updated project description commercial oyster shell mining ... · oyster shell was harvested as...

LindTugandBarge,Inc.-UpdatedProjectDescription-OysterShellMininginSouthSanFranciscoBay

UpdatedProjectDescriptionCommercialOysterShellMiningbyLindTugandBarge,Inc.within

SouthSanFranciscoBay

August2020

1. PROJECTDESCRIPTION

1.1. BackgroundandHistoryLindTugandBarge,Inc.(LTB),formerlyMorrisTugandBarge,commerciallymineshistoricoystershelldepositsfromsubtidalareaslocatedwithinSouthSanFranciscoBay.Oystershellwasharvestedasearlyas1891foruseingardenwalksandotherpurposesandhasbeencommerciallyminedfromtheSouthBaysince1924(Hart1978).LTBhasbeenminingoystershellfromtheSouthBayforabout40years,butthesamebasiccompanyhasbeeninbusinessforover90years,harvestingoystershellsandprocessingthematthePetalumaplant.Fromthemid-1920'sthroughthe1980'sthelargestquantitiesofoystershellwereminedfromthebayforuseasarawmaterialinthemanufactureofcement(bycompaniesotherthanLTB,whichneverminedshellforcementuse;theseoperationsnolongerexist).Morerecentlytheoystershellhasbeenprimarilyprocessedandusedasahigh-grademineralandnutrientsupplementinpoultrydiets,asasoilamendment,forpharmaceuticals,andasanamendmenttoneutralizelivestockwaste.Thelocationofminingandminingmethodshasremainedvirtuallyunchangedoverthisperiod.Thecurrentminingmethodsandlocationsareproposedtoremainthesameinthefuture.OystershellminingoccursonlywithintheCaliforniaStateLandsCommission(CSLC)designatedleaseareaPRC5534.1,locatedinSouthSanFranciscoBayadjacenttotheSanMateoBridge(Figure1-1).Theleaseareaisapproximately1,560acresinsize(Figure1-2)withinashallow(waterdepthsaretypically15feetorless),openwatersubtidalareaofthebay.ThehistoricoystershelldepositoriginatedintheLateQuaternary(Holocene)period,approximately2,300to2,500yearsago,whenthenativeoyster(Ostrealurida)populationflourishedwithinthebay(thenativeoysterwassmall,notmuchlargerthanahumanfingernail).Morerecently,pollutionvirtuallyeliminatedoystersfromthebay(Skinner1962).Thehistoricoystershelldepositsoccurprimarilyintheupper30feetofyoungbaymuddepositsandaretypicallyoverlaidandintermixedwithdepositsoffinesediment.Althoughthereisinterestinreestablishingoysterpopulationswithinthebay,primarilyinCentralBay,thefinegrainedmudsubstrateandhighambientturbidityandsuspendedsedimentconcentrationsthatoccurintheSouthBaycontributetounsuitablehabitatconditionsforoysterswithintheareaoftherelichistoricoystershelldeposits,andthereforemakereestablishingoystersintheareawhereminingoccursundercurrentenvironmentalconditionsunlikely.

LindTugandBarge,Inc.-UpdatedProjectDescription-OysterShellMininginSouthSanFranciscoBayHarvestofrelicoystershellfromtheSouthBayleaseareaallowsLTB,aspartofactivitiesthathavebeenongoingfordecades,tocontinuetoprovideoystershellproductsforcommercialsaleasagriculturalsoilamendment,calciumfoodsupplementforpoultryandlivestockandothercommercialbeneficialuses.

1.2. Purpose,ProposedActionandOysterShellMiningLocationsThepurposeofoystershellminingistoharvestrelichistoricoystershelldepositsfromSouthSanFranciscoBayforprocessingandcommercialsaleasasoilamendmenttoneutralizeacidicsoilsandasacalciumandnutrientsource,foodsupplementforpoultrydiets,asabarnlimesourcetoneutralizelivestockwaste.Crushedshellisusedasadecorativestone,andoystershelltabletsarewidelyusedasahigh-qualitydietarysupplementandsourceofcalciumandnutrients(suchasiron,copper,iodine,magnesium,etc.)byhumans,andothercommercialbeneficialuses.Pharmaceuticaluseofoystershellcalciumhasalonghistoryofacceptabilityandbenefittohumansasadietarysupplementandnutrientsourceduetoitstexture,digestibility,andsolubility.Calciumasadietarysupplementisanessentialmineralformaintainingteeth,bonedensity(osteoporosis),andproperenzymeactivity.Asaresultoftheseuniquephysicalandchemicalcharacteristicsofoystershellcalciumisalsousedextensivelyasadietarysupplementandcalciumsourceforlivestockandpoultry.AlthoughoystershellminedfromSanFranciscoBayhasbeenusedinthepastforavarietyofpurposes,includingthemanufactureofcement,oystershellminedbyLTBiscurrentlyusedprimarilyasasoilamendmentandasahigh-gradenutrientadditiveforpoultrydiets.Theuniquephysicalpropertiesofoystershellandthemineralcompositionhavebeenfoundtobeespeciallybeneficialasacalciumsourceinpoultrydietstoaidineggshellformation.Theuseofoystershellasacalciumsourceandrationsupplementtoaideggshellqualityandreduceshellbreakagehasbeentestedincomparisontoconventionallimestoneasadietarysupplement(B.Spiller,CaliforniaPolytechnicStateUniversity).Theuseofoystershellasthesourceofdietarycalciumandothernutrientswasfoundtoincreaseeggproduction,extendtheegglayingduration,increaseeggshelldurabilityandreduceshellbreakage,andincreaseeggsizeandqualitywhencomparedtolimestonesupplements.Calciumderivedfromoystershellhasbeenfoundtobeasuperiornutrientandmineralsourcewhencomparedtoinorganiclimestoneandothersources.SanFranciscoBayistheonlyhistoricdepositofoystershellthatiscurrently(since1962)minedcommerciallyinCalifornia.LTBhasinvestigatedthepotentialtouseoystershellfromcommercialoysterproducerswithinthePacificNorthwestandelsewhereasanalternativesourceofoystershelltominingwithinthebay.Resultsoftheseinvestigationshaveshownthatthequantitiesofoystershellavailablefromcommercialoysterproducersarenotadequatetomeettheexistingorfuturemarketdemand.

LindTugandBarge,Inc.-UpdatedProjectDescription-OysterShellMininginSouthSanFranciscoBayTherefore,therearenoalternativecurrentorhistoricoystershellsourceswithinCaliforniatomeetmarketdemand.Asdescribedpreviously,oystershellminingoccurswithintheCaliforniaStateLandsCommission(CSLC)designatedleaseareaPRC5534.1,locatedinSouthSanFranciscoBayadjacenttotheSanMateoBridge(Figure1-1).Theleaseareaisapproximately1,560acresinsize(Figure1-2)withinashallow(waterdepthsaretypically15feetorless),openwatersubtidalareaofthebay.TheprojectwasanalyzedunderCEQAandaMitigatedNegativeDeclaration(MND)preparedandcertifiedbyCSLCinDecember2018(LindTugandBarge,Inc.OysterShellMiningProject,CSLCMND#795,StateClearinghouseNumber#2018062075).LTBiscurrentlylimitedbytheCSLCleaseandotherregulatorypermitstoannualharvestvolumesof80,000cubicyards.LTBproposestocontinueharvestofoystershellsatorbelowthislimitfortheremainderofthetermoftheCSLClease(through2028),thenplansrenewaloftheleaseatthattime.

Figure1-1–OysterShellMiningVicinityMap


Figure1-2–OysterShellCSLCLeaseDetails

1.3. OysterShellMiningMethodsandEquipment

1.3.1. OysterShellMiningMethodsandEquipmentLTBminesoystershelldepositsusingahydraulicsuctiondredge,whichminesandwashestheshell,thenplacestheshellintoanadjacenthopperbarge.Historically,theTug/OysterShellDredge"SOUTHBAY"anditsoystershellbarge(Figure1-3)wereused.TheSOUTHBAY,originallycalleda"BSP"(bargeselfpropelled),wasconstructedforserviceintheAleutianIslandsinthe1940's,thenmodifiedinthe1960'sforserviceasanoystershelldredge.Thiswoodenvesselwasrecentlyretiredattheendof2013,andanewshelldredge,customdesignedexclusivelytoharvestoystershellsfromSouthSanFranciscoBay,wasplacedintoservice(Figure1-4).ThisnewshelldredgeemploysthesameminingandwashingmethodsastheSOUTHBAY,butwithnewerandmoreefficientequipment.


Figure1-3:HistoricShellTug/Dredge“SOUTHBAY”

Figure1-4:NewShellDredgeEngagedinDredging

LindTugandBarge,Inc.-UpdatedProjectDescription-OysterShellMininginSouthSanFranciscoBayTheshelldredgeharvestsoystershellusingthe"trailingsuctionmethodoftrolling"(Figure1-5).Atugboatisusedtopushtheshelldredgeandshellhopperbargetotheleasearea,andtopropelthebargesasminingoccurs.Shelldepositsareminedfromnearthesubstratesurface(typicallywithinapproximately2-3feetofthesurface)byslowingtrollingoverthedepositswithintheleaseareabetween1-2nauticalmilesperhour(knots).

Figure1-5: Schematicdiagramof“trailingsuctiontrolling”methodusedbyLindTugandBargewhileshelldredging.


Figure1-6:OysterShellMiningEquipmentSource:LTB/CSLCMitigatedNegativeDeclaration

2.0 Project Description

June 2018 2-3 Lind Tug and Barge, Inc. Oyster Shell Mining Project MND

Figure 2-3. Equipment Used in Oyster Shell Mining

[A] Current Dredge Suction Pipe, Drag Head

(Left) and

Washed Oyster Shell Conveyor

(Right)

[B] Rotating

Trommel Screen for Washing and

Screening Oyster Shell

[C] Fish Screen Mounted on Suction Pipe


Figure1-6(cont):OysterShellMiningEquipmentSource:LTB/CSLCMitigatedNegativeDeclaration

2.0 Project Description

Lind Tug and Barge, Inc. Oyster Shell Mining 2-4 June 2018 Project MND

Figure 2-3. Equipment Used in Oyster Shell Mining

[D] Dual Fish Screen Assembly Used for Rinse Water

[E] Conceptual Fish Screen Design

with Diesel Engine, Electric

Motor, Centrifugal

Pump, and Rinse Water Intake

Hose

(Side and Front Views)

LindTugandBarge,Inc.-UpdatedProjectDescription-OysterShellMininginSouthSanFranciscoBayDuringmining,a12”diametersuctionpipeequippedwitha24-inchx32-inchdraghead(Figure1-6ALeft)isloweredtothebottom(waterdepthsintheminingareatypicallyrangefrom8-15feetdeep)andintothesubstrateapproximately2-3feetbelowthesurface(reducingpotentialentrainmentofspecies).Thesuctionpipeismountedonthesideofthebargeandraisedandloweredbyanelectricwinch.Thesuctionisconnectedtotheshellpump(12inchdiameterpumpingapproximately6,000gpm),whichtransportsashell,water,andsiltslurryfromthebaybottomuptothebarge.Theslurrycontainsapproximately50percentshell,45percentwater,and5percentsilt;theratiosvarydependingoncharacteristicsofthelocalizedshell-sedimentdeposits.Mostofthewaterusedtomaketheslurryisdrawnthroughtheintersticesoftheshellsubstrateitself;however,asmall4-inchdiameterlineontopofthedragheadenableswaterfromabovethesubstratetoenterthedragheadtofacilitateformationoftheslurry.Toprotectagainstentraininganyadultorjuvenilefishorotherorganismsintothedragheadthroughthisline,asinglestationarypositivebarriercylindricalfishscreenismountedonthesuctionpipe(Figure1-6C).Theslurryispumpedtotheraisedrearofalargerotatingtrommelscreenforwashingandscreening(Figure1-6B).Inthetrommelscreen,additionalwaterisaddedthroughspraybars.Theadditionalwashwaterissuppliedfromawashpump(12inchdiameterpumpingapproximately3,700gpm)throughanintakehosethroughthesideofthebarge.Thisintakeisequippedwithapairofstationarypositivebarriercylindricalfishscreens(Figure1-6D&E).Asthetrommelrotates,siltfallsfromtheshells,andthewaterandsiltreleasebacktotheBaythroughapipeextendingthroughthebottomoftheshelldredge(approximately5feetunderwater).Excesswaterandsiltreleasedinthismannerresultsinalocalizedsuspendedsedimentplumeduringmining.Thesuspendedsedimentconcentrationsandaerialextentoftheplumevarybasedonanumberoffactorsincludingthequantityofsiltandmudassociatedwithaspecificshelldeposit,tidalcurrents,andnaturallyoccurringambientsuspendedsedimentconcentrationwithintheSouthBayintheareawhereminingoccurs.Thewashedshellisthenconveyedtoahopperbargefromthetrommelusinga24”conveyorbelt(Figure1-6ARight).Thebargeiskept"trim"(level)atalltimesbymovingtheconveyorfromsidetoside,andbyre-positioningthebargenexttotheshelldredge.Oncethehopperbargeisloaded,thetugboatpushestheloadedbargeandshelldredgetoMareIslandinVallejo,wherethedredgeismooredbetweenminingevents.TheloadedhopperbargeistransportedbytugtooneoftwoshellprocessingsitesinPetalumaonthePetalumaRiverorCollinsville(alongMontezumaSloughupstreamofSuisunBay),operatedbyanaffiliateofLTB,LindMarineIncorporated(LMI).Attheoffloadsite,ahydraulicexcavatorisusedtoscooptheshellfromthehopperbargetoaconveyorsystemthatstockpiletheshellforprocessingattheprocessingfacility(seeFigures1-7,1-8).TheprocessedshellisbaggedorloadedintobulktrucksfordistributiontoaccommodatemarketdemandfortheshellproductinCaliforniaandthewesternU.S.


Figure1-7.Shorestockpileofoystershells.

Figure1-8.Closeupofoystershells.

LindTugandBarge,Inc.-UpdatedProjectDescription-OysterShellMininginSouthSanFranciscoBay1.4. CharacteristicsofOysterShellMiningEvents

1.4.1. SpatialDistribution/DepthofMiningEventsOystershellminingdoesnotoccuruniformlythroughouttheentireleasearea.Miningislimited,inpart,byshallowwaterdepthsoccurringwithinportionsoftheleasearea,whichprecludesignificantminingactivitiesunlesstimingoftheeventcoincideswithhightide.Therefore,miningactivitiesoccurmorefrequentlyinthedeeperwaterportionsoftheleasearealocatedalongthewesternborderoftheleasewherewaterdepthsatMLLWtypicallyrangefrom7to13feet.AsaresultofwindfetchoccurringwithinthesouthBay,shallowerareaswithintheleasearetypicallycharacterizedbyhigherwavesandmoredifficultconditionstoeffectivelyconductshellmining.Oystershellharvestisthereforefunctionallylimitedtothoseareasoftheleasewherewaterdepthsaregreaterandwaveactivityisreduced,therebyallowingmoreefficientharvest.Tohelpassesscurrentbathymetricconditionswithintheleaseareaandchangestobathymetricconditions,periodicbathymetrysurveyshavebeenconductedintheleasearea.AppendixAincludestheresultsofthesesurveys,whichincludetheresultsofasingle-beamsurveyoftheleaseconductedinearly2014byBayMarineServices.ThesurveyrepresentsdepthsrelativetoMLLWintheleasearea.AppendixAalsoincludesdatafroma2005single-beambathymetrysurveyconductedundercontractwiththeU.S.GeologicalSurvey(USGS),andplottedbyeTracEngineeringLLCwiththeleaseareaoverlaidin2007.Notethatthe2005surveyshowsdepthsinmeters,andthe2014surveyshowsdepthsinfeet.Comparisonbetweenthesesurveysshowsthatsomeportionsoftheleaseareaexperiencedonlyminorchangesinbathymetry.Thewesternareaoftheleasewhereminingmostlyoccursshowsaslightincreaseindepth(0-2feet);howeverareaswhereminingdoesnottypicallyoccurasloshowedslightchangesinbathymetry,soactualpotentialeffectsofminingarenotclearofconclusivebasedonthesesurveys.(CSCLMND,2018)Tocontinuetodevelopinformationonbathymetrictrends,LTBproposedtoconductongoingperiodicbathymetricsurveysbeginningin2019,thenin2022and2026tobetterevaluatebathymetrictrendsintheleasearea.AsurveywasconductedbyeTracEngineeringinOctober2019;theseresultsarealsoshowninAppendixA.Comparisonwiththislatestsurveyisbeingconductedcurrently,andwillbeprovidedwhenitiscomplete.

1.4.2. TemporalDistributionandDurationofMiningEpisodesShellminingactivitymayoccuratanytimeoftheday,dependingontides,currents,winds,weather,thesizeofthehopperbargebeingloaded,intermittentdelays/breakdowns,transittimestothelease,etc.Actualminingandpumpingdurationwiththecurrentdredgeconfigurationaveragesapproximately80percentofthetotaltimeofoperation.Transittimebetweentheleaseareaandoneofthetwo

LindTugandBarge,Inc.-UpdatedProjectDescription-OysterShellMininginSouthSanFranciscoBayland-basedfacilities(PetalumaorCollinsville)isapproximately8hours(emptybarge)to12hours(loadedbarge)onewaydependingontheonshorefacilityused.Ittakes6hourstoover24hourstofillabargedependingonthesizeofthebarge,and6-8hourstooffloadatthedeliverysite.Productdemanddictatesthefrequencyandnumberofminingeventsthatoccur.Limitedland-basedstorageofminedshellproductanddemanddictatetheminingeventfrequency.Useofnew,moreefficientequipmentandlargervolumebargeshasresultedinfewerminingeventsneededtomeetdemand,eventhoughthedurationofindividualeventshasincreased.Forexample,theestimatednumberofminingeventsrequiredtomine80,000c.y.ofshellisasfollows:thehistoricaldredgeSouthBayoperationsrequiredapproximately91miningeventsover910hoursannually;newminingequipmentandbargeconfigurationsrequireonlyabout28miningeventsoveranestimated409hourstominethemaximumannualvolumes.Thesereductionsintimeandnumberofminingeventsresultinfewerlocaltemporaldisturbances,andsignificantlylowerfuelconsumptionandassociatedairemissionsassociatedwithvesseltransitandminingcomparedtothehistoricoperations.

1.4.3. MiningVolumesandSeasonalDistributionTheamountandseasonaltimingofminingvolumesarelargelydictatedbydemandforshellproduct;seasonalityhasverylittleinfluence,asthemajorityoftheproductisusedforagriculturalfeedsupplement.Miningvolumesmayalsobeindirectlylimitedbythemaximumcubicyardageallowedundertherespectiveleasesandpermits.Thecurrentannualpermittedvolumesofshellthatcanbeharvestedfromtheshellleaseis80,000c.y.(40,000tons).Table1-1showstheactualannualvolumesofshellminedbyLTBfrom2006-2019.Table1-2illustratestheactualaveragemonthlyvolumedistributionfortheperiod2006-2017,andaprojectedfuturedistributionofminingeventsforatotalannualvolumeof80,000c.y.TheproposedprojectevaluatedinthisITPapplicationisbasedonarelativelyflatseasonaldistributionofvolumes,andatotalannualvolumeofupto40,000tons/80,000cubicyards.Seasonaldistributionfrom2006-2017wasrelativelyconstant,withmonthlytotalsrangingbetween6.4and10.5%oftotalannualvolumes.Forfutureevents,LTBproposestoaltertheseasonaldistributionofminingepisodestoavoidsensitivespawningperiodsforlongfinsmeltandthepresenceoftheirlarvaeintheminingareabyceasingminingfortwofullmonthsduringaperiodbetweenFebruaryandJuneofeachyear.LTBproposestoceaseminingactivityinthesemonthstopreventlarvalorlifestageofthesespeciesofconcernwithintheSouthBayfrombeingentrainedthroughminingactivity.TheactualtwomonthcurtailmentperiodwillbeselectedeachyearbyJanuary31throughnoticetoCDFW.Miningwouldbespreadthroughouttheremainingmonths,withperiodsofinventorybuildupandrecoveryifrequiredtomaintainappropriateofshell.


Table1-1.ActualShellMiningVolumes–2006-2019

YEAR

TONSMINED

CUBICYARDS

MINED

#OFMININGEPISODES

2006 32,771 65,542 672007 31,809 63,618 612008 29,916 59,832 592009 27,758 55,516 542010 33,108 66,216 612011 31,255 62,510 592012 33,196 66,392 682013 36,017 72,034 642014 32,394 64,788 502015 29,509 59,018 312016 30,838 61,676 342017 26,120 52,240 182018 24,115 48,230 162019 22,485 44,970 13

Table1-2.Average/ProjectedLTBMonthlyMiningVolumes

Month

AvgVolumes(2006-2017) ProjectedFutureVolumes

tonsCubicyards

%AnnualTotal

tons

Cubicyards

%AnnualTotal

Jan 3,066 6,132 9.8 6,240 12,480 15.6Feb 3,287 6,574 10.5 0 0 0Mar 2,486 4,972 8.0 0 0 0Apr 2,573 5,146 8.2 6,240 12,480 15.6May 2,491 4,982 8.0 2,560 5,120 6,4Jun 2,958 5,916 9.5 6,240 12,480 15.6Jul 2,554 5,108 8.2 0 0 0Aug 3,035 6,070 9.7 6,240 12,480 15.6Sep 2,060 4,120 6.6 0 0 0Oct 2,370 4,740 7.6 6,240 12,480 15.6Nov 1,986 3,972 6.4 0 0 0Dec 2,358 4,716 7.6 6,240 12,480 15.6

TOTAL 31,224 62,448 100.0 40,000 80,000 100.0

updated project description commercial oyster shell mining ... · oyster shell was harvested as...

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