HomeMy WebLinkAboutSP 144B; SDG&E Wastewater Facility; Specific Plan (SP) (7)CITY OF CARLSBAD
FINAL EIR #205
SINGLE STACK MODIFICATION PROJECT FOR ENCINA POWER PLANT
PLANNING COMMISSION RECOMMENDATION TO CITY COUNCIL
Certification. November 13. 1973
. i . *
CITY COUNCIL ACTION:
Certification, November 20, 1973
REASONS FOR CERTIFICATION:
The final EIR adequately expresses the environmental impacts of the
proposed project. Alternatives to the project are:
a) More impacting in terms of their environmental
consequences; or
b) Not technically feasible. In this instance the no project
alternative is not acceptable, since it would place the
project in violation of State Air Quality Standards.
TABLE OF CONTENTS
Summary and Analysis ------------- — — -- - 1
Prepared by City of Carlsbad Planning Department
Letter from David Parkinson, Westec Services, -------- 4
Comparing the Stack Modification EIR and CPUC
Encina Unit #5 EIR.
List of Reviewing Agencies ----------------- 6
Response from Reviewing Agencies -------------- 7
Minutes from Public Hearings- ---------------- 8
, i ....
Draft EIR-- - - .1
Prepared by Westec Services under contract to the
City of Carlsbad
SUMMARY AND ANALYSIS
Prepared by
Carlsbad Planning Department
1) Scope of E.I.R.: Summary:
The E.I.R. deals with SDG&E's decision to opt for a single 400 ft.
MSL stack with the addition of a fifth generating unit to the Encina
Plant. The potential impact, therefore, relates solely to the re-
moval of the existing stacks at 190 feet MSL and the ..construction ;
of a single 400 ft. stack. The City has previously considered the
expansion of the plant facility to include the fifth generating unit,
and therefore, this matter is not considered directly by the Draft
E.I.R.
In terms of important issues, staff believes that the aesthetic im-
pact and the air pollution potential over a substantial area are the
major concerns of the proposed stack.
2) Environmental Setting:
The new stack foundation will be laid on the presently unused
portion of the site, d'irectly to"the east of the existing power
plant. The area of visual impact of the 400 ft. stack would be
approximately 4 miles in all directions. Population within tho
visual impact area would be about 28,000 persons vs. 12,000 persons
for the existing structure.
The power plant is about 3 miles from Palomar Airport and in its
existing form, does not constitute an air traffic obstruction,
according to F.A.A. regulations. The single stack modification
would require special lighting according to F.A.A. standards, but
would not be a hazard to air navigation.
A study of local air quality conducted by Stanford Research Institute,
indicated that existing air quality conditions associated with the
plant's operation are satisfactory, but that additional generating
units could contribute to ground level concentration in excess of
State Standards, with the addition of a fifth stack.
3) Environmental Impacts:
a) Air Quality: The 400 ft. stack does not effect the production
of pollutants by the plant, but rather, allows dispersion of
pollutants in order to preclude ground level concentrations of
S02 from exceeding California 25 hr. S02 standards. The 400 ft.
stack will diminish the adverse impacts on air quality by:
i. Reducing the "aerodynamic downwash of emissions from the
plant" and,
ii. Reducing the potential for downwind odor problems from the
sulfur dioxide.
-1-
b) Aesthetics: A public opinion survey was conducted by Central
Surveys in order to evaluate the public's reaction to the aesthe-
tics of the proposed stack modification. When shown a photograph
of the plant in its present stack, 72% of the sample said that
they preferred the appearance of the proposed stack modification.
However, when questioned whether they would favor the construction
of a single stack, only 33% replied yes. What this seems to
indicate is that although the single stack is preferable to the
plant in its present state, it does not represent a positive
aesthetic value when considered on the basis of no stack. The
increase of the impact area from some 9 sq. miles to some 34
sq. miles is a substantial effect.
c) Public Safety: No negative impacts on public safety are in-
dicated. The draft E.I.R. contends that the 400 ft. stack will
be a navigational aid for both air traffic and ocean-going vessels.
4) Mitigation Measures: The following measures are planned to mitigate
the adverse aesthetic affect of the proposed stack modification:
a) An 18 ft. facade will be built along the top-of the building
to hide duct work and refine the irregular contours of the
building.
b) A daytime strobe.light will, eliminate the need for a checkered
pattern aircraft warning on the stack.
c) Landscaping along 1-5 and Carlsbad Blvd will help provide some
visual relief from the structure.
5) Alternatives: The alternatives to the single 400 ft stack, are briefly
summarized and evaluated here. The draft E.I.R. does substantially
elaborate in this area, and in addition is attached a further des-
cription of various alternatives.
a) Fifth stack for Unit No. 5 - Results of the study conducted
indicate that a fifth stack would result in ground-level
concentrations in excess of the State Air Resources Board
standards.
b) Use of natural gas (to reduce S02Emissions) - Use of natural
gas would eliminate S02 emissions. However, because of the
limited availability of natural gas and an increasing demand
for higher priority uses (particularly residential con-
sumption), availability of natural gas for power plant use
has been virtually eliminated.
c) Very low sulfur content fuel- SDG&E plans to use lew sulfer
content (less than 0.5%) fuel in all of its generating units.
An assured supply of 0.3% sulfur content fuel, according to SDG&E
is not available. Even so, use of 0.3% sulfur content fuel would
still require "extensive" stack modification in order to meet
ambient air quality standards
-2-
d) S02 Scrubber Systems- Systems for removal of S02 from flue
gasses prior to emission are still in the experimental/proto-
type phases of development. The two main prohibitive aspects
of a S02 removal facility are cost ($36 million as opposed to
$4 million for the proposed modification) and size (such a
facility would be "quite large and difficult to locate on the
present site").
e) Plume Dispersion- Three alternatives for plume dispersion were
considered:
1) Five stacks could be used at 290 ft. (maximum height for
roof mounted stacks) - Even if the stacks were nozzled to
increase discharge velocity, this alternative would, in all
likelihood, contribute to unacceptable ground-level S02
concentrations.
2) The height of existing units 1, 2, and 3 could be increased
by 100 ft. and flue gasses from units 4 and 5 could be
discharged through a single 290 ft. stack - Again, this alter-
native does not achieve the critical height necessary for S02
dispersion.
3) A single 400 ft stack - This alternative was chosen by SDG&E
as the minimal height for plume dispersion which would not
cause the State 24 hour S02 standard to be exceeded.
6) Acceptability of the Draft EIR: It is not inappropriate in evaluating
the EIR for the SDG&E Encina Plant Stack Modification Proposal, to
consider some of the broader long-range environmental concerns. The
cost benefit analysis of the proposed stack modification is in the
broadest sense, to weigh the costs of a negative visual impact and
increased emissions against the benefits of more effective pollution
dispersion and increased generating capacity. The proposed stack
modification is by no means environmentally innocuous. Yet, within
the scope of presently feasible alternatives, it is the optimum
solution for handling the increased emissions which will accompany
the 5th generating unit.
It is important to realize that given the uncertainty concerning de-
mands and fuel availability, and the possibility of environmentally
preferable alternatives in the future, such a solution should not
be static. Environmental sensitivity involves a continuing re-evalu-
ation of environmental, social and economic factors. Accordingly, the
City has proposed that the EIR be supplemented in five years, as new
technologies develop.
-3-
WESTEC Services, Inc. I 1520 State Street, San Diego, California 92112 / (714) 233-7572
73-339
October 31, 1973
Mr. Donald Agatep
Planning Director
City of Carlsbad
1200 Elm Avenue
Carlsbad, California 92008
CITY OF CARLSBAD
P'a""'ng Department
Subject: Draft Environmental Impact Report for San Diego Gas
and Electric Company Encina Plant Single Stack
Modification Project
Dear Mr. Agatep:
Subject Environmental Impact Report was completed by WESTEC
Services, Inc. and delivered to the City of Carlsbad on October 5,
1973. Within the sane time frame the State of California Public
Utilities Commission Draft Environmental Impact Report for the
SDG§E Encina Plant Unit 5 application was published. Aspects of
this latter report deal with the impact of the proposed Encina
Plant 400 foot single stack. We have reviewed the CPUC's Encina 5
report in detail to determine the cross correlation between the in-
formation provided. With regard to the proposed 400 foot single
stack, the following is a summary of the contents of the CPUC's
report as compared with the draft report which we prepared:
1. The data provided are in substance compatible and in
agreement.
2. The CPUC report did not provide drawings or schematics
of the 400 foot stack nor a description of its per-
tinent engineering characteristics. The WESTEC Services
report provided this.
3. With regard to aesthetics, WESTEC Services' report was
substantially more complete in dealing with the impacts.
The CPUC report, while providing information concerning
the aesthetic appearance, dealt only briefly with the
impacts.
-4-
Mr. Donald Agatep
October 31, 1973
Page 2
4. The air quality issues of the Encina Plant were addressed
in much greater detail in the CPUC report. The CPUC
draft EIR included a report on the meteorological field
work and a description of air pollutant simulation tech-
niques used to predict the air quality impacts. These
data were not included in our report but were referenced
within the ambient air quality study provided as
Appendix B. -
5. More detailed geologic data and impact assessments are
provided in the CPUC report although the essence of this
information is summarized in WESTEC Services' report.
6. The WESTEC Services' report explored the alternative
approaches to the 400 foot stack. The CPUC report addressed
the same alternatives but provided additional information
concerning methods of SC^ control.
7. The CPUC report addressed alternative methods of power
generation to; meet the "needs of SDG^E's customers. By
contractual agreement these issues were not included as
a part of our scope of work.
The foregoing represents our best judgment with regard to a
summary comparison of the two reports. Please contact me if you
should have any additional questions.
Very truly yours,
David L. Parkinson
President
DLP:jlr
LIST OF REVIEWING AGENCIES
STATE OF CALIFORNIA DEPT. OF TRANSPORTATION
COUNTY OF SAN DIEGO PARKS S RECREATION DEPT.
INTERGOVERNMENTAL REGIONAL ENVIRONMENTAL MANAGEMENT
COMPREHENSIVE PLANNING ORGANIZATION.
DEPT. OF PUBLIC HEALTH, COUNTY OF SAN DIEGO
COUNTY OF SAN DIEGO AIR POLLUTION CONTROL DISTRICT
SAN DIEGO COAST REGIONAL COMMISSION
PHIL STANBRO
CITY OF CARLSBAD ENGINEERING DEPT.
TERRAMAR ASSOCIATION
COMMUNITY INVOLVEMENT COMMITTEE
; CITY LIBRARY
-6-
\JTATE OF CALIFORNIA—BUSINESS AND TRANSPORTATION AGENCY " RONALD REAGAN, Governor
DEPARTMENT OF TRANSPORTATION
DISTRICT 11, P.O.BOX 81406, SAN DIEGO 92138
November 2, 1973
Mr. Paul Ao Williams
City of Carlsbad
Planning Department
1200 Elm Avenue
Carlsbad, CA 92008
Dear Mr0 Williams:
We are returning under separate cover your Draft
Environmental Impact Report for "San Diego Gas and
Electric Encino Plant" as requested.
Transportation District 11 has no comment in our area of
expertise or jurisdiction. •
Very truly yours,
J0 Dekema
District Director
of Transportation
RECEIVED
James T. Cheshire
District Environmentalist ' Mr,y .-> ~., _,
' • \J \ \i i \.- -.
CITY OF CARLSBAD
Planning Department
DP:de
cc: Sep.Cov.
JOG,
JTC
'OF ' CARLSBAD
November 13, 1973
-3-^ vp
(b) CASE NOS: EIS#205, and SPECIFIC PLAN-144 - SAN DIEGO
GAS AND ELECTRIC COMPANY: Request for acceptance of a
Final Environmental Impact Report and adoption of a
Specffic Plan amendment, to permit the construction of a
400 ft. single-stack to replace the four (4) existing
stacks, on property generally consisting of 680 acres
located east of the Pacific Ocean and southerly of the
north shore of the Agua Hedionda Lagoon, presently
zoned P-U (Public Utility).
Planning Director Agatep gave the staff report for
this project and the background covering the EIR in-
formation.
No questions of staff, the public hearing was opened.
Mr. Ted Richmond, representing S.D.G.SE. gave a brief
report on the proposal and introduced Mr. Carthay M.
Lafune of 101 Ash, San Diego, who is Senior V.P. of
S.D.G.&E., Mr. Bob Lacey, Mechanical Supervisor, and
Mr. Dave Parkinson of Westec Services (firm that compilec
.. EIR), who each spoke to the Commission and audience in
great detail regarding the project and its long term
plans for SDGE, and the EIR impacts that .will result
from such a large undertaking by the firm. They spoke.
of the air emissions from the stack and the State
Standard for 24 hour emissions. They explained low sulpfjer
oil burning fuel contains much less than 0.5» suloher con-
tent and the steps that could be taken to eliminate
or lower the S02 removal from fuel. The S02 removal
systems are still in primitive stages, and the cost for
such a system for the 4 stacks would be approx. $35M
dollars. The cost for the single stack is approx. $5M.
They stated the 400 ft. stack at the bottom ne=sur=d 55 ft.
and at the top, 33 ft. They plan to decorate the new stack
to make it aesthetically attractive.
The Commissioners posed questions to the above gentlemen speakifig
for SDG&E and were advised there were no plans at the moment
for any additional units,, and stated if there were, they, would
have to come back before the Planning Commission. Mr. Lafune
advised that the present plans call for 5 units at the present
site.
Mr. Joseph Parrisi, local real estate man, 3344 Seacrest Dr.
Carlsbad, inquired where the project would be and asked to be
shown on the Map. Mr. Ted Richmond for SDG&E pointed out the
location. Uith no further questions or speakers, the public
hearing was closed.
The conditions were again discussed and Condition #8 & 10
were requested to be amended by Mr. Richmond. Mr. Richmond
provided the suggested amendment for Condition #10, and this
was made a part of the report.
There being no further discussion, A Motion was made that the
Planning Commission recommend to the City Council acceptance,
as presented, of the Final EIR for this project.
Motion was made that the Planning Commission recommend to the
City Council approval of Specific Plan #144, subject to the
amended conditions and additional wording as presented by
Ted Richmond and approved by the Planning Commission. It is
to be noted that this is an AMENDMENT to a previous specific
plan which had been approved.
-8-
MOTION:
Ayes:
MOTION:
Ayes:
I I
DRAFT
San Diego Gas § Electric Company
Encina Plant
Single Stack Modification Project
Environmental Impact Report
October 5, 1973
For
City of Carlsbad
1200 Elm Avenue
Carlsbad, CA. 92008
By
WESTEC Services, Inc.
1520 State Street
San Diego, CA. 92101
TABLE OF CONTENTS
FOREWORD
SECTION 1
SECTION 2
SECTION 3
SECTION 4
SECTION 5
SECTION 6
SECTION 7
SECTION 8
SECTION 9
SECTION 10
SECTION 11
SECTION 12
PROJECT DESCRIPTION
ENVIRONMENTAL SETTING
ENVIRONMENTAL IMPACT
ADVERSE ENVIRONMENTAL IMPACTS.
MEASURES TO MITIGATE ADVERSE EFFECTS
ALTERNATIVES
RELATIONSHIP BETWEEN SHORT-TERM USES
AND LONG-TERM PRODUCTIVITY OF THE
ENVIRONMENT
IRREVERSIBLE ENVIRONMENTAL CHANGE
GROWTH INDUCING IMPACT
BOUNDARIES OF AREAS AFFECTED
ORGANIZATIONS AND PERSONS CONSULTED
REFERENCES
Page
iii
1
9
15
33
35
37
43
45
47
49
51
53
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
CITY OF CARLSBAD ORDINANCE NO. 9279
AMBIENT AIR. QUALITY STUDY .
AESTHETICS PUBLIC OPINION SURVEY
FAA STACK STUDY
Figure
1-1
1-2
1-3
. 1-4
2-1
3-1
3-2
3-3
3-4
5-1
LIST OF FIGURES AND TABLES
Title Page
Vicinity Map SDG§E Encina Plant 2
Aerial photograph SDG§E Encina Plant • 3
Encina Plant Single Stack Modification Plan 6
Photograph of Encina Plant Proposed Single 7
Stack Modification
Existing Encina Plant Profile 10
Weather Balloon Simulating 400 Ft. Stack 19
Visual Impact Area - SDG§E Encina Plant 21
Expected Appearance of Encina Plant with 25
Four Units
Expected Appearance of Encina Plant with 26
400 Foot Single Stack
Photograph of Encina Plant Showing Effect of 36
Landscaping in 1985
Table
3-1 Population Estimates of Areas Visually Impacted 28
by Encina Power Plant
J
J
J
ii
J
FOREWORD
The Encina Power Plant of the San Diego Gas and Electric Company
(hereafter referred to as SDG§E) is located on a 680 acre parcel of
land in the City of Carlsbad (hereafter referred to as the City).
The plan for the development and utilization of the Encina power plant
is governed by City of Carlsbad Ordinance No. 9279.1 Presently SDGSE
is planning the addition of a fifth generating unit at the Encina
Plant. Environmental studies associated with Unit 5 have indicated
that a potential air quality problem exists in the vicinity of the
plant in terms of meeting State of California ambient air quality
standards for sulfur dioxide (S02). In order to preclude a possible
air quality problem, engineering studies were undertaken to determine
methods for ensuring compliance with the State air quality standards.
Based on engineering and economic factors the method of dealing with
the potential air quality problem is to provide a combined single ex-
haust emission stack at elevation 400 feet mean sea level (MSL) for
the plant. This stack will replace the existing four separate stacks
for Units 1-4 as well as accommodate Unit 5. Presently the applica-
tion of SDG§E for construction of Encina Unit 5 including the instal-
lation of a single stack is being considered by the California Public
Utilities Commission (CPUC). The City's land use plan for the site
as embodied in Ordinance No. 9279 allows for the construction of
Unit 5 without discretionary action on the part of the City. However,
the ordinance under Section 2, Item 5 requires that:
111
"The heights of future power generating buildings and J
transmission line tower structures shall be of heights
and a configuration similar to existing facilities..."1 -|
Thus, discretionary action is required by the City of Carlsbad to
allow construction of the 400 foot single stack and to accommodate . J
certain structural alterations on the roof of the plant. This en- -|
vironmental impact report covers those specific structural altera-
tions and additions associated with the 400 foot stack which require T
City approval via amendment to Ordinance No. 9279.
This environmental impact report has been prepared for the City J
of Carlsbad in accordance with their ENVIRONMENTAL PROTECTION PROCE-
DURES. In addition the contents of this report comply with the
State of California GUIDELINES FOR THE PREPARATION AND EVALUATION OF'
5
IV
-,
IMPACT REPORTS UNDER THE CALIFORNIA ENVIRONMENTAL QUALITY ACT OF 1970.
-«J'
lines on April 3, 1973. I
IThis report covers specifically the anticipated environmental im-
pacts (localized and regional, short-term and long-term) associated 1
J
with the 400 foot single stack and other roof top modifications. The
primary environmental issues associated with this project are health, J
compliance with air quality standards, aesthetics and safety. This .
S
report does not delve into the issues of the need for additional
system generating capacity in the form of Encina Unit 5 or any of the 1
environmental issues such as water quality control which are associated
solely with the new generating units and not related to the single J
stack or roof top modifications. These issues are the subject of ex- .
tensive studies by SDG§E and its consultants as well as the CPUC.
J
]
Public hearings into these matters have been held and the CPUC has
recently issued its draft environmental impact report covering the
Encina Unit application.
SECTION I
PROJECT DESCRIPTION
GENERAL PLANT DESCRIPTION
The Encina Power Plant is a totally enclosed, fossil-fueled,
thermal plant with the boilers, turbine-generators, and major aux-
iliary equipment contained within the plant building. The SDG§E
Encina Power Plant is located in the City of Carlsbad as shown in
the vicinity map, Figure 1-1. The property encompassed by SDG§E's
Encina operations is approximately 680 acres of land located east
of the Pacific Ocean and south of the north shore of the Aqua Hedionda
Lagoon, as shown in the accompanying aerial photograph, Figure 1-2.
The portion of the property on which the power plant is located
is zoned P-U (Public Utility Zone). The purpose of the P-U zone is:
"This zone is created to provide an area for the development
of certain public utility uses. The following uses only shall
be permitted in the public utility zone, unless as may be other-
wise provided for in this chapter:
41. Generation and Transmission of Electrical Energy..."
Thus the existing and planned uses of the site are in accordance with
the current zoning. The City's General Plan, although presently under-
going revision, reflects the current land use, and it is anticipated
that with regard to plant operations it will remain compatible.
A specific ordinance has been adopted by the City of Carlsbad
to cover SDG§E operations at the Encina Plant site (Appendix A). The
Company plans to add an additional 292 megawatts (MW) of generating
capacity at the Encina Plant in the form of Unit 5 as soon as approval
is attained (estimated start of construction, if approved, is 1974).
3—r'-—'•,
SDG&E
ENCiNA PLANT
^
SCALE 1:24000
SAN LUIS REY, CALIF.
NE/4 CCEANSIDE 15' QUADRANGLE
N3307.S — W11715/7.5
1%8
Figure 1-1. Vicinity map SDG&E Encinn Plant.
/
v A. V«<i, '.' ' /•• t^^'*'."
' J&/^" >•*->->^ ^^^- *•'*? JMv-^IL?/m* •>' iVM!*?' fc''>*Sf k^**W
?Ssi^l|l8i^"*^fe^'-^ftfi^" ^';^^iS|Z:vJfl;wi •^,*^8P.. j^ai**'.'"v ••••--.•!";" ''• •i'*Si;s-:^(1.-.-••*?*
HEDIONDA
LAGOON
:CITY OF CARLSBAD
Figure 1-2 Aerial photograph SDG&E Encina Plant
The existing three units and a fourth unit under construction have •*
a capacity of 632 MW (net). Thus, with the addition of Unit 5, "I
there will be a total net generating capacity of 924 MW requiring
a flue gas exhaust system at the Encina Plant. I
PROJECT DESCRIPTION 1
The Encina Plant single stack project consists of a single flue
1
gas exhaust stack which will replace the present 4 stacks and which J
will have the following general characteristics as compared to the ~|
r- • Jcurrent configuration:
1Existing Modified J
Characteristics Plant Plant
~8No. of Stacks 4 1 J
Stack Height - ft. 190 400
(mean sea level) «.J
Height of Stack 50 242
Above Roof - ft. ' 1
I
Stack Diameter - ft.
Top f(Unit 1-3) 12' (Inside 32'10" (Outside 1
Dia.) Dia.) J
Bottom (Unit 4) 14' (Inside 52'6" (Outside
Dia.) Dia.) I
HApproximate land area 2.5 5 -*
visibility range (mi.)
IIn addition to replacement of the existing four stacks with the single -"
stack, the project includes the necessary ductwork to route flue gases T
J
from each of the 5 units to the single stack. This results in a net
increase in the building roof top height of about 18 feet and the en- J
closure of the rooftop ductwork within a wall for aesthetic purposes.
The project also includes foundation work to accommodate the new stack -*
which extends approximately 91 feet to the east of the existing I
A ~m
building. Elevation and plan views of the proposed single stack mod-
ification are provided in Figure 1-3. A photograph of the existing
plant retouched to show the new stack is provided in Figure 1-4 so
that a visual perspective of the project may be gained.
A discretionary action is involved in this project since the
City of Carlsbad ordinance governing use of the.property requires
that the heights of future power generating buildings shall be of
heights and of a configuration similar to existing facilities (refer
to Appendix A, page 2, line 8.)
Plant Efficiency and Emission Products
San Diego Gas § Electric Company engineers estimate that the
400 foot single stack will have a negligible effect on plant efficiency
and hence generating capacity. This is due to the fact that an in-
crease in stack gas exhaust velocity (which promotes efficiency) ob-
tained with the new stack is offset by an increase in exhaust path
static pressure (which decreases efficiency) due to the added ducting
connecting the individual generating unit exhausts to the stack. Thus
any slight increases in generating efficiency are offset by the need
to increase forced draft.
The single stack project will have a negligible effect on
the production of air pollutant emissions by the Encina Plant. This
is due to the fact that combustion by-products (air pollutants) are
primarily a function of the type of fuel burned (such as natural gas
or fuel oil) and the combustion chamber conditions such as temperature
and fuel mixture. Consequently the single stack will have essentially
ROOF VENT (TVP.)
174
(TRANSFORMS* AREA)
ROOF VENT (TYP.)
*'*•-«-
STAIRS PENTHOUSE
H CD Q
PLAN VIEW
SCALE 1" 62.5 -0 '
LIOHTNINO RODS TOP OF LINER
ELEV. 400-0
r— TOP OF • REECHINO ^
\ EI_ ur-r <TTP.) ^^2r
1
I
I 1
-<v-OF 5 UNI
*-^ <
i
1 i
i
I
fL iui L
rs UP T
ROOF
140-3V
GRADE
ELEVATION VIEW (LOOKING WEST)
SCALE 1" = lOO'-O"
** n -10 o.o.
-> n J> I.O. LINER
12-0 I J4 J)
TOP OF FDN.
CLEV. 1« -0
BOT./SLAB ELEV. r-»' C ^ _"Vl^^"J
ELEVATION VIEW (LOOKING SOUTH)
SCALE 1" = 100'-0"
Figure 1-3. Encina Plant Single Stack Modification Plan.
1 4 tL - - -3WHUttHi mAMtf
»"tj>.1SS^, ft
1&
Figure 1-4. Enema Plant retouched photograph showing the proposed single stack modification (as viewed approximately3800 ft. southeast of the plant across 1-5).
no effect on the production air pollutants, but rather it will impact
the manner in'which these pollutants are dispersed into the atmosphere. j
NEED FOR THE PROJECT T
The purpose of the single stack project is to ensure compliance
1with State ambient air quality standards. During the environmental J
impact studies for Eitcina Unit 5 it was determined that a potential -»
Iair quality problem exists near the plant in terms of sulfur dioxide
(S02) concentrations at ground level. In order to meet State S02 "1
standards it was necessary to devise a means for reducing ground
- 1level SO concentrations downwind of the plant. The single stack f
modification was selected as the most acceptable means of accomplishing -j
this. The air quality aspects of the project are discussed in Section 3
under Air Quality Impacts. |
J
J
J
SECTION 2
ENVIRONMENTAL SETTING
CURRENT PLANT CONFIGURATION
Since the project being addressed by this EIR is the single stack
and the roof top ductwork modifications to accommodate the stack, this
is the environmental setting which is addressed'.
The present plant has 4 separate stacks (serving Units 1-4) at
elevation 190 feet (MSL) as described in Section 1. The original
intent was to provide a fifth stack at the plant of similar configur-
ation and height to the existing stacks. However, air quality studies
(as discussed in Section 3) have indicated that such a configuration
could result in unacceptable ground level concentrations of sulfur
dioxide. The current configuration of the Encina plant as viewed
east of 1-5 is shown in Figure 2-1.
AIR QUALITY FACTORS
Standard Research Institute as an element of continuing environ-
mental research associated with the Encina plant conducted a meteor-
ological and air quality sampling program for the area around the
plant.6 Quoting from the summary and conclusions of this work:
"Inspections of vegetation in the region within a radius
of 15 miles of the Encina plant were made during the spring,
summer, and fall of 1971 and the winter of 1972. These in-
spections indicated no plant damage ascribable to either
N02 or S02 emissions from the Encina plant. Although no
S02 damage was found anywhere in the area, slight to moderate
photochemical smog damage was found near freeways. The
damage noted was caused by ozone and peroxyacetyl nitrate
and probably by N02, components found in photochemical smog.
The severity of the photochemical smog damage noted did not
correlate with the distance of an affected area from the
Encina plant. This indicates that the pollution levels
* '- *"*H '
' ' '» -.. ...„•,
., « •* '" -<«*»» *»,--,r - -M- - - r* .. , 'v
Figure 2-1 Existing Encina Plant profile (view from point 3800 ft. southeast of plant looking across 1-5.
"produced by the Encina plant emissions are not now high enough
to cause plant damage.
Nitrogen oxide concentrations in the Carlsbad area
showed a fairly consistent pattern during the year. The
maximum increase in measured NO concentration due to
Encina plant emissions was O.Olb ppm. This concentration
is much less than the predicted values of 0.090 ppm NO
for the maximum ground level concentration 1 mile downwind,
based on an 85-gm N02/s emission rate into an atmosphere
with a neutral stability and a 10-mph wind.
On the basis of the above maximum NOX upwind-to-down-
wind concentration ratio, and assuming that new stack par-
ameters are the same as the existing stack parameters,
doubling the size of the Encina plant will increase the
maximum average NOX concentrations to, perhaps, 0.035 ppm
at the ground. This should produce a maximum NOX concen-
tration, including background of about 0.040 ppm in the
area 1 mile downwind of the Encina plant.
The NOo, NO, and NO concentrations found near the
Encina plant are compared with the concentrations found
in nearby communities in tables in Section IV. These
comparisons indicate clearly that pollution sources other
than the Encina plant control the ambient concentrations
in the surrounding western central Sari Diego County regions.
The measurements of NO, N02, and NOX concentrations
in nearby communities corroborate our vegetation damage
findings that nitrogen oxides are emitted principally from
a different source. This source appears to be a diffuse
area source and is assumed to be largely automobile emissions.
Sulfur dioxide concentrations showed a very large var-
iability during the periods when fuel oil was burned at
the Encina plant. The maximum ground level concentration
1 mile downwind was calculated on the basis of 0.5 percent
sulfur fuel being burned in two of the three units. The
predicted concentration is 0.130 ppm S02- On three occasions,
S02 concentrations downwind of the Encina plant were measured
at about 0.090 ppm, with stable meteorological conditions and
10-to-12 winds. Background SOo measurements showed about
0.009 ppm fairly consistently during the year.
Following the intermittent sampling period S02 was
continuously monitored at the ground point of maximum con-
centration for 5 consecutive 24 hour periods while burning
0.5 percent fuel oil in all three units. The 24 hour average
concentrations ranged from 0.027 ppm SO, to 0.030 ppm S02and the five day average was 0.028 ppm 502-"
11
These measured 24 hour average concentrations are con- I
siderably less than the 0.04 ppm California air quality stan-
dard. However, a three fold, even a 'two fold increase in _
the Encina power plant capacity makes it necessary to con- I
sider changes in design and operating procedure in order to •-*
meet the 24 hour California S02 standard."
Thus the key finding of the study was that existing air quality
in the plant vicinity for those factors associated with its operation "1
(NOX and SCO is satisfactory, but that the addition of new generating
units could cause the California 24 hour S02 standard to be exceeded. I
AESTHETICS 1• . fl
The existing plant configuration and profile as shown in Figure _
I2-1 is a familar landmark to residents of the Carlsbad area as well *
as passing motorists on Highways 1-5 and State 21. The visual impact 1
area of the existing plant is shown in Figure 3-2 under the discussion
of aesthetic impacts. Moreover a comprehensive comparison of the J
aesthetic characteristics of the existing plant as compared to the
modified plant is provided from the standpoint of citizen reaction. *
' 1PUBLIC SAFETY J
Air Traffic J
The existing plant stack height is 190 feet above sea level. By
!FAA regulations the plant does not constitute a possible air traffic J
"obstruction" and is therefore not a hazard to air navigation. The T|
existing 4-stack plant is not lighted or marked.
JOcean Navigation Aid
The existing plant is frequently used as an aid to navigation I
by ocean going vessels operating in the off-shore areas contiguous
J
12
J
to northern San Diego County. Assuming that a shipboard viewer is
at a point 15 feet above the waterline, the stack can be viewed on a
clear day out to 21 statute miles.
SOILS AND GEOLOGY
The area immediately east of the power plant building (to approxi
mately 90 feet) where the new stack foundation will be located is pre-
sently unused land. The general geologic and soils conditions at this
spot are typical of conditions found at the power plant site as de-
scribed in the Environmental Impact Report for Encina Unit 5. These
conditions are summarized below. • .
Directly underlying the development site are marine terrace de-
posits of Quaternary age. This unit probably corresponds with the
Lindavista Formation encountered further south in San Diego County.
The unit consists of soft to moderately hard c.laystone, sandstone
and conglomerate. Although it underlies the entire power plant site,
this formation is generally not laterally extensive, and is relatively
thin.
The Torrey and Del Mar Sandstones, of Eocene age, underlie the
terrace deposits. These sands are poorly to moderately cemented and
easily eroded. The sedimentary rocks (the sandstones and terrace
deposits) are all nearly flat lying in the vicinity of the power plant
site.
General soil conditions at the plant site consist mainly of very
dense sandy soils. These soils are lightly to moderately cemented,
and contain varying amounts of silt and clay, with occasional concen-
trations of gravel.
13
SECTION 3
ENVIRONMENTAL IMPACT
GENERAL
The Encina plant single stack project will cause environmental
impacts in the following areas:
e Air Quality
e Aesthetics
9 Public Safety
Each of these impacts (both short-term and long-term) is discussed in
this section. It is important to understand that this report does
not address the broader aspects of SDG^E's need for additional system
generating capacity or the application for Encina Unit 5. These ele-
ments arc not being judged separately by the City cf Carlcbad, but
Q
rather are being considered under an application to the CPUC. The
only environmental impacts addressed in this report are those factors
which by discretionary action the City of Carlsbad must amend for the
Encina plant land use plan.
Air Quality
Existing air quality conditions near the Encina plant were dis-
cussed in Section 2. For a comprehensive analysis of the existing
air quality conditions in the vicinity of the plant the reader is
referred to the Environmental Impact Report for Encina Power Plant
Unit 5.7 This report is available for review at the City of Carlsbad
Planning Department or from San Diego Gas and Electric Company.
15
Based on the air quality survey work, it was determined that,
with the existing stack height, the emissions from Units 1 through 5
would cause ground-level sulfur dioxide concentrations in excess of
the ambient air quality standards.^ Consequently a study of methods
to improve air quality was undertaken by SDG^E's consultant, the ^,
1Bechtel Power Corporation. The results of this study are provided as .-1
Appendix B to this report. Quoting from this report: "1
"Flue gas emitted from a power plant stack rises due to its
upward momentum and buoyancy, is transported horizontally -a
by winds, is dispersed by the turbulent eddies present in J
the atmosphere, and is gradually diluted by mixing with the
ambient air. As a result of the elevated release, plume ,
rise, and downward dispersion, the ground-level pollutant 1
concentration at a typical power plant varies from nearly ~"
zero directly under the stack, to a maximum 1 to 5 miles
downwind, and back down to nearly zero several miles from I
the plant. In the Encina Unit 5 Environmental Report,(1) J
the commitment was made to design the Encina Power Plant so
that the ground-level concentrations are within the ambient ~|
air quality standards promulgated by all levels of govern- J
ment. The effect of the Encina Power Plant on air quality
was studied to determine the plant stack modifications ,
necessary to maintain acceptable air quality with the plant 1
expansion to 924 MW. -*
Three factors, specific to the Encina Power Plant and its i
location, required special attention in order to determine J
a stack configuration and height that would disperse flue
gas adequately and maintain ground-level ambient air quality a
within the standards. These factors were: J
o Aerodynamic downwash .
Ie Inversion-limited mixing * --*
• Sea breeze effects 1
J
The power plant building with its long axis perpendicular
to the prevailing sea breeze is a large obstacle to air flow a
and therefore displaces streamlines and causes a large tur- J
bulent region downwind of the building. If the plant stacks
are not sufficiently high, flue gas emissions will be caught .
in the aerodynamic downwash behind the building and will be 1
mixed rapidly to the ground, causing excessively high ground- J
level concentrations."
16
J
1
There are alternative methods available to maintain groundlevel
concentrations of emissions from the Encina plant within the ambient
air quality standards. These are discussed in Section 6 of this re-
port. The technique which SDG§E has selected to meet air quality stan-
dards is to discharge flue gas from all five boilers (924 MW) to the
atmosphere through a single stack, 400 feet above mean sea level. By
discharging through a single stack rather than five separate stacks,
higher plume rise and lower ground-level concentrations can be achieved
(refer to discussion Appendix B., p. 5A. 2-1).
Air quality studies for 325 and 400 foot single stacks showed
that the California 24 hour average sulfur dioxide standard could be
exceeded with a 325 foot stack, but that a 400 foot stack provided
sufficient insurance that the SO standard would be exceeded only on
• - •• • -£
rare occasions (less than 1 day per year on the average). This situ-
ation would only occur under certain meteorological conditions when
burning fuel oil of the maximum permissible sulfur content (.5% by
weight). Considering the current nation-wide energy problem it seems
prudent to expect an increasing dependence on fuels of this type.
However it should be pointed, out that fuel oil with .51 sulfur is con-
sidered to be low in sulfur content. Currently SDG§E, when unable to
obtain natural gas, burns fuel oil ranging from about .3-.41 sulfur
content. No other air quality standards would be jeopardized by the
plant when expanded to 924 MW capacity.
Summary of Air Quality Impacts
Summarized, the air quality impact of the 400 foot single
stack is a beneficial and required one. The stack does not effect the
production of air pollutants by the Encina plant, but rather the manner
17
in which pollutants produced by the plant are dispersed to the atmo-
Isphere. The 400 foot stack ensures the maintenance of all ambient -•*
air quality standards under the anticipated range of operating condi- "1
Jtions when the plant is expanded to 924 MW. In particular the stack
1will preclude ground level sulfur dioxide concentrations from exceeding J
State standards. Moreover it significantly reduces aerodynamic down- _
wash of emissions from the plant which is an existing adverse factor. -*
The 400 foot stack in addition to ensuring the maintenance of ambient "1
J
air quality standards should also deter any downwind odor problems
1(particularly sulfur dioxide) which the current stack design can induce J
because of the aerodynamic downwash pheonomena.
1Aesthetics
Aesthetics is the science and art of protecting and helping to If
create that which is beautiful, attractive and pleasant. It is sub-
J^
.
Thus, that which has aesthetic appeal to one person may be unattractive a
to another. The purpose in this case is to obtain a measure of the
J'
.
Visual Impact Area
One measure of aesthetic impact is to determine the area of J
visual impact of the modified plant in relation to the existing plant. »
J
The visual impact area of the present four-stack (190 foot MSL) plant '
was determined by direct sightings of the plant which were made through- 1
out the immediate surrounding land area. To determine the visual im-
pact area for the 400 foot single stack, a weather balloon was used J
to. represent the proposed height (Figure 3-1). The balloon was an- .
chored atop the northern most stack which was out of service at the
time (August 24, 1973) and was sent up during the morning hours when 1
18
Figure 3-1. Weather balloon simulating height of 400 ft. stack to determine visual impact area.
19
winds were calm. The visual impact area was then determined by *
sightings throughout the Carlsbad and Oceanside areas. The visual "1
impact area of the existing and modified plant are shown on the land
area map in Figure 3-2. For reference, distance radii from the plant J
are plotted on the map. It should be noted that there are blind areas
or pockets within the impact boundaries from which one cannot see the -*
plant due to landscaping, bu:Iding obstruction or other factors, but "1
J
that these were not determined due to accessibility and time factors.
The impact area boundaries are thus generalized and represent for the J
most part the maximum impact distances.
IThe visual impact land area of the Encina plant in its pre- *
sent form encompasses approximately 9 square miles and ranges from 1
approximately Carlsbad Boulevard on the north to Batiquitos Lagoon
on the south. It can be seen from as far inland as the Palomar Air- J
port and the slopes of Mount Marron (.La Costa) . Topography is the ..„
limiting factor in viewing the existing 4-stack plant. *
The visual impact area of the proposed 400 foot stack will |
.1
encompass a much larger area (approximately 34 square miles) and will
extend from Oceanside pier on the north to Leucadia on the south. In- J
land the single stack will be seen from the Mission Mountain and Fire
I
Mountain areas of Oceanside, the predominantly agricultural areas be- J
low Cerro de la Calavera, and the developing residential areas below 1
Mount Marron (La Costa). Topography also limits the 400 foot stack
Bvisual impact area. . J
A major limiting factor for visual impact of the single 8
stack will be meteorological conditions. Low clouds, fog, haze and -*
J
20 J
mm?Mmf$smv{Sll§9^W
Figure 3-Z Visual impact area — SDG&E Encina Plant.
21
smog all periodically reduce visibility in the area. According to
National Weather Service records for Palomar Airport during the day-
light hours (nominally 0600-1800) the condition of a ceiling less than
1500 feet and/or visibility of less than three miles occurs about 27.4%
of the time. The condition of a ceiling of less than 300 feet and/or
visibility of less than 1 mile occurs 3.-6% of the time. The predomin-
ance of the visual impact area is under three miles from the Encina
plant and as such the single stack will be difficult to distinguish
about 25% of the time depending on the viewers' distance from the plant
Moreover, the sea tone coloring of the single stack and the plant will
also reduce its visibility factor.
Aesthetic Value
Because aesthetic values are a very personal judgment it
was appropriate to seek the opinions of those living in the visual
impact area with regard to the appearance of the 400 foot single stack
and associated building modifications. Consequently a public opinion
survey was performed during the period August 17-20, 1973 by Central
Surveys, Inc. The primary purpose of the survey was to measure public
reaction to the proposed visual changes to the Encina plant as
addressed by this report.
The preparer of this EIR, WESTEC Services, Inc., did not
conduct the survey. However WESTEC Services did provide input to the
survey firm, Central Surveys, as to the nature of questions to be
asked and WESTEC Services did concur with the questionnaire and sur-
vey approach prior to its use. WESTEC Services is satisfied that the
questionnaire and survey approaches used by Central Surveys were
23
valid and without prejudice either for or against the proposed plant
modifications. WESTEC Services considers the results to reflect a
reasonable and valid cross section of public opinion with regard to
the aesthetic impact of the planned plant modifications. • The com-
plete results of the survey are provided herein as Appendix C.
The impact area for the survey encompasses residences both
within the current visual impact area and in the extended impact area.
It will be noted that the impact area map of the survey firm as shown
in Appendix C is somewhat different from the impact map shown in
Figure 3-2. This is because the impact area visual sightings had not
been performed prior to the development of the survey format. The
differences however are not relevant to the findings since all persons
questioned during the survey resided in the current or extended im-
pact area as ultimately determined by sightings. During the survey
those questioned were shown two photographs of the plant. The first
photograph presented here as Figure 3-3 shows the existing plant as
viewed from the hill above the north shore of Agua Hedionda Lagoon
about 4,800 feet northeast of the plant. A second photograph pre-
sented here as Figure 3-4 shows the plant as it will appear after the
single stack modification from the same location. It is a retouched
photograph. The respondents were asked the following question:
"This picture (Figure 3-3) shows the expected appearance
of the plant with the present four units. This picture
(Figure 3-4) shows the addition of a fifth unit, the
single taller stack, and an 18 foot height extension to
the building exterior to hide ductwork and additional trans-
mission facilities. Which do you think has the better
•appearance?"
24
J
J
Figure 3-3 Expected Appearance of Encina Plant with Four Units
1973
Cn
',~ZZ * &&f&-~.&fif/f~r*-r' -I/- v~
Figure 3-4 Expected Appearance of Encina Plant with 400 Foot Single Stack
197?]
O\
r.' a ~——•• '^Ja.-:- ""• •.•-^-»^t-
The results were:
Present appearance is better - 19%
Proposed appearance is better - 72%
No opinion, no difference - 9%
There were degrees of preference and reasons for their feelings given
which are explained in Appendix C. Later in the survey those who felt
the proposed appearance was worse or expressed no opinion were ex-
plained the reason for the new stack (to reduce the ground-level con-
centration of pollutants downwind from the plant) and were asked if
this altered their position. On this basis 83% of those questioned
favored the new stack and 6% opposed it. This latter factor however,
reflects both aesthetic and air quality opinions.
In summary then, from an aesthetic standpoint, a substantial
majority of residents (72%) in the impacted area consider the single
stack and associated building modifications to be beneficial whereas
a minority (19%) consider it adverse.
Population Factors
Residents Affected
The number of area residents whose view is or will be
affected by the existing plant or the modified plant is shown in
Table 3-1. The census tracts considered are those wholly or partially
within the visual impact areas shown in Figure 3-2. Judgments were
made as to the percent of each census tract that is a part of the
impacted area, the percent of the population within the impacted
area of each census tract that is exposed to the plant, and the
27
TOTALS
TABLE 3-1
Population Estimates of Areas
Visually Impacted by Encina Power Plant
Persons Affected By Persons Affected By
Census
Tract No.
176.00
177.00
178.01
178.02
179.00
180.00
181.00
182.00
185.01
185.03
185.04
198.00
200.03
Tract Pop.
1970
3365
4119
3719
4097
4528
2177
4443
4869
6201
4876
3007
1385
377
Existing
1970
17
288
744
3892
2717
1415
22 -
7
Stacks
1975
20
315
698
6071
2865
1822
23
7
117
Proposed
1975
409
674
3496
6071
4775
2803
2312
2278
623
36
2108
68
2345
400' Stack
1985
658
761
4621
20178
5325
3326
5322 .
2407
675
2165
2165
380
10831
47163 9102 11938 27998 56691
Notes:
1. Total tract population 1970 is based on 1970 U.S. Census.
2. Total tract population 1975 = 58,909 based on Comprehensive
Planning Organization estimates
3. Total tract population 1985 = 102,244 based on Comprehensive
Planning Organization estimates
J
J
J
J
J
28
probable distribution of growth within each census tract. These
judgments were based on field observation, topography, and growth
data of each census tract. Table 3-1 shows that in 1975, when the
single stack is scheduled for completion, approximately 12,000 persons
will reside in the visual impact area of the existing stacks, whereas
about 28,000 persons will reside in the impact area of the 400 foot
stack. Thus approximately 2 1/3 more area residents will be visually
affected. By 1985 it is anticipated that approximately 56,700 resi-
dents will reside in the visual impact area of the 400 foot stack.
Motorists Affected
A large number of people are exposed to the Encina plant
as they drive along the main arteries through the Carlsbad area.
Current traffic volume on Interstate 5 is estimated at 49,500 cars/
day." By 1975 traffic on 1-5 is projected to increase to about 61,000
cars/day. As a measure of plant visibility by passing motorists the
total viewing time for the existing and modified plant can be compared.
•Presently the plant is visible about 1.3 miles north on 1-5 and 2.4
miles south. With the 400 foot stack this will increase to 4.2 miles
north on 1-5 and 4.2 miles south. Considering the 1975 traffic and
assuming a 60 mph average speed the viewability factor to passing
motorists can be estimated as:
Viewed from Viewed from Total Traffic Total View-
North of Plant South of Plant (One Way) ability Factor
Existing Plant
Modified Plant
1.3 minutes
4.2 minutes
2.4 minutes
4.2 minutes
30,500
30,500
1880 hrs.
4270 hrs.
29
Thus the modified plant (assuming adequate visibility conditions) will
be about 2.3 times more viewable by passing motorists traveling on 1-5.
Public Safety
Air Traffic
The Federal Aviation Agency (FAA) has conducted a study of
the proposed 400 foot single stack. The report of this study is pro-
1vided herein as Appendix D. The FAA study concludes that the single |
stack "would not be a hazard to air navigation". Because of its -»
height (greater than 200 feet) and the fact that light planes often
travel along the coast at low altitude to stay below the cloud cover, 1.1
the stack must be marked and lighted according to FAA standards. This
would normally require that alternating red-orange bands or squares f
be applied to the stack and a lighting system which can be seen from -j
Iany direction be installed at one quarter intervals up the stack.
The lighting would be used from one-half hour before sunrise to one- 1
half hour after sunset. For aesthetic reasons an alternative recog-
nition plan is being planned which would have the stack marked with f
flashing white strobe lights for daytime warnings. The nighttime n
lights would be fixed and rotating red lights as is normally required.
The decision on the warning features of the stack will be made in |
Jt
consort with the City of Carlsbad (See Appendix D).
1Palomar Airport is about 3 miles from the stack. While not J
constituting a hazard to air navigation as defined by FAA standards .
it is anticipated that the new stack will provide benefit as an air
navigation aid. . I
30
J
Ocean Navigation
One impact of the 400 foot single stack will be to provide
an improved navigation aid for ocean-going vessels off the Southern
California coast. The factors limiting visibility of the stacks at
sea are weather and the curvature of the earth. On a clear day,
assuming that the observer aboard a ship is 15 feet off the water,
the maximum distance that th? stack can be viewed is figured as
follows:
in nautical miles = 1.15 x "V Height of stack (in feet)
d£ in nautical miles = 1.15 x V Height of eye (in feet)
Thus, if H-^ is 190 feet (existing stacks) and H2 is 15 feet
(observer height), then d, + d2 = 15.85 + 4.45 = 20.3 n. miles
(23.3 miles). Using the same formulae, the proposed single stack at
400 feet could be seen from approximately 31.5 miles out to sea. Due
to weather factors (haze, fog, etc.) this maximum value is very in-
frequently realized. Probably more important than the increased
distance factor is the increased viewability of the stack in the off-
shore areas out to perhaps 10 miles. .Certainly the prominence of the
structure due to increased diameter and height will increase its bene
fit as a navigational aid particularly to pleasure craft and fishing
vessels.
31
Geologic Hazards J
A number of geologic factors are being considered in _
Iengineering the structural design of the 400 foot stack. These factors, J
each discussed below, are: potential seismic shaking, possible lique- ~1
faction of underlying soils, and the compressability of underlying
soils. J
With regards to seismic risk, the stack will be designed to -_
Iwithstand the potential earthquake intensities and seismic accelera- J
tions as summarized on page 2.4-4 of the EIR prepared for Encina ~|
Unit 5. The absence of loose sand strata and the abundance of very
1dense, cemented sands beneath the development site indicate that, in g
case of seismic shaking, soil liquefaction is unlikely. _,
1The load-bearing capacity of the high-density, fine to J
medium sand and sandstones is adequate to support the proposed stack "|
.,a
without adverse compression and settling problems.
Thus the geologic factors associated with the stack founda- J
tion area are such that standard conservative engineering techniques _
Ishould preclude any dangers due to structural failure of the stack. J
J
J
32
J
SECTION 4
ADVERSE ENVIRONMENTAL IMPACTS
AESTHETICS
Although a large majority of the residents of the visually im-
pacted area (about 72%) would appear to prefer the single stack over
the existing configuration, there will be nevertheless a percentage
of area residents (about 191) who consider that the project will
cause an adverse aesthetic impact. Based on the preferences of these
persons then, some adverse aesthetic effects will accompany the pro-
ject from their viewpoint. Additionally the project will significantly
increase the area from which the plant stack can be seen. Currently
an estimated 9 sq. miles of land area are visually impacted by the
plant. With the single stack project this will increase to about
34 sq. miles of land area. Thus areas with no visual impact currently
will experience a visual impact with the new stack.
Measures to mitigate these factors are discussed in Section 5.
33
SECTION 5
MEASURES TO MITIGATE ADVERSE EFFECTS
AESTHETICS
The following measures to mitigate adverse aesthetic effects that
some persons will consider to accompany the single stack project are
planned by SDG$E:
1. An 18 foot facade will be constructed on the top of the
building to conceal ductwork and essentially smooth
building lines which are now somewhat irregular
(See Figure 1-3).
2. The stack will be painted a sea-tone gray to blend it
with the background seascape. Checkered patterns for
aircraft warning will be obviated by the installation of
strobe warning lights to satisfy daytime visability re-
quirements.
3. Property areas adjacent to 1-5 and S-21 are being land-
scaped to provide visual relief from the plant facilities.
Figure 5-1 shows an artist's conception of landscaping
along 1-5 and the effect it will have on shielding the
plant from the view of passing motorists and those
living on the north shore of Agua Hedionda Lagoon. Note
that the photograph represents the plant in 1985.
35
198'
j.-'c »*#&* ~£*^f®J\ * *f
'/"-•4
.'-*». «^*-'^«w*>*«/-».r»,^ „ * vi» __J^ -. oi _ *#* *, * r/
' ^° "^'y**"i^^^^'^^*^^^^';^^4^^^ % '^'Cj--'' f* ' ^ \l* "< ' ^ ^ *> " ' ' -, " <. ' v. v .V, ' V"?™:*^z"*at*8a^^
Figure 5-1. Encina Plant retouched photogra])h showing effect of landscaping in
1985 (view from 4800 ft. northeast of the plant across Agua Hedionda Lagoon).
—i U-J
SECTION 6
ALTERNATIVES
ALTERNATIVE APPROACHES
Alternatives to the single stack 400 feet above mean sea level
project are:
1. Fifth stack for Unit No. 5.
2. Use of natural gas (to reduce S02 emissions).
3. Very low sulfur content fuel oil (.3% sulfur or less).
4. S02 scrubbing system.
5. Plume dispersion techniques
a. Increase height of existing stacks
b. 325 foot ..single stack
Each of these alternatives is discussed in this Section along with
the reasons why SDG§E rejected the approach.
Fifth Stack for Unit 5
Before San Diego Gas £ Electric Company made its decision to
build a single stack 400 feet above mean sea level for the Encina
plant, alternatives to that stack were considered. The problem at
Encina as discussed in Section 3 which required that such a stack be
built or that an alternative solution be developed, is that of main-
taining ground level ambient air quality in the vicinity of the plant,
Units 1 through 4 at Encina each employ a separate 190 foot stack for
the discharge of flue gases and other combustion emissions. The Com-
pany had originally planned to use a fifth such stack for Unit No. 5.
37
However, before it made a commitment to a given stack design, the ~|
Company commissioned a study of the expected ground level concentra-
tions of flue gases when all five units are in operation. The study J
was a mathematical analysis employing plume dispersion models ~i
(Appendix B). The results of the study indicated that the ground
level concentrations of sulfur dioxide (802) emitted from the Encina J
plant with Units 1 through 5 in service would exceed the maximum
24-hour average concentrations set forth in the State Air Resources J
Board's ambient air quality standards. Based on this data an addi- -i
tional 190 foot stack was unsatisfactory and an alternative means of
controlling SC^ concentrations had to be .implemented. I
There are two possible fundamental approaches to resolution of
such a problem. Either SO^ emissions must be reduced or the emissions J
must be dispersed in buch a way as to avoid excessive concentrations. -g
Both of these approaches were examined.
Natural Gas Combusion
38
1
The amount of S02 that leaves a power plant boiler is directly 1
proportional to the sulfur content of the fuel burned in the boiler.
One possible solution, therefore, is to burn fuel with a lower sulfur J
content. Since natural gas is virtually sulfur-free, there is no S02 ,
problem when that fuel is being burned. However, natural gas is not . J
always available, and its availability for power plant use is expected ~|
to be virtually eliminated within the next few years, because of the
increasing demands for natural gas by higher priority uses such as J
residential consumption. This is a national problem.
J
]
]
Very Low Sulfur Content Fuel Oil
The alternative to natural gas, for use at the Encina plant, is
fuel oil which contains very low amounts of sulfur, depending upon the
particular type of oil. San Diego Gas § Electric Company uses, and
plans to use, low-sulfur fuel oil, with a sulfur content of not more
than 0.5% in all of its conventional steam generating units. An
assured supply of fuel oil with a still lower sulfur content is not
available in the quantities required by Encina plant operation according
to a Company spokesman. Moreover, the plume dispersion studies in-
dicated that the problem of excessive SC>2 concentrations would require
extensive stack modifications, even if 0.31 sulfur content fuel were
burned at Encina. The use of lower sulfur content fuel oil is there-
fore not a viable solution according to SDG§E.
SOo Scrubber Systems
Another method of limiting emissions from the plant would be to
install an S02 scrubbing system for removal of S02 before the flue
gases are discharged. This alternative was also examined by San Diego
Gas 5 Electric Company, but it was rejected for several reasons.
S07 removal systems are apparently still in the experimental and pro-£*
totype stages. It would take a third or fourth generation design to
obtain complete reliability for such a system. The cost of such a
system for a plant the size of Encina, based on a conservative $40
per kilowatt, would be $36 million according to SDG$E. The cost of
the proposed 400 foot stack will be $5 million. Finally, an S02 re-
moval system would be quite large, and it would be difficult to locate
it on the power plant site. The aesthetics of such an installation
39
would also present a problem. The Company considered it unwise to J
install such a costly system which would be aesthetically unappealing, -i
difficult to site and of dubious effectiveness.
Plume Dispersion J
The Company evaluated plume dispersion techniques for which there "1
were three basic alternatives. The height of all five stacks could
be increased by 100 feet, which would be the maximum increase possible J
for roof mounted stacks. The height of the Unit 1, 2 and 3 stacks __
could be increased by 100 feet and the flue gases from Units 4 and 5 •*
could be combined to increase plume buoyancy and.discharged through ~!
a single 290 foot stack. A single stack could be employed for all
five units. .:..,. f
The first plume dispersion alternative mentioned above, five
290 foot stacks, was examined. It was found that even if the stacks -"
were nozzled to increase discharge velocity and the flue gas exit 1
I
temperature were elevated to increase buoyancy, the influence of the
stacks, would still cause unacceptable ground level S02 concentrations.
The second alternative, four 290 foot stacks, was examined and re- •
jected for the same reasons (Refer to Appendix B) . 1
That left the alternative of a single stack and the remaining
issue was how high the stack had to be. In order to remove the plume J
from the influence of the downwash, a rule of thumb has it that the ^
stack must be between 2 and 2.5 times the height of the building. J
This rule of thumb has been verified by wind tunnel studies and ex- J
perience at operating plants. This rule of thumb was further verified
J
40
for application to Encina by computer modeling. This meant that when
the ductwork necessary to permit all five units to use a single stack
is added to the top of the power plant building, a stack of 325 to
400 feet in height will be required to escape the downwash effect.
The decision to build a 400 foot stack rather than a 325 foot
stack was dictated by the critical inversion height for stacks of
those heights. The critical inversion height is the lowest height at
which a plume from a given source will not pierce the inversion and be
dispersed over a wide area in the calm air inversion layer. If in-
version is below the critical height the ground level concentrations
are alleviated. If it is above the critical height more vertical
mixing will occur and thus reduce ground level concentrations. If
inversion is at the critical height, the plume will not pierce the
inversion and it will have the minimum dilution caused by vertical
mixing.
Because of the difference in the critical inversion height for
these two stack heights, and also because of the tendency of the sea
breeze to bend a plume downward even if inversion exceeds the critical
inversion height, use of a 325 foot stack would still have permitted
ground level concentrations of SC>2 from Encina to exceed the State
24-hour average standard to be exceeded. The Company therefore choose
the 400 foot stack design to comply with that standard.
41
SECTION 7
RELATIONSHIP BETWEEN SHORT-TERM USES AND
LONG-TERM PRODUCTIVITY OF THE ENVIRONMENT
The purpose of the proposed 400 foot stack is to ensure
compliance with the California 24 hour S02 ambient air quality
standard. This standard is based on protecting, public health.
Thus the project is one aimed at ensuring long-term productivity
of the environment by meeting health-related standards.
43
SECTION 8
IRREVERSIBLE ENVIRONMENTAL CHANGE
There are no irreversible environmental changes associated with
the proposed 400 foot stack.
45
SECTION 9
GROWTH INDUCING IMPACT
There are no aspects of the stack modification project which are
growth inducing.
47
SECTION 10
BOUNDARIES OF AREAS AFFECTED
(Refer to Section 3, Figure 3-2 for visual impact area boundaries)
49
SECTION 11
ORGANIZATIONS AND PERSONS CONSULTED
GOVERNMENTAL AGENCIES
City of Carlsbad, Planning Dept.
City of San Diego, Environmental Quality Dept.
County of San Diego, Environmental Development Agency
Comprehensive Planning Organization
Federal Aviation Administration, Dept. of Transportation
National Weather Service, Lindbergh Field
State of California, Div. of Highways, Dept. of Transportation
PRIVATE ORGANIZATIONS
Bechtel Power Corporation
Central Surveys, Inc., Shenandoah, Iowa
San Diego Gas and Electric Company
INDIVIDUALS
Two hundred residents of the Carlsbad area were surveyed by
Central Surveys, Inc. (See Appendix C).
51
SECTION 12
REFERENCES
1. City of Carlsbad, An Ordinance of the City of Carlsbad, Adopting
a Specific Plan on Approximately 680 Acres of Land Located East
of the Pacific Ocean and South of the North Shore of the Aqua
Hedionda Lagoon, Subject to a Portion of Said Property Being
Annexed to the City of Carlsbad (Ordinance No. 92^9);
August 3, 1971.
2. City of Carlsbad, ENVIRONMENTAL PROTECTION PROCEDURES (Ordinance
No. 1158); April 3, 1973.
3. State of California, Resources Agency, GUIDELINES FOR THE PREPAR-
ATION AND EVALUATION OF ENVIRONMENTAL IMPACT REPORTS UNDER TflE
CALIFORNIA ENVIRONMENTAL QUALITY ACT OF 1970; February 5, 1975.
4. City of Carlsbad, (Title 21, Chapter 21.36).
5. City of Carlsbad, General Plan, 1966.
6. R.C. Robbins, Stanford Research Institute, Air Pollution Survey
For Expansion of Encina Power Plant (SRI Project 1068); May, 1972.
7. San Diego Gas and Electric Company, Encina Power Plant Unit 5,
Environmental Report; July 1973.
8. San Diego Gas § Electric Company, Application For Construction
and Operation of Encina Generating Unit No. 5 (Application No.
53369); June 1, 1972.
9. U.S. Department Commerce, U.S. Weather Service, "Carlsbad/Palomar,
California Meteorological Data" (unpublished data); September 1973
10. State of California, Division of Highways, District 11, Traffic
Volume on California State Highways 1963- (sic) 1972; undated.
11. Pioneer Service § Engineering Co., State of the Art Report on
Sulfur Dioxide Removal Systems; May 19, 1972.
12. 1970 Census Tracts with Subregional Areas, County of San Diego;
Sept. 1972, San Diego Comprehensive Planning Organization.
13. 1970 Census: Selected Data by Census Tracts, Jan. 1972, Regional
Information System Report Vol. 2, San Diego Comprehensive
Planning Organization.
14. Urban Development Model Forecasts; April 1973, Interpolation
Routine Based on Existing Trends, San Diego Comprehensive
Planning Organization. -••..,
53
15. State of California, Public Utilities Commission, Draft
Environmental Impact Report for Encina Power Plant Unit 5 1
(Application 53369); September, 1973. J
J
J
J
APPENDIX A
..CITY OF CARLSBAD
ORDINANCE NO. 9279
1
.
2 AN ORDINANCE OF THE CITY OF CARLSBAD, ADOPTING
A SPECIFIC PLAN ON APPROXIMATELY 680 ACRES OF
ORDINANCE NO. 9279
LAND LOCATED EAST OF THE PACIFIC OCEAN AND
SOUTH OF THE NORTH SHORE OF THE AGUA HEDIONDA
LAGOON, SUBJECT TO A PORTION OF SAID PROPERTY
BEING ANNEXED TO THE CITY OF CARLSBAD. •
3
4
5
6 ,The City Council of the City of Carlsbad, California, DOES
7 ;: ORDAIN that a Specific Plan for the hereinafter described real
8 I|! property be adopted in the following particulars:
j| SECTION 1. PROPERTY DESCRIPTION. A Portion ofLot F of
10 :!; Rancho Agua Hedionda in the County of San Diego and a Portion of
lliii! Lot H, Rancho Agua Hedionda Map 823, in the City of Carlsbad, and
12 |
I a Portion of Block "W" of Palisades No. 2, Map 1803 in the City of
13 ; ' '
i! Carlsbad, County of San Diego, State of California; also being14 ij
P Parcel 6, Page 07, Book 206; Parcels 24,25,26, and 27, Page 01,
15 || .:..,.
j Book 210; Parcel 21, Page 21, Book 211, and Parcel 14, Page 01,
16
Ii Book 212, of the Assessor's Map of San Diego County, and more
17 i
I particularly described in application on file in the Office of the
18 i
City Planner.
19 '
i SECTION 2. GENERAL CONDITIONS. The Specific Plan, attached
20 !
! hereto, is subject to the following conditions and restrictions:
21 j
! 1. That the granting of the requested zoning shall be sub-
22 j
ii ject to the remainder of the San Diego Gas and Electric property
23 j:
.!i (portion Lot "F") being annexed to the City of Carlsbad. Also
24 i;
!! that the area designated on the Specific Plan as "Site of Future
25.
' Power Plant", east of the freeway, be subject to Specific'Plan
26 i approval at a later date.
•27 ji
i: 2. All developments within the public utility zone shall
281;
','• be within the conditions specified therein and following.
29!;
!i 3. Details concerning the leasing of park lands shall be
30 j;'
|; agreed upon between San Diego Gas and Electric Company and the
31':
i City within one year after the City has approved final rczoning.
32 ;:
ii Location of baseball little league park and sther .athletic
2
3
4
5
6
7
B
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
•27
28
29 i.i
I'
30 !:
r
31 i
I32.;
facilities shall be subject to specific plan approval at the
earliest practicable date, it being understood that the present
proposed location thereof is disapproved.
4. All buildings shall be subject to architectural review
as prescribed in Ordinance Mo. 9268 prior to issuance of a building
permit to assure a maximum amount of design compatibility with the
neighborhood and existing facilities.
5. The heights of future power generating buildings and
transmission line tower structures shall be of heights and of a
configuration similar to'existing facilities. All storage tanks
shall be screened from view. No other structure or building shall
exceed thirty five (35') feet in height unless a specific plan
is approved at a public hearing.
6. All fuel storage tanks shall be recessed and used for
those oils which, upon being consumed, shall not have a sulphur
content exceeding .50 percent; being that percentage commonly
associated with the term "low sulphur fuel oil."
7. Landscape and irrigation plans prepared by a registered
landscape architect shall be submitted in conformance with Ord-
inance No. 9268 for the screening of existing facilities. Plans
shall be submitted within two years and must provide a schedule
for i ns tal1ati on.
8. That the proposed site for a future power generating \
facility on the East side of Interstate 5 shall be planned so as to;
be compatible with the present facility. The facilities shall meetj
I
the requirements of the State and Federal regulations and shall be :
!
environmentally compatible with the City of Carlsbad.
9. All signs shall be in conformance with City ordinances
within 90 days.
10. Exterior lighting shall be oriented so that adjacent
properties shall be screened from glare or a direct light source.
-2-
J
J
J
J
Ijj 11. Prior tc any construction, detailed plans shall be sub-
ii2i mitted to the City of Carlsbad Fire Department to assure:
5
13
14
15
16
17
18
19
20
21
22
25
26
•27
28
29
a) Necessary fire protection requirements.
b) Suitable access roads for fire fighting purposes.
Necessary yard mains and fire hydrants.
Other fire protection devices or appliancesdeemed necessary.
6|j 12. That the applicant dedicate right-of-way for that portion
7j' of the width of Cannon Road (1021 R/W) which falls within therII
8j applicant's property East of 1-5. The alignment shall be subject
9 j| to the approval of the City Engineer and Planning Director.
101 13. That the follov/i-ng conditions of public improvements for
11 il Cannon Road and Carlsbad Boulevard be complied with:
12 ii A. Carlsbad Boulevard.
1) Construct street improvements including curb, gutter
sidewalks, street lights and up to 20 feet of paving
along each side where SDG&E property has frontage,
excepting public beaches and property dedicated for
public parks. Construction may be deferred until
mutually agreeable to the City and the Company
except that the safety of the .driving and walking
public will be considered. The improvements may be
financed by assessment district.
Cannon Road.
1) Construct full street improvements for 1/2 street
from Carlsbad Boulevard to a point approximately
600 feet easterly of 1-5 .along frontage owned by
SDG&E, timing to be subject to -approval of City,
but in any event not before development of property
adjoining the south side of Cannon Road or the
institution of an assessment district.
23|; 2) Dedicate full right of way (102 feet) for that
!; portion of Cannon Road easterly of 1-5 which falls24" within SDG&E property.
3) Construction of improvements easterly of B-l may .
be deferred until property easterly of 1-5 is devel- ;
oped. Agreement on grade development and spreading :
of construction cost shall be mutually agreeable to i
the City and the Company. The City policy for improv.-
ement of such streets shall be considered. jI
C. Access roads shall' be subject to City approval. j
': SECTION 3. ADMINISTRATION AND ENFORCEMENT. The Building
OO ; ' ~~~ :
,-, ]' Department shall not approve any structure until such time as the
,0
; Planning Director has certified that all conditions of this
d*+ ',
j| Ordinance have been satisfied.i;
i -3-
2:i
3;!
',,4i;s;1
6
7
8
9
10.
Ill;
t.'
12 i|
13 [
J.*i ,
15 !
16
17 i
18
19
21 jj11
23:;
J-
23:
24 i;
26
•27 ,
|:
28.
i
29'
30:.
31 i
The Planning Director of the City of Carlsbad is designated
as the enforcing officer of this Specific Plan. His decision shall
be final as to whether the subject property has been properly
developed and improved. However, the owners of the subject
property may appeal to the City Council any decision of the
Planning Director relative to this Specific Plan. Such appeal
shall be in writing and filed with the City Clerk within 10 days
following the receipt of the decision of the Planning Director.
The Council's decision shall be final.
INTRODUCED AND FIRST READ at a regular meeting of the City
Council of the City of Carlsbad, California, held on the 20th day
of July, 1971, and thereafter PASSED AND ADOPTED at a regular
meeting of said City Council on the 3rd day of August, 1971, by
the following vote, to wit:
AYES: Cmn. Dunne, McCom'as, Jardine, Castro and Lewis.
NOES: None.
«
ABSENT: None.
DAVID M. DUNNE, Mayor
ATTEST:
KARpJSET E. ADAM'S/ City CTerk
(SEAIT)
-4-
J
J
J
J
.: .. APPENDIX B
AMBIENT AIR QUALITY STUDY
AMBIENT AIR QUALITY STUDY
FOR THE
Prepared for
SAft! DIEGO GAS & ELECTRIC COMPANY
BECHTEL POWER CORPORATION
LOS ANGELES DIVISION
July. 1973 Amendment 1
1. INTRODUCTION
The impact of the expanded Encina Power Plant on ambient air quality was
estimated during the preparation of the Environmental Report for Encina
Unit 5. It was determined that, with the existing stack height, the
emissions from Units 1 through 5 would cause ground-level sulfur dioxide
concentrations in excess of the ambient air quality standards. Since the
Environmental Report was published, the impact of the Encina Power Plant
on ambient air quality was studied by Bechtel and its consultant,
Systems, Science, and Software. This effort was directed at determining
the plant stack height modifications required to maintain air quality near
the Encina Power Plant within applicable standards. The purpose of this
report is to summarize the results of that study.
July 1973 5A.1-1 Amendment 1
2. SUMMARY AND CONCLUSIONS
To maintain ground-level concentrations of emissions from the Encina
Power Plant within the ambient air quality standards promulgated by
the U.S. Environmental Protection Agency (EPA) and the State of California
Air Resources Board (ARE), it is recommended that flue gas from all five
boilers at Encina be discharged to the atmosphere through a single stack,
400 feet above mean sea level (MSL). By discharging through a single stack
rather than five separate stacks, higher plume rise and lower ground-level
concentrations can be achieved. At many power plants the flue gases from more
than one boiler have been combined into a single stack. At one power plant
a single stack was designed to handle the flue gas from eight boilers in
(2)order to improve air quality.
Table 5A-1 summarizes the calculated maximum ground-level ambient concentra-
tions of effluents from the Encina Power Plant assuming flue gas is
discharged through a single stack. Two stack heights, 325 and 400 feet
MSL, and two fuel oils, containing 0.3 and 0.5% sulfur, were considered
in the analysis.
Also shown in table 5A-1 for comparison are the ambient air quality standards
of the EPA and the California ARB^ that are applicable to the Encina
Power Plant. The ARB standards for sulfur dioxide and nitrogen dioxide are
much more stringent than the corresponding federal EPA standards. The
California 24-hour S0? standard and 1-hour NO standard were the limiting
standards for the selection of the stack height for the Encina Power Plant.
(3)In the Federal Register, the EPA ambient air quality standards are
3stated in terms, of both micrograms per cubic meter (ug/m ) and parts per
million by volume (ppm). The EPA has primary standards designed to protect
public health and secondary standards to protect public welfare and property.
The California standards are stated in terms of parts per million in the
(4)California Administrative Code and have been converted to micrograms
per cubic meter in table 5A-1 for purposes of comparison. The reference
conditions used in this conversion are 760 mm Hg pressure and 25C.
July 1973 5A.2-1 Amendment 1
C-i
VO
Table 5A-1
CALCULATED MAXIMUM GROUND-LEVEL AMBIENT CONCENTRATIONS OF EFFLUENTS
FROM THE ENCINA POWER PLANT*
Effluents
Sulfur dioxide
Annual average
24-hour average
.3-hbur average
1-hour average
Nitrogen dioxide
Annual average
1-hour average
Particulates
Annual average
24-hour average
Carbon monoxide
12-hour average
8-hour average
1-hour average
Ambient Air Quality Standards
U.S. Standards
(EPA) (3)
Primary
80 (0.03)
365 (0.14)
100 (0.05)
75
260
10,000 (9)
40,000 (35)
Secondary
60 (0.02)
260 (0.1)
1,300 (0.5)
100 (0.05)
60
150
10,000 (9)
40,000 (35)
California
Standards
(ARE) (*>
105 (0.04)
1,309 (0.5)
470 (0.25)
60
100
12,500 (10)
50,000 (40)
Calculated Maximum Ambient Concentrations
Due to Encina Emissions (Excluding Background)
325-ft MSL Stack
0.3% S oil 0.5% S oil
21 (0.008) 35 (0.013)
55 (0.021) 92 (0.035)
289 (0.110) 482 (0.184)
434 (0.166) 723 (0.276)
22 (0.012)
449 (0.239)
8
22
5 (0.004)
5 (0.004)
38 (0.033)
400-ft MSL Stack
0.3% S oil 0.5% S oil
18 (0.007) 30 (0.011)
44 (0.017) 73 (0.028)
241 (0.092) 402 (0.154)
361 (0.138) 602 (0.230)
19 (0.010)
374 (0.199)
7
18
4 (0.003)
4 (0'.003)
31 (0.027)
O;
Isj
(D
CL3n
*Calculated assuming full load, 0.3 and 0.5% sulfur fuel oil, single stack for all units. Units are
in micrograms per cubic meter (pg/m3); corresponding parts per million (ppm) values are shown in parentheses.
SUMMARY AND CONCLUSIONS
The concentrations given in table 5A-1 are the maximum expected increase in
the background concentration due to the operation of the Encina Power Plant.
Ambient ground-level concentrations of effluents from the Encina Power
Plant will vary with direction and distance from the plant and with time of
the day and time of the year. The concentrations given in table 1 are
determined for the place and time that maximize the ground-level concen-
tration.
With a 400-foot MSL stack, the maximum ambient concentrations of sulfur
dioxide, nitrogen dioxide, particulates, and carbon monoxide are well
within the standards. Particulate and carbon monoxide concentrations will
be very low. When 0.5% sulfur oil is burned, the maximum 24-hour average
3
SO. concentration is calculated to be 73 yg/m , which is 70% of the Cali-
fornia standard and 28% of the EPA secondary standard. When 0.3% sulfur
fuel oil is burned, the maximum 24-hour average S09 concentration is
3 *
calculated to be 44 yg/m , which is 42% of the California standard and
17% of the EPA secondary.standard. The maximum 1-hour average N09
3concentration is calculated to be 374 yg/m , which is 80% of the California
standard, based on the very conservative assumption that all of the nitrogen
oxides emitted are in the form of nitrogen dioxide. This is conservative
since typically 90% of the nitrogen oxides emitted from a power plant is
nitric oxide (NO) and conversion of NO to NO- in the atmosphere usually
requires more than an hour.
With a 325-foot MSL stack, the maximum concentrations would be corres-
pondingly larger. The maximum 24-hour average SO concentration in this
*• 3
case when 0.5% sulfur oil is burned is calculated to be 92 yg/m , which
is 88% of the California standard and 35% of the EPA secondary standard.
If 0.3% sulfur fuel oil is burned, the maximum 24-hour average SO concen-
•i ^
tration is 55 yg/m , which is 52% of the California standard and 21% of the
EPA secondary standard. The maximum 1-hour average NO concentration is
3calculated to be 449 yg/m , which is 95% of the California standard, based
again on the conservative assumption that NO to NO conversion is complete
at the downwind distance at which the maximum concentration exists.
July 1973 5A.2-3 Amendment 1
SUMMARY AND CONCLUSIONS
The background concentrations of pollutants in the vicinity of the Encina
Power Plant due to sources other than Encina are expected to be small since
the location is distant from large pollution sources and since the prevail-
ing sea breeze carries clean air from the ocean past Encina. This assess-
ment has been verified by a limited number of measurements made by the
Stanford Research Institute. Five measurements of ambient sulfur
dioxide concentrations were made a short distance upwind of Encina during
1971 and 1972. The five 20-minute samples give concentrations ranging from
0.006 to 0.016 ppm and averaging 0.009 ppm. Nine measurements of back-
ground ambient nitrogen dioxide concentrations were made upwind of Encina
for 20-minute periods, yielding values between 0.004 and 0.028 ppm and
averaging 0.013 ppm.
July 1973 5A.2-4 Amendment 1
3. DISCUSSION
Flue gas emitted from a power plant stack rises due to its upward momentum
and buoyancy, is transported horizontally by the winds, is dispersed by the
turbulent eddies present in the atmosphere, and is gradually diluted by
mixing with the ambient air. As a result of the elevated release, plume
rise, and downward dispersion, the ground-level pollutant concentration at
a typical power plant varies from nearly zero directly under the stack, to
a maximum 1 to 5 miles downwind, and back down to nearly zero several miles
from the plant. In the Encina Unit 5 Environmental Report, the commit-
ment was made to design the Encina Power Plant so that the ground-level
concentrations are within the ambient air quality standards promulgated by
all levels of government. The effect of the Encina Power Plant on air
quality was studied to determine the plant stack modifications necessary
to maintain acceptable air quality with the plant expansion to 924 MW.
Three factors, specific to the Encina Power Plant and its location,
required special attention in order to determine a stack configuration and
height that would disperse flue gas adequately and maintain ground-level
ambient air quality within the standards. These factors were:
• Aerodynamic downwash
• Inversion-limited mixing
• Sea breeze effects
The power plant building with its.long axis perpendicular to the prevailing
sea breeze is a large obstacle to air flow and therefore displaces stream-
lines and causes a large turbulent region downwind of the building (figure 5A-1),
If the plant stacks are not sufficiently high, flue gas emissions will be
caught in the aerodynamic downwash behind the building and will be mixed
rapidly to the ground, causing excessively high ground-level concentrations
(figure 5A-2).
Ambient air monitoring conducted by Stanford Research Institute and
computer mathematical modeling studies performed by Systems, Science, and
Software have shown that, with the existing stack configuration and height
at the Encina Power Plant, downwash and high concentrations occur near the
July 1973 5A.3-1 . Amendment 1
DISCUSSION
power plant. Systems, Science, and Software's computer codes solve the
basic differential equations governing the flow and diffusion of fluids and
gases in two and three dimensions with the use of the finite-difference
approach. These codes are useful for determining ambient concentrations
from a source when downwash and other irregular flow conditions exist.
Figure 5A-3 shows in a computer-drawn form a vertical cross-section of a
plume from the existing Encina Power Plant with 190-foot MSL stacks and a
sea breeze of 5 meters per second (11 miles per hour). Sulfur dioxide
concentrations are indicated by the numbers and blank areas between the
numbers; the larger the number, the higher the concentration. A
significant downwash can be observed downwind of the building. Although
the computer drawing is not to scale (i.e., the horizontal scale is com-
pressed relative to the vertical scale), the plume can .be seen being pulled
down into the building wake (shown schematically in figure 5A-2).
The ground-level sulfur dioxide concentrations corresponding to a 5-meter-
per-second sea breeze and Units 1 through 3 operating with the existing
stacks (190 feet MSL) at full load on fuel oil containing 0.38% sulfur are
shown in figure 5A-4 as a function of distance downwind from the power plant.
Note that as a result of the downwa-sh behind the building, the sulfur
dioxide concentration reaches a maximum of nearly 800 micrograms per cubic
meter approximately 0.4 kilometer downwind. At a mile (1.6 kilometers)
downwind, the concentration has dropped off to approximately 100 micrograms
per cubic meter, which is significantly larger than the concentration that
would be expected if downwash conditions were not present. These computer
results were substantiated by the ambient monitoring done by Stanford
Research Institute in 1971 and 1972. During a 5-day monitoring period
in August 1972, the sulfur dioxide concentration measured 1 mile east of
the plant consistently reached peaks for 2 or 3 hours in the afternoon of
3
approximately 0.08 ppm (200 yg/m ).
To eliminate downwash, stacks can be raised so that the plume is removed
from the disturbed flow region. A general rule-of-thumb states that a
plant stack must be 2 to 2.5 times the building height to be out of the
influence of the downwash effects. ' This was verified by wind
July 1973 5A.3-2 Amendment 1
DISCUSSION
(o g\
tunnel studies and experience at operating plants. ' ' A 325-foot MSL
stack is 2.5 times the existing building height, and the 400-foot MSL
stack is 3 times the existing building height. If a 24-foot esthetic
wall extension is built on top of the existing building, the 325-foot MSL
stack will be 2 times the new building height and the 400-foot MSL stack
will be 2.5 times the new building height. Computer modeling studies
verify the "2 to 2.5 times building height rule-of-thumb" and show that
when the flue gas from Encina Units 1 through 5 is discharged from a single
stack, 325 or 400 feet MSL, the plume is not caught in the downwash as is
the case with the 190-foot MSL stacks.
However, downwash is not the only consideration at Encina. In southern
California, the subsidence inversion traps emissions below it, thus limit-
ing their dilution (figure 5A-5). This trapping effect is the principal
reason for California's severe air pollution problems. The inversion base
. height or mixing depth, the height above ground to which pollutants can
mix, is frequently limited to 1000 feet or less in southern California.
A power plant has an advantage in that emitted flue gases may have suf-
ficient buoyancy to rise into (and even through) the elevated inversion.
There is some critical inversion height that just traps the flue gas
emitted from a power plant and causes the highest ground-level concentra-
tions. An inversion base below the critical value will be penetrated by
the power plant plume. An inversion base above the critical height traps
the plume but provides somewhat more dilution than the critical inversion.
The critical inversion height/is a function of the stack height and the
plume rise. The /^ri^ic^Linversion_heighti can be increased and ground-
level concentrations correspondingly reduced/fbyj increasing the stack- height
and/or by enhancing plume rise. By combining the flue gas from the five
boilers at Encina into one stack, a significant enhancement of the plume
rise can be effected. [Since plume'rise \decreases with increasing wind
speed, the critical inversion height also decreases with wind speed. The
critical inversion height at Encina, with Units 1 through 5 operating at
full load and discharging through a single 400-foot MSL stack, ranges from
536 meters (1760 feet) at a wind speed of 2.5 meters per second (5 miles
per hour) to 221 meters (725 feet) at a wind speed of 10 meters per second
July 1973 5A.3-3 Amendment 1
DISCUSSION
(22 miles per hour). With a single 325-foot MSL stack, the critical
inversion height is 75 feet lower, ranging from 513 meters at the 2.5-
meter-per-second wind speed to 199 meters at the 10-meter-per-second wind
speed.
In addition to downwash and the limited mixing, the persistent and relatively
strong sea breeze limits the plume rise and transports gases within a rela-
tively narrow sector downwind. This wind direction persistence causes
higher 24-hour average concentrations than would occur a-t most inland
sites, where wind direction is more variable. As a result of the persis-
tent westerly winds, areas to the east of the plant will experience the
highest long-term concentrations of effluents from the Encina Power Plant.
The concentrations shown in table 5A-1 were calculated using mathematical
models for plume rise and dispersion ' developed by the Tennessee
Valley Authority (TVA) from measurements taken at several of their power
plants. With emission rates of sulfur dioxide, nitrogen oxides, particu-
lates, and carbon monoxide based on burning fuel oil with a sulfur content
of 0.3 and 0.5% and reZ^asir.g flue gases from a single stack, 325 and
400 feet MSL, the corresponding ground-level concentrations were calcu-
lated for the range of meteorological conditions expected at the Encina
Power Plant. The concentrations shown in table 5A-1 are based on the highest
emission rates and the worst meteorological conditions from a standpoint
of atmospheric diffusion.
Figure 5A-6 shows the 1-hour average sulfur dioxide concentrations as a func-
tion of downwind distance from the Encina Power Plant for two different
meteorological conditions: neutral and limited mixing. Neutral refers to
an atmospheric stability typical during the daytime when the subsidence
inversion is not present. During neutral conditions, flue gas diffuses
without being limited by stable layers of the atmosphere. When an elevated
inversion is present at the critical height that maximizes the ground-level
concentration, the ground-level concentration is increased to those shown
by the curve designated "limited mixing". With an inversion lower than
the'critical height, the plume penetrates the inversion and does not reach
the ground until it is much more diffused and the ground-level concentra-
tions are lower than those given for "neutral". If the inversion is higher
July 1973 5A.3-4 Amendment 1
DISCUSSION
than the critical height, the plume is still trapped; however, the layer
in which the plume mixes is deeper and the ground-level concentrations are
correspondingly lower. In these cases the ground-level concentrations are
between the curves shown in figure 6.
Figures 5A-7 and 5A-8 show the highest ground-level concentration of sulfur
dioxide as a function of wind speed with 325- and 400-foot stacks, respec-
tively. Note that the ground-level concentration increases with increasing
wind speed because plume rise is inversely proportional to the wind speed.
With strong winds, the plume is bent over and does not rise as high as it
does during light winds. The 1-hour average concentrations shown in
table 1 are the highest concentrations calculated, based on the worst
meteorological conditions and a constant wind.
Concentrations, averaged over a period longer than 1 hour, of emissions
from a single source are smaller than the short-term, 1-hour average con-
centrations. The decrease in average concentration with increasing averag-
ing time results because of wind direction fluctuations over the time
period. Wind direction will slowly fluctuate about an average, and emis-
sions are dispersed over a wider angle than would be the case if the wind
(12)were constant. TVA found that peak-concentrations and 1-hour
averages are more than 1.5 times the 3-hour average observed at TVA power
plants 99% of the time. This peak-to-mean conversion factor of 1.5 was
used to determine the 3-hour averages shown in table 5A-1.
The long-term averages — 8-hour, 12-hour, 24-hour, and annual — were
determined from a joint frequency analysis of meteorological data collected
in the area. Four years of meteorological data — wind speed and direction
measured at Camp Pendleton and inversion base height measured at Montgomery
Field in San Diego —were analyzed to determine the range of 24-hour con-
centrations that could be expected at the Encina Power Plant. The wind
direction persistence within a 22.5 sector over a 24-hour period was
coupled with the wind speed and inversion height observed during the given
period to determine the maximum 24-hour average concentrations that would
occur if Encina Power Plant Units 1 through 5 were operating at full
load and discharging through a single stack. The maximum 24-hour
July 1973 5A.3-5 Amendment 1
DISCUSSION
average concentrations vary greatly depending on the meteorological condi-
tions observed. The highest concentrations occurred on the days when the
inversion base was near the critical height and when wind direction was
within a 22.5° sector for several hours. Based on an analysis of the worst
days in the four years and the average meteorology in the area, the maximum
24-hour average concentrations were tabulated and their frequency of
occurrence calculated. The concentrations were found to be log-normally
distributed. Based on the data, the curves of Figures 9 and 10 were
obtained.
Figure 5A-9 shows frequency distributions of the maximum 24-hour average
sulfur dioxide concentrations calculated for the expanded Encina Power
Plant, with a single 325-foot MSL stack assuming 0.3 and 0.5% sulfur fuel
oil is burned, versus days per year, on the average, that the given con-
centration is expected to be exceeded. Figure 5A-10 shows the frequency
distributions for the 400-foot MSL stack. If a 400-foot MSL stack is used,
the maximum 24-hour average sulfur dioxide concentration near the Encina
Power Plant is calculated to be 73 ug/m if 0.5% sulfur oil is burned
3
and 44 p g/m if 0.3% sulfur oil is burned, which will be exceeded
1 day per year on the average. The corresponding concentrations for the
3
325-foot MSL stack are 92 and 55 pg/m , respectively.
The median maximum 24-hour average SO concentrations are also indicated
in the figures and are considerably lower than the maximum values indicated
above. With a 400-foot MSL stack, the median maximum 24-hour SO^ concen-
o 3tration is 30 yg/m if 0.5% sulfur oil is burned and 18 pg/m if 0.3%
sulfur oil is burned. With the 325-foot MSL stack, the median concentra-
tion is 35 pg/m3 if 0.5% sulfur oil is burned and 21 yg/m3 if 0.3% sulfur
fuel oil is burned. The median maximum 24-hour average concentrations
east of the Encina Power Plant are equal to the maximum annual average
concentrations.
July 1973 5A.3-6 Amendment 1
REFERENCES
1. Encina Power Plant Unit 5 Environmental Report, San Diego Gas &
Electric Company, 1972.
2. Palieps, J. R. and Billings, D. G., Single Stack Design for 8-Unit,
1200-MW Power Station, ASME paper 72-Pwr-8.
3. "Environmental Protection Agency Regulations on National Primary
and Secondary Ambient Air Quality Standards," Federal Register,
36 FR 22384, November 25, 1971.
4. "California Air Pollution Control Regulations," California
Administrative Code, Title 17, Public Health Part III; Chapter 1,
Air Resources Board; Subchapter 1, Air Basins and Air Quality
Standards; Paragraph 70200, July 28, 1972.
5. Systems, Science, and Software letters to Bechtel Power Corporation
dated: •; ••
a. January 8. 1973
b. January 29, 1973
c. March 27, 1973
d. March 29, 1973
6. Faith, W. L. and Atkisson, A. A., Air Pollution, Wiley-Interscience,
1972.
7. Lund, H. F., Industrial Pollution Control Handbook, McGraw-Hill, 1971.
8. Evans, B. H., "Natural Air Flow Around Buildings," Texas Engineering
Experiment Station Report 59, 1957.
9. Slade, D. H., Meteorology and Atomic Energy 1968, U.S.A.E.G., 1968.
10. Briggs, G. A., Plume Rise, U.S. Atomic Energy, 1969.
11. Carpenter, S.B. et al., "Principal Plume Dispersion Models: TVA Power
Plants," APCA Journal, Volume 21, Number 8, August 1971.
12.- Montgomery, T. L. et al., The Relationship Between Peak and Mean SC>2
Concentrations, unpublished draft.
July 1973 5A.3-7 Amendment 1
(-•
VJ
l-«
vO
u>
UNDISTURBED FLOW
AGUA HEDIONDA
LAGOON.!
Figure 5A-1
ATMOSPHERIC FLOW CHARACTERISTICS WITH A SEA BREEZE AT THE
ENCINA POWER PLANT (ELEVATION LOOKING NORTH)
• et-'
VJ
u>
REGION OF HIGH CONCENTRATION
DOWNWASH
(D3
8-n>3
Figure 5A-2
TYPICAL BUILDING WAKE DOWNWASH AT EXISTING ENCINA POWER PLANT
WITH 190-FOOT MSL STACKS (ELEVATION LOOKING NORTH)
vO~JGJ
na
Q.
m3
STACK-
oooccoccccoooococoocoooccooccoooaaocsc'. ;-CCCCGuCOOOOOCCCOOOOCOCCOOOaQOOCOCOGGOOOOQOOCOOOOOOOCOCOOOO
OCOCOtuOCOCOOCOGnOCOlOOOCOOoCOOOOCOOCOOOOOOOOOOOOOOOOGGCOOO
CYCLE • 100
e.;::
e.
c-.
c:
o:e;
- c:o:
c:c;c:c:c:
o:c:
oo
c:o:
C:
o:
c:c;::c:t:'5C':c3CC3C3030o~0330&i,oooooooo3oooJoo
111
I 2222
TIME -464.000 SEC
I I I I
till
oouoooocooo33Qoc30c;ocoocoococoL)coac;:oojaocjl:c.3u9sjC.c3j;w
ie:3C023C,3003C'*C3COLUOiJu003C03'10000300eOOoOOOO oocooooooo
000000000
c;::;:;::c::oc:croo:c:oODOOubQOuooooao
mm
lit
Illll
III II
I I I
222222
C3CCc::cT:rooo;ocGOcoc:cooouc.oGOOO I'l 22222222o:::c:t:-;::ococ3CG333C';coGOouOO in 2
II 222 22
II 222 33 22 I I I [I
o:o:c:co3o:osoi:ocjoooc;oo 11 2222 33 2 ii|i
C2 - -CCCCr£CG3C3CC30033CO 12 22 33 22
OCC3o:r03C:300C300003030 2 1 33 333 22o::::cco3o:o'}3:cccoGcoaoi 3s i 3 33 222
o:3::3C"C2033cocoooo I 2 3 333 2222c:3SD3C33c:o:oc3coo 11 22 ' 222*222
c&oocaoc-o:ocoooooo u 22 2222 22203c:occ3':3:ooGooo i 22 33 22 22222 222orcocccosccoso i 23 H t 33 2222 222o:::c:c3:ccco i 3t s 5 i 3 222 1
o:c:::cc:cco 12 is * * i 33 2222 I
CC3033C333CO 31 S 6* 513 2222 ' II
OCOC3CC33CCOI »' »* S 1 3 22 111
OOCOCG?30C)3034»8 45< 3 2 Illllllll
0:03C30330CO t _»n » 5 11 3J 22 I I I I I I I I I I
333 22 U I I I I I I I
222222 III
I 1111 II I
HI
I
I I
II
I I
II
111
'"Ijllll
1111)1111
111
I
I
I
I 1 1II I1 1II
III
00000000
;.C3
j: 3 3
OJOO
CCC3
O'.CO:c30
JC30
J330o;30
liltmillmill1 1 1
OGOOOGOOC0003COOCCOCCUOa03CiC:":CjCC033SC:CjL':u330-.:33C33
000000003300000GCCC000030GCOCJJ330C330CCCOoJOUC3C;;;3i:j;3
0000000030000000aCCOC0030aOOOOJ00300JOCJU(JjuOuuOOjUu3CO;0
000000003C3COOOOCOCOOOOOC00000030CCOCOCJ3COJ3C,G33J3l.C3a;0
OOCOOOG33CCO II
000300C330:C3000(j
003CC3COOCC00300tOOobo:ccoo;33c:ooooocooo30000
OOOCOCC33CC03COOCOOOJOOOOOOO
OOC:33C03j303300COOO)0000000000000
• c:: c 3 c c 3 o: o 3 o as ItOOOOQOOOOOOO
000000000000003000C003JC3000000C030303GOOOJOCGi,OJ3jJC33033
I ' (300U0000000003030COCGOOOOOOOC03C030030COJCOC33UOJOCJJJCJ30
I 00000000033 3 03033r;C333GCOC03003C33C333331J 30 Ju3uOO:jOJ3Ci;30
1 OOOGOa000300033000G0303C0000003uGCOJ3300uGOjJOUOLlJJCibOOJ30
I OOOOOOOOOOOOOOOOOOGCOG030000000000030030002000COOGiJJi:33:030
I OOOOOOOOOOOOOOOOOSOOOOOOCOOOGOOOOOOOOGOOOOOOOOCLIOO JdOO JOOuiJLOOO JO
I I OOOOOOOOOOOOOOOCOOOOOOOOOOCOOCOOCOOOOOOOOCOOOOOOOOOOCOOOOOJOj3:000
0000000000000000000033000COOGCOOOOOu003i)OOOOOOJG3jOOOOCl/OJUJuaJ3030
000000000000000000000000003000000000000000330000GOOOOOQOOOjOOU03CaG3
COOOOOOGOOOOOOOCOOOOOOOOoOOOOC0030000COOjOOC0300033COOGOUOuOUi;Ju[,330CO
00000300COOOOOOOCOGOOOOJC000000000000000003030000000000000000000000C00030
00030000000000000000000000000000000000000003000000000000000003000003000
OOOOOOOOOOOOOOOOOOOOOOOOOOOJOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOG000300030
ll~" OOOCOOOOOOOOOOCOOOOOOOOOOOGOOCCDOOOOOOOOGOCOCOOOOGOO'JOOGOuOOOOOCOCGOO
0000000000000000000000000000000000000000000000000000000300000000020030
oooooooooooooooooooooaooooooooooooaoocGooaoocoo3o3aoooccoooouooooouuooooco3ooo
OoOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOC030000000000003000000000000303000000CDOO
OOOOoCOOOOOOOOOOOOOGGOOOOOOOO 3000000000 30003 3000000 30 COOGOOOOOOOOOOOOOOOaOuOOOJOOOOOOO
OOOoOOOOOOOOOODPOOOOOOOOOOOOU0003GOOOOOOOOOOOOC000000000000030000COOOOOUOu3UUOOOOOOOO
OOo00000000000000000000000030GOOOOOOOOoOOOOOOOOOOOOOOJ000033000000u000300JOOOi3u3d300oocoooooooooooooooooooooooooooooooaoooooooocoocooooooooooooooooooooooooooooooooooooocooooooooooooooooooooooooocooaaooooaooooooooooooooooooooooiioooouooooooooooooooooo
000000000000000000000000000000000000003000000000COC000030000000000000000C0330000
OOC0000000000000000000000000000000300COOGOOOOOOOOOOaOOOOOOOOOOOJOOu0003u30003» .
MINIMUM VALUE - 0.000 MAXIMUM VALUE - 3.944+00
1 MILE * 1609 METERS
Figure 5A-3
CALCULATED VERTICAL CROSS-SECTION OF PLUME FROM
EXISTING ENCINA POWER PLANT WITH 190-FOOT MSL STACKS
.E
o>
ZuiO
o5
K
UJ
6z
oE
O
uiO
c
C
Oz
ui
900
700 -
600
400
300
200
100
NOTES:
, • UNITS 1-3 OPERATING AT FULL LOAD
• 0.38% SULFUR FUEL OIL
• THREE 190-FT MSL STACKS
• WIND SPEED OF 5 METERS PER SECOND
0.2 0.4 0.6 0.8 1.0 1.2
DOWNWIND DISTANCE (KILOMETERS)
1.4 1.6 1.8
Figure 5A-4
GROUND-LEVEL SULFUR DIOXIDE CONCENTRATIONS DOWNWIND OF THE
EXISTING ENCINA POWER PLANT WITH A TYPICAL SEA BREEZE
July 1973 Amendment 1
AVERAGE INVERSION HEIGHT
STABLE LAYER
CRITICAL INVERSION HEIGHT
PACIFIC
OCEAN
PLUME TRAPPED BELOW INVERSION
. AGUAHEDIONDA
^ LAGOON &&£
Figure 5A-5
LIMITED MIXING CONDITION AT THE
ENCINA POWER PLANT
(ELEVATION LOOKING NORTH)
zo
ZUJu
oo
CMO
z3
Otro
UJO
<ocUJ
600
500
400
300
200
oc
D
OI
- 100
LIMITED MIXING
NOTES:
• 400-FT MSL STACK
• 0.5% SULFUR FUEL OIL
• WIND SPEED OF 7.5 METERS PER SECOND
6 8 10 12
DOWNWIND DISTANCE (KILOMETERS)
14 16 18 20
Figure 5A-6
SULFUR DIOXIDE CONCENTRATIONS VERSUS DOWNWIND
DISTANCE AT THE ENCINA POWER PLANT
July 1973 Amendment 1
450 r
BECHTEL CALCULATION. ASSUMING
INVERSION AT CRITICAL LEVEL
LIMITED MIXING
(CRITICAL INVERSION HEIGHT. IN METERS,
IS IN PARENTHESES)
• SINGLE 325 • FT MSL STACK
• 0.3%S FUEL OIL
• EXCLUDING BACKGROUND CONCENTRATION
ESTIMATED EFFECT OF BUILDING WAKE
' S3 CALCULATION
ESTIMATED
CROSSOVER
BECHTEL CALCULATION. ASSUMING
NO BUILDING WAKE
6 8 10
WIND SPEED (m/s)
Figure 5A-7
MAXIMUM 1-HOUR AVERAGE SULFUR DIOXIDE CONCENTRATIONS
DOWNWIND OF THE ENCINA POWER PLANT
July 1973 Amendment 1
400
BECHTEL CALCULATION ASSUMING
INVERSION IS AT CRITICAL LEVEL
NOTES:
• SINGLE 400 -FT MSL STACK
• 0.3% SULFUR FUEL OIL
•EXCLUDING BACKGROUND CONCENTRATION
ESTIMATED EFFECT OF BUILDING WAKE
CALCULATION
ESTIMATED
CROSSOVER
BECHTEL CALCULATION. ASSUMING NO BUILDING WAKE
6 8 10
WIND SPEED (M/S)
Figure 5A-8
MAXIMUM 1-HOUR AVERAGE SULFUR DIOXIDE CONCENTRATIONS
DOWNWIND OF THE ENCINA POWER PLANT
July 1973 Amendment 1
140
CALIFORNIA 24-HOUR AVERAGE SO2 STANDARD
NOTES:
• ERA'S 24-HOUR AVERAGE SO2 STANDARDS ARE
PRIMARY 365
SECONDARY 260 >jg/m3
• BACKGROUND CONCENTRATION EXCLUDED
• SINGLE 325-FT MSL STACK
°£*SULFUR FUEL OIL
0.3% SULFUR FUEL OIL
40 60 80 100 120 140 160 180 200
DAYS PER YEAR, ON THE AVERAGE, THAT GIVEN CONCENTRATION IS EXCEEDED
220
Figure 5A-9
CUMULATIVE FREQUENCY DISTRIBUTION OF MAXIMUM 24-HOUR AVERAGE
SULFUR DIOXIDE AMBIENT CONCENTRATIONS AT THE ENCINA POWER PLANT
WITH SINGLE 325-FOOT MSL STACK
July 1973 Amendment 1
140
2O
<cc
O2
OU
CMO00
cc
UJ
<
DC
3
OI
fl-ew
120
100
80
CALIFORNIA 24-HOUR AVERAGE SO2 STANDARDS ARE:
NOTES:
EPA'S 24-HOUR AVERAGE S02 STANDARDS ARF
PRIMARY 365 ^g/m3
SECONDARY 260 Mg/m3
BACKGROUND CONCENTRATION EXCLUDED
SINGLE 400-FT MSL STACK
05% SULFUR FUFi n,L
«^
0.3% SULFUR FUEL OIL20 -
40 60 80 100 120 140 160 180 200
DAYS PER YEAR, ON THE AVERAGE. THAT GIVEN CONCENTRATION IS EXCEEDED
220
Figure 5A-10
CUMULATIVE FREQUENCY DISTRIBUTION OF MAXIMUM 24-HOUR AVERAGE
SULFUR DIOXIDE AMBIENT CONCENTRATIONS AT THE ENCINA POWER PLANT
WITH SINGLE 400-FOOT MSL STACK
Julv 1973 Amendment 1
APPENDIX C
AESTHETICS PUBLIC OPINION SURVEY
An Opinion Survey
Encina Plant Site Area
Carlsbad, California
SAN DIEGO GAS & ELECTRIC COMPANY
August 17 - 20, 1973
Central Surveys, Inc. Shenandoah, Iowa
TABLE OF CONTENTS
Page
Number
INTRODUCTION
CENTRAL SURVEY'S BACKGROUND AND QUALIFICATIONS
1 ' HIGHLIGHTS OF THE SURVEY
2 SURVEY QUESTIONS AND ANSWERS
DISCUSSION OF SURVEY FINDINGS
5 Awareness of the Proposal
6 Appearance of the Plant
7 Effect of the Plant on Air Quality
9 Four Smaller Stacks vs. One Taller Stack
13 Opinions in Areas of Special Interest
14 Survey Questions and Answers - Areas of Special Interest
SUMMARIES OF VERBATIM COMMENTS
17 Opinions about the Proposed Single Taller Stack
(Q.5-5a)
INTRODUCTION
This report is based on a total of 200 personal interviews with adult
permanent residents of Carlsbad, California. All interviews were made at
respondents' homes by experienced members of Central Surveys' field staff from
August 17th through August 20th, 1973.
Interviews were made in 20 cells or clusters of 10 interviews each.
Starting points for these clusters were street addresses drawn on a randomized
basis from the most recent Oceanside-Carlsbad telephone directory.
The primary purposes of the survey were to measure public reaction to
the proposed changes in the Enciria electric power plant, and to detect any dis-
satisfaction with the present power plant or with San Diego Gas & Electric Company.
A random draw of street addresses would have provided relatively few interviews
in the immediate plant site vicinity, and quite a few at a considerable distance
from the plant, so arbitrary quotas were assigned to specific areas, and street
addresses were drawn from the directory until these quotas had been filled.
The quotas assigned were as follows:
20 interviews (2 clusters) in the residential area
immediately south of the plant site, between Interstate
5 and the coast.
20 interviews (2 clusters) in the residential area just -
"northeast of the Agua Hedionda Lagoon.
110 interviews (11 clusters) in other areas where the
present 4-stack plant is visible, making a total of
150 interviews in the "present visual impact area."
50 interviews (5 clusters) in an area where it is antici-
pated that the proposed taller single stack would be
visible, referred to as the "proposed visual impact area."
In addition to the street addresses chosen from the telephone directory
as the starting points for each cluster of ten interviews, other households were
chosen by use of a counting procedure, allowing interviewers no freedom in the
selection of households for the sample.
#1 - Present Visual Impact Area
#2 - Proposed Visual Impact Area
X - Starting Points for Interview Clusters
CENTRAL SURVEYS' BACKGROUND AND QUALIFICATIONS
Central Surveys has been engaged in public opinion and market research
surveys since 1937. Clients for this work have included more than 300 companies,
individuals, trade associations, and advertising or public relations agencies.
Industries represented include gas, electric, water, telephone, and transit util-
ity companies; baking, brewing, lumber, manufacturing, seed and nursery, banking,
florists, newspapers, magazines, radio and television stations and others.
Approximately 200 public utility companies are among our survey clients.
In addition to corporate clients, Central Surveys has worked in a wide
variety of. elections, state-wide initiatives and referendums, primary and gen-
eral elections of candidates, local franchise elections, bond issues, etc. Al-
though survey purposes in election campaigns usually deal more with campaign
guidance than with predictions, experience in several hundred such elections
has provided frequent test of the accuracy of our personnel and methods.
All material in connection with this study, including sampling and
interviewing instructions, completed questionnaires, code books and data tabu-
lation cards will remain on file at our Shenandoah, Iowa offices.
HIGHLIGHTS OF THE SURVEY
Residents of the Carlsbad area are not particularly aware of the
changes that the company proposes to make in the Encina electric power plant;
fewer than 2 in each 5 say they have heard or read anything about the proposal.
When they are shown pictures illustrating the present appearance of
the plant, and the way it would appear with the planned additions and the single
taller stack, survey respondents favor the proposed new appearance rather than
the present appearance of the plant by a margin of 72 percent to 19 percent.
By 42 percent to 4 percent, they also say they think the proposed plant
rather than the present plant would do the best job in maintaining good air
quality in the area. More than half give neutral answers to this question,
however, expressing no opinions (45%) "or saying the two would have about the same
effect on air quality (9%).
By a margin of 33 percent to 12 percent, survey respondents say they
favor construction of the single taller stack. Most are neutral saying it makes
no difference to them either way (34%) or they are still undecided (21%).
Those favoring the single taller stack usually argue that it would help
improve air quality (23%) or it would look better (20%). Those opposed most
frequently object to the appearance of the tall stack (5%), or express concern
about its cost (3%) or its possible effect on rates (3%).
If they were certain the taller single stack would help reduce ground
level concentration of pollutants downwind from the plant, it appears that 83
percent would then favor it; only 6 percent would be opposed.
SURVEY QUESTIONS AND ANSWERS
NOTE: All percentages in this section are based on the total sample of 200 res-
pondents.
Q. 1: About how long have you lived in Carlsbad? (Only those indicating they are
permanent residents of Carlsbad were interviewed.)
5 years or less 57%
Over 5 to 15 years 24
Over 15 years 19
Q. 2: Have you heard or read about a proposal by San Diego Gas & Electric Company
to remove the four stacksfrom its Encina electric power plant here in
Carlsbad and replace them with a single taller stack?
Yes, have heard or read about this
proposal • 37%
No, or don't recall 63
Q. 3: This picture (handing picture to respondent) shows the expected appearance
of the plant with the present four units. This picture (handing second
picture to respondent) shcr.;s the addition of a fifth unit, the single
taller stack, and an 18 foot height extension to the building exterior to
hide ductwork and additional transmission facilities. Which do you think
has the better appearance?
Present appearance is better 19%
Proposed appearance is better 72
No opinion, no difference 9
Q. 3a: (Asked of those who say either picture has the better appearance) A lot
better, or only a little better?
Present appearance is a lot better 9%
Present appearance is only a little
better 10
Proposed appearance is a lot better 42
Proposed appearance is only a little
better 30
Not asked - express no opinions
on Q. 3 9
Q. 4: Which plant do you think would do the best job in maintaining good air
quality in the Carlsbad area?
Present plant would do the best job 4%
Proposed plant would do the best job 42
No difference, about the same 9
Don't know, no opinion 45
Q. 5: Everything considered, do you favor replacing the four present stacks with
the single taller stack, do you oppose it, or doesn't it make any differ-
ence to you either way?
Favor single taller stack 33%
Oppose it 12
Makes no difference either way 34
No opinion, not certain 21
Q. 5a: Why do you feel that way? Any other reasons?
REASONS GIVEN FOR FAVORING SINGLE TALLER STACK:
; ., Percent favoring (33%)
It would help the environment, reduce air pollu-
tion, there would be less smoke, the smoke.
would blow away better, etc. 23%*
It would look better, have a nicer appearance,
it would be more pleasing esthetically, etc. 20
Electric service would be better, they'd have
more power, new equipment would perform better,
etc. 3
It might be less noisy 3
It would provide jobs, more work for employees 1
Don't know why, no reason 1
REASONS GIVEN FOR OPPOSING SINGLE TALLER STACK:
Percent opposing (12%)
The stack would be too tall and noticeable, it
would be uglier, it would block the view, etc. 5%
It would cost too much, the company would spend
too much money, etc. 3
It would raise rates, customers would have to
pay for it, etc. 3
It would cause air pollution, there would be
more smoke, etc. 2
It's not needed, pollution isn't that bad, etc. 1
Have to halt the growth of the plant somewhere 1
It would cause TV interference 1
*Total exceeds percent asked because some give more than one reason.
Q. 5b: (Asked of all except those who favor the single taller stack on Q.5)
If you knew the taller single stack would help reduce the ground level
concentration of pollutants downwind from the plant even if the plant
were enlarged or if more oil were burned because of a shortage of
natural gas, how would you feel about building the taller stack?
Would favor building the taller
stack 50%
Would oppose it 6
It would make no difference to me, no
opinion, undecided 11
Not asked - favor single taller stack
on Q. 5 33
DISCUSSION OF SURVEY FINDINGS
Awareness of the Proposal
(Q. 2)
For the survey as a whole, 37 percent say they have heard or read about
"a proposal by San Diego Gas & Electric Company to remove the four stacks from its
Encina electric power plant here in Carlsbad and replace them with a single taller
stack."
Replies by most sub-groups are within a few percentage points of this
finding - ranging from 26 percent aware of the proposal among young people in
their 20's and 30's, up to 42 percent among those in their 40's and 50's, as
shown below.
Q. 2: Have you heard or read about a proposal by San Diego Gas & Electric Company
to remove the four stacks from its Encina electric power plant here in
Carlsbad and replace them with a single taller stack?
Number of
Respondents Yes No
(Percentages read across)
Survey Total 200 37% 63
SOCIO-ECONOMIC GROUP:
Well-to-do and upper middle
Lower middle and poor
AGE:
39 or younger
40 to 59
60 or over
SEX:
Men
Women
OCCUPATION OF MAIN WAGE EARNER:
White collar
Retired and widows
Blue collar and miscellaneous
AREA:
Present visual impact area
Proposed visual impact area
113
87
54
91
55
102
98
73
68
59
150
50
41%
31%
26%
42%
38%
37%
36%
40%
34%
36%
38%
32%
59
69
74
58
. 62
63
64
60
66
64
62
68
Appearance of the Plant
(Q. 3 & 3a)
In asking Question 3 (and all subsequent questions), interviewers used
two full-color photographs of the Encina plant. One of these photographs showed
the present appearance of the plant. In the other photograph, an artist had
altered details to show how the plant would appear with the planned additions
and a single large stack.
When respondents are asked which of the two has the better appearance,
they favor the proposed plant with the single taller stack rather than the present
plant by a margin of 72 percent to 19 percent.
Included in the 72 percent favoring the proposed appearance of the plant
are 42 percent who say the appearance is "a lot better" and 30 percent who say it
is "only a little better."
Included in the 19 percent who prefer the present appearance of the
plant are 9 percent who describe it as "a lot better" and 10 percent who say it
is "only a little better."
As shown in the table on the following page, replies to this question
divide almost the same among all sub-groups of respondents. The proportions say-
ing the appearance of the present plant is better range narrowly from 18 percent
up to 20 percent, regardless of income, age, sex, occupation or area. The pro-
posed appearance of the plant is preferred by proportions ranging from 70 percent
up to 74 percent.
Differences in the replies by various groups are too small to be regarded
as statistically significant.
Q. 3: This picture (handing picture to respondent) shows the expected appearance
of the plant with the present four units. This picture (handing second
picture to the respondent) shows the addition of a fifth unit, the single
taller stack, and an 18 foot height extension to the building exterior to
hide ductwork and additional transmission facilities. Which do you think
has the better appearance?
Present Proposed
Survey Total
SOCIO-ECONOMIC GROUP:
Well-to-do and upper middle
Lower middle and poor
AGE:
39 or younger
40 to 59
60 or over
SEX:
Men
Women
OCCUPATION OF MAIN WAGE EARNER:
White collar
Retired and widows
Blue collar and miscellaneous
AREA:
Present visual impact area
Proposed visual impact area
Effect of the plant on Air Quality
Number of
Respondents
200
113
87
54
91
55
102
98
73
68
59
150
50
Appearance Appearance No
Is Better Is
(Percentages
19%
19%
19%
19%
18%
20%
18%
20%
18%
20%
19%
19%
18%
Better
read
72
73
71
72
73
71
71
73
74
71
71
73
70
Opinion
across)
9
8
10
9
9
9
11
7 .
8
9
10
8
12
(Q. 4)
In reply to this question, 42 percent say they think the proposed plant
with the single taller stack would "do the best job in maintaining good air quality
in the Carlsbad area;" only 4 percent believe the present plant would do the best
job in this regard. The remainder includes 9 percent who think there would be
little difference between the two, and 45 percent who express no opinions.
By varying margins, a]1 sub-groups tend to agree that the proposed plant
rather than the present plant would do the best job in maintaining air quality, but
majorities in most groups either express no opinions or say they think there would
be little difference between the two plants in their effect on air quality.
Q. 4: Which plant do you think would do the best job in maintaining good air
quality in the Carlsbad area?
Number of Present Proposed No No
Respondents Plant Plant Difference Opinion
Survey Total
SOCIO-ECONOMIC GROUP:
Well-to-do and upper middle
Lower middle and poor
AGE:
39 or younger
40 to 59
60 or over
SEX:
Men
Women
OCCUPATION OF MAIN WAGE EARNER:
White collar
Retired and widows
Blue collar and miscellaneous
AREA:
Present visual impact area
Proposed visual impact area
(Percentages
200
113
87
54
91
55
102
98
73
68
59 '
150
50
4%
3%
5%.
2%
3%
5%
4%
3%
3%
4%
3%
3%
6%
42
40
46.
48
37
46
46
39
40
41
48
41
46
read across)
9
10
7
6
16
2
11
7
13
6
7
9
10
45
47
42
44
44
47
39
51
44
49
42
47
38
Four Smaller Stacks vs.
One Taller Stack
(Q. 5, 5a, & 5b)
One-third (33%) say they would favor replacing the four present stacks
with the single taller stack, while only 12 percent would be opposed. The remain-
der includes 34 percent who say it doesn't make any difference to them either way
and 21 percent who are undecided.
Those favoring the proposed single taller stack usually argue that it
would be helpful in reducing air pollution (23% of the respondents) or that it
would have a nicer appearance (20%). Smaller proportions say they think the pro-
posed arrangement would help insure better electric service and a more dependable
supply of power, it might reduce noise problems, etc.
The 12 percent opposed to the single taller stack includes 5 percent
who dislike the appearance of the proposed stack, and smaller proportions who say
it would be too costly or that it would lead to higher electric rates, it would
increase rather than decrease air pollution problems, etc.
The reasons offered for favoring or opposing the single taller stack
are shown in verbatim form beginning on Page 17 . It will be noted in these
comments that a number of people have the mistaken impression that the plant im-
provements will be made out of tax monies.
In addition to the 33 percent who originally favor the single taller
stack, another 50 percent say they would favor it if they "knew the taller single
stack would help reduce the ground level concentration of pollutants downwind
from the plant even if the plant were enlarged or if more oil were burned because
of a shortage of natural gas." Six percent still say they would oppose the single
taller stack, and 11 percent remain undecided.
10.
Although most of those opposing the construction of the single taller
stack on Question 5b are people who also opposed it on Question 5, a few are not - •
as summarized below:
66 respondents favor the single taller stack on Q. 5
and were not asked Q. 5b.
23 oppose the single taller stack on Q. 5. Of these,
11 favor it on Q. 5b;
8 continue to oppose it, and
4 are undecided.
69 respondents say the change would "make no difference"
on Q. 5. Of these,
58 favor the single stack on Q. 5b,-
1 is opposed, and
10 are undecided.
42 respondents are undecided on Q. 5. Of these,
32 favor the single stack on Q. 5b;
2 are opposed,, and
8 remain undecided.
Those few who switch from neutral positions to opposition to the plant
after being asked Question 5b apparently do so because they object to the idea
that the plant might be enlarged or that more oil might be burned at the plant.
Tables on the following pages show that opposition to the proposal is
not seriously concentrated in any one sub-group of respondents. The argument
used in Question 5b, regarding the effect of the taller stack on the ground level
concentration of pollutants, is highly effective in winning support for the pro-
posal among all groups of respondents.
11.
Q. 5: Everything considered, do you favor replacing the four present stacks
with the single taller stack, do you oppose it, or doesn't it make any
difference to you either way?
Survey Total
SOCIO-ECONOMIC GROUP:
Well-to-do and upper middle
Lower middle and poor
AGE:
39 or younger
40 to 59
60 or over
SEX:
Men
Women
OCCUPATION OF MAIN WAGE EARNER:
White collar
Retired and widows
Blue collar and miscellaneous
AREA:
Present visual impact area
Proposed visual impact area
Number of
Respondents
200
113
87
54
91
55
102
98
73
68
59
150
50
Favor
(Per
33%
36%
29%
33%
34%
31%
35%
31%
36%
29%
34%
34%
30%
OppO!
cent;
12
15
7
17
13
4
11
12
15
/.*-t
15
10
16
Makes No
Difference
No
Opinion
26
46
24
33
47
43
25
27
49
27
33
40
23
18
26
20
18
11
32
22
18
24
23
14
12.
Q. 5b: (Asked of all except those who favor the single taller stack on Q. 5)
If you knew the taller single stack would help reduce the ground level
concentration of pollutants downwind from the plant even if the plant
were enlarged or if more oil were burned because of a shortage of natural
gas, how would you feel about building the taller stack?
Survey Total
SOCIO-ECONOMIC GROUP:
Well-to-do and upper middle
Lower middle and poor
Number of
Respondents
200
113
87
Favor Oppose
No
Opinion
(Percentages read across)
83%** 6 11
85%
81%
5
6
10
13
AGE:
39 or younger
40 to 59
60 or over
54
91
55
79%
84%
85%
4
9
2
17
7
13
SEX:
Men
Women
102
98
88%
79%
5
6
7
15
OCCUPATION OF MAIN WAGE EARNER:
White collar
Retired and widows
Blue collar and miscellaneous
73
68
59
88%
84%
78%
5
3
9
7
13
13
AREA:
Present visual impact area
Proposed visual impact area
150
50
82%
88%
6
4
12
8
**Figures in this column are the total proportions saying they would favor
construction of the single taller stack, either in reply to Question 5, or
to Question 5b.
13.
Opinions in Areas
of Special Interest
As mentioned in the Introduction, 40 interviews were obtained in areas
of special interest in fairly close proximity to the site of the power plant.
These areas may be described as follows:
Area A (20 interviews)
This is an area located between Interstate 5 and the coast,
south of the plant site. Interviews in this area were made
on El Arbol Drive, Los Robles Drive, Shore Drive, and Tierra
del Oro.
Area B (20 interviews)
This is a residential area located just east and slightly
north of Agua Hedionda Lagoon. Interviews in this area were
made on Alondra Way, Hillside Drive, Sevilla Way, and Valencia
Avenue.
These numbers of interviews are extremely small for separate statistical
reliability. Nevertheless, they are of particular interest because of the possi-
bility that opposition to the present power plant or to the proposed changes in
the plant could easily be concentrated in these areas.
This did not prove to be the case, however. As shown in the comparisons
on the following pages, residents of Area A seem to be more aware of the proposed
changes in the plant, and more in favor of them, than other respondents. Those
living in Area B seem to be about in line with total survey findings.
14.
Survey Questions and Answers
Areas of Special Interest
Q. 2: Have you heard or read about a proposal by San Diego Gas & Electric
Company to remove the four stacks from its Encina electric power plant
here in Carlsbad and replace them with a single taller stack?
All
Area A Area B Others
Number of' respondents (20) (20) (160)
Yes, have heard or read about this
proposal 55% ' 25% 36%
No, or don't recall 45 75 64
Q. 3: This picture (handing picture to respondent) shows the expected appearance
of the plant with the present four units. This picture (handing second
picture to respondent) shows the addition of a fifth unit, the single
taller stack, and an 18 foot height extension to the building exterior
to hide ductwork and additional transmission facilities. Which do you
think has the better appearance?
Present appearance is better 10% 20% 20%
Proposed appearance is better 75 75 71
No opinion, ao difference 15 5 9
Q. 3a: (Asked of those who say either picture has the better appearance) A lot
better, or only a little better?
Present appearance is a lot better - 10% 10%
Present appearance is only a little
better 10 10 10
Proposed appearance is a lot better 45 50 41
Proposed appearance is only a little
better . 30 25 30
Not asked - express no opinions on
Q. 3 15 5 9
Q. 4: Which plant do you think would do the best job in maintaining good air
quality in the Carlsbad area?
Present plant would do the best job - - 4%
Proposed plant would do the best job 60% 30% 42
No difference, about the same 5 15 9
Don't know, no opinion . 35 55 45
15.
Q. 5: Everything considered, do you favor replacing the four present stacks
with the single taller stack, do you oppose it, or doesn't it make any
difference to you either way?
All
Area A Area B Others
Number of respondents (20) (20) (160)
Favor single taller stack 65% 30% 29%
Oppose it 5 5 13
Makes no difference either way 15 30 38
No opinion, not certain 15 35 20
Q. 5a: Why do you feel that way? Any other reasons?
REASONS FAVORING SINGLE TALLER STACK:
Percent favoring (65%) (30%) (29%)
It would help the environment, reduce air
pollution, etc. 50%' 15% 27%
It would look better, have a nicer appear-
ance, etc. . . 30 30 18
Better electric service, more power, more
dependable, etc. - - 4
It might be less noisy, ecc. 20-1
It would provide jobs, work for their em-
ployees • - 5 - -
Don't know why, no reason - - 1
REASONS OPPOSING SINGLE TALLER' STACK:
Percent opposing (5%) (5%) (13%)
The stack would be too tall, uglier, it
would block the view, etc. 5% - 5%
It would cost too much money - - 4
Rates would go up to pay for it, etc. - 5% . 3
It would cause air pollution, more smoke - - 3
It's not needed, pollution isn't that bad,
etc. - - 1
Have to halt growth somewhere . - - 1
It would bother TV reception . 5 - -
16.
Q. 5b: (Asked of all except those who favor the single taller stack on Q. 5)
If you knew the taller single stack would help reduce the ground level
concentration of pollutants downwind from the plant even if the plant
were enlarged or if more oil were burned because of a shortage of
natural gas, how would you feel about building the taller stack?
All
Area A Area B Others
Number of respondents (20) (20) (160)
Would favor building the taller stack 30% 50% 53%
Would oppose it - - 7
It would make no difference to me, no
opinion, undecided 5 20 11
Not asked - favor single taller stack
on Q. 5 65 30 29
17.
Opinions about the Proposed Single Taller Stack
Q. 5: "Everything considered, do you favor replacing the four present stacks
with the single taller stack, do you oppose it, or doesn't it make any
difference to you either way?"
Q. 5a: "Why do you feel that way? Any other reasons?"
(200 respondents in sample)
66 FAVOR_THE SINGLE TALLER STACK. (Some give multiple reasons.)
46 refer to cleaner air, better dispersal of smoke, etc.
22 say, "It would help clean up the environment," "It seems like it would
cause less pollution," "Keeping our air clean," "It's supposed to
reduce air pollution," "From what I hear, it will take out a lot of the
smoke," "It should help the smog problem," etc.
1 adding, "but it will cost a lot more."
1 "Taxwise, it will cost more - but it will
be worth it."
1 "SDG&E is going to pay for it."
1' ""Maybe there'd be less stuff coming out and
landing on my car. Really, we find the plant
a good neighbor. I'd like for you to write
that down. People who don't even live around
here complain about the plant and it doesn't
affect them at all."
12 "There will be more stuff coming out but it will be higher up," "It
will shoot the steam up higher and get it up above the clouds," "I'd
think it would get the smoke concentration up higher and it would be
blown away," "It disperses the smoke higher in the atmosphere," "It's
taller so the smoke wouldn't end up so close to the ground," etc.
1 adding, "I favor it if it doesn't cost me a
lot of money."
1 "The taller stack won't affect this district."
(Respondent lives in residential area immediately
south of plant site.)
8 "It would be easier to control the emissions from just one stack,"
"You can take the smog out easier if you have just one," "It looks to
me like one stack would make less smoke than four stacks," "It would
be better for pollution with just one stack," etc.
1 "It's taller and there's only one so there'll be less white billows
coming out of it."
1 "A newer stack could filter the junk out better."
1 "They thought it would help the odor."
1 "The tall stack might be better ecologically. I oppose extending the
plant, though."
18.
40 refer to the appearance of the plant or stack.
25 say, "Just from the appearance," "It looks better," "I think it would
look a little nicer," "It would be better esthetically," "For beauty's
sake," etc.
1 adding "The only reason I might be against
it is it's an added expense to them and they'd
ask for a rate increase."
6 "It just looks neater," "It looks a lot neater to me," "It's cleaner and
less cluttered," "It presents a cleaner and more balanced appearance," etc.
1 adding, "but does that mean the taxes would
go up? I don't know."
2 "It's newer and more efficient looking" or "I think its appearance is
ever so much more modern."
1 "It just looks pretty."
1 "I think it changes the lines of the whole plant - it's more pleasing to
the eye." .:....
1 "Carlsbad is glowing so much and we're losing our prettinass. This would
improve the appearance of the coastline."
1 "I've seen one at Morro Bay which has the tall stack and it looks cleaner
and not like it's put together out of an Erector set."
1 "Because it has a new appearance."
1 "It hides the ductwork."
1 "I don't like the appearance of it now."
6 refer to improved service, efficiency, etc.
2 say, "They need to enlarge the facilities" or "It's bigger and we need it
for power."
1 "I think it will mean better service."
1 "It will bring more service with the expansion in one way or another. My
husband is Chief Building Inspector for the city and he likes the idea."
1 "Better results. The boilers will have to be changed so they should be
better."
1 "I'd think it would be better with all the newer ingenuity. Newer
equipment should be better."
19.
5 refer to noise abatement, saying, "I don't know but I'd hope it would
help the sound," "I'd hope it wouldn't be as noisy," "Maybe it will
eliminate some of the noise," etc.
1 says it will provide work for employees, commenting, "It keeps those guys
busy down there. My husband works there. I imagine the only ones opposed
to it would be the painters because they'd have to paint it."
1 gives no reason, saying, "I don't know why."
23 OPPOSE THE SINGLE TALLER STACK. (Some give more than one reason.)
9 give esthetic reasons.
1 says, "The esthetics of the four is better than the one taller stack,"
1 "The stack is a little too high and it blocks the view. I like the
smaller flat look. Besides, there's not much smoke that comes out
now."
1 Because it's too high along the coastline. It will catch your eye on
the freeway because it's higher than the transmission lines. I'll
even be able to see it here where I live- They need to work on the
pollution and not on the stack." (Respondent lives on Cainino del
Parque, well south of the plant site.)
1 "Just for esthetic reasons. Being that much taller, it would be less
inconspicuous."
1 "People would notice it more. They're going back to the old time tall
foundry stack that they've been knocking down all over."
1 "It looks like a factory and it isn't good for the landscape."
1 "I oppose any high rise at the ocean - I don't want to obstruct the
view."
1 "I hate to see that great big tall stack. Too many more people would
have to look at the taller stack than can see the smaller stacks."
1 "Because it could be camouflaged better this way."
20.
6 mention the cost of the plant.
4 say, "I don't think they should go to that expense," "It will cost
them a fortune," "It will cost a lot of money," or "It's going to
cost them half a million dollars."
1 adding, "I don't think the pollution is
bad now."
1 "j think they've spent money redoing this one and they want to do
another. They've been working on that since we moved here."
1 "If it's for looks, and that's what I've heard, they should leave it
as it is because this costs them more money."
6 refer to the anticipated effect on races.
4 say, "It will just cost me more money," "They will ask for an addition
to our rates," "Because our gas and electricity will go up again," or
"It's going to add to the rate."
1 "Gas and lights are high enough now and they'll just add more on to us.
We're on a pension and it's rough, SDG&E isn't the one polluting -
it's the automobile. They could develop thermal steam in the Imperial
Valley and atomic power plants."
1 "It will cost us more. I have no idea of its ecological advantages -
the same amount of smoke has to come out."
4 say it.would cause more pollution, commenting, "It looks like it would
emit more pollution because it's so big," "I'd think one large stack would
have more emissions," "I think you'd get more smoke," or "It looks to me
like it would just be a better system for putting out emissions."
3 give miscellaneous other reasons.
1 says, "The plant gives me TV reception trouble and I think the taller
stack would be worse."
1 "Because you have to stop the growth of'the plant someplace - let
them build another plant somewhere else. This would just be an
invitation for bigger industries to build here because SDG&E isn't
getting enough opposition pressure."
1 "I don't see that it's all that necessary.'
21.
69 SAY IT MAKES NO DIFFERENCE TO THEM EITHER WAY.
2 adding, "It's just going to cost more" or
"The new one would raise the rates."
2 "It depends on what it costs us" or "but
I wouldn't like for the rates to go up."
1 "If it raises taxes, no."
1 "since I don't know the facts."
1 "Let them do as they like."
42 ARE UNDECIDED.
22 say, "I don't know," "I couldn't say," etc.
6 "Will it make more stuff in the air?" "Will it help air pollution? If
not, there's no reason in spending all that money," "Would it eliminate
the black belching smoke they sometimes have?" "It depends on which
controls emissions best - I sure don't like the idea of a tremendous
amount of smoke concentrated out of one stack," '"Whichever way is the
cleanest," or "I'm in favor of whatever causes less pollution."
4 "Is it going to cost us?" "I don't know - I'd have to know how much it's
going to cost," "What's it going to cost? If it doesn't increase rates,
the one stack is better," or "It depends on the cost to the power company
and if it raises our rates. I wouldn't push Lor it if it's a terrific
cost to them."
3 "I don't know - would it mean more taxes? If it doesn't, then one stack
is better," "Does it come from taxes? If so, I'd oppose it," or "I'm not
sure because I don't know if it. would increase our taxes."
3 "I'd need more of an in-depth study," "I'd have to know more details," or
"I'd want to know why they considered it."
1 "I'd want to know where the funds are coming from first. It would affect
our electric bills. I'd imagine, so I don't know. It depends on how
much our electric bill would go up."
1 "How much money would it cost me? If it means more taxes for me, no.
If they pay for it and use it as a tax write-off, yes."
1 "I'd want to know the economics and ecological values first."
1 "I don't know. Either our taxes will go up or our gas and electric bill
will go up."
APPENDIX D
FAA STACK STUDY
DEPART
FEDERAL
OF TRANSPORTATION
TION ADMINISTRATION
NOTICE OF PROPOSED CONSTRUCTION OR ALTERATION
1. NATURE OF STRUCTURE (Complete both A and B below)
rm Approved. flud«r< nurr.iu No. 04-ROOfll.
TO_ BE COMrU. E T E D_B_Y_F_AA_
AERONAUTICAL STLOY NO.^
A.(Check one)
DD NEW CONSTRUCTION OALTERATION
^•(Chcck one)
(XI PERMANENT TEMPORARY
(Stale length
of time) 'Max.
2. NAME AND ADDRESS OF INDIVIDUAL, COMPANY. CORPORATION, ETC. PROPOSING
THE CONSTRUCTION OR ALTERATION (*„„<,«. !<«.>. diy. SHI, *,d z,p Cod,)
PSAN DIEGO GAS & ELECTRIC COMPANY ~^
TO p. 0. Box 1831
San Diego, California 92112
ATTENTION:
\__
T. M. Nutt
Right of Way Agent J
FAA WILL COMPLETE ANO PET'jSN Th,3
FORM IF ONE OR MORE OF THE FOLLOWING
IS APPLICABLE, OTHERWISE SEPARATE AC-
KNOWLEDGEMENT WILL BE ISSUED.
A. A STUDY OF THIS PROPOSAL HAS 01 S-
CLOSEO THAT THE PROPOSED STRUCTURE:
PJOOES >IOT REQUIRE A NOTICE TO ?AA.
WOULD NOT EXCEED AUY STANDARD
IJJOF PART 77 ASO WOULD NOT BE A
HAZARD TO AIR NAVIGATION.
SHOULD BE MARKED AND LIGHTED P-.-»
. -_,FAA "OBSTRUCTION MARKING A'O
BflLIGHTING" ADVISORY CIRCULAR
7O/746O-1.
REQUIRES SUPPLEMENTAL NOTICE.
PSNOTICE FORM (FAA FORM II 7-t )
ENCLOSED.
B. COPY SENT TO FCC? [jY£S J<J "O
VIEWIN* OK.F/CER' MLIf^lsy.
DATE
£-3-73
3. TYPE AND COMPLETE DESCRIPTION OF STRUCTURE
Replacement of 4 stacks at San Diego Gas & Electric Company's Encina Power Plant wit I1
a single unit. This includes a 24' facade addition to the generator enclosures to
conceal duct work. The proposed stack will be 52 feet in diameter at the base, 33
feet at the top, and will stand 383 feet above ground level.
4. LOCATION OF STRUCTURE
•A. COORDINATES <T° •«"«'
LATITUDE LONGITUDE
B. NEAREST CITY OR TOWN, AND STATE
Carlsbad, California
33 os I n 117 I 20 08
(1) DISTANCE FROM 4B
10,000+'
(2) DIRECTION FROM 4B
South
.NAME OF NEAREST AIRPORT, HELIPORT, OR SEAPLANE BASE
Palomar Airport
(1) DISTANCE FROM NEAREST POINT OF
4C 15,250+ .
(2) DIRECTION FROMIRPQRTwest
/ W I IX L. V. '
ftortnv
D.DESCRIPTION OF LOCATION Ol: SHE WITH RESPECT TO HIGHWAYS. STREETS. AIRPORTS. PROMINENT TERRAIN FEATURES. E.\-
ISTINC STRUCTURES. ETC. (Attach a hix/way. street, or any athcr appropriate map or scaled drau ing shou ing the relationship of construction
site lo nearest airporl(s>. I/ more space is required, continue on a separate sheet o/ paper and attach to this notice.)
Situated between the Pacific Ocean and Interstate 5, south of the city of Carlsbad.
5. HEIGHT AND ELEVATION (Complete A. B and C to the nearest foot)6. WORK SCHEDULE DATES
A. ELEVATION OF SITE ABOVE MEAN SEA LEVEL
B.HEIGHT OF STRUCTURE INCLUDING APPURTENANCES AND LIGHTING
f'/»-y) ABOVE GROUND. OR WATER IF SO SITUATED
C. OVERALL HEIGHT ABOVE MEAN SEA LEVEL M +- Bl
17.01
383.0'
A. WILL START
June 197^
400.0'
B. WILL COMPLETE
Unknown
7. OBSTRUCTION MARKINGS-The completed structure will ba:YES NO
A. MARKED AS SPECIFIED IN THE FAA ADVISORY CIRCULAR 70/7460-1, OBSTRUCTION MARKING AND LIGHTING
B. LIGHTED AS SPECIFIED IN THE FAA ADVISORY CIRCULAR 70/7460-1, OBSTRUCTION MARKING AND LIGHTING
I HEREBY CERTIFY that all of trie above statements made by me are true, complete, and correct to the best of my knowledge.
8. NAME AND TITLE OF PERSON FILING THISNOTICE ">;* «• ?'•••>
T. M. Nutt
Right of Way Agent
9.UE/ (I.*.*) /
/ • t / s ' f/,,/.// // ., f-' "
//_
10. DAr^EOFSIG/JATURtj 11. TELEPHONE NO. tP,.c.J* »,<*,;. rod,
3 1(714) 232-4252. Ext. 1715
Persons who knowingly and willfully fail to comply with the provisions of the Federal Aviation Regulations Part 77 are liable 10 j finr of
1500 fot .the first offense, with increased Penalties thereafter as provided by Section 902(a> ol ilic rtiiei.i ,V<i«>i«/ii Act of 1953 as amende J. j