Analysis of Thermal Pollution from the Air*

CARL H. STRANDBERG, tPrincipal Investigator,

U. S. Public Health Service Research Grant WP-181,

Sponsoring Institution,General Research and Development, Inc.,

112-A Wayne St., Arlington, Va.

ABSTRACT: Under U. S. Public Health Service Research Grant WP-181,extensive research and study is being conducted to gain a better understandingof the dispersion and diffusion of heated coolant water. Aerial photographicinterpretation techniques are being used, for analyzation of heat-inducedsecondary effects in the aquatic environment.

Preliminary studies have confirmed that, under certain circumstances, largeareas within heated coolant water discharge zones extending from industrialoutfalls exhibit distinctly different tonal characteristics. Correlation data exam­ined to date indicates that the water in these areas is warmer than the surround­ing water mass.

Studies have included extensive analysis of several of the factors which maycontribute to the formation of photographically recorded "secondary" imagery,which can be recorded in the visible and near-infrared regions of the spectrum.

A nalyses were also made of several types of infrared sensors which mayprove suitable for analysis of temperature distribution within the aquaticenvironment.

A concept has been developed for the integration of a non-image-forminginfrared sensor with a camera system, under which the infrared sensor will actas the "triggering" unit, activating cameras when preselected thermal limitssensed in a water mass. On completion of the "Integrated Aerial Sensor Sys­tem," it is hoped that accurate isothermal maps may be rapidly compiled ofsurface waters.

THE THERMAL POLLUTION PROBLEM

AN ESTIMATED 40% of all of the waterrt available in this country at anyone timeis used f:::>r industrial cooling.' Industrial ex­pansion forecasted to take place between nowand 1980 is expected to increase this demand240%. As is recognized, thermal cooling is alargely non-consumptive use of water. Mostof the surface water used for cooling is re­turned to the lake or stream from which itwas taken, carrying with it the heat acquiredin the course of its use.

The impact of heat on the aquatic environ­ment induces many changes. Some of these

may be desirable; some of them may be un­desirable.

Thermal electric power plan ts are thelargest single user of water for cooling. Theyare estimated to use 74.5%2 of the total in­dustrial coolant water demand. Their require­ments in 1959 amounted to over 24TRILLION gallons.3 Thermal electric plants,on the average, heat the coolant water 12 to13 degrees Fahrenheit, before returning it tothe source from which it was withdrawn.

Extensive evaluation of thermal pollutionhas been made in previous studies, largelyassessing of its effects from the standpoints of

* This paper was presented at the 17th Purdue Industrial Wastes Conference, Purdue Univer., \NestLafayette, Ind., May 3, 1962

t Post Office Box 1553, Wheaton Sta., Silver Spring, Md.EDITOR'S NOTE: For the privilege of publishing this paper thanks are extended to Purdue University,

to the Conference for which the paper was prepared and at which it was presented, and particularly toProf. Don E. Bloodgood, Chairman of the Conference.

656

ANALYSIS OF THERMAL rOLLUTIO FROM THE AIR 657

conservation, natural stream purification, andwater loss.

Analysis of the poten tial effects of heat onthe aquatic environment indicate that thereis an urgent need for more knowledge aboutthe effects of thermal pollution.

It is, for instance, recognized that warmingwater increases its capacity for holding cer­tain substances in solution. It is also recog­nized that certain kinds of fish and shellfishare natural concentrators of certain elements.4Some of these may be quite nutritious, othersmay be quite harmful." It therefore logicallyfollows that at least some of the ediblemarine life in heated coolant water dischargeareas may become either more nutritious, or,perhaps, totally ~nfit for human consump­tion. Heated coolant water which will affectone of the areas in which it is hoped thatstudies can be conducted in the future, nearChalk Point, on the Patuxent River, inMaryland, will flow over three large oysterbeds.6 What effect, it is wondered, \\"ill theheated, possibly more mineralized water haveon these oysters?

Several problems have been encountered inprevious studies of thermal poll u tion. A needhas been voiced for better differentiation ofthe boundaries of mixing zones, for instance. 7

Recent studies indicate that some of themore commonly used engineering formulas fOl"forecasting the diffusion and dispersion ofsubstances into flowing water, which havelargely been derived following purely labora­tory studies, may be in error by a factor of 6to 10, when applied to natural streams. 8

From the conservation standpoin t, the po­tentially harmful effects of heat have beenrecognized for several years. rna paper pre­sented before the 8th Purdue IndustrialWastes Conference, in 1953, Dr. Tarzwell,reporting on studies which started in 1931,stated that raising the temperature of a troutstream to too high a level in just one day outof the year rendered that stream unsuitable asa trout stream. 9

In more recent studies, it has been foundthat other types of fish, notably small mouthbass, appear to thrive in warmer water.Studies which are still in progress indicatethat fishing may be materially improved be­low heated coolant water outfalls. Findings todate, made wi th a special thermistorized fish­ing rod in the Potomac,1O indicate that fish ap­pear to prefer the heated water zone ninemonths out of the year. During two of the re­maining months, they appear to prefer thecooler zone; and in the remaining month,they appear to have no preference. In studies

conducted about 30 years ago 111 Iowa, Mr.Harlan, Conservation Consultant to theDivision of Water Supply and Pollution Con­trol, U. S. Public Health Service, found thatcertain species of game fish stopped eating en­tirely when stream temperatures dropped toless than 54 degrees Fahrenheit.

Apparently, the increased biotic activityinduced by the warmer water increases theavailable food supply. This is indicated instudies which have been conducted below theMartin's Creek Pennsylvania Power andLight Company plant, on the Delaware Riv­er near Stroudsburg, Pennsylvania. Thesestudies, being conducted by the Institute ofResearch, Lehigh University,ll report that, onthe average, fish taken from within the heatedcoolant water zone of the discharge area havebeen larger than those taken outside thecoolant water discharge area.

From the standpoint of natural streampurification, the increase in induced bioticactivity appears to speed up purification. Onthe other hand, in increasing the biotic activ­ity, there is a tendency to more rapidly de­plete the existing reduced supply of dissolvedoxygen. In the \\"inter time, however, heatedcoolant water may be very beneficial in natu­ral stream purification. It may prevent icefrom forming in a large section of an otherwiseice-locked body of water, providing an other­wise non-existen t air-water surface for reoxy­genation Figure 1 ill ustrates this beneficialsituation. Heated coolant water from thePotomac Electric Power Company plant atDickerson, Maryland, kept a stretch of waterseveral miles long from freezing in the \\"interof 1960-1961, when the rest of the Potomacwas frozen over for several weeks.

Several water loss investigations have beenmade, principally by the U. S. GeologicalSurvey, and are well reported in the litera­lure.12- 24

In this investigation, efforts are being madeto develop techniques which will facilitate iso­thermal mapping from the air. If these effortsare successful, significant savings in time andmoney may be realized.

In several engineering, topographic map­ping, and geographic study applications,aerial photographic interpretation and aerialphotogrammetric mapping regularly enablesavings of 80% in time, and 40% in money.

Two types of measurement, both of whichmay be quite significant, may be made withextreme accuracy from the air. First, thephysical size and shape of the area within thereceiving waters which are subjected to in­creases in temperature, and second, the abso-

658 PHOTOGRAMMETRIC ENGINEERING

FIG. 1. Dickerson (Maryland) Thermal Electric Plant, Winter, 1960-1961 (Potomac Electric PowerCompany) (Potomac River).

lute and differential temperatures within thewater mass.

Physical measurement of the area actuallysubjected to increases in temperature neces­sitates that, first, a distinct, measurableimage must be formed. Aerial photography,or other forms of aerial sensors may be used.Aerial photography is preferred, because ofgreater geometric accuracy, and higher objectresolution, considering the current state of theart. Special aerial photographic techniquesappear necessary for picturing desired, mean­ingful imagery. The photogrammetric measur­ing techniques which may be used for actuallymaking the necessary measurements them­selves are only slightly different from thoseused in compilation of about 90% of thetopographic maps which are now produced.

Previous improvements in the art-scienceof aerial photography, as they relate to pic­turing water masses, have largely been madein advancing the state of the art for aerialphotogrammetric mapping. They have beendi rected ei ther toward maxi mum penetrationof a water mass, for more accurate analysisand mapping of the bottom, or have beendirected toward minimum penetration of thewater surface, for more accurate picturing ofshorelines and location of inundated areas.The problem presented in this case, however,and in most of the Principal Investigator'scontinuing efforts to develop a rapid, efficient,economical aerial water quality reconnais­sance system to augment ground methods, isto more accurately picture conditions withinthe water mass. Some of the earlier findings,

particularly those directed toward maximumdepth penetration, appear valuable in de­tecting and analyzing thermal boundaries.

Russian studies,25 begun more than 20 yearsago to develop methods for more accuratemapping of off-shore areas, point out severalimportant elements. It must be rememberedthat the principal problem in all photographyis to record differences in object brightnesswith maximum clarity.

Rays of light, which picture objects or con­ditions within a water mass, must travelthrough two different mediums, each havingdifferent refractive indexes, and differentlight absorption and light scattering char­acteristics.

It was found in the Russian studies thatmaximum penetration, that is, minimum ab­sorption, of light in turbid water occurs in theyellow-orange sector of the visible spectrum,in which the wave-lengths of light lie between576MIL and 609MIL.

The Russians also cited several importantaerial photographic fundamentals relating tophotography taken of water masses. Fourfactors are stressed which affect the relativebdghtness of underwater objects. Eachshould be given consideration when planningaerial photographic fligh ts for the picturing ofsub-surface imagery. These four factors are:

(1) Brightness of the atmospheric haze-thelayer of atmosphere between the lens ofthe camera and the surface of the water.

(2) Brightness of the water surface, which,mirror like, reflects the sky.

ANALYSTS OF THERMAL POLL TlO FROM THE AIR 659

(3) B'Yightness of the water layer above theobject to be photographed.

(4) Brightness of tile underwater object.

In addition, consideration must be givento three additional factors in overcomingbrightness image degrada tion. These are:

(5) J1IIeteorological conditions-state of theatmosphere, clouds and wind.

(6) Height of the SUit above the horizon­time of day.

(7) Flight height-the altitude from whichthe photography is to be taken.

It has been demonstrated that, giving dueconsideration to all of these factors, best re­sults, using panchromatic film, are usually ob­tained, when flights are made on:

(a) relatively clear days, under a high, thincloud layer,

(b) from a relatively low altitude,(c) using a normal-angle lens aerial camera,

fitted \I"ith a yellow filter correspondingto a \Yratten 16, preferably also fitted\I"ith a polarizing light filter to reducethe effect of surface "'ave reflections.

High shutter speeds should be used, withcorresponding large relative aperture settings.

Flights should be made in the morning,when minimum haze conditions usually occur,when the sun is not less than 26 degrees, normore then 50 degrees above the horizon, toreduce surface reflections.

The Photogrammetric Branch, U. S. Coastand Geodetic Survey, has been conductingseveral very significant studies26 using aerialcolor film. Giving due considerations to theseveral factors previously cited-except thatthe photographic filtet· used was essentiallyminus-ultraviolet, rather than minus-blue­coverage has been taken which has permittedaccurate photogram metric mappi ng of theocean floor to depths of 70 feet.

H the intent is to more accurately pictureshore-lines, best resul ts can normally be ex­pected using infrared film and filter combina­tions. Infrared energy is normally completelyabsorbed in natural surface waters. There areexceptions, ho,,·ever. In preli mi nary testsconducted by the Principal Investigator, itwas noted that light-toned patterns can some­times be seen in "'ater in which a great deal ofalgal activity is taking place. This has beennoted twice in coverage taken of the PotomacRiver. One light toned streak detected in in­frared photography was subsequently identi­fied as a drain from the Chesapeake and OhioCanal, which follows the Maryland shore ofthe Potomac above \\'ashington, D. C.

Complete absorption of light in the 576­609MiL region also appears to occur in waterin which dissolved oxygen levels are low.Most of the outfalls, other than the outfallsassociated with the heated coolant water forwhich search is being made under this Grant,have been detected by location of a darkstreak in other"ise light-toned water. Lighttones in the water appear to be caused pri­marily by oxygen-demanding biotic activity,based on correlation "'ith I"ational \YaterQuality data "'hich has been examined of theareas studied. Sediment load and \I"ater colorare, of course, also significant.

Heat, at the levels present in heated ccolantwater, or in the receiving discharge areas, willnot create photographic imagery. Muchhigher temperatures are required. Photo­graphic imagery can be quite successfully re­corded in the spectral region extending fromthe ultra-violet to the near infrared, the upperlimit being at approximately 1500MiL. Emis­si\'ity from the temperature region 30 degreesFahrenheit to 120 degrees Fahrenheit consistsof electromagnetic energy extending fromabout 9.3 to 10.8 microns in "'avelength,which is in the infrared region, well beyondthat which can be photographically recorded.

If one is to analyze thermal patterns inphotographic imagery, then, one must analyzesecondary imagery. This is imagery inducedby the heat, rather than actually picturing theheat itself.

As \I"as stated, a photographic system ispreferred, considering the current state of theart. Use of image-forming infrared sensors,"'hile offering several significant advantages,including discrete picturing of a heated watermass because of its emissi\'ity, offers manydisadvantages. The most nearly insurmount­able of these is Security Classification. Tnaddi tion, most of the systems curren tly inuse, with notable exceptions, exhibit con­siderable geometric distortion, and resolutionwell below that obtained in photography.

Studies to date support the hypothesis thatthermal boundaries can be pictured by re­cording the significant secondary character­istics.

Some of the significant physical effects ofheat on the aquatic environment are wellknown, but little previous effort appears tohave been directed toward analyzation ofthese effects, from the standpoint of possiblesecondary photographic image formation.

The factors noted to date which appear tooffer the greatest promise in photographicallypicturing desired meaningful imagery fromthe air include changes in the index of refrac-

660 PHOTOGRAMMETRIC ENGINEERING

tion, changes in density, changes in the satu­ration capacity for various chemical sub­stances in solution, changes in sediment loadtransporting capability, and changes in bioticactivity rates. In addition, alteration of capil­lary wa ve action below ou tfalls, and increasesin evaporation rates, under certain circum­stances, may aid in photographic image for­mation.

The index of refraction of water changesfrom 1.329 to 1.333 when the temperature islowered from 120 degrees Fahrenheit to 38degrees Fahrenheit. As the index of refrac­tion is reduced, light of certain wavelengthswill penetrate to greater depths.

The 70 foot depth obtai ned by the Coastand Geodetic Survey, for instance, was ob­tained in relatively clear water in the Carib­bean, off Puerto Rico, where the averagewater temperature was above 70 degreesFahrenheit.

Turbulent diffusion patterns have beennoted several times to date, which appear tobe caused by variations in the index of re­fraction of heated water in contact \\-ith coolerwater. This is quite well illustrated in Figure2. This photography was taken from 12,000feet, of the Potomac Electric Power Companyplant, at Buzzard's Point, on the AnacostiaRiver, in Washington, D_ C.

The density of water, of course, alsochanges \\-ith temperature. \Vater is at itsmaximum density at 4 degrees Centigrade,39.2 degrees Fahrenheit. Its density de­creases when its temperature is either raisedor lowered from that level.

FIG_ 2. Buzzard's Point Thermal Electric Plant,\Vashington, D. C. (Potomac Electric Power Com­pany) (Anacostia River).

Density changes appear to account for anumber of significant secondary effects, otherthan, of course, being the primary controllingfactor in changes in index of refraction, whichhas already been discussed.

Density changes appear to account for vari­ations in sediment transporting capacity.Studies curren tly in progress by the Geo­logical Survey indicate that changes in tem­perature have a noticeable effect both on theamount of sediment transported, and on thesize and type of particlesY

Changes in density may also cause theformation of a different form of surface wave,in certain instances. This may be the cause ofthe bright spectral pattern in the ConnecticutRiver, extending from the coolant water out­fall of the plant shown in Figure 3, and intoBaltimore Harbor, from the thermal electricplant shown in Figure 4.

FIG. 3. South Meadow Thermal Electric Plant, Hartford, Connecticut (Hartford Electric LightCompany) (Connecticut River).

ANALYSIS OF THERMAL POLLUTION FROM THE AIR

FIG. 4. Thermal Electric Plant, Baltimore Harbor, Baltimore, Maryland.

661

Answering the question "How do we applythese fundamentals to the detection ofthermal boundaries by aerial photographicinterpretation?" has been the major aim ofresearch to date.

Aerial photographic in terpretation is no"black art." It has been developed to a highstate, primarily for military intelligence pur­poses. Essentially, when correctly applied,modern interpretive techniques permit aninterpreter to study the equivalent of a pre­cisely scaled, minutely detailed three dimen­sional model of the terrain. The view studiedis somewhat analogous to the view a giantmight get of the Earth, as shO\\'n in Figure 5.This is sometimes called the "giant eye-base"concept. Vertical elevations are usually ex­aggerated, as the interpreter sees themthrough a stereoscope. This aids identifica-

,'"

FIG. 5. "The Giant Eye-Base" Concept.

tion, because low objects appear to leap outat the interpreter. This phenomenon is alsopotentially very important in current map­ping. Differential velocities appear as changesin elevation, when viewed through the stereo­scope. Extensive studies are currently inprogress in Canada to develop this aspect. 28

The basic "tools" of the photo intet"preterare, as shown in Figure 6, the stereoscope,usually of two pO\\'er magnification, some­times more powerful; the "tube magnifier," asmall transparent tube with a magnifying lensin one end, usually from 5 to 7 power, with ameasuring reticule in the other end, and a"thousandths of a foot" scale; and perhapsother simple measuring devices.

The photo interpreter looks simultaneouslyat two slightly diHerent views of the samearEta, through a stereoscope.

The human eye-brain combination fuses thetwo images, creating the impression of thepr~cisely scaled, mi nutely detailed, threedimensional model referred to previously.

These are only the basic tools and funda-

FIG. 6. The Basic Tools of Photointerpretation.

FIG. 7. Heated Collant Water Dispersion Diagram, Courtesy Maryland WaterPollution Control Commission.

FIG. 8. Vertical Aerial Photograph, HeatedCoolant Water Discharge Area, Dickerson (Mary­land) Thermal Electric Plant.

sion, of flows from the Potomac ElectricPower Company plant at Dickerson, Mary­land, into the Potomac River. The Dickersonplant, rated capacity 350 MvY, enters theriver, rises to the surface, and hugs the Mary­land shore for several miles. This condition isonly marginally visible in the sediment-ladenhigh water flows shown in Figure 8, takenearly in April, 1962, from an altitude of 2,000feet.

As the water progresses do\ynstream, theheated coolant water is deflected into thenarrow chan nel between Mason Island andthe Maryland shore. On leaving this channel,it encounters a small island. Turbulent flowsare exhibited near the downstream end of thisisland.

PHOTOGRAMMETRIC ENGINEERING

2-1/2° to SOWarmer

9200

662

men tals, of course. Much more precise-andexpensive-equipment (and techniques for itslise) is available for special applications.

Images are recognized by recognition oftheir size, shape, shadow, tone, pattern, tex­ture, and relationship \\·ith surrounding ob­jects, or location.

As is generally known, aerial photographiccoverage, at a scale of 1/20,000 is available ofmost of the United States, from the Depart­ment of Agriculture, the Geological Survey,and other sources within the Government.

In this study, preliminary aerial photo­graphic analyses were made of several thermalelectric plan ts, from a list of 30 provided bythe Federal Power Commission, both forevaluation of the existing photography, andin further analysis of the previously listedfundamen tals.

Light tonal anomalies, indicating that agreater amount of reflected light was reachingthe film, were noted in a swath, extendingfrom the outfalls of most of the plantsanalyzed. Most of the patterns, on initialentry into flo\\"ing streams, extend upstream ashort distance, against the current. They thenchange direction, and flow downstream, hug­ging the bank for a considerable distance,until ban k deflection elemen ts force themaway from shore. In only one instance noteddid the light tonal anomaly, still in visiblelaminar form, just disappear.

These conditions are also illustrated inFigure 7, a curren t diagram prepared by theMaryland Water Pollution Control Commis-

\~·~·r·(~~·7 ~rx

F1G.9. Raritan River Thermal Electric Plant .Sayrevillc .\Jcw Jcrscy (jerscy Central rower and Light Company) (Raritan Ri,·er).

:>z:>to<~(f).....(f)

o"'l

I...,~tIl:;::i~:>to<"doto<to<c:...,.....oZ>:;:;::io~...,~tIl

;:::;::i

0­0­W

664 PHOTOGRAMMETRIC ENGINEERING

FIG. 10. Thermal Electric Plant, Albany, New York, Hudson River.

A similar "shore hugging" phenomenon ap­pears to exist below the Rari tan Ri ver JerseyCentral Power and Light Company Plant onthe Raritan River, near Sayersville, NewJersey, shown in Figure 9.

This condition is perhaps even more evi­dent in flows below the Albany plant of theNiagara Mohawk Power Company, Albany,New York, on the Hudson River, shown inFigure 10. (Note: Plant identity uncon­firmed.)

Only slightly different conditions werenoted below the Martin's Creek PennsylvaniaPower and Light Company plant, nearStroudsburg, Pennsylvania, on the DelawareRiver, illustrated in Figure 11. Here, BigKaypush Rapids, and a series of groins con­structed along the western shore of the riverappear to force the heated coolant water outinto the main channel soon after exit from thedischarge canal. Subsurface water, however,appears to enter the river in considerablevolume just above Big Kaypush Rapids,forcing the surface riding heated coolantwater back along the western bank of theriver. The heated collant water continuesdownstream along the western bank, past therailroad bridge, until complete diffusionoccurs in Little Kaypush Rapids, furtherdownstream.

This analysis, performed entirely by aerialphotographic interpretation, agrees in detailwith findings by the Institute of Research,Lehigh University, except for the probableentry of subsurface water above Big Kaypush

Rapids. A probable current-induced spectralpattern extends from a trace on the east bankof the river which may mark the location of acrustal fracture trace.

Indications that the heated coolant waterhugs the shore were noted below the TitusMetropolitan Edison plant, shown in Figure12, and the Shawville Pennsylvania ElectricCompany plant, shown in Figure 13.

A slightly different condition was noted be­low the Sunbury Pennsylvania Power andLight Company plant near Shamokin Dam,Pennsylvania, as shown in Figure 14. Here, abright, probably wave-induced spectral pat­tern originates near the ou tfall, and extends aconsiderable distance downstream.

The course of flow into the ocean appears tofollow a different pattern.

The flow from the Salem plant, New Eng­land Power Company, at Salem, Massachu­setts into Salem Harbor, is shown in Figure15. Here, the flows appear to be initiallyvortical, when viewed stereoscopically. Theysubside to the right, around the end of thegroin seen in the illustration, then rise to thesurface, and extend far out to sea as a laminarflow. Essentially this same condition can beseen in flows from the Baltimore Harborthermal electric plant illustrated in Figure 4.Here, the flows appear to be differentiated bythe same type of spectral wave pattern previ­ously illustrated in some of the flows enteringstreams.

Several problems have been encounteredin analyses.

ANALYSIS OF THERMAL POLLUTION FROM THE AIR 665

FIG. 11. Martin's Creek Thermal Electric Plant,near Stroudsburg, Pennsylvania (PennsylvaniaPower and Light Company) (Delaware River).

First-insufficient base-line data, in mostinstances. It is axiomatic among photo inter­preters that the more knowledge one takes tothe photography, the more information onewill extract from them. Additional desirablebase-line data, it is felt, should include:

(1) Depth, width, and contour of streamchannels.

(2) Location and deflection angle of bankdeflection elements.

(3) Locations of obstructions of any sort inthe stream channel, which may induceturbulence.

(4) Seasonal \\'ater temperature profiles.(5) Types and amounts of flora and fauna

present in the water, and inducedturbidity values.

(6) Volu me and veloci ty of seasonal f10\\'s.(7) Location, volume and velocity of tribu­

tary streams.(8) Location, volume and velocity of

known entering subsurface f1oll's.(9) Composition of stream channel ma­

terial, to include:(a) porosi ty(b) chemical composition(c) particulate types and sizes(d) specific weight of particles

It should be pointed out that many of thesedesirable elements can probably be deter­mined in detailed analysis of large-scale, pref­erably multiband, aerial photography, in­cluding aerial color, and probably less expen­sively than by the type of detailed grounddata collection program required. "Fieldchecking," of course, must also be done, butthis is simplified if it follows preliminary in­terpretation.

In addition to the listed items, of course,National \Nater Quality Summary data, andsome of the additional data being collected bythe U. S. Geological Survey, and published inthe \Vater Supply Papers has proyed veryhelpful in analysis.

Following the preliminary photographicanalyses phases, a detailed sut"vey was madeof infrared equipment suitable for use fromthe air, which might prove valuable in analy­sis of the dispersion and diffusion of heatedcoolant water.

Infrared instru men ts sui table for moni tor­ing heated coolant water must be passive sys­tems I\"hich have a short time constant to re­spond to temperature changes in the II'atermass, and to the forward motion of the air­craft. The angle of view of the instrumentmust isolate critical water masses, If possible,the instru men t shou ld permi t di fferen tia tionof boundary layers of heated to cooler water.The temperature response of the instrumentmust include the spectral region extendingfrom 9.3 microns to 10,8 microns which corre­sponds to the critical temperature range,

666 PHOTOGRAMMETRIC ENGINEERING

FIG. 12. Titus Thermal Electric Plant, Reading, Pennsylvania (Schuylkill River)(Metropolitan Edison Company).

ANALYSIS OF THERMAL POLLUTION FROM THE AIR

FIG. 13. Shawville Thermal Electric Plant, Shawville, Pennsylvania (Susquehanna River)(Pennsylvania Electric Company).

667

668 PHOTOGRAMMETRIC ENGINEERING

FIG. 14. Sunbury Thermal Electric Plant, Shamokin Dam, Pennsylvania (Susquehanna River)(Pennsylvania Power and Light Company).

ANALYSIS OF THERMAL POLLCTlON FROM THE AIR 669

FIG. 15. Salem Thermal Electric Plant, Salem,Massachusetts (Salem Harbor) (~cw EnglandPower Company.)

Physical size of the instrument, and itspower requirements must correspond to theaircraft in which the instrument is to bemounted.

Remote temperature measure men ts can bemade with extreme accuracy from the air,using various types of infrared sensors. Onetype of aerial infrared sensor, for instance, re­portedly has an accuracy of .006 degreeCentigrade, from an altitude of several thou­sand feet.

Letters of inquiry were sent to twenty-fourmanufacturers of infrared instrumentationwhich might prove suitable as the triggeringelement of an Integrated Aerial Sensor Sys­tem. Analyses of the products of these com­panies led to the concl usion that two instru­ments were most suitable.

One of these is the Barnes J\lodel 14-310Portable Radiation Thermometer, manu­factured by Barnes Engineering, 30 Com­merce Road, Stamford, Connecticut.

The second instrument is the Block 14T,manufactured by Block Engineering, Cam­bridge, Massachusetts.

These two instruments are essentially non­competitive. Each has unique capabilities forsensing conditions in the aquatic environ­ment, which may well serve to greatly in­crease our knowledge.

Under the Integrated Sensor Concept, it ishoped that the infrared sensor can be used totrigger two 3S mm. cameras, in verticalmounts, when heated coolant water raises theaverage temperature of the receiving streaml°F.

In operation, aerial data collection underthis concept will follow this sequence:

1. On reaching a preselected point in aflight path approaching a thermal outfall, theaerial instrument operator (or pilot) turns onan infrared sensor for warm-up. Selection ofthis point depends on speed over the ground

approaching target, and required instrument"\VarIn-up" till1e.

2. On reaching a second preselected posi­tion, the aerial instrument operator (or pilot)turns on a single switch activating the infra­red sensor recorder and a K-24 "base" covercamera.

3. \;I,-hen the infrared sensor senses that theaverage temperature of the receiving streamis raised l°F. above a pre-set temperature (thetemperature of the river above the plant in­take) the sensor will activate the two 3S mm.cameras, each of which will probably beloaded with specially selected films and fittedwith selected filters or filter combinations.This will permit collection of "multiband"coverage. Pictures taken wi th each camerawill be spectrally different from those takenwith the other cameras. All pictures will betaken at almost exactly the same time, opticalaxes vertical and parallel. Time variation isunavoidable bet\\'een the K-24 and the 3Smm. cameras, if 60% overlap is maintained\\·i th the 3S m m. cameras, as is desired, be­cause of differences in format shape and size.Fortunately, this variation is considered tobe of only minor importance in subsequentanalysis.

4. The 3S mm. cameras will cease operatingwhen the infrared sensor detects that theaverage temperature of the stream hasdropped to less than l°F. above the pre-settemperature.

A map ill ustrating the type of coveragewhich it is hoped that this system will pro­duce is shown as Figure 16.

It is planned that the Integrated AerialSensor Concept be developed and employedin subsequent phases of the investigation, ifcontinuation of this program is authorized.

In conclusion, let me say that it is hopedthat the knowledge that has been gained inthe initial phase of this investigation is asvaluable in furthering our knowledge aboutthe aquatic environment, as the investigationhas been fascinating to conduct.

BIBLIOGRA PHY

1. Woodward, D. R., "Availability of vVater inthe U. S. with Special Reference to IndustrialNeeds by 1980." Washington, D. C, 1957.

2. "Water Requirements of Electric UtilitySteam-Electric Plants in 1959." FederalPower Commission.

3. "Steam-Electric Plant Construction Cost andAnnual Production Expenses"-thirteenthAnnual Supplement, 1960. Federal Power Com­mission.

4. Personal Communication, Dr. Richard H.Strain, Strong Memorial Hospital, Rochester,New York.

5. Proceedings-"Conference on PhysiologicalAspects of Water Quality." U. S. Public Health

670 PHOTOGRAMMETRIC ENGINEERING

Fig. 16. Simulated Coverage Diagram-Integrated Aerial Sensor Systems

Service, vVashington, D. c., September 8-9,1960.

6. Personal Communication-Mr. Paul McKee,Chairman, Maryland Water Pollution ControlCommission, Annapolis, Maryland.

7. "The Thermal Pollution Problem," Dr.Richard D. Hoak, Joumal of the Water Pollu­tion Control Federation. December, 1961.

8. Personal Communication-Mr. R. G. GodfreyU. S. Geological Survey, Director of Project

Number 3254 "Dispersion 111 NaturaStreams."

9. "Some Important Biological Effects of Pollu­tion Often Disregarded in Stream Surveys."Purdue University Engineering Bulletin"Proceedings of the 8th Industrial WastesConference-May 4, 5, 6, 1953." Dr. Clar­ence M. Tarzwell.

10. Personal Communication-Mr. Harold Elser.Maryland Department of Game and Inland

ANALYSIS OF THERMAL POLLUTION FROM THE AIR 671

Fisheries. Annapolis, Maryland.11. "Research Project on Effects of Condenser

Discharge Water on Aquatic Life." ProgressReport 1956 to 1958. The Institute of Re­search, Lehigh University. October 1, 1959.

12. "Effect of Addition of Heat from a PowerPlant on the Thermal Structure and Evapora­tion of Lake Colorado City, Texas." U. S.Geological Survey Professional Paper 272-B.

13. "The Use of Reservoirs and Lakes for theDissipation of Heat." U. S. Geological SurveyCircular 282.

14. "Water Loss Investigations: Lake MeadStudies." U. S. Geological Survey ProfessionalPaper 298.

15. "'Vater Loss Investigation: Lake HefnerStudies." Technical Report. U. S. GeologicalSurvey Professional Paper 269.

16. "Pond Cooling by Surface Evaporation."D. O. Lima, Power, Vol. 80 (1936), 10 . 3,pp. 142-144.

17. "How to Predict Lake Cooling Action." R. F.Thorne, Power, Vol. 95 (1961), No.9, pp.86­89.

18. "Cooling Ponds May Answer Your \VaterCooling Problem." J. W. Langhear, ChemicalEngineering, August 1953, pp. 194-J98.

19. "The Use of Surface and Ground Water forCooling Purposes for Steam Electric Generat­ing Stations in Texas." M. G. Salzmann ASCEProceedings, Vol. 82, August 1956, Paper No.1044.

20. "Report on the Behavior of Power StationCooling Ponds." J". Lamb, Assistant Engineer,Projects Division, Power Development Branch,The Electricity Commission of New SouthWales, Australia.

21. "Forecasting Heat Loss in Ponds andStreams." C. J. Velz and J. J. GannonJournal of the Water PoUution Control Federa­ti"n, April 1960, p. 392.

22. "Cooling Pond Design in the South West."T. J. Cotter and A. W. Lotz, Proceedings of theASCE, Journal of Powel' Division, PO 2, July1961.

23. "Condensing Water-How Does It Affect theRiver?" Melvin D. Engle, Mechanical En­gineering, Vol. 82, No.1, January 1961.

24. " Heated Discharges-Their Effect on Streams."A Report by the Advisory Committee for theControl of Stream Temperatures to thePennsylvania Sanitary Water Board, J an­uary 1962. Division of Sanitary Engineering,Bureau of Environmen tal Health, Penn­sylvania Department of Health, Harrisburg,Pennsylvania.

25. "The Procurement of Aerial Photography ofndenvater Objects. An Analysis of the

Problem by Russian Scientists." AppendixC. Chapter 2, MANUAL OF PHOTOGRAPHICINTERPRETATION, American Society of Photo­grammetry, 1960. (Editor in Chief, Dr.Robert I. Colwell, Department of Forestry,University of California.)

26. Personal Communication-Mr. William D.Harris, Chief of Photogrammetric Research,

. S. Coast and Geodetic Survey, Washington,D. C.

27. PersonaICommunication-Mr. D. M. Culbert­son, U. S.. Geological Survey, Lincoln,Nebraska. Director of Project Number 2701"Sediment Transport Investigations."

28. Personal Communication-Professor H. L.Cameron, Nova Scotia Research Fou ndation,Halifax, Nova Scotia (Canada).

ACKNOWLEDGMENTS

A great number of persons, both profes­sional photointerpreters and professional r:er­sonnel in other arts and sciences have willinglyassisted the Principal Investigator in this R~­

search. So many, in fact, that it is difficult toname them. Particular grati tude is expressedto:

Mr. Harry Faber, Chief, Research and TrainingGrants Branch, Division of Water Supply andPollution Control. US PHS.

Mr. James Coulter, Chief Water Projects Sec­tion, Technical Services Branch, Division ofWater Supply and Pollution Control, USPHS.

Dr, Richard A. Geyer, Chief Oceanographer,Texas Instruments, Inc., Dallas, Texas.

Dr. D. W. Pritchard, Chesapeake Bay In­stitute, Johns Hopkins University.

Dr. William H. Strain, Strong Memorial Hospital,Rochester, j ew York.

Mr. S. V. Griffith, Bureau of the Budget, Wash­ington, D. C.

Dr. Ralph Fuhrman, Water Pollution ControlFederation, Washington, D. C.

Mr. Paul W. McKee, Director, Maryland "VaterPollution Commission.

Mr. Sylvin Belkov, District Engineer, Mary­land Water Pollution Control Commission.

Dr. Frank Schwartz, Chesapeake BiologicalLaboratory, Soloman's, Maryland.

Mr. Richard G. Godfrey, U. S. GeologicalSurvey.

Mr. Harold Elser, Maryland Department ofGame and Inland Fisheries.

Mr. William D. Harris, Chief, PhotogrammetricResearch, U. S. Coast and Geodetic Survey.

M r. D. M. Culbertson, U. S. Geological Survey.Professor Charles E. Olson, J r., Chairman, Com­

mittee on Aerial Photography, University ofIllinois.

Professor H. L. Cameron, Nova Scotia ResearchFoundation, Halifax, Nova Scotia, Canada.

(Mrs.) Malin Sundberg-Falkenmark, Royal In­stitute of Meteorology and Hydrology, Stock­holm, Sweden.

Dr. Robert N. Colwell, University of California.Dr. Myron Block, Block Engineering, Cam­

bridge, Massachusetts.Mr. Ansel Gere, Engineering Service Associates,

Washington, D. C.Mr. Wendell M. Smith, Barnes Engineering,

Stamford, Connecticu t.Mr. O. L. Hooper, Chief Hydraulic Engineer,

Stone and Webster Engineering Corporation,Boston, Massachusetts.

Mr. Page Truesdell, U. S. Naval PhotographicInterpretation Center, Suitland, Maryland.

Mr. Charles G. Coleman, U. S. Naval Photo­graphic Interpretation Center.

Mr. William Fischer, U. S. Geological Survey.Dr. Jack Van Lopik, Texas Instruments Inc.,

Dallas, Texas.Mr. Edward Tinsley, Chief, Geosciences De­

partment, Science Services Division, TexasInstruments, Inc., Dallas, Texas.

Mr. Julian F. Arntz, Jr., U. S. Navy.Dr. Robert H. L. Howe, "Vest Lafayette,

Indiana.Dr. Don E. Bloodgood, Chairman of this Con­

ference, and, of course,My fellow em ployees at General Research and

Development, Inc.