[Federal Register Volume 59, Number 114 (Wednesday, June 15, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-14538]


[[Page Unknown]]

[Federal Register: June 15, 1994]


-----------------------------------------------------------------------


ENVIRONMENTAL PROTECTION AGENCY
 

40 CFR Part 52

[MI19-01-5990; FRL-4999-2]

Disapproval of Clean Air Act PM Implementation Plan for Michigan

AGENCY: United States Environmental Protection Agency (USEPA).

ACTION: Notice of proposed rulemaking.

-----------------------------------------------------------------------

SUMMARY: The USEPA today proposes disapproval of the State 
Implementation Plan (SIP) submitted by the State of Michigan for the 
purpose of bringing about the attainment of the National Ambient Air 
Quality Standards (NAAQS) for particulate matter with an aerodynamic 
diameter less than or equal to a nominal 10 micrometers (PM), because 
USEPA finds unapprovable provisions in the consent orders submitted as 
part of the SIP revision. The implementation plan was submitted by the 
State to satisfy certain Federal requirements for an approvable 
nonattainment area PM SIP for Wayne County, Michigan.
DATES: Comments on this proposed action must be received in writing by 
July 15, 1994.

ADDRESSES: Comments should be addressed to: Carlton T. Nash, Chief, 
Regulation Development Section, Air Toxics and Radiation Branch (AT-
18J), United States Environmental Protection Agency, Region 5, 77 West 
Jackson Boulevard, Chicago, Illinois 60604-3590.
    Copies of the State's submittal and other information are available 
for inspection during normal business hours at the following location: 
(It is recommended that you telephone Christos Panos at (312) 353-8328, 
before visiting the Region 5 office.) United States Environmental 
Protection Agency, Region 5, Air and Radiation Division, Air Toxics and 
Radiation Branch, 77 West Jackson Boulevard, Chicago, Illinois 60604-
3590.

FOR FURTHER INFORMATION CONTACT: Christos Panos, Environmental 
Engineer, Regulation Development Section, Air Toxics and Radiation 
Branch (AT-18J), United States Environmental Protection Agency, Region 
5, 77 West Jackson Boulevard, Chicago, Illinois 60604-3590, (312) 353-
8328.

SUPPLEMENTARY INFORMATION:

I. Background

    Michigan was previously required to modify its particulate matter 
SIP by the Clean Air Act Amendments of 1977. On May 22, 1981 (46 FR 
27923), USEPA conditionally approved portions of Michigan's part D 
Total Suspended Particulates (TSP) SIP. In response to USEPA's 
conditional approval the Michigan Department of Natural Resources 
(MDNR) submitted on May 17, 1985 revised rules, which were effective at 
the State level on February 22, 1985 to control TSP from iron and steel 
sources and from other sources in the State.
    On August 7, 1987 (52 FR 29383), USEPA categorized areas of the 
Nation into three groups based on the likelihood that protection of the 
PM NAAQS would require revision of the existing SIP. The USEPA 
identified the entire Wayne County, Michigan area as a PM ``Group I'' 
area of concern, i.e., an area with a strong likelihood of violating 
the PM NAAQS and requiring substantial SIP revision. This Group I area 
was reduced in size on October 31, 1990 and was subsequently designated 
nonattainment for PM (55 FR 45799), and classified as moderate under 
sections 107(d)(4)(B) and 188(a) of the Clean Air Act, upon enactment 
of the Clean Air Act Amendments of 1990.1 See 56 FR 56694 
(November 6, 1991).
---------------------------------------------------------------------------

    \1\The 1990 Amendments to the Clean Air Act made significant 
changes to the Act. See Public Law No. 101-549, 104 Stat. 2399. 
References herein are to the Clean Air Act, as amended (``the 
Act''). The Clean Air Act is codified, as amended, in the U.S. Code 
at 42 U.S.C. 7401, et seq.
---------------------------------------------------------------------------

    On June 11, 1992 (57 FR 24752), USEPA published a final rule which 
approved certain sections of the State's May 17, 1985 submittal, 
because the submittal represented an overall strengthening of the 
existing Michigan SIP and would contribute to general improvement of 
ambient air quality statewide, and disapproved other sections.
    The amended Act required moderate PM nonattainment area SIP 
submittals by November 15, 1991. On November 19, 1991 USEPA received 
revisions to the Michigan SIP for the Wayne County PM nonattainment 
area. The USEPA reviewed the submittal for completeness and found the 
submittal to be incomplete. The USEPA made a finding pursuant to 
section 110(k)(1)(C) of the Act that the State failed to submit a 
complete SIP and notified the Governor in a letter dated December 17, 
1991. See 57 FR 19906 (May 8, 1992). The USEPA's finding of 
incompleteness activated the 18-month clock which could have resulted 
in the imposition of sanctions pursuant to section 179 of the Act. On 
June 11, 1993 the State submitted to USEPA new revisions for the Wayne 
County PM nonattainment area SIP. The submittal was found to be 
complete pursuant to section 110(k)(1) of the Act and USEPA notified 
the State accordingly. This completeness determination corrected the 
State's deficiency under section 179 of the Act and, therefore, 
discharged the 18-month sanctions clock.
    On April 7, 1994 the State submitted to USEPA a SIP revision for 
the Marblehead Lime Company, River Rouge, Michigan. This submittal 
supersedes the portion of the June 11, 1993 Wayne County PM 
nonattainment area SIP submittal applicable to the Marblehead Lime, 
River Rouge facility.
    The air quality planning requirements for moderate PM nonattainment 
areas are set out in subparts 1 and 4 of title I of the Act.2 The 
USEPA has issued a ``General Preamble'' describing USEPA's preliminary 
views on how USEPA intends to review SIP's and SIP revisions submitted 
under title I of the Act, including those State submittals containing 
moderate PM nonattainment area SIP requirements (see generally 57 FR 
13498 (April 16, 1992) and 57 FR 18070 (April 28, 1992)). Because USEPA 
is describing its interpretations here only in broad terms, the reader 
should refer to the General Preamble for a more detailed discussion of 
the interpretations of title I advanced in today's proposal and the 
supporting rationale. In today's rulemaking action on the Michigan 
moderate PM SIP, USEPA is proposing to apply its interpretations taking 
into consideration the specific factual issues presented. Thus, USEPA 
will consider any timely submitted comments before taking final action 
on today's proposal.
---------------------------------------------------------------------------

    \2\Subpart 1 contains provisions applicable to nonattainment 
areas generally and subpart 4 contains provisions specifically 
applicable to PM-10 nonattainment areas. At times, subpart 1 and 
subpart 4 overlap or conflict. EPA has attempted to clarify the 
relationship among these provisions in the ``General Preamble'' and, 
as appropriate, in today's notice and supporting information.
---------------------------------------------------------------------------

    Those States containing initial moderate PM nonattainment areas 
were required to submit, among other things, the following provisions 
by November 15, 1991:

    1. Provisions to assure that reasonably available control measures 
(RACM) (including such reductions in emissions from existing sources in 
the area as may be obtained through the adoption, at a minimum, of 
reasonably available control technology--RACT) shall be implemented no 
later than December 10, 1993;
    2. Either a demonstration (including air quality modeling) that the 
plan will provide for attainment as expeditiously as practicable but no 
later than December 31, 1994 or a demonstration that attainment by that 
date is impracticable;
    3. Quantitative milestones which are to be achieved every 3 years 
and which demonstrate reasonable further progress (RFP) toward 
attainment by December 31, 1994; and
    4. Provisions to assure that the control requirements applicable to 
major stationary sources of PM also apply to major stationary sources 
of PM precursors except where the Administrator determines that such 
sources do not contribute significantly to PM levels which exceed the 
NAAQS in the area. See sections 172(c), 188, and 189 of the Act.

    Some provisions were due at a later date. States with initial 
moderate PM nonattainment areas were required to submit a permit 
program for the construction and operation of new and modified major 
stationary sources of PM by June 30, 1992 (see section 189(a)). Such 
States also were to submit contingency measures by November 15, 1993 
which become effective without further action by the State or USEPA, 
upon a determination by USEPA that the area has failed to achieve RFP 
or to attain the PM NAAQS by the applicable statutory deadline. See 
section 172(c)(9) and 57 FR 13543-13544. These provisions will be 
addressed in separate rulemaking actions.

II. In This Action

    Section 110(k) of the Act sets out provisions governing USEPA's 
review of SIP submittals (see 57 FR 13565-113566). In this action, 
USEPA is proposing to disapprove the SIP revision submitted by the 
State of Michigan to USEPA on June 11, 1993 which completed the 
attainment plan for Wayne County, because it does not meet all of the 
applicable requirements of the Act. The USEPA will consider any 
comments submitted during the public comment period before taking final 
action on today's proposal.

A. Analysis of State Submission

    The State's June 11, 1993 submittal consisted primarily of 31 
consent orders between the State and PM sources. The air quality 
dispersion modeling conducted is based upon control measures, 
limitations, and conditions contained in these orders. The USEPA is 
proposing to disapprove the State's submittal because USEPA finds 
unacceptable language in the consent orders submitted for approval into 
the Michigan SIP. If the State removes the unacceptable language, or 
replaces it with the previously approved version as detailed below, and 
submits revised consent orders, the proposed disapproval will be 
changed to an approval when USEPA takes final action on this submittal.
1. Procedural Background
    The Act requires States to observe certain procedural requirements 
in developing implementation plans and plan revisions for submission to 
USEPA. Section 110(a)(2) of the Act provides that each implementation 
plan submitted by a State must be adopted after reasonable notice and 
public hearing.3 See also section 110(l) of the Act. The USEPA 
also must determine whether a submittal is complete and therefore 
warrants further USEPA review and action (see section 110(k)(1) and 57 
FR 13565). The USEPA's completeness criteria for SIP submittals are set 
out at 40 CFR part 51, appendix V (1991), as amended by 57 FR 42216 
(August 26, 1991). The USEPA attempts to make completeness 
determinations within 60 days of receiving a submission. However, a 
submittal is deemed complete by operation of law if a completeness 
determination is not made by USEPA 6 months after receipt of the 
submission.
---------------------------------------------------------------------------

    \3\Also section 172(c)(7) of the Act requires that plan 
provisions for nonattainment areas meet the applicable provisions of 
section 110(a)(2).
---------------------------------------------------------------------------

    The State of Michigan held a public hearing on March 30, 1993 to 
receive public comment on the implementation plan for the Wayne County 
nonattainment area. Following the public hearing the plan was adopted 
by the State and signed by the Governor's designee and submitted to 
USEPA on June 11, 1993 as a proposed revision to the SIP.
    The SIP revision was reviewed by USEPA to determine completeness 
shortly after its submittal, in accordance with the completeness 
criteria set out at 40 CFR part 51, appendix V (1991), as amended by 57 
FR 42216 (August 26, 1991). The submittal was found to be complete and 
a letter dated June 30, 1993 was forwarded to the Director, Michigan 
Department of Natural Resources, indicating the completeness of the 
submittal and the next steps to be taken in the review process. The 
State's submittal of a complete SIP stopped the sanctions clock 
triggered by USEPA's December 17, 1991 finding that Michigan's November 
15, 1991 submittal was incomplete. As noted in today's action USEPA 
proposes to disapprove the Michigan PM SIP submittal for Wayne County.
    In addition, the State of Michigan held a public hearing on 
February 16, 1994 to receive public comment on the implementation plan 
revision for the Marblehead Lime Company, River Rouge, Michigan. 
Following the public hearing the plan was adopted by the State and 
signed by the Governor's designee and submitted to USEPA on April 7, 
1994 as a proposed revision to the June 11, 1993 SIP submittal 
applicable to the Marblehead Lime, River Rouge facility.
2. Emissions Inventory
    Section 172(c)(3) of the Act requires that nonattainment plan 
provisions include a comprehensive, accurate, current inventory of 
actual emissions from all sources of relevant pollutants in the 
nonattainment area. The emissions inventory should also include a 
comprehensive, accurate, and current inventory of allowable emissions 
in the area. Because the submission of such inventories are necessary 
to an area's attainment demonstration (or demonstration that the area 
cannot practicably attain), the emissions inventories must be received 
with the submission (see 57 FR 13539).
    The State provided thorough documentation of its emissions 
estimates for all sources in the nonattainment area for a 1985 base 
year. The Wayne County area was shown to include 31 facilities. The 
allowable emission rates were calculated based on limits contained in 
Michigan's part 3 Air Pollution Particulate Regulations, limits 
contained in State permits, and limits contained in State consent 
orders. Emissions from roadways and other area source types are 
estimated in accordance with procedures specified in AP-42 and USEPA's 
guidance document, ``Control of Open Fugitive Dust Sources'', using 
inputs that are judged to provide reasonable estimates of these 
emissions.
    The significant sources in the nonattainment area are: (1) Stack 
sources; (2) process fugitive emissions; and (3) area sources such as 
roadways and storage piles. The majority of the facilities in the 
nonattainment area were able to demonstrate attainment of the PM NAAQS 
with RACT level of control. For facilities where this RACT level of 
control was insufficient to demonstrate attainment, certain limits were 
lowered, and various operating conditions were modified to secure 
enough additional reductions to demonstrate attainment. Refinements to 
existing fugitive dust plans were made according to the control 
efficiencies predicted by USEPA's ``Open Fugitive Dust Source Computer 
Model''. These emission limits, production limits, and fugitive dust 
plans are incorporated into the consent orders submitted for approval 
into the Michigan SIP. For further details see the Technical Support 
Document (TSD).
    The USEPA finds that the emissions inventory generally appears to 
be accurate and comprehensive, and provides a sufficient basis for 
determining the adequacy of the attainment demonstration for this area 
consistent with the requirements of sections 172(c)(3) and 110(a)(2)(K) 
of the Act.4
---------------------------------------------------------------------------

    \4\The EPA issued guidance on PM-10 emissions inventories prior 
to the enactment of the Clean Air Act Amendments in the form of the 
1987 PM-10 SIP Development Guideline. The guidance provided in this 
document appears to be consistent with the Act.
---------------------------------------------------------------------------

3. RACM (Including RACT)
    As noted, the initial moderate PM nonattainment areas must submit 
provisions to assure that RACM (including RACT) are implemented no 
later than December 10, 1993 (see sections 172(c)(1) and 189(a)(1)(C)). 
The General Preamble contains a detailed discussion of USEPA's 
interpretation of the RACM (including RACT) requirement (see 57 FR 
13539-13545 and 13560-13561).
    The USEPA has previously judged that existing TSP regulations 
applicable to point sources and contained in part 3 of Michigan's Air 
Pollution Control Commission Rules provide for RACT and have already 
been incorporated into the Michigan SIP (57 FR 24752, June 11, 1992). 
The attainment needs of this area are such that additional measures as 
provided in the current submittal may be considered reasonably 
available. At the same time, further controls beyond those required in 
the submittal and necessary for assuring attainment would not be 
considered reasonable, unless those measures would provide for earlier 
attainment. (See the General Preamble at 57 FR 13560).
    For fugitive dust sources, generic RACT control efficiencies were 
applied to potential emissions based on whether a facility had, and was 
implementing, a fugitive dust plan submitted to and approved by the Air 
Pollution Control Commission5. The generic RACT efficiencies and 
their percent control, as recommended by the Wayne County Air Pollution 
Control Division, are: unpaved roads and lots, 75 percent; paved roads 
and lots, 35 percent; and storage piles and storage pile activities, 50 
percent.
---------------------------------------------------------------------------

    \5\Michigan eliminated the Air Pollution Control Division in a 
recent reorganization. MDNR now handles the responsibilities of the 
former division.
---------------------------------------------------------------------------

    The USEPA has reviewed the State's explanation and associated 
documentation and concluded that it adequately justifies the control 
measures to be implemented. The consent orders in Michigan's submittal 
provide for compliance by October 1, 1993 and the implementation of the 
nonattainment plan control strategy will result in the attainment of 
the PM NAAQS by December 31, 1994, therefore satisfying the 
requirements of sections 172(c)(1) and 189(a)(1)(C) of the Act.
4. Demonstration of Attainment
    As noted, the initial moderate PM nonattainment areas must submit a 
demonstration (including air quality modeling) showing that the plan 
will provide for attainment as expeditiously as practicable but no 
later than December 31, 1994 (See section 189(a)(1)(B) of the Act). 
Alternatively, the State must show that attainment by December 31, 1994 
is impracticable.
    The MDNR conducted an attainment demonstration using dispersion 
modeling for the Wayne County nonattainment area. This demonstration 
indicates that the NAAQS for PM will be attained by 1994 in Wayne 
County and maintained in future years. The 24-hour PM NAAQS is 150 
micrograms/cubic meter (g/m3), and the standard is 
attained when the expected number of days per calendar year with a 24-
hour average concentration above 150 g/m3 is equal to or 
less than one. See 40 CFR 50.6. The annual PM NAAQS is 50 g/
m3, and the standard is attained when the expected annual 
arithmetic mean concentration is less than or equal to 50 g/
m3. The dispersion modeling in the demonstration predicted 146.3 
g/m3 as the 24-hour design concentration, thus 
demonstrating attainment of the 24-hour PM NAAQS. The dispersion 
modeling in the demonstration predicted 49.5 g/m3 as the 
annual design concentration, thus demonstrating attainment of the 
annual PM NAAQS. The control strategy used to achieve these design 
concentrations is summarized in the section titled ``RACM (including 
RACT)''.
    Several factors help assure that the Wayne County nonattainment 
area will maintain as well as attain the standard. First, a substantial 
majority of emissions in the area are from industrial sources and were 
modeled either with maximum allowable emissions (for point sources) or 
with emissions at the sources' full capacity operation (for area 
sources). Thus, the only opportunities for growth in the inventory 
beyond the modeled inventory are new source construction and growth in 
public area sources. The new source review program assures that new 
sources will not create violations of the air quality standards. For 
public area source emissions, the Southeast Michigan Council of 
Governments (SEMCOG) compiled estimates of daily vehicle miles traveled 
(VMT) in Wayne County for a 1985 base year. To account for VMT growth 
in Wayne County, SEMCOG reran their transportation models for the year 
2005. The resulting VMT projections were compared to the 1985 base year 
case and showed a net increase in PM emissions. The increase in 
emissions, however, has already been accounted for in the attainment 
demonstration. Michigan's modeling analysis, reflecting emissions in 
2005, yielded a design value of 146.3 g/m3. Extrapolating 
back to 1994 would yield a design value of 146.1 g/m3. 
Therefore, the State of Michigan has demonstrated maintenance of the 
air quality standard of 150 g/m3 through the year 2005. 
See the TSD for a more detailed description of the attainment 
demonstration and the control strategy used.
5. PM Precursors
    The control requirements which are applicable to major stationary 
sources of PM, also apply to major stationary sources of PM precursors 
unless USEPA determines such sources do not contribute significantly to 
PM levels in excess of the NAAQS in that area (see section 189(e) of 
the Act).
    An analysis of air quality and emissions data for the Wayne County 
nonattainment area indicates that exceedances of the NAAQS are 
attributable solely to direct PM emissions from stack sources, process 
fugitive emissions, and area sources such as roadways and storage 
piles, and not sources of PM precursors. Consequently, USEPA is 
proposing to find that major sources of precursors of PM do not 
contribute significantly to PM levels in excess of the NAAQS. The 
consequences of this finding are to exclude these sources from the 
applicability of PM nonattainment area control requirements. Note that 
while USEPA is making a general finding for this area, today's finding 
is based on the current character of the area including, for example, 
the existing mix of sources in the area. It is possible, therefore, 
that future growth could change the significance of precursors in the 
area. The USEPA intends to issue future guidance addressing such 
potential changes in the significance of precursor emissions in an 
area.
6. Quantitative Milestones and Reasonable Further Progress (RFP)
    The PM nonattainment area plan revisions demonstrating attainment 
must contain quantitative milestones which are to be achieved every 3 
years until the area is redesignated attainment and which demonstrate 
RFP, as defined in section 171(1), toward attainment by December 31, 
1994 (see section 189(c) of the Act). Reasonable further progress is 
defined in section 171(1) as such annual incremental reductions in 
emissions of the relevant air pollutant as are required by part D or 
may reasonably be required by the Administrator for the purpose of 
ensuring attainment of the applicable NAAQS by the applicable date.
    As discussed in the General Preamble (57 FR 13539), attainment 
plans for moderate areas which demonstrate attainment by December 31, 
1994 will satisfy the initial quantitative milestone requirement. The 
consent orders included in Michigan's SIP submittal require compliance 
by October 1, 1993. Given this requirement and the fact that Wayne 
County demonstrates attainment by 1994, USEPA believes the State's 
submission clearly satisfies the initial quantitative milestone 
requirement and demonstrates RFP.
7. Enforceability Issues
    Sections 110(a)(2)(A) and 172(c)(6) of the Act, 42 U.S.C. 
7410(a)(2)(A) and 7502(c)(6), require that each SIP include emission 
limitations and other control measures, means or techniques, and 
schedules or timetables for compliance which are enforceable by the 
State and by USEPA. See also 57 FR 13556. In addition, States must 
include in their nonattainment area SIPS a program to provide for the 
enforcement of the measures described in the SIP. 42 U.S.C. 
7410(a)(2)(C). The USEPA criteria addressing the enforceability of SIPs 
and SIP revisions were provided in a September 23, 1987 memorandum 
(with attachments) from Craig Potter, Assistant Administrator for Air 
and Radiation, et al. (see 57 FR 13541).
    The State of Michigan identified in its submittal particular 
control measures for stack sources, process fugitive dust emissions, 
and area sources such as roadways and storage piles. These control 
measures are addressed in the section entitled ``RACM (including 
RACT),'' above. In its submittal, the State specifies how each control 
measure or limit is made enforceable. The majority of the control 
measures are contained in the existing TSP regulations and, therefore, 
are enforceable as part of the existing Michigan SIP. Some of the 
control measures and applicable recordkeeping requirements, 
particularly those dealing with area sources of PM, are contained in 
the 31 consent orders which the State has requested that USEPA approve 
as part of the Michigan SIP.
    The USEPA finds the consent orders are not approvable as part of 
the Michigan SIP for two reasons. First, each of the 31 consent orders 
contains a provision (paragraph 11) which allows for the substitution 
of ``equivalent'' particulate and fugitive dust control measures. The 
consent orders provide that a company subject to an order may revise 
the control programs contained in the order provided that, among other 
things, neither MDNR nor USEPA objects to the revision within 45 days 
of receipt of the proposal. The USEPA finds that this means of 
modifying the control requirements contained in a consent order, which 
would also (if approved) become part of the Michigan SIP, is 
inappropriate because it bypasses the Act's substantive and procedural 
requirements for SIP revisions. See sections 110(a)(2) and 110(i) of 
the Act, 42 U.S.C. 7410(a)(2) and 7410(i).6
---------------------------------------------------------------------------

    \6\It should be noted that USEPA regulations promulgated 
pursuant to title V of the Act contain provisions under which 
alternative, equivalent emission limits may be incorporated in a 
title V permit. See 40 CFR 70.6(a)(iii). However, these provisions 
are applicable solely in the context of title V permits, and then 
only if the specific requirements in that rule have been met. The 
USEPA further notes that Michigan does not presently have a 
federally approved title V program.
---------------------------------------------------------------------------

    By letter dated October 5, 1992 USEPA Region 5 informed MDNR that 
it could provide sources some flexibility by revising paragraph 11 to 
permit use of those measures specifically outlined in USEPA's PM-10 
Open Fugitive Dust Source Computer Model Package (EPA-450/3-90-010). 
More details on this mechanism are provided in the October 5, 1992 
letter and USEPA's TSD. In its submission, however, Michigan did not 
revise the orders to include this suggested approach.
    Consistent with the above, if, during the public comment period, 
MDNR revises paragraph 11 to delete the provision for substitution of 
``equivalent'' measures, this portion of the consent orders may be 
approved. In the alternative, MDNR may permit the use of the measures 
identified in the Agency's fugitive dust model, in lieu of the 
provision for substitution of ``equivalent'' measures, in accordance 
with USEPA's October 5, 1992 letter.
    In addition, each of the 31 consent orders provides for termination 
upon the issuance of an operating permit pursuant to title V of the Act 
(paragraph 12). Each title V operating permit, however, must include 
all Clean Air Act provisions necessary to assure compliance with the 
applicable requirements of the Act, including those in the SIP. See 42 
U.S.C. 7661c(a). Therefore, the requirements contained in the title V 
operating permit are to be those substantive requirements applicable 
under other provisions of the Act, such as the SIP. For that reason, 
the consent orders must not expire, even following issuance of the 
operating permits.7 The TSD contains further information on the 
enforceability of the consent orders.
---------------------------------------------------------------------------

    \7\The USEPA would not consider a valid termination of the 
consent orders included in the SIP to have occurred unless and 
until: The State issues a title V permit that contains the 
provisions in the consent order; the State submits to USEPA a SIP 
revision providing for replacement of the consent order with the 
substitute permit; and USEPA approves the permit provisions as a SIP 
revision.
---------------------------------------------------------------------------

8. Ligninsulfonate Dust Suppressant
    As stated earlier, MDNR used USEPA's ``Open Fugitive Dust Source 
Computer Model'' to determine control efficiencies for various 
combinations of chemical application rates and treatment frequencies 
applicable to fugitive dust roadway emissions. The model lists watering 
or chemical suppressants as two possible control options for unpaved 
roads. Average efficiency curves were generated for four chemical dust 
suppressants and, because there was little data available at the time, 
the program was designed to be very general without any reference to a 
specific chemical or brand name. The model allows for comparisons 
between watering and chemicals, and between the chemicals originally 
considered in the generation of the model, but not for the substitution 
of suppressants other than the four types originally considered by the 
model. Ligninsulfonate was not one of the four chemicals originally 
evaluated by USEPA's model.
    Ligninsulfonate has been utilized as a dust suppressant since the 
early 1900's in Sweden and its use in this country dates to the 1940's. 
Only one company in the nonattainment area (Levy, at five locations) 
currently uses ligninsulfonate for dust suppression. The MDNR 
investigated the relationship between the control efficiencies for 
lignin suppressants relative to the ones considered in the computer 
model to correlate the use of lignins to the use of the original four 
suppressants. MDNR determined that if lignins are applied at a chemical 
rate 2.3 times that of the chemicals considered in USEPA's computer 
model, then the efficiency predicted by the model can be applied to 
uncontrolled emission rates from unpaved roads being treated with 
ligninsulfonate given equal treatment frequencies. The USEPA believes 
that the data that has been submitted by the State of Michigan is 
comparable to the original data used to determine the control 
efficiencies of the dust suppressants included in the model, and, 
therefore, is adequate to technically support the use of 
ligninsulfonate as an alternative suppressant. See the TSD for further 
details.
9. Contingency Measures
    As provided in section 172(c)(9) of the Act, all moderate 
nonattainment area SIP's that demonstrate attainment must include 
contingency measures. See generally 57 FR 13543-13544. These measures 
should consist of other available measures that are not part of the 
area's control strategy and must take effect without further action by 
the State or USEPA, upon a determination by USEPA that the area has 
failed to make RFP or attain the PM NAAQS by the applicable statutory 
deadline. As noted, States with initial moderate nonattainment areas 
were not required to submit the contingency measures required in 
section 172(c)(9), until November 15, 1993. The USEPA will determine 
the adequacy of such submittal as appropriate in a separate rulemaking.

III. Implications of This Action

    The USEPA is proposing to disapprove in its entirety the SIP 
revision submitted by the State of Michigan on June 11, 1993 for the 
Wayne County PM nonattainment area because USEPA finds unapprovable 
provisions in each of the 31 consent orders submitted as part of the 
SIP revision. If the State removes the unacceptable language in 
paragraph 11, or replaces it with the previously approved version 
mentioned above, and removes paragraph 12 in each of the 31 consent 
orders, and submits revised consent orders which USEPA finds 
acceptable, the proposed disapproval would be changed to an approval 
when USEPA takes final action on this submittal. If finalized, this 
disapproval would constitute a disapproval under section 179(a)(2) of 
the Act (see generally 57 FR 13566-13567). As provided under section 
179(a) of the Act, the State of Michigan would have up to 18 months 
after a final SIP disapproval to correct the deficiency that is the 
subject of the disapproval before USEPA is required to impose either 
the highway funding sanction or the requirement to provide two-to-one 
new source review offsets. If the State has not corrected its 
deficiency within 6 months thereafter, USEPA must impose the second 
sanction. Any sanction USEPA imposes must remain in place until USEPA 
determines that the State has come into compliance.

IV. Request for Public Comments

    The USEPA is requesting comments on all aspects of today's 
proposal, including USEPA's proposed decision to impose the two to one 
new source review offset requirement as the first sanction should USEPA 
ultimately disapprove this submittal in whole or in part and the State 
fails to timely remedy the deficiency. As indicated at the outset of 
this document, USEPA will consider any comments received by July 15, 
1994.

V. Executive Order 12866

    This action has been classified as a Table 2 action by the Regional 
Administrator under the procedures published in the Federal Register on 
January 19, 1989 (54 FR 2214-2225), as revised by an October 4, 1993 
memorandum from Michael H. Shapiro, Acting Assistant Administrator for 
Office of Air and Radiation. A future document will inform the general 
public of these tables. On January 6, 1989 the Office of Management and 
Budget (OMB) waived Table 2 and 3 SIP revisions (54 FR 2222) from the 
requirements of section 3 of Executive Order 12291 for 2 years. The 
USEPA has submitted a request for a permanent waiver for Table 2 and 3 
SIP revisions. The OMB has agreed to continue the waiver until such 
time as it rules on USEPA's request. This request continues in effect 
under Executive Order 12866 which superseded Executive Order 12291 on 
September 30, 1993. OMB has exempted this regulatory action from E.O. 
12866 review.

VI. Regulatory Flexibility

    Under the Regulatory Flexibility Act, 5 U.S.C. 600 et seq., USEPA 
must prepare a regulatory flexibility analysis assessing the impact of 
any proposed or final rule on small entities. 5 U.S.C. 603 and 604. 
Alternatively, USEPA may certify that the rule will not have a 
significant economic impact on a substantial number of small entities. 
Small entities include small businesses, small not-for-profit 
enterprises, and government entities with jurisdiction over populations 
of less than 50,000.
    The USEPA's disapproval of the State request under section 110 and 
subchapter I, part D of the Act does not affect any existing 
requirements applicable to small entities. Any pre-existing Federal 
requirements remain in place after this disapproval. Federal 
disapproval of the State submittal does not affect its state-
enforceability. Moreover, USEPA's disapproval of the submittal does not 
impose any new Federal requirements. Therefore, USEPA certifies that 
this disapproval action does not have a significant impact on a 
substantial number of small entities because it does not impose any new 
Federal requirements.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Particulate matter, Reporting and recordkeeping 
requirements.

    Authority: 42 U.S.C. 7401-7671q.

    Dated: June 2, 1994.
Michelle D. Jordan,
Acting Regional Administrator.
[FR Doc. 94-14538 Filed 6-14-94; 8:45 am]
BILLING CODE 6560-50-F