could a residential wood ash recycling …...as wood ash can be used as a restorative additive to...
TRANSCRIPT
COULD A RESIDENTIAL WOOD ASH RECYCLING PROGRAMME HELP SOLVE THE CALCIUM DECLINE PROBLEM: INSIGHTS FROM A MUSKOKA WOOD BURNER’S QUESTIONNAIRE
Shakira Azan, PhD
ii
We gratefully acknowledge the financial support for this research provided by
Copyright © 2017 Friends of the Muskoka Watershed
This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.
Report # 2017-10-HATSEO-1
Please direct all questions and comments to: [email protected]
i
ACKNOWLEDGEMENTS
Wethankthe53Muskokaresidentswhocompletedthequestionnaireontheirwoodash
generation and use, Joel Yan for pointing us to the biennial survey on primary heating
systems in Canadian households conducted by Statistics Canada, and Norman Yan for
commentsondraftsofthisreport.
ii
TABLEOFCONTENTS
ACKNOWLEDGEMENTS...........................................................................................................................................................i
TABLEOFCONTENTS..............................................................................................................................................................ii
LISTOFFIGURES......................................................................................................................................................................iii
LISTOFAPPENDICES..............................................................................................................................................................iii
1.0 INTRODUCTION...........................................................................................................................................................1
2.0 SURVEYRATIONALE.................................................................................................................................................2
3.0 METHODOLOGY...........................................................................................................................................................3
4.0 FINDINGSOFTHEWOODASHSURVEY............................................................................................................3
4.1 Woodasaheatingsource....................................................................................................................................3
4.2 Mainsourceofwood..............................................................................................................................................3
4.3 Partsoftreeusedtoproducewoodash..........................................................................................................4
4.4 Treespeciesusedtoproducewoodash..........................................................................................................5
4.5 Currentusesofwoodash.....................................................................................................................................6
4.6 Seasonalashproduction.......................................................................................................................................7
4.7 Participationinresidentialwoodashprogramme....................................................................................7
4.8 Bucketsofashproducedduringheatingseason.........................................................................................9
4.9 Numberoffacecordsburntduringheatingseason...................................................................................9
5.0 GAPSANDRECOMMENDATIONS.....................................................................................................................11
6.0 ISTHEREENOUGHWOODASHTOHELPSOLVETHECADECLINEPROBLEM?.........................11
7.0 REFERENCES.............................................................................................................................................................15
APPENDIX..................................................................................................................................................................................17
iii
LISTOFFIGURES
Figure1:Piechartshowingpercentageofwoodorwoodfueltypesusedbyrespondents.....................4
Figure2:Piechartshowingpercentageofmainpartsoftreesusedbyrespondentsinwoodash
production....................................................................................................................................................................................5
Figure3:Piechartshowingpercentageoftreespeciesusedbyrespondentsinwoodashproduction
............................................................................................................................................................................................................6
Figure4:Piechartshowingpercentageuseofwoodashproducedbyrespondents..................................7
Figure5:Piechartshowingwillingnessofrespondentstoparticipateinaresidentialwoodash
recyclingprogramme...............................................................................................................................................................8
Figure6:Piechartshowinghowmanybucketsofashareproducedbyrespondentsduringthe
heatingseason..........................................................................................................................................................................10
Figure7:Piechartshowingthedistributionoftheamountofwood(infacecords)burntperyear10
LISTOFAPPENDICES
Appendix1:SurveyofwoodashusersinMuskoka................................................................................................18
1
1.0 INTRODUCTION
Overthepastseveraldecades,calcium(Ca)concentrationshavebeendeclininginMuskoka
lakes and forests. In 2014,TheMuskokaWatershed Council’s Report Cardhighlighted Ca
declineasanewenvironmentalstressoraffectinglakehealthinthearea.Thedamagecaused
bydecliningCaconcentrationisallaroundus.Inforests,lossofCahasresultedinslowed
growth,seedproduction,seedlingregenerationanddiebackofsugarmaplethatcanimpact
maplesyrupproduction.Inlakes,crayfishthathavehighCa-demandsaredisappearing.Last,
in offshore waters, a jelly-clad water flea, Holopedium, is replacing its more Ca-rich
competitors,andcreatingthepotentialtoclogwaterfiltersforresidentsdrawingtheirwater
fromlakes.
One possible solution to combatting Ca decline is active local engagement, ifMuskokans
become“gardenersoftheforest”.Asgardeners,wecanusewoodash-theresidueremaining
afterthecombustionofwood–toreturnCatoforestsoilswhereitoriginated.Woodash
containsmanyelements–bothmajorandminor–thatarerequiredfortreegrowth(e.g.,
calcium,potassium,nitrogen,phosphorus).Oftheelementspresent,Caisthemostabundant
withcalciumcompoundsformingbetween15%1and50%2oftotalashweight,followedby
potassium(K),magnesium(Mg),aluminium(Al),iron(Fe)andphosphorus(P).3Duetoits
highCacontent–mainlyascalciumcarbonate(CaCO3)-woodashisrelativelyalkalineand
canbeusedasagardenfertilizer.Inaddition,woodashcanbeusedforpestcontrol,tomake
soap, tomelt iceandsnow,absorbodours, removeoil stainsondrivewayorgarage,and
polishsilver.
2
Theuseofwoodashasaforestorsoilamendmentisnotunusual.Innorth-eastUnitedStates
ofAmerica,80%ofwoodashproducedisusedinlandapplication1.InEurope(e.g.,Sweden,
Finland,andUnitedKingdom),woodashisoftenaddedtoforestsoilstoenhancebiomass
production. In Canada,wood ash ismainly used for liming and/or fertilizing in Alberta,
British Columbia, NewBrunswick, Nova Scotia, andQuebec. In Ontario,wood ash is not
regularlyusedasasoilamendmentonagriculturalorforestsoils,andtherearecurrentlyno
guidelinesforsuchuses.4
2.0 SURVEYRATIONALE
Aswoodash canbeusedas a restorativeadditive to gardenand forest soils, andas ash
recycling programmes have worked in other countries (e.g., Sweden and Finland), the
FriendsoftheMuskokaWatershed(FMW)decidedtogainanunderstandingofwoodash
productionanduseintheMuskoka.Ourprimaryobjectivesweretodetermine:1)themain
sourcesofwoodusedduringtheheatingseason;2)ifandhowMuskokanswerewillingto
participateinaresidentialwoodashrecyclingprogramme;and3)howmanybucketsofash
areproducedduringtheheatingseason.Thissurveyfallsundertheumbrellaofthe“Hauling
Ash to Solve Ecological Osteoporosis” or “HATSEO” project that is funded by anOntario
TrilliumFoundationSeedGrantandaimstoturnawasteproduct–woodash–intoauseful
fertilizerthatcombatsCadecline.
3
3.0 METHODOLOGY
TheSurveyofWoodAshUsersinMuskokawaspreparedanddistributedtoFMWmembers
andpostedontheFMWwebsite1onMarch7,2017.Electroniccopiesofthesurveywerealso
senttoLakeofBaysAssociation,KawagamaLakeCottagersAssociation,andthelocalbranch
oftheOntarioMapleSyrupAssociation(SweetwaterMapleSyrupSuppliesandSugarbush).
The survey was also promoted via individual Twitter and/or Facebook pages, and
distributionlists.AcopyofthequestionnaireisattachedasAppendix1.
4.0 FINDINGSOFTHEWOODASHSURVEY
4.1 Woodasaheatingsource
Intotal,53completedquestionnaireswerereceivedandallrespondentsusedwoodorwood
productsasaheatingsource.Therewasnoindicationthatresidentsusedthewoodforother
purposessuchasmaplesyrupproduction,bonfires,eliminationofgardenoryardwaste,or
woodfiredcooking.
4.2 Mainsourceofwood
ThemainsourceofwoodashproducedinMuskokawasfromhardwood,whichwasusedby
57%oftherespondents.Twenty-sixpercentoftherespondentsused ‘mixed’wood, i.e.,a
mixture of hardwood tree pieces purchased froma supplier. Softwood andwoodpellets
werenotaswidelyusedashardwoodtreespecies,andaccountedfor14%and3%ofthe
respondents,respectively(Figure1).Biocharwasnotusedbyanyoftherespondents.
1http://friendsofthemuskokawatershed.org/hatseo-survey/
4
Figure1:Piechartshowingpercentageofwoodorwoodfueltypesusedbyrespondents
4.3 Partsoftreeusedtoproducewoodash
Themajorityoftherespondentsusedthestemortrunkoftreesasaheatingsource(44%).
Otherrespondentsusedthebark(30%)orbranches(26%)(Figure2).Treerootsorfoliage
werenotusedbyanyoftherespondentstoproducewoodash.
26%
57%
14% 3%
Mixed
Hardwood
Softwood
Woodpellet
5
Figure2:Piechartshowingpercentageofmainpartsoftreesusedbyrespondentsinwoodash
production
4.4 Treespeciesusedtoproducewoodash
Manytreespecieswereusedasfuel,andthustoproduceashinMuskoka.Themajorityof
therespondentsusedthehardwoodtreespeciesmaple(29%)toproducewoodash.Other
hardwoodspeciesusedwerebeech(19%),oak(17%),birch(14%),ash(4%),andcherry
(2%). Aspen, basswood, elm, moose-maple, and poplar, each accounted for 1% of the
responses(Figure3).
Softwood treespecieswerealsoused toproducewoodash,but in smalleramounts.The
softwoodspecieshemlockandpine,bothaccountedfor2%oftherespondents.Spruce,cedar
andbalsamwerealsoused,buteachaccountedfor1%oftheresponses.Fourpercentofthe
respondentshadnoknowledgeofthetreespeciestheyused(Figure3).
30%
26%
44% Bark
Branch
Stem/Trunk
6
Figure3:Piechartshowingpercentageoftreespeciesusedbyrespondentsinwoodashproduction
4.5 Currentusesofwoodash
ThemajorityofwoodashproducedinMuskokaisusedasfertilizeringardens(39%)(Figure
4).Otherprimaryuses includedcompost(24%),andmelting iceandsnowondriveways
(19%).Fewrespondentsusedwoodashintheirhomes(3%)(e.g.,cleaningglassonthewood
stove) and for pest control (3%). In contrast, some respondents did not use wood ash
produced,butdisposedof it in themunicipal landfill (4%),or ina forestedareaon their
property(6%)(Figure4).
19%
29%
17%
14%
4%
2% 2%
2% 1%
1% 1% 1% 1% 1% 1% 1% 4%
Beech
Maple
Oak
Birch
Ash
Cherry
Hemlock
Pine
Elm
Poplar
Cedar
Aspen
Spruce
7
Figure4:Piechartshowingpercentageuseofwoodashproducedbyrespondents
4.6 Seasonalashproduction
Ofthe53respondentsthatsubmittedacompletedquestionnaire,35(66%)usedwoodasa
heating source only in thewinter. The remaining 18 respondents usedwood during the
winterinconjunctionwithfallandspring(50%),fall,springandsummer(44%)orfallalone
(6%).
4.7 Participationinresidentialwoodashprogramme
Ofthe53respondentsthatsubmittedacompletedquestionnaire,only3personswerenot
interested in participating in a wood ash recycling programme. Most of the willing
participantspreferredtotransporttheirwoodashtothemunicipal landfill(29%)ortoa
centralizedlocationclosertohome(23%)(Figure5).Eighteenpercentoftherespondents
24%
39%
19%
3%
3% 4%
6% 2%
Compost
Fertilizer
Driveway
Pest
Inthehome
Disposal- landfill
Disposal- woods
Other
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werewillingtoseparatewoodashfromorganicwasteforcurbsidepickup.However,this
activity is likelynot feasibleas theDistrictofMuskokaMunicipalityhas indicated that it
wouldbeanexpensiveundertaking.
Muskokanswere alsowilling to participate in the distribution ofwood ash to the forest
(15%),tohelppromoteandparticipateinan“ashdrive”gearedtowardscollectingwoodash
inandaroundMuskoka(8%),ortoserveonawoodashrecyclingprogramme’sadvisory
committee(4%).Threepercentoftherespondentspreferredtocontinuedisposingofwood
ashinaforestedareaontheirownproperties(Figure5).
Figure5:Piechartshowingwillingnessofrespondentstoparticipateinaresidentialwoodash
recyclingprogramme
29%
23% 18%
15%
8% 4% 3%
Landfill
Closetohome
Curb
Ashdistributn
Ashdrive
Advisory
Other
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4.8 Bucketsofashproducedduringheatingseason
Duringtheheatingseason,30%oftherespondentsproducedeithermorethan20buckets
ofwoodashor5to10buckets,whereas28%producedeither10to20buckets(Figure6).
Incontrast,fewrespondentsproducedsmallernumbersofbucketsofash.Forexample,3to
5buckets(10%)and1to2buckets(2%)(Figure6).
IfweassumethataMuskokanusesanashbucketthathasavolumeof17.7L(3.9gal)5,the
mostcommonsize,thenthe53respondentswouldproduceabout12151L(~3210gal)of
woodash.Giventhatthedensityofwoodflyashis548kgpercubicmetre6,thenthese53
Muskokanswould produce, on average, 125.6 kg ofwood ash per individual during the
heatingseason.
4.9 Numberoffacecordsburntduringheatingseason
Theamountofwood(infacecords)burntduringtheheatingseasonvaries.Themajorityof
therespondentsburntmorethan5facecords(38%)duringtheheatingseason(Figure7).
Otherrespondentsburntbetween1and2facecords(22%),2to3facecords(16%),4to5
facecords(12%)or3to4facecords(10%)(Figure7).Fewrespondentsburntlessthan1
facecord(2%).
Overall,the53respondentsburnt176.5facecordsduringtheheatingseason.Asafacecord
is1/4afullcord(weighsapproximately2tons)7,thenonaverage,about1500kgofwoodis
burntperindividualduringtheheatingseason.
10
Figure6:Piechartshowinghowmanybucketsofashareproducedbyrespondentsduringthe
heatingseason
Figure7:Piechartshowingthedistributionoftheamountofwood(infacecords)burntperyear
2% 10%
30%
28%
30%
1to2
3to5
5to10
10to20
>20
2%
22%
16%
10% 12%
38% 0to1
1to2
2to3
3to4
4to5
>5
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5.0 GAPSANDRECOMMENDATIONS
ThepurposeoftheSurveyofWoodAshUserswastogatherinformationonwooduseand
wood ash production inMuskoka. The surveywas distributed tomembers of the FMW,
cottageassociations,andmaplesyrupproducerswhowerethoughttousewoodasaheating
source.WithinMuskoka,thereare60,599permanentand85,163seasonalresidents8.If3%
ofthepopulationheatswithwood9,thenthenumberofsurveyresponsesreceived(<1%of
the number that heatwithwood)may not be a representative sample. A larger sample
shouldbesought,asitislikelymoreinformationwillbeneededtodeterminethefeasibility
ofestablishingaresidentialwoodashrecyclingprogrammeinMuskokathathasthepurpose
ofhelpingtosolvetheenvironmentalCadeclineproblem.Inaddition,moreinformationon
woodashproductionwouldassist indetermining if enoughwoodashcouldbecollected
fromresidencesand/orcommercialbusinessesfordistributiontothenorth-easternportion
ofthe2EBWatershed,i.e.,theHollowRiverQuaternaryWatershed,where>50%ofthelakes
haveCalevelsbelow1.5mgCa/L,alevelatwhichCa-richbiotasufferpopulationdamage.
6.0 ISTHEREENOUGHWOODASHTOHELPSOLVETHECADECLINEPROBLEM?
Scenario1
Thereare60,599permanentresidentsinMuskoka,ofwhich3%heatwood.Assumingour
surveyprovidedaccurateestimates,themajorityofMuskokansthatheatwithwoodproduce
about20bucketsofashperheatingseason,whichequatestoapproximately36,359buckets
ofwoodashinthewatershed.Assuminganashpailholds17.7L,permanentresidentswould
12
generateabout643,561L(644m3)ofwoodash.Asthedensityofwoodashaveragesabout
548kgper cubicmetre6 (it varieswithwood species), approximately352,672kg (~353
tonnes)ofashwouldbeproduced.Asoursurveyindicated2/3oftherespondentswouldbe
willingtotransportwoodashtothedumporlandfill,oranearbytransferstation,theycould
provideabout235,000kg(235tonnes)ofashperyeartoawoodashrecyclingprogram.
ThisamountofashwouldbeenoughtotreattheCadeclineprobleminroughly58hectares
ofMuskokaforestatanapplicationrateof4tonnesperhectareperyear.Storageofthismuch
woodashforannualdistributionrequiresa500m3building,andthesearereadilyavailable
forsaltstorage.
Scenario2
Thereareanestimated145,762residents(permanentandseasonalcombined)inMuskoka,
especiallyduringthesummer.If3%heatwithwoodandgenerate20bucketsofash,87,457
bucketsofwoodashwouldbeproduced.A17.7Lpailwouldgenerateabout1,547,992L
(~1548m3)ofash.If2/3oftheresidentsarewillingtotransportwoodashtothelandfill,
thenFMWwouldhave~566,000kg(566tonnes)ofashavailableperyear.Withthisamount
ofash,approximately140hectaresofMuskokaforestcouldbetreatedatanapplicationrate
of4tonnesperhectareperyear.
Conclusion
Witheitherscenario,theamountofwoodashgeneratedfortheapplicationof1tonneper
hectare,iscertainlyadequateforalargescalepilotprojectorfeasibilitystudyonwoodash
13
collectionandapplication;however,notenoughtosolvetheproblemacrossMuskoka,given
thewidespreadnatureofCadecline.
TosolvetheCaproblem,i.e.,eliminateCalimitationoftreegrowth,andprovideexcessCa
that couldenter lakewaters, aminimumofabout4000kg (4 tonnes)perhectareofash
wouldlikelyneedtobeapplied(CarolynReid,TrentUniversity,pers.comm.).TheHollow
RiverWatershedisapproximately40,000hectares.If53residentsproduceabout12,151L
ofashthatwouldweighroughly6659kg(~7tonnes),thenFMWwouldrequirewoodash
fromabout41,000peopletotreattheentirewatershed.Therearecertainlyenoughpeople
intheprovincethatheatwithwoodtoprovidethismuchash,butnotinMuskokaalone.
Asof2016,Ontario’spopulationwas13.9M.Ofthese,1%usewoodorwoodpelletsastheir
primaryheatingsystem.Assumingeachofthesepersonsgenerate20bucketsofash,then
about2.8Mbucketsofashwouldbeproduced.Assuming17.7Lpails,Ontariowoodburners
wouldgenerateabout49.5ML(~50,000m3)ofash.Assuming2/3ofresidentsinOntario
arewillingtotransportwoodashtothelandfill,thenFMWwouldhave~18.1Mkg(about
18000tonnes)ofashavailableperyear.Therefore,FMWcouldtreatapproximately4,500
hectaresperyearwithwoodashtohelpalleviatetheCadeclineproblem.AstheHollowRiver
Watershed is40,000hectares, aprovincewidewoodashrecyclingprogrammemaywell
solve the current Ca decline problem in 9 to 10 years with available ash supplies. A
permanentwoodashrecyclingprogrammecould thencontinue tosupport forestgrowth
andlakehealthinthefuture.Basedontheseestimates,a largerscalewoodashrecycling
programmeisjustified,assumingtherearenootherproblemsthattheuseofwoodashmight
14
cause.Wewilladdressthesepotentialproblems(metallevelsandaquatictoxicity)inour
nexttechnicalreport
15
7.0 REFERENCES
1. Risse,L.M.&J.W.Gaskin.(2002).Bestmanagementpracticesforwoodashasagriculturalsoil
amendment. Bulletin 1141. The University of Georgia Cooperative Extension. Available at
http://extension.uga.edu/publications/detail.html?number=B1142 (Accessed September 28,
2017)
2. Perry,E. (n.d.).Woodashesasagarden fertilizer.UniversityofCalifornia,Cooperative
Extension,DivisionofAgriculturalSciences-VegetableResearchandInformationCenter.
Leaflet 21305. Available at http://vric.ucdavis.edu/pdf/fertilization_Woodashes.pdf
(AccessedJuly7,2017)
3. Reid, C. & S. A. Watmough. (2014). Evaluating the effects of liming and wood-ash
treatmenton forestecosystems throughsystematicmeta-analysis.Canadian Journalof
ForestryResearch44:867-885.
4. Hannam,K.D.,C.Deschamps,M.Kwiaton,L.Venier,&P.W.Hazlett.(2016).Regulations
andguidelinesfortheuseofwoodashasasoilamendmentinCanadianforests.Natural
ResourcesCanada,CanadianForestryService,Ontario,Canada.
5. CanadianTire.(n.d.).BlackCoalHod.Availableathttp://www.canadiantire.ca/en/
pdp/black-coal-hod-0642749p.html#srp(AccessedOctober4,2017).
16
6. Naik,T.R.,R.N.Kraus,&R.Kumar.(2001).Woodash:anewsourceofpozzolanicmaterial.
ReportNo.CBU-2001-10.Availableathttps://www4.uwm.edu/cbu/Papers
/2001%20CBU%20Reports/CBU%202001-10.pdf(AccessedOctober4,2017).
7.NorthernHardwood.(2007).Wood-informed.
Availableathttp://www.northernhardwood.ca.informed-firewood-ontario.htm
(AccessedOctober9,2017).
8.TheDistrictMunicipalityofMuskoka.(2015-2016).Population:permanentandseasonal
populations.Availableathttps://www.muskoka.on.ca/
en/work-and-invest/Population.aspx(AccessedOctober5,2017).
9. Statistics Canada. (n.d.). Table 153-0145: Households and the environment survey,
primaryheatingsystem,Canada,provincesandcensusmetropolitanareas(CMA),every
2years(percent),CANSIM(database).Availableathttp://www5.statcan.gc.ca/cansim/
a26?lang=eng&retrLang=eng&id=1530145&pattern=&csid=(AccessedOctober9,
2017).
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APPENDIX
18
Appendix1:SurveyofwoodashusersinMuskoka
SURVEYOFWOODASHUSERSINMUSKOKA
Name:________________________________________________________________Address/Tele/Email:_______________________________________________________________________________________________________________________________________________________________________________________Pleaseindicatewithatickorticks(Ö)youranswer(s).1. Doyouusewoodorwoodproductsasaheatingsource?
� Yes � No
2. Ifyouarenotusingwood/woodproductsforheat,howareyouusingit?� Forbonfires� Foreliminationofyardorgardenwaste� Forwoodfiredcooking(e.g.,anoutdoorpizzaoven)� Topreparemaplesyrup� Other(pleasespecify)________________________________________________________________________
3. Whatis/arethemainsource(s)ofwoodyouuse?
� Biochar� Mixedwood� Hardwood� Softwood� Woodpellets� Other(pleasespecify)___________________________________________________________________________
4. Whatpartsofthetreesdoyouusuallyuse(tickallthatapply)?� Bark� Branches� Foliage� Roots� Stem/trunk� Other(pleasespecify)_______________________________________________________________________
5. Whattreespeciesprovideyourwood?� Beech� Maple� Oak� Other(pleasespecify)________________________________________________________________________
19
6. Howdoyouusetheashyouproduce?� Compost� Fertilizeronyourproperty� Pestcontrol(e.g.,deterslugsandsnails)� Melticeandsnowondriveway� Makingsoap� Aroundthehouse(e.g.,absorbodours,polishsilver)� Other(pleasespecify)________________________________________________________________________
7. Doyouproducewoodashonlyinthewinter?� Yes � No
8. Ifyoudonotproducewoodashonlyinthewinter,whenelsedoyoudoso?� Autumn� Spring� Summer
9. AreyouwillingtoparticipateinawoodashrecyclingprogrammeintheMuskoka?� Yes � No
10. Ifyes,howareyouwillingtoparticipate?� Transportwoodashtolandfill,i.e.thedump� Transportwoodashtoacentralizedlocationclosertohome� Separateashfromorganicwasteforcurbsidepickup� Participateinateamthatdistributesashintheforest� Helppromoteandparticipateinan“ashdrive”� Serveonawoodashrecyclingprogram’sadvisorycommittee� Other(pleasespecify)________________________________________________________________________
11. Howmanybucketsofashdoyouproduceduringtheheatingseason?� 1-2� 3-5� 5-10� >10
20
� Other(pleasespecify)_______________________________________________________________________
12. Howmanyfacecords(4’Hx8’Lx16”D)ofwooddoyouburnduringtheheating?� 1-2� 2-3� 3-4� >5� Other(pleasespecify)_______________________________________________________________________
THANKYOUFORYOURPARTICIPATION