[Federal Register Volume 61, Number 37 (Friday, February 23, 1996)]
[Notices]
[Pages 6967-6970]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-3804]



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DEPARTMENT OF AGRICULTURE

Conformity Determination for the Proposed Carlota Copper Project, 
Pinal and Gila Counties, AZ

AGENCY: Forest Service, USDA.

ACTION: Notice of availability.

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SUMMARY: In accordance with the federal Conformity Rule (November 15, 
1993, 40 CFR 51.850-51.860), the United States Department of 
Agriculture, Forest Service--Tonto National Forest (Tonto NF) has 
reviewed the air quality analysis conducted for the proposed Carlota 
Copper Project to be located within the Hayden/Miami, Arizona, planning 
area that has been designated a nonattainment area for particulate 
matter less than 10 microns in aerodynamic diameter (PM10) and 
sulfur dioxide (SO2). The Tonto NF's review has been conducted 
consistent with the requirements of 40 CFR Part 93, Subpart B: 
``Determining Conformity of General Federal Activities to State or 
Federal Implementation Plans (SIP)'', issued on November 30, 1993.
    The Tonto NF has determined that total annual emissions of SO2 
from the proposed project are less than the de minimis mission 
threshold (40 CFR Part 93) that triggers the requirement to conduct a 
conformity determination.
    Annual PM10 emissions have been determined to exceed the 
PM10 de minimis threshold and the Tonto NF has prepared a 
conformity determination for this pollutant. As per the requirement in 
40 CFR 93.153(h)(1), this Federal Register notice lists the proposed 
activities that are presumed to conform and the basis for the 
presumptions. A comprehensive presentation of the bases for the 
conformity presumptions are included in the report, ``Conformity 
Determination: Carlota Copper Project,'' USDA, Forest Service--Tonto 
National Forest, February, 1996. This document 

[[Page 6968]]
is currently available for public review and comment.

DATES: Public comment period ends March 25, 1996.

ADDRESSES: The report, ``Conformity Determination: Carlota Copper 
Project,'' USDA, Forest Service--Tonto National Forest, February, 1996, 
is available for public review at the following locations: Tonto 
National Forest Supervisor's Office, Phoenix, AZ; Globe Ranger District 
Office, Globe, AZ. All comments should be in writing and sent to: 
Forest Supervisor, Tonto National Forest, 2324 E. McDowell Road, 
Phoenix, AZ 85006.

FOR FURTHER INFORMATION CONTACT: Paul M. Stewart, Tonto National 
Forest, 2324 E. McDowell Road, Phoenix, AZ 85006, (602) 225-5200.

SUPPLEMENTARY INFORMATION:

I. Background

    The Carlota Copper Company has submitted a Plan of Operations 
(1992) and a subsequent Update to the Plan of Operations (1993) to the 
Globe Ranger District of the United States Department of Agriculture 
(USDA) Forest Service--Tonto National Forest (Tonto NF) for the 
construction, operation, and reclamation of the Carlota Copper Project 
(project), a copper mining and processing operation. The proposed 
project is located on lands administered by the Tonto NF. Specifically, 
the project is located in Gila and Pinal Counties, approximately 7 
miles west of Miami, Arizona.
    A portion of the project is proposed to be located in the northern 
part of an area that has been designated by the United States 
Environmental Protection Agency (EPA) as a nonattainment area for the 
annual and 24-hour National Ambient Air Quality Standard (NAAQS) for 
particulate matter less than 10 microns in aerodynamic diameter 
(PM10). The first phase of the PM10 nonattainment designation 
occurred August 7, 1987, (52 FR 29383) when EPA identified and listed 
the Group I and Group II areas in each state. The Hayden/Miami planning 
area was designated a Group I area. A Group I area is an area that has 
been estimated by EPA to have a 95 percent or greater probability of 
exceeding the PM10 standards. (Hayden Area SIP/PM10, p. 14).
    On March 15, 1991, EPA designated all Group I areas as 
``nonattainment'' for PM10. At the same time, EPA announced that 
all areas designated as nonattainment for PM10 were classified as 
``moderate'' nonattainment areas. Therefore, the Hayden/Miami planning 
area is classified as a moderate nonattainment area for PM10. A 
moderate area is a nonattainment area that the Administrator has 
determined can practicably attain the NAAQS for PM10 by the 
attainment date for moderate areas (as expeditiously as practicable but 
no later than the sixth calendar year after the area's designation as 
nonattainment). (Clean Air Act, Section 188 a-c.) The Hayden/Miami 
planning area consists of:
     Townships: T4S, R16E; T5S, R16E; T6S, R16E,
     The portion of Township T3S, R16E that does not lie on the 
San Carlos Indian Reservation, and
     The rectangle formed by, and including Townships: T1N, 
R13E; T1N, R15E; T6S, R13E; T6S, R15E.
    The portion of the project area that is within the moderate 
nonattainment area is in the rectangle formed by the four townships. 
Specifically, the project area is located within Township T1N, R13E.
    The area has also been classified as a Priority 1A Region (40 CFR 
52.120) for sulfur dioxide (SO2). States are required to prepare 
and submit a SIP that demonstrates attainment and maintenance of the 
NAAQS in Priority I Regions. The Priority 1``A'' classification is for 
any area that has been designated a Priority 1 region primarily because 
of emissions from a single source. In this case, the designation is 
based on copper smelting operations in Hayden, Arizona. The area is in 
attainment of all other criteria pollutants: carbon monoxide, nitrogen 
dioxide, lead, and ozone.
    Section 110 of the Clean Air Act requires that the State of Arizona 
prepare and submit to the EPA a State Implementation Plan (SIP) to 
reduce particulate emissions to achieve and maintain attainment of both 
the SO2 and PM10 NAAQS. The Arizona Department of 
Environmental Quality (ADEQ) has developed a PM10 SIP designed to 
reduce and maintain ambient concentrations of PM10 to levels below 
the NAAQS for PM10. EPA has proposed partial approval of the 
Hayden/Miami PM10 SIP. To date, there has been no final approval 
of the SIP. ADEQ is in the process of developing the SO2 SIP.
    Due to the proposed location of the project in the nonattainment 
area and the Tonto NF's affirmative role as Federal Land Manager, the 
Tonto NF has the responsibility under the Conformity Rule (November 15, 
1993, CFR 51.850-51.860) to make a determination as to whether the 
proposed project conforms with all aspects of the applicable SIP for 
the area. The Tonto NF has reviewed the air quality analysis conducted 
for this project consistent with the requirements of 40 CFR Part 93 
Subpart B: ``Determining Conformity of General Federal Actions to State 
or Federal Implementation Plans (SIP)'', issued on November 30, 1993.
    The Tonto NF has determined that total annual emissions of SO2 
from the project are less than the de minimis emission threshold (40 
CFR Part 93) that triggers the requirement to conduct a conformity 
determination. Therefore, although the Hayden area has been designated 
a nonattainment area for SO2, a conformity determination for 
SO2 emissions is not required. Annual PM10 emissions have 
been determined to exceed the de minimis threshold and the Tonto NF has 
determined that a conformity determination is required for PM10.

II. Requirements of the Conformity Determination

    The purpose of the conformity analysis is to establish the Carlota 
Copper Project's conformity with the Hayden area PM10 SIP, thereby 
demonstrating that total direct and indirect emissions from the project 
will not:
     cause or contribute to any new violation of any standard 
in the area,
     interfere with provisions in the applicable SIP for 
maintenance of any standard,
     increase the frequency or severity of any existing 
violation of any standard in any area, or
     delay timely attainment of any standard or any required 
interim emission reductions or other milestones in the SIP for purposes 
of
    (a) a demonstration of reasonably further progress (RFP),
    (b) a demonstration of attainment, or
    (c) a maintenance plan.
    For the purposes of a conformity determination, direct and indirect 
emissions are defined as follows (40 CFR 93.152):
     Direct Emissions: Those emissions of a criteria pollutant 
or its precursors that are caused or initiated by the Federal action 
and occur at the same time and place as the action;
     Indirect Emissions: Those emissions of a criteria 
pollutant or its precursors that:
    1. Are caused by the Federal action, but may occur later in time 
and/or maybe further removed in distance from the action itself but are 
still reasonably foreseeable; and
    2. The Federal agency can practicably control and will maintain 
control over due to a continuing program responsibility of the Federal 
agency.
    For the Carlota Copper Project, the Tonto NF has determined that 
the emissions inventory prepared for the air 

[[Page 6969]]
quality analysis includes the total of direct and indirect emissions 
from the project. The Tonto NF has determined that the emissions of 
concern with regard to PM10 SIP conformity of the emission sources 
at the proposed Carlota Copper Project are restricted to PM10 
emissions. The basis for designation of the area as nonattainment was 
PM10 emissions (not precursors) from mining activities (associated 
with smelting activities in Hayden, AZ). Precursors of PM10 were 
also not incorporated in the SIP analysis for the nonattainment area. 
The Tonto NF maintains that a conformity determination based on 
PM10 emissions will be adequate to assess SIP conformity and to 
protect the PM10 NAAQS at the process area boundary.
    Emissions from process and non-process sources at the project are 
direct emissions under the definition above. The Tonto NF has 
determined that the hourly and annual emission estimates prepared for 
the air quality analysis are representative of PM10 emission rates 
over the life of the project and that the distribution of emission 
sources in the modeling analysis is representative of the spatial 
extent of the emissions sources over the life of the project. Further, 
the Tonto NF has not identified any other emissions or emissions 
sources that the Tonto NF can practicably control or maintain control 
of due to a continuing program responsibility at the project. The 
report, ``Conformity Determination: Carlota Copper Project,'' USDA, 
Forest Service--Tonto National Forest, February 1996, includes a 
detailed description of emission sources and controls at the project.
    The PM10 nonattainment designation for the Hayden/Miami 
planning area is a result of expected exceedances of the PM10 
NAAQS proximate to the copper smelting activities in the town of 
Hayden. As a result, the ``design value'' (i.e., the predicted ambient 
level of PM10 upon which the controls in the SIP are based) 
pertains to particulate levels in Hayden, as opposed to the proposed 
project site. Furthermore, particulate emission control measures in the 
SIP pertain only to control of PM10 emissions at two specific 
copper smelters (and associated activities) located in Hayden. Hayden 
is located in the southern tip of Gila County, approximately 25 miles 
south of the proposed project.
    The results of the impact modeling analysis used for this 
conformity determination indicate that the Carlota Copper Project is 
not expected to cause any increase in ambient PM10 levels in the 
Hayden area. The most distant receptor to the south of the project (in 
the direction of Hayden) is approximately 6 miles due south of the 
center of the proposed process area. The maximum predicted 24-hour and 
the annual average PM10 impacts at this receptor are predicted to 
be less than 6.8 /m3 and 0.3 /m3, 
respectively. Hayden is four times further away from the Carlota Copper 
Project that this receptor. The model results suggest that particulate 
impacts at Hayden, 25 miles to the south of the project, would be 
negligible (or zero). (The report, ``Conformity Determination: Carlota 
Copper Project,'' USDA, Forest Service--Tonto National Forest, February 
1996, includes a description of modeling approach, presents the results 
of the modeling analyses, and includes printouts of the input and 
output files of the modeling analyses.)
    On November 10, 1994, ADEQ petitioned EPA to re-align the Hayden/
Miami PM10 nonattainment are boundary. Based on topographical and 
climatological differences, as well as no monitored exceedances of the 
PM10 NAAQS in the Miami area, ADEQ requested that Townships T1N, 
R13E-R15E and T1S, R13E-R15E be excluded from the nonattainment area. 
This area includes the proposed Carlota Copper Project area. This 
petition, and the history of monitored compliance with the NAAQS in 
Miami, underscores the fact that the air quality issues addressed in 
the SIP do not pertain to air quality issues in the project area.
    Based on this information, the Tonto NF has determined that this 
conformity determination is to establish through a local modeling 
analysis that PM10 emissions from the proposed project will not 
create any new exceedances of the PM10 NAAQS. The other conformity 
criteria (listed in the first paragraph of this section) are not 
applicable to the Carlota Copper Project due to the conditions of the 
nonattainment area, the ambient levels of PM10 at the project 
site, and the source specific controls in the SIP.
    The final Conformity Rule (40 CFR 93) specifically allows for the 
use of a local modeling analysis for a conformity determination. 40 CFR 
93.158.a.4.i stipulates:

    Where the State agency primarily responsible for the applicable 
SIP determines that an area-wide air quality modeling analysis is 
not needed, the total of direct and indirect emissions from the 
action meet the requirements specified in paragraph (b) of this 
section, based on local air quality modeling analysis * * *

    Paragraph (b) requires that the local air quality modeling analysis 
must show that an action does not cause or contribute to any new 
violation of any standard in any area, nor does the action increase the 
frequency or severity of any existing violation of any standard in any 
area. Paragraph (b) also requires that requirements and milestones in 
the SIP must not be violated. (There are no requirements or milestones 
that apply to any sources other than the identified smelter sources in 
Hayden.) A complete air quality analysis and identification of any 
necessary mitigation measures is also required by paragraph (b).
    Lastly, paragraph (b) requires that a local air quality analysis 
must meet the applicable requirements of 40 CFR 93.159, Procedures for 
Conformity Determinations of General Federal Actions. The applicable 
requirements of 93.159 are:
     The analysis must be based on the latest and most accurate 
emission estimation techniques available for stationary and area 
sources of emissions, defined as the latest emission factors specified 
by EPA in AP-42 (``Compilation of Emission Factors''), unless more 
accurate emission data are available (93.159.b.2):
     The analysis must be based on the applicable air quality 
models, data bases, and other requirements specified in the most recent 
version of the ``Guideline on Air Quality Models (Revised)'' (1986) 
including supplements (93.159.c); and
     The analysis must be based on the total of direct and 
indirect emissions from the action and must reflect emission scenarios 
that are expected to occur the year during which total emissions are 
expected to be the greatest on an annual basis (93.159.d.2).
    As an option to a modeling analysis, 40 CFR 93.158 allows an action 
to fully offset its emissions within the same nonattainment area 
through a revision to the applicable SIP or an equally enforceable 
measure that effects emission reductions equal to or greater than the 
total of direct and indirect emissions from the action so that there is 
no net increase in emissions of that pollutant (93.158.a.5.iii). The 
Tonto NF has determined that since the local modeling analysis 
satisfies the requirements of paragraph (b) and because there is not a 
fully approved SIP for the Hayden/Miami are that could be revised to 
include offsets, the local modeling analysis allowed for in 93.158.a.4 
is adequate for determining the conformity of the action.

III. Presumption of Conformity

    The Globe Ranger District of the United States Department of 
Agriculture (USDA) Forest Service--Tonto National Forest has reviewed 
the air quality 

[[Page 6970]]
analysis conducted for the Carlota Copper Project (consistent with the 
requirement of 40 CFR Part 93, ``Determining Conformity of General 
Federal Actions to State or Federal Implementation Plans (SIP)'', 
issued on November 30, 1993.
    For purposes of emissions of sulfur dioxide (SO2), the project 
is proposed to be located in an area designated as nonattainment for 
SO2, although there is not an approved SO2 SIP for the 
nonattainment area. The Tonto NF has reviewed the air quality analysis 
and determined that predicted direct and indirect emissions of SO2 
are 26 tons per year. This is below the de minimis level of 100 tons 
per year for SO2 as defined in the general conformity rule (40 CFR 
93.153). Since the proposed facility conforms with the allowed 
emissions limitation, no further conformity determination was deemed 
necessary.
    For purposes of emissions of particulate matter with aerodynamic 
diameter less than 10 microns (PM10), the project is proposed to 
be located in an area designated as a moderate nonattainment area of 
PM10. The air quality analysis for the project indicates that 
predicted direct and indirect emissions of PM10 exceed the de 
minimis level for moderate PM10 areas (100 tons per year). 
Therefore, the Tonto NF has reviewed the local PM10 emissions 
modeling analysis for the project and has determined the following:
     The methods for estimating direct and indirect emissions 
from the project meet the requirements of 40 CFR 93.159. The emissions 
scenario used in the air quality analysis is expected to produce the 
greatest off-site impacts on a daily and annual basis. (A detailed 
description of the emission sources and detailed emissions inventory 
tables are included in the report, ``Conformity Determination: Carlota 
Copper Project,'' USDA, Forest Service--Tonto National Forest, 
February, 1996.)
     The local PM10 emissions modeling methodology is 
appropriate for determining whether emissions from the project will 
cause or contribute to any new violation of the PM10 National 
Ambient Air Quality Standard (NAAQS) and meet the requirements of 40 
CFR 93.159. (A detailed description of the local PM10 emissions 
modeling methodology is included in the report, ``Conformity 
Determination: Carlota Copper Project,'' USDA, Forest Service--Tonto 
National Forest, February, 1996.)
     The results of the modeling analysis predict maximum 24-
hour ambient concentrations at the process area boundary to be 110.8 
/m3. This is below the 24-hour PM10 NAAQS of 150 
/m3. (A detailed description of the modeling analysis 
results and the printouts of the model input and output files are 
included in the report, ``Conformity Determination: Carlota Copper 
Project,'' USDA, Forest Service--Tonto National Forest, February, 
1996.)
     The results of the modeling analysis predict the maximum 
average annual ambient concentration at the process area boundary to be 
36.9 /m3. This is below the annual PM10 NAAQS 
standard of 50 /m3.
     The action does not cause or contribute to any new 
violation of any standard in any area (40 CFR 93.158.b.2.i).
     The action does not increase the frequency or severity of 
any existing violation of any standard in any area (40 CFR 
93.158.b.2.ii).
     The action does not violate any requirements or milestones 
in the SIP (no requirements or milestones are applicable to the project 
(40 CFR 93.158.c).
    Based on these determinations, the activities at the Carlota Copper 
Project is presumed to conform to the applicable SIPs for the project 
area. The list of activities at the Carlota Copper Project that are 
presumed to conform include:

------------------------------------------------------------------------
                  Process                            Non-process        
------------------------------------------------------------------------
Primary crusher system....................  Topsoil removal.            
Conveyor systems..........................  Topsoil unloading to        
                                             stockpiles.                
Secondary crusher system..................  Blast hole drilling.        
Boiler....................................  Blasting.                   
Back-up generator.........................  Loading/unloading of ore and
                                             mine rock.                 
                                            Hauling or ore and mine     
                                             rock.                      
                                            Combustion emissions from   
                                             mobile equipment.          
                                            Travel of mine equipment    
                                             other than haul trucks.    
                                            Haul road maintenance.      
------------------------------------------------------------------------

    This presumption of conformity assumes that adequate activity 
limits, emission limits, emission controls, and monitoring requirements 
will be included in the Air Installation Permit for the Carlota Copper 
Project and will be adequately enforced by the issuing agency, the 
Arizona Department of Environmental Quality.

    Dated: February 13, 1996.
Charles R. Bazan,
Forest Supervisor.
[FR Doc. 96-3804 Filed 2-22-96; 8:45 am]
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