Environmental  Information
     PREVENTING SIGNIFICANT DETERIORATION OF AIR QUALITY
                    IN CLEAN AIR  AREAS
INTRODUCTION

     A major  purpose of the Clean  Air Act of 1970 is  "to
protect and enhance the quality  of the Nation's air resources
so as to promote the public health and~welfare and the pro-
ductive capacity of its population."  The Act is administered
by the U.S. Environmental  Protection Agency (EPA).

     Under  the Act, States are required to develop and carry
out State Implementation Plans (SIPs) to achieve and maintain
national  ambient air quality standards established by EPA.
The standards set clean air goals  to protect health (primary
standards)  and welfare (secondary  standards).

     The Act  has been interpreted  by the courts as,also barring
degradation of air in areas that are cleaner than the national
ambient air quality standards require.

     EPA has  issued regulations  to provide ways in which  States
can protect air quality in areas where the air is already
cleaner than  is required by the  standards.  The background  of
these regulations is this:

     On May 30, 1972, as a result  of a suit filed by the  Sierra
Club, EPA was ordered by the District Court of the District of
Columbia to disapprove all State Implementation Plans which did
"not prevent  significant deterioration of air' quality" in
currently clean air areas..  EPA  was ordered to publish regu-
lations to  this effect.  The District Court order was appealed
by EPA to the U.S. Court of Appeals where it was affirmed,  and
subsequently  to the U.S. Supreme Court where it was affirmed  by
a tie vote.

     Following the initial court action, EPA disapproved all
State Implementation Plans which did not explicitly "prevent
significant deterioration."

     There  was no firm judicial  or legislative guidance available
to EPA on what constituted significant deterioration or on  how
to prevent  such deterioration.  Nevertheless, after extensive
public comment was analyzed, EPA published final regulations  in
the Federal Register on December 5, 1974.
      U.S. ENVIRONMENTAL PROTECTION AGENCY, WASHINGTON, D.C. 20460

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 WHAT THE REGULATIONS DO

      The regulations establish three classifications of air
 quality levels based on how much increase will be permitted
 .in ambient concentrations of particulate matter, such as dust,
 soot and smoke, and of sulfur dioxide.

      Class I — regions where practically any air quality deteri-
 oration would be considered significant.  In this class, the
 annual  mean increases in present pollution levels would be
 limited to five micrograms of particulates per cubic meter of
 air and to two micrograms of sulfur dioxide per cubic meter
 of air.

      Class  Il — regions  where deterioration in  air quality  that
 would normally accompany moderate,  well-planned growth, would
 not be  considered  significant.   The allowable  annual  mean
 increase would be  limited to 10  micrograms of  particulates and
 15 micrograms of sulfur dioxide  per cubic meter of air.

      Class  Ill — regions where intensive major  industrial growth
 is desired.   But  levels of particulates and sulfur dioxide
 would not  be  allowed to rise oeyond the point  of the  most
 stringent  Federal  air standards  to  protect the public health
 and welfare.

      EPA designated  all  areas  of  the  country as  Class II bearing
 in mind the  twin objectives  of the  Clean  Air Act to  protect  air
 quality and  "promote...productive capacity."

 REDESIGNATION

      Under  the  EPA regulations,  the States  (including sovereign
 Indian  governing bodies)  may  request  redesignation  of an area
 to Class I  or  Class  IM.   Managers  of Federal  land, however,  may
 request redesignation only  from Class II  to  Class  I.

     The redesignation  of  an area may be  necessary  to  achieve
 the social, economic  or environmental objectives  of its  popu-
 lation  or of  the Nation as a whole.  The  regulations  give  the
 primary decision-making responsibility  to  the States  to help
 them achieve  their various objectives.

     Requests  for redesignation must reflect full consideration
 of environmental, economic and social effects of  the  classification
 change  on the affected area and on the surrounding region  and
 the Nation as we!1.

     The public must be  involved.  Full  public participation
 is an  essential element  of the redesignation process.  An
analysis of the anticipated effects  of a classification change
must be made available to the public prior to and at a public
hearing on  the proposed  redesignation.

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HOVJ THE REGULATIONS  WORK
     The prevent-on  of significant  air  quality deterioration
is to be achieved by a review  of  major  sources of  industrial
air pollution prior  to plant construction.  A list  of the
industries regulated follows:
     1.  Fossil-fuel  fired  steam  electric plants of more than
         1,000 million B.T.U.  per hour  input.
     2.  Coal cleaning plants  (i.e.,  thermal dryers).
     3.  Kraft pulp  mills  (i.e.,  recovery furnaces).
     4.  Portland cement plants.
     5.  Primary zinc smelters.
     6.  Iron and steel  mills  (i.e.,  metallurgical  furnaces).
     7.  Primary aluminum  ore  reduction plants.
     8.  Primary copper smelters.
     9.  Municipal  incinerators  capable of  burning more  than
         250 tons of refuse per  day.
    10.  Sulfuric acid plants.
    11.  Petroleum refineries.
    12.  Lime plants.
    13.  Phosphate rock processing  plants.
    14.  By-product  coke oven  batteries.
    15.  Sulfur recovery plants.
    16.  Carbon black plants  (i.e., furnace process).
    17.  Primary lead smelters.
    18.  Fuel conversion plants.
    19.  Ferroalloy  production facilities.
     EPA has established criteria published in  the September 10,
1975, Federal Register to add  other source  categories.   Such
sources would be those that emit more than  25  pounds  per hour
of particulate matter or sulfur  dioxide and have a New  Source
Performance Standard.  (This  standard limits  emissions  from new
industrial plants.)

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      EPA significant deterioration  regulations  require  that  new
 or modified sources use the best available  control  technology
 to limit their emissions.   Industrial  development  in  clean areas
 will  not only be well  planned  and orderly but will  cause  less
 pollution than earlier developed industrialized  areas.,  which
 now must be cleaned up.

      Applications  for  permission to  build any of these  new air
 pollution sources  will  not  be  approved  without  a determination
 that  the air quality level  in  the class  concerned  will  not be
 exceeded.

      The regulations offer  the  States  and local  governments
 an  opportunity to  assume responsibility  to  review  and approve
 applications  for new industrial  development.

      Decisions arising  from the  new  regulations  are too important
 to  be  left  to  technicians alone.  Government at  all levels must
 seek  out the  advice  of  affected  and  interested  citizens to help
 make  these  decisions.   And  citizens  should  make  themselves heard.

      EPA had  to  decide  what degree of air quality  deterioration
 would  be  considered  "significant."   In areas having very  clean
 air,  it  was  not  possible to  set  standards based  on any measure-
 ments  of damage  to  the  public health or welfare.   On the  other
 hand,  it  was  the intent of  the 1970  law to  prevent the air every-
 where  from  becoming  uniformly dirty  through a "leveling out"  of
 the Nation's air pollution.

     The  EPA regulations seek to  define "significant" in  a
 reasonable  way that  will allow both  for protection of clean
 areas  and for  national  economic  growth.  Any growth that  occurs
will be well planned, orderly and with application of best
 available control technology to  keep the air as  clean as  possible.

     Overall,  the regulations will result in much more stringent
 limitations on pollution than would be the  case  if no such rules
exi sted.


 WILL THIS MEAN THAT  ALL ECONOMIC  GROWTH WILL STOP?

     Not  at all.  The air pollution  limit for a  Class II
 area,  for example, would under normal circumstances permit
 construction there of any of the  major source categories  that
will be  regulated in the program  to prevent significant
 deterioration.

     In a Class  III  area, an aggregation of major  industrial
projects  may be constructed as  long as air quality standards
are not exceeded.

     The  program thus can help  States and local  governments

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and citizens decide not only where growth should  be  prohibited,
but also where growth should be encouraged.

DOES THIS PROGRAM MEAN MORE FEDERAL CONTROL?

     No.  The program gives the States and local  governments
the flexibility and primary responsibility for making decisions
that affect the people they serve.  State and local  people  have
a better understanding of the social,  economic and environ-
mental factors that go into decisions  to reclassify.  State
and local governments can be more responsive to State and  local
needs than any Federal agency.  Moreover, EPA believes that
State and local governments should continue  to exercise the
basic land-use decision-making responsibility.

CAN A CLEAN AREA PROTECT ITSELF?

     That's up to local governments and the  State, mainly.
Even a slight increase in pollution in the air might damage
the economy of a recreational area.  On the  other !iand, an
area facing severe unemployment may welcome  industrial growth
and new job opportunities.   Even in the latter cas  , however,
air quality impact can and  should be minimized.

     EPA believes that most decisions  about  development of
affected areas should not be based only on environmental  factors
For this reason, as long as proper procedures are followed  and
no decision is arbitrary or capricious, EPA  wants the States
or local governments and the people to make  decisions about
whether to reclassify an area to Class I (no development)  or
Class III (whatever development the air quality standard will
allow).


REGIONAL AND NATIONAL EFFECTS OF RECLASSIFICATION

     An example of a "regional" effect would be the downwind
impact of air pollution' from a power plant.   Where  a major
industrial source is planned, the facility must be  situated
so it will not affect air quality in "adjacent" areas--
perhaps up to a distance of 60 miles in the  case of a coal-
fired power plant of 1,000 or more megawatts controlling
emissions to meet new source performance standards.   For
other major sources, and for power plants controlling emissions
beyond new source performance standards, downwind effect
generally will be considerably less — perhaps 6 to 30 miles.
Such variables as the terrain, weather conditions,  and the
size of the source would be determining factors.

     "National" effects might include such elements as the
impact of pollution on food supply and production,  the pre-
servation of sufficient recreation and wilderness land, and
the supply and development of energy resources.

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     After a State's proposed redesignation of an area to
Class I or III is offered for public comment in the Federal
Register, Federal agencies and any citizen would be expected
to make known their views on any national effects of which
they are aware.  Finally, it would be up to the Administrator
of EPA to rule on the proposed request.

WON'T EVERYONE BE TRYING TO SWITCH TO CLASS I OR III?

     EPA believes not.   No large-scale switching of classifications
is expected because Class II--into which all areas now fall--
will  accommodate most moderate,  well planned development while
also  providing substantial safeguards for air quality.  And the
public can be expected  to react  against efforts either to
unreasonably restrain development or to endanger valued areas
that  should be preserved.


January 1976

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