Contech Filterra Troubleshooting guide

Operation & Maintenance
(OM) Manual v01
®
Bioretention Systems
ENGINEERED SOLUTIONS

www.ContechES.com/filterra | 800-338-1122
Table of Contents
Overview
•Filterra®GeneralDescription
•Filterra®Schematic
•BasicOperations
•Design
Maintenance
•MaintenanceOverview
»WhyMaintain?
»WhentoMaintain?
•ExclusionofServices
•MaintenanceVisitSummary
•MaintenanceTools,SafetyEquipmentandSupplies
•MaintenanceVisitProcedure
•MaintenanceChecklist
®
Bioretention Systems
ENGINEERED SOLUTIONS

www.ContechES.com/filterra | 800-338-1122
General Description
ThefollowinggeneralspecificationsdescribethegeneraloperationsandmaintenancerequirementsfortheContech
EngineeredSolutionsLLCstormwaterbioretentionfiltrationsystem,theFilterra®.Thesystemutilizesphysical,chemical
andbiologicalmechanismsofasoil,plantandmicrobecomplextoremovepollutantstypicallyfoundinurbanstormwater
runoff.Thetreatmentsystemisafullyequipped,pre-constructeddrop-inplaceunitdesignedforapplicationsintheurban
landscapetotreatcontaminatedrunoff.
Stormwaterflowsthroughaspeciallydesignedfiltermediamixturecontainedinalandscapedconcretecontainer.The
mixtureimmobilizespollutantswhicharethendecomposed,volatilizedandincorporatedintothebiomassoftheFilterra®
system’smicro/macrofaunaandflora.Stormwaterrunoffflowsthroughthemediaandintoanunderdrainsystematthe
bottomofthecontainer,wherethetreatedwaterisdischarged.HigherflowsbypasstheFilterra®toadownstreaminletor
outfall.Maintenanceisasimple,inexpensiveandsafeoperationthatdoesnotrequireconfinedspaceaccess,pumpingor
vacuumequipmentorspecializedtools.ProperlytrainedlandscapepersonnelcaneffectivelymaintainFilterra®Stormwater
systemsbyfollowinginstructionsinthismanual.

www.ContechES.com/filterra | 800-338-1122
Basic Operations
Filterra®isabioretentionsysteminaconcretebox.
Contaminatedstormwaterrunoffentersthefilterboxthrough
thecurbinletspreadingoverthe3-inchlayerofmulchonthe
surfaceofthefiltermedia.Asthewaterpassesthroughthe
mulchlayer,mostofthelargersedimentparticlesandheavy
metalsareremovedthroughsedimentationandchemical
reactionswiththeorganicmaterialinthemulch.Waterpasses
throughthesoilmediawherethefinerparticlesareremoved
andotherchemicalreactionstakeplacetoimmobilizeand
capturepollutantsinthesoilmedia.Thecleansedwater
passesintoanunderdrainandflowstoapipesystemor
otherappropriatedischargepoint.Oncethepollutantsare
inthesoil,thebacteriabegintobreakdownandmetabolize
thematerialsandtheplantsbegintouptakeandmetabolize
thepollutants.Somepollutantssuchasheavymetals,which
arechemicallyboundtoorganicparticlesinthemulch,are
releasedovertimeastheorganicmatterdecomposesto
releasethemetalstothefeederrootsoftheplantsandthe
cellsofthebacteriainthesoilwheretheyremainandare
recycled.Otherpollutantssuchasphosphorusarechemically
boundtothesoilparticlesandreleasedslowlybacktothe
plantsandbacteriaandusedintheirmetabolicprocesses.
Nitrogengoesthroughaverycomplexvarietyofbiochemical
processeswhereitcanultimatelyendupintheplant/bacteria
biomass,turnedtonitrogengasordissolvesbackintothe
watercolumnasnitratesdependingonsoiltemperature,pH
andtheavailabilityofoxygen.Thepollutantsultimatelyare
retainedinthemulch,soilandbiomasswithsomepassingout
ofthesystemintotheairorbackintothewater.
Design and Installation
Eachprojectpresentsdifferentscopesfortheuseof
Filterra®systems.Toensurethesafeandspecifiedfunction
ofthestormwaterBMP,Contechreviewseachapplication
beforesupply.Informationandhelpmaybeprovidedto
thedesignengineerduringtheplanningprocess.Correct
Filterra®boxsizing(byrainfallregion)isessentialtopredict
pollutantremovalratesforagivenarea.Theengineershall
submitcalculationsforapprovalbythelocaljurisdiction.
Thecontractorisresponsibleforthecorrectinstallationof
Filterraunitsasshowninapprovedplans.Acomprehensive
installationmanualisavailableatwww.conteches.com.
Maintenance
Why Maintain?
Allstormwatertreatmentsystemsrequiremaintenancefor
effectiveoperation.Thisnecessityisoftenincorporatedin
yourproperty’spermittingprocessasalegallybindingBMP
maintenanceagreement.
•Avoidlegalchallengesfromyourjurisdiction’s
maintenanceenforcementprogram.
•ProlongtheexpectedlifespanofyourFilterramedia.
•Avoidmorecostlymediareplacement.
•Helpreducepollutantloadsleavingyourproperty.
SimplemaintenanceoftheFilterra®isrequiredtocontinue
effectivepollutantremovalfromstormwaterrunoffbefore
dischargeintodownstreamwaters.Thisprocedurewillalso
extendthelongevityofthelivingbiofiltersystem.Theunitwill
recycleandaccumulatepollutantswithinthebiomass,but
isalsosubjectedtoothermaterialsenteringthethroat.This
mayincludetrash,siltandleavesetc.whichwillbecontained
withinthevoidbelowthetopgrateandabovethemulch
layer.ToomuchsiltmayinhibittheFilterra’s®flowrate,
whichisthereasonforsitestabilizationbeforeactivation.
Regularreplacementofthemulchstopsaccumulationofsuch
sediment.
When to Maintain?
Contechincludesa1-yearmaintenanceplanwitheach
systempurchase.Annualincludedmaintenanceconsistsofa
maximumoftwo(2)scheduledvisits.Additionalmaintenance
maybenecessarydependingonsedimentandtrashloading
(byOwneroratadditionalcost).Thestartofthemaintenance
planbeginswhenthesystemisactivatedforfulloperation.
Fulloperationisdefinedastheunitinstalled,curbandgutter
andtransitionsinplaceandactivation(bySupplier)when
mulchandplantareaddedandtemporarythroatprotection
removed.
Activationcannotbecarriedoutuntilthesiteisfullystabilized
(fulllandscaping,grasscover,finalpavingandstreetsweeping
completed).Maintenancevisitsarescheduledseasonally;the
springvisitaimstocleanupafterwinterloadsincludingsalts
andsandswhilethefallvisithelpsthesystembyremoving
excessiveleaflitter.
Ithasbeenfoundthatinregionswhichreceivebetween30-50
inchesofannualrainfall,(2)twovisitsaregenerallyrequired;
regionswithlessrainfalloftenonlyrequire(1)onevisitper
annum.Varyinglandusescanaffectmaintenancefrequency;
e.g.somefastfoodrestaurantsrequiremorefrequenttrash
removal.Contributingdrainageareaswhicharesubjecttonew
developmentwhereintherecommendederosionandsediment
controlmeasureshavenotbeenimplementedmayrequire
additionalmaintenancevisits.
Somesitesmaybesubjectedtoextremesedimentortrash
loads,requiringmorefrequentmaintenancevisits.Thisisthe
reasonfordetailednotesofmaintenanceactionsperunit,
helpingtheSupplierandOwnerpredictfuturemaintenance
frequencies,reflectingindividualsiteconditions.
Ownersmustpromptlynotifythe(maintenance)Supplierof
anydamagetotheplant(s),whichconstitute(s)anintegralpart
ofthebioretentiontechnology.Ownersshouldalsoadvise
otherlandscapeormaintenancecontractorstoleaveall
maintenancetotheSupplier(i.e.nopruningorfertilizing).

www.ContechES.com/filterra | 800-338-1122
Exclusion of Services
ItistheresponsibilityoftheownertoprovideadequateirrigationwhennecessarytotheplantoftheFilterra®system.
Cleanupduetomajorcontaminationsuchasoils,chemicals,toxicspills,etc.willresultinadditionalcostsandarenot
coveredundertheSuppliermaintenancecontract.ShouldamajorcontaminationeventoccurtheOwnermustblockoffthe
outletpipeoftheFilterra®(wherethecleanedrunoffdrainsto,suchasdropinlet)andblockoffthethroatoftheFilterra®.
TheSuppliershouldbeinformedimmediately.
Maintenance Visit Summary
Eachmaintenancevisitconsistsofthefollowingsimpletasks(detailedinstructionsbelow).
1.InspectionofFilterra®andsurroundingarea
2.Removaloftreegrateanderosioncontrolstones
3.Removalofdebris,trashandmulch
4.Mulchreplacement
5.Planthealthevaluationandpruningorreplacementasnecessary
6.CleanareaaroundFilterra®
7.Completepaperwork
Maintenance Tools, Safety Equipment and Supplies
Idealtoolsinclude:camera,bucket,shovel,broom,pruners,hoe/rake,andtapemeasure.AppropriatePersonalProtective
Equipment(PPE)shouldbeusedinaccordancewithlocalorcompanyprocedures.Thismayincludeimperviousgloves
wherethetypeoftrashisunknown,highvisibilityclothingandbarricadeswhenworkingincloseproximitytotrafficand
alsosafetyhatsandshoes.AT-Barorcrowbarshouldbeusedformovingthetreegrates(upto170lbsea.).Mostvisits
requireminortrashremovalandafullreplacementofmulch.Seebelowforactualnumberofbaggedmulchthatis
requiredineachunitsize.Mulchshouldbeadoubleshredded,hardwoodvariety;donotusecoloredordyedmulch.Some
visitsmayrequireadditionalFilterra®engineeredsoilmediaavailablefromtheSupplier.
BoxLength BoxWidth FilterSurface
Area(ft²)
Volumeat3”
(ft³)
#of2ft³Mulch
Bags
4 4 16 42
6 4 24 63
8 4 32 8 4
6 6 36 95
8 6 48 12 6
10 660 15 8
12 672 18 9
13 791 23 12

www.ContechES.com/filterra | 800-338-1122
Maintenance Visit Procedure
Keepsufficientdocumentationofmaintenanceactionstopredictlocation
specificmaintenancefrequenciesandneeds.AnexampleMaintenanceReport
isincludedinthismanual.
1. Inspection of Filterra® and surrounding area
•Recordindividualunitbeforemaintenancewithphotograph(numbered).
RecordonMaintenanceReport(seeexampleinthisdocument)the
following:
2. Removal of tree grate and erosion control stones
•RemovecastirongratesforaccessintoFilterra®box.
•Digoutsilt(ifany)andmulchandremovetrash&foreignitems.
3. Removal of debris, trash and mulch
•Afterremovalofmulchanddebris,measuredistancefromthetopof
theFilterra®engineeredmediasoiltothebottomofthetopslab.Ifthis
distanceisgreaterthan12”,addFilterra®media(nottopsoilorother)to
rechargetoa9”distance
RecordonMaintenanceReportthefollowing:
StandingWater yes|no
DamagetoBoxStructure yes|no
DamagetoGrate yes|no
IsBypassClear yes|no
Ifyesansweredtoanyoftheseobservations,record
withclose-upphotograph(numbered).
RecordonMaintenanceReportthefollowing:
Silt/Clay yes|no
Cups/Bags yes|no
Leaves yes|no
#ofBucketsRemoved ________
RecordonMaintenanceReportthefollowing:
DistanceofBottomofTopSlab(inches) ________
#ofBucketsofMediaAdded ________

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4. Mulch replacement
•Pleaseseemulchspecifications.
•Adddoubleshreddedmulchevenlyacrosstheentireunittoadepthof3”.
•EnsurecorrectrepositioningoferosioncontrolstonesbytheFilterra®inlet
toallowforentryoftrashduringastormevent.
•ReplaceFilterra®gratescorrectlyusingappropriateliftingormovingtools,
takingcarenottodamagetheplant.
5. Plant health evaluation and pruning or replacement
as necessary
•Examinetheplant’shealthandreplaceifdead.
•Pruneasnecessarytoencouragegrowthinthecorrectdirections
6. Clean area around Filterra®
•Cleanareaaroundunitandremoveallrefusetobedisposedof
appropriately.








7. Complete paperwork
•DeliverMaintenanceReportandphotographstoappropriatelocation
(normallyContechduringmaintenancecontractperiod).
•Somejurisdictionsmayrequiresubmissionofmaintenancereportsin
accordancewithapprovals.ItistheresponsibilityoftheOwnertocomply
withlocalregulations.
RecordonMaintenanceReportthefollowing:
HeightaboveGrate ________________(ft)
WidthatWidestPoint ________________(ft)
Health alive|dead
DamagetoPlant yes|no
PlantReplaced yes|no

www.ContechES.com/filterra | 800-338-1122
Maintenance Checklist
DrainageSystem
Failure Problem ConditionstoCheck ConditionthatShouldExist Actions
Inlet
Excessive
sedimentortrash
accumulation.
Accumulatedsediments
ortrashimpairfreeflow
ofwaterintoFilterra.
Inletshouldbefreeof
obstructionsallowingfree
distributedflowofwater
intoFilterra.
Sedimentsand/ortrash
shouldberemoved.
MulchCover
Trashand
floatabledebris
accumulation.
Excessivetrashand/or
debrisaccumulation.
Minimaltrashorother
debrisonmulchcover.
Trashanddebrisshould
beremovedandmulch
coverrakedlevel.Ensure
barknuggetmulchisnot
used.
MulchCover
“Ponding”of
wateronmulch
cover.
“Ponding”inunitcould
beindicativeofclogging
duetoexcessivefine
sedimentaccumulation
orspillofpetroleumoils.
Stormwatershoulddrain
freelyandevenlythrough
mulchcover.
Recommendcontact
manufacturerand
replacemulchasa
minimum.
Vegetation
Plantsnot
growingorin
poorcondition.
Soil/mulchtoowet,
evidenceofspill.
Incorrectplantselection.
Pestinfestation.
Vandalismtoplants.
Plantsshouldbehealthy
andpestfree.
Contactmanufacturer
foradvice.
Vegetation Plantgrowth
excessive.
Plantsshouldbe
appropriatetothe
speciesandlocationof
Filterra.
Trim/pruneplantsin
accordancewithtypical
landscapingandsafety
needs.
Structure Structurehas
visiblecracks.
Crackswiderthan1/2
inchorevidenceofsoil
particlesenteringthe
structurethroughthe
cracks.
Vaultshouldberepaired.
Maintenance is ideally to be performed twice annually.
ENGINEERED SOLUTIONS
©2015ContechEngineeredSolutionsLLC
Revised6/22/2015