Permit Number:  03-A-1027-S2

Plant Number:  98-01-006

Company:  Trustile Doors of Iowa

Contact Person:
Responsible Party:
Todd Piper
Todd Piper
VP of Manufacturing Operations
VP of Manufacturing Operations

(720) 746-5410

<EMAIL_ADDRESS>

100 Enterprise Drive

Northwood, IA  50459

                              Permitted Equipment

Emission Point ID:  1

Emission Unit(s) and Control Equipment:

                                     EU ID
                                  Description
                            Maximum Rated Capacity
                     Control Equipment Description and ID
                                       1
Spray Booth 1
                                  4.7 Gal/hr
                              Dry Filters (CE 1)

Equipment Location:  100 Enterprise Drive
                        Northwood, IA  50459

Issuance of this permit shall not relieve the owner or operator of the responsibility to comply fully with applicable provisions of the State Implementation Plan (SIP), and any other requirements of local, state, and federal law.

                                Project Number
                              Project Description
                                 Stack Testing
                                 Issuance Date
                                    18-144
            Update VOC and HAP Limits, Update NESHAP Applicability
                                      No
                                    5/16/18

                                     Under the Direction of the Director of the
                                                Department of Natural Resources

                               PERMIT CONDITIONS

1.  Emission Limits

The owner or operator is required to report all emissions as required by law, regardless of whether a specific emission limit has been established in this permit.  The following emission limits shall not be exceeded:

                                   Pollutant
                                   lb/hr[1]
                                  tons/yr[2]
                                 Other Limits
                                Reference/Basis
Particulate Matter (PM)  -  State
                                      NA
                                      NA
                                  0.01 gr/scf
                               567 IAC 23.4(13)
Opacity
                                      NA
                                      NA
                                  40%[3], [4]
                            567 IAC 23.3(2)"d"
(Single HAP)
                                      NA
                                    9.0[5]
                                      NA
                                  Area Source
(Total HAP)
                                      NA
                                    24.0[5]
                                      NA
                                  Area Source

   [1] The emission limit is expressed as the average of three (3) runs.
   [2] The emission limit is based on a twelve (12) month rolling total.
   [3] The emission limit is based on a six (6) minute average.
   [4] An exceedance of the indicator opacity of `No Visible Emissions' will require the owner or operator to promptly investigate the emission unit and make corrections to operations or equipment associated with the exceedance.  If exceedances continue after the corrections, the Department may require additional proof to demonstrate compliance (e.g., stack testing).
   [5] Established in Project Number 18-144 in order for the facility to become an area source of HAP for the purposes of NESHAP. This limit applies to all non-combustion sources at this facility. The applicable compliance demonstration is specified in Condition 5.

2.  Compliance Demonstration(s)

                        Compliance Demonstration Table

                                   Pollutant
                            Compliance Methodology
                                   Frequency
                                 Test Run Time
                                  Test Method
PM  -  State
                             Material Tracking[1]
                               Rolling 12-Month
                                    1 hour
40 CFR 60, Appendix A, Method 5
40 CFR 51 Appendix M Method 202
Opacity
                                     None
                                      NA
                                    1 hour
40 CFR 60, Appendix A, Method 9
VOC
                             Material Tracking[1]
                               Rolling 12-Month
                                    1 hour
40 CFR 63, Appendix A, Method 320 or
40 CFR 60, Appendix A, Method 18
HAP
                             Material Tracking[2]
                               Rolling 12-Month
                                    1 hour
40 CFR 63, Appendix A, Method 320 or
40 CFR 60, Appendix A, Method 18

   [1] See Condition 5.A. of the permit for the required recordkeeping requirements.
   [2] See Condition 5.B. of the permit for the required recordkeeping requirements.

If an initial stack test is specified in the "Compliance Demonstration Table," the owner or the owner's authorized agent shall demonstrate compliance with the emission limitations contained in Condition 1 within the applicable time period specified below:

 Within sixty (60) days after achieving the maximum production rate and no later than one hundred eighty (180) days after the initial startup date of the proposed equipment for the addition of new equipment or the physical modification of existing equipment or control equipment.
 Within ninety (90) days of the issuance of this permit if there is no physical modification to any emission units or control equipment.

If any additional stack testing beyond an initial test (i.e. quarterly, semi-annual, annual, etc.) is required in "Compliance Demonstration Table," the owner or the owner's authorized agent shall demonstrate compliance with the emission limitations contained in Condition 1 as specified in the "Compliance Demonstration Table."  See Conditions 12.A.(4) and 12.B.(5) for notification and reporting requirements.

If stack testing is required, the owner or the owner's authorized agent shall use the test method and run time listed in the "Compliance Demonstration Table" unless another testing methodology is approved by the Department prior to testing.

2.  Compliance Demonstration(s) (Continued)
Each emissions compliance test must be approved by the Department.  Unless otherwise specified by the Department, each test shall consist of three (3) separate runs.  The arithmetic mean of three (3) acceptable test runs shall apply for compliance, unless otherwise indicated by the Department.

Per 567 IAC 25.1(7)"a", at the Department's request, a pretest meeting shall be held not later than fifteen (15) days before the owner or operator conducts the compliance demonstration.  A testing protocol shall be submitted to the Department no later than fifteen (15) days before the owner or operator conducts the compliance demonstration.  Representatives from the Department shall attend this meeting, along with the owner and the testing firm, if any.  It shall be the responsibility of the owner to coordinate and schedule the pretest meeting.  A representative of the Department shall be allowed to witness the test(s).  The Department shall reserve the right to impose additional, different, or more detailed testing requirements.

The owner shall be responsible for the installation and maintenance of test ports.  The unit(s) being sampled shall be operated in a normal manner at its maximum continuous output as rated by the equipment manufacturer, or the rate specified by the owner as the maximum production rate at which this unit(s) will be operated. In cases where compliance is to be demonstrated at less than the maximum continuous output as rated by the manufacturer, and it is the owner's intent to limit the capacity to that rating, the owner may submit evidence to the Department that this unit(s) has been physically altered so that capacity cannot be exceeded, or the Department may require additional testing, continuous monitoring, reports of operating levels, or any other information deemed necessary by the Department to determine whether this unit(s) is in compliance.

3.  Emission Point Characteristics

This emission point shall conform to the specifications listed below:
                                   Parameter
                                     Value
Stack Height (feet from the ground)
29.5
Discharge Style
Vertical, unobstructed
Stack Outlet Dimensions (inches)
34
Exhaust Temperature ([o]F)
Ambient
Exhaust Flowrate (scfm)
23,000

The temperature and flowrate are intended to be representative and characteristic of the design of the permitted emission point.  The Department recognizes that the temperature and flow rate may vary with changes in the process and ambient conditions.  If it is determined that any of the emission point characteristics above are different than the values stated, the owner or operator shall submit a request either by electronic mail or written correspondence to the Department within thirty (30) days of the discovery to determine if a permit amendment is required, or submit a permit application requesting to amend the permit.

4.  Federal Standards
 New Source Performance Standards (NSPS):
This emission unit is not subject to any NSPS subparts at this time as there are no applicable subparts for its source category.

NOTE:  The absence of the inclusion of any NSPS requirements as part of this permit does not relieve the owner or operator from any obligation to comply with all applicable NSPS conditions.

 National Emission Standards for Hazardous Air Pollutants (NESHAP):
This facility is of the source category for Subpart QQQQ (National Emission Standards for Hazardous Air Pollutants: Surface Coating of Wood Building Products; 40 CFR §63.4680  -  §63.4781).  However, this emission unit is not subject because the facility is an area source of HAP at this time. Subpart QQQQ is only applicable to major sources of HAP.

This facility is of the source category for Subpart HHHHHH (National Emission Standards for Hazardous Air Pollutants: Paint Stripping and Miscellaneous Surface Coating Operations at Area Sources; 40 CFR §63.11169  -  §63.11180). However, this emission unit is not subject because the facility does not apply any coating to any metal or plastic surface. Per 40 CFR §63.11170, the facility is not subject to the Subpart.

NOTE:  The absence of the inclusion of any NESHAP requirements as part of this permit does not relieve the owner or operator from any obligation to comply with all applicable NESHAP conditions.

5.  Operating Requirements with Associated Monitoring and Recordkeeping
Unless specified by a federal regulation, all records as required by this permit shall be kept on-site for a minimum of two (2) years and shall be available for inspection by the Department.  Records shall be legible and maintained in an orderly manner.  The operating requirements and associated recordkeeping for this permit shall be:
 Spray Booth 1 (EU 1), Spray Booth 2 (EU 2), Spray Booth 3 (EU 3), Spray Booth 4 (EU 4), and Spray Booth 5 (EU 5) shall not use more than 16,000 gallons of surface coating materials (stain, primer, sealer, solvent, etc) per rolling 12-month period. The VOC content of any surface coating material used in these spray booths (EU 1, 2, 3, 4, and 5) shall not exceed 10.0 pounds per gallon. The solids content of any surface coating material used in these spray booths (EU 1, 2, 3, 4, and 5) shall not exceed 27.7 pounds per gallon. The owner or operator shall:
 Retain the Safety Data Sheets (SDS) of any surface coating material used in these spray booths (EU 1, 2, 3, 4, and 5);
 On a monthly basis, record the total amount of surface coating materials, in gallons, used in these spray booths (EU 1, 2, 3, 4, and 5) during the previous month; and
 On a monthly basis, calculate and record the rolling 12-month total amount of surface coating materials, in gallons, used in these spray booths (EU 1, 2, 3, 4, and 5).
 The owner or operator shall not emit more than 9.0 tons of single HAP from all non-combustion sources at this facility per rolling 12-month period. The owner or operator shall not emit more than 24.0 tons of total HAP from all non-combustion sources at this facility per rolling 12-month period. The owner or operator shall maintain daily records of the total amount of surface coating materials, adhesives, and putties used in the spray booths (EU 1, 2, 3, 4, and 5), adhesive application process (EU 14), and putty application process (EU 15). For the purposes of calculating emissions, all HAP may be considered emitted on the day the materials are delivered to the facility or to the production line. On a monthly basis, the owner or operator shall:
 Record the total amount of surface coating materials, adhesives, and putties used in the spray booths (EU 1, 2, 3, 4, and 5), adhesive application process (EU 14), and putty application process (EU 15) during the previous month;
 Record the single HAP content of each surface material, adhesive, and putty used;
 Calculate and record the single HAP and total HAP emissions, in tons, from the spray booths (EU 1, 2, 3, 4, and 5), adhesive application process (EU 14), and putty application process (EU 15) during the previous month. Assume that 100% of the HAP content in each material is emitted;
 Calculate and record the single HAP and total HAP emissions, in tons, from any other non-combustion sources at this facility during the previous month; and
 Calculate and record the rolling 12-month single HAP and total HAP emissions, in tons, from the spray booths (EU 1, 2, 3, 4, and 5), adhesive application process (EU 14), putty application process (EU 15), and any other non-combustion emission sources at this facility.

            If the rolling 12-month total amount of single HAP emissions from all non-combustion sources, including the spray booths, adhesive application, and putty application, exceeds 7.2 tons, the owner or operator shall track single HAP emissions on a daily basis. On a daily basis, the owner or operator shall calculate the 365-day total amount of single HAP emissions from these emission units. This calculation must be done each day until the 365-day total amount of single HAP emissions from these emission units are less than 7.2 tons. Calculations may then be performed on a monthly basis as long as the total amount of single HAP emissions is below 7.2 tons.

            If the rolling 12-month total amount of total HAP emissions from all non-combustion sources, including the spray booths, adhesive application, and putty application, exceeds 19.2 tons, the owner or operator shall track total HAP emissions on a daily basis. On a daily basis, the owner or operator shall calculate the 365-day total amount of total HAP emissions from these emission units. This calculation must be done each day until the 365-day total amount of total HAP emissions from these emission units are less than 19.2 tons. Calculations may then be performed on a monthly basis as long as the total amount of total HAP emissions is below 19.2 tons.
 The owner or operator shall maintain the Dry Filters (CE 1) according to the facility's maintenance schedule. The owner or operator shall maintain a log of all maintenance and inspection activities performed on the Dry Filters (CE 1). This log shall include, but is not necessarily limited to:
 The date and time any inspection and/or maintenance was performed on the Dry Filters (CE 1);
 Any issues identified during the inspection and the date each issue was resolved;
 Any issues addressed during the maintenance activities and the date each issue was resolved; and
 Identification of the staff member performing the maintenance or inspection.

6.  Continuous Emission Monitoring Systems (CEMS)
Continuous emission monitoring is not required by this permit at this time.
7.  Department Review
This permit is issued under the authority of 567 Iowa Administrative Code (IAC) 22.3.  The proposed equipment has been evaluated for conformance with Iowa Code Chapter 455B; 567 IAC Chapters 20  -  35; and 40 Code of Federal Regulations (CFR) Parts 51, 52, 60, 61, and 63 and has the potential to comply.  This permit is issued based on information submitted by the applicant.  Any misinformation, false statements or misrepresentations by the applicant or by the applicant's representative(s) shall cause this permit to be void.
No review has been undertaken on the engineering aspects of the equipment or control equipment other than the potential of that equipment for reducing air contaminant emissions.  The Department assumes no liability, directly or indirectly, for any loss due to damage to persons or property caused by, resulting from, or arising out of the design, installation, maintenance or operation of the proposed equipment.

8.  Owner and Operator Responsibility
This permit is for the construction and operation of specific emission unit(s), control equipment, and emission point as described in this permit and in the application for this permit.  The permit holder, owner, and operator of the facility shall assure that the installation of the equipment listed in this permit conforms to the design in the application (i.e. type, maximum rated capacity, etc.).  No person shall construct, install, reconstruct or alter this emission unit(s), control equipment, or emission point without the required amended permit.

Any owner or operator of the specified emission unit(s), control equipment, or emission point, including any person who becomes an owner or operator subsequent to the date on which this permit is issued, is responsible for assuring that the installation, operation, and maintenance of the equipment listed in this permit is in compliance with the provisions of this permit and all other applicable requirements  and that adequate operation and maintenance is provided to ensure that no condition of air pollution is created.

9.  Transferability
Unless the equipment is portable, this permit is not transferable from one location to another or from one piece of equipment to another.  See Condition 12.A.(2) for notification requirements for relocating portable equipment (567 IAC 22.3(3)"f").

10.  Construction
 General Requirements:
      It is the owner's responsibility to ensure that construction conforms to the final plans and specifications as submitted.
      In permit amendments, all provisions of the original permit remain in full force and effect unless they are specifically changed by the permit amendment.  If a proposed project is not timely completed, the owner or operator shall seek a permit amendment in order to revert back to the most recent previous version of the permit.  The previous, unchanged permit provisions are included in the amendment for your convenience only and are unappealable.
      This permit or amendment shall become void if any one of the following conditions occurs:
 The construction or implementation of the proposed project, as it affects the emission point permitted herein, is not initiated within eighteen (18) months after the permit issuance date; or
 The construction or implementation of the proposed project, as it affects the emission point permitted herein, is not completed within thirty-six (36) months after the permit issuance date; or
 The construction or implementation of the proposed project, as it affects the emission point permitted herein, is not completed within a time period specified elsewhere in this permit.
 Changes to Plans and Specifications:
The owner or operator shall amend this permit or amendment prior to startup of the equipment if:
 Any changes are made to the final plans and specifications submitted for the proposed project; or
 This permit becomes void.
Changes to the final plans and specification shall include changes to plans and specifications for permitted equipment and control equipment and the specified operation thereof.
 Amended Permits:
The owner or operator may continue to act under the provisions of the previous permit for the affected emission unit(s) and emission point, together with any previous amendment to the permit, until one of the following conditions occurs:
          The proposed project authorized by this amendment is completed as it affects the emission unit(s) and emission point permitted herein; or
          This current amendment becomes void.

11.  Excess Emissions
Per 567 IAC 24.1(1), excess emissions during a period of startup, shutdown, or cleaning of control equipment are not a violation of the emission standard if it is accomplished expeditiously and in a manner consistent with good practice for minimizing emissions except when another regulation applicable to the unit or process provides otherwise.  Cleaning of control equipment, which does not require the shutdown of process equipment, shall be limited to one (1) six-minute period per one (1) hour period.
An incident of excess emissions other than the above is a violation and may be subject to criminal penalties according to Iowa Code 455B.146A.  If excess emissions are occurring, either the control equipment causing the excess shall be repaired in an expeditious manner, or the process generating the emissions shall be shutdown within a reasonable period of time, as specified in 567 IAC 24.1.
An incident of excess emissions shall be orally reported by telephone, electronic mail or in person to the appropriate field office within eight (8) hours of, or at the start of, the first working day following the onset of the incident [See Permit Condition 12.B.(1)]. A written report of an incident of excess emissions shall be submitted as a follow-up to all required initial reports within seven (7) days of the onset of the upset condition [See Permit Condition 12.B.(2)].

12.  Notification, Reporting, and Recordkeeping
 The owner or operator shall furnish the Department the following written notifications:
          Per 567 IAC 22.3(3)"b":
             The date construction, installation, or alteration is initiated postmarked within thirty (30) days following initiation of construction, installation, or alteration.
             The actual date of startup, postmarked within fifteen (15) days following the start of operation.
          Per 567 IAC 22.3(3)"f," when portable equipment for which a permit has been issued is to be transferred from one location to another, the Department shall be notified:
          At least fourteen (14) days before equipment relocation if the equipment will be located in a nonattainment area for the National Ambient Air Quality Standards (NAAQS) or a maintenance area for the NAAQS.
          At least seven (7) days before equipment relocation.
          Per 567 IAC 22.3(8), a new owner shall notify the Department of the transfer of equipment ownership within thirty (30) days of the occurrence.  The notification shall include the following information:
             The date of ownership change; the name, address, and telephone number of the responsible official, the contact person, and the owner of the equipment both before and after the ownership change; and the construction permit number(s) of the equipment changing ownership.
          Unless specified per a federal regulation, the owner or the owner's authorized agent shall notify the Department in writing not less than thirty (30) days before a required test or performance evaluation of a continuous emission monitor [567 IAC 25.1(7)].  The notification shall include:
             The time; the place; the name of the person who will conduct the tests; and other information as required by the Department.
         If the owner or operator does not provide timely notice to the Department, the Department shall not consider the test results or performance evaluation results to be a valid demonstration of compliance with the applicable rules or permit conditions.  Upon written request, the Department may allow a notification period of less than thirty (30) days.
 The owner or operator shall furnish the Department with the following reports:
 Per 567 IAC 24.1(2), an incident of excess emissions as defined in 567 IAC 20.2 shall be reported within eight (8) hours or at the start of the first working day following the onset of the incident.  The report may be made by electronic mail, in person or by telephone.
 Per 567 IAC 24.1(3), a written report of an incident of excess emissions as defined in 567 IAC 20.2 shall be submitted as a follow-up to all required initial reports to the Department within seven (7) days of the onset of the upset condition.
 Operation of this emission unit(s) or control equipment outside of those operating parameters specified in Permit Condition 5 in accordance to the schedule set forth in 567 IAC 24.1.
 Per 567 IAC 25.1(6), the owner or operator of any facility required to install a continuous monitoring system or systems shall provide quarterly reports to the Director, no later than thirty (30) calendar days following the end of the calendar quarter, on forms provided by the Director.
 Per 567 IAC 25.1(7), a written compliance demonstration report for each compliance testing event, whether successful or not, postmarked no later than six (6) weeks after the completion of the test period unless other regulations provide for other notification requirements.  In that case, the more stringent reporting requirement shall be met.

12.  Notification, Reporting, and Recordkeeping (Continued)

 All data, records, reports, documentation, construction plans, and calculations required under this permit shall be available at the plant during normal business hours for inspection and copying by federal, state, or local air pollution regulatory agencies and their authorized representatives, for a minimum of two (2) years from the date of recording unless otherwise required by another applicable law (i.e. NSPS, NESHAP, etc.)

 Information regarding this permit should be sent to the attention of the following individuals based on the type of information being submitted:  change in ownership (Air Quality Bureau Records Center), permit correspondence (Construction Permit Supervisor), stack testing correspondence (Stack Test Coordinator), and reports and notifications (Compliance Unit Supervisor and DNR Field Office).  The addresses are:

Air Quality Bureau
Iowa Department of Natural Resources
502 E. 9th St.
Des Moines, IA  50319
Telephone:<PHONE_NUMBER>
Fax:<PHONE_NUMBER>
DNR Field Office 2
2300 15[th] St. SW
Mason City, IA  50401
Telephone:<PHONE_NUMBER>
Fax:<PHONE_NUMBER>

13.  Appeal Rights

All conditions within an original permit may be appealed, subject to the appeal rights set forth in 561 IAC Chapter 7.  Amended conditions within a permit amendment may be appealed, subject to the appeal rights set forth in 561 IAC Chapter 7.  In permit amendments, all provisions of the original permit remain in full force and effect unless they are specifically changed by the permit amendment.  The previous, unchanged permit provisions are included in the amendment for your convenience only and are unappealable.

14.  Permit History

                                  Permit No.
                                  Project No.
                                  Description
                                     Date
                                 Stack Testing
                                   03-A-1027
                                    03-431
                                Original Permit
                                    9/8/03
                                      No
                                 03-A-1027-S1
                                    04-283
                   Changing Stack Discharge Characteristics
                                    5/27/04
                                      No

                                 END OF PERMIT


1 ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 141 [ FRL______________]

RIN Drinking Water Contaminant Candidate List 2; Notice AGENCY: Environmental Protection Agency.

ACTION: Notice.

SUMMARY: The Safe Drinking Water Act ( SDWA), as amended in 1996, requires the Environmental Protection Agency ( EPA) to publish a list of contaminants which, at the time of publication, are not subject to any proposed or promulgated national primary drinking water regulations, that are known or anticipated to occur in public water systems, and which may require regulations under SDWA ( section 1412 ( b)( 1)). SDWA, as amended, specifies that EPA must publish the first list of drinking water contaminants no later than 18 months after the date of enactment, i. e., by February 1998 ( henceforth referred to as the 1998 Contaminant Candidate List or the 1998 CCL), and every five years thereafter. Today's notice announces EPA's preliminary 2 decision to carry over the remaining 51 contaminants on the 1998 CCL as the draft CCL 2,

provides information on EPA's efforts to expand and strengthen the underlying CCL listing process to be used for future CCL listings, and requests comment on CCL related activities to improve the drinking water contaminant listing process. Today's draft CCL includes 42 chemicals or chemical groups and nine microbiological contaminants. The Agency's approach to the draft CCL 2 is to continue using the remaining contaminants on the 1998 CCL for prioritizing research and making regulatory determinations while working with the National Drinking Water Advisory Council ( NDWAC) and stakeholders to complete a review of the National Research Council ( NRC) recommendations for developing a more comprehensive and transparent CCL listing process. The EPA seeks comment on the range of CCL issues and activities addressed in this notice.

DATES: The Agency requests comment on today's notice. Comments must be received or postmarked by midnight [ INSERT DATE 60 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].

ADDRESSES: Comments may be submitted electronically, by mail, or through hand delivery/ courier. Follow the detailed instructions as provided in section I. C of the Supplementary Information section. The official public docket for this action is located at EPA West Building,

Room B102, 1301 Constitution Avenue, NW, Washington, DC.

FOR FURTHER INFORMATION CONTACT: For questions about this notice contact Dan 3 Olson at ( 202) 564 5239 or e mail olson. daniel@ epa. gov. For general information contact the EPA Safe Drinking Water Hotline at ( 800) 426 4791 or e mail: hotline sdwa@ epa. gov. The Safe Drinking Water Hotline is open Monday through Friday, excluding legal holidays, from 9: 00 a. m.

to 5: 30 p. m.

SUPPLEMENTARY INFORMATION I. General Information A. Does this Notice Impose Any Requirements on My Public Water System?

Neither this draft CCL 2 nor the final CCL 2, when published, imposes any requirements on anyone. Instead, it notifies interested parties of the availability of EPA's Draft CCL 2 and seeks comment on this draft list as well as EPA's efforts to improve the contaminant selection process for future CCLs. Contaminants on the list may become the subject of future regulations.

At that time, the public would be provided additional opportunities to comment as part of the rule making process.

B. How Can I Get Copies of Related Information?

1. Docket. EPA has established an official public docket for this action under Docket ID No.

OW 2003 0028. The official public docket is a collection of materials that is available for public 4 viewing at the Water Docket in the EPA Docket Center, ( EPA/ DC) EPA West, Room B102,

1301 Constitution Avenue, NW, Washington, DC. The EPA Docket Center Public Reading Room is open from 8: 30 a. m. to 4: 30 p. m., Monday through Friday, excluding legal holidays.

The telephone number for the Public Reading Room is ( 202) 566 1744, and the telephone number for the Water Docket is ( 202) 566 2426. For access to docket material, please call ( 202) 566

2426 to schedule an appointment.

2. Electronic access. You may access this Federal Register document electronically through the EPA Internet under the Federal Register listings at http:// www. epa. gov/ fedrgstr/.

An electronic version of the public docket is available through EPA's electronic public docket and comment system, EPA Dockets. You may use EPA Dockets at http:// www. epa. gov/ edocket/ to submit or view public comments, access the index listing of the contents of the official public docket, and to access those documents in the public docket that are available electronically. Once in the system, select " search," then key in the appropriate docket identification number.

Certain types of information will not be placed in the EPA Dockets. Information claimed as confidential business information ( CBI) and other information whose disclosure is restricted by statute, which is not included in the official public docket, will not be available for public viewing in EPA's electronic public docket. EPA's policy is that copyrighted material will not be placed in EPA's electronic public docket but will be available only in printed, paper form in the official public docket. Although not all docket materials may be available electronically, you may still access any of the publicly available docket materials through the docket facility identified in 5 section I. B. 1.

For public commenters, it is important to note that EPA's policy is that public comments,

whether submitted electronically or in paper, will be made available for public viewing in EPA's electronic public docket as EPA receives them and without change, unless the comment contains copyrighted material, CBI, or other information whose disclosure is restricted by statute. When EPA identifies a comment containing copyrighted material, EPA will provide a reference to that material in the version of the comment that is placed in EPA's electronic public docket. The entire printed comment, including the copyrighted material, will be available in the public docket.

Public comments submitted on computer disks that are mailed or delivered to the docket will be transferred to EPA's electronic public docket. Public comments that are mailed or delivered to the Docket will be scanned and placed in EPA's electronic public docket. Where practical, physical objects will be photographed, and the photograph will be placed in EPA's electronic public docket along with a brief description written by the docket staff.

C. How and to Whom Do I Submit Comments?

You may submit comments electronically, by mail, or through hand delivery/ courier. To ensure proper receipt by EPA, identify the appropriate docket identification number in the subject line on the first page of your comment. Please ensure that your comments are submitted within the specified comment period. Comments received after the close of the comment period will be marked " late." The EPA is not required to consider these late comments. 6 1. Electronically. If you submit an electronic comment as prescribed below, EPA recommends that you include your name, mailing address, and an e mail address or other contact information in the body of your comment. Also include this contact information on the outside of any disk or CD ROM you submit, and in any cover letter accompanying the disk or CD ROM. This ensures that you can be identified as the submitter of the comment and allows EPA to contact you in case EPA cannot read your comment due to technical difficulties or needs further information on the substance of your comment. EPA's policy is that EPA will not edit your comment, and any identifying or contact information provided in the body of a comment will be included as part of the comment that is placed in the official public docket, and made available in EPA's electronic public docket. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment.

a. EPA Dockets. Your use of EPA's electronic public docket to submit comments to EPA electronically is EPA's preferred method for receiving comments. Go directly to EPA Dockets at http:// www. epa. gov/ edocket, and follow the online instructions for submitting comments. Once in the system, select " search," and then key in Docket ID No. OW 2003 0028.

The system is an " anonymous access" system, which means EPA will not know your identity,

e mail address, or other contact information unless you provide it in the body of your comment.

b. E mail. Comments may be sent by electronic mail ( e mail) to OW Docket@ epa. gov,

Attention Docket ID No. OW 2003 0028. In contrast to EPA's electronic public docket, EPA's e mail system is not an " anonymous access" system. If you send an e mail comment directly to the Docket without going through EPA's electronic public docket, EPA's e mail system automatically captures your e mail address. E mail addresses that are automatically captured by 7 EPA's e mail system are included as part of the comment that is placed in the official public docket, and made available in EPA's electronic public docket.

c. Disk or CD ROM. You may submit comments on a disk or CD ROM that you mail to the mailing address identified in section I. C. 2. These electronic submissions will be accepted in WordPerfect or ASCII file format. Avoid the use of special characters and any form of encryption.

2. By mail. Send an original and three copies of your comments to: Water Docket,

Environmental Protection Agency, Mail Code: 4101T, 1200 Pennsylvania Ave., NW,

Washington, DC, 20460, Attention Docket ID number OW 2003 0028.

3. By hand delivery or courier. Deliver your comments to: Water Docket, Environmental Protection Agency, EPA West Building, Room B102, 1301 Constitution Avenue, NW,

Washington, DC, Attention Docket ID number OW 2003 0028. Such deliveries are only accepted during the Docket's normal hours of operation as identified in section I. B. 1.

D. What Should I Consider as I Prepare My Comments for EPA?

You may find the following suggestions helpful for preparing your comments:

1. Explain your views as clearly as possible.

2. Describe any assumptions that you used.

3. Provide any technical information and/ or data you used that support your views. 8 4. If you estimate potential burden or costs, explain how you arrived at your estimate.

5. Provide specific examples to illustrate your concerns.

6. Offer alternatives.

7. Make sure to submit your comments by the comment period deadline identified.

8. To ensure proper receipt by EPA, identify the appropriate docket identification number in the subject line on the first page of your response. It would also be helpful if you provided the name, date, and Federal Register citation related to your comments.

II. Background and Summary of Today's Notice This section summarizes the purpose of today's notice and provides a brief background on the CCL requirements and prior activities related to the CCL.

A. What is the Purpose of Today's Action?

The drinking water CCL is the primary source of priority contaminants for evaluation by EPA's drinking water program. Contaminants on the CCL are currently not subject to any proposed or promulgated national primary drinking water regulation, but are known or anticipated to occur in public water systems, and may require regulation under SDWA. The EPA conducts research on health, analytical methods, treatment technologies and effectiveness, and contaminant occurrence for priority drinking water contaminants on the CCL. The Agency also develops drinking water guidance and health advisories, and makes regulatory determinations for 9 priority contaminants on the CCL.

Today's Federal Register notice explains why EPA is carrying over the remaining 51 contaminants on the1998 CCL as the draft CCL 2 and provides background information on the list. Additionally, this notice describes efforts to improve on the CCL selection process, the NRC recommendations to EPA on developing future CCLs, and related issues being evaluated by EPA and NDWAC to implement the NRC recommendations. ( The NDWAC provides independent advice, consultations, and recommendations to EPA on matters related to the activities, function,

and policies of the Agency under the SDWA, as amended. See section V for further discussion on NDWAC.) The EPA requests comment on the draft CCL 2 and on the process for developing future CCLs.

B. The Background of the CCL.

The SDWA is the core statute addressing drinking water at the Federal level. Under SDWA, EPA sets public health goals and enforceable standards for drinking water quality. In 1996, Congress amended SDWA to emphasize sound science and risk based priority setting.

Congress also changed the way drinking water regulatory priorities are set by establishing the CCL requirements. The 1996 SDWA amendments require EPA to ( 1) publish every five years a list of currently unregulated contaminants in drinking water that may pose risks, and ( 2) make determinations on whether or not to regulate at least five contaminants on a five year cycle, or three and a half years after each CCL ( SDWA § 1412 ( b)( 1)).

Following the 1996 SDWA Amendments, EPA sought NDWAC's recommendations on 10 the process that should be used to identify contaminants for inclusion on the CCL. For chemical contaminants, the Agency developed screening and evaluation criteria based on recommendations from NDWAC and identified 262 potential chemical contaminants. For microbiological contaminants, NDWAC recommended that the Agency seek external expertise to identify and select potential waterborne pathogens. As a result, the Agency convened a workshop of microbiologists and public health experts, developed screening and evaluation criteria based on workshop recommendations, and evaluated an initial list of 25 potential microbiological contaminants.

The 1998 CCL process benefitted from considerable input from the scientific community and the public through stakeholder meetings and the public comments received on the draft CCL published in 1997. The EPA published the final CCL containing 50 chemical and 10 microbiological contaminants in March of 1998 ( 63 FR 10273). A detailed discussion of how EPA developed the 1998 CCL is presented in section III of this notice.

After publication of the final 1998 CCL, EPA began collecting occurrence data and conducting research on the CCL contaminants. Data collection efforts include assessing the occurrence of contaminants in public water systems through the Unregulated Contaminant Monitoring Regulation ( 64 FR 50556), as well as evaluating occurrence data from national surveys and considering State level contaminant occurrence information. Research efforts focused on obtaining the information needed to characterize the adverse health effects of contaminants, drinking water treatment options, and the development of analytical methods to detect contaminants in drinking water.

As noted above, the 1996 SDWA also directs EPA to select at least five contaminants 11 from the CCL every five years to determine if regulating the contaminants with a national primary drinking water regulation would present a meaningful opportunity for health risk reduction ( SDWA § 1412 ( b)( 1)). In order to make regulatory determinations on contaminants, EPA must have sufficient data to evaluate when and where contaminants occur, human exposure, and the risk to public health.

On July 18, 2003, EPA announced its final determinations for a subset of contaminants on the 1998 CCL ( 68 FR 42898), which concluded that sufficient data and information were available to make the determination that a regulation was not appropriate for the following nine contaminants: Acanthamoeba, aldrin, dieldrin, hexachlorobutadiene, manganese, metribuzin,

naphthalene, sodium, and sulfate.

III. Developing Today's Draft Drinking Water Contaminant Candidate List This section provides the approach EPA used to develop the draft CCL 2, explains the rationale to support the approach, and presents the draft CCL2.

A. Approach and Rationale for the Draft CCL 2.

The EPA's approach for the draft CCL 2 is to continue to use contaminants identified on the 1998 CCL to set drinking water research priorities and make regulatory determinations. The EPA believes that it is appropriate for the draft CCL 2 to be based on the 1998 CCL because ( 1)

in developing the 1998 CCL, the Agency used peer reviewed data and information to evaluate 12 contaminants; ( 2) EPA relied on significant input from experts and stakeholders to develop a high quality process for selecting the contaminants on the CCL; ( 3) the Agency has invested in research and data collection activities related to the CCL, and is preparing to make regulatory determinations in the 2006 time frame using the data collected from these activities; and ( 4)

continued reliance on high priority contaminants remaining from the 1998 CCL allows the Agency to focus resources on completing ongoing work on an expanded process for classifying drinking water contaminants based on recent recommendations of the National Research Council ( NRC,

2001). A more detailed discussion of this approach follows.

1. Organizing and extracting data.

a. Evaluating available chemical contaminant listings. The EPA reviewed contaminants from eight well known lists, as well as contaminants recommended by stakeholders, to develop the 1998 CCL ( Table II 1). These lists contained chemicals that could be of potential concern in drinking water. In addition, EPA evaluated a number of other contaminants identified by stakeholders during the December 2 3, 1996, stakeholder meeting for potential inclusion on the CCL. In the process of creating the final list, EPA removed from consideration 23 contaminants suspected of being endocrine disruptors and 35 pesticides, because both groups of chemicals were the focus of additional data collection efforts under other programs in the Agency. The EPA intends to consider both groups of chemicals as part of the next CCL screening and evaluation process. 13 Table II 1. Initial Chemical Lists Considered for Development of the 1998 CCL.

List Description 1991 Drinking water priority list ( DWPL, EPA, 1991) 56 contaminants Health advisories ( HAs) 108 contaminants, ( included all contaminants with HAs or HAs under development)

EPA's Integrated Risk Information System database 48 contaminants, based on a risk based screen developed by EPA for the 1994 DWPL Contaminants identified by public water systems 22 " non target" contaminants identified by public water systems for the 1994 DWPL Agency for Toxic Substances and Disease Registry's list of contaminants found at Comprehensive Environmental Response, Compensation and Liability Act sites Top 50 contaminants from the 1995 list of 275 prioritized hazardous substances Stakeholder summary list 59 contaminants proposed as candidates by participants in a December 2 3, 1997 stakeholder meeting Toxic Release Inventory ( TRI) list 51 contaminants that met the criteria for assessing the potential to occur in public water; derived from an original 1994 TRI list of 343 chemicals b. Screening chemical contaminants. In 1997, EPA developed screening criteria to evaluate the potential occurrence and health effects of chemical contaminants gathered from the lists based on the recommendation of experts in the drinking water field, including NDWAC.

These screening criteria focused on the following two questions:

1. Is a given contaminant found in water at levels of health concern?

2. If no data exists on contaminant occurrence, is the contaminant likely to be found in water based on surrogates for occurrence? 14 An affirmative answer to either question moved the contaminant to the health effects phase of the evaluation. Contaminants met the criteria if the available data indicated occurrence in a drinking water system serving a population of 100,000 or more, occurrence in two or more States, or occurrence in 10 or more small public water systems at levels that would trigger concern for human health. If a contaminant did not have specific occurrence data, EPA assessed the potential for a contaminant to occur in drinking water based on surrogates for occurrence.

Surrogates for occurrence included: TRI release estimates, production amounts from industry data, and physical chemical properties. A contaminant was considered to have the potential to occur if, using the TRI, the release to surface water was in excess of 400,000 pounds per year and the physical chemical properties indicated persistence and mobility of the contaminant. A contaminant was also considered to have the potential to occur if the production volume exceeded 10 billion pounds per year, and physical chemical properties indicated persistence and mobility of the contaminant.

If a pollutant met the occurrence screening criteria, EPA then screened it for potential health effects. The health effects phase of the evaluation had one major criterion: was there evidence, or was there suggestion, that the contaminant causes adverse human health effects?

This criterion was met if a contaminant had one or more of the following elements: ( 1) listed by California Proposition 65, ( 2) addressed by an EPA Health Advisory, ( 3) considered a likely ( based on animal data) or known ( based on human data) carcinogen by EPA or the International Agency for Research on Cancer, ( 4) evaluated by more than one human epidemiological study ( indicating adverse effects), ( 5) received an oral value in EPA's Integrated Risk Information System, ( 6) regulated in drinking water by another industrial country, ( 7) identified as a member 15 of a chemical family of known toxicity, or ( 8) characterized by a structural activity relationship indicating toxicity. If a contaminant had none of these elements, then EPA did not include it in the 1998 CCL.

A contaminant that met both the occurrence screening criteria and received an affirmative response to any of the above health effects screening elements resulted in that contaminant's inclusion into the draft 1998 CCL.

c. Selecting microbiological contaminants. In May of 1997, at the recommendation of NDWAC, EPA convened a workshop on microbiology and public health to develop a list of pathogens for possible inclusion in the 1998 CCL ( 62 FR 52193). Participants included experts from academia, the drinking water industry, EPA, and other Federal agencies. The EPA prepared and distributed a list of 25 microorganisms ( 6 protozoa, 8 viruses, 7 bacteria, and 4 algal toxins)

for initial consideration by workshop members. Microorganisms were included on this initial list if they were identified in disease outbreak data, if published literature documented the occurrence of known or suspected pathogens in water, or if other information suggested the possibility of a public health risk. The workshop participants established screening criteria for deciding whether an organism should appear on the CCL. These criteria were ( 1) public health significance, ( 2)

known waterborne transmission, ( 3) occurrence in source water, ( 4) effectiveness of current water treatment, and ( 5) adequacy of analytical methods.

All of the microorganisms included on the initial EPA list, as well as other organisms that arose during the discussions, were evaluated against these criteria. The results of the deliberations of the microbiology workshop were adopted by NDWAC and subsequently utilized by the Agency to select 13 microbiological contaminants placed on the draft 1998 CCL. 16 2. Input from stakeholders, experts, and the public.

The EPA relied on significant input from experts and stakeholders to develop a high quality process for selecting the contaminants on the 1998 CCL. The Agency sought stakeholder input from a number of sources and at several different junctures in the CCL development process. First, EPA convened a day long meeting of over 50 experts, including representatives from industry, academia, consultants, and other government agencies to review a draft of the strategy for developing the CCL. The EPA also convened NDWAC to review the strategy and make recommendations on the development of the CCL. Experts on the NDWAC met numerous times to discuss the CCL process and data on potential contaminants.

As mentioned in the prior section, EPA also relied on the advice of nationally recognized experts in the field of microbiology, during a separate meeting, to classify microbiological contaminants. These experts identified and selected the microbiological contaminants for initial consideration.

Additionally, EPA consulted with the Agency's Science Advisory Board which is a public advisory group that provides extramural scientific information and advice to EPA.

The draft CCL containing 58 chemical and 13 microbiological contaminants was published on October 6, 1997 ( 62 FR 52193). The EPA requested comment on the approach used to develop the CCL, and on whether specific contaminants should be on the list. The EPA received 71 comments from many segments of the drinking water community including trade associations,

environmental groups, industries, chemical manufacturers, State and local health regulatory agencies, water utilities, and private citizens. Commenters provided data and information on 17 specific contaminants and included suggestions on the process for future CCL development.

Based on these comments, EPA removed 10 chemical and 4 microbiological contaminants, and added 2 chemical and 1 microbiological contaminant to the final list. The final 1998 CCL contained 50 chemical and 10 microbiological contaminants and was published on March 2, 1998 ( 63 FR 10273).

3. Research and data collection for contaminants on the 1998 CCL.

The EPA has made data collection and research on the CCL contaminants a priority and continues to collect information and conduct research in the areas of health effects, analytical methods, treatment, and occurrence. As noted previously, the Agency is preparing to make regulatory determinations in the 2006 time frame using the data collected from these activities.

a. Research on health effects, treatment, and analytical methods. The Drinking Water Research Program's Multi Year Plan identifies over 50 projects for contaminants on the CCL.

These projects are scheduled for completion in the next two years and span three research areas:

health effects, treatment, and analytical methods. The results of these activities will provide the information needed to characterize potential health impacts, assess the ability to detect selected contaminants in drinking water, and verify treatment capability and cost.

b. Data collection on occurrence. To assess whether the CCL contaminants are occurring in drinking water systems, EPA identified occurrence priorities and determined whether analytical methods were available to monitor for priority CCL contaminants. Because SDWA requires EPA to limit monitoring requirements to 30 contaminants in any 5 year cycle, only a 18 subset of the CCL contaminants were monitored in the first round of data collection. Data will be available for use from the first five year cycle of monitoring in mid 2004. The second cycle of data collection is expected to begin in 2006 and will be completed in mid 2010, after EPA proposes and promulgates a new list of contaminants for monitoring. Research is also underway to develop methods for contaminants currently without adequate analytical methods, or where the current analytical method detection limit was above the known adverse health effect level of concentration. Completion of these methods will allow EPA to make regulatory determinations in the future.

Because data from ongoing research and data collection activities will become available in the next few years, EPA believes that it is appropriate to maintain current focus on gathering this information in preparation for making regulatory determinations in 2006.

4. Development of an improved classification process for future CCLs.

Continued focus on many of the priority contaminants from the 1998 CCL allows the Agency to target resources to complete its ongoing work on an expanded process for classifying drinking water contaminants, so that contaminants identified in many more sources can be effectively screened.

After the 1998 CCL was published, the Agency asked the National Research Council, the operating arm of the National Academy of Sciences, to review the 1998 CCL selection process and provide recommendations on how the process could be improved. These recommendations were developed over several years and provided to the Agency in late 2001 ( see section IV). On 19 balance, the NRC found the 1998 CCL to be an important first step and noteworthy effort to identify and select unregulated chemical and microbiological drinking water contaminants. As with any new initiative, the NRC identified a number of opportunities to strengthen and expand the analytical process upon which the 1998 CCL was based. The NRC recommendations focused on developing a larger initial list ( universe) and on identifying new approaches for screening larger numbers of potential CCL contaminants. While the NRC recommendations greatly expand the universe of contaminants and suggest a change in the manner in which contaminants are selected for the CCL, they are based on the same fundamental principles used in developing the 1998 CCL  a focus on health impacts and occurrence. The NRC approach addresses the expansion of the universe of contaminants and recommends a process that combines expert judgement with the use of computerized data sources and classification processes to screen contaminants ( see section IV. C for more information). The use of automated classification processes would allow EPA to evaluate many more contaminants than experts alone can evaluate in the absence of these processes. The much broader and more complex approach recommended by the NRC may enable EPA to gather information from sources that were not used to develop the 1998 CCL, and thus strengthen the Agency's ability to identify emerging contaminants.

The EPA agrees that an approach that combines expert judgement with automated classification processes should be explored. The Agency is continuing to assess and refine the approach recommended by the NRC. The Agency believes that the CCL proposed today is sound, and should continue to be the source of contaminants for making additional regulatory determinations in the near term. This, however, should not be interpreted to mean that EPA is restricted to the contaminants on this CCL for making regulatory determinations. The EPA may 20 add contaminants to this list and make regulatory determinations for any unregulated contaminant not on today's CCL, as necessary, to address an urgent threat to public health.

B. The Draft CCL 2.

Table II 2 lists the contaminants on the draft CCL 2. These contaminants are identified by name and, where available, the Chemical Abstracts Service Registry Number ( CASRN). The draft CCL 2 consists of nine microbiological contaminants and 42 chemical contaminants or contaminant groups.

Table II 2. Draft Drinking Water CCL 2.

Microbiological Contaminant Candidates Adenoviruses Aeromonas hydrophila Caliciviruses Coxsackieviruses Cyanobacteria ( blue green algae), other freshwater algae, and their toxins Echoviruses Helicobacter pylori Microsporidia ( Enterocytozoon and Septata)

Mycobacterium avium intracellulare ( MAC)

Chemical Contaminant Candidates CASRN 1,1,2,2 tetrachloroethane 79 34 5 1,2,4 trimethylbenzene 95 63 6 1,1 dichloroethane 75 34 3 1,1 dichloropropene 563 58 6 Chemical Contaminant Candidates CASRN 21 1,2 diphenylhydrazine 122 66 7 1,3 dichloropropane 142 28 9 1,3 dichloropropene 542 75 6 2,4,6 trichlorophenol 88 06 2 2,2 dichloropropane 594 20 7 2,4 dichlorophenol 120 83 2 2,4 dinitrophenol 51 28 5 2,4 dinitrotoluene 121 14 2 2,6 dinitrotoluene 606 20 2 2 methyl Phenol ( o cresol) 95 48 7 Acetochlor 34256 82 1 Alachlor ESA & other acetanilide pesticide degradation products N/ A Aluminum 7429 90 5 Boron 7440 42 8 Bromobenzene 108 86 1 DCPA mono acid degradate 887 54 7 DCPA di acid degradate 2136 79 0 DDE 72 55 9 Diazinon 333 41 5 Disulfoton 298 04 4 Diuron 330 54 1 EPTC ( s ethyl dipropylthiocarbamate) 759 94 4 Fonofos 944 22 9 p Isopropyltoluene ( p cymene) 99 87 6 Linuron 330 55 2 Chemical Contaminant Candidates CASRN 22 Methyl bromide 74 83 9 Methyl t butyl ether ( MTBE) 1634 04 4 Metolachlor 51218 45 2 Molinate 2212 67 1 Nitrobenzene 98 95 3 Organotins N/ A Perchlorate 14797 73 0 Prometon 1610 18 0 RDX 121 82 4 Terbacil 5902 51 2 Terbufos 13071 79 9 Triazines and degradation products of triazines including, but not limited to Cyanazine 21725 46 2 and atrazine desethyl 6190 65 4 Vanadium 7440 62 2 IV. The National Research Council's Recommended Approach for Developing Future CCLs This section summarizes the NRC recommendations to EPA for developing future CCLs and discusses other issues related to contaminant selection and prioritization.

The EPA sought the advice of the NRC in response to comments received during the development of the 1998 CCL, which indicated a need for a broader, more systematic approach for selecting contaminants.

The Agency asked the NRC to address three key topics related to drinking water 23 contaminant selection and prioritization:

1. What approach should be used to develop future CCLs?

2. How best should EPA assess emerging drinking water contaminants and related databases to support future CCL efforts?

3. What approach should EPA use to set priorities for contaminants on the CCL?

The NRC's findings and recommendations on these topics were published in the following three NRC reports: Setting Priorities for Drinking Water Contaminants ( NRC, 1999a),

Identifying Future Drinking Water Contaminants ( NRC, 1999b), and Classifying Drinking Water Contaminants for Regulatory Consideration ( NRC, 2001). The discussion in today's notice focuses on the 2001 report, which synthesizes key findings from the prior reports.

In its report entitled Classifying Drinking Water Contaminants for Regulatory Consideration, the NRC recommended that EPA use a two step process for generating future CCLs. The first step in the process is to select contaminants from a broad universe of chemical,

microbiological, and other types of potential drinking water contaminants for inclusion on a preliminary CCL ( PCCL), based on a screening assessment of human health impacts, occurrence data, and expert judgement ( NRC, 2001). The second step in the process is to use a classification algorithm ( a formula or set of steps for solving a particular problem), in conjunction with expert judgement, to select from the PCCL contaminants to be included on the CCL. The NRC believes that this process of selecting contaminants for future CCLs will result in a more systematic,

transparent, and comprehensive approach to classifying drinking water contaminants.

A. Screening the Universe of Contaminants. 24 The NRC suggests that the universe of potential drinking water contaminants could contain tens of thousands contaminants and recommends that EPA consider a range of contaminants including naturally occurring substances, emerging waterborne pathogens, chemical agents, byproducts, degradates of chemical agents, radionuclides, and biological toxins as part of the universe. The NRC's approach to assembling the universe is to begin with data sources that are currently available and to work with the public, the drinking water industry, and the scientific community to develop a strategy for assessing contaminants that are not found in existing databases or lists ( NRC, 2001). This approach could greatly expand on the number of contaminants to be reviewed and the number of databases and lists to be searched.

B. Compiling the PCCL.

The NRC further suggested that EPA develop a well conceived set of screening criteria that can be applied rapidly and routinely, in conjunction with expert judgement, to screen the universe of potential drinking water contaminants to a much smaller PCCL.

To compile the PCCL, the NRC recommends an approach that relies on health effects and occurrence information. The NRC suggests a screening process that selects contaminants from a hierarchy of information based on the following criteria related to both health effects and occurrence:

1. Contaminants that are demonstrated to cause adverse health effects and are demonstrated to occur in drinking water.

2. Contaminants that have the potential to cause adverse health effects and are 25 demonstrated to occur in drinking water.

3. Contaminants that are demonstrated to cause adverse health effects and that have the potential to occur in drinking water.

4. Contaminants that have the potential to cause adverse health effects and that have the potential to occur in drinking water.

The NRC advises EPA to acquire input from the public and other " stakeholders" on the PCCL. This approach will assist EPA in making any policy judgements about the PCCL and will encourage transparency in the process.

C. Contaminant Selection from the PCCL to the CCL.

The second step is the selection of drinking water contaminants on the PCCL for inclusion on the CCL.

The NRC evaluated a number of screening and assessment processes and recommended that EPA consider the prototype classification method, combined with expert judgement, as an effective approach for selecting contaminants. Prototype classification uses computer based computational tools to weigh selected contaminant characteristics ( also called attributes) against the characteristics of drinking water contaminants that are known to occur in drinking water and are recognized as having negative health impacts. These attributes could include various measures of toxicity, occurrence, and surrogates for these measures where primary data do not exist. A prototype classification algorithm would need to be " trained" to recognize features of contaminants that should be on the CCL by inputting key information about contaminants that we 26 know should and should not be on the CCL.

For demonstration purposes, the NRC used a prototype classification approach known as a " neural network." Neural networks are being used in investment analysis to predict foreign exchange rates, credit worthiness, and signature analysis. The approach relies on expert judgement to determine which attributes should be used to characterize the contaminants and the relative importance of the attributes. The neural network then uses mathematical formulas to evaluate attributes of contaminants against those of known contaminants and makes a prediction based on the importance placed on the contaminants' attributes.

In addition to suggesting a sample prototype classification method, the NRC also identified possible attributes for use in comparing the characteristics of potential contaminants.

They suggested the following attributes: potency, severity, prevalence, magnitude, and persistence mobility. The NRC considered these attributes because of their applicability to both chemicals and microbes, and noted that, after additional analysis and advice, EPA might well determine that other attributes were more appropriate for developing the CCL.

D. Virulence Factor Activity Relationships for Assessing Emerging Waterborne Pathogens.

The NRC also addressed the issue of how best to examine emerging waterborne pathogens, opportunistic microorganisms, and other newly identified microorganisms in Classifying Drinking Water Contaminants for Regulatory Consideration ( NRC, 2001). The panel recognized several difficulties in classifying microbiological drinking water contaminants.

These include difficulties in characterizing microbiological contamination of drinking water, 27 identifying the organism responsible for outbreaks, and developing databases for emerging pathogens. The NRC recommended that EPA explore virulence factor activity relationships ( VFARs) to address this problem. The VFAR principle can be described as comparing the gene structure of newly identified waterborne pathogens to pathogens with known genetic structures which have been associated with human disease.

Virulence factors are defined broadly by the NRC as the ability of a pathogen to persist in the environment, gain entry into a host ( e. g., humans), reproduce, and cause disease or other health problems either because of its architecture or because of its biochemical compounds. A number of virulence factors are known, including the ability of a microbe to move within a host under its own power, the ability of mechanisms to protect the microbe against the body's defenses ( e. g., anti phagocytosis mechanisms), the ability of a microbe to adhere or attach to the surface of a host cell, and the ability of microbes to produce toxins that injure host cells.

Genetic information in the form of gene sequences has been stored in several computerized " libraries" or " gene banks" for the use of the research community. The NRC described several of these gene banks and provides a list of microorganisms whose genomes have already been studied. The NRC noted that the genetic information of additional microbes are being added to gene banks at a rapid pace ( NRC, 2001).

The NRC also recommended that EPA explore the use of gene chip technology ( also referred to as biochips, deoxyribonucleic acid ( DNA) chips, DNA microarrays, and gene arrays)

to assist in classifying drinking water contaminants. Gene chips are devices not much larger than postage stamps. Thousands of tiny cells are typically placed on a glass wafer. Each holds deoxyribonucleic acid, or DNA, from a different human or microbiological gene. The array of 28 cells on a gene chip makes it possible to carry out a large number of genetic tests on a sample at one time. At the moment, the devices are used in pharmaceutical laboratories to investigate which genes are involved in various normal and disease processes and to speed up the process of finding new drugs.

The NRC believed that this approach has major and far reaching potential and indicated that, in the near future, microarrays could be developed that are labeled with genes for a variety of virulence factors and could be used to assay drinking water samples for the presence of genetic virulence factors of concern.

The NRC recognized that use of the VFAR approach to identify potential waterborne pathogens would require a multi year commitment and significant cooperation and collaboration by EPA and other participating organizations before the technology can be used to develop the CCL.

V. Implementation of the National Research Council Recommendations The NRC recommendations provided a possible framework for evaluating a larger number of contaminants and making decisions about contaminants for which data are limited through the use of innovative technologies and expert advice. In making these recommendations, the NRC stressed that more work is needed in the area of research and encouraged EPA to explore different approaches for effective implementation.

The EPA has requested the assistance of NDWAC to evaluate and provide advice on the NRC's recommended classification process. This section describes the role played by NDWAC in 29 assisting EPA's evaluation and implementation of the NRC recommendations and the development of the classification approach.

A. The National Drinking Water Advisory Council Background and Charge.

As previously noted, the 1974 SDWA established NDWAC to provide independent advice, consultations, and recommendations to EPA on matters related to the activities, functions,

and policies of the Agency under SDWA. To assist in this process, the NDWAC forms work groups of experts to perform assessments of specific drinking water issues. The work groups prepare reports and recommendations that the NDWAC considers when making its recommendations to EPA. The NDWAC CCL Work Group began its deliberations in September,

2002. The Work Group is comprised of 21 recognized technical and public health experts representing an array of backgrounds and perspectives.

The NDWAC CCL Work Group is charged with discussing, evaluating, and providing advice to the Agency on methodologies, activities, and analysis needed to implement the NRC recommendations on an expanded approach for the CCL listing process. The EPA is working with the NDWAC CCL Work Group to explore issues related to a contaminant classification approach including ( 1) collecting and organizing the data, ( 2) screening the contaminants in the universe to compile the PCCL, ( 3) classifying contaminants from the PCCL to the CCL, and ( 4)

developing the VFAR concept and classifying microorganisms. The NDWAC CCL Work Group is currently discussing and evaluating the issues related to implementing the NRC recommendations. EPA is assisting the NDWAC CCL Work Group by conducting analyses and 30 investigations that inform the Work Group discussions. The NDWAC CCL Work Group expects to present its recommendations to the NDWAC in 2004.

The NDWAC CCL Work Group and EPA have made great progress in evaluating the NRC recommendations. The EPA recognizes that the recommended approach would require a significant, sustained effort to screen many more data sources for potential CCL contaminants and to adapt computer programs for environmental contaminant selection. The efforts to date have provided substantial information about the scope of the effort and the challenges ahead.

B. Ongoing Analysis of the Classification Approach.

1. Organizing and extracting data.

The NRC recommended that EPA begin by considering a broad universe of chemical,

microbiological, and other types of potential drinking water contaminants and contaminant groups. The NRC projects that the scope of the universe could be on the order of tens of thousands of contaminants, which represent a dramatically larger set of substances to be initially considered in terms of types and numbers of contaminants than that used for the creation of the 1998 CCL ( 262 contaminants from 8 data sources). Considering that there is no comprehensive list of potential drinking water contaminants, and limited data on health effects, occurrence, and other related data for many of the potential contaminants, EPA is challenged with defining the universe of potential drinking water contaminants, determining how it will identify data sources,

and identifying what approach it will use for extracting information. 31 Based on the NRC recommendations, EPA is considering two guiding principles for construction of the CCL universe: ( 1) the universe should include those contaminants that have demonstrated or potential occurrence in drinking water, and ( 2) the universe should include those contaminants that have demonstrated or potential adverse health effects. These inclusionary principles apply to selection of contaminants to be included in the CCL universe. The proposed process involves the identification of information and data sources and the development of a means of extracting data to be merged into a CCL universe data set.

The NDWAC CCL Work Group and EPA have identified a number of data sources as potentially useful resources. The data sources vary widely in their intended use ( e. g., research,

survey, and compliance monitoring); type of data ( e. g., concentrations, health effects, chemical information, microbiological occurrence, environmental fate, and genetic sequences); data format;

availability; and possible applicability to the universe of contaminants. The data sources include the following:

° Databases recommended by the NRC ( NRC 1999a, 1999b, and 2001)

° Databases required by SDWA 1412( b)

° Chemical structure databases ( e. g., molecular structure information used for predictive toxicology)

° Chemical property databases ( e. g., chemical boiling point and solubility)

° Bibliographic databases ( i. e., references to published literature)

° Subscription/ commercial databases ° Genomic sequence databases ° International databases 32 ° Other sources of information recommended by NDWAC and other organizations In addition to data availability and extraction issues, EPA must also address data quality concerns. The Agency is required under SDWA to use the best available peer reviewed science and data collected by accepted methods or best available methods. While the standards of quality depend on the use to which the data is put, and screening level analyses require less rigorous standards than some other uses ( e. g., rule development), the data used to define the CCL universe of contaminants must nonetheless be accurately characterized and its quality clearly understood.

To satisfy these quality assurance objectives, EPA is in the process of developing a Quality Assurance Project Plan to cover all phases of the CCL process, from defining the universe of contaminants to making regulatory determinations.

2. Compiling the PCCL.

The NRC recommended that EPA develop a set of screening criteria that could be applied rapidly and routinely, in conjunction with expert judgement, to screen the universe of potential drinking water contaminants for inclusion on the PCCL. The NRC considered this a significant challenge, but did not deliberate extensively on the criteria to be used for this screening. Thus,

this screening step has become an area of significant analysis by EPA and the NDWAC CCL Work Group. Work to develop a process and criteria for screening is ongoing, as is the analysis of methods that would enable the screening of contaminants with little or no primary data or information.

In addition to exploring screening criteria, EPA is evaluating how expert judgement could 33 be used to quickly reduce a broad universe to a manageable set of contaminants for the PCCL.

While the NRC reports only provided a conceptual recommendation for screening the universe to a PCCL, the NRC indicated that the process should not involve an extensive analysis of data. The NRC suggested that EPA develop coarse screening criteria that can eliminate chemicals with low production volume and low potential for adverse health effects, unless expert judgement of health effects would place a chemical on the PCCL.

As previously described, EPA is coordinating efforts with the NDWAC CCL Work Group to develop a list of occurrence databases to be used in the analysis and will evaluate available human exposure or potential human exposure databases such as production and use databases,

environmental release databases, and environmental media and biological tissues monitoring databases. The toxicological or health effects databases being evaluated include health assessment databases and waterborne disease outbreak databases as well as other information.

For health effects screening, EPA is focusing on contaminants that may be potent at levels near those found in drinking water and substances with irreversible or life threatening health effects. The NDWAC CCL Work Group is considering a number of options for processing data and information in order to examine the relationship between adverse health effects and occurrence in drinking water to make decisions on movement to the PCCL.

3. Classifying contaminants from the PCCL to the CCL.

The challenge of classifying a potentially large number of contaminants for movement from the PCCL to the CCL raises the question of what kind of process or method is best suited 34 for performing this task. The NRC panel recommended the use of a prototype classification approach combined with expert judgement. The EPA has asked NDWAC for advice in this area and is exploring several alternative models including: artificial neural networks, classification and regression trees, logistic regression ( a specific form of a generalized linear model), and multivariate adaptive regression splines. Work is ongoing to identify and test models and conduct trial classifications using a subset of the contaminants that will be in the universe.

Use of the prototype classification approach necessitates assigning a score to each attribute for a given contaminant. Attributes are descriptive properties which allow different types of contaminants to be compared in a consistent manner. The NRC recommended the following attributes: potency ( i. e., the amount of a contaminant that is needed to cause illness);

severity ( i. e., the seriousness of the health effect); prevalence ( i. e., how common does or would a contaminant occur in water); magnitude ( i. e., the concentration or expected concentration of a contaminant relative to a level that causes a perceived health effect); and persistence mobility ( i. e.,

a surrogate for occurrence when occurrence information is unavailable). The EPA and NDWAC CCL Work Group are examining the five attributes recommended by the NRC, as well as exploring other possible attributes.

The EPA and NDWAC CCL Work Group are also exploring how attributes ( e. g.,

potency) for a given contaminant might be scored using differing data elements ( e. g., the reference dose ( RfD), the no observable adverse effect level ( NOAEL), and the lowest observable adverse effect level ( LOAEL)), so that the score for an attribute would reflect the degree of the health effect or occurrence relative to other contaminants.

The NDWAC CCL Work Group and EPA have undertaken significant analysis with 35 regard to the severity attribute. For example, the following range of scores was used by the NRC to represent the severity of a given contaminant for health effects as follows:

0. No effect 1. Changes in organ weights with minimal clinical significance 2. Biochemical changes with minimal clinical significance 3. Pathology of minimal clinical significance 4. Cellular changes that could lead to disease; minimal functional change 5. Significant functional changes that are reversible 6. Irreversible changes, treatable disease 7. Single organ system pathology and function loss 8. Multiple organ system pathology and function loss 9. Disease likely leading to death 10. Death The EPA and NDWAC CCL Work Group are exploring ways that the severity scale provided by the NRC might be modified so that effects in the middle of the scale ( e. g., 4 8) would be more easily differentiated and to allow for appropriate scoring of reproductive and developmental effects. The EPA and NDWAC CCL Work Group are also examining possible approaches to scoring chemicals that lack information on a critical effect for severity.

Similarly, EPA is engaged in substantial technical analysis with the NDWAC CCL Work Group of a possible scoring methodology for the attribute potency. The NRC suggested that potency could be measured in terms of the RfD, the NOAEL, the LOAEL, or by other measures.

Additional issues and challenges the NDWAC CCL Work Group is considering include: 36 1. Which data elements are best suited to estimate the score for an attribute? For example, for the attribute potency, values exist for RfDs, NOAELs, and LOAELs.

2. In what order should data for a given contaminant be considered given the quality,

confidence, and certainty of data sources? For example, should EPA score a contaminant using an RfD over an oral LOAEL if both are available?

3. If no RfD or LOAEL is available, then which value should be used to score a contaminant?

4. Should EPA review all types of data elements even when an RfD exists?

5. How should contaminants be scored when data from different sources suggest conflicting scores?

6. When should surrogates be used in place of the preferred data elements? For example,

using production and release data to estimate the potential for occurrence may be a better approximation than limited sampling in one location.

7. How should surrogates be expressed and scored?

8. For the health effects attributes, which populations should be targeted in scoring ( e. g.,

adults, children, or sensitive subpopulations)? Is it possible to make that distinction given the data that are available?

9. Should an assessment of certainty and confidence be incorporated into the scoring process to reflect the quality of the data?

10. How should scoring for occurrence data elements be addressed?

11. How should subjectivity of severity scoring process be addressed? For example,

some disorders are treatable depending upon when treatment is initiated. How should 37 treatability be accounted for without subjectively referring to a person's ability to obtain medical treatment?

12. What data quality guidelines would be appropriate for classifying contaminants from a PCCL to the CCL? Would different guidelines for screening contaminants be appropriate from a CCL universe to a PCCL?

13. Which models or other approaches would be best suited for classification given the scoring approach?

4. The virulence factor activity relationship concept and classifying microorganisms.

The VFAR process offers a possible alternative to identifying and characterizing microbiological contaminants that lack information. As previously discussed, the VFAR concept can be described as comparing the gene structure of newly identified waterborne pathogens to pathogens with known genetic structures that have been associated with human disease. The NRC recommends the use of the VFAR approach for assessing emerging waterborne pathogens,

opportunistic microorganisms, and other newly identified microorganisms. While this approach may offer significant improvements for the future, it may not be sufficiently developed in time for the next CCL ( i. e., the 2008 CCL). Some of the challenges to overcome include the ability of microbiological genes to exhibit considerable adaptability by frequently gaining or losing genetic elements. The presence of multiple genetic elements, together with the relative frequency of chromosomal recombinations, results in highly dynamic genes that make predictability difficult.

Researchers have mapped about 100 entire genomes of bacteria and viruses, and the 38 number of mapped genomes, especially of pathogens, is growing rapidly. Researchers store the information in several computerized libraries, or gene banks. Sophisticated computer software programs can sort and match genetic information in these libraries, which can allow researchers to predict the ability of a microbe to produce virulence factors, and compare a microbe to known pathogens. Some waterborne pathogens have similar toxins, surface proteins, and mechanisms of infection, and some of the genes for these factors have been identified.

The NDWAC CCL Work Group and EPA are exploring a means of using gene banks for drinking water applications. For example, EPA searched for genetic sequences associated with virulence using the National Center for Biotechnology Information's GenBank database. The database contains a large list of such sequences, most of which are associated with pathogens or microbes used in laboratory studies. Initial findings indicate that some relevant sequence data are available, however, the data were in a form that proved difficult to use for this purpose.

The EPA is also coordinating efforts with the NDWAC CCL Work Group to evaluate an approach based on bioinformatics to extract relevant information from databases and literature sources on known waterborne pathogen gene sequences. The information could provide the gene sequences needed to demonstrate the potential use of gene chip technology in performing VFAR analysis.

The EPA is also exploring alternative approaches to screen microbes for the next CCL,

given the uncertainty surrounding the time frame for a fully developed VFAR approach. For example, EPA is exploring an approach that would construct a microbiological universe, define microbiological attributes, and score the attributes.

The EPA believes that the NRC recommendations hold substantial promise and is 39 exploring ways to take the recommendations beyond the conceptual framework to development and implementation. Additionally, EPA is working with the NDWAC CCL Work Group to define the dimensions of the microbiological universe as part of a step wise process for defining the CCL. The EPA welcomes comments on these and other relevant microbiological issues to assist the Agency in addressing the NRC recommendations.

VI. Request for Comment The EPA seeks comments on the range of CCL issues and activities addressed in this notice. EPA is also requesting comment on its decision to carry over the remaining contaminants on the 1998 CCL as the draft CCL 2. The Agency is asking for public comments on the following questions related to the process for developing the 2008 CCL:

1. Which data sources should the Agency use to assemble the universe of potential CCL contaminants?

2. Should the Agency adopt the general framework of moving from a broad universe of potential candidates to a PCCL and finely to a CCL?

3. If so, what criteria should be used for inclusion of a contaminant on the PCCL, and in selecting contaminants from the PCCL to the CCL?

4. How should EPA address contaminants that lack data on toxicity, occurrence, and exposure?

In addition, the Agency welcomes comments on other aspects of the approach 40 recommended by the NRC.

The EPA expects that public comments on these and other relevant issues will assist the Agency in addressing remaining questions posed by the NRC and the NDWAC and welcomes comments from the public. The Agency recognizes that, while the draft CCL 2 has not been compiled using the new approach recommended by the NRC, many of the underlying principles and objectives remain the same. Information and comments submitted on this notice will be considered in determining the final CCL 2 list, as well as in the development of future CCLs and in the Agency's efforts to set drinking water priorities in the future.

VIII. References NRC. 1999a. Setting Priorities for Drinking Water Contaminants. National Academy Press,

Washington, D. C. http:// www. nap. edu/ catalog/ 6294. html NRC. 1999b. Identifying Future Drinking Water Contaminants. National Academy Press,

Washington, D. C. http:// www. nap. edu/ catalog/ 9595. html NRC. 2001. Classifying Drinking Water Contaminants for Regulatory Considerations. National Academy Press, Washington, D. C.

http:// books. nap. edu/ books/ 0309074088/ html/ index. html 41 [ Drinking Water Contaminant Candidate List 2; Notice  Page 41 of 41]

EPA. 1991. Priority List of Substances Which May Require Regulation Under the Safe Drinking Water Act. Notice. Federal Register Vol 56, No. 9, p. 1470. January 14, 1991.

EPA. 1997a. EPA Drinking Water Microbiology and Public Health Workshop. Washington,

D. C., EPA, Office of Ground Water and Drinking Water, May 20 21, 1997.

Dated:

Benjamin Grumbles,

Acting Assistant Administrator, Office of Water.