EPA-902/4-78-005
Attainment and Maintenance
of Sulfur Dioxide Standards
       in Puerto Rico
         Final Report
         October 1978

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      ANALYSIS OF SULFUR DIOXIDE

              AIR QUALITY

                  IN

              PUERTO RICO
             Submitted to

 U. S. Environmental Protection Agency
           Region II Offices
            New York, N. Y.

                  AND

Puerto Rico Environmental Quality Board
         Santurce, Puerto Rico
             Submitted by

          Engineering-Science
          7903 Westpark Drive
         McLean, Virginia 22101
             October 1978

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                            TABLE OF CONTENTS
                                                                       Page
CHAPTER I
CHAPTER II
CHAPTER III
CHAPTER IV
INTRODUCTION
BACKGROUND
STUDY YEARS
STUDY AREAS
METHODOLOGY
ORGANIZATION OF REPORT
EMISSION INVENTORIES
POINT SOURCE INVENTORIES
AREA SOURCE INVENTORY
SUMMARY OF EMISSIONS BY SOURCE CATEGORY
DISCUSSION OF RESULTS
MODEL CALIBRATION
ISLAND-WIDE PREDICTIONS
SOURCE CATEGORY CONTRIBUTIONS
INDIVIDUAL STUDY AREA ANSLYSIS
SUMMARY AND CONCLUSIONS
  1-1
  1-1
  1-1
  1-1
  1-3
  1-3
 II-l
 II-l
 II-l
 II-2
III-l
III-l
III-l
III-7
III-7
 IV-1
                             LIST OF TABLES
TABLE 1-1        STUDY  AREAS
TABLE II-l       SUMMARY OF GROWTH FACTORS FOR
                 PUERTO RICO
TABLE II-2       STUDY AREAS
TABLE II-3       MUNICIPALITIES INCLUDED IN THE
                 NORTHEASTERN STUDY AREA
TABLE II-4       MUNICIPALITIES INCLUDED IN THE
                 SOUTHERN STUDY  AREA
                                                       1-3

                                                      II-3
                                                      II-4

                                                      II-5

                                                      II-7

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                       LIST OF TABLES  (CONTINUED)
                                                                       Page
TABLE II-5

TABLE II-6


TABLE II-7

TABLE II-8

TABLE III-l


TABLE III-2

TABLE III-3




TABLE III-4



TABLE III-5




TABLE III-6



TABLE III-7



TABLE III-8
MUNICIPALITIES INCLUDED IN THE
NORTHWESTERN STUDY AREA

SOURCE CATEGORY EMISSION CONTRIBUTIONS
STUDY  AREA: NORTHWESTERN

SOURCE CATEGORY EMISSION CONTRIBUTIONS
STUDY AREA: SOUTHERN
SOURCE CATEGORY EMISSION CONTRIBUTIONS
STUDY  AREA: NORTHEASTERN
COMPARISON OF MEASURED AND PREDICTED
S02 AIR QUALITY

ADDITIONAL S02 CONTINUOUS MONITORING DATA
FOR THE GUAYANILLA AIR BASE
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED
AIR QUALITY AT THE LOCATION OF MAXIMUM
CONCENTRATION
STUDY AREA:  NORTHWESTERN
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED
AIR QUALITY AT THE LOCATION OF MAXIMUM
CONCENTRATION
STUDY AREA: SOUTHERN
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED
AIR QUALITY AT THE LOCATION OF MAXIMUM
CONCENTRATION
STUDY AREA: SOUTHERN
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED
AIR QUALITY AT THE LOCATION OF MAXIMUM
CONCENTRATION
STUDY AREA: SOUTHERN
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED
AIR QUALITY AT THE LOCATION 07 MAXIMUM
CONCENTRATION
STUDY AREA: NORTHEASTERN
MAXIMUM SO,
STUDY AREA*
CONCENTRATIONS IN DESIGNATED
 II-9

 11-12


 11-13

 11-14

III-2


III-6




III-8



III-9



111-10



III-ll



111-12


111-13
                                   ii

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                      TABLE OF CONTENTS (CONTINUED
                             LIST OF FIGURES
                                                                       Page
FIGURE 1-1       STUDY AREAS                                           1-2
FIGURE II-l      PUERTO RICO NORTHEASTERN STUDY AREA                  II-6
FIGURE II-2      PUERTO RICO SOUTHERN STUDY AREA                      II-8
FIGURE II-3      PUERTO RICO NORTHWESTERN STUDY AREA                  11-10
FIGURE III-l     ANNUAL AVERAGE CONCENTRATIONS - BASE YEAR           III-4
FIGURE III-2     ANNUAL AVERAGE CONCENTRATIONS - 1990                III-5
                                   iii

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                                CHAPTER I
                              INTRODUCTION

BACKGROUND
     The recent Clean Air Act Amendments of 1977 called for the participation
of local, state, and Federal air pollution control officials to meet ambient
air quality standards as expeditiously as possible, and to establish plans
for the coming years to deal with the maintenance of clean air levels.   As
a result of this Contressional mandate, Engineering-Science (ES) has been
engaged by the U. S. Environmental Protection Agency (EPA) to assist the
Puerto Rico Environmental Quality Board (EQB) in conducting an engineering
analysis of sulfur dioxide levels in Puerto Rico.  This study is being con-
ducted concurrently with another analysis underway for particulate matter.

STUDY YEARS

     This study is concerned with the predictions of sulfur dioxide air quality
levels in Puerto Rico for the years 1976 and 1990.  Emission inventories for the
base year for both point and area sources had been compiled in previous studies
completed by ES.  This data base was recently updated using information provided
by EQB in October 1977.  Growth estimates for the projection year were obtained
from industry and government officials and represent the best estimates of future
industrial production and domestic activity on the island.

STUDY AREAS

     The areas  analyzed in  this study were determined previously by EPA and ES
as having  the potential for exceeding  the air quality standards for sulfur dioxide.
These  areas are listed below and appear  in Figure  1-1.
                                     1-1

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STUDY AREAS
                                                          cr>
                                                          73

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                                TABLE 1-1
                               STUDY AREAS

     Aquadilla                             Guayanilla-Penuelas
     Arecibo-Braceloneta                   Lares-Utuado-Adj untas
     Dorado                                Ponce
     Guanica                               San Juan
     Guayama                               Yabucoa

METHODOLOGY
     EPA's dispersion model, AQDM, was used together with emission and
meteorological data to predict sulfur dioxide levels in each of the study
areas, including most of the SO- monitoring stations presently operated by
EQB.  Concentrations were predicted for both the base case and 1990.  Source
category contributions  to air quality at the locations of maximum concen-
tration were determined through an analysis of the AQDM contribution file.
This will help in the development of S0_ control strategies by indicating what
type sources contribute the most to SO- levels.  Concentration isopleths were
drawn from data obtained using a grid of receptors over most of the island.

ORGANIZATION OF REPORT

     Chapter I has dealt with the presentation of background information and
the introduction to the analysis.  Chapter II concerns the development of the
emission inventories and Chapter III presents the discussion of results.  A
report summary is provided in Chapter IV.
     All tasks involved in the completion of this study were performed by the
staff of Engineering-Science, McLean, Virginia.  The report is a scientific
and impartial evaluation of SO. air quality in Puerto Rico and does not
reflect or advocate any particular position of view by the authors.
  The  term 'source  category contributions' refers to the air quality level
  directly associated with a specific category of emission sources.  Such
  information  is  extremely valuable in developing strategies to reduce emissions.
                                  1-3

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                               CHAPTER II
                          EMISSION INVENTORIES

POINT  SOURCE  INVENTORIES
     The point source inventory used in this analysis was developed in
October 1977  and was the result of a series of updates that were undertaken
by EQB as part of their routine file maintenance procedure.1  The completed
file was judged by EQB to reflect operating conditions existing in 1976, and
represent the most current SO- emission inventory.
     Basically the point source file consists of some 5,000 computerized records,
forming a standard file on more than 600 plants or companies, with individual
process description and stack data for over 1,500 emission points.  The infor-
mation was arranged in EIS/P&R format and was easily processed using standard
CDHS programs.
     Important SO- emission categories in the point source file were steam
boilers and petroleum process heaters.

AREA SOURCE INVENTORY
     The inventory consisted of information on a municipality level related
to emission categories such as commercial/institutional and light industrial
fuel use, open burning and traffic.  Some municipalities such as San Juan,
Ponce, and Mayaguez had been sub-divided to provide an added level of detail.
                                                               2
The information had been compiled by ES under a previous study.
     The S0_ emission category which had the highest emission in the area
source file was fuel combustion for light industrial processes.
  EQB uses the EIS/P&R computer data handling system to maintain data on
  emissions and plant operating characteristics.
2
  Puerto Rico Air Quality Maintenance Planning and Analysis,  Base Year
  Evaluation and Projections,  Engineering-Science,  1976.
                                     II-l

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SUMMARY OF EMISSIONS BY SOURCE CATEGORY

     Individual points in EIS/P&R inventories are characterized by an
eight-digit Source Classification Code (SCC) assigned by agency personnel
when source information is entered into the computer file.  Each SCC re-
presents a specific function within a broad source category.  Classification
of sources by their SCC enabled several source categories to be analyzed
with regard to emissions in the base case and for the study year 1990.
     Projection of emissions from the base case to 1990 were handled by
assuming that all growth occurred in place.  Growth factors obtained from
industry personnel and questionnaires, or government forecasts were then
applied to base emissions.
     Specific growth information was available from three major industries
on the island: sugar processing, asphalt batching, and power generation.
The indication from asphalt and sugar companies was that there would be no
growth in total output in terms of emissions over the period.  The power
company plans to satisfy increasing demand, projected to 1990 to be about
180% of 1976 levels, by increasing output from existing stations, at least
until 1988.  Specific factors were also available from mineral processing
industries (rock handling, storing) and beverage manufacturers.  The selection
of a growth factor for the asphalt, pharmaceutical, and food processing
industries was based on Island-Wide Population Projections.   For all other
sources a factor of 4.5% per year increase was used reflecting the growth
                                                2
in Gross National Product expected through 1985.   Table II-l presents the
factors used to project the 1976 emissions to 1990 levels.
     The 1990 scenario must really be considered a worst case analysis.  The
scenario does not consider the effect of an offset policy, nor does it con-
sider the fact that some of the new emissions will likely be spread out at
   Puerto Rico Planning Board, Social Planning Bureau.
2
   U. S. Industrial Outlook, 1976, with Projections to 1985, U. S. Dept. of
   Commerce, Domestic and International Business Administration, Bureau of
   Domestic Commerce, January 1976.
                                  II-2

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TABLE II-l
SUMMARY OF GROWTH FACTORS FOR PUERTO RICO

FACTORS FOR PERIOD
2-DIGIT SIC GROUP 1*76 TO 1990
20







21
22
23
24
25
26
27
23

29


30
31
32





33
34
35
36
37
38
39
4911
Food - kindred products
2051 Bread
2052 Cookies Crackers
2061 Cane Sugar
2062 Cane Sugar Refining
2082 Male Liquors
2085 Distilled Liquors
2095 Roasted Coffee
Tobacco
Textile Mill Products
Apparel and finished products
Lumber and vood products
Furniture
Paper and allied products
Printing, publishing etc.
Chemicals and allied products
2834 Pharaaceucical Preparations
Petroleum refining
2951. Paving mixtures and blocks
2952 Asphalt felts and coatings
Rubber and miscellaneous plastic products
Leather and leather products
Stone, clay and glass products
3271 Concrete block and brick
3272 Concrete products
3273 Ready-mixed concrete
3281 Cut stone
3295 Minerals and earths
Primary metals
Fabricated metal products except machinery
Fabricated metal products machinery
Electrical machinery equipment
Transportation equipment
Professional scientific instruments
Miscellaneous manufacturing (all others)
Electric Companies
1.94
1.25
1.25
1.00
1.00
1.84
1.84
1.25
1.94
1.94
1.94
1.94
1.94
1.94
1.94
1.94
1.25
1.94
1.00
1.25
1.94
1.94
1.94
1.15
1.15
1.15
1.15
1.15
1.94
1.94
1.94
1.94
1.94
1.94
1.94
1.80
      II-3

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new plant sites.  The scenario does not account for the fact that these new
emissions may have to meet new source performance standards if a new unit is
built to accommodate the increase in demand for a product.  For the 1990 scenario
we have assigned all new emissions to existing emission sites, which will
tend to make predicted concentrations higher than actually expected.
     In the point source master file there were about 365 points with emis-
sions of sulfur dioxide greater than, or equal to one ton per year.  Total
island-wide point source emissions of particulate matter were estimated at
about 290,000 tons per year.  Because of the preponderance of small sources
only those point sources emitting over 5 tons per year were modeled in order to
avoid costly dispersion model computer runs.  The remaining sources, numbering
about 80 and representing about 162 tons per year, were combined with the area
source emissions from the nearest municipality.  Furthermore, three separate areas
of the island were analyzed individually.  For each maintenance area, the cor-
responding emission inventory and meteorological data were used.  The study
areas considered were the geographic portions of the island listed in Table
II-2 and illustrated in Figures II-l through II-3; some degree of overlap
occurs.  Tables II-3 through II-5 give the municipalities included in each
study area.

                               TABLE II-2
                               STUDY AREAS
  GEO-LOCATIONS
 RECORDING SITE FOR
METEOROLOGICAL DATA
      NUMBER OF
POINT SOURCES MODELED
 OVER 5 TONS PER DAY
  NUMBER OF
 SURROUNDING
MUNICIPALITIES
    MODELED
Northeast Quarter
Northwest Quarter
Southern Half
   Isla Verde
   Ramey AFB
   Santa Isabel
         126
          61
         148
      40
      33
       55
                                  II-4

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TABLE II-3

SAROAD
CODE
0140
0320
0360
0400
0480
0517
0540
0580
0640
0680
0720
0800
0840
0880
0940
0960
1140
1180
MUNICIPALITIES
NORTHEASTERN

NAME
Aguas Buenas
Barcelona ta
Barranquitas
Bayamon
Caguas
Canovanas
Carolina
Catano
Ceiba
dales
Cidra
Comeria
Corozal
Dorado
Faj ardo
Florida
Guaynabo
Gurabo
INCLUDED IN
STUDY AREA

SAROAD
CODE
1280
1420
1520
1560
1580
1620
1740
1780
1820
1860
2020
2160
2200
2300
2320
2340
2420
2460
THE

NAME
Humacao
Juncos
Las Piedras
Loiza
Luquillo
Manati
Morovis
Naguabo
Naran j ito
Orocovis
Rio Grande
San Juan
San Lorenzo
Toa Alta
Toa Baja
Trujillo Alto
Vega Alta
Vega Baja
     II-5

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      PUERTO RICO
NORTHEASTERN STUDY AREA
                                            22B     244
                                                                en
                                                                70

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           TABLE II-4
MUNICIPALITIES INCLUDED IN THE
      SOUTHERN STUDY AREA
SARD AD
CODE
0040
0180
0280
0360
0440
0620
0720
0760
1020
1060
1100
1240
1280
1340
1380
1440
NAME
Ad juntas
Aibonito
Arroyo
Barranquitas
Cabo Rojo
Cayey
Cidra
Coamo
Guanica
Guayama
Guayanilla
Hormlgueros
Humacao
Jayuya
Juana Diaz
La j as
SAROAD
CODE
1520
1640
1660
1700
1880
1900
1940
2060
2080
2120
2200
2280
2500
2540
2580

NAME
. Las Piedras
Maricao
Maunabo
Mayaguez
Patillas
Penuelas
Ponce
Sab an a Grande
Salinas
San German
San Lorenzo
Santa Isabel
Villalba
Yabucoa
Yuaco

           II-7

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                                                PUERTO  RICO

                                            SOUTHERN STUDY AREA
M
I
oo
                                                                                        220      244
                                                                                                            £75
                                                                                                            i
                                                                                                            ro

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TABLE II-5

SAROAD
CODE
0040
0080
0120
0200
0240
0320
0500
0680
0840
0960
1220
1240
1320
1340
MUNICIPALITIES
NORTHWESTERN

NAME
Adjuntas
Aguada
Aguadilla
Anasco
Arecibo
Barceloneta
Camuy
dales
Corozal
Florida
Hatillo
Hormigueros
Isabela
Jayuya
INCLUDED IN
STUDY AREA

SAROAD
CODE
1480
1500
1620
1640
1700
1720
1740
1860
1960
1980
2240
2380
2420
2460
THE

NAME
Lares
Las Marias
Manati
Maricao
Mayaguez
Moca
Morovis
Orocovis
Quebradillas
Rincon
San Sebastian
Utuado
Vega Alta
Vega Baja
   II-9

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                                          PUERTO  RICO

                                    NORTHWESTERN  STUDY AREA
10 —	
                                                                               220      244
                                                                                                  CD
                                                                                                  70
                                                                                                  m

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     The emissions for the three separate study areas are summarized in
Tables II-6 through II-8  by major emission source category.   For point
sources, the highest emissions were observed from external combustion boilers.
                                  11-11

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                      TABLE  II-6
       SOURCE CATEGORY EMISSION.CONTRIBUTIONS
             STUDY AREA:  NORTHWESTERN
                              CONTRIBUTIONS  - TONS/DAY
    SOURCE CATEGORY              BASE           1990
Area Sources
Boilers
Turbines
Petroleum Process Heaters
Process and Other Heaters
Incineration
12.9
18.7
13.1
-
1.6
0.8
23.1
29.0
23.5
-
2.2
1.0
TOTAL                            47.1           78.8
                        11-12

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                      TABLE II-7

       SOURCE CATEGORY EMISSION CONTRIBUTIONS
               STUDY AREA:  SOUTHERN
    SOURCE CATEGORY
CONTRIBUTIONS - TONS/DAY
   BASE          1990
Area Sources                     25.7
Boilers                         339.3
Turbines                         31.3
Petroleum Process Heaters        72.3
Process and Other Heaters         4.5
Incineration                      0.2
                 46.3
                613.4
                 56.8
                140.3
                  6.9
                  0.3
TOTAL
 473.3
864.0
                      11-13

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                     TABLE II-8
       SOURCE CATEGORY EMISSION CONTRIBUTIONS
              STUDY AREA:  NORTHEASTERN
    SOURCE CATEGORY
CONTRIBUTIONS - TONS/DAY
   BASE          1990
Area Sources                     37.8
Boilers                         246.0
Turbines                         16.5
Petroleum Process Heaters         7.0
Process and Other Heaters        29.0
Incineration                      ^ • ?
                 68.1
                439.4
                 29.6
                 13.6
                 55.3
                  2.8
TOTAL
 338.0
608.8
                      11-14

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                               CHAPTER III
                          DISCUSSION OF RESULTS

MODEL CALIBRATION
     Sulfur dioxide monitoring data for 1976 were available for 9 sites in
Puerto Rico.  One of the first steps in the analysis, after emission inventory
preparation, was to use EPA's Air Quality Display Model (AQDM) to estimate
the concentrations of SO. at these sites for comparison with measured data.
The comparison is used to validate the model and also develop a calibration
factor.  In this case the comparison resulted in a gross difference between
the predicted value and the measured value.  At most sites, predicted mean con-
centrations were 3 times the measured concentration.  Because of this, ES did
not use a calibration factor for adjustment of predicted concentrations for any
of the study areas.  All monitoring used gas bubblers which have been known
to be unreliable at times, yielding ambient concentration values lower than
those from continuous monitoring units.   The comparison between measured and
predicted concentration appears in Table III-l.  The Puerto Rico and Federal
Air quality standards for S02 are:
                                      3
     o  Primary Standard       80 yg/m  annual arithmetic mean
                                      3                       1
     o  Secondary Standard     60 yg/m  annual arithmetic mean

ISLAND-WIDE PREDICTIONS

     Emission and meteorological  data files were developed for three separate
geographic areas of the island.   This approach was justified  since the
island has distinct characteristics of rugged terrain at its  center, affect-
ing dispersion, and since meteorological data were available  from three loca-
                                             2
tions.  In a previous  report published by ES,  an analysis of the variations
in meteorological data was made between the San Juan, Ponce,  and Ramey
sites.  Specific data  concerning  emissions have been discussed in Chapter II.
   Suggested guideline.
 2
   Puerto Rico Air Quality  Maintenance, Planning  and Analysis, Base Year
   Evaluation and Projections,  Engineering-Science, 1976.
                                  III-l

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                      TABLE III-l


               COMPARISON OF MEASURED AND

                PREDICTED S02 AIR QUALITY
MONITORING SITE
San Juan
Bayamon
Catano - Las Vegas
Guaynabo - Ft. Buchanan
Toa Baja
Ponce
Guayanilla - Plaza
Guananilla - Magas Arriba
Penuelas
CONCENTRATIONS
MEASUREDa
7
8
8
9
7
6
7
7
7
- yg/m3
PREDICTED13
23
53
71
48
67
15
26
33
9
a
  S09 was measured using the gas bubbler
•i    £•

  The model predicted concentration with no calibration

  factors applied, i.e. slope = 1.0 and background =0.0 yg/m .
                         III-2

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     Table III-2 summarizes some additional S0_ data collected for the
January through August 1977 period.  These measurements were from continuous
monitoring used around a large oil fuel power plant.  The higher concentration
observed occurred at monitors which were sufficiently above the plant elevation.
                                                                         3
The predicted concentration for this area ranged from about 50 to 70 yg/m ,
annual basis.  These few data points tend to validate the use of a dispersion
model like AQDM to predict S02 levels throughout the Commonwealth.
     EPA's AQDM was used to predict ambient S0» concentration over the three
portions of the island, covering all study areas.   In general,  a four-by-four
kilometer grid spacing was used for receptor locations.  A one-by-one grid
spacing was used in Catano.  Concentration isopleths were then drawn using
the concentrations predicted for each grid point.   Two cases were analyzed:
actual operating conditions for the base year 1976, and projected operating
conditions for 1990.  For the 1990 case, emissions were assumed to grow
unconstrained at existing emission sites; new source location were not con-
sidered.  The isopleths for the base year and 1990 appear in Figures III-l
and III-2.
     Centers of industrial activity on the island were apparent with the
coincidence of high SC-  concentrations.  In general, these were the Catano,
Guayanilla, Guayama, and Yabucoa areas.  Other regions of the island showed
somewhat less activity in emissions and ambient S0_ levels.  The highest
concentration on the island was predicted to occur in Catano with a value
          3                                                                  3
of 92 yg/m  annual basis.  This value exceeds the primary standard of 80 pg/m .
No other study areas were found to exceed the primary standard.  By 1980,
however, it is expected that three study areas will exceed the primary standard.
Even considering our 1990 analysis as "worst case" situation, it appears that
control strategies will have to be implemented to reduce S0» emissions as the
primary standard will be exceeded.  New amendments to the EQB's Article VI
regulation covering sulfur dioxide emission from virtually every stack on the
island can be used to "readjust" the allowable S0_ emission such that air quality
standards will never be exceeded.  However, this approach will require an accu-
rate emission inventory on an annual basis for not only point sources but area
sources as well.
     Concentrations in the base case are above the standard in Catano, and close
to the secondary standard in some other areas.  With any industrial growth at

                                     III-3

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                                                                                    FIGURE III-l
ANNUAL AVERAGE SO. CONCENTRATIONS  -g/m ARITHMETIC MEAN
                         BASE  YEAR
                                                                                     244

                                                                               ENGINEERING-SCIENCE

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                                                                                                                          FIGURE III-2


                                  AiMUAL  AVERAGE SO:  CONCENTRATIONS - ug/m  ARITHMETIC MEAN
                                                               1990
10
                                                                                          >96
                                                                                                     212
                                                                                                                226
                                                                                                                          2*4
                                                        uTM(nm)
                                                                                                                    ENGINEERING-SCIENCE

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                               TABLE III-2
ADDITIONAL SO,,
• • 	 ' •'" *.
THE
CONTINUOUS MONITORING DATA
FOR
GUAYANILLA AIR BASE3




Mario Mercada Hill
Mario Mercada Castle
Corco
Guayanilla Plaza
(Port Authority Bldg.)
Magas Arriba
(Eugenia M. Hastos School)
Magas Abajo
Stella Hill
Guayanilla
(Government Center)
S02
JAN-AUGUST
1977
49
50
84
14
11
21
24
6
CONCENTRATION

3-hour Max.
630
629
1072
118
147
233
270
94
(yg/m )

24-hour Max.
181
236
307
55
84
63
79
37
The predicted S02 concentration for this area ranged from about
50 - 70 pg/rn-^, annual basis.  No micro scale modeling was completed for
these monitors.
                                   III-6

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all, concentrations will continue to increase unless emissions are reduced at
the same time.  One method that can be used to accommodate growth is through
the emission offset policy, which requires that new sources reduce emissions
from an existing plant by an amount equal to or greater than the amount they
intend to add.

SOURCE CATEGORY CONTRIBUTIONS
     If control strategies are to be effective, they must deal with the emission
sources of greatest importance.  For each of the maximum concentration receptors
indicated on the isopleth map of Figure III-l, the contributions to the pre-
dicted concentration have been tabulated by source category.  Contributions
were also determined for the same receptors for the 1990 case.  Tables III-3
through III-7 present the contributions from area sources, boilers, turbines,
manufacturing processes, process heaters, and incinerators using auxiliary fuel.
It appears that the categories with the greatest contribution are external com-
bustion boilers and process heaters.  These categories account for more than
50% of the total predicted air quality level at each of the maximum sites.

INDIVIDUAL STUDY AREA ANALYSIS
     Ambient concentrations were predicted for the 10 study areas of interest
listed in Chapter I.  Maximum concentrations in each area are presented in
Table III-8.  Of the ten, only one indicated concentrations exceeding the
primary standard while all others showed SO,, levels within the secondary
standard.  For the 1990 conditions analyzed, five areas are expected to exceed
the secondary standard, while three show average values exceeding the primary
standard.  Certainly EQB must plan ahead in order that air quality standards
will be maintained.  The Clean Air Act requires that the states revise their
plans to show maintenance of the standards.   This must be accomplished through
emission limitations.  Probably the most effective means of insuring emission
reductions over the long term will be the application of Article VI or an
emission offset policy.
                                     III-7

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                       TABLE III-3
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED AIR QUALITY
       AT THE LOCATION OF MAXIMUM CONCENTRATION
STUDY AREA:  Northwestern
MUNICIPALITY:  Arecibo
UTM LOCATION:  136.0  66.0

SOURCE CATEGORY
Area Sources
Boilers
Turbines
Petroleum Process Heaters
Process and Other Heaters
Incineration
TOTAL
CONTRIBUTIONS
BASE
3.1
18.0
1.6
0.0
8.5
5.2
36.4
- Ug/m3
1990
5.6
25.6
0.5
0.0
9.4
6.5
47.6
                        III-8

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                       TABLE  II1-4
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED AIR QUALITY
       AT THE LOCATION OF MAXIMUM CONCENTRATION   .
STUDY AREA:  Southern
MUNICIPALITY:  Guayanilla
UTM LOCATION:  116.0  22.0

SOURCE CATEGORY
Area Sources
Boilers
Turbines
Petroleum Process Heaters
Process and Other Heaters
Incineration
TOTAL
CONTRIBUTIONS
BASE
9.7
23.4
0.6
5.1
0.5
0.0
39.3
- yg/m3
1990
17.4
43.6
1.0
9.8
0.9
0.0
72.7
                        III-9

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                       TABLE III-5
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED AIR QUALITY
       AT THE LOCATION OF MAXIMUM CONCENTRATION
STUDY AREA:   Southern
MUNICIPALITY:  Guayama
UTM LOCATION:  180.0  14.0

SOURCE CATEGORY
Area Sources
Boilers
Turbines
Petroleum Process Heaters
Process and Other Heaters
Incineration
TOTAL
CONTRIBUTIONS
BASE
5.6
8.6
0.1
20.0
0.1
0.0
34.4
- Ug/m3
1990
10.0
16.5
0.2
38.9
0.1
0.0
65.7
                       111-10

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                      TABLE II1-6
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED AIR QUALITY
       AT THE LOCATION OF MAXIMUM CONCENTRATION
STUDY AREA:  Southern
MUNICIPALITY:  Yabucoa
UTM LOCATION:  212.0  22..0

SOURCE CATEGORY
Area Sources
Boilers
Turbines
Petroleum Process Heaters
Process and Other Heaters
Incineration
TOTAL
CONTRIBUTIONS
BASE
2.2
0.4
0.0
41.5
0.8
0.0
44.9
- yg/m3
1990
4.0
0.7
0.1
80.5
1.6
0.0
86.9
                        III-ll

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                      TABLE III-7
SOURCE CATEGORY CONTRIBUTIONS TO PREDICTED AIR QUALITY
       AT THE LOCATION OF MAXIMUM CONCENTRATION
STUDY AREA:  Northeastern
MUNICIPALITY:  Catano
UTM LOCATION:  183.0   65.0

SOURCE CATEGORY
Area Sources
Boilers
Turbines
Petroleum Process Heaters
Process and Other Heaters
Incineration
TOTAL
CONTRIBUTIONS
BASE
18.0
69.1
0.2
0.8
3.5
0.9
92.5
- yg/m3
1990
32.2
132.0
0.3
1.4
6.8
1.8
174.5
                        111-12

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                         TABLE  III-8
                 MAXIMUM S02 CONCENTRATIONS
                 IN DESIGNATED STUDY AREAS
STUDY AREA
Aguadilla
Arecibo - Barceloneta
Lares - Utuado - Adjuntas
Guanica
Guayanilla
Ponce
Guayama
Yabucoa
Dorado
San Juan (Catano)
MAXIMUM CONCENTRATIONS
BASE YEAR
5
38
5
21
40
19
34
46
49
*
92
- Ug/m3
1990
10
48
10
39
75**
33
66**
87*
89*
*
174
*
**
Exceeds both the primary and secondary standards
Exceeds the secondary standard.
                           111-13

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                                 CHAPTER IV
                           SUMMARY AND CONCLUSIONS

     1.  Engineering-Science used the EPA's AQDM to estimate existing
ambient S0_ levels in 10 study areas of Puerto Rico.
     2.  Due to the unsuitability of air monitoring data, the AQDM could
not be validated and no calibration factor was used to adjust predicted
concentrations.
     3.  Groundlevel concentrations exceeding the primary SO- standard of
       3
80 pg/m  were predicted in only one study area, Catano.

      4.   Emissions were projected  to  1990,  assuming unconstrained in place
    growth.   Growth factors were  available  from industry  and  government.
      5.   Concentrations were  predicted  for the 1990 case in  the same 10  study
 areas.   The  results  indicated that three study areas would be exceeding
 the primary  standard and  that two  others would exceed  the suggested secondary
                              3
 standard guideline of 60  yg/m .
     6.   Contributions to maximum  concentrations were  presented to identify
source categories most responsible  for  the high concentrations.  These contri-
bution tables should be used  to  develop cost effective control strategies.
     7.   Suggested control strategies are a stricter limit for sulfur in fuel
in  those  areas where standards have the potential to be  exceeded by use of
EQB's Article VI regulation on SO  •emission.
     8.  An emission offset policy could also be used  to prevent further
degradation of the ambient air quality.
                                    IV-1

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