-- 

Wednesday

July 8, 1987 

Part II 

Enwironmental 

Protection Agency 

40 CFR Parts 141 and 142 

National Primary Drinking Water 

Regulations-Synthetic Organic 

Chemicals; Monitoring for Unregulated 

Contaminants; Final Rule 
25690 Federal Register I Vol. 52, No. 130 1 Wednesday, July 8, 1987 ] Rules and Regulations 

ENVIRONMENTALPROTECTION 

AGENCY 

40 CFR Parts 141 and 142 

[WH-FRL-3213-81 

National Primary Drinking Water 

Regulations;Synthetic Organic 

Chemicals; Monitoringfor Unregulated 

Contaminants 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final Rule. 

SUMMARY:In this notice, EPA is 

promulgating National Primary Drinking

Water Regulations (NPDWRs)for 

certain volatile synthetic organic . 

chemicals (VOCs). Specifically, this 

notice promulgates maximum 

contaminant levels (MCLs) for: 

Trichloroethylene, carbon tetrachloride,

1.1,l-trichloroethane. vinyl chloride, 12­

dichloroethane, benzene, 1,ldichloroethylene, and paradichlorobenzene. The NPDWRs also 

include monitoring, reporting and public

notification requirements for these eight

VOCs. EPA is also publishing the 

maximum contaminant level goal

(MCLG)for para-dichlorobenzene. This 

notice specifies the best available 

technology (BAT) upon which the MCLs 

are based and BAT for the purpose of 

issuing variances. In this notice, the 

Agency is also promulgating procedures

by which systems may obtain variances 

and exemptions from these NPDWRs. In 

addition to the NPDWRsfor the eight

VOCs, the Agency is also promulgating

monitoring requirements for 51 other 

synthetic organic chemicals which are 

not regulated by NPDWRs. 

EPA proposed NPDWRs, including

MCLs, for the eight VOCS listed above 

on November 13.1985 (50 FR 46902).

New data on the toxicology of paradichlorobenzene became available after 

the November 13 notice which changed

its health effects classification. EPA 

proposed to amend the MCLG and 

reproposed the MCL for this 

contaminant on April 17,1987(52FR 

12876).based on this new information. 

EFFECTIVE DATES This regulation is 

effective January 9,1989,except for 

0 g 141.24(g),141.35,and 141.40.The 

information collection requirements in 

40CFR 141.24(g),141.35,and 141.40 are 

effective January 1,1988,if the 

information collection request is clear 

by the Office of Management and 

Budget (OMB) and an OMB clearance 

number is assigned prior to that date. If 

not, the requirements will be effective 

when OMB clears the request and a 

notice is published. In accordance with 

40CFR 23.7. this regulation shall be 

considered final agency action for the 

purposes of judicial review at 1f10pm 

eastern daylight savings time on July22 

1987. 

ADDRESSES: Public comments on the 

proposal, major supporting documents. 

and a copy of the index to the public

docket for this rulemaking are available 

for review during normal business hours 

at the EPA, Room 2904(rear) in the 

Public Information Reference Unit401 

M Street, SW., Washington, DC 20460. A 

complete copy of the public docket is 

available for inspection at EPA m 

Washington, DC by appointment by

contacting Ms.Colleen Campbell 202/ 

382-3027. 

FOR FURTHER INFORMATION CONTACT: 

Joseph A. Cotruvo, Ph.D., Director. 

Criteria and Standards Division. Office 

of Drinking Water (WH-550),US. 

Environmental Protection Agency. 4M M 

Street, SW., Washington, DC20460,202/ 

382-7575,or one of the EPA Regional

Office contacts listed in "Supplementry

Information". Information may also be 

obtained from the EPA Drinking Water 

Hotline. The toll-free number is 800/426­

4791 and the Washington, DC number is 

382-5533. 

SUPPLEMEWARY INFORMATION: 

EPA Regional Offices 

I. JFKFederal Bldg., Room 2203,Boston, 

MA 02203,Phone: (617)565-3610, 

Jerome Healey

II. 26 Federal Plaza, Room 824,New 

York, NY 10278,Phone: (n2)Z64-1800, 

Walter Andrews 

In. 841Chestnut Street, Philadelphia, PA 

19107,Phone: (215)597-9873,Jon 

Capacasa

IV.345Courtland Street, Atlanta, GA 

30365,Phone: (404)347-2913,William 

Patton 

V.230S.Dearborn Street, Chicago,IL 

60604,Phone: (312)353-2650,Joseph

Harrison 

VI.1445Ross Avenue, Dallas, TX 75202, 

Phone: (214)655-7155,Thomas Love 

VII. 726Minnesota Ave., Kansas City,

KS 66101,Phone: (913)236-2815, 

Gerald R.Foree 

VIII. One Denver Place, 999 18th Street, 

Suite 300,Denver, CO 80202-2413, 

Phone: (303)293-1424,Marc Alston 

E.215Fremont Street, San Francisco, 

CA 94105,Phone: (415)974-0763, 

William Thurston 

X.1200Sixth Avenue, Seattle, WA 

98101,Phone: (206) 4424092,Richard 

Thiel 

Abbreviations Used in This Notice 

BAT Best Available Technology

BTGA: Best Technology Generally

Available 

CWS: Community Water System i 

EMSL: EPA Environmental Monitod 

and Support Laboratory (Cincinne 

GAC: Granular Activated Carbon 5 

LOQ:Limit of Quantitation 

MCL Maximum Contaminant Level 

(expressed as rng/l)*

MCLG Maximum Contaminant hvi 

Goal 

h4DL Method Detection Limit 

mgd: Million Gallons per Day 

NIPDWR: National Interim Primary 

Drinking Water Regulation

NPDWR: National Primary Drinking 

Water Regulation

NTNCWS: Non-transient Non- , community Water System 

pdcb: para-Dichlorobenzene 

WE: Point-of-Entry Technologies

POU. Point-of-Use Technologies 

PQL Practical Quantitation Level 

PTA: Packed Tower Aeration 

PWS: Public Water System 

PWSS: Public Water System Supem 

RMCL Recommended Maximum 

Contaminant Level 

SDWA: Safe Drinking Water Act, or 

"Act." as amended in 1986 

THMs:Trihalomethanes 

URW.Unreasonable Risk to Health 

VOC: Volatile Synthetic Organic 

Chemical 

'1.0~micrograms (ug)= 1 milligram ( 

Table of Contents 

I. Summary of Today's Actions 

11. Background 

A. Statutory Authority

B. RegulatoryBackground

C. Public Comments on the Proposal

III. Explanation of Today's Actions 

A. Non-transient Non-communitv Watt 

System

B. MCLG for Dara-dichlorobenzene 

C. MCLSfor VOCS 

1. Treatment Technologies 

2. costs 

3. Other Factors 

4. Summary of MCL Determinations 

D. Other TreatmentTechnologies

E Analytical Methods and Compliancc

Monitoring Requirements 

1.Analytical methods 

2 Compliance Monitoring Requireme]

F. Laboratory Approval

G. Variances and Exemptions 

1. Variances 

2. Exemptions 

3. Central Treatment vs. POU/Bottled

Water 

H. Public Notification 

1. Reporting Requirements 

J. Total Volatile Synthetic Organic

Chemicals (TVOC)

K. Monitoring for Unregulated

Contaminants 

IV.Effective Dates 

V. Impact Analyses 

VI. References and Public Docket 
3 $

$-. Federal Register f Vol.

* 

vstem 

Monito% 

Cincinnati 

:arbon 

for

,nt Level tMe 

iant Level 

Requirements 

lit P 4-Analyses within the Acceotancc! 

1Y 

Primary hornDrinking Water Using Pack2 

n rower Aeration or GranularActivated 

Drinking 

on1 

e mary of Today's Action 

logies Kcability jgies 

Level ,e requirements of this notice apply 

n Icommunitywater systems (CWS)

ion-transient non-community water 

1 Supervisio !ms (NTNCWS).

In-transient non-community water mum !fernsare those which regularly serve 

ksame 25 or more persons at least 6 r Act, or th pthsper year. 5 id MCLG: x 

oHealth ; a-dichIorobenzene-o.W5 mg/l 

:anic ;I MCLs: 

1enzene-0.005mg/l illigram [ql' rarbon tetrachloride4.m mg/l

,2-dichloroethane-0.005 mn/l 

oposal

Jns 

nity Water Section 1412 of the SD WA 

izene acked tower aeration (PTA)or 

@nular activated carbon (GAC) for all 

dated VOCs, except vinyl chloride. 

'�A for vinyl chloride. 

tQther effective removal technologies 

:ies kat treat all of the drinking water in a 

rnpliance 

1.mpliance. 

PT under Section 1415 (Variances): 

me technologies are BAT as those 

bder Section 1412. 

/Bottled 

De basic monitoring requirements 

anic @ as follows: 

Quarterly samples for each ground

nd surface water source. 

Fomposite samples of up to five 

!Wces are allowed. 

t 

I 

Determination of compliance is 

established as follows: Both ground and 

surface water systems must calculate a 

running average of the concentration of 

each VOC, over one year, taking at least 

one sample per quarter, for each source. 

All samples must be used. 

For ground waters, the State as 

primacy agent may reduce the sampling

frequency if regulated VOCs are not 

detected in the first sample. The 

minimum possible monitoring

requirement for compliance is one 

sample per source. 

Repeat monitoring varies from 

quarterly to once per five years. States 

determine repeat monitoring

requirements based on: (1)Whether or 

not VOCs have been detected in the 

initial sampling, and (2) the vulnerability

of the system to contamination 

(determined by the State). 

Analytical Methods. 

1.EPA Method 502.1-Volatile 

Halogenated Organic Compounds in 

Water by F'urge and Trap Gas 

Chromatography. 

2. EPA Method 502.2-Volatile 

Organic Compounds in Water by Purge

and Trap Gas Chromatography with 

Photoionization and Electrolytic

Conductors in Series. 

3. EPA Method 503.1-Volatile 

Aromatic and Unsaturated Organic

Compounds in Water by Purge and Trap

Gas Chromatography.

4. EPA Method 504-12-

Dibromoethane and 1,2-Dibromo-3­

chloropropane in Water by

Microextraction and Gas 

Chromatography.

5. EPA Method 524.1-Volatile 

Organic Compounds in Water by Purge

and Trap Gas Chromatography/Mass

Spectrometry. 

6.EPA Method 524.2-Volatile 

Organic Compounds in Water by Purge

and Trap Capillary Column Gas 

Chromatography/Mass Spectrometry. 

Labomtory Certification Criteria 

Vinyl Chloride: 

k 40 percent at any concentration 

All others: 

It20 percent > 0.010 mg/l

i- 40 percent 5 0.010 mg/l 

Point-ofEntry Devices [POEj, Point-ofUse Devices {POUj,and Bottled Water 

POE may be used to achieve 

compliance with MCk, however, POE is 

not BAT. 

17 / Rules and Regulations 25691 

POU and bottled water cannot be 

used to achieve compliance with the 

MCLs, however, either may, at State 

discretion, be a condition of granting a 

variance or exemption. 

Variances and Exemptions 

Prior to issuing a variance or 

exemption, the State has the authority to 

require the public water system to 

implement additional interim control 

measures if an unreasonable risk to 

health exists: among other mitigation

techniques, States may require

installation of point-of-use devices or 

distribution of bottled wafer to each 

customer as measures to reduce the 

health risk before granting a variance or 

exemption. 

Monitoringfor Unregulated

Conturninants 

One sample per source is required 

every five years. 

Systems sample according to the 

procedures and schedules established 

for VOC compIiance monitoring. 

Monitoring for the 50 unregulated

contaminants is as specified below: 

List 1:monitoring required for all 

systems (34contaminants). 

List 2: monitoring required for 

vulnerable systems (2 contaminants). 

List 3: monitoring required at State 

discretion f15contaminants). 

Repeat monitoring frequency: Every

five years. 

EPA will specify a new list before 

repeat monitoring is required (within

five years). 

11. Background 

A. Statutory Authority 

Section 1412of the Safe Drinking

Water Act. as amended in 1986 

("SDWA' or "the Act"), requires EPA to 

publish Maximum Contaminant Level 

Goals (MCLGs) and promulgate

National Primary Drinking Water 

Regulations (NPDWRs) for 

contaminants in drinking water which 

may cause any adverse effect on the 

health of persons and which are known 

or anticipated to occur in public water 

systems. Under Section 1401. the 

NPDWRs are to include Maximum 

Contaminant Levels (MCLs) and 

"criteria and procedures to assure a 

supply of drinking water which 

dependably complies" with such MCh. 

Under Section 1412(b)(7)(A),if it is not 

economically or technically feasible to 

ascertain the ievel of a contaminant in 

drinking water. EPA may require the use 

of a treatment technique instead of an 

MCL 
1.MCLs. MCLGs, and BAT 

EPA is to establish MCLGs at the 

level at which no known or anticipated

adverse effects on the health of persons 

occur and which allow an adequate

margin of safety. MCLGs are 

nonenforceable health goals. EPA 

published MCLGs. previously called 

Recommended Maximum Contaminant 

Levels (RMCLs). for trichloroethylene,

carbon tetrachloride, 1.1,1­

trichloroethane. vinyl chloride, 12­

dichloroethane, benzene, 1,ldichloroethylene, and paradichlorobenzene on November 13,1985. 

The Agency reproposed the MCLG for pDCB on April 17,1987(52 F’R 12876),

based on new health assessment data. 

MCLs are enforceable standards 

which the Act directs EPA to set as 

close to the MCLGs as feasible. 

“Feasible” means feasible with the use 

of the best technology, treatment 

techniques, or other means which the 

Administrator finds available (taking 

cost into consideration) after 

examination for efficacy under field 

conditions and not solely under 

laboratory conditions. Also,the SDWA 

requires the Agency to identify the best 

available technology (BAT) which is 

feasible for meeting the MCL for each 

contaminant. NPDWRsare to be 

amended whenever changes ~ 

technology or other means permit 

greater protection of the health of . 

persons, and the regulations are to be 

reviewed no less frequently than every

three years. 

2. Variances and Exemptions 

Section 1415authorizes the State (the 

term “State” is used in this Preamble to 

mean the State agency with primary

enforcement responsibility for the public 

water supply system program, or 

“primacy,” or EPA if the State does not 

have primacy] to issue variances from 

NPDWRs. The State may issue a 

variance if it determines that a system 

cannot comply with an MCL despite

application of the best available . technology (BAT). Under Section 1415, 

EPA must propose and promulgate its 

finding of the best technology, treatment 

techniques, or other means available for 

each contaminant (BAT), for purposes of 

Section 1415variances. at the same time 

that it proposes and promulgates a 

maximum contaminant level for each 

such contaminant. EPA’s finding of best 

technology, treatment techniques, or 

other means available for purposes of 

issuing variances may vary among 

systems, depending upon the number of 

persons served by the system or for 

other physical conditions related to 

engineering feasibility and costs of 

complying with MCLs, as considered 

appropriate by EPA. The State may not 

issue a variance where an unreasonable 

risk to health exists. When a State 

grants a variance, it must at the same 

time prescribe a schedule for (1)

compliance with the NPDWR and (2)

implementation of such additional 

control measures as the State may

require.

Under section 1416(a),the State may 

exempt a public water system from any

MCL or treatment technique

requirement if it finds that (1)due to 

compellingfactors (which may include 

economic factors), the system is unable . to comply, (2) the system was in 

operation on the effective date of the 

MCL or treatment technique, or, for a 

newer system, that no reasonable 

alternative source of drinking water is 

available to that system, and (3)the 

exemption will not result in an 

unreasonable risk to health. Under 

section 1416(b),at the same time it 

grants an exemption, the State is to 

prescribe a compliance schedule and a 

schedule for implementation of any

required interim control measures. For 

exemptions from a NPDWR promulgated

after enactment of the SDWA 

amendments, such as the NPDWRs for 

the VOCs promulgated in this notice, the 

compliance date must be no later than 

12 months after the date of issuance of 

the exemption. However, the State may

extend the final compliance date for a 

period not to exceed three years after 

the date of issuance of the exemption if 

the public water system establishes that 

it is taking all reasonable steps to meet 

the standard once: (11the system cannot 

meet the standard without capital

improvements which cannot be 

completed within the period of such . exemptions: (2) in the case of a system

which needs financial assistance for the 

necessary improvements,the system has 

entered into an agreement to obtain 

such financial assistance; or (3) the 

system has entered into an enforceable 

agreement to become part of a regional

public water system. For systems that 

serve 500 or fewer service connections 

and which need financial assistance to 

come into compliance, the State may 

renew the exemption for additional twoyear periods if the system is taking all 

practicable steps to meet the 

requirements in the previous sentence. 

3. Primacy. 

Today’s regulation is one of many

which EPA will promulgate during the 

next few years, as required by the 1986 

Amendments. To retain primary

enforcement responsibility (‘primacy”)

for the public water system supervision 

program, States must revise their 

Water System Supervisio 

program, including the changes

contained in any new regulations.

the effective date onward. 
52, No. 130 / Wednesday, July 8. 1987 / Rules and Regulations 

tion EPA plans to specify, as 

revisions to 40CFR Part 142, 

nts contained in this ,must comply with Federal 

requirements. Failure by a State with 

primacy to establish its own 

requirements does not exempt a system

from the Federal requirements and 

systems which violate a Federal 

requirement contained in this regulation

will be subject to Federal enforcement. 

Public water systems located in States 

with primacy should, however, reporf

analytical results and all other 

infomation required by this regulation 

to the State even if the State has not yet

adopted the requirementsof the 

regulation. It will be the responsibility of 

the State, in such cases. to forward 

information to EPA. 

4. Monitoring, Quality Control, and 

Records 

Under section 1401(1)(D)of the Act, 

NPDWRs are to contain “criteria and 

procedures to assure a supply of 

drinking water which dependably

complies with such maximum 

contaminant levels; including quality

control and testing procedures to insure 

compliance with such levels . . ..”In 

addition, Section 1445states that, “every 

person who is a supplier of water. .. shall establish and maintain such 

records, make such reports, conduct 

such monitoring and provide such 

information as the Administratormay

reasonably require by regulation to 

assist him in establishing regulations, . . .in evaluating the health risks of 

unregulated contaminants or in advising

the public of such risks.” Section1445 

also requires EPA to promulgate

regulations requiring every public water 

system to conduct a monitoring program

for unregulated contaminants. 

5. Non-transient Non-community Water 

Systems 

Public water systems are defined in 

the Act at section 1401[l)(D)(4)as those 

systems which provide piped water for 

human consumption and have at least 15 

connections or regulady serve at least 

25 people. The category “public water 

system” is composed of community and 

non-community water systems.The 

community water system is one which 

serves at least 15 connectionsused by

year-round residents or regularly serves 

at least 25 year-round residents (40CFR 

1412). Non-community systems, by

definition, are all other water systems.

Non-community systems include 

transient systems leg.. campgrounds, 

gas stations) and non-transient systems

(e.g., schooL, workplaces, hospitals

which have their own water supply and 

serve the same population Over six 

months of a year), as explained in more 

detail later. 

6. Public Notification 

Section 1414(c)of the Act requires the 

owner or operator of a public water 

system which fails to comply with an 

applicabie maximum contaminant level 

or treatment technique requirement,

testing procedure. or section 1445(a)

monitoring requirement to give notice to 

the persons served by the water system.

Owners and operators of public water 

systems for which variances or 

exemptionsare in effect, or which fail to 

comply with the requirement of any

schedule imposed pursuant to a 

variance or exemption, must also give

notice. Section 1445(a)(5)also requires

public water systems to notify the 

persons served by the water system and 

the Administratorof EPA of the 

availability of the results of monitoring

for unregulated contaminants. 

B. Regulatory Background 

On June12,1984 (49 FFt 243301,EPA 

proposed MCLGs for the eight VOCs 

covered in today’s notice: Benzene,

carbontetrachloride, 1,2dichloroethane. ­

trichloroethylene, kldichloruethylene,

l,l,l-trichloroethane, paradichlorobenzene, and vinyl chloride. On 

November 13,1985,EPA published the 

final MCLGs and proposed MCLs for 

these eight VOCs I50 FR 46880 and 50 

FR 46902). Detailed discussions of the 

history of the regulation of VOCs in 

drinking water together with 

information on occurrencein drinking 

water and any adverse effects of human 

exposure were presented in these 

notices. This background is summarized 

below. EPA proposed to amend the 

MCLG for para-dichlorabenzene(pDCB)and reproposed the MCL for p

DCB on April 17,1987 (52FR 12876). 

1.MCLGs, MCLs, and Monitoring 

In the November 13,1985,notice for 

substances consideredto be knownor 

probable human carcinogens, EPA set 

the MCLGs at zem. For substances it did 

not consider known or probable human 

carcinogens, EPA set the MCLGs based 

upon chronic toxicity data. Table 1 

summarizes the final MUS for these 

VOCs. The ChemicalManufacturers 

Association, the Halogenated Solvents 

Industry Alliance,and the Natural 

Resources Defense Council each filed 

petitions for reviewof one or more of 

these MCLGs. These petitions are 

pending before the US.Court of 

Appeals for the District of Columbia 

Circuit 

The establishment of an MCLG at 

zem does not imply that actual harm 

would necessarily occurto humans at a 

level somewhat above zero. but rather 

that zero is an aspirational goal, which 
includes a margin of safety, within the day but throughout much of the year, comments received and the 

context of the Safe Drinking Water Act. and often for many years. responses are presented in the . 

MCLs, even though set at levels above At the same time that EPA proposed document "Summary of Corne 

aspirational MCLGs,based otl the MCLs, it also proposed minimum EPA responses on the Proposed 

feasibility considerations, are also compliance monitoring requirements 

considered safe levels that are consisting of one initial round of 

protective of public health. monitoring to determine the extent of 

EPA proposed the MCLs for the eight contamination and certain follow-up 

VOCs based upon an evaluation of (1) monitoring requirements if the initial 

the availability and performance of round of monitoring indicated VOC 

treatment technologies [Best Technology contamination. The November 1985 

Generally Available (BTGA), under notice also proposed monitoring 

Sections 1412and 1415,was identified requirements for 51 additional 

as FTA or GAC], (2)the availability, unregulated contaminants [all VOCs) 

performance, and cost of analytical under Section 1445.These requirements 

methods, and (3)an assessment of the were very similar to the compliance 

costs of application of various monitoring requirements proposed for 

technologies to remove VOCs from the eight MCLs. The major difference 

drinking water to various. was that for the unregulated 

concentrations. Table 1 summarizes the contaminants only one round of 

final MCLGs and the proposed and final monitoring was proposed (the 

MCLs that EPA is promulgating in this compliance monitoring requirements 

rule. called for repeat samplingranging in 

frequency from quarterly to every 5 

TABLEFI FINAL MCLGS AND PFiOPoSED AND years, depending on the prior monitoring 

FINAL MCLS FOR THE v%S results and a determination of a

system's vulnerability to 

cwnpwnd 

Final contamination). 

2.Reporting and Public Notice 

Benzeoe............-.~ zero EPA also proposed reporting and 

Vinyl chloride Zero 

carbon tetrecMonde zero public notice requirements for VOCs in 1.2-D~loroethane......."......... Zero the November 1985notice. The proposed Trichloroethylene ......-"-..".... Zero A. Non-TransientNon-Community requirements were identical to those pDichlwobemene'......."........ 0.075 

1.1-Dichlwoelhylene .W7 currently in place under the National WaterSystems 

1.1.1-TricNwoelhsne..... ......... .20 Interim Primary Drinking Water In the November 1985notice, 

'~eproposedon Apll17.1987. at zero and 0.005. Regulations (now simply "National proposed to redefine the term 

Primary Drinking Water Regulations"). As described above, the Agency No change in the public notice 

proposed to amend the MCLG and requirements was proposed at that time. 

reproposed the MCL at 52FR 12876 For unregulated contaminants, the 

(April 17,1987)for para-dichlorobenzene proposed regulations would have 

(which is the common name for 1,4- required the PWS to notify its 

dichlorobenzene). These proposals were consumers of the availability of the 

based upon results of a new National analytical results of the unregulated Toxicology (NTP)study. Based on a contaminant monitoring and to submit a 

preliminary assessment of the total representative copy of each public

weight of evidence of the toxicological notice to the State. In addition, the 

studies, EPA proposed to reclassify p- results of the monitoring were to be 

dcb as a Group B2 substance under the submitted to the State. 

Agency's Guidelinesfor Carcinogen In response to the SDWA 

Risk Assessment at 51FR 33992 amendments of 1986,which revised the 

(September24,1986).This notice on p- public notification requirements in 

dcb also indicated that EPA was Section 1414(c), EPA recently proposed

considering classification of pdcb in changes to public notification 

Group C instead of B2.The Agency requirements in 52FR 10972(April 6, 

asked for public comment on the 1987).That proposal includes specific

appropriate classification based on the explanations of the potential health 

weight of evidence. risks of exposure to the eight VOCs in 

In the November 1985notice, EPA today's final rule. Those explanations

proposed to require non-transient non- were proposed to be required in each 

community water systems to meet the public notice for failure to comply with 

same requirements as community water any MCL. that the resource burden to the systems by broadening the definition of C.Public Comments on the Proposal "community water systems." This 

category of public water systems EPA requested comments on all 

includes such systems as schools and aspects of the November 13,1985, . 

factories where the same consumers proposal and the April 17.1987, 

may be exposed not only for part of the reproposal. A detailed summary of the 
No. 130 / Wednesday, July 8. 1987 / Rules and Regulations 25695 

FR 33992, September24,1986,for a full 

discussion on WASGuidelinesfor 

Carcinogenic Risk Assessment.) On 

November 13,1985,the Agency

promulgated an RMCL for p-dcb as a 

Group D substance, based on chronic 

toxicity data from the studies available 

at that time. 

After that notice was published, the 

Agency received the results of a longterm study on p-dcb conducted by the 

National Toxicology FVogram (NTP)

(Ref. 6).The NTP study was a chronic 

bioassay which used F344 rats and 

B6C3Fl mice. Tumors were found in 

both species of animals at incidences 

which were statistically significant.

Therefore on April 17,1987EPA 

reproposed the MCLG for p-dcb. The 

JPA proposed the MCLG consideringa 

classification of BZ for p-dcb but 

acknowledged the controversy

surrounding this classification and 

presented an alternative Group C 

classification. Public comments were 

solicited on whether p-dcb should be 

classified as a B2 or C substance. The 

conclusions of these comments received 

on this proposal differed even though

they were using the same criteria in the 

guidelines; eight commenters would 

place p-dcb in group C,two in Group B2. 

The Agency recognizes that as with 

most chemicals, the evaluation of the 

carcinogenicity potential of p-dcb in 

humans is a difficult and somewhat 

controversial activity, in light of 

divergent interpretations made by the 

scientific community. Because it is 

necessary for the Agency to make a 

judgment based on a reasonable 

weighing of the evidence from the data 

at hand, at this time pdcb is being

classified in category C (possible human 

carcinogen). 

At issue in the controversyof the 

classification is whether there exists 

"sufficient" evidence of carcinogenicity

(Le., B2 classification) or whether there 

is only "limited" evidence of 

carcinogenicity (Le. Group C). 

A Group B2 substance is defined by

the following factors: 

An increased incidence of malignant 

tumors or combined benign and 

malignant tumors in: 

(a) Multiple species or strains, 

(b) In multiple experiments (e.g.. with 

differentdose levels and routes of 

exposure) or 

(c) To an unusual degree in a single

experimentwith regards to a high

incidence, unusual site or type of tumor, 

or early age at onset. 

A Group C is defined by the following

factors: 

Having limited animal evidence of 

carcinogenicity in the absence of human 

data in which: 

(a) The studies involve a single animal 

species, strain or experiment and do not 

meet criteria for sufficient evidence. 

(b) The experimentsare restricted by

inadequate dosage levels, inadequate

duration of exposure, or inadequate

reporting, or 

(c) The studies show an increase in 

the incidence of benign tumors only. 

As pointed out in these Guidelines, 

this classification is not meant to be 

applied rigidly or mechanically, but a 

balanced judgment of the totality of the 

available evidenceneeds to be 

considered. This weight of the evidence 

approach can increase the number of 

reasonable interpretations to the same 

data base. 

Decision Process 

Evaluating the increased male rat 

kidney tumors and liver tumors in male 

and female mice of the NTP 1986 

bioassay, p-dcb might be tentatively

classified in Group B2 probable human 

carcinogen. However, when reviewing

the total weight of evidence at this 

juncture, pdcb could also be classified 

in Group C possible human carcinogen.

Factors relevant to determining weight

of evidence include: 1)evidence of 

carcinogenicity, 2) structurelactivity

relationships, 3) genotoxicity test 

findings, and 4) results of appropriate

pharmacokinetic and toxicological

observations. 

Because the carcinogenicity bioassays

(discussed under Evidence of 

Carcinogenicity)do not provide

unequivocal evidenceof carcinogenic

potential for humans, it is necessary to 

consider all factors in determining the 

weight of evidence for p-dcb

carcinogenicity. 

(I) Evidencefor Curcinogenicity.

Evidence for the carcinogenicity of 

p-dcb is primarily limited to the NTP 

study of F344 rats add B6C3Fl mice. In 

this study, rats and mice were exposed 

to two doses of pdcb in corn oil 

administeredvia gavage. The NTP 

concluded that there was clear evidence 

of carcinogenicity both for male rats as 

shown by an increased incidence of 

renal tubular cell adenocarcinomas and 

for mice of both sexes as shown by

increased incidencesof hepatocellular

carcinomas and hepatocellular

adenomas. No evidence of 

carcinogenicity was seen in female rats. 

The issue-ininterpreting the 

guidelines is to determine the relevance 

of both the male rat kidney and mouse 

liver tumors to human carcinogenesis. 
Inductionof male rat kidney tumors 

by several nongenotoxoc organic

chemicalshas been linked to the 

presence of hyaline droplets composed

of alpha-&-globulin, a protein which 

has not been detected in female rats, 

mice or humans. There is evidence for 

the formation of hyaline droplets in 

male rats given pdcb orally. It has been 

asserted by several investigators and 

commenters, and supported by

substantial data, that alpha-2u-globulin

is essential for hyaline droplets in the 

male rat kidney. Presence of hyaline

droplets seen only in the male rat 

kidney, which was the target organ in 

the NTP bioassay. and lack of hyaline

droplets in the female rat kidney, which 

was not a target organ, supports the 

hypothesis that hyaline droplets

formation may have limited significance

for human exposure to p-dcb. The 

mechanism of carcinogenesisis not 

absolutely certain but the involvement 

of alpha-Zu-globulin is a probable and 

sound scientific explanation that has 

been developed from a large body of 

mechanistic and pharmacokinetic

studies on this chemical. 

The significant increase in mortality

indicated that the MTD was exceeded 

for the high dose male rats. 

Diminished toxicological significance

might be ascribed to mouse liver tumors,

which are induced by a number of 

chlorinated hydrocarbons.As with 

tumors of the male rat kidney, theories 

have been proposed which argue that 

the mouse liver response is not relevant 

to humans. Explanations are still 

tentative and the possible relevance to 

human carcinogenicity is a current topic

of debate. 

Other bioassays have been performed

which although having some 

shortcomings conh the negative

results in the low dose NTP bioassay

results. Alderly Part Wistar rats were 

exposed to multiple doses of p-dcb via 

inhalation for 76 weeks, followed by an 

additional 36weeks of observation 

(Riley et al., 1980;described in Ref. 8).

No increases in tumor incidence or type 

were observed. Comparisonsof this 

study with the NTP bioassay are made 

difficult because of the differences in the 

route and duration of exposure.

However, if 0.1 liter/minute was 

assumed as the breathing rate for 500 

gram rats exposed to p-dcb for five 

hours/day, five dayslweek for seventysix weeks, the estimated daily oral dose 

would be 178mg/kg. This estimated 

dose is slightly higher than the low dose 

of 150mg/kg in male rats, which did not 

produce a significant increase in kidney 

tumors, as reported fromthe NTP study.

While the shorter duration of exposure 

may be responsible for diminished 

tumorigenic response, the variety of 

toxic effects (increase in liver, kidney,

heart and lung weights, increase in 

urinary protein and coproporphyrin

output) in the high dose group (500ppm)

indicate that the MTD was approached.

Subchronicstudies have 

demonstrated evidence of liver and 

kidney toxicity and a variety of other 

toxic effectsfrom pdcb exposure to 

animals either via gavage or inhalation 

(Hollingsworth, 1958,1958;described in 

Ref. 8). No evidence of carcinogenicity 

was found, but the short duration of 

these studies (&month duration)

precludes detecting carcinogenic effects 

unless the latency would be unusually

short and the compound were a potent

carcinogen.

No evidence of carcinogenicity in 

humans has been reported, which is not 

unusual. Therefore, inadequate data are 

available to assess the weight of 

evidence for carcinogenicity from 

epidemiological/casestudies in humans. 

Thus, consideringthe totality of 

evidence, the available bioassay data 

are equivocal as a basis for 

extrapolating to humans and the 

epidemiological data are inadequate. In 

the judgment of the Agency, a Group C 

classification for p-dcb would be more 

appropriate than a B2classification 

based upon the information currently

available. 

(2)StructumActivity. Compounds

with similar chemicalstructures have 

been tested in long-term carcinogenicity

bioassays, but no clear evidence of 

carcinogenicity has been reported. Such 

structure-activity information can be 

useful when evaluating closely related 

chemicals. 

Two compounds with similar 

structures to p-dcb

[orthodichlorobenzene(o-dcb) and 

monochlorobenzene (mcb)) have been 

tested in NTP bioassays. As with p-dcb,

the compounds were administeredin 

corn oil via gavage to F344 rats and 

B6C3K mice. Under test conditions, odcb was not carcinogenic at doses of 60 

and 120mg/kg administered for 103 

weeks. For mcb, an increase of 

neoplastic nodules of questionable

statistical significance was found for 

high-dose male rats (120mg/kg). Both odcb and mcb have been classified as 

Group I):inadequate evidencefor 

carcinogenicity.

Metabolites of p-DCB (2.5­

dichlorophenol and its hydroquinone)

have not been tested for carcinogenicity.

2,4-Dichlorophenol was administered in 

drinking water in a two-year bioassay in 

rats (Exonand Koller, 1985; described in 

Ref. 8) and found to produce n 

in tumors, but was cocarcin 

administered with e 

positive findings. but they do 

from the overall weight of evi 

carcinogenicity in this case. 

(3) Genotoxicity Tests.p-&b

determinednot to be genotoxic

variety of short-term genotoxici

bioassays. Therefore, it is less riq

that it could be carcinogenic by a 4 

genotoxic mechanism. GenotoxidG 

often associated mechanistically

carcinogenicity. Some non-genotd

substances are carcinogenic by

unknown mechanisms. 1 

p-Dcb is not mutagenic when ted 

SaImonelia typhimurium or in the J 

WP2 system. Increased frequency

back mutation was observed on th1 

methionine requiring forms in the 6 

Aspeqih nidulans, however this? 

finding is not considered signifid 

p-Dcb was not found to induce 4 

forward mutations in mouse lymph

cells, sister chromatid exchange ie: 

Chinese hamster ovary cells or 4 

unscheduledDNA synthesis in hum 

lymphocytes. Negative results wed 

obtained in cytogenicity studies Wn 

bone marrow cells and a dominant: 

lethal study in CD-1 mice followi$ 

exposure to p-dcb. 1 

8 (4) Pharmacokineticand i Toxicologicaal Observations. ‘ 

Commentem also raised questions

the relevance of the results of the 

bioassay to exposure of humans to$ 

DCB via drinkwater. Issuesinclude 

toxicological significance of the ma 

administration(gavage vs. drinking

water) and the vehicle used [corn 4 

drinking water). n 

With respect to both mode of 

administrationand vehicle, no data 

available specifically on pdcb, but 

bioassays on other chlorinated 

hydrocarbons have shown that the 

pharmacokineticsof absorption/

distribution differ between compoa

administered in corn oil via gavage

compared to drinking water 

administration. The issue that the c’ 

oil vehicle itself may affect hepatic

metabolic capabilities and influenct 

susceptibility of the mouse to hepat 

tumors has been a subject of 

controversy. No.data are available 

specifically on p-dcb. 
- 

/ Rules and Regulations 25697 

Section 1412(b)(5)of the Act defines 

"feasible" to mean "feasible with the 

use of the best technology, treatment 

techniques and other means which the 

Administratorfinds, after examination 

for efficacy under field conditions and 

not solely under laboratory conditions, 

are available (taking cost into 

consideration)," Le., "BAT." 

This provision represents a change

from the provision prior to 1986,which 

required EPA to judge feasibility on the 

basis of "best technologies generally

available" (I'BTGA"). The 1986 

amendments changed BTGA to BAT and 

added section 1412(b](5),which 

reference dose (0.1mglkg/ specifies that the technology selected as 

x body weight day)(7og] BAT must be tested for efficacy under - = 3.75 %/I field conditions, not just under DWEL = daily water 

consumption Wday 

drinking water equivalent level 

x relative source contribution 

additional uncertainty factor 

-= 0.075 mg/l (75 pg/l) 

the reference dose is calculated as: 

no observable effect level 

uncertainty factor 

Had p-dcb been assigned to Group ~2,

the 95%upper-limit carcinogenic 

potency factor for humans, ql*, would 

be the basis for the quantitation. A 

"what if' calculation for p-dcb, using the ' 

draft ql* value is 2x10'2(mg/kg/day)-l 

by the multistage model and male mouse 

liver tumor data indicated an upper-limit 

individual lifetime cancer risk of 4x10-5 

for a 70kg human L/water a 

day for a lifetime (assumed to be 7o 

years) exposure to drinking water 

containing75 pg/L. 

C.MCtSfor VOCs 

In this rule, EPA is promulgating

MCLs for the eight VOCs as follows: 

Benzene.-...- --.--I-.. I_.._."...-"._......._.".. 0.005 

vw -......-..I.-....- I.--...............-. 0.002 .. Ch-bLlntetreCMoride............... 0.005 

12-DicMoroemsna.... ............ ............ 0.005 

TricMwoethylene.-..-- ................................ 0.005 ??aene.-.-- ............................. ......"."".....................~ .......... 0.007

0.075 

1.1.1 -TricMaoemane......................... ~ ....._........ 0 2

I -

As noted earlier, section 1412@)(4) of 

the Act requires EPA to set MCLs as 

close to the MCLGs as is feasible. 

laboratory conditions. The legislative

history explains that CongreG removed 

the term "generally" to assure that 

MCLs "reflect the full extent of current 

technology capability." [S.Rep. No. 56, 

99th COW^ 1st sesS.1 at 6 (198511. Read 

together with the legislative history,

EPA has conchded that the 

term "best available technology" is a 

broader standard than "best technology generally available" and that this 

standard allows EPA to select a technologythat is not necessarily in 

widespread use, as long as it has been 

field 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 MCLs, EPA derives the MCLs 

from an assessment of a range of 

pertinent factors, including the 

availability and performance of BAT, 

the costs of these technologies for 

different size water systems, and the 

number of water systems that would 

have to install technologies. EPA also 

evaluates the availability of analytical

methods and the reliability of analytical

results as well as the resulting health 
256% Federal Register / Vol. 52, No. 130 Wednesday, July 8, 1987 1 Rules and Regulations 

risks of various contaminant 

concentration reduction levels 

attainable by BAT. Fordrinking water 

contaminants, the target reference risk 

range for carcinogens is lo-‘ to and 

most regulatory actions in a variety of 

EPA programs have generally fallen in 

this range using conservative models 

which are not likely tu underestimate 

the risk. Of course, MCLs could be set 

outside the range depending upon the 

feasibility of achieving a specific level. 

1.Treatment Technologies 

As explained in the November 1985 

proposal, EPA examined a number of 

treatment processes for their potential to 

reduce the level of VOCs in driwater. These technologies are discussed 

in the document ‘Technologies and 

Costs ForThe Removal of Volatile 

Organic ChemicalsFrom Potable Water 

Supplies.” (Reg. 2). (A draft of this 

document was available at the time of 

the proposal. The final document is 

available from the National Technical 

Information Service at the address listed 

in Section VI of this notice.)

in reviewing the different technologies

available, EPA looked at the following

factors: Removal efficiency, degree of 

compatibility with the other water 

treatment processes, service life, and the 

ability to achieve compliance for all the 

water in a public water system.

Based on these criteria, in the 

November 1985 notice, EPA proposed

granular activated carbon (GAC) and 

packed tower aeration (PTA) as “best” 

technologies for removing VOCs from 

drinking water. As described in that 

notice (50 F’R 46914). these technologies

have the following characteristics: good

removal efficiencies (90to 99percent):

compatibility with other types of water 

treatment processes: reasonable service 

life: and ability to achieve compliance

for all the water in a public water 

system. In addition, these two 

technologies are commercially available 

and have been used successfully to 

remove VOCsin ground water from 

both influents and effluents in many

locations across the United States. 

In the 1986 amendments to the Safe , 

Drinking Water Act, Congress specified

in section 1412(b)[5)of the Act 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. 

For all the VOCs except vinyl

chloride, EPA has-identified GAC as 

technology that is effective for removing

VOCs. PTA is equally effective. 

Therefore, these two technologies are 

“best” for these seven VOCs.PTA is 

more effective than GAC for vinyl

chloride, as noted below. 

Vinyl chloride differs from the other 

VOCs because it is a gas under typical 

temperature and pressure conditions. 

Therefore, vinyl chloride is most easily

removed by PTA treatment. Because 

vinyl chloride is a gas and a known 

human carcinogen, no laboratory

isotherms have been developed by EPA 

or reported in the literature. However, 

one investigator reported sporadic

removal of vinyl chloride from ground 

water in Florida using GAC (Symons,

1978). This investigator also noted that 

vinyl chloride was the only one of a 

number of related, low molecular weight

VOCs to show such an erratic pattern. A 

more recent, unpublished study of 

ground water in Wisconsin @PA, 1987)

showed less erratic removals at a higher 

empty bed contact time and lower raw 

water concentrations. It is difficult to 

interpret either of these studies. 

Therefore, because PTA has been 

demonstrated to be extremely effective 

and GAC may, under some 

circumstances, exhibit poor or erratic 

removal, EPA is not specifying GAC as 

“best” for the removal of vinyl chloride. 

ITA, however, is “best” for removal of 

this contaminant. 

Also,it should be noted that the data 

used to determine removal efficiencies 

were based on performance for ground 

water. EPA expects that GAC, applied 

to surface water, would achieve lower 

performance efficienciesbecause of the 

higher levels of organic carbon found in 

surface water which cause more rapid

depletion of the capacity of the GAC 

(ground waters typically have very low 

levels of background organic carbon)

(See Reference 2).

In addition to GAC or FTA, there are 

other technologies which may remove 

VOCs from drinking water, e.g., resins,

powdered activated carbon. However, 

EPA, has concluded that these 

technologies are inferior to GAC and 

IJTA for various reasons, e.g., the 

technology is not commercially

available or the removals are lower 

and/or less consistent. For a further 

discussion of other technologies EPA 

considered, and why they are not 

designated as “best,” see WAS 

technology and cost document 

(Reference 2). 

2. costs 

As noted above, EPA is to set the 

MCL as close to the MCLG as 

(Reference 2). 

treatment cost estimates are . 

“feasible,” which is defined as “feasible 

with the use of the best technology. . . which the Administrator finds . .is 

available (taking costs into 
Federal Register Val. 

VOCs,see the November 1985notice (50

FR 46911, November 13,3985). 

For contaminants with MCLGs set at 

.a non-Zero level (substances in 

'concentration in principle.cannot be 

achieved. In the MCLsetting process,

therefore, EPA evaluates the feasibility

of achieving levels as close to zero as 

feasible.Based on the costs and the 

.availability/performanceof treatment 

describedabove, EPA has concluded 

that GAC and PTA are BAT [except that 

-GACis not BAT for vinyl chloride. since 

it is not the "best" technology). 

To determine,whatlevel was feasible 

as BAT,EPA examined the total 

'compliance costs at various levels of 

,dontamination(as well as the individual 

compliance costs summarized above).

For all the contaminants with MCLGs at 

to install treatment at a total 

trichloroethylene, carbon tetrachloride. 

1.2-dichloroethane. and benzene at a005 

mgll. For vinyl chloride, EPA has set the 

MCL at 0.002 mg/l. This lower level 

reflects the treatment capability of PTA 

that would be used to remove vinyl

chloride, and it is not expected to result 

inany increased cost over an MU of 

0.005 mg/L EPA believes that very few, 

if any, public water systems will need to 

install treatment solely to control vinyl

chloride. Because systems with vinyl

chloride present at any level virtually

always have one or more of the other 

VOCs covered by this rule present at 

levels higher than the promulgated MU 

for these VOCs.these systems will be 

treating their water to comply with the 

MCLs applicable to those other VOCs 

and the same treatment (FTA) will also 

remove the vinyl chloride to 0.002 mg/l.

PA estimates the total compliance 

costs to meet the eight MCLs at $300 

million (total present value costs) and 

$22.5 million (total annual costs) (See

Ref. 3, "Economic Impact Analysis of 

Proposed Regulations"]. EPA estimates 

the annual cost per family to be $41 per 

year for a small system, $12per year for 

a medium system, and $3 per year for a 

large system. 

3. Other Factors 

The other factors EPA examined 

support its MCLdeterminations. They 

are explained below. 

AnalyticalMethods. The Agency also 

examined the analytical methods 

available for the measurement of 

volatile organicchemicals in drinking 

water and summarizedits findings in the 

November 1985 notice. Based on this 

review, the Agency has determined that 

analytical methods currently exist 

which can reliably measure VOCs in 

drinkingwater. In addition, EPA has 

concluded that the cost of sample

analysis at intervals necessary to assure 

detection of MCLviolation is 

economically feasible for all public 

water systems. Costs are estimated to 

be approximately$150 to $Zoo per

sample analysis. Further discussion of 

available analytical methods is included 

in the section on compliance monitoring.

The MDL is the minimum concentration 

of a substance that can be measured 

and reported with 99 percent confidence 

that the true value is greater than zero. 

These MDLs are the result of 

measurementsmade by a few of the 

most experiencedlaboratories under 

non-routine and controlled ideal 

research-type conditions. 

MDh and PQLs. The MDL is used by

individual laboratories to determine the 

laboratory-specificminimum detection 

capabilities. EPA has gathered 

I Rules and Remlations 256% 

information indicating that laboratories 

in general are able toachieve MDLs of 

0.m mgll or lower with the available 

VOC methods (Ref. 1). Specifically,

under single-laboratory,ideal 

conditions. the method detection limits 

(MDLs) of the eight VOCshave been 

determined to range from 0.0002 to 

OD5 mg/l. 

In the November 1985proposal, FPA 

defined the "practical quantitation

level" (PQL) as the lowest level that can 

be reliably achieved within specified

limits of precision and accuracy during

routine laboratory operating conditions. 

PQLB thus represent a level considered 

to be achievable on a routine basis. The 

basis for setting PQLs is.(l) quantitation, 

(2) precision and accuracy, (3) normal 

operations of a laboratory, and (4) the 

fundamentalneed (in the compliance

monitoring program) to have a sufficient 

number of laboratories available to 

conduct the analyses. 

The PQL is analogousto the limit of 

quantitation (LOQ) as defined by the 

American Chemical Society. Both the 

LOQ and the PQL define the 

concentrationof an analyte above 

which is the region of quantitation and 

below which is the region of less certain 

quantitation. The difference is that 

where the PQL is an inter-laboratory 

concept whiIe the LOQ is specific to an 

individual laboratory. The Agency

developed the PQL concept to define a 

measurement concentration that is time 

and laboratory independent for 

regulatory purposes. The LOQ and 

MDk although useful to individual 

laboratories, do not provide a uniform 

measurement concentration that could 

be used to set standards. 

PQLs for the VOCs were determined 

based on the MDL and surrogate test 

data. In the past, EPA has estimated the 

PQL at five to ten times the MDL and, in 

the November 1985notice, EPA 

suggested setting PQLs at this general 

range. In the notice �PA used the results 

of inter-laboratory studies to confirm 

this estimate. The PQLs based on these 

laboratory data are considered a "twostep removed" surrogate for actual 

laboratory performance, first because 

they are estimatedfrom another 

measurement (the MDL) and second, 

because they are derived From 

laboratory performance under ideal 

circumstances. Therefore, they do not 

actually represent the results of normal 

laboratory procedures,but are a model 

of what normal procedures might

achieve. Specifically: 

(1)Laboratoriesreceive performance

evaluation samples in which a limited 

number of concentrations are analyzed 
25700 Federal Register / Vol. 52, No. 130 / Wednesday, July 8, 1987 / Rules and Regulations -%.. 

-3 

and the samples do not have matrix 

interferences as might actual samples: 

(2)PQLs are based on EPA and State 

laboratory data which are considered to 

be representative of thebest 

laboratories, but not all laboratories: 

and 

(3) Samples are analyzed under 

controlled ideal testing conditions which 

may not be representative of routine 

practice.

For these reasons, the PQL represents 

a relatively stringent target for routine 

performance. EPA expects that the PQLs

in this rule will push laboratories to 

perform at a higher level than they

would otherwise. In the range between 

the MDL and the PQL, quantitation of 

contaminants can still be achieved, but 

not necessarily with the same precision

and accuracy possible at the PQL.As 

measurements approach the MDL, there 

is much less confidence in quantitation.

Thus, PQLs set a target performance

level for laboratories using a specified 

set of precision and accuracy

limitations. In this manner, PQLs 

provide consistencyin implementing a 

regulatory program, in a practical way,

where both quality control and quality 

assuranee is critical. 

Most,commenters agreed with the 

PQL concept; however, several stated 

that the PQLs should be verified further 

through additional multi-laboratory

studies. For instance, several 

commenters were critical of the PQL for 

vinyl chloride, stating that the level 

should be based on multi-laboratory

data as opposed to simply being set at a 

value of five times the MDL. EPA agrees

that the PQLs should be further verified 

as explained in Reference 1,the Agency

collected additional multi-laboratory

data including data on vinyl chloride, 

and used these data to set the final 

PQLs. 

One commenter felt that PQLs should 

be replaced with the LOQ concept as 

described above. EPA does not agree

that the PQL should be set based upon

the LOQ because the LOQ is dependent 

on the precision attainable by a specific

laboratory, which can vary from day to 

day as well as among laboratories. 

Thus, the LOQ is not designed to assess 

the performanceof a large number of 

good laboratories: instead, it is 

laboratory-specific and therefore is not 

suitable for setting criteria for national 

standards. 

Some commenters stated that the 

PQLs were set at too high a level and 

suggested 0.001 mg/l, while others 

believed that the PQLs were too �ow. A 

PQL range from 0.02 to 0.04 mg/l for 

benzene was suggested by one 

commenter. 

EPA disagrees with the comments that 

the PQLswere set at the wrong level; 

the levels were selected based on multilaboratory data which confiied the 

general rule of five to ten times the 

MDL. Setting the PQLs at higher or 

lower levels would not be consistent 

with the data. EPA recognizes that many

laboratories have reported data at levels 

less than the PQL;however, the Agency

does not consider the data sufficient 

upon which to base national standards 

consideringthe other data available. 

Again, PQLs provide for consistencyin 

data quality from a diverse group of 

laboratories across the country, and 

provide routine performance goals that 

many laboratories must strive to 

achieve. 

As explained in Reference 1.the PQLs 

are 0.005 mg/l for all the VOCs except

vinyl chloride. EPA generally based the 

PQLs upon a laboratory performance

criterion of k20 percent or 40percent,

depending on the concentration, for 

each individual VOC except for vinyl

chloride which was +apercent. This 

provides a relatively stringent

performance target for laboratories but 

one that has been demonstrated to be 

achievable by three-quarters of the 

"best" @PA and State) laboratories 

under evaluation conditions. It is 

expected that the remaining laboratories 

will need to upgrade their performance

in order to meet this criterion. For vinyl

chloride, the PQL is 0.002mg/l (rounded

from 0.0015 mg/l for the reasons 

discussed in Reference 1).The PQL of 

0.002 mgll recognizes that on the one 

hand the precision/ accuracy associated 

with measuring vinyl chloride is 

expected to be less than for the other 

VOCs; but that, on the other hand, vinyl

chloride is a known human carcinogen

of high potency and the risk posed by

each unit of exposure could be higher

than for the other VOCs. Because of this 

latter factor, EPA believes it is 

appropriate to accept slightly less 

precise data in order to seek to obtain 

more stringent levels of control. 

Technical assistance to laboratories that 

wish to be certified to analyze vinyl

chloride is available for EPA-EMSL in 

Cincinnati. 

For each VOC, the PQL is equal to or 

less than the MCL. Therefore,

laboratories will be able to reliably

determine whether systems are in 

compliance with the MCLs. 

Health Risks.PA examined the 

theoretical maximum health risks 

expected at various contaminantlevels. . These health risks include non-cancer 

risks, as well as cancer risks. The upperlimit unit risk estimates from the animal 

'data are derived from a linearized multistaged nonthreshold extrapolation 

model that is currently programed ai 

GLOBAL83. Justification forits use is: 

presented in EPAs Guidelines for

Carcinogenic RISK Assessment. Wh&,; 

recognizing that alterna live statistical' 

modeling approaches exist (e.g., one& 

Weibull, log-probit and logit models, . and maximum likelihood estimates),a 

range of risks described by using any

these modeling approaches has little .; 

biological significance unless data caq

be used to support the selection of one. 

model over another. In the interest of:; 

consistency of approach and of 

providing an upper bound estimate for 

the potential cancer risk, the Agency :-,

recommends the use of the linearized,.l

multistage model. EPA considers this :,

model and resulting risk estimates to b 

an upper-limit value in the sense that 

the true risk is unlikely to be higher ani 

may be lower. An established procedw

does not yet exist for making "most 

likely" or "test" estimates of risk wi& 

the range of uncertainty derived by the 

upper and lower limit values. ,. , 11 

Table 2presents sample risk . .$ 

estimates calculated at the 95 percent-:

confidence limit using the multi-stage ; 

model for the five VOCs which are I . considered known or probable human: 

carcinogens. EPAs Carcinogen -,! 

Assessment Group (CAG) cakculated I;

these numbers based on the assumptior

.of two liters of water ingested dailypy 

a lifetime of 70years for a person .. weighing 70 kilograms (kg). The Agenc]

calculates these risk estimates so that I 

they are not likely to underestimatethe 

actual risks, and are conservatively :.: 

used to evaluate "worse case" scenaric 

for the purpose of regulatory-impact analysis. ..:I 

TABLE2-AN EXAMPLEOF UPPER BOUND LIF 

TIME CANCER RISK (10'6) ESTIMATESF( 

VOCS CATEGORIZED AS KNOWNOR PRO,? 

BE HUMAN CARCINOGENS 

'Risk &Is are best representedby one mnt &7 

because ol lhe imprecise natured the I@ rodeleXaspP Ions. 

"Ca~lation ""8 pr- ncldyes.lf Preww 

nodules we not actwed into the nsk assessmenr I estimaledriskallO~l;sO.OZmgll. . . . . I :.'I 

As mentioned above, for 

contaminants in drinking watkr, the 

target reference risk range for 

carcinogens is 10-I to 10-.and the, .,:

MCLs EPA is promU1gati.q in this no@' generally fall in this'range. EPA ' 

considers these to be safelevels and 
52, No. 130 1 Wednesday, July 8, 1987 

considers the MCLs determined 

ssary contaminationand to 

ate that treats all of the water and 

through indoor air transport (e.g.. from 

showers or dermal contact). In addition, 

these devices are generally not 

affordable by large metropolitanwater 

systems,which is one of the criteria for 

setting BAT. 

In the November 1985notice, the 

Agency discussed its proposal to not 

allow PWSs to use bottled water for 

compliance or to meet conditions of 

variances and exemptions. Public 

comments pointed out that bottled water 

may, in a few cases, be the only

available "treatment technique" for the 

the smallest systems. The Agency

restated in its April 1987 notice that 

bottled water was not an acceptable 

means of meeting the M U requirements 

on a permanent basis since it does not 

provide the same level of protection as 

central treatment (i.e., persons may

choose not to drink bottled water) and 

bottled water might allow significant 

exposure to water which does not meet 

the drinking water standard during

showering and other applications.

However, in that notice, EPA 

proposed that bottled water be allowed 

as an interim measure to prevent an 

unreasonable risk to health during the 

time between detection of an Ma 

violation and achievementof 

compliance; it is emphasized that 

provision of bottled water during this 

interim period does not bring the PWS 

into compliance with the MCL; bottled 

water does, however, provide an 

acceptable source of water to drink 

during the interim period. In a future 

notice, EPA will further assess the 

advisability of allowing some NTNCWS 

and very small systems to use bottled 

water to meet the MCL requirements.

The majority of commenters agreed

that POU/POE devices and bottled 

water should not be considered BAT, 

and that the NPDWR should not allow 

their use for compliance with MCLs, due 

to difficulties in controlling installation, 

maintenance, operation, repair, and 

potentisl human exposure via untreated 

taps. However, other commenters stated 

that POU/POE devices and bottled 

water should be consideredBAT or 

allowed for compliance, as these 

technologies were often more costeffective for some small systems than 

central treatment. 

In this final rule, POEand POU 

devices are not designated as BAT 

because: (1)It is significantly more 

difficult to monitor the reliability of .~

treatment performance and to control 

the operation of POE and POU devices 

in a manner comparable to central 

treatment; (2) these devices are 

generally not affordable by large

metropolitan water systems; and (3) in 

1 Rules and Regulations 257tU 

the case of POU devices. not all water is 

treated. In addition, under this rule, POU 

and bottled water are not considered 

acceptable means of compliance with 

MCLs. These devices do not treat all the 

water in the home and could result in 

health risks due to exposure to 

untreated water. Consequently, POU 

devices and bottled water are only

considered acceptable for use as interim 

measures, e.g., as a condition of 

obtaining a variance or exemption, to 

avoid unreasonable risks to health 

before full compliance be be achieved. 

Under this rule, however, POE devices 

are acceptable means of compliance,

because WE provides drinking water 

that meets the standards throughout the 

home. These devices may be costeffective for small systems or nontransient non-community water systems

(for which these devices wouM often be 

essentially the same as central 

treatment), although operational

problems may be greater than for 

central treatment in a community 

system. 

The SDWA requires EPA to establish 

necessary oonditions for use of 

treatment that will assure protection of 

public health. Specifically, section 

14Ol(I) of the Act states that primary

drinking water regulations are to 

contain "criteria and procedures to 

assure a supply of drinking water which 

dependably complies

with . . .maximum contaminant levels, 

including quality controland testing

procedures to insure compliance with 

such levels and to insureproper

operation and maintenance of the 

system." Accordingly, this rule imposes

the following conditions on those 

systems that use POE for compliance: 

(1)Centml Control.The public water 

system will be responsible for operating

and maintaining all parts of the 

treatment system (i.e., the treatment 

device). Central ownershipis not 

necessary, as long as the public water 

system maintains control of the 

operation of the device. Central control 

is appropriate and necessary to ensure 

that the treatment device is kept in 

working order. 

(2) EffectiveMonitoring.As 

monitoring the quality of a PWS 

drinking water is a central part of 

ensuring compliance with any NPDWR,

the public water system must develop a 

plan and obtain State approval for a 

monitoring plan before it installs the 

POE devices. Because POE devices 

present a fundamentally different 

situation than central treatment, a 

unique monitoring plaq must be 

developed. This monitoring plan must 

ensure that the POE devices provide 
I

25702 Federal Register / Vol. 52, No. 130 I Wednesday, July 8, 1987 / Rules and Regulations 

health protection equivalent to centra1 

water treatment. Equivalent means that 

the water would meet all Primary and 

Secondary Drinking Water Standards 

and would be of acceptable quality

similar to water distributed by a well 

operated central treatment plant. In 

addition to the VOCs. monitoring must 

include physical measurements and 

observations, such as total flow treated 

and the mechanical condition of the 

treatment equipment. 

(3)AppIication ofEffkctive 

Techeology There are no generally

accepted standards for the design and 

construction of POE devices, and there 

are a variety of POE designs available, 

Therefore, the State must require

adequate certification of performance,

field testing, and, if not included in the 

certification process, a rigorous

engineering design review of each type

of device. Certification can be done by

the State or by a third party acceptable 

to the State. 

(4)Maintenance of the 

Microbiological Safetyof the Water. 

The design and application of POE 

devices must,considerthe tendency for 

increases in bacterial concentrations in 

water treated with activated carbon and 

some other technologies. It may be 

necessary to use frequent backwashing, 

post-contactor disinfection, and 

monitoring to ensure that the 

microbiological safety of the water is 

not compromised. EPA considers this 

condition necessary because 

disinfection typically is not provided

after point-of-entry treatment as is 

normal is used in a central treatment 

plant.

(5)Protectionof AN Consumers.Every

building connected to a public water 

system must have a POE device 

installed, maintained, and adequately

monitored If the building is sold, the 

rights and responsibilities of the utility 

customer must be transferred to the new 

owner with the title. 

E. Analytical Methods and Compliance Monitoring Requirements \ 

1.Analytical Methods 

In the November 1985notice, the 

Agency proposed the use of three 

analytical methods that it considered 

economically and technologically

feasible for monitoring compliance with 

the VOC MCLs. These methods were: 

(1)EPA Method 502.1,“Volatile 

Halogenated Organic Compounds in 

Water by Purge and Trap Ga$ 

Chromatography.“ 

(2)EPA Method 503.1,“Volatile 

Aromatic and Unsaturated Organic

Compounds in Water by Purge and Trap

Gas Chromatography.” 

(3)EPA Method 524.1,“Volatile 

Organic Compounds in Water by Puqe

and Trap Gas ChromatographylMass

Spectrometry.”

Capillaw Column Techniques.Same 

commenters recommended the use of 

capillary column techniques for VOC 

analyses. The Agency evaluated 

capillary column methodology and 

agreed that they are available. Some 

commenters also recommended the use 

of detectors in series to analyze

purgeable halocarbons and aromatics 

simultaneously. The Agency agrees and 

has developed Method 502.2,which 

provides for the use of detectors in 

series, and proposed capillary column 

analytical methods at 52FR 12879(April

17,1987).This final rule includes the 

capillary column methods as approved

analytical methods: 

(I]Method 524.2,“Volatile Organic

Compounds in Water by Purge and Trap

Capillary Column Gas Chromatography/

Mass Spectrometry.” 4)Method 502.2,“Volatile Organic

Compounds in Water by Purge and Trap

Gas Chromatography with 

Photoionization and Electrolytic

Conductors in Series.” 

Disapproval of the 6wSeries 

Methods. In addition, on May 27,1986 

(52FR 19076),EPA requested comment 

on whether to approve the 600series 

methods (i.e., EPAs analytical methods 

for detecting volatile synthetic organic

compounds in wastewater, Methods 601. 

602,and 624in 40CFR Part 136)for 

compliance monitoring since a number 

of comments to the November 1985 

notice suggested they be approved as 

well. 

EPA has evaluated the comments and 

determined that the 600series methods 

are technically very similar to the 500 

series methods (e.g., the analytes

covered, and the analytical columns,

detectors, and chromatographic

conditions are the same). However,FPA 

has determined that the methods are not 

interchangeablefor various reasons. 

First, their analytical objectives are 

different. The 500series methods 

emphasize detectability at low levels 

while the 600 series methods do not 

focus on measurements near the MCLs 

(the sample volume is 5ml in Method 

624 versus 25 ml in Method 524.1).

Second, the specific quality control 

requirementsthat must be met for the 

500series and the 600series methods 

are different. The performance criteria 

specified in the 500 series methods are 

more stringent than those in the 600 

series methods. For example, the 500 

series methods include a requirement

that laboratories analyze quality control 

standards within 60 and 140percent of 

the expected value, while the 

methods are not designed to maximize . 

detectability at low levels and do not 

have as stringent performance criteria, , as do the 500series methods. 

1983(48FR 45502), and further discuss 

in the November 13,1985,VOCEMCL :-

proposal (50FR 46902). Tier II . 

contaminants are thosewhich are of . 

sufficient concern to.warrantnationa1 

regulation (i.e.,.MCLs Dr treatment .... 

technique requirements) but which.. 

occur with limited frequency, therefore: 

justifying flexible national minimum 1.’ 

-monitoringrequirements to be applied

by the State. :.:. ,. . ,: - . . 

. . 
s 

he 

600 

!? 

ze 

t 

ia, 

ants 

3. 

blic 

ing

?ncy

ier 

issed 

:L 

f 

.a1 

Ore. 

1 

ed 

e 

(50

)r the 

S 

”­. . 

ter 

3e 

ry

-face 

nts 

ine 

mple 

:r for 

ems; 

to 

s for 

vere 

3W1,

Id be 

:r 

nduc 

;ed 

the 

Federal Register 1 Vol. 512, No. 130 I Wednesday, July 8, 1987 

sampling for systems with wells that 

only operate a few months a year. Other 

commenters recommended that the 

vulnerability assessment be included as 

part of the sanitary survey which is 

conducted every three years under the . current TWDWR .for colifwp, rather 

than annually. Gommenters supported

the provisions for “grandfathering”

previous data in lieu of new data for the 

initial round of monitoring.

In this final regulation, EPA has 

retained the majority of the monitoring

requirements described in the preferred

option (Option 2). In the final regulation,

EPA is requiring that all community 

water systems and NTNCWs conduct an 

initial round of monitoring to determine 

the extent of contamination of water 

supplies. All size systems must monitor 

as the occurrence data collected by EPA 

indicate that systems of all sizes have 

detected VOCs at relatively high

concentrations, sometimes without 

apparent sources of contamination. In 

general, the likelihood of contamination 

increases with population, since areas of 

large commercial or industrial activity 

are often located in large population 

centers. The Ground Water Supply

Survey of 1982 (Ref. 7)found that 16 

percent of the smaller systems (<10,0oo

people) and 28 percent of the larger 

systems (>lO,OOO people) had 

detectable VOCs .EPA believes that 

phasing in the monitoring requirements

by system size is reasonable because of 

the greater vulnerability of the large 

systems and because these systems can 

more easily handle the monitoring costs 

associated with this regulation. In 

addition, phasing in the requirements 

over a four-year period will allow the 

analytical laboratories to develop the 

capability to handle the additional 

samples. This is consistent with 

previous regulatory actions 

implementing the Safe Drinking Water 

Act (eg., trihalomethanes).

EPA has modified the sampling

locations for surface water systems such 

that samples can be taken after 

treatment from entry points to the 

distribution system taps that are 

representative of each source. 

EPA investigated the feasibility of 

compositing samples for VOC analyses

in an effort to reduce the monitoring 

costs. Samplecompositing could then be 

used as a screening test to determine 

whether samples from multiple sampling

sites may be contaminated by VOCs. 

EPA investigated composites of 5 

different samples since a concentration 

in the original sample above the PQL 

(and the MCL for some VOCs) should 

still be detectable but not quantifiable in 

a composite sample resulting from such 

dilution, for example, if one of the five 

} Rules and Regulations 25703 

samples were contaminated at 0.005 

mg/1 and the other four were zero. 

Reanalysis of each sample would be 

required if VOCs were detected in the 

composite sample. The experiments

conducted by EPA were done to 

determine whether sample-compositing

would work for the VOCs (i.e., whether 

VOC losses could be kept to a 

minimum), and to determine the 

technique most appropriate to minimize 

VOC losses. 

The experiments conducted involved 

the preparation of composite samples

for GC and GC/MS analyses.The

procedures investigated for each type of 

analysis were different because of the 

difference in sample size (5ml sample

purged for GC analyses: 25-ml sample

for GC-MS analyses). The compositing

technique that worked best for GC 

analyses involved the addition of five 5­

ml samples to a 2Sml glass syringe and,

after mixing, drawing out a 5-ml aliquot

for analysis. The mixing should be done 

with the sample cooled at 4” C to 

minimize VOC losses. Data collected for 

five replicate samples demonstrated 

excellent recovery for all compounds

(9.5-100 percent) with good precision,

generally 33percent relative standard 

deviation. The recommended 

compositing technique for GC/MS

analyses involves the injection of 5 ml of 

each sample directly into the purge -

device. For most components, recoveries 

were greater than 85 percent with good

precision, generally between 3-5 percent

relative standard deviation (Reference 

1).

Based on this information, procedures

for compositing samples are included in 

the regulations. Several points are 

briefly addressed below. Samples are to 

be collected from each source and 

shipped to the laboratory where they

will be composited. Compositingis not 

done in the field. Public water systems

and States that collect samples must be 

aware that there are some potential

problems that should be kept in mind 

when they composite samples. It is 

desirable that sampling schedules be 

arranged in a manner that provides for 

collection of all samples to be 

composited the same day. Sample

preparation and analysis must take 

place within the maximum holding time 

of 14 days. The samples collected are 

shipped to the laboratory where the 

analyst will prepare a composite sample

from a series of discrete samples. This 

additional sample preparation step

provides more opportunity for the 

introduction of recordkeeping errors so 

additional care must be taken. EPA 

recommends that all samples be 

collected in duplicate to provide an 
25704 Federal Register I Vol. 52. No.130 1 Wednesdav. Tulv 8. 1987 

additional sample in case VOCs are (2)The repeat compliance monitoring detected in the composite sample. This requirementsfor those systems that the 

would avoid the need to resample at State determines are vulnerablebut in 

each sample siteto determinewhich which no VOCswere found in the initial 

site(s) may be contaminated.If VOCs sample, are based upon system size [see 

are detected in the composite sample, Table 4).

the original samples cannot be (3) For systems finding two-carbon 

reanalyzed because of head space VOCs, vinyl chloride analysis is 

problems created when the first aliquot required. If vinyl chloride is not detected 

was taken. Reanalysis must be in the initial sampleStates can reduce 

conductedfor each of the duplicate monitoring frequencies to once every samples, provided the maximum storage three years for vinyl chloride. 

time of 14 days has not been exceeded. ASfor comments recommending that 

Resampling must be done immediately EPA reducesampling for systems with 

where one or more VOCs are detected if wells that only operate a fewmonths a 

no duplicates are available. year, the Agency believes that any such 

The greatest limitation of compositing reduction is appropriate. Under thisfinal 

samples from different sources is that rule monitoring is required for all wells,

the analytical results will not actually including backup wells, only when they provide a measurement ofwhat is in the are being used. For example,four 

water if the composite sample turns out quarterly samples would not be required 

to be negative. It is possible that some for wells that are only used for say two 

VOCs may be present at trace levels months per year; however, a sample

and will not be detected in a composite each quarter that the wells operate sample. Therefore, sample-compositing would be needed. 

is not thepreferred approach but one The Agency agrees with the 

that can be used when monitoring costs recommendation that the State make a 

add a significant economic burden, with vulnerability assessment once every recognition of its limitations. three years rather than every year as 

Confirmation samples of positive proposed. In addition, EPA believes that 

results can be required by the State: the State should make a vulnerability

results of confirmation samples must be assessment (~500connections)every

included in the quarterly average along five years only. These changes are 

with the initial sample. States, however, reasonable because it is unlikely that 

have discretion to delete obvious significant undetected changes would 

analytical errors in the initial or occurin the vulnerability ofa system

confirmation samples. in addition, sufficient to result in sufficient VOC 

States have discretion to require contaminationwithin a one- to two-year

additional monitoring samples: results of time period. The final rule reflects these 

all samples must be included in each changes.

respective quarterly average (except as EPA also proposed the following noted above for obvious errors). method for determiningcompliance:

EPA modified some of the monitoring (1)All quarterly compliance samples

requirements it proposed in the would be collected un the same day and 

November 1985notice to address the analyzed according to procedures 

concern of many commenters regarding promulgated in -this rule. 

monitoring costs. These changes are (21 Compliance with the MCL would 

summarized Below and further be computed by runningarithmetical 

discussed in the Methods and average of the past four quarterly

Monitoring document (Ref. 1). samples. 

(1)The number of samples required (3) Compliance would be determined 

for groundand surface water systems for each sampling location; if water at 

has been reduced from the number that location was above the MCL, the 

proposed. The rule allows composite entire system would be deemed out of 

samples of multiple sampling sites [up to compliance and public notice would be 

five samples), resulting in lower costs. sent to all customers served by the 

Whenmonitoring costs would create an system unless there was no inter-mixing

unacceptable financial burden,States of source waters in distribution. 

that conduct the monitoring themselves EPA received a number of comments 

can composite samples from different on the proposed method of determining 

systems. This may be particularly compliance. Many commenters 

beneficial for monitoring non-transient supported the methods, while other 

non-community water systems. As commenters believed that only that 

proposed, under the final rule, if VOCs portion of the system exceeding the 

are detected in a composite sample, MCL should be considered out of 

follow-up analysis is required for each compliance and that public notification 

source (see discussion of composite should be limited to the affected 

samples). consumers. EPA believes that it is often 

1 Rules and Regulations 

not possible to determine the specific 

have a clearly definable distribution 

system from a source wifhno 

interconnections to any other source. TO 

accommodate these different situations, 

EPA is .promulgatingthe requirements . . 

for determining compliance and public

notification as proposed, except that the 

State may determine that only one 

segment, is.,the affected part of a 

public water system, is out -of 

compliance and :hit public notification 

to that one segment 

provision. Since the 1986Amendments 

to the SDWA allow use of data for 

unregulated contaminants back to 

January 1,9983,'EPAfeels it appropriat 

to allow States discretion to alsouse 

classified.as "vulnerable" and the fin 

sample)if the compositesreflect 
7 / Rules and Regulations 2m5 

tetrachloroethylene, cis-1,zdichloroethylene, or trans-l,Zdichloroethylene). 

(6)All systems to which the 

(7) These requirements are . . 

summarized in the table below: 

. , 

I? LabomtoryApproval 

EPA’s existing rules in 40CFR 141.28 

require that analyses for compliance

monitoring purposes be conducted only

by State-approvedlaboratories. 

Laboratorieswishing to obtain approval

for conducting VOC analyses must 

successfullyanalyze performance

evaluation samples within the limits 

established by EPA and meet other 

requirements. The acceptance limits for 

laboratory approval are derived from 

the performance evaluation study data,

Le., the Water Supply Study series. 

EPA requested comment on the use of 

a “plus or minus percent of true value” 

approach for setting performance

criteria (Le., acceptance limits). Most 

commenters supported the use of a “plus 

or minus percent” approach to derive 

acceptance limits over generatingthem 

from study statistics based upon 95 

percent confidence limits. Some 

commenters believed, however, that the 

specific acceptance limits proposed 

were too strict and there would be an 

insufficient number of laboratories 

available that could meet such 

standards. EPA disagrees with this 

comment because the most recent water 

supply performance evaluation study

showed that about 85 percent of all data 

submitted to FPA and State laboratories 

and about 70percent of the other 

participating laboratories were within 

the proposed acceptance limits. These 

results compare favorably with other 

regulated contaminantswhere, even 

after years of experience, only 80-85 

percent of all the data submitted are 

within the acceptance limits for each 

study. A specific example is the 

trihalomethanes, where about 85percent

of the data submitted by EPA and State 

laboratories and about 75percent of the 

data submittedby other participating

laboratories are within the established 

limits. The actual percentage varies 

somewhat from study to study. 

The acceptance limits were proposed 

to be +40 percent of the true value for 

concentrationsless than 0.010 mg/l, and 

220 percent of the true value for 

concentrations of 0.010 mg/l or above 

for all of the VOCs except vinyl

chloride. More recently, data from 

Water Supply Study No. 17,at 51 FR 

19077(May 27,1986)indicate that most 

of the better laboratories tested can 

successfully analyze performance

evaluation within the proposed 

acceptance limits. EPA considered 

lowering the acceptance limits for the 

seven VOCs to 220percent (excluding

vinyl chloride). However, very few 

laboratories would be able to perform

within these limits for all seven of the 

TABU 3.-&HEDULE OF REPEATMON.ITORINGREOUIREMENTS 

the discretion to: system is out of compliance, public

notification of the system’s customersis 
a4 

.: 'I 25708 FederalRegister Vel. '-

VOCs.Only three outnf&ghtm~ . 

I laboratories wereable to aralyze six 

out of seven VOCB withii ihese limits in 

Water SupplyStudy %Y.Therefore. in 

the ha1de. the acce-ptancelevels are 

S O percent of -the true value �or 

concentrations ofo.010mgll orabove, 

, and Spercent of $he We value �or 

concentrations below~.oiOmg/l for 

seven VOCs Itrichloroethylene, carbon 

tetrachloride, 21.1-trichloroethane. 1,~­

dicbroethane, benzene. tidichloroefhylene, and p

dichlorobenzene). 

For vinyl chloride, the&al 

acceptance bits are based initially on 

rt40 percent of the hue value at all 

levels. This is3ecause the available 

data support acceptance limitsof A40 

percent and donotsupport acceptance

limits-of +apercent .�or&is compound.

EPA may modify fhe laboratory

performance requirementsfor all VOCs 

as new informationbecomes available. 

Even the best Jaboratories may not be 

able to analpe all he VOCs within the 

acceptancelimits 100percent of the 

time. Random errors are likely 40 occur 

in any.large datageneration activity.

P A has evaluated data from recent 

performanceevaiuation studies to 

determine how many analHes EPAand 

State laboratories were able to analyze

within the acceptance limits. The 

number of analytes within the 

acceptance limits varies from laboratory 

to 1aboratory.XPA evaluated data from 

Water Supply Study #l7 forEPA and 

State laboratories that analyzed for all 

eight VOCs. The data indicate that 35 

out of18laboratories (or 83percent of 

the laboratories] were able to analyze at 

least 8 out of 7 VOCs (excluding vinyl

chloride) af concentrations of 0.004 mg/l 

or above within-the acceptance hits, 

while only 7 of these laboratories (or 39 

percent ofthe laboratories) were able to 

analyze all 7 VOCs.For very low levels 

[<O.W mg/l) greater failure rates 

would result. Whenthe highest

concentration of pdichlorobenzene 

(0.776mg/l)was not considered, 15 I laboratories were still able to analyze at 

least 6 out of 7 VOCs within the 

acceptance limits, while the number of 

laboratories that were able to analyze

all 7 VOCs increased to 12(or87 percent

of the laboratories]. For vinyl chloride 

only 8 out of 18laboratories (or44 

percent of the laboratories) were able to 

analyze all three levels within the f40 

percent acceptance limits. When the 

lowest concentration (O.Ool5 =/I) was 

not considered, the number of 

laboratories within the acceptance

limits increased to 13out of 18[or 72 

percent of the laboratories). 

NO. 31981

= E =

S3FJAdsoevaluated.pretiminaxydata

from WatexSttpplyStudy i#;20to 

determinewhether thisshady supports

the results from the WaterSuppiyStudy

a7. Xkvosamples wereaffered in@

studyto hse-laboratories wishing20 

obtiiinconditiondappmvd for'voCa 

One sample oontainedfie @hfVocS 

for WMchMCLsareMiletinthis 

notice. The second sample.contirined4

of the 8 VOCs-plusstherSectiun1445

unregulatedVOCs.Excludinglvinyl

chloride, there were a total of 1% 

responses for the 7 VOCs from &e 

first sample and 9from the .second 

sample). Theteeults aresummarized in 

Table 4 fora total dsrl EPA andState 

11 outd 11,­

10 artd 11,. 

9 art of 11..---.......... I..---­ 8 art ol 11 82 

<a out of 11..-- 18 

Taking the data from the first sample

for the seven VOCs,36 out of 44 

laboratories {or 82 percentof the 

laboratories) were able to analyze at 

least 6out of 7 VOCswithin the 

acceptance limits, while only 22 out of 

44 (or 50 percent of the laboratories] 

were able to analyze all seven YOCs. 

Theseresults are similar to the results 

obtained in Water Supply Study #17 �or 

the 7 VOCs. 

Twenty-nine out of the 44laboratories 

(or 66 percent of the laboratories) were 

able to analyze vinyl chloride within the 

+40 percent limits. These results are 

similar to the results obtained in Water 

Supply Study #17 when the lowest 

concentration (0.0015 w/1)was not 

considered. 

Based on the results obtained in 

Water Supply Study #17 [which are 

supported by preliminary results from 

Water Supply Study #20), EPA 

concluded that it is reasonable to expect

that laboratories meet the acceptance

limits in 0 141.24(g)[11)for at least 6 out 

of 7 of the VOCs to receive conditional 

approval. Therefore, the Agency will 

provide conditional approval of VOC 

analysis to laboratories that meet the 

following requirements: 

(I) Use approved analytical methods 

as specified in 80 141.24(g)(10)and 

141,40(g); 

(2) Are approved for T�-IMsanalysis:

and 

laboratories. .- . 

1..Variances 

treatment techniques,-orother means 

which EPA finds are available (taking 

cost into consideration);.inthisnotice 

referred to collectively as .BAT. 

Furthermore;before a State may g

variance, it must find that the vari 

will not result in anunreasonable 

health, The level representing

unreasonable risk to health for each 

proposal addwssing the next 40 

contaminants required to be regulated

under the SDWA.byJune1988. The 

proposal is scheduled for the Fall of 

1987. In general, &e unreasonable risk 

to health level would reflect acute and 

subchronic.toxicity for shorter-term 

exposuresand high carcinogenicrisks 

(as calculated using the linearized mul 

stage model in accordance with the 

Agency's risk assessment guidelines]

long-term exposures. . . 

Under Section 1413(a)(4).States that 

choose to issue variances must..doSO 
removal of para-dichlorobenzene by $200per year to remove li2­

.. . -

CAssuming99 percent removal from 0.5 mg/l to 0.005 mgl11 

1 PTA- GAC 

Benze'ne....................................... "....-. 56,O00 1,ooO 180 13,000 5,500 153 

l,l,l-TCA ...........................................-... 50,OOO . 700 . 156 13,000 3,500 110 

p-BCB....................................... ......-......: 63,OW 1,300 . 204 13,000 1,700 72 

to 75,000 person (12 mgd) category.

Thus, aeration treatment offera 

significant economies of scale, e.g., with Both pilot- and full-scale data 

that packed tower aeration respect to 1,2-&&loroethane removal, and granular activated =*On are as plant size increases by a factor of 

ese three (0.1313 mgd to 0.037 mgd), the cost capab1e Of 90-99 percent Or Seater 

decreases by a factor of two (202 to removals of the VOCs [except that GAC 

gallons).,In addition, costs is not as effectiveas pTA for sol$/l,OOO chloride). In light of thisremoval 

or dichlorobenzene,carbon usage rates are vary the BAT standard for small 

based on projection of pilot column systems. 

data. Neither adequate adsorption Requin?d Examination and 

r isotherms nor coIumn data were Installation of Alternate Treatment 

available to project carbon usage rates Technologies.Under section 1415 of the 

Act, a State may grant variances from a 
25708 Federal Register J Vol. 52, No. 130 Wednesda 

NPDWR if certain conditions are met. that the State considers necessary. These conditions, described more fully These provisions are aimed at bringing below, include: (1)An inability to meet the system into Compliance with the 

the MCLs despite the installation of the MCL as soon as practicable. The 

best available technology; (21 a finding following points need to be taken into 

that the variance will not result in an consideration: -

unreasonable risk; (3) imposition of a (1)The schedule of compliance which 

complianceschedule; (4) implementation accompanies a variance mayrequire

of such additiond controlmeasures as that the system examine other treatment 

the State may require: and (5) public

notice of the proposed variance and 

opportunity for a hearing.

To receivea variance, a PWSwould 

be required to install BAT fmt even if 

the BAT was not anticipated to achieve 

the MCL; the objective would be to 

reduce the level of contaminants as 

much as could beachieved by those 

technologies. The only exception to this 

requirement is that if a system were to 

demonstrate that the best available 

technology only achieved de minimis 

reduction of the contaminant(s)of 

concern, the system would not have to 

install that technology.’However, as a 

condition of receiving a variance 

without installing MT, &e State could 

require comprehensive engineering

studies of other technologies and if any 

were technically feasible, it could 

require me of those technologies to be 

installed. 

EPA has identified three additional 

treatment methods that thestate may

require the PWS to investigate and,if 

feasible, to install as a conditionof 

obtaining a variance. These are:(I)

Removal using other aeration 

techniques, such as multiple tray

aeration, spray aeration, cascade 

aeration, diffused aeration, or mechnical 

aeration; (2) removal using powdered

activated carbon adsorption; and (3) use 

of an alternative source of water. 

EPA discouragessystems fromusing 

an alternativesource of water which 

has no VOC contaminationbut may be 

contaminated with other substances. 

Specifically, EPA discourages systems

which find low levels of VOCs in &eir 

ground water source, which is otherwise 

of good quality, from switchingto a 

surface water source where the risk 

from disinfectionby-products (e.g.,

trihalomethanes]might be greater than 

from the VOCs. In such a case, where 

alternative sources pose a greater risk 

than the VOCcontaminated supply. the 

water supplier should hat the original 

water. 

Subsections1415(a)(l](A)(i) and (ii) of 

the SDWA require the State.to prescribe 

a schedulefor compliance at the same 

time that it issues a variance. The 

schedule must include: (1)Incrementsof 

progress toward compliance: and (2) an 

implementation plan of such control 

measures and application of other 

treatment techniques or technologies 

methods (ea., various aeration 

technologies, powdered activated 

carbon, or alternate sources of water) to 

determine their availabiiity, ieasibility, 

costs. and effectiveness. 

12) Such an examination may include 

engineering studies and pilot projects,

for potentially applicable technologies, 

to determine what reduction in VOC 

levels could be achieved by the 

treatment method. EPA will Drovide 

guidance on examining tech;lologies for 

compliance schedules. 

(3) Systems or the State always .have 

the option of proposing studies of other 

methods. 

14) The State can decide whether any

of the possible teatment methodswould 

achievereductions in VOC levels 

justifying use of that particular method. 

In such cases, the State may require, as 

part of the complianceschedule,

installation and use of suchmethods by

the system.

Use ofPOLIDevices and3ottled 

Water.As described above, under 

section 1415(a](l)(A)(ii).the State is to 

prescribe a schedule for implementation

of any additional control measures it 

may require. The Statemay require the 

use of POU devices, bottled water, or 

other mitigating measures as an 

“additional control measure” during the 

period of a variance, as a conditionof 

receiving the variance, if an 

unreasonablerisk to health exists. 

In prescribing the use of POU devices,

the State would be required to impose

the same conditions as outlined in 

sectionllI.A.1 �or approval of POE 

devices. If a PWS distributes bottled 

water as a control measure. the PWS 

must ensure that the following

conditions are satisfied: 

(l)(a”JThe bottled water is subject to a 

monitoring program thatprovides

adequate assurances that the water 

meets all MCLs.The public water 

system must monitor the bottled water 

for VOCs the first quarter that it 

supplies water to the public. and 

annually thereafter. Results of the 

monitoring program shall be provided to 

the State annually, or 

(b) The public water system must 

receive a certification from the bottled 

water company that (i) the bottled water 

suppliedhas been taken from an 

“approved source” as defined in 21 CFR 

129.3(a): [ii) the bottled water company 

minimum standards for protection of 

public health. 

2. Exemptions 
Federal Register / Vol. 52,No. 130 / Wednesday, July 8, 1987 / Rules and Regulations 2570 ~~ ~~~~ ~~

a substantial number of instances, 

Public Notification 

persons served by it of (1)my violation 

of any MCL, treatment technique

requirement, or testing provision

prescribed by an NPDWR; (2) failure to 

comply with any monitoring requirement

under section 1445(a)of the Act; (3)

existence of a variance or exemption:

and (4) failure to comply with the 

requirementsof a schedule prescribed 

pursuant to a variance orexemption.

The 1986amendmentsrequire that, 

within 15months of enactment,EPA 

amend its current public notification 

regulations to provide for different types

and frequencies of notice based on the 

differences between violations which 

are intermittent or infrequent and 

violations which are continuousor 

frequent, taking into account the 

seriousness of any potential adverse 

health effects which may be involved. 

EPA proposed regulations to revise 

the public notification requirementson 

April 6,1987 (52 FR 10972).The 

regulations proposed that public notices 

for MCL and treatment technique

violations [“Tier 1violations”) contain 

mandatory health effects language

specifying concisely and in nontechnical terms what adverse health 

effects may occur as a result of the 

violation. States and water utilities 

would remain free to add additional 

information to each notice, as deemed 

appropriate for specific situations. The 

April 1987notice proposed specific

health effects language for the eight

VOCs which are subject to today’s

ruiemaking. The April 1987notice also 

proposed that a CWS with Tier 1 

violations must notify the public by 

newspaper, mail delivery of notice and 

press release (for acute violations) is 

required. The proposal states that public 

water systems which fail to comply with 

any monitoring or testing requirements,

which are granted variances or 

exemptions, or which fail to comply

with the requirementsof a variance or 

exemption schedule, would be required 

to give newspaper notice, with 

additional notice at State discretion. The 

PWS is allowed to post notice under 

certain conditions for Tier 1and Tier 2 

violations. The Agency expects to 

promulgate final public notification 

regulations in September1987. 

I. Reporting Requirements 

The current regulations, 40 CFR 

141.31, require public water systems to 

report monitoring data to States within 

specified time periods. EPA did not 

propose any changes in these 

requirementsfor the VOCs.No 

comments were received on this issue. 

Thus, EPA will require the same 

reporting requirementsfor the VOCsas 

required under the current regulations

for other contaminants. 

The reporting requirementsfor result 

of the monitoring for unregulated

contaminantsIdescribed below) apply 

to both the community water systems

(CWS)and the NTNCWS. Each CWS o 

NTNCWS must submit the results of th~ 

monitoring within thirty days ofreceipt

from the certified laboratory. These 

results are to be submitted to the State. 

In addition, the State or public water 

system must submit the following

information to EPA for every sample: (1 

Results of all the analytical methods, 

including negatives: (2) name and 

address of the system that supplied the 

sample: (3)contaminants for which the 

analyses were perform& (4) analytical

method(s) used (5) date of sample; and 

(6) date of analysis. 

J. Total Volatile Synthetic Organic

Chemicals(rvocl 

In the June12,IW,proposal for 

MCLGs for the VOCs, EPA requested

public comments on setting an MCLG 

and MCLfor total volatile organic

chemicals to provide additional 

protection from simultaneousexposure 

to multiple VOCs.following analysis oi 

public comments and available 

scientific information,EPA determined 

that an MCLG and MCL would not be 

appropriate at this time. This conclusior 

was discussed in the Nowember 1985 

notice. 

K.Monitorin..for Unregulated

Contaminants 

Section1445(a)[l) of the Act requires

EPA to promulgate regulations by

December 19.1987, which require public 

water systems to conduct a monitoring 

program for unregulated contaminants. 

Each system must monitor at least once 

every five years for unregulated

contaminantsunless �?PArequires more 

frequent monitoring. This data will 

assist EPA in determining whether 

regulations for these contaminants are 

necessary, and if so, what levels might

be appropriate. 

EPA proposed monitoring

requirements for 51unregulated

contaminants in the November 1985 

notice. The Agency also requested 

comment on a method developed for thc 

analysis of 1.2-dibromoethane (EDB)

and 12-dibrorno-3-chloropropane

(DBCP)at low levels. These two 

compounds are included among the 

substances that PWSs must monitor 

under Section1445,as discussed below. 

This method is entitled “Method 504­

1.2-Dibromoethane (EDB) and 12-

Dibromo-3-chloropropane in Water by

Microextraction and Gas 
Chromatography." EPA received no 

comments on Method 504. The Agency

believes that this method is adequate to 

determine concentrations of EDB and 

DBCP. Therefore, this method is 

included in this rule as the monitoring

method for these two contaminants. 

Several commenters pointed out that 

analysis of 10to 15other compounds on 

the list of 51 was more difficult than 

analysis of the other compounds,

resulting in higher costs. In addition, 

they observed that the likelihood of 

these substances being present is much 

less than for other VOCs. EPA agrees

with these comments and thus is 

promulgating monitoring regulations

which separate the unregulated

contaminants into three lists as follows: 

List 1:Monitoring required for all 

CWS and NTNCWSs. Compounds can 

be readily analyzed.

List 2:Monitoring required only for 

systems vulnerable to contamination by

these compounds. Compounds have 

limited localized occurrence potential

and require some specialized handling.

List 3: The State decides which 

systems would have to analyze for these 

Contaminants, which includes 

compounds that do not elute within 

reasonable retention time using packed

column methods or are difficult to 

analyze because of high volatility or 

instability, and are much less likely to 

be present in drinking water. 

EPA is deleting the monitoring

requirements for pentachloroethane and 

bis(z-chloroisopropy1) ether from the list 

of unregulated contaminants in the final 

rule. Pentachloroethane has been 

deleted because it is unstable in water. 

Bis(2-choroisopropyl) ether has been 

deleted because it does not purge well,

and there are very few occurrences in 

drinking water. Therefore, both of these 

are low priority compounds for 

regulation. EPA is adding

tetrachloroethylene to List 1because the 

rulemaking for this contaminant is now 

included with the contaminants 

scheduled for regulation in June 1988 . 

and the resulting monitoring data will be 

useful (see the November 13,1985.

notice for discussion of the 

tetrachloroethylene regulation). In 

addition, 1,3-dichloropropene has been 

added to List 1because it has been 

detected in ground waters and is 

measured by these analytical methods. 

Data gathered under this Section 1445 

regulation can be used for compliance 

purposes when EPA promulgates

regulations for tetrachloroethylene and 

any other of these VOCs for which EPA 

is developing MCLs. 

Table 6 presents the three lists of 

compounds. 

Table &Unregulated Contaminants - . 

List I: Monitoring RequiredforAll 

Systems 

Bromobenzene 

Bromodichloromethane 

Bromoform 

Bromomethane 

Chlorobenzene 

Chlorodibromomethane 

Chloroethane 

Chloroform 

Chloromethane 

o-Chlorotoluene 

p-Chlorotoluene

Dibromomethane 

m-Dichlorobenzene 

o-Dichlorobenzene 

trans-1,2-Dichloroethylene

cis-l,%Dichloroe thylene

Dichloromethane 

1,l-Dichloroethane

1,l-Dichloropropene

1,2-Dichloropropane

1.3-Dichloropropane

1,3-Dichloropropene

2,2-Dichloropropane

Ethylbenzene

Styrene

1,1,2-Trichloroethane 

1,1,1,2-Tetrachloroethane 

1,1,2,2-Tetrachloroe thane 

Tetrachloroethylene

1,2,3-Trichloropropane

Toluene 

p-Xylene

o-Xylene

m-Xylene 

List 2: Required for VulnerableSystems 

Ethylene dibromide (EDB)

1.2-Dibromo-3-Chlloropropane (DBCP) 

List 3:MonitoringRequired as the 

State's Discretion 

Bromochloromethane 

n-Butylbenzene

Dichlorodifluoromethane 

Fluorotrichlorome thane 

Hexachlorobutadiene 

Isopropylbenzene

p-Isopropyltoluene

Naphthalene

n-Propylbenzene

sec-Butylbenzene

tert-Butylbenzene

1,2,3-Trichlorobenzene

1,2,4-Trichlorobenzene

1,2.4-Trime thylbenzene

1.3.5-Trimethylbenzene

The compounds in List 1can be 

analyzed easily with the analytical

methods in this final rule [Methods

502.1, 503.1, and 524.1). As previously

discussed, the Agency has also 

developed capillary column methods 

[Methods 502.2 and 524.2) that are also 

available for the monitoring of these 

compounds. Monitoring for the 

concentrations usually increase 

disinfection by the consecutive 

The November 1985proposal

include repeat.monitoring for 

unregulated VOCs [unless imposed by.

the State); In this final ple, however, * 

EPA is requiring repeat monitoring for: 

unregulated contaminants every five 

years, as specified in the-SDWA 

Amendments of 1986,.However,EPh 

new list in five years. However, States 

are encouraged to require follow-up 

I 

, 
52, No. 130 1 Wednesday, July 8, 1987’ / Rules and Rendations 25711 

monitoring for unregulated

contaminants. The cornpositing

procedure is described in the section on 

Compliance Monitoring. 

IV.Effective Dates 

These regulations have an effective 

date ofjanuary 1,XX@:the laboratory

performance requirements and 

monitoring for compliance requirements (5 141.24(g)) and the unregulated

monitoring and reporting requirements (8 141.35 and 141.40)[Prior to the 

adoption of the compliance monitoring

requirements by the State, the authority

for compliance monitoring is section 

1445 of the Act]. All other provisions

promulgated in this final rulemaking

(concerning MCLs, variance, and 

exemptions, provisions of reporting and 

recordkeeping) are effective Jenuary 9, 

1989,as provided in section 1412(b)(10). 

V. Impact Analyses 

The economic impact analysis

supporting thisfinal rule is contained in 

“Economichpact Analysis of Proposed

Regulations to Control Volatile 

Synthetic Organic Chemicals in &inking

Water,” October 1985.as amended (Ref. 

3). The report presents estimates of the 

benefits end costs of regulatory

alternatives. Also included are analyses

required by the Regulatory Flexibility

Act and the Paperwork Reduction Act. 

The purpose of the assessment was to 

determine overall economic impacts o� 

the regulations. Theaddendum to the 

assessment responds to comments made 

during the public comment period. There 

has been no significant changein the 

initial assessment, which showed that 

approximately 1300 mmmunity water 

supplies would be expected to exceed 

the final standards without additional 

controls,If nearly all these systems took 

actions to comply with the regulations,

the total present value cost of 

compliance to the nation would be 

about $zsO million. On anannualized 

basis, the cost of compliance woutd be 

$21 million per year. Extending the VOC 

regulations to non-community nontransient water systems will require

approximately 400 additional systems io 

treat their water, at a capital cost of $XI 

million and approximately $1.5 million 

per year.

“be cost impacts on community water 

systems and consumera affected by

volatile organic contamination vary

depending upon tbe size of the PWS. 

Very small systems which serve from 25 

to 500people could be expected to 

increase their water rates by

approximately 54 cents per 1000gallons

of water. As a result of economies of ,

scale, large community systems serving 

more than 50,oOO people could be 

expected to increase their rates only

about 5 cents per 1OOOgallons.These 

increases would only affect systems

with contaminant levels above the 

standards. 

Under Executive Order 1m.EPA 

must judge whether a regulation is 

“major’’ and, therefore, subject to the 

requirements of a Repfatory Impact

Analysis. This action does not constitute 

a ”major” regulatory action because it 

will not have a major financial or 

adverse impact on the country.This 

regulation has been reviewed by the 

Officeof Management and Budget as 

required by Executive Order 122% and 

their comments are available in the 

public docket. 

The costs of compliance monitoring

and monitoring for the unregulated

contaminants are presented in Table 7 

(see Ref. 3). As noted above, composites

of up to five sources are allowed and the 

costs shown in Table 7 a6sume that 

systems composite a number of their 

sources. in addition, certain States 

conduct monitoring for small systems.

Cornpositing of different system sources 

by States is allowed in the regulations:

savings are estimated to be $500,~per 

year for the initial compliance

monitoring, $zOO,oOO per year for the 

initial unregulated monitoring, and 

$400.~per year for the repeat

compliance monitoring. 

TABLE7.-Cosrs ($ MUION/YEAR) 

FOR MON~TORJNG FOR COMPLIANCE 

WITH MCLS FOR vocs AND FOR 

UNREGULATED VOCs 

initial Round: 

VOG subject to MCLS.............. ”...-. $7.5 Unregulated COnta~tS.~ .........-.. $1.7 Repeat Monitoring: 

VOCs subject to MCLs_ ..........-........ $19.2 

Urnegofatedcontaminants........_...... 

1 The cost for repeat monitocing of umegu­ lated contaminants will vary because the 

Agency will specify a new list of contaminants 

to be monitored in ke years. Consequent1 , contaminants other than those specified L 

this notice may be listed at that time. 

The Regulatory Flexibility Act 

requires EPA to explicitly consider the 

effect of regulations on small entities. If 

there is a significant effect on a 

substantial number of small systems, the 

Agency must seek means to minimize 

the effects. With respect to the 

requirements of the Regulatory

Flexiblity Act, 5 U.S.C.802 et seg.,

today’s action will not have a significant

effect on a substantial number of small 

entities. Using the Small Business 

I 
2- Federal Register / Vol. 52, No. 130 / Wednesday, July 8,1987 / Rules and Regulations 

Administration’s deffinitions,a “small” 

water utility is one that serves fewer 

than 5O.OOO people. There are about 

78,500such systems. Of these, fewer 

than 1700are likely to have 

contamination levels greater than the 

Ma.Therefore, this rule will affect 

about that 2 percent of the “small” 

systems, which does not constitute a 

substantial number of small systems.

However, it is possible that today’s

action will have a substantial impactan 

a few small systems if regulated VOCs 

are found at levels higher than the MCLTherefore, the Agency has attempted to 

provide alternatives to the requirements

whenever possible. Specifically, EPA 

allows compositing of samples. Small 

systems may choose to composite their 

samples and to share the analytical 

costs. Also, the Agency has allowed 

bottled water and point-of-use devices 

as conditions of receiving a variance or 

exemption, even though decentralized 

treatment is less than the Agency’s longrange goal of centralized treatment (due 

to untreated taps and possible

inhalation effects), to accommodate the 

needs of the smaller systems with 

limited resources. The Agency also has 

given states the discretion to reduce 

monitoring frequency in accordance 

with a system’s findings of no VOCs and 

its vulnerability status. Consequently,

small systems which do not have VOC 

contamination in their water supply and 

are not located in a vufnerable areamay

have to monitor only infrequently. In 

addition, very small systems are not 

required to sample for unregulated

contaminant6 they are only required to 

provide a sample or make the 

opportunity for sampling available to 

the State. 

The information collection 

requirements in this rule have been 

submitted for approval to the Ofice of 

Management and Budget (OW) under 

the Paperwork Reducation Act, 44U.S.C. 

3501 et seq. The information collection 

requirements are not effective until 

OMB approves them and a technical 

amendment to that effect is published in 

the Federal Register. 

VI. References and Public Docket 

The following references are referred 

to in this notice and are included in the 

Public Docket together with other 

correspondence and information. The 

Public Docket is available for viewing

by appointment in Washington, D.C. by

calling the telephone number at the 

beginning of this notice. All public 

comments received on the proposal are 

included in the Docket. 

(1)* U.S.Environmental Protection 

Agency, Criteria and Standards 

Division, Analytical Methods/ 

Monitoring the VOCs in Drinking Water. 

June, 1987. 

(2) * U.S. Environmental Protection 

Agency, Criteria and Standards 

Division.Techologiesand Costs for the 

Removal of Volatile OrganicChemicals 

from Potable Water Supplies. May, 1985. 

(3)*U.S. Environmental Protection 

Agency, Officeof ProgramDevelopment

and Evaluation, Economic impact

Analysis of Proposed Regulations toControl Volatile Synthetic Organic

Chemicals in Drinking Water. October, 

1985,as amended 1987. 

(4) U.S. Environmental Protection 

Agency, Criteria and Standards 

Division, Summary of Comments and 

EPA Responses on-the ProposedMCLs 

for the VOCs,Reproposed MCLG for 

para-Dichlorobenzene,and 

“Requirements for Unregulated

Contaminants.” (June 1987) 

(5) Peters, W., and Clark, S.Memo: 

Risks Associated With Air Emissions 

from Aeration of Drinking Water. To 

Robert G. Kellam. Program Analysis and 

Technology Section and Arthur H. 

Perler, Science and Technology Branch, 

Criteria and Standards Division, Office 

of Drinking Water. Nov. 13,1985. 

(6)*National Toxicology Program.

Toxicology and Carcinogenesis Studies 

of 1,4-Dichlorobenzenein F344Rats and 

B6C3K Mice (Gavage Studies], final 

report, 1987(Technical Report Series No. 

319). 

(7j U.S.Environmental Protection 

Agency Ground Water Supply Survey

January 1983. 

(8)U.S. Environmental Protection 

Agency, Criteria and Standards 

Division. Criteria Document for orthoDichlorobenzene, metaDichlorobenzene, and parapDichlorobenzene. (June 1987) 

The starred (‘1 documents are avaUable for a fee from the National Technical Information 

Service, U.S.Department of Commerce. 5285 

Port Royal Road, Springfield, VA 22161.The 

toll-free number is 703/487-4650.These 

documents are also available for review at 

the Drinking WaterSupply Branch Office in 

WASRegional Offices. 

List of Subjects in 40CFR Parts141and 

142 

Chemicals, Reporting and recordkeeping requirements, Water supply,

Administrative practice and procedure. 

Dated June19,1987. 

Lee M.Thomas, 

Administmtor, EnvironmentalProtection 

Agency. 

Therefore, 40CFR Parts 141and 142 

are amended as follows: 

PART 141-CANlENDEDl 

1.In Part 141: 

a. The adlhority citation for Part 141 

continues to read as follows: 

Authority: 42 U.S.C. -1. SOOg-3,3OOj+ 

300g-8.and300j-8. ­

b. In 0 141.2, the existing paragraph

designations are removed, the existing

paragraphs are arranged in alphabetim

order, ahd the following new definition 

areadded: ­

s141.2. Definitions. * e t * * 

“Best available technology” or “BAT 

means the best technology, treatment 

techniques, or other means which the 

Admidstrator finds, after examination 

for efficacy under field conditions and 

not solely under laboratory conditions, 

are available (taking cost into 

consideration). For the purposes of 

setting MCLs for synthetic organic

chemicals, any BAT must be at least as 

effective as granular activated carbon. * * t * t . 

“Non-transient non-community watei 

system or “NTNCWS means a public 

water system that is not a community 

water system and that regularly serves 

at least 25 of the same persons over 6 , 

months per year. c t * * * 

“Point-of-entry treatment device” is 6 

treatment device applied to the drinkiq 

water entering a house or building for 

the purpose of reducing contaminants i~ 

the drinking water distributed 

throughout the house or building. 

“Pointsf-use treatment device” is a . 

treatment device applied to #isingle tap- used for the purpose of reducing

contaminants in drinking water at that 

one tap. C t t t . 

c. A new paragraph [g] is added to 

8 14124to read as foilows: 

0 141.24 Organic chemicals other than 

total trihalomethaner,samplingand ,.. ‘-. 

analyticalrequirements * t ,t . ”‘,’ - ’ - . . 

(g] Analysis ,of the +itaii;inints: iis? 

in 0 141.61(a) for purposes of. . . 

“i.

. determining compliance with the 

maxhyqcontaminant bveis shall be . conducted as followS: . 

(1)Ground-water systems’shall ..’. ;

sample at points of entry to the. . .:’ 

distribution system representative of .. 

each well. Sampling must be conducted.~ 

at the same location or a more :.i 

representative location each quaher. ’; 

Ground-water systems must sample .j 

every three months for each entry poib 

to the.distribution,system except as !:2 

provided in .paragraph (g](8)(i) of this .: 

section.