties of the states of North Carolina, Oregon, .
Carolina and Washington and from use on corn and sorghum
California.
Remaining stocks of granular carbofuran in the hands of
growers and distributors labeled for use on corn and sorghum may
be sold and used for one year after the phase-out, until Aug. 31,
1994. Similarly, granular carbofuran labeled for use on rice may
only be sold and used until Aug. 31, 1995.
Granular carbofuran is generally applied when seeds are being
planted at the beginning of the growing season to control pests
that may or may not occur later in the season. In 1988, EPA
estimated that seven to 10 million pounds of carbofuran active
ingredients were used, about 80 percent of which was the granular
formulation. Use of carbofuran on corn,- the primary crop use, has
declined by an estimated 33 percent since the late 1970's.
During the course of the special review of carbofuran which
began in 1985, EPA-xeviewed and evaluated a number of options other
than cancellation to reduce the risk to birds. Among these
measures were the following: additional precautionary labeling
regarding the hazard to birds, limiting carbofuran use to certain
months of the year, limiting application geographically, and,
limiting application rates. EPA found that none of these risk
reduction measures were adequate to reduce the risk to birds, given
the high toxicity of carbofuran granules.
The agreement in principle between EPA and FMC Corp. has been
signed. To effect this agreement, FMC is expected to amend their
granular carbofuran registrations by June 1. The agreement will
effectively conclude the Agency's Special Review of granular
carbofuran.
R-84 # # #
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(jnnie Strt« OHia o< Pvttoflli *nd Tone Sutattneot
Enrwonrnwiai ^roitciwr, Otl.ct of tmtiaci *ro*r»mi (TV7MC;
ri. OC
vyEPA Pesticide
Fact Sheet
Name of Chemical: Carbofuran
Reason for Issuance: Soecial Review—Preliminary Det
Date Issued: January 5, 19S9
Fact Sheet Number:
1. DESCRIPTION OF CHEMICAL
CorrjTiCn Name: Carbcfuran
Che-i ral N'ne: 2,3-dihydro-2,2-cimethyl-7-benzofurany1
me thyIcarbanaie
Chemical Family: Carsamate
Trafe Na-e: Furadar.'
E?A Shaurhn.essy Code: 090601
Cr.e-iral Abstracts Service (CAS) Nu-ber: 1563-66-2
Year cf Initial Registration: 1969
Pesticide Type: Insecticide, ner.aticide
U.S. Producer: FMC Corporation
2. USE PATTERNS AND FORMULATIONS
Carbofuran is currently registered on a variety of fruit
and field crops, vegetables, tobacco, ornamentals, and
forest tree seedlings. Approximately 7 to 10 million
pounds of active ingredient (Ib ai) are applied to these
sites per year. From 6 to 9 million Ib ai of the annual
usage is accounted for by the granular formulation. The
carbofuran granular formulation was placed in Special
Review in 1985 base-J on the avian hazard.
Types and Methods of Application: Aerial and ground.
Application Rates: 0.1 to 19.9 Ib ai/acre (granular)
0.05 to 10.1 Ib ai/acre (flowable)
Types of Formulations: Granular, flowable, and wettable
powder formulations and a spike
product.
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SCIENCE FINDINGS
Chemical Characteristics:
Physically, technical carbcfuran is a white crystalline
solid that has a melting point cf 123 to 154 *C (pure material
Carbcfuran is stable under natural or acidic conditions and is
unstable under alkaline conditions.
lexicological Characteristics:
• The Agency evaluated information concerning the hazard
to humans from carbcfuran and its major alternatives. Based
on the available data/ carbofuran does not appear to pose
a chronic health hazard because it has not shown positive
oncogenic; tera tocer.ic, or reproductive effects. The data
base is complete and is considered acceptable. The data
bases for carbcfuran1s alternatives do not suggest adverse
health effects however the data ba.ses are net complete so a
full conclusion cannot be drawn. The Agency has required
that these data be submitted to complete the data bases.
Based on data on acute health effects, the acute oral
hazard cf carbcfuran is the same order cf magnitude as
foncphcs, phcrate, and terbufcs, but is less than aldicarb,
end greater than the other majcr alternatives.
Environmental Characteristics:
The Agency also evaluated the potential for ground
water contamination from carbofuran. The environmental
fate data indicate that carbcfuran is highly mobile and
has a potential to leach. Simulation modeling supports
this hypothesis. The environmental fate data indicate
that under conditions of low pH and low temperature/
residues of carbcfuran could persist after leaching intc
ground water. Since these conditions are not widespread
in the United States/ roost leaching of carbofuran will
probably not result in significant concentrations at the
wellhead. Monitoring information for Long Island/ New
York; Maryland: and* Massachusetts show the highest and
most frequently found residues in ground water. Concentra-
tions above 36 parts per billion/ the draft lifetime Health
Advisory Level/ will probably only occur in localized/
worst-case situations. The Agency will be requiring the
.registrants to revise the product labels' ground water
advisory statement.
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Ecological Effects:
To evaluate the avian hazard from the granular formu-
lation/ the Agency evaluated the risk to birds based on
(1) acute avian texicity, (2) exposure, (3) field studies,
(•4) bird kill incidents/ and (5) population effects.
Based on laboratory data/ the Agency concluded that
granular carbofuran is acutely toxic to birds/ and that
a single granule may kill a small bird. Birds are expected
to be present at the time of carbofuran application.
Dietary exposure occurs from direct .ingestion of granules
and exposure from ingestion of contaminated soil invertebrates
such as earthworms. Predatory birds may be secondarily
exposed to carbofuran by feeding on contaminated vertebrates
such as small birds.
There were 6 field studies conducted at 11 locations
that investigated the loss of birds from label-directed,
soil-incorporated uses of 10G and 15G applied as band
and in-furrow applications and 10G using specialized
equipment. All studies consistently resulted in bird
mortality, regardless of application rate or methods
which employed commonly practiced techniques for soil
incorporation of granules. Both direct and secondary
poisoning occurred.
Bird kill incidents from direct poisoning from carbofuran
granules have occurred in several crops in various areas
cf the country and Canada. The types of birds varied and
included both migratory and r.onr.igratory birds. Bird
mortality was frequently associated with at-planting
application, but has occurred with other uses throughout
the year. Direct poisoning of birds has caused over 40
reported bird kill incidents.
Secondary poisoning incidents have also occurred and
involved bald eagles/ red-tailed hawks/ red-shouldered hawks/
northern harriers/ and others.
The direct and secondary bird kill incidents that have
been reported underestimate the number of incidents actually
taking place because of the problems associated with the
reporting of bird kill incidents and with carcass removal
by predators.
Populations of declining or endangered species may
be present in areas where granular carbofuran is applied.
The Agency cited documented population declines of the
red-shouldered hawk/ loggerhead shrike* field sparrow*
Henslow's sparrow, and others. Statistically significant
declines have been measured for several species.
-------
While the Acer.cy does net consider granular carbe fur an
tc be the sole causative factor in the decline cf the cird
species discussed/ carbcfuran is one cf the most highly
toxic pesticides tc which these birds are exposed. Given
its widespread use in agriculture, cerbcfuran is likely
to be responsible for bird deaths in these species. The
Agency concluded that granular carbcfuran can/ therefore/
be an important additive factor in the declines.
The Fish and Wildlife Service's Division cf Endangered
Species and Habitat Conservation (DESHC) indicated in its
Biological Opinion for carbofuran that the Aplomado
falcon/ Attwater's greater prairie chicken/ and Aleutian
Canada goose were the bird species jeopardized by the use
of carbcfuran and indicated that the use be eliminated in
certain areas. DESHC also indicated that the bald eagle/
whooping crane/ and Mississippi sandhill crane may be
adversely affected. DESHC recommenced prohibiting the use
cf caroofuran in certain areas to avoid impact on these
spe ci es.
The Agency has examined other statutes that are intended
te prctect birds fine that .corr.pl iment' FIFRA. The Migratory
Eire Treaty Act prohibits the taking "by any means or in
any manner" individual birds of migratory species that are
listed in the Act's regulations. Birds cf mere than 20
sue.-; species have been reported killed by carbcfuran.
Likewise/ the Held and Golden Eagle Protection Act prohibits
takings of the bald and golden eagles and the Endangered
Species Act prohibits taking cf threatened or endangered
species. A number cf bald eagles killed by carbcfuran have
been reported and the Fish and Wildlife Service has determined
that carccfuran use threatens the continued existence cf
several endangered species.
The Agency has concluded that in general carbcfuran
poses the greatest risk to birds as compared with other
granular pesticides/ including its alternatives. This
conclusion was based on estimations of the numbers cf LDSOs
per square 'foot of treated ground according to labeled use
rates and methods.' The field studies and reported bird
kill incidents for carbofuran confirm the Agency's conclusion
that carbofuran poses a high risk. This approach for
comparative risk analysis can be used by the Agency to
identify other high risk pesticides for which regulatory
action would be appropriate.
BENEFITS ANALYSIS
The Agency analyzed the benefits of carbofuran use on
10 sites. The percentage of granular carbofuran use on
these sites is as follows: 68 percent for corn, 14 percent
for sorghum, 5 percent for soybeans, 2 percent for rice, 5
percent for peanuts, and 2 percent for tobacco. Also, less
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than 1 percent is used on each cf the following sites: cotter.,
cranberries/ sunflowers/ and pineseed orchards. These uses
encompass over 55 percent cf the granular carbcfuran usace
and about £5 percent cf all carbcfuran formulation usage.
If carbofuran is not available for treatment of the
10 sites/ the Agency estimated an annual grower impact
that ranged from approximately S22.B to S33.0 million.
The largest economic impact from cancellation of granular
carbcfuran will be for rice since no registered alternatives
are available for control of the rice water weevil. The
Agency estimates a grower impact to be S12.2 million
annually: a 56.1 million decrease in Federal deficiency
payments to rice crowers would indicate a loss to society
cf se.l million.
Corn is the major use site for carbcfuran/ and cost-
effective, efficacious alternatives are available. No
changes in costs of production/ yields/ or revenues are
expected. The corn insecticide market is highly competitive/
and viable alternatives with similar pesticide performance
are available at comparacie cost per acre.
The carbcfuran market for corn has been declining
since 1975, and current usage is approximately one-third
the level it was in 1S76. By 1°66, the market share held
by carccfuran dropped to less than 15 percent where/ in
terr.s of acre treatments/ it ranked fourth out of the five
major corn insecticides. The reasons for the decline are
not clear/ but could include loss in efficacy/ spectrum
cf centre!/ and ethers.
Carbcfuran is applied to nonflooded cranberries in
Washington and Oregon to control the black vine weevil.
Carbofuran is the only pesticide registered for black vine
weevil larvae control. Acephate is an efficacious insecticide
for control of the adults. The impact on cranberries/ without
considering acephate's use, is expected to occur over a
7-year period due to the perennial nature of the crop.
Overall impacts could range from §7 million to $7.7 million
over this period.
For the remaining crops, the Agency does not anti-
cipate major impacts. The overall economic impact from
cancellation is not expected to result in significant
changes in either production costs or outputs.
The Agency also evaluated aspects of carbofuran use
that are not easily quantifiable. For example, only one
carbamate (trimethacarb) would be available for corn
growers who rotate organophosphate and carbamate insecticides
to delay development of resistance in soil pests, although
the Agency recognizes that some cross-resistance with
organophosphates- could occur. Also, carbofuran has
-------
residual and systemic properties and a bread spectrum cf
control. However, repeated use of carbcfuran may lead tc
an apparent increase in scil micrecial populaticr.s t'r.at
are capable cf reducing its effectiveness.
SUMMARY OF REGULATORY POSITION AND RATIONALE
In weighing the risks and benefits, the Agency reviewed
a number of options ether than cancellation to reduce the
risk to birds. Among these measures were (1) additicnal
precautionary labeling regarding the hazard to birds/ (2)
limiting carbcfuran use to certain months cf the year/
(3) limiting application geographically i and (4) implemer. tine
a risk reduction program. The Agency evaluated these
measures and determined that they would net adequately
mitigate the risk.
As a result/ the Agency is proposing to cancel granular
carbcfuran use en ail sites. The decision to cancel
granular carbcfuran use is based en the conclusion that
the risk to birds outweighs the benefits cf use. Because
of the substantial risks and substantial benefits associated
with the use cf carbcfuran on rice to control the rice
water weevil, the Agency has requested specific additional
ir.fcrrr.aticn pertaining to the associated risks, benefits/
usace, and'additional means cf control.
Ci«^ »• ~- *
«.!.<*>
Jay Ilier.berger
Special Review Branch
Special Review and Reregistration Division
Office cf Pesticide Programs (TS-767C)
401 M Street/ S.W.
Kashincton, D.C. 20460
(703) 557-7400
DISCLAIMER: The information presented in this Pesticide Fac'
Sheet is for informational purpose only and may not be used
to fulfill data requirements for pesticide registration or
reregistration.
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United Stata Office of Penicioe and Toxic Substance! / ^ " f -^- / / tsflsb'
Environmental Protection OHice of Pejticid« Programj (TS-766C; (~ __^5—j^<~' v
Agency Washington. DC 20460 I ~——
* r— '• « "i •
&EPA Pesticide
Fact Sheet >»*. i a .337
Name of Chemical: CHLORDANE TOXICS ^ PESTICIDES
Reason for Issuance: REGISTRATION STANDARD BRANCH
Date Issued: DECEMBER, 1986
Fact Sheet Number: 109
DESCRIPTION OF CHEMICAL
Generic Name: 1 , 2,4,5,6,7,8 ,8-octachloro-2,3,3a,4,7,7a-
(Chemical) hexahydro-4,7-methanoindene
Common Name: Chlordane
Trade and 1,2,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-
Other 4,7-methanoindan; Velsicol 1068; Velsicol 168;
Names M-410; Belt; Chlor-Kil; Chlortox; Corodane; Gold
Crest C-100; Kilex; Gold Crest C-50; Kilex;
Kypchlor; Niran; Octachlor; Synchlor; Termi-Ded;
Topiclor 20; Chlordan; Prentox; and Penticklor
EPA Shaughnessy Code: 058201
Chemical Abstracts Service (CAS) Number: 57-47-9
Year of Initial Registration: 1948
Pesticide Type: Insecticide
Chemical Family: Chlorinated cyclodiene
U.S. and Foreign Producers: Velsicol Chemical Corporation
2. USE PATTERNS AND FORMULATIONS
Application Sites: subsurface soil treatment for termite
control; underground cables for termite
control; above ground structural
application for control of termites and
other wood-destroying insects
Types of Formulations: emulsifiable concentrates; granular;
soluble concentrates
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anc :-'e^;".3G£ cf Application: trenching, roccir.c, suirsl
injection, low pressure
spray for subsurface
termite control; brush,
spray, or dip for applying
to structural wood
Application Rates: 0.5 to 2.0% emulsion for termite control;
3.0 to 4.25% solution for above ground
structural wood treatment
3. SCIENCE FINDINGS
Summary Science Statement
Chlordane is a chlorinated cyclodiene with moderate acute
toxicity. The chemical has demonstrated adverse chronic
effects in mice (causing liver tumors). Chlordane may pose
a significant health risk of chronic liver effects to
occupants of structures treated with chlordane for
termite control. This risk may be determined to be of
regulatory concern, pending further evaluation. Chlordane
is highly toxic to aquatic organisms and birds. Chlordane
is persistent and bioaccumulates. Chlordane may have a
potential for contaminating surface water; thus, a
special study is required to delineate this potential.
Applicator exposure studies are required to determine
whether exposure to applicators may be posing health
risks. Special product-specific subacute inhalation
testing is required to evaluate the short-term respiratory
hazards to humans in structures treated with chlordane.
An inhalation study of one-year duration using rats is
required to assess potential hazards to humans in treated
residences from this route of exposure. The Agency has
been apprised of reported cases of optic neuritis
associated with termiticide treatment of homes. To
determine whether this is a significant health effect,
the registrant must have eye tissue from the latest
two-year rat oncogenicity study analyzed by neuro-
pathologists specializing in optic tissue pathology.
Data available to the Agency show an occurrence of misuse
and misapplication of chlordane. The Agency is requiring
restricted use classification of all end-use products
containing chlordane. Application must be made either
in the actual physical presence of a Certified Applicator,
or if the Certified Applicator is not physically present
at the site, each uncertified applicator must have
completed a State approved training course in termiticide
application meeting minimal EPA training requirements
-------
and be registered in the State in which the uncertified
applicator is working.
Chemical Characteristics of the Technical Material
Physical State: Crystalline solid
Color: White
Odor: Chlorine odor
Molecular weight and formula: 409.8 - CiQHeCls
Melting Point: 95 to 96°C
Boiling point: 118°C at 0.66 mmHg (technical)
Density: 1.59 - 1.63 at 25°C
Vapor Pressure: 0.00001 mmHg at 25°C (technical)
Solubility in various solvents: Miscible with aliphatic and
and aromatic hydrocarbon
solvents, including
deodorized kerosene;
insoluble in water
Stability: Loses its chlorine in presence of alkaline
reagents and should not be formulated with
any solvent, carrier, diluent or emulsifier
which has an alkaline reaction (technical)
Toxicology Characteristics
Acute Oral : Data gap
Acute Dermal: Data gap
Primary Dermal Irritation: Data gap
Primary Eye Irritation: Data gap (except for a 72% technical
formulation)
Skin Sensitization: Not a sensitizer.
Acute Inhalation: Data gap
Subchronic Inhalation (2-week duration) using rats or guinea
pigs: Data gap
Subchronic Inhalation (1-year duration) using rats: Data gap
Major routes of exposure: Inhalation exposure to occupants of
treated structures; dermal and
respiratory exposure to termiticide
applicators.
Delayed neurotoxicity: does not cause delayed neurotoxic
-------
effects.
C-p.coceni c i ty: This chemical is classified as a Group 63
oncogen (probable human oncogen).
There are three long-term careinogenesis
bioassays of chlordane in mice which were
independently conducted by investigators
affiliated with the National Cancer Institute,
the International Research and Development
Corporation, and the Research Institute for
Animal Science in Biochemistry and Toxicology,
Japan. Reported in these studies were signifi-
cant tumor responses in three different strain.
of mice (IRC, CF}_, and B6C3F^ ) in males and
females with a dose-related increase in the
proportion of tumors that were malignant. In
Fischer 344 rats, significant tumor responses
were reported in a study conducted by the
Research Institute for Animal Science in
Biochemistry and Toxicology.
Chronic Feeding: Based on a rat chronic feeding study with
chlordane, a Lowest Effect Level (LEL) of
0.05 mg/kg/day for liver effects
has been calculated. ,
Metabolism: Chlordane "s major metabolite is oxychlordane .
Oxychlordane has been found to be a major fat
tissue residue in rats. Human fat samples
frequently contain trans-nonachlor, a
contaminant found in technical chlordane, as
a major residue.
Teratogenicity: Data gap
Reproduction: Data gap
Mutagenicity: Data gap. Further testing is required in all
three categories (gene mutation, structural
chromosome aberrations and other genotoxic
effects.
Physiological and Biochemical Characteristics
The precise mode of action in biological systems is not
known. In humans, signs of acute intoxication are primar-
ily related to the central nervous system (CNS), including
-------
hvoerexcitaciltv/ convulsions, depression and c e a1 n .
Er.vi rcr.rrent a 1 Characteristic:
Available data are insufficient to fully assess the environ-
mental fate of chlorcane. Data gaps exist for all applicable
studies. However, available supplementary data indicate
general trends of chlorcane behavior in the environment.
Chlordane is persistent and bioaccumulates. Chlordane is not
expected to leach, since it is insoluble in water and
should adsorb to the soil surface; thus it should not reach
underground aquifers. However, additional data are necessary
to fully assess the potential for ground-water contamination
as a result of the termiticide use of chlordane.
Ecological Characteristics
Avian acute toxicity: LD5Q of 83.0 mg/kg in bobwhite quail
Avian dietary toxicity: 858 ppm in mallard duck; 331 ppm in
(8 day) bobwhite quail; and 430 ppm in pheasant.
Freshwater fish acute toxicity: 57 to 74.8 ug/L for bluegill;
(96 Hr. LCso) 42 to 90 ug/L for rainbow trout.
Freshwater invertebrate toxicity: 15 to 590 ug/L for Pteronarcys
(48 hr. and 96 hr. £€50) and Daphnia, respectively.
4. Required Unique Labeling and Regulatory Position Summary
0 EPA is currently evaluating the potential human
health risks of 1) non-oncogenic chronic liver effects, and 2)
oncogenic effects to determine whether additional regulatory
action on chlordane may be warranted.
0 In order to meet the statutory standard for continued
registration, retail sale and use of all end-use products
containing chlordane must be restricted to Certified Applicators
or persons under their direct supervis ..on. For purposes of
chlordane use, direct supervision by a Certified Applicator means
1) the actual physical presence of a Certified Applicator at the
application site during application, or 2) if the Certified
Applicator is not physically present at the site, each
uncertified applicator must have completed a State approved
training course in termiticide application meeting minimal EPA
training requirements and be registered in the State in which the
uncertified applicator is working; the Certified Applicator must
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- 1 .-: ~rcer to r.eet the statutory standard tor
rec i s tr a t i err: , chlorcar.e product laoels rr.usc oe revised to prcvi
specific chlcrdane disposal procedures, and to provide fish and
wildlife t o x i c i t y warnings.
c The Agency is requiring a special monitoring study
to evaluate whether and to what extent surface water contam-
ination may be resulting from the use of chlordane as a
termiticide.
0 Special product-specific subacute inhalation testing
is required to evaluate the respiratory hazards to humans in
structures treated with termiticide products containing
chlordane .
0 Evaluation of eye tissue from the latest
two-year rat oncogenicity study is required to determine
whether chlordane 's termiticide use may be causing optic
neuritis in humans.
0 The Agency is requiring the submission of applicator
exposure data from dermal and respiratory routes of exposure.
0 While data caps are being filled, currently registerd
manufacturing use products and end use products containg chlord
may be sold, distributed, formulated, and used, subject to the
terms and conditions specified in the Registration Standard
for chlordane, and any additional regulatory action taken by
the Agency. Registrants must provide or agree to develop
additional data in order to maintain existing registrations.
5. TOLERANCE REASSESSMENT
No tolerance reassessment for chlordane is necessary, since
there are no food or feed uses. The Agency is proceeding
to revoke all tolerances and replace them with action levels
The final rule is scheduled for publication in the Federal
Register in early 1987.
6. SUMMARY OF MAJOR DATA GAPS
o
Hydrolysis
0 Photodegradation in Water
0 Aerobic Soil Metabolism
Anaerobic Soil Metabolism
o
-------
• Leacrir.c: ar.; .~.cs crpt icn •• Desorpt ior.
0 Aerocic Acua.ic Metaoolisr.
5 Soi1 Dissipation
0 Chronic Toxicity Studies- Rodents and Non-rodents
r- Teratogen i ci ty
0 Mutagenicity Studies
0 Acute Toxicity Studies
0 Optic Tissue Pathology
c Special Surface Water Monitoring Studies
0 Applicator Exposure Studies
° Indoor Air Exposure Studies
0 Special Product-Specific Subchronic Inhalation Study
(two-week duration using guinea pigs or rats)
0 Subchronic Inhalation Study (One-year duration using rats
0 All Product Chemistry Studies
7. CONTACT PERSON AT EPA
George LaRocca
Product Manager (15)
Insect icide-Rodent icicle Branch
Registration Division (TS-767C)
Office of Pesticide Programs
Environmental Protection Agency
401 M Street, S. W.
Washington, D. C. 20460
Office location and telephone number:
Room 204, Crystal Mall 12
1921 Jefferson Davis Highway
Arlington, VA 22202
(703) 557-2-*fr6 3*100
DISCLAIMER: The information presented in this Chemical Information
Fact Sheet is for informational purposes only and may not be used
to fulfill data requirements for pesticide registration and
reregistrat ion .
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Unh«5 Sort* CHltt of P«rtioo- ind Toiie Sub*tinc«
Ermronm«nai Pn>r»C(or, Otlict of Ponoot Proqnm. (TS-76SC:
n, CC »
&EPA Pesticide -
Fact Sheet
Name of Chemical: 2,4-0
Reason for ISSUanCS: Proposed Decision Not tc Initiate
Date ISSUed: March, 1988 Special Revie;
Fact Sheet Number:
DESCRIPTION 0? CHEMICAL
Generic Name: (2,4-Dichlorophenoxy) acetic acid
Common Name: 2,4-D (includes parent acid as well
as 35 ester and salt derivatives)
EPA Shaughnessy Code: 030001
Chemical Abstracts Service (CAS) number: 94-75-7
Year of Initial Registration: 1948
pesticide Type: Herbicide, plant growth regulator
Chemical Family: Chlorinated phenoxys
USE PATTERNS AND FORMULATIONS
2,4-D is a systemic herbicide widely used to control
broadleaf weeds. Over 1500 registered pesticide products
contain 2,4-D as an active ingredient. Approximately
60 million pounds of 2,4-D (as active ingredient) are
applied annually in the U.S. The majority is used to
control broadleaf weeds in wheat, field corn, grain
sorghum, sugar cane, rice, barley, range and pastureland.
Use Patterns:
Agricultural - Wheat, field corn, grain sorghum, sugar
cane, rice, barley, soybeans, orchard crops.
Aquatic Management - Water hyacinth and Eurasian
watermilfoil control in lakes and ponds where treated
water is not used for domestic or irrigation purposes.
Pasture and Ranqeland •.- Brush control..
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Hc~e ar.c Garden - Lawns, ornamental, turf, parks,
recreation areas.
Forest Management - Brush control, conifer release, tree
injection.
Types and methods of application:
Aerial and ground equipment, knapsack sprayers, pressure
and hose-end applicators, and lawn spreaders.
Types of formulations:
Granular, atnine and ester liquids, dust, end aerosol
spray (foam).
SCIENCE FINDINGS
Tolerance Assessment:
Tolerances are established for residues of 2,4-D acid in
a variety of raw agricultural commodities, as well as
meat, milk, eggs, poultry, fish and shellfish. The
tolerances, listed in 40 CFR 180.142, include residues
of 2,4-D resulting from the application of the acid,
salt and ester forms..
Food additive tolerances have been established for
sugarcane molasses, milled fractions from barley, oats,
rye, wheat, and potable water (from 2,4-D use in specific
aquatic management programs).
Toxicology Summary:
Teratology Data (birth defects) - The parent acid and
ester form were tested for their ability to induce birth
defects in Fischer 344 rats by oral gavage. The parent
acid form did not indicate a teratogenic effect up to 75
mg/kg/day (fetotoxic NOEL = 25 mg/kg/day). The ester
form (2,4-dichlorophenol) did not indicate any teratogenic
effect (fetotoxic NOEL = 375 tngAg/day) .
Reproduction Data - The parent acid was fed to Fischer.
344 rats to measure the effect on the reproduction
system. At the lowest dose tested (5 mg/kg/day), neither
parent nor offspring were affected by the administration
of 2,4-D. At the next higher dose (20 mg/kg/dayV, a
decrease in maternal body weight and pup weight was
observed.
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N e u r o t o x i c i t v Data - The dimethylamine salt of 2,4-D
was repeatedly applied dermally (skin) to Fischer CDF
344 rats to determine if such exposure on the peripheral
nervous system would produce pharmacological and/or
toxicological effects. No treatment-related changes in
the function or structure of the nervous system were
observed, although a decrease in total animal and kidney
weight was noted.
Carcir.ocenicity Data - In separata studies, the parent
acid was fed to rats (CDF(F344)/Crl-3r) and mice (BgCiri
Crl-3r) for 2 years to determine the carcinogenic potential
of 2,4-D. The rat study found a marginally statistically
significant trend for astrocytomas (brain tumors) based
on an increased incidence of these tumors in male animals
at the high dose group. The mouse study found no carcinogenic
response. However, the rat study provides inadequate
evidence of carcinogenicity in laboratory animals.
Eoidemioloaical Data - A number of studies have been
conducted to determine whether 2,4-D produces cancer in
h'umans. A study conducted in Kansas found an apparent
association between non-Hodgkin1s lymphoma and farmers
who used phenoxy herbicides, including 2,4-D, but found
no association between soft-tissue sarcoma and Hodgkin's
disease and the same farmers. The Agency has determined
that this study, based on bias and confounding factors,
is inadequate for assessing 2,4-D's carcinogenic potential.
Another study conducted in Western Washington found no
association between non-Hodgkin1s lymphoma or soft-tissue
sarcoma and farmers specifically handling 2,4-D. Including
other studies, the available epidemiological evidence
is not adequate for classifying or regulating 2,4-D as
a carcinogen.
4. SUMMARY OF PROPOSED REGULATORY DECISION
Pursuant to Special Review procedures, preliminary
notifications were sent on September 22, 1986 to registrants
of 2,4-D and on December 3, 1935 to registrants of 2,4-DB
and 2,4-DP (structural relatives of 2,4-D), informing
them that the Agency was considering initiating a Special
Review based on the new epidemiologic evidence.
Following a review of comments received on the preliminary
notifications and a more thorough analysis of all available
data, the Agency is proposing not to initiate a Special
Review of 2,4-D, 2,4-DB and 2,4-DP at this time. This
decison is based on a consensus of opinion from EPA
scientists, epidemiological experts, and the FIFRA
Scien ific Advisory Panel that existing epidemiologic
evidc .ce is inadequate to regulate 2,4-D as a carcinogen.
-------
Michael McDavit
Review Manager
Special Review Branch
Registration Division
Office of Pesticide Proarams
(702) 557-1787
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TKZ EBDC PESTICIDES
AND EPA'S PROPOSED REGULATORY DECISION
Facts for Consumers
One of the Federal government's and the Administration's
highest priorities is food safety. EPA, FDA and USDA share the
goal of ensuring public health, environmental protection, and a
safe and abundant food supply. President Bush recently announced
his Food Safety Plan, a comprehensive new program involving the
three agencies which will enhance food safety for all Americans.
The United States' food supply is among the safest, most
plentiful, and most affordable in the world. Agricultural
pesticides play an important role in the production of the foods
we all enjoy and depend upon for good health. It is important to
recognize that all pesticides are inherently toxic to something—
none are completely risk-free. Still, it is also important to
remember the basic rule of science that "the dose makes the
poison." In other words, too much of anything can be harmful. For
this reason, EPA, FDA and USDA set standards for pesticide residues
in food and monitor the U.S. food supply to ensure that safety
standards are met.
There are ns documented cases of cancer or other serious long-
term health effects resulting from exposure to pesticide residues
in food. Fresh fruits and vegetables are an essential part of a
healthful diet. A recent study by the National Academy of Sciences
-------
emphasizes that Americans should increase the amount of fresh
fruits and vegetables consumed. The study went on to say that
foods containing low levels of pesticide residues do not present
a significant health risk.
In regulating pesticides, EPA evaluates the potential dietary
•
risks from pesticides and manages those risks by setting standards
for allowable residue levels far below the point at which a
theoretical risk exists. Remember: the dose makes the poison.
Through this process of risk management, EPA seeks to ensure that
the benefits of a safe and abundant food supply will continue to
be realized for all American consumers.
Ql. What are the EBDCs?
The EBDCs—mancozeb, maneb, metiram and nabam—are a group of
pesticides used to control fungi, primarily on a wide variety
of fruits, vegetables, ornamental plants, and on turf grass.
EBDC fungicides are used in commercial agriculture, in some
industrial processes such as making paper, and on home lawns
and gardens.
The EBDCs used in agriculture protect food crops against
damage by mold, mildew and fungal diseases. The EBDCs help
ensure the continued availability of a plentiful, varied, low
cost, high quality food supply.
-------
Q2. What riBk.6 do the EBDCs pose?
The EBDC fungicides break down into ETU (ethylenethiourea),
a metabolite common to all EBDCs. Laboratory animals have
developed cancer, thyroid disorders and birth defects after
being exposed to ETU. It is theoretically possible that if
•
people ate foods containing the maximum legal EBDC residues
throughout their lifetimes, their risk of getting cancer might
be slightly higher than the existing background cancer risk
of one in four for the general population.
Similarly, people who handle or apply EBDC fungicides without
wearing protective clothing may slightly increase their risk
of developing cancer or thyroid problems, or of having
children with birth defects.
Q3. What do you mean by saying it is "theoretically possible" for
the EBDCs to cause cancer? Doesn't EPA know for sure?
In assessing the risks of any pesticide, EPA uses laboratory
animal data to learn about possible adverse health effects in
people. However, considerable uncertainty is involved in
extrapolating laboratory data from test animals to humans.
To make up for this uncertainty, EPA uses a number of very
cautious assumptions and procedures in its risk assessment
process.
-------
For example, one standard assumption is that consumers are
exposed to a pesticide throughout their entire lifetimes,
estimated to be about 70 years long. Another assumption is
that 100 percent of crops that may legally be treated with a
pesticide are in fact treated with that pesticide. A third
assumption is that pesticide residues are always present in
<
food items at maximum legal levels when they are consumed.
In reality, people are almost never exposed to residues of any
one pesticide throughout their entire lives; only a portion
of crops are treated; and pesticide residues tend to break
down in foods by the time foods reach the consumer.
EPA's risk estimates for the EBDCs probably are higher than
the actual risks posed, because we used the assumptions just
described. The Agency is in the process of getting more
information and study results about the EBDCs, which will help
refine our current risk estimates. Rather than waiting for
this new information, however, EPA is proposing a regulatory
decision now, even though there are still many unknowns. By
doing this, we can move quickly when the new data arrive.
Q4. Can EBDC residues be removed from fruits and vegetables? How
can I reduce my exposure to the EBDCs in foods?
EBDC residues decline rapidly in fruits and vegetables after
these fungicides are used on the farm. Remaining residues of
the EBDCs are found primarily on the surface of fruits and
-------
vegetables. You can reduce your exposure to the EBDCs by
removing these surface residues before cooking or eating
produce. Wash fresh fruits and vegetables with water, and
peel them or scrub them with a brush, as appropriate. Throw
away the outer leaves of leafy vegetables such as lettuce and
cabbage unless such trimming has already been done by your
•
grocer.
Q5. What happens when you cook produce that contains residues of
the EBDCs? What effect does cooking or processing have on
EBDC residues in fruits and vegetables?
The best way to minimize exposure to the EBDCs and ETU is by
washing and, if possible, scrubbing and peeling fresh fruits
and vegetables to remove as much surface pesticide residue as
possible before cooking or eating these foods.
Cooking or processing most fruits and vegetables containing
EBDC residues increases the amount of ETU in the food. This
is because a portion of the EBDCs is converted to ETU through
heating. EBDCs also are converted to ETU within the human
body through metabolic processes, such as digestion.
Therefore, you cannot avoid exposure, to ETU by eating raw
rather than cooked or processed fruits and vegetables.
Q6. Is it safe for babies and children to eat fruit and vegetables
that contain EBDC residues?
-------
Yes, in evaluating the lifetime risk of eating foods that
contain residues of the EBDCs, EPA has taken into account the
special eating habits of children. We have assumed that
infants and children eat proportionately greater amounts of
certain foods than adults do. Parents may be assured,
«
therefore, that their children are not at particular risk from
dietary exposure to the EBDCs.
Q7. Do imported foods also contain EBDC residues? How is the
Federal government ensuring the safety of imported foods
containing residues of the EBDCs?
Imported foods may contain EBDC residues but these residues
are the same as the legal limits, or tolerances, that EPA sets
for domestic produce. Imported food shipments are routinely
monitored by the Food and Drug Administration (FDA) for
compliance with U.S. tolerances, and shipments that do not
comply with our tolerance requirements may be refused entry
into this country. Once EPA cancels a number of EBDC food
crop uses, the Agency also will revoke the corresponding
tolerances. Imported foods will not bring the EBDCs back into
the diet of the American consumer.
Q8. What is EPA doing about the EBDCs?
Based on an intensive risk/benefit review, EPA is proposing
-------
to cancel, or permanently stop, 42 of the 55 current
agricultural crop uses of the EBDCs. EPA's action will reduce
the theoretical long-term dietary risk of cancer posed by the
EBDCs, and thus will ensure the continued safety of the U.S.
food supply.
*
EPA also is requiring the manufacturers of the EBDCs to
conduct a market basket survey, measuring residues of EBDCs
and ETU that actually remain in fresh, canned and frozen foods
as they are sold in grocery stores. The resulting information
on actual dietary exposure to the EBDCs will be an essential
part of EPA's risk assessment and final regulatory decision
on these fungicides.
EPA also is proposing to require that workers wear protective
clothing when handling and applying the EBDCs, to guard
against an increased risk of cancer, thyroid problems and
birth defects.
Q9. If eating foods treated with EBDCs may be dangerous, why
doesn't EPA take all EBDC food uses off the market,
immediately?
EPA is not taking action to immediately halt all uses of the
EBDCs because we do not believe that American consumers face
imminent danger from consuming foods treated with these
fungicides. The theoretical risks posed by the EBDCs are
-------
long-tent cancer hazards, not short-term risks requiring
immediate action. In addition, voluntary action by three of
the major manufacturers of the EBDCs will remove many uses of
these fungicides during the next several years, reducing
consumers' exposure until EPA has sufficient data on which to
base a final regulatory decision.
•
Further, EPA should not take mil EBDC food crop uses off the
market because all do not pose unacceptable long-term risks.
The risks posed by different EBDC crop uses vary because of
differences in agricultural practices among crops, variations
in the handling, processing and preparation of different
foods, and varying contributions of foods to the typical
American diet. After analyzing the risks and benefits of each
of the current EBDC food crop uses, EPA is proposing to canc
those that we believe pose unacceptable long-term hazards.
Q10. To be on the safe side, should I stop eating fruits and
vegetables that may be treated with the EBDCs until EPA makes
a final cancellation decision?
No, you may safely continue to eat fruits and vegetables
during the next two years, while EPA completes the process of
cancelling nost uses of the EBDCs. In the interim, three
major manufacturers of the EBDCs have volunteered to remove
many agricultural uses from their product labels. Since use
of the EBDCs on food crops will significantly decrease
-------
the next meverai years, the incremental risk to consumers will
be negligible.
As emphasized in a report issued earlier this year by the
National Academy of Sciences, fresh fruits and vegetables are
a vital part of a well-balanced, healthy diet. The benefits
*
to good health of eating a variety of fresh fruits and
vegetables far outweigh the theoretical risks of consuming
minute quantities of pesticide residues on these foods.
Qll. Even if certain uses of the EBDCs are safe enough to remain
on the market, isn't it dangerous to eat a diet that consists
of many or all of these retained, EBDC-treated foods? In
other words, is it safe to eat the salad bar?
Yes, it is safe to eat many foods at once that have been
treated with EBDCs. In evaluating these food crop uses, EPA
has considered not only their individual risks but also the
combined effects of eating all of them. We believe that, over
a lifetime, it would not be prudent for consumers to continue
to eat all the foods currently containing residues of the
EBDCs. But, by eliminating uses that pose the greatest risks,
EPA will ensure that consumers can safely eat the .remaining
EBDC-treated food crops throughout their lives.
Q12. How much of the EBDCs remain on the food we eat?
-------
To evaluate consuaers' exposure to the EBDCs, EPA used field
studies which show the highest levels of these fungicides that
may legally remain on treated crops as they leave the fare.
However, other evider :e suggests that EBDC residues on treated
food crops decline rapidly, and can be further reduced by
washing, peeling and trimming produce. EPA needs and is
«
regxiiring the EBDC manufacturers to conduct a well-designed
market basket study showing actual EBDC residue levels
remaining on treated food crops when they are sold in grocery
stores. We expect that the actual residue levels in fruits
and vegetables on the "dinner plate" will prove to be much
lower than those found at the "farm gate."
The Food and Drug Administration (FDA) also is conducting a
special study to determine levels of the EBDC metabolite ETU
in the American diet. The results of these studies will be
available by the fall of 1990.
Q13. How do the EBDCs compare with Alar?
(
The EBDCs are different from Alar in several respects. Alar
cannot be removed from treated produce by washing or peeling;
EBDC residues concentrate on the surface of treated food crops
and residues oan be reduced by washing and, if possible,
peeling produce. In addition, EBDC and ETU residues degrade
more rapidly than those of Alar and its metabolite UDKH, so
very low levels of EBDCs and ETU are likely to remain on
-------
Q15. Hov can I safely dispose ot unused, unwanted EBDC home lavn
and garden products?
The safest and most environmentally sound way to dispose of
excess amounts of the EBDCs is to use them, in accordance with
their label directions and precautions. As an alternative,
*
store these pesticides securely, out of children's reach,
until you have an opportunity to dispose of them through a
county, city or other local household hazardous waste
collection program. If such a program is not available in
your area, investigate other local disposal possibilities.
You may be allowed to dispose of unused EBDC pesticides
through your regular trash collection service. Wrap each
product container in several layers of newspapers, tie
securely, and place the package in a covered trash can for
routine collection with municipal refuse. If you do not have
a regular trash collection service, you may be allowed to
dispose of EBDC products in a permitted landfill, depending
on the quantity and formulation of the pesticide that you have
on hand, and depending on your State, county and local waste
disposal requirements.
Check with your State or county waste management agency or
with the RCRA program in your U.S. EPA Regional Office before
disposing of excess or unwanted EBDC pesticides.
-------
For additional information on the EBDCs, call the National
Pesticides Telecommunication Network toll-free at 1-800-858-7378,
or contact your U.S. EPA Regional Office.
[List Regional offices with telephone numbers and list of
«
states they serve.]
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&EPA Pesticide
Fact Sheet
540/F£-r9-052
HEPTACKLOR
M*r«« ~( rhamiral- PROHIBITION OP CONTINUED SALE
Name of Chemical. OR USE op ^^cm)R PRODUCTS
Reason for Issuance: FOR SEED TREATMENT
Date issued: APR 26 ,939
Fact Sheet Number: 107.2
1. DESCRIPTION OF CHEMICAL
Generic Name: l,4,5,6,7,8-8-heptachloro-3a,4,7,7a-tetra-
(Chemical) hydro-4,7-methano-lH indene
Common Name: Heptachlor
Trade and Other Names: l,4,5,6,7,8,8-heptachlor-3a,4,7,7a-
tetrahydro-4,7-methanoindene; E-3314; Velsicol 104.
EPA Shaughnessy Code : 044801
Chemical Abstracts Service (CAS) Number: 76-44-8
Year of Initial Registration: 1952
Pesticide Type: Insecticide
Chemical Family: Chlorinated cyclodiene
2. USE PATTERN - SEED TREATMENTS
ACTION: Notice of PROHIBITION OF'CONTINUED SALE OR USE OF HEPTACHLOR
PRODUCTS FOR SEED TREATMENT.
The Administrator has signed a Notice of Determination Pursuant to
Section 6(a)(l) of FTPRA which will be published in the Federal
Register. The Notice will prohibit any further sale or use of
heptachlor products for seed treatment purposes. Any sale or use of
heptachlor products for seed treatment will be a violation of Section
12(a)(l)(A) and/or Section 12(a)(2)(K) of the Federal Insecticide,
Fungicide and Rodentlclde Act (FIFRA).
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3. REGULATORY HISTORY
A. NOTICE OF INTENT TO CANCEL
Prior to .1974, heptachlor (along with a related compound, chlordane) was
registered for a wide variety of Insecticide uses. On November 18, 1974,
the Administrator Issued a notice of Intent to cancel registrations for
most uses of heptachlor (and chlordane). The basis for the notice of
Intent to cancel was evidence that heptachlor and chlordane had demonstrated
toxic effects which may have significant adverse effects on human health,
and evidence that both chemicals persist in the envlrcnnent for many
years after application, and as such, are subject to considerable movement
from the site of actual application. The evidence on toxicity Included
a finding that heptachlor and its metabolite, heptachlor epoxide Induce
tumors In mice and that there was evidence of embryotoxlcity in mice and
rats.
Because of the persistence and wide application of heptachlor and chlordane
products, heptachlor epoxide residues were routinely found in water, food
sources, and human adult and fetal tissue. The Administrator therefore
proposed to cancel all registered uses of chlordane and heptachlor, except
those uses for subterranean termiticide control (see note) and dipping of
non-food plants.
NOTE: It should be noted that subsequently on October 1, 1987, EPA
issued an Order accepting the voluntary cancellation of
chlordane and heptachlor teraitlcide treatment products. A
Notice signed on April 5, 1988, in response to a District Court
ruling established limits on the sale and use of existing stock
of teraiticlde products after April 15, 1988.
B. THE SUSPENSION OF HEPTACHLOR PRODUCTS
On July 29, 1975, the Administrator issued a notice of Intent to suspend
(pursuant to FIFRA Section 6(c)) the registrations of heptachlor and
chlordane that were subject to the notice of Intent to cancel. The
grounds for the notice of Intent to suspend were "new evidence ... which
confirm [ed] and heighten [ed] the human cancer hazard posed by [chlordane
and heptachlor]" and the Administrator's determination that the cancellation
proceeding resulting from the notice of Intent to cancel would not be
complete [ed] in time to "avert substantial additions of these persistent
and ubiquitous compounds to an already serious human and environmental
burden." The notice of Intent to suspend applied to all uses covered by
the notice of Intent to cancel.
An evidentiary hearing on the proposed suspension took place between
August and December of 1975. On December 12, 1975* the hearing examiner
published a recommended decision dismissing the notice of Intent to suspend.
The basis for this recommendation was the hearing examiner's unwillingness
to find "conclusively" that heptachlor and chlordane were (are) carcinogens
in laboratory animals.
-------
Included in the recccmended decision was a discussion of the use of
heptachlor for seed treatment. The document noted that inadequate
alternatives for seed treatment existed at that time. The hearing examiner
recommended that heptachlor Tor seed treatment not be suspended even if
the Administrator were to disagree with the examiner on the question of
the hazard posed by chlordane and heptachlor.
On December 24, 1975, the Administrator issued his decision on the proposed
suspension of chlordane and heptachlor products. The Administrator
ordered a suspension of a number of chlordane and heptachlor uses during
the pendency of the cancellation hearing.
As to seed treatment, however, the Administrator found that no adequate
alternatives to treatment with heptachlor existed at that time, and
therefore found that the benefit from heptachlor for seed treatment
exceeded the risks of such use during the time necessary to complete the
cancellation hearing. Heptachlor for seed treatment was thus not one of
the uses suspended by the Administrator.
C. SETTLEMENT OP THE CANCELLATION PROCEEDING
Ihe cancellation proceeding continued until November of 1977, at which
time the parties entered into settlement negotiations. The negotiations
resulted in an agreauent which was ratified in a Final Order issued by
the Administrator on March 6, 1978. The Final Order resulted In the eventual
cancellation of all products subject to the original notice of Intent to
cancel notice. For seed treatment, the effective date of cancellation was
September 1, 1982 for barley, oats, wheat, rye and corn, and July 1, 1983
for sorghum. The Order also contained production limitations; production
of heptachlor for seed treatment was limited to 175,000 pounds annually
from 1978 to 1982, and to 100,000 pounds In 1983. These production
limitations were intentionally less than the use of heptachlor for seed
treatment purposes in 1976 (which was 200,000 pounds).
The purpose of the phased cancellations was to provide a "transition
period" to allow users to make an orderly adjustment to alternative crops
or pest control technologies where possible or to promote development of
alternative pest control technologies where none then existed.
D. EXISTING STOCKS DETERMINATION
The sale and use of existing stocks of pesticide products cancelled after
a notice of intent to cancel is issued pursuant to Section 6(b) of PIFRA
are controlled by Section 6(«&(1) of FIPRA. It provides In part,"... the
Administrator may permit the continued sale and use of existing stocks of
a pesticide whose registration is canceled under [Section 6(b)] to such
extent as he may specify If he determines that such sale or use is not
inconsistent with the purposes of [PIFRA] and will not have unreasonable
adverse effects on the environment."
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At the tine the Agency issued the Final Order, it was expected based
upon the use practices at that tirae that sale and use of existing stocks
of cancelled products would cease approximately within one year of the
effective cancellation date. The existing stocks allowance and phased
cancellation was to result in approximately a six year transition period
for users of heptachlor treated seeds to adapt alternative management
practices after 1978.
The six year transitional period contemplated in 1984 ended over four
years ago. The Agency believes that ten years Is more than sufficient
time for users to find alternatives to heptachlor seed treatment.
Moreover, although some heptachlor continues to be used for seed treatment
purposes, the transition away from heptachlor seed treatment has largely
been completed (the amount of heptachlor used for seed treatment in 1987
was only 1% of the amount used in 197^).
While the benefits associated with heptachlor seed treatment have greatly
diminished in the past ten years, the Agency's general concerns with the
use of heptachlor have not diminished.
In addition, in late January and early February of 1986, the Food and Drug
Administration (FDA) found very high levels of heptachlor and trans-chlordane
in finished livestock feeds.
A fermentation/distillation firm purchased and used obsolete pesticide
treated seed grain in their fermentation process. The spent distillers
mash was, in turn, used In the manufacture of finished animal feeds and
fed to dairy cattle. When FDA tested the milk from dairy herds fed the
contaminated feed, the levels of heptachlor epoxlde (an animal metobolite
of heptachlor) found exceeded, by as much as 75 times, the FDA action
level of 0.1 ppm for heptachlor epoxlde in the milk fat.
As the result of this one incident, taxpayers have already Incurred more
than ten million dollars In Investigative and Indemnification costs.
Total losses for all affected parties are expected to exceed sixteen million
dollars.
FDA and USDA subsequently carried out an extensive investigation to
determine how frequently obsolete pesticide treated seeds were being fed
illegally to meat and/or milk producing animals or had entered the livestock
feed markets. In over 1000 investigations, well over 100 violations were
found. Feeding of obsolete heptachlor treated seed was Involved in at
least two of these additional violations.
EPA subsequently has determined that sizable inventories of cancelled
heptachlor seed treatment products remain in the channels of trade. At the
present levels of use, these products would be available for use for the
next 70 years.
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As previously stated, under Sec tier, fc { a) ( 1 .'• , the Acer. :y rcey perrr.it the
continued siie and use cf existing stocks cf a cancelled pesticide only
if the Acency detenr.ines that such sale and use is consistent with FIFRA
and does not result in unreasonable adverse effects on the environment.
Under the circumstances, the Agency can no longer find that continued
sale or use of heptachlor for seed treatment will not have an unreasonable
adverse effect on the environment. The Agency therefore no longer believes
that such sale or use is consistent with Section 6(a)(l) of FIFRA.
The Agency accordingly served notice in the Federal Register of
that sale or use of stocks of heptachlor for seed treatment is no longer
permitted, and that any further sale or use shall be a violation of Section
!2(a)(l)(A) and/or Section 12(a)(2)(K) of FIFRA.
While any further use of heptachlor for seed treatment is not permitted,
existing stocks of seed grain previously treated with heptachlor may be
sold and planted in accordance with good agronomic practices.
4. GUIDANCE ON THE STATUS OF HEPTACHLOR SEED TREATMENT PRODUCTS AS
HAZARDOUS WASTES
Unused quantities of cancelled heptachlor seed treatment products can
. o longer be used as directed on their label. They, therefore, fit the
.•finition of a solid waste as defined in 40 CFR 261.2 and 261.33 when
chey are discarded or held with the intent to discard.
A hazardous waste is any solid waste which has been listed as a hazardous
waste in 40 CFR Part 261 Subpart D or a solid waste which exhibits any of
the characteristics of hazardous waste identified in 40 CFR Part 261
Subpart C ignitability, §261.21; corrosivity, §261.22; reactivity,
§261.23; and/or E.P. toxicity, §261.24.
Heptachlor is listed as an acutely hazardous waste (P059) in 40 CFR
§26l.33(e). Any unused heptachlor seed treatment products, rinsate or
containers which have not been properly cleaned (triple rinsed as defined
§261.7) are therefore acutely hazardous wastes, as defined in 40 CFR
§261.33(e) if they are discarded or intended for discard.
Any person by site who holds cancelled heptachlor seed treatment products
when they become wastes is a "generator" of hazardous wastes as defined
in 40 CFR Part 261. A generator must comply with the requirements of
the Resource Conservation and Recovery Act (RCRA) and any other applicable
Federal, State, and local laws and regulations.
Those who hold cancelled heptachlor seed treatment products at the time they
become wastes are defined as "generators" and they fall into one of three
categories of waste generators. They are:
a. Conditionally Exempt Generator - one who currently holds or
generates no more than 1 kilogram (2.2 pounds) of acutely
-------
hazardous waste t heptachlcr seed treatment products, a listed
acutely hazardous waste (?059)] and who generates no more than
100 kilograms (220 pounds) of other hazardous waste in any
calendar month.
A conditionally exempt generator is not required to obtain
a permit or interim status (40 CFR Part 261.5). He/she, however,
is required to:
* Identify all hazardous waste held or generated, §261.5(c).
* Send the hazardous waste to an authorized facility,
§261.5(f)(3).
" Never accumulate more than 1000 kilograms (2200 pounds)
of hazardous waste and/or more than 1 kilogram (2.2
pounds) of acutelv hazardous waste on his/her property,
§261.5(f)(2) and '( g ) ( 2 ) .
Acutely hazardous waste (PO59) may be held [up to 1 kilogram
(2.2 pounds)] in containers which are in good condition (do not
leak) and are compatible with the waste.
Small Quantity Generator - one who holds or generates no more than .'
kilogram (2.2 pounds) of acutely hazardous waste [heptachlor seed
treatment products, a listed acutely hazardous waste (PO59)] and
generates between 100 and 1,000 kilograms (220 to 2,200 pounds) of
other hazardous waste in any calendar month.
A small quantity generator must comply with the requirements
of 40 CFR Part 262, Standards Applicable to Generators of Hazardous
Waste including obtaining an EPA ID number, using the Uniform
Hazardous Waste Manifest, accumulating waste in accordance with
§ 262.34(d) and complying with recordkeeping.and reporting
requirements of §262.40(a), (c) and (d); § 262.42(b);. and
§262.43 .
Small quantity generators who choose to store or treat beyond
the allowances provided in 262.34(d)-(f) or to dispose of
hazardous wastes or acutely hazardous wastes at their own
facilities are subject to the full regulatory requirements of
40 CFR Parts §264 through §270 which pertain to the operation,
maintenance and permitting of treatment, storage and disposal
facilities.
Generators must send heptachlor seed treatment products that
are not treated or disposed of on site to a hazardous waste
facility permitted to accept them.
Generator - one who holds or generates more than 1 kilogram (2.2
pounds) of acutely hazardous waste [heptachlor seed treateraent
products, a listed acutely hazardous waste (PO59)] or more than
1,000 kilograms (2,200 pound of hazardous waste in any calendar
month.
-------
A hazardous waste "generator" as defined above must comply with
all applicable hazardous waste management requirements set forth
in 4G CFR Part 262, Standards Applicable to Generators of Hazardous
Waste. Those who choose to transport their own hazardous waste
must comply with 40 CFR Part 263, Standards Applicable to
Transporters of Hazardous Waste.
If a generator stores his/her waste for longer than 90 days,
then he/she must obtain a RCRA hazardous waste storage permit
and comply with the requirements of 40 CFR Part 264 and 40 CFR
Part 265. An extension of 30 days may be granted by the Regional
Administrator under certain emergency situations.
Generators who choose to store or to treat beyond the allowances
provided in § 262.34(a) or to dispose of hazardous wastes or acutely
hazardous wastes at their own facilities are subject to the full
regulatory requirements of 40 CFR Parts 264 through 270 which
pertain to the operation, maintenance and permitting of treatment,
storage and disposal facilities.
Generators must send heptachlor seed treatment products that are
not treated or disposed of on-site to a hazardous waste facility
permitted to accept them.
pusolete seed, which are no longer viable or suitable for planting and
which have been treated with heptachlor are not "listed" hazardous wastes
in 40 CFR 261 Subpart D. Their status as "characteristic" hazardous
wastes under 40 CFR Subpart C 261.20 through 261.24 and 40 CFR Part 261
Appendix I, II and III must be determined by the generator under 40 CFR
261 .11.
It should be kept in mind, however, that some serious environmental inpacts
have resulted from the inappropriate disposal of obsolete heptachlor-treated
seeds. Every effort should be made to plant existing stocks of
heptachlor-treated seeds in accordance with good agronomic practices
before they become obsolete.
Should the generator find that obsolete heptachlor-treated seed is a
"characteristic" hazardous waste under 40 CFR 262.11, then the seed may be
stored, treated or disposed of only at a permitted hazardous waste facility.
EPA recommends giving serious consideration to incineration.
On the other hand, if after the aforementioned analysis, the obsolete
heptachlor-treated seeds are determined to be non-hazardous, the obsolete
heptachlor-treated seeds could be landfilled in accordance with the individual
state and local requirements for disposal of solid waste. If landfill of
the seed is not viable in your area, then consideration must again be
given to incineration as the appropriate means of destruction.
-------
- £
5. CONTACT PERSON AT EPA, OFFICE OF PESTICIDE PROGRAMS:
James G. Touhey
Senior Agricultural Advisor (H-7506C)
Field Operations Division
Office of Pesticide Programs
Environmental Protection Agency
401 M Street, SW
Washington, D.C. 20460
Office location and telephone number:
Room 710
Crystal Mall, Building No. 2
1921 Jefferson Davis Highway
Arlington, VA 22202
(703) 557-5664
6. CONTACT FOR ADDITIONAL INFORMATION REGARDING DISPOSAL
For those states which have RCRA authorization, a concerned individual
should contact the hazardous waste management agency of that state for
additional information concerning the state disposal requirements (see
Appendix for list of authorized states and ".heir addresses and phone
number) .
For non-authorized states the concerned individual should contact the
hazardous waste management division of the EPA region in which his/her
state falls (see Appendix for list of states by regions).
In addition, concerned parties may call the RCRA/Superfund Hotline
toll free (1-800-9346) or may call commercially on (1-202-382-3000) for
more detailed information concerning RCRA requirements.
-------
Pesticide Fact Sheet
Nane of chemical: Lincane
Fact Sheet Number: 73
Date Issued: September 30,1985
Reason for issuance: Registration Standard
1. Description of Chemical
Generic Name: Gamma Isomer of 1,2,3,4,5,6-hexachloro-
cyclohexane
Common Name: Lindane -•"'
Trade Names: Exagamma, Forlin, Gallogamma, Gammaphex,
Gammex, Gexane, Grammapoz, Grammexane,
Inexit, Kwell, Lindafor, Lindagrain,
Lindagram, Lindagranox/ Lindalo, Lindamul,
Lindapoudre, Lindaterra, Lindex, Lindust,
Lintox, Noyigram, and Silvanol
EPA Shaughnessy Code: 009001
Chemical Abstracts Service (CA) Number: 58-89-9
Year of Initial Registration: 1950
Pesticide Type: insecticide/acaracide
Chemical Family: chlorinated hydrocarbon
U.S. Producer: None
Foreign Producers: Celamerck GmbH KG
Ingelheim, Federal Republic of Germany
Rhone Poulenc Phytosanitaire
Lyon, France
Mitsui, Inc.
Fukuoka, Japan
Tianjin Interntl. Trust & Investment Corp.
Tianjin, China .
2. USE PATTERNS AND FORMULATIONS
Application sites: field and vegetable crops (including seed
treatment) and non-food crops (ornamentals and tobacco),
greenhouse food crops (vegetables) and non-food crops (or-
namentals), forestry (including Christmas tree plantations),
domestic outdoor and indoor (pets and household), commercial
indoor (food/feed storage areas and containers), animal
premises (including manure), wood or wooden structures, and
human skin/clothing (military use only).
Percent of lindane used on various crops/sites:
Hardwood Lumber 19%
Seed Treatment 48%
Forestry <1%
Livestock 20%
Pineapple 2%
Ornamentals 2%
Pecans 3%
Pets 3%
Structures <1%
Household 1%
Cucurbits 1%
-------
Types and methods of applications: dip tank solution
(livestock, lumber, and pets), as a livestock spray, by
ground equipment delivering a ground or foliar spray
or dust, by soil incorporation, by soil injection in
combination with a fumigant (for the pineapple use only),
as a smoke (for greenhouse fumigation only), as a dust
for human skin/clothing (military use only).
Application rates: ranged from 0.25 to 2.25 oz/100 Ib of
seed for seed treatment; 0.1 to 2.06-lb/A for. foliar and
soil treatment; 0.8 to 1.5 oz/50,000 ft3 of greenhouse;
0.006 to 0.11 Ib/gal for bark; 0.023 to 3% sprays, dips,
and dusts for indoor and animal treatment; <0.01 lb/1,000
ft2 for animal premises; <4 lb/1000 ft2 (14.64% solutions
for wood and wooden structures; and 1% dust for human
skin/clothing treatment (military use only).
Types of formulations: 0.27%-11.2% impregnated formulations,
0.5-75% Dusts, 3%-73% wettable powders, 0.5-25% liquids,
0.25-3% pressurized liquids, 1-4% flowable concentrates,
0.45-40% emulsifiable concentrates,
3. SCIENCE FINDINGS
Summary Science Statement: Lindane is a chlorinated hydro-
carbon of moderate mammalian acute toxicity. Lindane has
been shown to be oncogenic in mice but it is not genotoxic.
The Agency has concluded that lindane is a possible human
carcinogen. The Agency is requiring that another rat
chronic/oncogenicity bioassay be performed. Lindane has
been associated with possible induction of blood dyscrasias
(aplastic anemia). The Agency is requiring a laboratory
animal study to permit assessment of lindane's potential
to cause blood dyscrasias. Other toxicology studies
demonstrate systemic toxicity, targeting the liver and
kidney. Lindane's behavior in the environment is not
well defined. The Agency is requiring a full complement
of environmental fate studies. Lindane is slightly to
moderately toxic to birds and highly toxic to some aquatic
organisms. Lindane is highly toxic to honeybees and
certain beneficial parasites and predacious insects.
Additional studies on the ecological effects of lindane
are required.
Chemical Characteristics
Technical lindane is a white crystalline solid.
Its melting point is 112° - 113°C.
It is soluble in most organic solvents and is relatively
insoluble in water.
Lindane is stable to light, heat, air and strong acids,
but decomposes to trichlorobenzenes and HCL in alkali.
-------
Tex:colocv
Acute Oral: 88 me/kg, Toxicity Category II
Acute Dermal: 300 mg/kg Toxicity Category II
Acute Inhalation: Data gap
Primary Eye Irritation: Data gap
Primary Skin Irritation: Irritant Toxicity Category I
Skin Sensitization: Data gap
Major Routes of Exposure: Human exposure from 'lindane
is greatest during mixing, loading, and application.
Dermal, ocular, and inhalation exposures to workers may
occur during application. Exposure can be reduced by
the use of approved respirators, protective clothing,
and goggles.
Oncogenicity: A two-year mouse oncogenicity study
demonstrated increased incidences of liver tumors
(male & female) when dosed at 400 ppm. An 80-week mouse
feeding study demonstrated increased incidences of
liver tumors at the 80 ppm level but not at the 160 ppm
level. Two subchronic studies provide supportive evidence
of oncogenicity. The mouse studies were referred to the
Agency's Carcinogen Assessment Group (CAG) for evaluation.
Based on the weight of the evidence, CAG classifed lindane
in the range B2-C. OPP believes that the classification
C is appropriate at this time and, therefore, will regulate
lindane as a class C carcinogen, pending receipt of the
required rat oncogenicity study.
Metabolism: Lindane does not appear to bioaccumulate in
tissues.
Teratology: Teratology studies in the rat, rabbit, and
mouse were negative for teratogenic effects.
Reproduction: A 3 generation rat reproduction study was
negative at 100 ppm.
Mutagenicity: Available data show lindane to be negative
for gene mutation in bacterial Ames assays, host mediated,
and dominant lethal assays. Lindane has been reported as
negative in other in vitro assays for DNA damage/repair
in bacteria, rat and mouse hepatocytes, and mammalian cell
transformation assays.
Physiological and Biochemical Characteristics
Mechanism of pesticidal action: Lindane acts in the
nervous system through unknown mechanisms.
Metabolism and persistence in plants and animals: The
metabolism of lindane in plants and livestock animals
has not been adequately described. Additional data are
being required.
-------
Environmental Characteristics
Available data are insufficient to assess the
fate of lindane. Data gaps exist for all required studies.
Preliminary adsorption data indicate that lindane has a low
mobility in mineral soils and is relatively immobile in
muck soils; however/ the potential for lindane contamina-
tion of surface and ground water exists based on the results
of a monitoring study conducted in certain southern states.
.^'
Ecological Characteristics
Avian acute oral toxicity: Data Gap
Avian dietary toxicity: 882 ppm for bobwhite quail,
561 ppm for ring-necked pheasant (moderately toxic),
and >5000 ppm for mallard duck (practically nontoxic).
Freshwater fish acute (LCsg) toxicity: cold water species
(rainbow trout) 27 ppb for technical lindane (very
highly toxic), warm water species (bluegill) 68 ppb for
technical lindane (very highly toxic).
Aquatic freshwater invertebrate toxicity: Daphnia 460 ppb
(highly toxic). Additional data are required to fully
characterize the ecological effects of lindane.
Available data are insufficient to fully assess the environ-
mental fate of and the ecological effects from lindane.
Required Unique Labeling Summary
All manufacturing-use and end-use lindane products must
bear appropriate labeling as specified in 40 CFR 162.10.
In addition, the following information must appear on the
labeling:
All manufacturing-use products must state that they are
intended for formulation into other manufacturing-use
products or end-use products only for registered uses.
All manufacturing-use products shall contain the following
text in the Environmental Hazards section of the label:
"This pesticide is toxic to fish and aquatic invertebrates.
Do not discharge effluent containing this product into
lakes, streams, ponds, estuaries, oceans, or public waters
unless this product is specifically identified and addressed
in an NPDES permit. Do not discharge effluent containing
this product into sewer systems without previously notifying
the sewage treatment plant authority. For guidance, contact
your State Water Board or Regional Office of the EPA."
-------
All end-use products containing lindane that were classsi-
fied as restricted by the Final Notice of Determination
concluding the RPAR shall continue to be classified for
restricted use and the restricted use label must include
the cancer hazard warning statement.
All end-use products shall continue to carry the applicator
protection statements previously required by the Final
Notice of Determination concluding the RPAR. Products
with directions for foliar application to crops whose
culture involves hand labor must bear the statements
required under PR Notices 83-2 and 84-1 for farmworker
safety, including.a 24 hour re-entry interval.
End-use products with directions for spraying uninhabited
buildings or empty storage bins must include protective
clothing requirements, including the use of a respirator.
All end-use products for indoor use shall indicate that
lindane is not to be applied to edible product areas
of food processing plants or to serving areas while
food is exposed.
All end-use products with uses on livestock or livestock
premises must indicate not to contaminate food, feed,
or water with the pesticide. Also, there must be a
statement that indicates lindane is not to be applied
to poultry houses, dairy barns, and milk rooms. All
feed or water troughs must be covered and all livestock
should be removed from animal shelters (barns, sheds,
etc.) prior to treatment of the structure.
All end-use products for structural pest control must
indicate that lindane is not to be applied in currently
occupied areas (i.e. regular living or working areas,
including finished basements or finished attics) of
homes or other buildings. The characterization of a
use site depends upon its intended function and not
upon whether there are occupants in the area at the
time of treatment.
Tolerance Assessment
The Agency is unable to complete a full tolerance assess-
ment because the metabolism of lindane in plants and
livestock animals has not been adequately described.
Also, seed treatment is now considered to be a food
use requiring a tolerance unless results of a radio-
labeled study indicate that there is no translocation
to edible parts of the plant following seed treatment.
No new tolerances, except those required to support
the existing seed treatment uses of lindane, will be
considered until the toxicology and residue chemistry
data ga , identified in the Standard have been filled.
-------
Established tolerances are puoiisnec in 40 CFR ISO.133
A listinc cf U.S. tolerances includes the following:
Commodity
Appl es
Apricots
Asparagus
Avocados
Broccoli
Brussels Sprouts
Cabbage
Cattle, fat
Caul iflower
Celery
Cherri es
Collards
Cucumbers
Eggplant
Goats, fat
Grapes
Guavas
Hogs, fat
Horses, fat
Kale
Kohlrabi
Lettuce
Mangoes
Melons
Mushrooms
Mustard Greens
Nectarines
Okra
Onions, dry bulb only
Peaches
Pears
Pecans
Peppers
Pineapples
Plums, incl. Prunes
Pumpkins
Quinces
Sheep, fat
Spinach
Squash
Summer Squash
Strawberries
Swiss Chard
Tomatoes
Tolerance expressed
as parts per million
1.
1.
1.
1.
1.
1.
1.
7.
1.
1.
1.
1.
3.
1.
7.
1.
1.
4.
7.
1.
1.
3.
1.
3.
3,
1,
1,
1,
1,
1,
1,
1.
1,
1.
3.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.01
1.0
7.0
1.0
3.0
3,
1,
1.0
3.0
-------
The best available data for determining an interim accept-
able daily intake level of lindane is a subchronic feed-
ing study in rats (1983) which demonstrated a No Observed
Effect Level (NOEL) of 4 ppm. Based on dietary analysis,
food intake, and body weight data from this particular
study, the NOEL of 4 ppm is equivalent to 0.3 mg/kg/day.
Using this latter value and a safety factor of 1000, the
Provisional Acceptable Daily Intake (PADI) is 0.0003
mg/kg/day and the Maximum Permissible Intake (MPI) for
a 60 kg person is 0.018 mg/day. The Theoretical Maximum
Residue Contribution (TMRC) for lindane, based on all
established tolerances, is 1.4189 mg/day/1.5 kg of diet
The percent of the MPI used by the TMRC is 7883%.
Although the theoretical concentration from existing
tolerances greatly exceeds the MPI, FDA market basket
surveys indicate that actual residues of lindane are
much lower. The Agency believes that the actual risk
to consumers from the daily consumption of lindane,
. based on FDA market basket data for 1978-1982, is only
0.000002 mg/kg/day. Under this scenario, only 0.7% of
the Maximum Permissible Intake is actually used.
4. SUMMARY OF REGULATORY POSITION AND RATIONALE
The Agency has determined that it should continue the
registration of all currently registered uses of lindane.
The Agency concluded in the RPAR that most uses of lindane
would be continued because a risk/benefit assessment
demonstrated that the benefits from the uses outweighed
the risks provided certain labeling restrictions, such as
restricting some uses to certified pesticide applicators,
requirements for protective clothing, and label statements
describing necessary precautions were added to all lindane
labels. The Agency has reevaluated that decision and
concludes that, except as described below, the risks and
benefits are substantially the same as those described in
the RPAR process.
Based on FDA market basket residue levels, which the
Agency believes in this case is more generally representa-
tive of actual residues than theoretical calculations,
the estimate of the upper 95% confidence level for excess
cancer risk is 2xlO~6. The estimate of the upper 95%
confidence level for excess cancer risk to applicators' for
various uses is estimated to be from 10~4 to 10~7, depend-
ing upon the site and method of application. The Agency
has recalculated the exposures and margins of safety for
applicators for 24 use patterns and has developed initial
calculations for mixer/loaders or combination mixer/loader/
applicator for 3 use patterns (forestry, cucurbits, and
pecans). This reassessment is based on current Agency
methods and models and consideration of a lower NOEL from
the subchronic rat study for uses involving subchronic
type exposure.
-------
Based on these calculations, the Agency will initiate
Special Review for the forestry and uninhabited buildings
and empty storage bins spray uses on the basis of risks
to applicators. Use of protective clothing, including an -
MSHA/NIOSH approved respirator, is now being required for
spraying uninhabited buildings and empty storage bins
while the Special Review is underway. Protective clothing
requirements stipulated in the Final Notice of Determination
of the lindane RPAR will continue for all other uses. No
significant changes from the exposure'~values presented in
PD-4 occurred for twelve of the uses. The calculated
exposures for cucurbits, crawl spaces, dog dusts, dog
dips, shelf paper, and commercial moth sprays increased
by approximately an order of magnitude, but are still
acceptable. Applicator exposure data is being required
for seed treatment, structural treatment, livestock
spraying, dog washes, dog shampoos, and dog dusts. Air
monitoring data are required for the structural treatment
and dog treatment uses. Exposure studies are required,
in addition to toxicity studies, to support the registra-
tions for application of lindane to human skin/clothing
by the military.
Lindane seed treatments were registered many years
ago as non-food uses not requiring tolerances. The Agency
now considers seed treatment t:o be a food use and requires
data to support a tolerance unless results of a radiolabeled
study indicate that there is no translocation to edible
parts of the plant following seed treatment. Data from
one of these two alternatives must be submitted to support
the seed treatment uses. No new tolerances, except those
required to support the existing seed treatment uses, will
be considered until the chronic feeding and residue chem-
istry data gaps identified in the Standard have been
filled.
Available data are insufficient to fully assess the
environmental fate of lindane and its ecological effects.
A full complement, of such studies is being required. Pre-
cautionary label statements will continue to be required.
5. Summary of Major Data Gaps Due Date
- An acute inhalation study 9 months
- A 90-day inhalation study 15 months
- A dermal sensitization study 9 months
- A 21-day dermal toxicity study 12 months
- A rat chronic/oncogenicity study 50 months
Laboratory animal blood dyscrasias study pending
- Full complement of environmental fate studies 39 months
Plant metabolism studies 24 months
Livestock animal metabolism studies 18 months
- Residue chemistry studies on all crops, 48 months
including seed treatment uses
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Contact Person at E?A
George T. LaRocca
Product Manager (15)
Insecticide-Rodenticide Branch
Registration Division (TS-767C)
Office of Pesticide Programs
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Office location and telephone number:
Room 204, Crystal Mall Building #2
1921 Jefferson Davis Highway
Arlington, VA 22202
703-557-2400
DISCLAIMER: THE INFORMATION PRESENTED IN THIS PESTICIDE
PACT SHEET IS FOR INFORMATIONAL PURPOSES ONLY AND IS NOT
TO BE USED TO FULFILL DATA REQUIREMENTS FOR PESTICIDE
REGISTRATION AND REREGISTRATION.
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United States DHice o' Pesticides and Toxic Substances
Environmental Protection Office o: Pctficioe Programs (TS-766C;
Agency Wsshingion, uC 2046C
&EPA Pesticide
Fact Sheet
Name of Chemical: METHOXYCKLOR
Reason for Issuance: REGISTRATION STANDARD
Date ISSUed: December 1988
Fact Sheet Number: is?
1. DESCRIPTION OF CHEMICAL
Generic name: 1,1,l-trichloro-2,2-bis(4-
methoxyphenyl) ethane
Common name: Methoxychlor
Trade Names: Marlate, Prentox, and Methoxcide
Other Chemical Nomenclature: 1,1,l-trichloro-2,2-di(4-
methoxyphenyl)ethane; 1,1-
(2,2,2-tri chloroethylidene)-
bis[4-methoxybenzene]; 1,1,1-
trichloro-2,2-bis(p-
methoxyphenyl)ethane; 2,2-
bis)p-methoxyphenyl)-!,!,!-
trichloroethane
CA.S Registry No.: 72-43-5
EPA Pesticide Chemical Code (Shaughnessy Number): 034001
Empirical Formula: C16H15Cl302
Molecular Weight: 345.7
Year of initial registration: 1948
Pesticide type: Insecticide/Acaric\de
Chemical family: Chlorinated Hydrocarbon
U.S. Registrants: Chemical Formulators; Prentiss Drug &
Chemical Co., J.R. Simplot Co.;
Dynachem Industries; Clover Chemical
Co.; Drexel Chemical Co.; Kincaid
Enterprises; and Wesley Industries
-------
Enterprises; and '\esley industries
2. USE PATTERNS AND FORMULATIONS
Registered
Uses:
TERRESTRIAL FOOD CROP use: (1) seed treatment only use
on grains and various vegetables; (2) foliar application
(including seed treatment) use on vegetables and fruits;
and (3) foliar application only use on vegetables and
fruits
TERRESTRIAL NON-FOOD CROP use on grasses, ornamentals and
trees
GREENHOUSE FOOD CROP use on mushrooms
DOMESTIC AND NON-DOMESTIC OUTDOOR use around dwellings
and for garbage and sewer areas, general urban outdoor
use
AQUATIC FOOD use on cranberry
AQUATIC NON-FOOD use for mosquito larvae control in
aquatic sites, such as beaches, lakes, marshes and
rivers
FORESTRY use on forest trees
INDOOR use on: (1) postharvest stored grain commodity
and premise treatment; (2) direct animal treatment for
dogs, cats, and farm animals; (3) agricultural premise
use; (4) kennels, dv>g sleeping quarters and cat sleeping
quarters; (5) indoor domestic dwellings for use on
household contents such as human clothing (including
woolens); (6) direct application to humans; (7)
commercial and industrial use in food processing, storage
transportation areas and equipment
Pests Controlled: various nuisance species (some of public
health significance) including cockroaches,
mosquitoes, flies and chiggers; various
arthropods attacking field crops,
vegetables, fruits, ornamentals, stored
grain, livestock and domestic pets
Methods of Application: sprays, fogs, paints,
ground and aerial equipment,
animal dust-bags, dips, sprays
and back-rubbers
Formulations: Wettable powders, dusts, emulsifiable
2
-------
concentrates, flowatle concentrate.0.
liquid soluble concentrates, granules,
ready-to-use products (liquids) ana
pressurized liquids
3. SCIENCE FIKTDIKGS
Summary Science Statement
With the exception of one mutagenicity study, there are no
acceptable acute, subchronic, or long-term
toxicology/oncogenicity studies available to support technical
methoxychlor. In the acceptable mutagenicity study, an
unscheduled DNA synthesis assay in mammalian cells in culture, no
abnormal DNA synthesis was noted at any of the dose levels
tested.
Based on acceptable laboratory data, technical methoxychlor
is characterized as very highly toxic to fish and aquatic
invertebrates, and practically nontoxic to birds and bees. Based
on theoretical calculations, both terrestrial and aquatic uses of
methoxychlor may pose a hazard to aquatic organisms, although
there is no field evidence to support this. The impacts of
methoxychlor use to nontarget organisms will be assessed upon
receipt of ecological effects and environmental fate data.
The environmental fate of methoxychlor cannot be
characterized because acceptable data are lacking. Preliminary
data suggest that methoxychlor is unlikely to contaminate
groundwater because of its low solubility and high rate of
adsorption to soil particles.
The nature of the residues of methoxychlor in plants and
animals is not adequately understood. None of the tolerances
for methoxychlor is adequately supported. Plant and animal
metabolism studies, residue studies, analytical methodology,
processing studies, and storage stability data are needed before
the Agency can determine the adequacy of current tolerance
levels.
Chemical/Physical Characteristics of the Technical Material
Chemical/Physical
Characteristics:
Color: Data Gap
Physical State: Crystalline solid (Farm
Chemicals, 1987)
Odor: Data Gap
Melting Point: 89 °C (Farm Chemicals,
1987)
Specific Gravity: Data Gap
Solubility: Very soluble in aromatic
chlorinated, or ketonic solvents,
-------
somewhat soluble in paraffinic
types; essentially insoluble
in water (Farm Chemicals, 1987}
Vapor Pressure: Data Gap
Flammabi lity : Data Gap
pH: Data Gap
Toxicology Characteristics
With the exception of one mutagenicity study, there are no
acceptable acute, subchronic or long-term toxicology/oncogenicity
studies available to support technical methoxychlor. In the
mutagenicity study, a mammalian cell in culture unscheduled DNA
synthesis assay (UDS assay), no increase in abnormal DNA
synthesis was noted.
Environmental Characteristics
The Agency is unable to assess the environmental fate of
methoxychlor because acceptable data are lacking. Preliminary
data indicate that methoxychlor is stable to hydrolysis (half-
life > 200 days); photodegradation in water (half-life of 4.5
months) ; and aerobic soil metabolism (half-life. > 3 months...in -
sandy loam soil). The half-life for anaerobic soil metabolism is
reported at less than 1 month in sandy loam soil. Preliminary
data also indicate that methoxychlor has a high adsorption rate
to soil sediment (K^ value is 620).
Ecological Characteristics
Based on acceptable laboratory data, technical methoxychlor
is characterized as practically nontoxic to birds on both an
acute oral and subacute dietary basis and very highly toxic to
fish and aquatic invertebrates on an acute basis. There is
sufficient information to characterize methoxychlor as
relatively nontoxic to honey bees. The acute toxicity value = 24
ug/bee.
- Acute LD50 (bobwhite):
>2510 mg/kg
- Dietary LC50
>5620 ppm (upland gamebird)
- Freshwater invertebrates toxicity (96-hr LC50) for
daphnid .78 ppb
- Fish acute toxicity (96-hr LC50) for rainbow trout:
1.31 ppm
- Fish acute toxicity (96-hr LC50) for brook trout:
0.009 ppm
Tolerance Assessment
Tolerances have been established for residues of
-------
methoxychlor in a variety of raw agricultural commodities, ::i
meat, fat and meat byproducts (40 CFR 180.120). Tolerances are
expressed in terms of methoxychlor per se.
The nature of the residues of methoxychlor in plants and
animals is not adequately understood. None of the tolerances
for methoxychlor is adequately supported. Plant and animal
metabolism studies, residue studies, analytical methodology,
processing studies, and storage stability data are needed before
the Agency can determine the adequacy of current tolerance
levels.
The Preliminary Limiting Dose (PLD) of methoxychlor is .005
mg/kg/day. This is based on a rabbit teratology study with a No
Observed Effect Level (NOEL) of 5 mg/kg/day for increased loss
of litters and an uncertainty factor of 1000 to account for
inter- and intraspecies differences, poor quality of the study
used and total incompleteness of the subchronic and chronic
toxicity data base. The study is not considered to be adequate
to define a NOEL for purposes of setting an Acceptable Daily
Intake, since the experimental design was considered to be
inadequate. It is being used on an interim basis for calculation
of the PLD. The Agency is unable to complete a tolerance
assessment of methoxychlor because of the incompleteness of the
toxicology and residue chemistry data bases.
4. SUMMARY OF REGULATORY POSITIONS AND RATIONALES
Methoxychlor is not being placed into Special Review at
this time. Since there are so few acceptable studies available
to support registration of products containing methoxychlor, the
Agency is not yet able to make a determination as to whether any
of the criteria of 40 CFR 154.7 have been met or exceeded.
The Agency will not approve any new food uses, including
minor uses for this chemical since none of the tolerances are
adequately supported.
- The Agency is unable to assess methoxychlor's potential for
contaminating groundwater. When data required in the Standard
have been received and evaluated, the Agency will assess the
potential for methoxychlor to contaminate groundwater.
- Updated worker safety rules are required for end-use product
labels.
-The Agency is not establishing a longer reentry interval for
agricultural uses of methoxychlor beyond the minimum reentry .
interval (sprays have dried, dusts have settled, and vapors have
dispersed).
- Revised and updated fish and wildlife statements are
-------
required for end-use product labels. Since methoxychlor is
practically nontoxic to bees, the bee statement imposed under
under PR Notice 68-19 is no longer appropriate. Registrants mus
remove the bee statement from the labeling.
- The Agency is not classifying methoxychlor as a restricted
use pesticide at this time, since it is unable to determine if
this pesticide meets any of the risk criteria of 40 CFR 152.170
Upon receipt of data required under this Standard, the Agency
will apply the criteria of 40 CFR 152.170 to determine if any
uses of methoxychlor warrant restricted use classification.
- Since methoxychlor is an analogue of DDT, the Agency is
requiring specific analysis of methoxychlor for the potential
impurities 1,1,l-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT)
and other structurally similar compounds.
SUMMARY OF OUTSTANDING DATA REQUIREMENTS
Toxicology
Acute Oral Toxicity
Acute Dermal Toxicity
Acute Inhalation Toxicity
Eye Irritation
Dermal Irritation
Dermal Sensitization
21-Day Dermal Toxicity
Chronic Testing (rodent)
Chronic Testing (non-rodent)
Oncogenicity (rat)
Oncogenicity (mouse)
Teratogenicity (rat)
Teratogenicity (rabbit)
Reproduction
Gene Mutation
Other Mechanisms of
Mutagenicity
Metabolism
Time Frame
9
9
9
9
9
9
9
50
50
50
50
15
15
39
9
12
24
Months
Months
it
it
ii
it
ii
it
n
ii
n
n
n
n
n
n
n
Environmental Fate/Exposure
Hydrolysis
Photodegradation in Water
Photodegradation on Soil
Aerobic Soil Metabolism
Anaerobic Soil Metabolism
Anaerobic Aquatic Metabolism
Aerobic Aquatic Metabolism
Leaching and Adsorption/
Desorption
9 Months
9 "
9 "
27 "
27
27
n
ii
27 "
12
"
-------
Aquatic Dissipation
Forestry
Soil, Long-term
Confined Rotational Crop
Accumulation in Irrigated Crops
Accumulation in Fish
Accumulation in Aquatic
Nontarget Organisms
Fish and Wildlife
Avian Reproduction
Freshwater Fish LC50 Studies (TEP)
Freshwater Invertebrate LC50 Studies (TEP)
Estuarine and Marine
Organisms LC5Q Studies (TEP)
Fish Early Life Stage
and Invertebrate Life Cycle
Simulated or Actual Field
Testing-Aquatic Organisms
Seed Germination/Seedling
Emergence
Aquatic Plant Growth
Residue Chemistry
Residue data - Raw Agricultural Commodities
Processing Studies
Plant and Animal Metabolism
Storage Stability
Residue Analytical Methods
Product Chemistry
All Data
27 "
27 "
39 "
39 "
39 "
12 "
12 "
24 Months
9 "
9 "
12 "
15 "
24 "
9 "
9 "
Months
18
24
18
15
15
9 -15 Months
6. Contact Person at EPA
Dennis H. Edwards Jr.
Product Manager (12)
Insecticide-Rodenticide Branch
Registration Division (TS-767)
Environmental Protection Agency
Washington, DC 20460
Tel. No. (703) 557-2386
-------
DISCLAIMER: The information presented in this Chemical
Information Fact Sheet is a summary only and may not be used tc
fulfill data requirements for pesticide registration and
rereaistration.
-------
March 3 > , '95'
TOXWHEKE
Health Advisory
Office of Drinking Water
U.S. Environmental Protection Agency
I. INTRODUCTION
The Health Advisory (HA) Program, sponsored by the Office of Drinking
Water (ODW), provides information on the health effects, analytical method-
ology and treatment technology that would be useful in dealing with the
contamination of drinking water. Health Advisories describe nonrequlatory
concentrations of drinking water contaminants at which adverse health effects
would not be anticipated to occur over specific exposure durations. Health
Advisories contain a margin of safety to protect sensitive members of the
population.
Health Advisories serve as informal technical guidance to assist Federal,
State and local officials responsible for protecting public health when
emergency spills or contamination situations occur. They are not to be
construed as legally enforceable Federal standards. The HAs are subject to
change as new information becomes available.
Health Advisories are developed for One-day, Ten-day, Longer-term
(approximately 7 years, or 10% of an individual's lifetime) and Lifetime
exposures based on data describing noncarcinogenic end points of toxicity.
Health Advisories do not quantitatively incorporate any potential carcinogenic
risk from such exposure. For those substances that are known or probable
human carcinogens, according to the Agency classification scheme (Group A or
B), Lifetime HAs are not recommended. The chemical concentration values for
Group A or B carcinogens are correlated with carcinogenic risk estimates by
employing a cancer potency (unit risk) value together with assumptions for
lifetime exposure and the consumption of drinking water. The cancer unit
risk is usually derived from the linear multistage model with 95% upper
confidence limits. This provides a low-dose estimate of cancer risk to
humans that is considered unlikely to pose a carcinogenic risk in excess
of the stated values. Excess cancer risk estimates may also be calculated
using the One-hit, Weibull, Logit or Probit models. There is no current
mderstanding of the biological mechanisms involved in cancer to suggest that
any one of these models is able to predict risk more accurately than another.
Because each model is based on differing assumptions, the estimates that are
derived can differ by several orders of magnitude.
-------
Toxaonene
Xar
This Health Advisory is based on information presented in the Office
of Drinxing Water's Health Effects Criteria Document (CD) for Toxaphene
(U.S. EPA, 1985a). The HA and CD formats are similar for easy reference.
Individuals desiring further information on the toxicological data base
or rationale for risk characterization should consult the CD. The CD is
available for review at each EPA Regional Office of Drinking Water counter-
part (e.g., Water Supply Branch or Drinking Water Branch), or for a fee
from the National Technical Information Service, U.S. Department of Commerce,
5265 Port Royal Rd., Springfield, VA 22161, PB # 86-118049. The toll-free
number is (800) 336-4700; in the Washington, D.C. area: (703) 487-4650.
II. GENERAL INFORMATION AND PROPERTIES
CAS No. RN 8001-35-2
Structural Formula
Since the technical grade product is produced by free radical reac-
tions initiated by chlorine and ultraviolet light, toxaphene is a
complex mixture of poly chlorinated camphenes and bornanes with an
average empirical formula of CiQH10c^8 and an average molecular
weight of 414. In fact, more than 177 incompletely characterized
components have been separated (Holmstead et al., 1974).
Synonyms
Uses
Agricide maggot killer, Alltex, Camphechlor, Chem-Phene,
Compound 3956, and Kamfochlor.
Pesticide used to combat certain worms and insects such as cotton
boll weevils and ectoparasites on cattle and sheep (Meister, 1987).
Properties (Windholz, 1983)
Physical State
Softening Range
Density
Vapor Pressure
Hater Solubility
Octanol/Water Partition
Coefficient
Occurrence
Amber, waxy solid, with a mild
terpene odor
70-95°C
1.66 g/mL at 27°C
0.17-0.40 mmHg at 25°C
Approx. 3 mg/L or 0.5 mg/L at 25°C
Approx. 3,300 or 825
Toxaphene is an insecticide which up to 1982 was widely used on
soybeans, cotton, corn, wheat and other crops. The estimated pro-
duction of toxaphene in 1982 was 3.7 million Ibs. In 1982, all
major uses of toxaphene were canceled by EPA. Current use levels
of toxaphene are believed to be very low.
-------
-oxapnene Marcr. 2' ,
0 Because toxaphene is a co-plex mixture of highly chlorinated com-
pounds, it is difficult to assess its behavior in the environment.
Ir. general, tcxaphene binds to soil and resists migration. Toxaphene
is considered to be an extremely persistent pesticide. Soil half-
lives of 20 years have been reported. Toxaphene is reported to
biodegrade slowly under certain anaerobic conditions.
0 Toxaphene is not degraded in surface water; however, its tendency
to bind tightly to sediments usually results in its rapid removal
from the water column. Toxaphene has been reported to bioaccumulate
readily in aquatic species.
c Toxaphene has not been found in drinking water supplies in measurable
quantities. Studies of surface and ground waters generally have
not found detectable levels. A few positive samples of surface
water have reported levels of approximately 1 ppb (U.S. EPA, 1983).
0 Toxaphene has been reported to occur as a contaminant in food,
especially fish and other seafood. Toxaphene also has been detected
in air at low levels (U.S. FDA, 1984). Food appears to be the
major source of toxaphene exposure. Based upon the recent cancel-
lations of uses for toxaphene, occurrences of toxaphene in food and
water are expected to decline.
III. PHARMACOKINETIC3
Absorption
Toxaphene is absorbed through the skin (especially if mixed with
xylene), the lung and the gut (IUPAC, 1979; IARC, 1979). The rate
of absorption depends upon the vehicle for its administration.
Distribution
In general, toxaphene appears to be metabolized rapidly and its
metabolites quickly excreted in most species, with fat as the
preferred tissue of storage (IUPAC, 1979).
Twenty days after a single 20 mg/fcg dose of 36C1-toxaphene was
administered orally to rats, 36(T1 levels in RBCs and brain were
still increasing (Crowder and Dindal, 1974). A total of 2.2% of
the 36C1 dose remained in the tissues.
Transplacental transfer of toxaphene (less than 1% of the admini-
stered dose) has been reported in Sprague-Dawley rats by Pollack
and Hillstrand (1982).
Metabolism
Dechlorination and oxidative degradation each account for approxi-
mately half of the metabolism of toxaphene. The hepatic mixed
function oxidase system involving cytochrome P-450 is the active
degradation mechanism for -his substance in rats (Chandurkar and
-------
Toxaphene March 31, 1967
-4-
Matsor.ura, 1979). The toxicity of toxaphene is potentiated in mice
by piperonylbutoxide , a known P-4SO inhibitor (Saleh et al., 1977).
Excretion
The half-life of toxaphene in rats after administration of single
oral doses of 14C- or 36ci-labeled toxaphene was less than a week
(Crowder and Dindal, 1974; Ohsawa et al., 1975). Most of the
36ci-labeled toxaphene was excreted within 6 to 7 days and little
remained in the tissues.
Approximately 49% of 36_d_toxaphene was eliminated in the urine of
rats 14 days after oral administration of 14.2 nig/kg bw. The feces
contained 27% of the 36C1-labeled metabolite after 14 days (Ohsawa
et al., 1975).
Toxaphene was excreted in the milk of cows fed 0 to 20 ppm toxaphene
in the diet for 77 days. Toxaphene levels in milk ranged from 0.043
to 0.179 mg/L and were dependent on the administered concentration
(Zweig et al. , 1963). Following cessation of exposure, residues in
miIX decreased to undetectable levels after two weeks in cows given
levels lower than 10 ppm. At the 20 ppm level, residues were still
detected 30 days after administration of the test diet was terminated.
IV. HEALTH EFFECTS
Humans
Toxaphene poisoning in humans is characterized by diffuse stimulation
of the central nervous system (CNS) resulting in salivation, rest-
lessness, hyperexcitability, muscle tremors or spasms, generalized
convulsions and sometimes loss of consciousness. Nausea and vomiting
may follow ingestion. Clonic convulsions also may occur and can be
prevented by barbiturates (McGee et al., 1952).
The IUPAC (1979) has estimated an acute oral LD50 of 60 mg/fcg for
toxaphene.
At lease thirteen deaths from toxaphene poisoning have been recorded
(Hayes, 1975). Most of the fatal cases involved ingestion of toxaphene
by email childern.
Studies of human exposure to toxaphene in the workplace are confounded
because exposure to many chemicals occurred in all of the reported
studies. Two cases of acute aplastic anemia after dermal exposure
to toxaphene/lindane have been reported; one death was due to myelo-
raonocytic leukemia (IARC, 1979).
Animals
Short-term Exposure
Greater than ten-fold differences in toxicity have been documented
for various toxaphene fractic s or components that differed from
-------
-oxapr.e.-.c- .March 3'', '.967
-5-
each other in chemical composition, polarity and soiubilitv (Pollack
an= Kilcore, I978a,b).
c Toxaphene is a CNS stimulant in mammals. Effects of toxic exposures
in humans (hypersensitivity, tremors and convulsions) are similar
to those observed in both rats and dogs (Lehman, 1951).
° Rats fed a protein-deficient diet were more susceptible to toxaphene
poisoning than were rats fed regular laboratory chow, with LD^Q
values of 80 and 220 mg/kg bw, respectively (Boyd and Taylor, 1971).
Clinical signs of depression and stimulation of the CNS were the
same in both groups; however, signs appeared earlier and at lower
toxaphene concentrations in protein-deficient rats. This suggests
that humans who ingest a protein-deficient diet may represent =1
sensitive subpopulation.
Long-term Exposure
0 In a study by Lackey (1949) dogs (breed not indicated, 3 to 8 per
dosage group) were administered toxaphene in corn oil by gavage at
5, 10, 15, 20, 25, 30, 40 or 50 mg/kg/day for an unstated number of
days. The author reported that at 5 mg/kg/day convulsions were
seen after a few days (number not stated). Deaths occurred in all
dosage groups except the two lowest (5 and 10 mg/kg/day). Deaths
were attributed to respiratory failure. Therefore, 5 mg/kg/day is
the LOAEL for convulsions after short-term exposure. No convulsions
were induced after a single dose of 5 mg/kg/day.
0 In a second part of the Lackey (1949) study, dogs were administered
toxaphene at large cumulative doses (176 to 424 mg/kg) at 4 mgfkg/day
for 44 to 106 days. At that level there was widespread degeneration
of the renal tubular epithelium, occasionally accompanied by pyelitis
(inflammation of the renal pelvis). Therefore, 4 Big/kg/day is
identified as the LOAEL for renal effects in this study.
0 In a lifetime feeding study, Fitzhugh and Nelson (1951) observed
increased liver weights with minimal liver cell enlargement in rats
fed a diet containing toxaphene at 25 ppn (approximately 1.25
mg/kg/day based on the dietary assumptions of Lehman (1959)). In a
lifetime study in rats by I%hman (1952), this level resulted in no
effects, whereas 100 ppm (approximately 5 mg/kg/day based on Lehman
(1959)) resulted in fatty degeneration of the liver. Boots Hercules
Agr©chemicals, inc. (not dated) reported liver necrosis in rats fed
toxaphene at 200 ppm (author's conversion: approximately 5 mg/kg/day)
for 3.7 years. Clapp et al. (1971), however, observed no adverse
effects on liver histology even at doses up to 189 ppm (approximately
9.45 mg/kg/day, based on Lehman (1959)). Based on these combined
observations, the LOAEL for liver effects is determined to be 1.25
mg/kg/day. as reported in the Fitzhugh and Nelson (T951) study.
-------
Toxaphene Marcr. 3', 1957
-6-
0 Alien et al. (1963) reported that IgG antibody titers were
depressed significantly and liver weights were increased in female
Swiss-Webster mice (an average of 14 animals per dosage group)
administered toxaphene for 8 weeks at dietary concentrations of
100 ppm and 200 ppm but not at 10 ppm (approximately 15, 30 and
1.5 mgAg/day, respectively, based on the dietary assumptions of
Lehman (1959)). Macrophage phagocytosis was significantly suppressed
in offspring exposed to toxaphene, both transplacentally and while
nursing, at all three dosage levels. Therefore, the LOAEL for this
effect is 1.5 mg/kg/day.
Reproductive Effects
0 Chernoff and Carver (1976) studied the potential fetal toxicity of
toxaphene in CD rats administered toxaphene at doses of 15, 25 or
35 mg/kg/day in corn oil by gastric intubation on days 7 through
16 of gestation. The numbers of rats per group were as follows:
33 control rats, 39 rats at 15 and 25 mg/kg/day, and 16 rats at
35 mg/kg/day. At 35 mg/kg, toxicity was evidenced by 31% maternal
mortality. There was also a dose-related reduction in the weight
gain of dams (p<0.001) at 15 and 25 mg/kg/day. Even though there
was significant maternal toxicity in all treated groups, there were
no dose-related changes in fetal mortality or in the occurrence of
fetal anomalies. Therefore, the LOAEL for this study is 15 mg/kg/day.
Mutagenicity
0 NTP (1963) reported toxaphene to be mutagenic when tested in the
Salmonella/microsomal reverse mutation assay* Hill (1977), summa-
rizing tests done by Litton Bionetics, Inc. (1978) for Hercules, Inc.,
indicated that toxaphene was directly mutagenic only for Salmonella
typhimurium strains TA98 (which detects frameshift mutagens) and
TA100 (nonspecific). By contrast, a "high temperature" toxaphene
(high boiling component) was mutagenic only with activation by rat
liver microsomal preparation (S-9).
0 Toxaphene has been tested in sister chromatid exchange systems,
dominant lethal assays and ONA breakage assays and produced negative
results (U.S. EPA, 1985a).
Carcinogenieity
0 The most definitive study of toxaphene carcinogenicity was conducted
by the Tracer Jitco Co. under contract to the National Cancer Insti-
tute (NCI, 1979), despite the fact that the study was not conducted in
strict accordance with NCI guidelines (control groups contained only
10 aniaals each and paired-feeding was not done). Osborne-Mendel
rats and B6C3F1 nice (SO/sex/treataent group; 10/sex/control group)
were used. Diets fed to male rats initially contained toxaphene at
2,560 and 1,280 ppm and the females received 1,280 and 640 ppm.
For mice of both sexes, the doses were 320 and 160 ppm. Because of
overt toxicity, these concentrations were lowered later. For male
rats, the high dose was w lowered to 1,280 ppm at two weeks, and
-------
ioxap.-e-e Mar-' 31, 1
-7-
to 640 pp- at 53 weeks after initiation of the study for an average
dose of 1,112 ppm. TVie low dose was similarly lowered to 640 pp~
after two weeks and 320 pp- 53 weeks after feeding had begun for ar,
average dose of 556 ppm. For female rats, both dose levels were
halved after 55 weeks, and average doses were calculated to be 540
and 1,080 ppm. For both sexes, toxaphene treatment was discontinued
after 60 weeks, and the animals were fed control diets without corn
oil for twenty weeks and then with corn oil for an additional 8
weeks. In male and female mice, both doses were halved 19 weeks
after treatment was initiated and average doses were 99 and 198
pprr,. Toxaphene treatment was discontinued after 80 weeks, and
animals were fed control diets without corn oil for 7 weeks then
diets with corn oil for an additional 3 to 4 weeks.
Although none of the tumors observed in the animals was uncommon for
the animal strain used, certain tumors and hyperplastic lesions were
present with higher incidence in the treated animals. In rats
these included thyroid follicular cell adenomas and carcinomas
(7/41 (17%) at the low dose; 9/35 (26%) at the high dose; and 1/7
(14%) in control males). Taking thyroid follicular cell adenomas
and carcinomas together, a statistically significant increase was
found for the high-dose group compared with the matched controls
for both male and female rats. Increased incidence of these lesions
was also significant in comparison with historical controls from
the same laboratory . In the female rats, there was also an elevated
cumulative incidence of tumors of the pituitary (chromophobe adenomas,
chromophobe carcinomas) in the high dose compared with the control
group.
In the mice, toxaphene was reported to be more toxic. Hepatocellular
carcinomas were observed with incidences of 69% and 98% in males at
the low and high doses, respectively, and at 10% and 69% in females
at the low and high doses, respectively. These neoplasms were not
observed in control animals of either sex, but hepatic nodules were
observed in 20% of matched-control males, but not in females. On
the basis of these findings, toxaphene was carcinogenic in B6C3Fi
mice and caused an increase incidence of thyroid tumors in Osborne-
Mendel rats.
V. QUANTIFICATION OF TOXICOLOGICAL EFFECTS
Health Advisories (HAs) are generally determined for One-day,. Ten-day,
Longer-term (approximately 7 years) and Lifetime exposures if adequate data
are available that identify a sensitive noncarcinogenic end point of toxicity.
The HAs for noncarcinogenic toxicants are derived using the following formula:
HA « (NOAEL or LOAEL) x (BW) . B_/L ( ug/L)
(UF) x ( L/day)
where:
NOAEL or LOAEL « No- or Lowest-Observed-Adverse-Effect-Level
in mg/kg bw/day .
-------
•Toxaphene March 3'., 1957
BW = assumed- body weight of a child (10 kg) or
an adult (70 kg).
UF = uncertainty factor (10, 100 or 1,000), in
accordance with NAS/ODW guidelines.
L/dav = assumed daily water consumption of a child
(1 L/day) or an adult (2 L/day).
One-day Health Advisory
The study by Lackey (1949) has been chosen to serve as the basis for calcu-
lating the One-day HA for toxaphene. This study reported convulsions in
dogs exposed to toxaphene at 5 mgAg/day for a few days (number not specified),
while 4 mg/kg/day induced only occasional convulsions even with much longer
exposures. Based on the author's statements, no convulsions were induced
in dogs after a single dose of 5 mg/kg bw, while 10 mg/kg induced convulsions
in 4/5 animals. Therefore, 5 mg/kg/day has been identified as the NOAEL.
for a single oral exposure to toxaphene.
The One-day HA for the 10 kg child is calculated as -follows -,---. . • . •- .
One-day HA = (S mg/kg/day) (10 kg) = 0.5 mg/L (500 ug/L)
(1 L/day) (100)
where:
5 mgAg/day = NOAEL for convulsions after a single oral dose of
toxaphene in dogs.
10 kg = assumed body weight of a child.
100 = uncertainty factor, chosen in accordance with NAS/ODW
guidelines for use with a NOAEL from an animal study.
1 L/day = Assumed daily water consumption of a child.
Ten-day Health Advisory
Results of the Lackey (1949) study suggest that the threshold if
toxicity for toxaphene nay be slightly lower in dogs than in rodents. In
that study, degeneration of the renal tubular epithelium and pyelitis
(inflammation of the renal pelvis) were reported in dogs exposed to toxaphene
at 4 mgA9 bw/day from 44 to 106 days. These effects were not observed at
higher doses in other species. It is uncertain from the study whether
these effects occurred within 10 days of exposure. Occasional convulsions
were also noted at 4 mgAg/day; therefore, this dose level is viewed as a
LOAEL for subchronic exposure to toxaphene*
Using the LOAEL of 4 mgAg/day, the Ten-day HA is calculated as follows:
Ten-day HA - (4 ngAq/day)(10 kg) „ 0.04 mg/L (40 ug/L)
(1000M1 L/day)
-------
rcxaphene March 3' , i?5?
-9-
4 ir.g/kg/day = LOAEL for kidney effects in dogs.
1 0 ko = assumed body weight of a child.
1000 = uncertainty factor, chosen in accordance with NAS/ODW
guidelines for use with a LOAEL from ar animal study.
1 L/day = assumed daily water consumption of a child.
Longer-term Health Advisory
A Longer-term HA has not been calculated due to the lack of appropriate
data.
Lifetime Health Advisory and DWEL
There are no acceptable studies in the available literature for
derivation of a lifetime DVfEL.
Evaluation of Carcinogenic Potential
0 Toxaphene may be classified in Group B: Probable Human Carcinogen,
according to EPA's proposed weight-of-evidence scheme for the
classification of carcinogenic potential. Because of this, caution
must exercised in making a decision on how to deal with possible
lifetime exposure to this substance. The risk manager must balance
this assessment of carcinogenic potential against the likelihood of
occurrence of health effects related to non-carcinogenic end-points
of toxicity. In order to assist the risk manager in this process,
drinking water concentrations associated with estimated excess
lifetime cancer risks over the range of one in ten thousand to one
in a million for the 70 kg adult, drinking 2 liters of water per day,
are provided.
0 Since the results of two bioassays (NCI, 1979; Litton Bionetics,
Inc., 1978) were positive for cancer induction, estimated risk
levels for toxaphene in drinking water can be calculated using the
linearized mulitstage model as discussed in the appendices to the
October Federal Register notice regarding the availability of Hater
Quality Criteria Documents (U.S. EPA, 1980).
0 Drinking water concentrations estimated to result in lifetime
excess cancer risks of 10~4, 10"^ and 10~6 for a 70 kg adult drinking
2 liters of water per day over a 70 year lifespan are 3.1 ug/L,
0.31 ug/L and 0.031 ug/L, respectively (upper 95% confidence limit).
0 The international Agency for Research on Cancer (IARC, 1979) has
placed toxaphene in category 2B, meaning that toxaphene is probably
carcinogenic in humans.
-------
ixapner.e Marc-
-10-
6 Applying the criteria described in EFA's guidelines for - assessment
of carcinogenic ristc (U.S. EPA, 1986), toxaphene may be classified
Group B2: Probable Human Carcinogen. This category is for agents
for which there is inadequate evidence fror. human studies and
sufficient evidence from animal studies.
VI. OTHER CRITERIA, GUIDANCE AND STANDARDS
0 A TWA of 500 ug/m3 and a tentative short-term exposure limit of 1.0
rng/mS have been set for toxaphene by ACGIH (1977).
The National Interim Primary Drinking Water Standard for toxaphene is
5 ug/L (U.S. EPA, 1976). •
The NAS (1977) estimated the ADI of toxaphene for humans at 1.25 ug/kg.
VII. ANALYTICAL METHODS
Determination of toxaphene is by a liquid-liquid extraction gas
chromatographic procedure (U.S. EPA, 1978; Standard Methods, 1985).
This procedure involves the use of 15% nethylene chloride in hexane
for sample extraction, followed by drying with anhydrous sodium
sulfate, concentration of the extract and identification by gas
chromatography. Detection and measurement is accomplished by
electron capture, microcoulometric or electrolytic conductivity
gas chromatography. Identification may be confirmed through the
use of gas chromatography-mass spectroscopy (GC-MS). The method
sensitivity is 0.001 to 0.010 ug/L for single component pesticides
and 0.050 to 1.0 ug/L for multiple component pesticides when
analyzing a 1-liter sample with the electron capture detector
(Holmstead et al., 1974).
VIII. TREATMENT TECHNOLOGIES
0 Treatment technologies with limited data for removal of toxaphene
from drinking water are adsorption by granular activated carbon
(GAC) and powdered activated carbon (PAC), air stripping and
coagulation/filtration. Other technologies adaptable to drinking
water systems might be able to remove toxaphene; however, such data
are not readily available.
'• • . ,'t-* /•
0 GAC columns mounted in a mobile unit have been used for the treatment
of hazardous waste spills. This unit proved to be 97% effective in
removing toxaphene from pond water in Virginia from an initial
concentration of 36 ug/L. The GAC columns, with a contact time of
26 minutes, treated the water at a rate of 70,000 gpd.
• Another study examined the effectiveness of PAC for the removal of
several fish poisons, including toxaphene. PAC was added to water
containing 0.3 mg/L of toxaphene. Toxaphene removals of 95% were
achieved at a carbon dosage of 9 mg/L. . The results of this experiment
indicate that PAC is effective for toxaphene removal (U.S. EPA, 1985b)
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•loxapherse March 3', 195'
-1 1 -
A theoretical nodel of an air stripping colue.-i was developed and
applied to the removal of some synthetic organic chemicals (SOC)
including toxaphene. The mass transfer coefficients for each SOC
were developed according to Perry and Chilton (1973). The results
show that toxaphene was 99% theoretically removed at an air-to-wate:
ratio of 30. Actual air stripping performance data for removal of
toxaphene are not readily available.
Air stripping is a simple and relatively inexpensive process for
removing organics from water. However, use of this process then
transfers the contaminant directly to the air stream. When consid-
ering use of air stripping as a treatment process, it is suggested
that careful consideration be given to the overall environmental
occurrence, fate, route of exposure, and various hazards associated
with the chemical.
A conventional water treatment plant consisting of coagulation, sed:
mentation and filtration reportedly had little effect on reducing
toxaphene from water. The influent toxaphene concentrations did
not exceed 0.41 ug/L (U.S. EPA, 1985b).
Treatment technologies for the removal of toxaphene from drinking
water have not been extensively evaluated except on an experimental
level. Individual or combinations of technologies selected for
toxaphene reduction must be based on a case-by-case technical
evaluation, and an assessment of the economics involved.
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Toxaphene March 3', 19£~
-12-
IX. REFERENCES
ACGIH. 1977. American Conference of Governmental Industrial Hygienists.
TLVs: Threshold limit values for chemical substances and physical agents
in the workroom environment with intended changes for 1977. Cincinnati, Or
Allen, A.L., L.D. Roller and G.A. Pollack. 1983. Effect of toxaphene exposure
on immune responses in mice. J. Toxicol. Environ. Health 11:61-69.
Boots Hercules Agrochemicals. Not dated. Boots Hercules toxaphene insecticide
summary of toxicological investigations. Bulletin T-105D.
Boyd, E.K., and F.I. Taylor. 1971. Toxaphene toxicity in protein-deficient
rats. Toxicol. Appl. Pharmacol. 18:158-167.
Chandurkar, P.S., and F. Matsumura. 1979. Metabolism of toxaphene components
in rats. Arch. Environ. Contam. Toxicol. 8:1-24.
Chernoff, N., and B.D. Carver. 1976. Fetal toxicity of toxaphene in rats
and mice. Bull. Environ. Contam. Toxicol. 15:660-664.
Clapp, K.L., D.M. Nelson, J.T. Bell et al. 1971. A study of the effects
of toxaphene on the hepatic cells of rats. In; Proc. Ann. Meet.
Western Section, An. Soc. Anim. Sci. 22:313-323.
Crowder, L.A., and E.F. Dindal. 1974. Fate of 36d-toxaphene in rats. '
Bull. Environ. Contam. Toxicol. 12:320-327.
Fitzhugh, O.G., and A.A. Nelson. 1951. Comparison of chronic effects
produced in rats by several chlorinated hydrocarbon insecticides.
Fed. Proc. 10:295.
Hayes, w.j. 1975. Toxicology of pesticides. Williams and Wilkins Co.
Baltimore, MD.
Hill, R.M. 1977. Memorandum to Fred Hageman. December 15. (U.S. EPA).
Holmstead, R.L., S. Khalifa and J.E. Casida. 1974. Toxaphene composition
analyzed by combined gas chromatography-chemical ionization mass
spectrometry. J. Agric. Food Chem. 22:939-944.
ZARC. 1979. International Agency for Research on Cancer. Toxaphene (poly-
chlorinated camphenes). IARC monograph* on the evaluation of the
carcinogenic risk of chemicals to humans. 20:327-348.
IUPAC. 1979. International Union of Pure and Applied Chemistry. IUPAC
Reports on pesticides. 7. Toxaphene (camphechlor). A special report.
Pure Appl. Chem. 51:1583-1601.
Lackey, R.W. 1949. Observations on the acute and chronic toxicity of
toxaphene in the dog. J. Ind. Hyg. Toxicol. 31:117-120.
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^oxaphene March 31, 19E'
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Lehman, A.J. 1951. Chemicals in foods: A report to the Association of
Food and Drug Officials on current, developments. Part II. Pesticides.
Q. Bull. Assoc. Food Drug Off. U.S. 15:122-133.
Lehman, A.J. 1952. Oral toxicity of toxaphene. Q* Bull. Assoc. Food Drug
Off. U.S. 16:47.
Lehman, A.J. 1959. Appraisal of the safety of chemicals ir. foods, drugs
and cosmetics. 0,. Bull. Assoc. Food Drug Off. U.S.
Litton Bionetics, Inc. 1978. Carcinogenic evaluation in mice. Toxaphene.
Final rep. LSI Project No. 20602, Kensington, MD. Submitted to
Hercules, Inc., Wilmington, DE.
McGee, L.C., H.L. Reed and J.P. Fleming. 1952. Accidental poisoning by
toxaphene. J. Amer. Med. Assoc. 149:1124-1125.
Meister, R.T., ed. 1967. Farm chemicals handbook. Willoughby, OH: Meister
Publishing Company.
NCI. 1979. National Cancer Institute. Bioassay of toxaphene for possible
carcinogenesis. NCI Carcinogenesis Tech. Rep. Ser. No. 37, DHEW Publ.
No. (NIH) 79-837.
NAS. 1977. National Academy of Sciences. Safe Drinking Water Committee.
Drinking Water and Health. Volume 1. National Academy Press. Washington,
D.C.
NTP. 1983. National Toxicology Program. Annual plan for Fiscal Year 1983.
NTP-82-119. p. 66.
Ohsawa, T., J.R. Knox, S. Khalifa et al. 1975. Metabolic dechlorination
of toxaphene in rats* J. Agric. Food Chem. 23:98-103.
Perry, R.H., and C.H. Chilton. 1973. Chemical Engineers Handbook. 5th
Edition. McGraw Hill Book Company.
Pollock, G.A., and R. Hillatrand. 1962. The elimination, distribution and
metabolism of 1*C-toxaphene in the pregnant rat. J. Environ. Sci.
Health. 817:635-646.
Pollock, G.A., and W.W. Kilgore. 1976a. Toxaphene. Residue Rev. 69:87-140.
Pollock, G.A., and W.W. Kilgore. 1976b. Die metabolism and excretion of
toxaphene and selected toxaphene fractions. Toxicol. Appl. Pharmacol.
45:235.
Saleh, M.A., W.V. Turner and J.E. Casida. 1977. Polychlorobornane components
of toxaphene: Structure-toxicity relations and metabolic reductive
dechlorination. Science 196:1256-1258.
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-oxapnene March 3
-14- -
Standard Methods. 1985. Method 509A. Organochlorine Pesticides, Standard
Methods for the Examination of Water and Wastewater, 16th Edition,
APHA, AWVA, KPCF, 1985.
U.S. EPA. 1976. U.S. Environmental Protection Agency. National interi-
primary drinking water regulations. Office of Water Supply.
EPA-57C/9-76-003.
U.S. EPA. 1978. U.S. Environmental Protection Agency. Method for organo-
chlorine pesticides in drinking water. Methods for organochlorine
pesticides and chlorophenoxy acid herbicides in drinking water and raw
source water. Interim. July 1978.
U.S. EPA. 1980. U.S Environmental Protection Agency. Water quality
criteria documents: Availability. Fed. Reg. 45:79340-79341.
U.S. EPA. 1983. U.S. Environmental Protection Agency. Occurrence of
pesticides in drinking water, food, and air. Office of Drinking
Water.
U.S. EPA. 1985a. U.S. Environmental Protection Agency. Draft health
effects criteria document for toxaphene. Office of Drinking Water.-
U.S. EPA. 1985b. U.S. Environmental Protection Agency. Draft technologies
and costs for the removal of synthetic organic chemicals from potable
water supplies. Science and Technology Branch, CSD, ODW, Washington,
D.C.
U.S. EPA. 1986. U.S. Environmental Protection Agency. Guidelines for car-
cinogen risk assessment. Fed. Reg. 51(185):33992-34003. September 24.
U.S. FDA. 1984. U.S. Food and Drug Administration. Surveillance Index
for Pesticides. Bureau of Foods.
Windholz, M. 1983. The Merck Index. 10th Edition. Merck and Co., Inc.,
Rahway, N.J.
Zweig, G., E.L. Pye, R. Sitlani, et al. 1963. Residues in milk from dairy
cows fed low levels of toxaphene in their daily ration. J. Agric. Food
Chem. 11:70-72.
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~N;TED STATES ENVIRONMENTAL PROTECTION AGIV.CY
VVASH.'.NGTCN'. D.C. 20460
OFFICE OF TCX.C iJ3£TA.\C£5
NOV
TO: Registrants cf Produces Containing 2,4,5-T and/or Si 1 vex
5y certified letter dated Marcn 22, 1979 you were infcr~£j cf
the suspension action ta.
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NON-SUSPENDED USES
SILVEX
:= Rice
igelan:: . , Rangeland
'ports Sugarcane
leecerows (net otherwise Preharvest fruit crop of apples.
induced in suspended uses,: e. g. prunes and pears
rights-of-way, pasturef"" Fence rows, hedgerows, -"ences
Lumberyards . (not otherwise included in
Refineries suspended uses, e.g., rignts-
Nonfooc crops of way, pasture, home and
Storage areas garden)
Noncrop areas Nonfood crop areas
'.'Jaste7 ands (not otherwise included Noncrop areas
in suspencec uses, e.g., forestry) Storage areas
its Vacant lots, parking areas, etc.
:rial sites and areas 'not Industrial sites or bui -dings(not
icrv.-ise included in suspenses otherwise included in suspend;
e.g., richts-of way) uses, e.g., rights-o-'-v/ay,
ccmmercia!/ornamental turf)
n uses of 2,-,5-T were suspended and cancelled in 157C. ?. R.
-11, ^pril 20, 1970, suspended the registrations fcr products
containing 2,4.5-7 and bearing directions for all use^ in lakes, penes,
ano ditcr.bc.n:.'hose labeling could be modified by deleting such claims.
7hcse registrants who submitted amended labeling which deleted the uses
now considered as non-suspended may, if they so choose, submit applica-
tions for amended registration vvh.ich restore-those uses tc the labeling.
Offer-to-pay statements anc method of support forms will not be required
if the registrant restores the non-suspended uses which were on his
Tabel immediately prior to the suspensions announcement. If the
registrant elects to add additional non-suspended uses, method of support
and offer to pay statements will be .required since such applications are
subject to 3 (c)(i)(0) provisions of the Act.
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