Federal Register / Vol. 81, No. 1 / Monday, January 4, 2016 / Rules and Regulations 13 

person listed in the FOR FURTHER

INFORMATION CONTACT section to 

coordinate protest activities so that your 

message can be received without 

jeopardizing the safety or security of 

people, places or vessels. 

List of Subjects in 33 CFR Part 165 

Harbors, Marine safety, Navigation 

(water), Reporting and recordkeeping 

requirements, Security measures, and 

Waterways. 

For the reasons discussed in the 

preamble, the Coast Guard amends 33 

CFR part 165 as follows: 

PART 165—REGULATED NAVIGATION 

AREAS AND LIMITED ACCESS AREAS 

■ 1. The authority citation for part 165 

continues to read as follows: 

Authority: 33 U.S.C. 1231; 50 U.S.C. 191; 

33 CFR 1.05–1, 6.04–1, 6.04–6, and 160.5; 

Department of Homeland Security Delegation 

No. 0170.1. 

■ 2. Add § 165.T08–1086 to read as 

follows: 

§ 165.T08–1086 Safety Zone; Intracoastal 

Waterway; Lake Charles, LA. 

(a) Location. The following area is a 

safety zone: all waters of the Intracoastal 

Waterway (ICW) extending 100-yards 

east and west of ICW Mile Marker 244.5 

located at position 30°03′38′′ N. 

093°22′19′′ W., Lake Charles, Louisiana. 

The coordinates are based on (NAD 83). 

(b) Effective periods. This rule is 

effective from 7 a.m. on January 4, 2016 

through 6 p.m. on January 14, 2016. 

This rule will be enforced when 

personnel and equipment are on scene 

and conducting working on electrical 

lines. 

(c) Regulations. (1) Under the general 

safety zone regulations in § 165.23 of 

this part, entry into this zone is 

prohibited to all vessels except those 

vessels specifically authorized by the 

Captain of the Port, Port Arthur or a 

designated representative. 

(2) Persons or vessels requiring entry 

into or passage through must request 

permission from the Captain of the Port, 

Port Arthur, or a designated 

representative. They may be contacted 

on VHF Channel 13 or 16, or by 

telephone at (337) 912–0073. 

(3) All persons and vessels shall 

comply with the lawful orders or 

directions given to them by the Captain 

of the Port, Port Arthur or the Captain 

of the Port’s designated representative. 

On-scene U.S. Coast Guard patrol 

personnel include commissioned, 

warrant, and petty officers of the U.S. 

Coast Guard. 

(d) Information broadcasts. The Coast 

Guard will inform the public through 

broadcast notices to mariners of the 

enforcement periods for the safety zone 

as well as any changes in the schedule. 

Dated: December 15, 2015. 

R.S. Ogrydziak, 

Captain, U.S. Coast Guard, Captain of the 

Port, Port Arthur, Texas. 

[FR Doc. 2015–33072 Filed 12–31–15; 8:45 am] 

BILLING CODE 9110–04–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 141 

[EPA–HQ–OW–2012–0155; FRL–9940–64– 

OW] 

Announcement of Final Regulatory 

Determinations for Contaminants on 

the Third Drinking Water Contaminant 

Candidate List 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final regulatory determinations. 

SUMMARY: The U.S. Environmental 

Protection Agency (EPA) is announcing 

final regulatory determinations not to 

issue national primary drinking water 

regulations for four of the 116 

contaminants listed on the Third 

Contaminant Candidate List. The Safe 

Drinking Water Act, as amended in 

1996, requires the EPA to make 

regulatory determinations every five 

years on at least five unregulated 

contaminants. A regulatory 

determination is a decision about 

whether or not to begin the process to 

propose and promulgate a national 

primary drinking water regulation for an 

unregulated contaminant. On October 

20, 2014, the agency published its 

preliminary determinations not to 

regulate dimethoate, 1,3-dinitrobenzene, 

terbufos, terbufos sulfone and begin the 

process to regulate strontium. The 

agency requested public comment on 

the determinations, process, rationale 

and supporting technical information. 

The agency received comments from 14 

individuals or organizations on the 

preliminary regulatory determinations. 

After careful review and consideration 

of the public comments, the agency is 

making a final determination not to 

regulate dimethoate, 1,3-dinitrobenzene, 

terbufos and terbufos sulfone. The 

agency, however, is delaying the final 

regulatory determination on strontium 

in order to consider additional data and 

decide whether there is a meaningful 

opportunity for health risk reduction by 

regulating strontium in drinking water. 

DATES: In accordance with 40 CFR 23.7 

for purposes of judicial review, the 

regulatory determinations in this 

document are issued as of January 4, 

2016. 

FOR FURTHER INFORMATION CONTACT: 

Zeno Bain, Standards and Risk 

Management Division, Office of Ground 

Water and Drinking Water, Office of 

Water (Mailcode 4607M), 

Environmental Protection Agency, 1200 

Pennsylvania Ave. NW., Washington, 

DC 20460; telephone number: (202) 

564–5970; email address: bain.zeno@

epa.gov. For general information, 

contact the Safe Drinking Water Hotline, 

telephone number: (800) 426–4791. The 

Safe Drinking Water Hotline is open 

Monday through Friday, excluding legal 

holidays, from 10 a.m. to 4 p.m., eastern 

time. 

SUPPLEMENTARY INFORMATION: 

I. General Information 

A. Does this action apply to me? 

These final regulatory determinations 

will not impose any requirements on 

anyone. Instead, this action notifies 

interested parties of the EPA’s final 

regulatory determinations for four 

contaminants and provides a summary 

of the major comments received on the 

October 20, 2014, preliminary 

determinations (USEPA, 2014c). 

B. How can I get copies of this document 

and other related information? 

Docket: The EPA has established a 

docket for this action under Docket ID 

No. EPA–HQ–OW–2012–0155. Publicly 

available docket materials are available 

either electronically at http://

www.regulations.gov or in hard copy at 

the Water Docket, EPA/DC, EPA West, 

Room 3334, 1301 Constitution Ave. 

NW., Washington, DC. The Water 

Docket Public Reading Room is open 

from 8:30 a.m. to 4:30 p.m., Monday 

through Friday, excluding legal 

holidays. The telephone number for the 

Public Reading Room is (202) 566–1744, 

and the telephone number for the Water 

Docket is (202) 566–2426. 

Electronic Access: You may access 

this Federal Register document 

electronically from the Government 

Printing Office under the ‘‘Federal 

Register’’ listings at http://

www.gpo.gov/fdsys/browse/

collection.action?collectionCode=FR. 

Abbreviations Used in This Document 

CCL Contaminant Candidate List 

CCL 3 Third Contaminant Candidate List 

CFR Code of Federal Regulations 

EPA Environmental Protection Agency 

FR Federal Register 

HRL Health Reference Level 

MCL Maximum Contaminant Level 

MCLG Maximum Contaminant Level Goal 

MRL Minimum Reporting Limit 


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14 Federal Register / Vol. 81, No. 1 / Monday, January 4, 2016 / Rules and Regulations 

1The MCLG is the ‘‘maximum level of a 

contaminant in drinking water at which no known 

or anticipated adverse effect on the health of 

persons would occur, and which allows an 

adequate margin of safety. Maximum contaminant 

level goals are nonenforceable health goals’’ (40 

CFR 141.2). 

2An NPDWR is a legally enforceable standard 

that applies to public water systems. An NPDWR 

sets a legal limit (called a maximum contaminant 

level or MCL) or specifies a certain treatment 

technique for public water systems for a specific 

contaminant or group of contaminants. 

3The statute authorizes up to a nine-month 

extension of this promulgation date. 

NPDWR National Primary Drinking Water 

Regulation 

PWS Public Water System 

RD Regulatory Determination 

RD 3 Third Regulatory Determination 

RSC Relative Source Contribution 

SDWA Safe Drinking Water Act 

STORET Storage and Retrieval Data System 

UCMR Unregulated Contaminant 

Monitoring Regulation 

UCMR 1 First Unregulated Contaminant 

Monitoring Regulation 

UCMR 2 Second Unregulated Contaminant 

Monitoring Regulation 

UCMR 3 Third Unregulated Contaminant 

Monitoring Regulation 

USDA United States Department of 

Agriculture 

USGS United States Geological Survey 

mg/L micrograms per Liter 

Table of Contents 

I. General Information 

A. Does this action apply to me? 

B. How can I get copies of this document 

and other related information? 

II. Purpose and Background 

A. What is the purpose of this action? 

B. What are the statutory requirements for 

the Contaminant Candidate List (CCL) 

and regulatory determinations? 

C. What contaminants did the EPA 

consider for regulations? 

III. What process did the EPA use to make 

the regulatory determinations? 

IV. Summary of the EPA’s Findings on the 

Four Contaminants With Final 

Regulatory Determinations 

A. Dimethoate 

1. Description 

2. Agency Findings 

B. 1,3-Dinitrobenzene 

1. Description 

2. Agency Findings 

C. Terbufos and Terbufos Sulfone 

1. Description 

2. Agency Findings 

D. Public Comments on Four Contaminants 

With Final Regulatory Determinations 

V. Summary of Public Comments on 

Strontium and the Agency’s Responses 

A. Background on Strontium and the EPA’s 

Preliminary Determination 

B. What comments did the EPA receive on 

strontium? 

VI. Next Steps 

VII. References 

II. Purpose and Background 

A. What is the purpose of this action? 

The purpose of this action is to 

present a summary of the EPA’s findings 

related to the final regulatory 

determinations for four contaminants 

listed on the Third Contaminant 

Candidate List (CCL 3) (USEPA, 2009). 

The four contaminants include: 

Dimethoate, 1,3-dinitrobenzene, 

terbufos and terbufos sulfone. Today’s 

action briefly summarizes the statutory 

requirements for targeting drinking 

water contaminants for regulatory 

determination, provides an overview of 

the contaminants the agency considered 

for regulation and describes the 

approach used to make the final 

regulatory determinations. In addition, 

today’s action summarizes the public 

comments received on the agency’s 

preliminary determinations and the 

agency’s responses to those comments, 

including the status of the EPA’s 

evaluation of strontium. 

B. What are the statutory requirements 

for the Contaminant Candidate List 

(CCL) and regulatory determinations? 

The specific statutory requirements 

for the CCL and regulatory 

determinations can be found in the Safe 

Drinking Water Act (SDWA), section 

1412(b)(1). The 1996 SDWA 

Amendments require the EPA to publish 

the CCL every five years. The CCL is a 

list of contaminants that are not subject 

to any proposed or promulgated 

national primary drinking water 

regulations (NPDWRs), are known or 

anticipated to occur in public water 

systems (PWSs) and may require 

regulation under SDWA. The 1996 

SDWA Amendments also direct the 

agency to determine whether to regulate 

at least five contaminants from the CCL 

every five years. SDWA requires the 

agency to publish a Maximum 

Contaminant Level Goal (MCLG) 1 and 

promulgate an NPDWR2 for a 

contaminant if the Administrator 

determines that: 

(a) The contaminant may have an 

adverse effect on the health of persons; 

(b) The contaminant is known to 

occur or there is a substantial likelihood 

that the contaminant will occur in 

public water systems with a frequency 

and at levels of public health concern; 

and 

(c) In the sole judgment of the 

Administrator, regulation of such 

contaminant presents a meaningful 

opportunity for health risk reduction for 

persons served by public water systems. 

If the agency determines that all three 

of these statutory criteria are met, it 

makes a determination that a national 

primary drinking water regulation is 

needed. In that case, the agency has 24 

months to publish a proposed MCLG 

and NPDWR. After the proposal, the 

agency has 18 months to publish a final 

MCLG and promulgate a final NPDWR 

(SDWA section 1412(b)(1)(E)).3

C. What contaminants did the EPA 

consider for regulation? 

On October 20, 2014, the EPA 

published preliminary regulatory 

determinations for five contaminants on 

the third Contaminant Candidate List 

(CCL 3) that had sufficient information 

to support a regulatory determination 

(USEPA, 2014c). The five contaminants 

are 1,3-dinitrobenzene, dimethoate, 

terbufos, terbufos sulfone and 

strontium. The agency is making final 

regulatory determinations not to 

regulate dimethoate, 1,3-dinitrobenzene, 

terbufos and terbufos sulfone. The 

agency is not making a final regulatory 

determination for strontium at this time. 

The agency’s decision to delay a final 

determination for strontium is based on 

public comments received and the plan 

to further evaluate scientific information 

that became available after publication 

of the preliminary regulatory 

determinations. The agency is currently 

conducting additional scientific 

analyses to determine if there is a need 

to develop a national drinking water 

regulation for strontium. For more 

information about the comments the 

agency received on strontium and the 

analyses that are underway, see section 

V.A of this notice. 

Information on the five contaminants 

can be found in the Regulatory 

Determinations 3 Support Document 

(USEPA, 2014b). More information is 

available at the Water Docket (Docket ID 

No. EPA–HQ–OW–2012–0155) and also 

on EPA’s Regulatory Determination 3 

Web site at http://www2.epa.gov/ccl/

regulatory-determination-3. 

III. What process did the EPA use to 

make the regulatory determinations? 

This section gives a summary of the 

regulatory determination process the 

agency followed to identify and evaluate 

contaminants for the Third Regulatory 

Determination. For more detailed 

information on the process and the 

analyses performed, please refer to the 

‘‘Protocol for the Regulatory 

Determination 3’’ document (USEPA, 

2014a) and the Federal Register notice 

for the Preliminary Regulatory 

Determinations for Contaminants on 

CCL 3 (USEPA, 2014c). 

The CCL 3 identified 116 

contaminants that are currently not 

subject to any proposed or promulgated 

national drinking water regulation, are 

known or anticipated to occur in public 

water systems, and may require 


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4The non-CCL 3 contaminants, N-Nitroso-di-nbutylamine (NDBA) and NNitrosomethylethylamine (NMEA), were included 

because they are part of a larger group 

(nitrosamines) that also includes a number of CCL 

3 contaminants. 

regulation under SDWA (USEPA, 2009). 

Since some of the CCL 3 contaminants 

do not have adequate health and/or 

occurrence data to evaluate against the 

three statutory criteria (see section II.B 

of this notice), the agency used a threephase process to identify which of the 

contaminants are candidates for 

regulatory determinations. Priority was 

given to identifying contaminants 

known to occur or with substantial 

likelihood to occur at frequencies and 

levels of public health concern. 

The three phases of the Third 

Regulatory Determination process are 

(1) the Data Availability Phase, (2) the 

Data Evaluation Phase and (3) the 

Regulatory Determination Assessment 

Phase. The overall process is displayed 

in Exhibit 1. 

BILLING CODE 6560–50–P 

BILLING CODE 6560–50–C 

The purpose of the first phase, the 

Data Availability Phase, is to determine 

if the agency ‘‘may have’’ sufficient data 

to characterize the potential health 

effects and known or likely occurrence 

in drinking water. Although 

contaminants must have sufficient data 

to evaluate the statutory criteria in 

Phase 3, the agency does not want to 

rule out any contaminants too early in 

the process; therefore, if sufficient 

health and occurrence data are likely 

available, the contaminants are 

considered in the Data Evaluation 

Phase, the second phase of the 

regulatory determination process. From 

the 116 CCL 3 contaminants, the agency 

identified 37 contaminants (35 CCL 3 

contaminants and two non-CCL 3 

contaminants 4) to further evaluate in 

the second phase. 

During the second phase, the agency 

further evaluates each contaminant on 

the short list to identify those that have 

sufficient data (or are expected to have 

sufficient data within the timeframe 

allotted for the second phase) for the 

EPA to assess the three statutory 

criteria. As part of the second phase, the 

agency specifically focuses its efforts on 

identifying those contaminants or 

contaminant groups that are occurring 

or have substantial likelihood to occur 

at levels and frequencies of public 

health concern, based on the best 

available peer reviewed data. If the 

agency finds that sufficient data are not 

available or not likely to be available to 

evaluate the three statutory criteria 

during the first and second phases, then 

the contaminant is not considered a 

candidate for making a regulatory 

determination. 

If sufficient data are available for a 

contaminant to characterize the 

potential health effects and known or 

likely occurrence in drinking water, the 

contaminant is evaluated against the 

three statutory criteria in the Regulatory 

Determination Assessment Phase, 

which is the third phase of the process. 

Of the 37 contaminants that were 

evaluated under Phase 2, 12 were 

designated for further evaluation in 

Phase 3. 


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16 Federal Register / Vol. 81, No. 1 / Monday, January 4, 2016 / Rules and Regulations 

5HRLs are risk derived concentrations against 

which to evaluate the occurrence data to determine 

if contaminants may occur at levels of public health 

concern. They are not the level of a contaminant in 

drinking water that must not be exceeded to protect 

any particular population (i.e., an HRL is not an 

MCL). 

Of the 12 contaminants that were 

evaluated in Phase 3, the agency did not 

make preliminary regulatory 

determinations for seven contaminants. 

The seven contaminants include 

chlorate and six nitrosamines. Chlorate 

and the six nitrosamines are 

disinfection byproducts, and the agency 

is further evaluating these contaminants 

as part of the regulatory review of 

existing Microbial and Disinfection 

Byproduct regulations, as announced in 

the Preliminary Regulatory 

Determination 3 Federal Register notice 

published on October 20, 2014 (USEPA, 

2014c). 

After evaluating the five remaining 

CCL 3 contaminants (dimethoate, 1,3- 

dinitrobenzene, terbufos, terbufos 

sulfone and strontium) against the three 

statutory criteria and considering other 

relevant information (such as level and 

frequency of occurrence, population 

exposed and information on sensitive 

populations and lifestages), the agency 

made preliminary regulatory 

determinations to regulate strontium 

and to not regulate the remaining four 

contaminants. These preliminary 

determinations, with their supporting 

analyses and documentation, were 

published in the Federal Register on 

October 20, 2014, for public comment 

(USEPA, 2014c). 

The EPA received comments from 14 

organizations and individuals on the 

October 20, 2014, Federal Register 

notice. These 14 organizations and 

individuals include four environmental 

organizations, six industry groups, one 

state association and three anonymous 

individuals. The agency prepared a 

Response to Comments document for 

this action that is available in the Public 

Docket at www.regulations.gov under 

Docket ID No. EPA–HQ–OW–2012– 

0155. Comments on specific 

contaminants, and the EPA’s responses, 

are briefly summarized in the sections 

below. 

IV. Summary of the EPA’s Findings on 

the Four Contaminants With Final 

Regulatory Determinations 

After considering the public 

comments, the EPA is making final 

regulatory determinations not to 

regulate dimethoate, 1,3-dinitrobenzene, 

terbufos and terbufos sulfone. 

This notice provides a brief 

description of the agency findings on 

these contaminants. Details on the 

background, health and occurrence 

information and analyses used to 

evaluate and make final determinations 

for these contaminants can be found in 

the Regulatory Determinations 3 

Support Document (USEPA, 2015b) and 

the Federal Register notice for the 

Preliminary Regulatory Determination 3 

(USEPA, 2014c). 

For each contaminant, the agency 

evaluated the available human and 

toxicological data, derived a health 

reference level (HRL),5 evaluated the 

potential and/or likely occurrence and 

examined the likely exposed population 

for the contaminant in public water 

systems. The agency also considered 

whether information was available on 

sensitive populations. The agency used 

the findings from these evaluations to 

determine whether the three SDWA 

statutory criteria are satisfied. Table 1 

gives a summary of the health and 

occurrence information for the four 

contaminants with final determinations 

under RD 3. 

TABLE 1—SUMMARY OF THE HEALTH AND OCCURRENCE INFORMATION AND THE FINAL DETERMINATIONS FOR FOUR OF

THE CONTAMINANTS CONSIDERED FOR RD 3 

RD 3 

contaminants 

Health 

reference 

level 

(HRL) 

(μg/L) 

Occurrence findings from primary data sources 

Final 

Primary determination 

database 

PWSs with at least 1 

detection ≥1⁄2 HRL 

Population served by 

PWSs with at least 1 

detection ≥1⁄2 HRL 

PWSs with at least 1 

detection ≥HRL 

Population served by 

PWSs with at least 1 

detection ≥HRL 

Dimethoate .... 15.4 UCMR 2 ... 0% (0 of 4140) .......... 0% (0 of 229M) .............. 0% (0 of 4140) .......... 0% (0 of 229M) .............. Do not regulate. 

1,3- 

Dinitrobenzene.

0.7 UCMR 2 ... 0% (0 of 4139) .......... 0% (0 of 229M) .............. 0% (0 of 4139) .......... 0% (0 of 229M) .............. Do not regulate. 

Terbufos ........ 0.35 UCMR 1 ... 0% (0 of 295) ............ 0% (0 of 41M) ................ 0% (0 of 295) ............ 0% (0 of 41M). ............... Do not regulate 

Terbufos 

sulfone.

0.35 UCMR 2 ... 0.02% (1 of 4140) ..... 0.01% (44.6K of 229M) .. 0.02% (1 of 4140) ..... 0.01% (44.6K of 229M) .. Do not regulate. 

A. Dimethoate 

1. Description 

Dimethoate is an organophosphate 

pesticide, commonly used as an 

insecticide on field crops (e.g., wheat, 

alfalfa, corn and cotton), orchard crops, 

vegetable crops and in forestry. 

Synonyms for dimethoate include 

dimethogen, dimeton, dimevur and 

cygon (HSDB, 2010; USEPA, 2007). 

Dimethoate is considered highly mobile 

and relatively non-persistent in the 

environment (USEPA, 2007). 

2. Agency Findings 

The agency is making a determination 

not to regulate dimethoate with an 

NPDWR. It does not occur at levels and 

frequencies of public health concern. As 

a result, the agency finds that an 

NPDWR does not present a meaningful 

opportunity for health risk reduction. 

The primary data for dimethoate are 

the 2008–2010 nationally representative 

drinking water monitoring data, 

generated through the EPA’s Second 

Unregulated Contaminant Monitoring 

Regulation (UCMR 2). Dimethoate was 

not detected in any of the 32,150 UCMR 

2 samples collected by 4,140 PWSs 

(serving ∼230 million people) at levels 

greater than the 1⁄2 HRL (7.7 mg/L), the 

HRL (15.4 mg/L), or the minimum 

reporting level (MRL) (0.7 mg/L) 

(USEPA, 2015c). Based on the results of 

the UCMR 2 samples, the estimated 

population exposed to dimethoate at 

levels of public health concern is 0%. 

Other supplementary sources of 

finished water data from the State of 

California, the U.S. Department of 

Agriculture (USDA) and the U.S. 

Geologic Survey (USGS) indicate that 

the occurrence of dimethoate in PWSs is 

likely to be low to non-existent. 

Dimethoate occurrence data for ambient 

water from the USGS and the Storage 

and Retrieval (STORET) Data System are 

consistent with those for finished water. 

These data sources are discussed in the 

October 2014 Federal Register notice of 

the Preliminary Regulatory 

Determination 3 (USEPA, 2014c). 


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B. 1,3-Dinitrobenzene 

1. Description 

1,3-Dinitrobenzene is a nitro aromatic 

compound that is used as an industrial 

chemical and formed as a by-product in 

the manufacture of munitions, as well as 

in the production of other substances 

(HSDB, 2009). There are no known 

natural sources of 1,3-dinitrobenzene. 

1,3-Dinitrobenzene appears to be 

moderately persistent in environmental 

media and moderately mobile in soil 

and water, although in soils with high 

clay content it will be less mobile 

(USEPA, 2015b). 

2. Agency Findings 

The agency is making a determination 

not to regulate 1,3-dinitrobenzene with 

an NPDWR. It does not occur at levels 

and frequencies of public health 

concern. As a result, the agency finds 

that an NPDWR does not present a 

meaningful opportunity for health risk 

reduction. 

The primary data for 1,3- 

dinitrobenzene are the 2008–2010 

nationally representative drinking water 

monitoring data generated through the 

EPA’s UCMR 2 (USEPA, 2015c). UCMR 

2 is the only dataset with finished water 

data for this contaminant. UCMR 2 

collected 32,152 samples from 4,139 

PWSs for 1,3-dinitrobenzene and it was 

not detected above the MRL (0.8 mg/L), 

which is only slightly higher than the 

HRL (0.7 mg/L). Based on the results of 

the UCMR 2 samples, the estimated 

population exposed to 1,3- 

dinitrobenzene at or above the MRL is 

0%. 

Findings from the available ambient 

water data for 1,3-dinitrobenzene are 

consistent with the results in finished 

water. Ambient water data in STORET 

included no measured results above 

0.33 mg/L in 143 samples from 70 sites 

(USEPA, 2012). It should be noted that 

some occurrence above the HRL may 

have gone undetected since reporting 

levels are not documented. These data 

sources are discussed in the October 

2014 Federal Register notice of the 

Preliminary Regulatory Determination 3 

(USEPA, 2014c). 

C. Terbufos and Terbufos Sulfone 

1. Description 

Terbufos is a phosphorodithioate 

pesticide (i.e., an organophosphate) 

used as an insecticide-nematicide to 

control a variety of insect pests, 

primarily used on corn and sugar beets 

(USEPA, 2006). Terbufos sulfone is a 

degradate of terbufos. Total toxic 

residues of terbufos and degradates are 

highly mobile and persistent in the 

environment, with terbufos sulfone 

being more mobile and substantially 

more persistent than terbufos (USEPA, 

2006). 

2. Agency Findings 

The agency is making determinations 

not to regulate terbufos and terbufos 

sulfone with NPDWRs. They do not 

occur at levels and frequencies of public 

health concern. As a result, the agency 

finds that an NPDWR does not present 

a meaningful opportunity for health risk 

reduction. 

The primary data for terbufos are from 

the First Unregulated Contaminant 

Monitoring Regulation (UCMR 1) 

screening survey (2001–2003) (USEPA, 

2008). The UCMR 1 screening survey 

collected 2,301 finished water samples 

from 295 PWSs for terbufos and it was 

not detected at levels at or above the 

MRL (0.5 mg/L), which is slightly higher 

than the HRL (0.35 mg/L) (USEPA, 

2008). Based on the results of the UCMR 

1 screening survey, the estimated 

population exposed to terbufos at or 

above the MRL is 0%. 

The primary data for terbufos sulfone 

are nationally representative finished 

water monitoring data generated 

through the EPA’s UCMR 2 (2008–2010) 

(USEPA, 2015c). UCMR 2 collected 

32,149 finished water samples from 

4,140 PWSs (serving ∼230 million 

people) for terbufos sulfone and it was 

detected in only one sample, at a 

concentration of 0.42 mg/L. The MRL is 

0.4 mg/L, which is slightly higher than 

the HRL (0.35 mg/L) (USEPA, 2015c). 

Based on the results of the UCMR 2 

samples, the estimated population 

exposed to terbufos sulfone at a level of 

public health concern (based on the 

HRL for terbufos) is 44,600 (0.02% of 

the population served by PWSs). 

Finished water data for terbufos and 

terbufos sulfone from California, Iowa, 

USDA and USGS are consistent with the 

UCMR 1 and UCMR 2 data. Terbufos 

and (very limited) terbufos sulfone 

occurrence data for ambient water from 

the EPA, STORET and several USGS 

programs or studies are also consistent 

with those for finished water. These 

data sources are discussed in the 

October 2014 Federal Register notice of 

the Preliminary Regulatory 

Determination 3 (USEPA, 2014c). 

D. Public Comments on Four 

Contaminants With Final Regulatory 

Determinations 

The agency received comments in 

support of the agency’s preliminary 

determinations not to regulate 

dimethoate, 1,3-dinitrobenzene, terbufos 

and terbufos sulfone. The agency did 

not receive any comments to the 

contrary. 

Agency Response: EPA agrees with 

the comments and, as previously 

explained, is making final 

determinations not to regulate 

dimethoate, 1,3-dinitrobenzene, terbufos 

and terbufos sulfone. 

V. Summary of Public Comments on 

Strontium and the Agency’s Responses 

A. Background on Strontium and the 

EPA’s Preliminary Determination 

Strontium is a naturally occurring 

element (atomic number 38) and a 

member of the alkaline earth metals 

(ANL, 2007). There are several 

radioactive strontium isotopes formed 

by nuclear fission of uranium or 

plutonium. Since drinking water 

contamination by radioactive isotopes, 

including beta particle emitters, is 

covered under the existing 

Radionuclides Rule, this section 

describes the stable 88Sr isotope. 

In October 2014, the agency made a 

preliminary determination to regulate 

strontium with an NPDWR after 

evaluating the available health, 

occurrence and other related 

information against the three SDWA 

statutory criteria. Specifically, EPA 

made a preliminary determination that 

(a) strontium may have an adverse effect 

on the health of persons, (b) it is known 

to occur or there is substantial 

likelihood that strontium will occur in 

public water systems with a frequency 

and at levels of public health concern 

and (c) regulation of strontium with an 

NPDWR presents a meaningful 

opportunity to reduce health risks for 

persons served by PWSs. EPA describes 

the underlying science in support of 

these criteria in the Federal Register 

notice of the Preliminary Regulatory 

Determination 3 (USEPA, 2014c). 

In the Federal Register notice of the 

Preliminary Regulatory Determination 3, 

EPA calculated a non-cancer HRL of 

1500 mg/L for strontium using the 

reference dose of 0.3 mg/kg/day, a 

default Relative Source Contribution 

(RSC) of 20% and age-specific exposure 

factors (i.e., drinking water intake 

expressed as liters per kg of body 

weight) for the sensitive population of 

birth through 18 years to reflect the 

most active period of bone growth and 

development. The RSC is the level of 

exposure believed to result from 

drinking water when compared to other 

sources (e.g., food, ambient air). In the 

Preliminary Regulatory Determination 3 

EPA used the default 20% RSC to 

calculate the HRL. For more detailed 

information see the October 20, 2014, 

Federal Register notice of the 


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18 Federal Register / Vol. 81, No. 1 / Monday, January 4, 2016 / Rules and Regulations 

Preliminary Regulatory Determination 3 

(USEPA, 2014c). 

After consideration of public 

comments on the preliminary regulatory 

determination for strontium (see Section 

V.B.), the agency is delaying the final 

determination for strontium in order to 

consider additional scientific data and 

decide whether there is a meaningful 

opportunity for health risk reduction by 

regulating strontium in drinking water. 

B. What comments did the EPA receive 

on strontium? 

Some commenters supported the 

preliminary determination to regulate 

strontium. These commenters supported 

a regulation due to the adverse effect on 

bone growth and/or the potential for 

elevated levels of strontium in the 

environment as a result of spills and 

disposal of waste products related to gas 

production. 

Many comments called upon the 

agency to delay the final determination, 

collect more data and perform 

additional analyses before making a 

final determination for strontium. 

Specifically, the comments were 

focused on the following areas: The 

relationship between occurrence and 

health risk, the RSC of strontium, the 

costs and benefits of a potential 

strontium regulation and the feasibility 

of treating strontium. 

Three commenters questioned 

whether enough water systems show 

strontium at levels and frequency of 

concern that a meaningful reduction in 

health risk can be achieved through a 

national regulation. Two of these 

commenters suggested conducting an 

epidemiology study that evaluates 

whether adverse human health effects 

are occurring and at what drinking 

water concentrations (and frequency of 

occurrence) to determine whether there 

is a meaningful opportunity for health 

risk reduction of a regulation. 

Two commenters indicated the 

agency should quantify the RSC or 

provide stronger justification for using 

an RSC of 20%. One commenter stated 

the RSC has a significant impact on the 

reference dose. One commenter stated 

that defaults of 20% and 80% have 

utility in relatively simple 

circumstances where it is accepted that 

the drinking water component is either 

very small or large. The commenter 

indicated that it is essential to analyze 

and quantify the RSC when it is 

intermediate and there are data to 

perform a meaningful estimate. The 

commenter asserted that it is essential 

because the impact on the MCLG and 

ultimately the MCL and compliance 

costs can become significant. 

Several commenters indicated 

concerns with the costs and benefits of 

a potential strontium regulation. One 

commenter urged the agency to update 

the current affordability standard under 

SDWA before promulgating any new 

NPDWRs in order to allow rural and 

small communities to utilize the most 

economical and safe treatment options. 

One commenter stated that the agency 

failed to estimate the social benefits and 

social costs in its analysis for the 

strontium determination, specifically 

the additional energy usage and its 

externalities. Several commenters 

compared the cost of a potential 

strontium regulation to that of the 

arsenic regulation, based on the 

percentage and type of systems with 

strontium occurrence at levels of 

concern. 

Several commenters supported the 

agency’s commitment to conducting 

more extensive treatment research prior 

to promulgating a regulation for 

strontium. Two commenters indicated 

that the treatment technology to remove 

strontium may remove beneficial 

alkaline earth metals, such as calcium, 

that partially counter the uptake of 

strontium. 

Agency Response: The agency is 

delaying the final determination for 

strontium in order to consider 

additional scientific data and decide 

whether there is a meaningful 

opportunity for health risk reduction by 

regulating strontium in drinking water. 

Strontium is known to occur in food, 

ambient air and soil. While data on 

levels in those media and estimates of 

intake from those sources were limited 

when EPA made the preliminary 

determination to regulate strontium, the 

EPA is evaluating recent additions to 

the exposure database to determine if 

the agency can develop a data-derived 

RSC rather than using a default 20% 

RSC in the calculation of the HRL. In 

the absence of this type of relevant 

exposure information, the agency 

supports the use of the default RSC and 

may ultimately use the default 20% RSC 

in the final regulatory determination for 

strontium and for other compounds in 

the future. The agency selects the 

default RSCs for regulatory 

determinations based on the 

Methodology for Deriving Ambient 

Water Quality Criteria for the Protection 

of Human Health (USEPA, 2000). 

If the agency makes a final 

determination to regulate strontium, the 

EPA will conduct tests on treatment 

technologies for strontium prior to 

developing a regulation. The agency 

understands that strontium may cooccur with beneficial calcium in some 

drinking water systems and treatment 

technologies that remove strontium may 

also remove calcium. The agency is 

evaluating the effectiveness of treatment 

technologies under different water 

conditions, including calcium 

concentrations. The agency will 

continue to work with stakeholders in 

evaluating treatment technologies for 

strontium. 

At this time, the agency does not plan 

to initiate any longer term health effect 

studies, including human 

epidemiological studies on the 

relationship of skeletal effects and 

strontium exposure levels through 

consumption of drinking water and 

foods. The agency will continue to 

evaluate new health studies related to 

strontium exposure, including any 

epidemiology studies. It should be 

noted that while the agency is not 

precluded from conducting 

epidemiological studies, the agency is 

not required to do so to support the 

decision to regulate a contaminant. 

An evaluation of the costs and 

benefits of a potential strontium 

regulation is outside the scope of the 

regulatory determination process. If the 

agency decides to regulate strontium, as 

part of the regulation development 

process, the agency will conduct a 

health risk reduction and cost analysis, 

including an evaluation of the costs and 

benefits of regulating strontium. 

VI. Next Steps 

Prior to making a final regulatory 

determination for strontium, the agency 

will consider additional data gathered 

and analyses completed after 

publication of the preliminary 

determination (for further information, 

see discussion in section V.B. of this 

notice). The agency published the Draft 

Contaminant Candidate List 4 (CCL 4) 

on February 4, 2015 (USEPA, 2015a) 

and will issue a Final CCL 4 after 

consideration of public comments 

received. The agency will evaluate and 

consider contaminants on the Final CCL 

4 for the Fourth Regulatory 

Determination. 

VII. References 

Argonne National Laboratory (ANL). 2007. 

Radiological and Chemical Fact Sheets to 

Support Health Risk Analyses for 

Contaminated Areas. Environmental 

Science Division. Available on the 

Internet at: http://

www.gfxtechnology.com/

ArgonneRadFacts.pdf. 

HSDB. 2010. Available on the Internet at: 

http://toxnet.nlm.nih.gov/cgi-bin/sis/

htmlgen?HSDB. Accessed September 

2010. 

USEPA. 2000. Methodology for Deriving 

Ambient Water Quality Criteria for the 


tkelley on DSK3SPTVN1PROD with RULES
Federal Register / Vol. 81, No. 1 / Monday, January 4, 2016 / Rules and Regulations 19 

Protection of Human Health (2000). EPA 

822–B–00–004. 

USEPA. 2006. Reregistration Eligibility 

Decision for Terbufos. Office of Pesticide 

Programs. Available on the Internet at: 

http://archive.epa.gov/pesticides/

reregistration/web/pdf/terbufos_red.pdf. 

Accessed Oct 2015. 

USEPA. 2007. Revised Interim Reregistration 

Decision for Dimethoate. Available on 

the Internet at: http://archive.epa.gov/

pesticides/reregistration/web/pdf/

dimethoate_ired_revised.pdf. Accessed 

October 2015. 

USEPA. 2008. The Analysis of Occurrence 

Data from the First Unregulated 

Contaminant Monitoring Regulation 

(UCMR 1) in Support of Regulatory 

Determinations for the Second Drinking 

Water Contaminant Candidate List. EPA 

815–R–08–012. June 2008. 

USEPA. 2009. Drinking Water Contaminant 

Candidate List 3—Final. Federal 

Register. Vol. 74, No. 194, p. 51850. 

October 8, 2009. 

USEPA. 2012. Storage and Retrieval 

(STORET) Data Warehouse. Available on 

the Internet at: http://www.epa.gov/

storet/index.html. Data Warehouse. 

Accessed March 2012. 

USEPA. 2014a. Protocol for the Regulatory 

Determinations 3. Including Appendices 

A–F. EPA 815–R14–005. April 2014. 

USEPA. 2014b. Regulatory Determinations 3 

Support Document. EPA 815–R14–003. 

April 2014. 

USEPA. 2014c. Announcement of the 

Preliminary Regulatory Determinations 

for Contaminants on the Third Drinking 

Water Contaminant Candidate List; 

Proposed Rule. Federal Register. Vol. 79, 

No. 202, p. 62716. October 20, 2014. 

USEPA. 2015a. Drinking Water Contaminant 

Candidate List 4—Draft. Federal 

Register. Vol. 80, No. 23, p. 6076. 

February 4, 2015. 

USEPA. 2015b. Regulatory Determinations 3 

Support Document (Final). EPA 815– 

R15–014. December 2015. 

USEPA. 2015c. Occurrence Data from the 

Second Unregulated Contaminant 

Monitoring Regulation (UCMR 2). EPA 

815–R15–013. December 2015. 

Dated: December 22, 2015. 

Gina McCarthy, 

Administrator. 

[FR Doc. 2015–32760 Filed 12–31–15; 8:45 am] 

BILLING CODE 6560–50–P 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

50 CFR Part 635 

[Docket Nos. 120328229–4949–02 and 

150121066–5717–02] 

RIN 0648–XE346 

Atlantic Highly Migratory Species; 

Atlantic Bluefin Tuna Fisheries 

AGENCY: National Marine Fisheries 

Service (NMFS), National Oceanic and 

Atmospheric Administration (NOAA), 

Commerce. 

ACTION: Temporary rule; annual 

adjustment of Atlantic bluefin tuna 

Purse Seine and Reserve category 

quotas; inseason quota transfer from the 

Reserve category to the Longline 

category. 

SUMMARY: NMFS is adjusting the 

Atlantic bluefin tuna (BFT) Purse Seine 

and Reserve category quotas for 2016, 

based on regulations implementing 

Amendment 7 to the 2006 Consolidated 

Highly Migratory Species Fishery 

Management Plan. NMFS also is 

transferring inseason 34 metric tons (mt) 

of BFT quota from the Reserve category 

to the Longline category. This action is 

based on consideration of the regulatory 

determination criteria regarding 

inseason adjustments. The transfer to 

the Longline category is applied to 

eligible Atlantic Tunas Longline 

category permitted vessels with 

Individual Bluefin Quota (IBQ) shares, 

and as a result of this transfer, current 

IBQ vessel accounts will be distributed 

0.25 mt of IBQ allocation each. 

DATES: Effective January 1, 2016, 

through December 31, 2016. 

FOR FURTHER INFORMATION CONTACT: 

Sarah McLaughlin, Tom Warren, or 

Brad McHale, 978–281–9260. 

SUPPLEMENTARY INFORMATION: 

Regulations implemented under the 

authority of the Atlantic Tunas 

Convention Act (ATCA; 16 U.S.C. 971 et 

seq.) and the Magnuson-Stevens Fishery 

Conservation and Management Act 

(Magnuson-Stevens Act; 16 U.S.C. 1801 

et seq.) governing the harvest of BFT by 

persons and vessels subject to U.S. 

jurisdiction are found at 50 CFR part 

635. Section 635.27 subdivides the U.S. 

BFT quota recommended by the 

International Commission for the 

Conservation of Atlantic Tunas (ICCAT) 

among the various domestic fishing 

categories, per the allocations 

established in the 2006 Consolidated 

Highly Migratory Species Fishery 

Management Plan (2006 Consolidated 

HMS FMP) (71 FR 58058, October 2, 

2006), as amended by Amendment 7 to 

the 2006 Consolidated HMS FMP 

(Amendment 7) (79 FR 71510, December 

2, 2014). NMFS is required under ATCA 

and the Magnuson-Stevens Act to 

provide U.S. fishing vessels with a 

reasonable opportunity to harvest the 

ICCAT-recommended quota. 

Annual Adjustment of the BFT Purse 

Seine and Reserve Category Quotas 

In 2015, NMFS implemented a final 

rule that increased the U.S. BFT quota 

and subquotas per ICCAT 

Recommendation 14–05 (80 FR 52198, 

August 28, 2015). As a result, based on 

the currently codified U.S. quota of 

1,058.79 mt (not including the 25 mt 

allocated by ICCAT to the United States 

to account for bycatch of BFT in pelagic 

longline fisheries in the Northeast 

Distant Gear Restricted Area), the 

baseline Purse Seine, Longline, and 

Reserve category quotas are codified as 

184.3 mt, 148.3 mt, and 24.8 mt, 

respectively. See § 635.27(a). 

Pursuant to § 635.27(a)(4), NMFS has 

determined the amount of quota 

available to individual Atlantic Tunas 

Purse Seine category participants in 

2016, based on their BFT catch 

(landings and dead discards) in 2015. 

Specifically, NMFS is making available 

to each Purse Seine category participant 

100 percent, 75 percent, 50 percent, or 

25 percent of the individual baseline 

quota allocations based on 2015 catch, 

as described in § 635.27(a)(4)(ii), and is 

reallocating the remainder to the 

Reserve category for 2016. NMFS has 

calculated the amounts of quota 

available to individual Purse Seine 

fishery participants based on their 

individual catch levels in 2015 and the 

codified process adopted in 

Amendment 7. Total Purse Seine 

category BFT catches were 38.8 mt (33.9 

mt of landings and 4.9 mt of dead 

discards) in 2015. Consistent with 

§ 635.27(a)(4)(v)(C), NMFS will notify 

Atlantic Tunas Purse Seine fishery 

participants of the amount of quota 

available for their use this year through 

the Individual Bluefin Quota electronic 

system established under § 635.15 and 

in writing. 

Based on the procedures described 

above and by summing the individual 

available allocations, NMFS has 

determined the 2016 Purse Seine 

category quota available to Purse Seine 

fishery participants is 82.9 mt. Thus, the 

amount of Purse Seine category quota to 

be reallocated to the Reserve category is 

101.4 mt. This reallocation would result 

in a 2016 Reserve category quota of 

126.2 mt (24.8 mt + 101.4 mt). However, 

NMFS also is taking action, as described 


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