Massachusetts Erosion and Sedimentation Control Guidelines

8/11/2019 Massachusetts Erosion and Sedimentation Control Guidelines

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Massachuse t t s

Erosion and Sediment Control Guidelines for Urban and Suburban Areas

A Guide

for

Planners,

Designers,

and

Municipal

Officials

Department of Environmental

Protection, Bureau of Resource

Protection, One Winter Street 5th floor,

Boston, MA 02108
http://www.state.ma.us/dephttp://www.state.ma.us/dephttp://www.state.ma.us/dephttp://www.state.ma.us/dephttp://www.state.ma.us/dep


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MASSACHUSETTS EROSION AND SEDIMENT CONTROL GUIDELINES FOR

URBAN AND SUBURBAN AREAS

AGuidefor Planners,

Designersand MunicipalOfficials

OriginalPrint:March1997

Reprint: May 2003

originallypreparedfor:

Massachusetts Executive Office of Environmental Affairs

StateCommissionforConservationofSoil, WaterandRelatedResources

MassachusettsDepartmentofEnvironmentalProtection BureauofResourceProtection

U.S.EnvironmentalProtectionAgency Region1

NaturalResourcesConservationService

UnitedStatesDepartmentofAgriculture

originallypreparedby:

Franklin, Hampden, Hampshire Conservation Districts

243KingStreet-Room39Northampton,MA01060

ThisprojecthasbeenfinancedpartiallywithFederalfundsfromtheEnvironmentalProtectionAgency(EPA)tothe

MassachusettsDepartmentofEnvironmentalProtection(DEP)undera319NonpointSourceCompetitiveGrant.ThecontentsdonotnecessarilyreflecttheviewsandpoliciesofEPAorofDEP,nordoesthementionoftradenamesor

commercialproductsconstituteendorsementorrecommendationforuse.

ExecutiveOfficeofEnvironmentalAffairs

EllenRoyHerzfelder,Secretary DepartmentofEnvironmentalProtection

EdKunce,ActingCommissioner BureauofResourceProtection

CynthiaGiles,AssistantCommissioner

DivisionofWatershedManagement GlennHaas,Director


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PrefaceIn1975,theSoilConservationService,USDA,inMassachusettspublishedthefirsteditionofthe

Guidelines for Soil and Water Conservation in Urbanizing Areas of Massachusetts.Thiswasa300+pagebookdealingwithawidevarietyofconservation-relatedurbanproblemsandsituationsencountered

throughoutthestateofMassachusetts.

Afterthethirdprintingandin1982,theSoilConservationServicebegananupdateandrevisiontobringthisvolumeuptodate.Atthesametime,theformatwaschangedfromasinglevolumetoaseriesof

Massachusetts Conservation Guides-eachkeyedtoaspecificsubjectarea.Onlythefirsttwooftheproposedfiveguideswerepublished:Volume I - Erosion & Sediment Control in Site Development andVolume II - Vegetative Practices in Site Development.

Inlate1993,realizingtheneedforacomplete,up-to-datevolumeforpersonsundertakingtoplan,installorreviewurbandevelopmentsinthestate,theStateCommissionforConservationofSoil,WaterandRelatedResourcestooktheleadtoprepareacompleteandcomprehensiverevisionofthishandbook.TheCommissionenlistedtheaidoftheExecutiveOfficeofEnvironmentalAffairs,theMassachusetts

DepartmentofEnvironmentalProtection,andtheNaturalResourcesConservationServices(formerlytheSoilConservationService)oftheU.S.DepartmentofAgriculture.Thisgroup,workingthroughtheFranklin,Hampden,HampshireConservationDistricts-DivisionV,undertooktoupdatetheoriginaldocumentandthisvolumeistheculminationoftheirefforts.

Therearenumerousexcellentreferencesavailabletothegeneralpubliccoveringthefieldsoferosionandsedimentcontrol,pollutioncontrol,andstormwatermanagement.Thisguidedrawsuponmanyof

thosedocuments.ItismeanttoprovidethelaypersonwhoisinvolvedinprojectswhichaffectthelandandwaterresourcesinMassachusettswithbackgroundinformation.Furtherdetailsmaybefoundinotherdocuments,whicharereferencedassourcesofinformation.

Thisguidedealsprimarilywithconservationmeasuresandconservationpractices.ThesepracticesaregenerallyreferredtoasBest Management Practices orBMPsandisintendedtobeacompanionhandbookwiththerecentlypreparedMega-ManualpreparedbytheMassachusettsDepartmentofEnvironmentalProtection.

Onlylimiteddetailisincludedaboutthesoils,engineering,hydrology,plantmaterialsandotherknowledgethatisneededtoplananddesignapotentialproject.Itisintendedonlyasaguideandshouldbe

usedassuch.Aprofessionalplannershouldbeengagedtopreparetheproposalandaprofessionalengineerforthedetailederosionandsedimentcontrolplananddesigns,drawings,andspecifications.

Thecontentsofthisguidearebasedonmaterialalmostentirelyinthepublicdomain,publishedby

federalorstateagenciesorpubliceducationalinstitutions.Itshouldnotbeinterpretedasnecessarily

representingthepoliciesorrecommendationsofotherreferencedagenciesororganizationsnoroftheagencieswhosponsoredthisrevision.Thementionoftradenames,products,companiesorpublications

doesnotconstituteanendorsement,butareusedforclarification.

Inthefallof1994,theUSDASoilConservationServicewasrenamedtheNaturalResourcesConservationService.NumerousreferencesusedhereinwerepublishedasSoilConservationService

documentsandhavenotbeenrenamedorrevisedatthisdate.


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Acknowledgements

Thefollowingindividualswereinstrumentalinguidingthedevelopmentofthisguide:

ThomasAndersonoftheStateCommissionforConservationofSoil,WaterandRelatedResourcesfor

hisassistanceinobtainingfundsandcoordinatingthereviewofthedraftdocumentswithotherstateagencies.

WilliamP.Annable,P.E.,forcollectingmaterialsandrelatedinformation,revisingandupdatingthe

previouslypreparededitionsofthehandbookandupdatingandpreparingthisversionoftheGuidelines.

JohnBennettoftheFranklinConservationDistrictforhisassistanceinreviewingandcommentingon

thedraftdocuments.

RussellCohenoftheMassachusettsRiverwaysProgramforhisassistanceinreviewingandcommentingonthedraftdocuments.

RichardDeVergiliooftheNaturalResourcesConservationService,USDAforhisassistanceincollecting,editingandpreparingplantmaterialsinformationforthevarioussectionsofthehandbook.

CarlGustafsonoftheNaturalResourcesConservationService,USDAforhisassistanceincollectingavailableinformation,coordinatingtheinputsofotherpersonnelfromtheNRCS,andreviewingandcommentingonthedraftdocuments.

GeneMillsoftheFranklin,Hampden,HampshireConservationDistricts-DivisionVforhisworkinpreparingcontractdocuments,handlingthecontractingprocedures,arrangingmeetingsanddocumentreviewsandguidingthisprojecttocompletion.

LeslieOSheaoftheOfficeofWatershedManagement,MassachusettsDepartmentofEnvironmentalProtectionforherassistanceinguidingthepreparationoftheguidethroughthe319processandprovidingcommentsonthedraftdocuments.

KathyRuhfoftheFranklin,Hampden,HampshireConservationDistricts-DivisionVforherassistanceinreviewingandcommentingonthedraftdocuments.

ArthurScrepetisoftheOfficeofWatershedManagement,MassachusettsDepartmentofEnvironmental

Protectionforhisassistanceincompletingthecontractandpublishingthedocument.

JanSmithoftheMassachusettsCoastalZoneManagementprogramforhisassistanceinreviewingandcommentingonthedraftdocument.

GerrySurineroftheFranklin,Hampden,HampshireConservationDistricts-DivisionVOfficeforherworkinpreparingcopies,makingmailings,typingandfilingcontractmaterialsandpreparinganddistributing

materialsanddrafts.KennethTayloroftheHampdenConservationDistrictforhisassistanceinreviewingandcommentingonthedraftdocuments.

MichaelWhalenoftheBerkshireResourceandConservationDevelopmentProjectforhisassistancein

preparingthegrantproposal.


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ThepreparationofthisguidewasfinancedbytheMassachusettsStateCommissionforConservationo

Soil,WaterandRelatedResources;theMassachusettsExecutiveOfficeofEnvironmentalAffairs;theMassachusettsDepartmentofEnvironmentalProtectionthroughfundsfromtheUnitedStatesEnvironmentalProtectionAgencyunderthesection319NonpointSourceCompetitiveGrantProgram;theUnitedStatesDepartmentofAgriculture,NaturalResourcesConservationService;andtheFranklin,

Hampden,HampshireConservationDistricts-DivisionV.

ThisguidewaspublishedwithfinancialassistancefromtheMassachusettsDepartmentof

EnvironmentalProtectionthroughfundsfromtheUnitedStatesEnvironmentalProtectionAgencyunderthesection319NonpointSourceCompetitiveGrantProgramandtheUnitedStatesDepartmentofAgriculture,NaturalResourcesConservationService.


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Table of Contents PagePart I, Principles and Planning 8

ErosionandSedimentation 8

FactorsthatInfluenceErosion 9 EffectsofUrbanization 13 ErosionandSedimentHazardsAssociatedwithSiteDevelopment 15 AnalyzingtheProjectSite 21

PotentialProblems 36 StabilizationPrinciplesforSiteDevelopment 38 DevelopingAnErosionandSedimentControlPlan 42

Part II, Guide to Best Management Practice Selection 54

BestManagementPracticeSelection 54

Sitework:On-siteroads,Controllingroadrunoff 55 ClearingandGrading 56 Excavations,Stockpiles,&Debrisdisposal 56 RillandGullyErosion 57

SedimentControl 57 StormRunoff 58 StreambankProtectionandStabilization 58

StreamCrossings 59 BuildingConstruction,UtilitiesInstallations 59 SpecialSiteProblems 60

60FinalSiteStabilization

62Part III, Erosion and Sediment Control Practices

BrushBarrier 62 BufferZones,StreamCorridors,andRiparianAreas 63 CheckDam 64 ConstructionEntrance 68

ConstructionRoadStabilization 71 Diversion,Permanent 73 Diversion,Temporary 77

DustControl 80 FilterBerm 82 FilterStrip,Vegetated 84 Flume,Paved 86

Gabions 88 Geotextiles 90 GradeStabilizationStructure 92 InletProtection 93

LandGradingandStabilization 102 LevelSpreader 109 MulchandNetting 112

OutletProtectionandStabilization 118 PreservingNaturalVegetation 121 Riprap 125


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Table of Contents Page

Part III, Erosion and Sediment Control Practices (Continued)

RockDam 129

SandDuneandSandblowStabilization 133 SandFence 135 SedimentBasin 138

SedimentFence 146 SedimentTrap 152 Seeding,Permanent 157

Seeding,Temporary 167 SiltCurtain 171 SlopeDrain,Temporary 172 Sodding 176

StraworHayBaleBarrier 181

StreamCrossing,Temporary 185 StreambankProtectionandStabilization 192 SubsurfaceDrain 201

SumpPit 204 SurfaceRoughening 205 Terrace 208

Topsoiling 210 TreeandShrubPlanting 212 VegetatedSwale 215 WaterBar 219

Waterway,Grassed 222 228Waterway,Lined

Part IV, Supplementary Information

Rainfall,Runoff,andLandUseChange 232

Plants,Vegetation,SoilCovers 243 SoilBioengineering 280

Best Management Practices for Individual Homesites and Small

Parcels

Best Management Practices for Sand and Gravel Pits

A Sample Erosion and Sedimentation Control PlanGlossary

Bibliography

Subject Index

232

320

322

329

338

349

354


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8 Principles and Planning

Principles

and

Planning

ErosionandSedimentation

FactorsthatInfluenceErosion

Effectsof

Urbanization

ErosionandSedimentHazards

AssociatedwithSiteDevelopment

AnalyzingtheProjectSite

PotentialProblems

PrinciplesforSite

Development

DevelopinganErosionandSedimentControl

Plan

Erosion and Sedimentation

Asundevelopedareasareconvertedtourbanuses,thenatural

vegetationisremoved,landslopesmaybeexcavatedorfilled,groundsurfacesarepavedover,andstreamchannelsaremodified.Theresultisanincreaseinrunoffandareductionintheabilityofthelandtoprovidenaturaltreatmenttotherunoff.

Landisdisturbedandexposedtoerosionbywindandwaterduring

thisperiodofconversion.Soildisplacedbyerosioncontributestobothonsiteandoffsitedamages.Aportionofthesoilreachesthestatesstreams,lakes,andcoastalwatersassediment.

ErosionErosionisthewearingawayofthelandsurfacebyrunningwater,

wind,ice,orothercauses.Soilerosionisusuallycausedbytheforceofwaterfallingasraindropsandbytheforceofwaterflowinginrillsandstreams.Raindropsfallingonbareorsparselyvegetatedsoildetachsoilparticles.Waterrunningalongthesurfaceofthegroundpicksupthese

particlesandcarriesthemalongasitflowsdownhilltowardsastreamsystem.

Astherunoffgainsinvelocityandconcentration,itdetachesmoresoilparticles,cutsrillsandgulliesintothesurfaceofthesoilandadds

toitssedimentload.Themergingrivuletsproducelargerchannelswhichhavealargervolumeandusuallyhighervelocity,andagreatercapacitytoremovesedimentandtransportitdownstream.

Thegreaterthedistancethewaterrunsuncontrolled,thegreater

itserosiveforceandthegreatertheresultantdamage.Moreover,controlbecomesmoredifficultasthedistanceandvolumeincreases.

Soilerosionisalsocausedbytheforceofwindblowingacross

unprotectedground.Opengravelpitsandconstructionsitesthathavebeenstrippedofvegetationareespeciallyvulnerabletowinderosion.Thewind-bornesedimentslandinstreams,roads,andneighboringlots.Blowingdustisanuisance,andcanbeahazardonespeciallywindy

days.Winderosioninareasundergoingdevelopmentcanbecontrolledbestby

keepingdisturbedareassmallandbystabilizingand

protectingthemassoonaspossible.


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9Principles and Planning

SedimentationSedimentationisthedepositionofsoilparticlesthathavebeen

transportedbywaterandwind.Thequantityandsizeofthematerialtransportedincreaseswiththevelocity.Sedimentationoccurswhenthe

medium,airorwater,inwhichthesoilparticlesarecarriedissufficientlyslowedlongenoughtoallowparticlestosettleout.Heavierparticles,suchasgravelandsand,settleoutsoonerthandofinerparticles,suchasclay.

Thelengthoftimeaparticlestaysinsuspensionincreasesasthe

particlesizedecreases.Thecoarsest,heaviestparticles(gravel)aretransportedonlyashortdistance,whilewaterflowisatitsmaximum.Smaller,lighterparticles(sand)movebyrollingorbouncingalongthesurface,orstayinsuspensionovershortdistanceswhilethewatervelocity

isfairlyhigh.Becauseoftheirslowsettlingrate,fine

siltparticlesgenerallyremainforseveralhoursinsuspensioninthestormrunoffthatoriginallymovedthem.Thestillfinercolloidal

claysstayinsuspensionforverylongperiodsandcontributesignificantlytowaterturbidity.

Factors that Influence Erosion

Therearefourprincipalfactorsthatinfluencethepotentialforerosion:soils,surfacecover,topography,andclimate.Thesefactorsare

interrelatedintheireffectonerosionpotential.Variabilityinterrain,soils,andvegetationmakeserosioncontrol

uniquetoeachdevelopment.Erosionandresultingsedimentationgenerally

occurinMassachusettsonlywhenthesoilisdisturbed.Theseriousnessoftheproblemisafunctionofthetopographyandsizeoftheareadisturbed,thecharacteristicsofthesoils,theclimate,andthevegetativecover.

Asaruleofthumb:

$Themorefine-grainedmaterialthereisinasoil,thegreaterthe

amountofmaterialthatwillbepickedupbywaterflowingacrossits

surface;$Thesteepertheslope,thefasterthewaterwillmove,thusbeing

abletocarrymoresoil;and,

$Thelargertheunprotectedsurface,thelargerthepotentialfor

problems.


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10 Principles and Planning

SoilsThevulnerabilityofasoiltoerosionisknownasitserodibility.Key

factorsthatinfluenceerodibilityare:

$Soiltexture(proportionsofsand,silt,andclay)

$Organicmattercontent

$

Soilstructure(arrangementofsoilparticles)

$Soilpermeability(theeasebywhichwaterpassesthroughthesoil)

Soiltextureisdescribedbytheproportionsofsand,silt,andclayinthesoil.Highsandcontentgivesacoarsetexture,whichallowswaterto

infiltratereadily,reducingrunoff.Arelativelyhighinfiltrationratecoupledwithresistancetotransportbyrunoffresultsinalowerosionpotential.Soilscontaininghighproportionsofsiltandveryfinesandaremost

erodible.Clayparticlesandorganicmatterinthesoiltendtobindittogetherintoaggregates,therebyreducingerodibility.Whenclayerodes,however,theparticlessettleoutveryslowly.

Organicmatter,suchasplantmaterial,humus,ormanure,improves

soilstructure,increaseswater-holdingcapacity,and

mayincreasetheinfiltrationrate.Itreduceserodibilityand

theamountofrunoff.Soilstructureis

determinedbytheshapeand

arrangementofsoilparticle.Astable,sharp,granularstructureabsorbswater,readily,resistserosionby

surfaceflow,andpromotesplantgrowth.Claysoilsor


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compactedsoilshaveslowinfiltrationcapacitiesthatincreaserunoffrateandcreatesevereerosionproblems.

Soilpermeabilityreferstoasoilsabilitytotransmitairandwater.

Soilsthatareleastsubjecttoerosionfromrainfallandshallowsurfacerunoffarethosewithhighpermeabilityrates,suchaswell-gradedgravelsandgravel-sandmixtures.Loose,granularsoilsreducerunoffbyabsorbing

waterandbyprovidingafavorableenvironmentforplantgrowth.Wellgradedsoilsarethosewhichcontainawiderangeofparticlesizes.Well-drainedandwell-gradedgravelsandgravelsandmixtureswithlittleornosilthavelowerodibilitytosheetflow,butwasheasilyunderconcentrated

flow.Coarse,granularsoilsalsohavehighpermeabilitiesandasufficientlygoodinfiltrationcapacitytopreventordelayrunoff.

Surface Cover

Vegetativecoverisextremelyimportantincontrollingerosion.Itperformsthesefunctions:

$ Shieldsthesoilsurfacefrom

theimpactoffallingrain,

$ Holdssoilparticlesinplace,

$ Helpstomaintainthesoils

capacitytoabsorbwater,

$ Slowsthevelocityofrunoff.

Soilerosionandsedimentationcanbesignificantlyreducedbyschedulingconstructionactivitiestominimizetheareaofexposedsoiland

thetimeofexposure.Specialconsiderationshouldbegiventothemaintenanceofexistingvegetative

coveronareasofhigherosionpotentialsuchaserodiblesoils,steepslopes,drainageways,andbanksofstreams.

Vegetationslowsrunoffvelocity,

dispersesflow,andpromotesinfiltrationanddepositionof

sediment.Plantsremovewaterfromthesoil,increasingthecapacitytoabsorbwater.Plantrootshelpmaintainsoilstructure.

Thetypeandconditionofgroundcoverinfluencetherateandvolume

ofrunoff.Impervioussurfacesprotecttheareacovered,butpreventinfiltrationanddecreasethetimeofconcentrationforrunoff,therebyincreasinghighpeakflowandpotentialforstreamandchannelerosion.Coverssuchasmulches,paving,andstoneaggregatesalsoprotectsoils

fromerosion.


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Effects of UrbanizationBeforecolonialtimes,mostofMassachusettswasforested.The

forestsystemprovidedprotectionbyinterceptingrainfallinthetreecanopy,reducingthepossibilityoferosionandthedepositionof

sedimentinwaterways.Thetreesandtheforestdufflayerabsorbedlargeamountsofrunoff,releasingitslowlytothestreamsby

percolationthroughthesoil.Assettlementoccurredandthepopulationgrew,landwas

clearedforbuildings,fields,pasturesandroads.Lowspots,oftenwetlands,werefilled.Today,asareasareconvertedtourbanuses,thenaturalvegetationisremoved,landslopesaremodified,areasarepavedover.

Aftervegetatedterrainiscleared,theadditionalareaofcompactedandimpervioussurfaceschangesthehydrologiccharacteristics.Volumeofsurfacerunoffandtherateofflow

increases.Groundwaterrechargedecreases.Runoffthatwaspreviouslyslowlyreleasedtostreamsbyfilteringthroughthesoilnow

runsquicklyoffthesurfacedirectlyintothestreams.Thisincreasesvelocityandquantityofflowcausingstreambankerosionandgeneral

habitatdestruction.Sedimentfromerodedandunstablestreambanksandclearedareasisdepositeddownstream;fillingponds,streambedsandstormwaterfacilities.Summerbaseflowsarereduced.

Inadditiontotheincreaseinimpervioussurfaces,urbanizationcreatesasignificantamountofgroundsurfacemodification.Naturaldrainagepatternsaremodifiedandrunoffistransportedviaroadditches,stormsewers,drainageswales,andconstructedchannels.

Thesemodificationsincreasethevelocityoftherunoffwhichineffectdecreasesthetimethatittakesforrunofftotravelthroughthe


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watershed.Thisdecreasedtimecreateshigherpeakdischarges.Vegetativecoveronanundisturbedsiteprotectsthegroundsurface.

Removalofthatcoverincreasesthesitessusceptibilitytoerosion.

Disturbedlandmayhaveanerosionrate1,000timesgreaterthanthepre-constructionrate.Properplanninganduseofcontrolmeasurescanreducetheimpactofman-inducedacceleratederosion.

Themajorproblemassociatedwitherosiononaconstructionsiteisthemovementofsoiloffthesiteanditsimpactonwaterquality.MillionsoftonsofsedimentaregeneratedannuallybyconstructionactivitiesintheUnitedStates.Therateoferosiononaconstructionsitevarieswithsite

conditionsandsoiltypesbutistypically100to200tonsperacreandmaybeashighas500tonsperacre.

Undernaturalconditions,streamchannelswillnormallyhandle,atbankfull,capacitythepeakdischargefromastormthatcouldbeexpected

onceeverytwoyears.Theincreaseddischargecausedbyurbanizationwillcauseout-of-bankfloodingmorefrequently.Thestreamchannelbeginstowidenanddeepentoaccommodatetheincreasedflowandtochangegrade

tohandletheincreasedvelocity.Eventuallytheincreasedsedimenttransportcanleadtoproblemsdownstream.

Urbanizationcanbeasignificantcauseofpollutionproblemsduetosedimentloads,withbothshort-termandlong-termimpacts.Short-term

changesinwaterqualitycanrestrictrecreationalactivities,stressaquaticorganisms,anddamageshellfishbeds.Long-termaccumulationofpollutantsintoreceivingwaterscancreateparticularlydifficulttocorrect

problemssuchaseutrophication,pollutedgroundwater,andcontaminatedsediments.


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Erosion and Sediment Hazards Associated with

Site DevelopmentHazardsassociatedwithsitedevelopmentincludeincreasedwater

runoff,soilmovement,sedimentaccumulation,andhigherpeakflowscausedby:


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Analyzing the Project SiteMostsoilandwatermanagementproblemsencounteredduring

landusechangearecausedbyoneormoreofthefollowing:$SoilLimitations,

$SlopingLand,

$DrainageProblems

$

ExposedSoil.

Soil Characteristics and LimitationsSoilcharacteristicshaveamajorinfluenceonhowaproposed

developmentsitecanbestbeutilized.Characteristicssuchastexture,permeability,andstructureaffectasoilserodibility.Other

characteristicsthataffectthepotential,andthelimitations,ofasiteincludenaturaldrainage,depthtoseasonalwatertable,depthtobedrock,floodhazardpotential,naturalfertility,andengineering,physical,andchemicalproperties.

Significantdifferencesinsoilpropertiescanoccurwithinshortdistances.Somesoilsareseasonallywetorsubjecttoflooding.Someareshallowtobedrock.Somearetoounstabletobeusedasafoundation

forbuildingsorroads.Finer-texturedorwetsoilshaveseverelimitationsforuseasseptictankabsorptionfields.Asitewithahighwatertableispoorlysuitedtobasementsorundergroundinstallations.Depthtobedrockortoacementedpan(cementedorhardenedsubsurface

layers),largestones,slope,andthehazardofcutbankscavingaffectthestabilityofditchbanksandtheabilityofconstructionequipmenttoperformexcavationorgradingwork.Knowledgeofthesoilpropertiesisofgreatvalueindecidinghowtoutilizetheprojectsite.

DrainageDrainageistheremovalofexcesssurfaceandsubsurfacewater

fromthesoil.Howeasilyandeffectivelythesoilisdraineddependsonthedepthtobedrock,toacementedpan,ortootherlayersthataffecttherateofwatermovement;permeability;depthtowatertable(depthtostandingwaterifthesoilissubjecttoponding):slope;susceptibility

toflooding;subsidenceoforganiclayers;andpotentialfrostaction.


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Somesoilsaresowetthatitwouldbedifficulttousethemfordevelopment.TwoexamplesaretheScarborosoilseries(muckyfinesandyloam),foundonoutwashplainsandterraces;andtheWhitman

soilseries(finesandyloam)foundinsomeuplandareas.Poorly-drainedsoilssuchasRidgeburyandWalpolehaveseverelimitationsforhouses,smallcommercialbuildings,orlawns.Evenmoderately-well-drainedsoils

suchastheWoodbridge,Sudbury,orDeerfieldserieswouldpresentmoderatetoseverelimitationsforsomedevelopmentpurposes.

Depth to seasonal high water tableAreaswithahighwatertableshouldeitherbeavoidedorstepstaken

tocontrolthecondition.Ahighwatertablecancausemalfunctioning

septicsystems,dampbasements,andunevenfoundationsettlement.

Depth to bedrockIftherockissoftorfractured,excavationscanbemadewith

trenchingmachines,backhoes,orsmallrippers.Iftherockishardormassive,blastingorspecialequipmentgenerallyisneededforexcavation.

Flood hazard potentialFlooding,thetemporarycoveringofthesoilsurfacebyflowingwater,iscausedbyoverflowingstreams,byrunofffromadjacentslopes,orby

inflowfromhightides.

Ability to support vegetationTilth(physicalconditionofthesoilrelatedtoeaseoftillage,fitness

asaseedbed,andimpedancetoseedlingemergenceandrootpenetration)isimportanttothegerminationofseedsandtheinfiltrationofwaterintothesoil.Soilsthathavegoodtiltharegenerallygranularand


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porous.Fertilitytendstobelowforsoilsintheirnaturalstate.Mostsoilsin

theNortheastareacid.Theyrequireapplicationsoflimetoloweracidity

sufficientlyforlawnsandothervegetationtodowell.Therearesomeexceptions;forexamplesomeshrubspreferacidsoils.

Soil Survey ReportsSoilsurveyreportsofferdetailedinformationonthesoil

characteristics.Thesereportscontainsoilmaps,soildescriptions,andsoilinterpretationtables.Theyhavebeenpublishedformostareasof

Massachusetts.CopiesareavailableforreviewatthelocalConservationDistrictoffice.

Soilsurveysmapsareaerialphotographsonwhichsoilscientists

havedrawnboundariesofnaturalsoilbodies,identifyingeachasa

specificmapunit.Amapunitdelineationonasoilmaprepresentsanareadominatedbyonemajorkindofsoiloranareadominatedbyseveralkindsofsoil,onthebasisofsoilseriesandsoilphase.Mapunit

descriptionsandaccompanyingtablesprovidedetailedinformationoneach,aswellasinterpretationsontheirusefornumerouspurposes.

Examplesoftwotablesareshownintheaccompanyingfigures.Asoilseriesismadeupofsoilsthathavehorizons(soillayers)

similarinarrangementandcharacteristics.Soilsofoneseriescandifferintexture,underlyingmaterial,slope,stoniness,wetness,etc.Onthebasisofsuchdifferences,asoilseriesisdividedintosoilphases.The

smallestmapunitthatispracticaltoidentifyisthreetofiveacres.

Everymapunitgenerallyhassomesoilsthatbelongtoothertaxonomicclasses.Thesesoilsareknownasinclusions.Theinclusionmaybesimilartothedominantsoilandthereforemaynotaffecttheuse

ormanagementofthesoil.Ontheotherhand,theinclusionmaybecontrastingandthereforerequiredifferentmanagementandmayaffectthepotentialuseofthesoilmappingunit.Inclusionscouldaffectthesitespecificuseofanareabutmayhavelittleornoeffectonbroaderland

usedeterminations.Soilsurveyreportsareveryusefultoplanners,contractors,

engineers,andlocalofficials.Plannerscanevaluatetheeffectsof

specificlandusesinanarea.Contractorscanidentifypotentialsourcesofsandandgravel,topsoil,androadfill.Theycanusethesurveyto

determinetheareaswherehighwatertable,restrictivelayersorbedrockmayhinderexcavation.Engineersandlocalofficialsmayalso

usethesurveytoplanforwastedisposalandsitedevelopment.Thereportscontaindescriptionsforeachsoilseries,with

informationonthecompositionofeachlayerofthesoilprofile;toa

depthofatleast60inches.Therearetablesevaluatingthelimitationsforuseofeachsoilseries.Othertablescontainengineering,physical,andchemicalproperties.

Soilsurveyreportsshouldbesupplementedwithonsitesoil

investigationforaspecificlanduse.


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Status of Soil Survey Reports in Massachusetts, as of January 1996.

Berkshire County Published

Franklin County Report being updatedHampden and Hampshire Counties, Western Published

Hampshire County, Central Published

Hampden County, Central Published

Hampden and Hampshire Counties, Eastern Published

Worcester County, Northwestern Awaiting publication

Worcester County, Northeastern Published

Worcester County, Southern Awaiting publication

Middlesex County Awaiting publication

Essex County, Northern Published

Essex County, Southern Published

Norfolk and Suffolk Counties Published

Plymouth County Report being updated

Bristol County, Northern PublishedBristol County, Southern Published

Barnstable County Published

Dukes County Published

Nantucket County Published

SlopesRunoffvelocityincreasesasslopelengthandgradientincrease.As

thevelocityincreases,sodoesitscapacitytodetachandtransportsoilparticles.Ingeneral,theflatterandshorteraslope,theslowertherunoff

velocityandthegreatertheinfiltrationrateonthatslope.Removalofexistingvegetativecoverfromslopesincreasesthe

vulnerabilityoftheslopestoerosion.Vegetationretardsrunoffvelocityandrootsystemsholdsoilparticlesinplace.Vegetationmaintainsthesoilscapacitytoabsorb

precipitation.Soilsaremostvulnerableto

erosionwherehighlyerodiblesoilsandsteeporlongslopes

appearincombination,andwheresurfacesoilsarelowinfertilityandabilitytosupport

vegetation.


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Practices to Divert RunoffRunoffcanbedivertedfromslopesthatareexposedduring

developmentbyusingdiversionstointerceptrunoffandkeepitawayfrom

theslopeface.Adiversionextendsacrossaslope,usuallyacombinationofdikeandditch.Diversionscanbeusedatintervalsacrosstheslopefacetoreduceslopelength.Diversionsarealsousedtocollectrunofffromaconstructionsiteanddivertittoasedimentretentiontraporpond.

Diversionscanbebarechannels,vegetativelystabilizedchannels,orlinedchannels(paving,erosioncontrolfabric,etc.).Temporarydiversionsmustremaininplaceuntilslopeshavebeenpermanentlyrestabilized.

Diversionsconcentratethevolumeofsurfacerunoff.Asaresult,theyalsoincreaseitserosiveforce.Itisimportanttoplaninadvanceforthedisposalofrunoffcollectedbydiversions.Runoffmustbereleasedontoastabilizedareatoreduceitserosionpotential.Insomecasesthiscanbe

simplyachievedbygraduallyreducingthegradientofthediversionchannel.


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Slope DrainsIfrunoffcannotbesatisfactorilydisposedofbyconveyingacrossa

slope,itcanbedrainedoverthefaceoftheslopeitself.Slopedrainscanrundownthesurfaceoftheslopeasasectionaldowndrain,paved

chute,orapipeplacedbeneaththesurfaceoftheslope.On-surfacesectionaldowndrainsareusuallycorrugatedmetal,or

plasticpipe.Theseslopedrainsaretemporary.Forpermanentinstallations;pavedchuteswithasurfaceofconcreteorbituminous

material,orsubsurfacepipesareused.Compactthesoilcarefullyatthemouthoftheslopedrainand

anchoritadequately.Otherwise,undercuttingcanoccuratthelipoftheslopedrainandunderthedrain.

Attheslopedrainoutlet,energydissipatorsarefrequentlynecessary.Failuretoutilizeanenergydissipater,suchasrockriprap,

canresultinseriouserosionproblemsattheoutflowendoftheslopedrain.Anenergydissipaterbreaksuptheflowofwaterandreducesvelocitytoanon-erosivelevel.


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Retaining Walls, Slope ProtectionRetainingwallsmaybeusedtoreduceextremeslopegradients,

dividingaslopeintoaseriesofshorter,flattersegmentsandstructuralverticalwalls.Retainingwallscanbeusedinasituationwherethebuilder

istryingtokeepexistingmaturevegetation.Thecostofbuildingretainingwallsisoftenjustifiedbecauseofthemaintenancecoststhataresavedonareasthatwouldbedifficultorimpossibletostabilizeotherwise.

Slopepaving(e.g.asphaltorconcretepaving,rocklining)mayalsobe

usedtoprotectsteepslopesthatcannotbevegetated.Ifpossible,usepermeablematerials.


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Slope Stabilization MeasuresAnotherwaytostabilizeslopesistoreducetheirsteepness.The

selectionoftheappropriategradeforcutandfillslopesshouldbebasedonseveralconsiderations.Thestabilityofthesoil,itsdrainage

characteristics,anditserodibilityshouldbeconsideredfirst.Iftheslopegradientisflattened,theoveralllengthoftheslope

increases,andthisincreasestheamountofsurfaceareasubjecttoerosion.Itiseasier,however,toestablishvegetationonaflatterslope.

Slopesurfacescanberoughenedbyrunningwheeledconstructionequipmentacrosstheslopes,ortrackedequipmentupanddowntheslopeface.Thisreducesthevelocityofwaterflowingdowntheslopeandincreaseinfiltrationrates.Theroughsurfaceholdswater,seed,and

mulchbetterthanasmoothslope.Thegroovescreatedbytheconstructionequipmentshouldrunacrosstheslopehorizontally,and

notupanddowntheslope.Slopescanalsobescarified(loosenedwithaharrow)toproducedesiredsurfaceroughness.


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Vegetative MeasuresWhenstreambanksmust

bedisturbed,orwhereexistingvegetativecoverisinadequate,

grassorgrass-legumemixturesmaybeestablished.Vegetativerestabilizationshouldbedoneimmediatelyafterstreambank

gradinghasbeencompleted.Grassandlegumevegetationisrecommendedfortheprotectionofstreambanks.

Woodyvegetation(shrubs)maybeusedificedamageisa

potentialproblem.Assoonasplantingor

seedinghasbeencompleted,banksshouldbemulchedandthemulchsecurelyanchored.Strawwithaplastic-emulsiontackingagent,excelsiorblanket,anettingoverstraw,orsimilarmaterialsmaybeused.Inrecent

yearsmanufacturershavedevelopedmanynewproductsforsoilstabilization.

Itisimportanttocheckperiodicallyandrepairareaswherevegetationhasfailed.

Structural Measures

Streambankscanbeprotectedfromerosionbystructuralaswellasvegetativemeasures.Ifvegetationwillnotprovidesufficientprotection,bankscanbeprotectedwithrevetmentsanddeflectors.

Wheresharpbendsoccurorwherethereareconstrictionsinthestreamchannel(suchasculverts,bridges,orgradecontrolstructures),

structuraltreatmentmaybenecessary.Riprap,gabions,andconcretepavingareoftenusedtoprotectandreinforceastreambank.Deflectors,consistingofjettiesorpilingsthatangleoutwardfromthebankina

downstreamdirection,mayalsobeusedtokeeperosivecurrentsawayfromvulnerablebankareas.

Grade Control StructuresGradecontrolstructurescanbeusedtoreducethechannelgradient,therebyreducingthevelocityofflowin

achannel.Checkdams,weirs,anddropspillways,madeofavarietyofmaterials,bothtemporaryandpermanent,reducechannelgradeand

dissipatetheenergyofflowingwater.Thesestructuresconcentratethevolumeofwaterandincreasevelocity


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offlow,therefore,specialcaremustbetakentopreventundercuttingatthetoeofthestructureanderosionofthebanks.

Sediment Traps or BasinsThefirststepinpreventingsedimentfromenteringstreamsand

waterwaysistocontrolerosiononconstructionsites.Thesecondistotrap

sedimenttransportedbyrunoffbeforeitreachesstreamsandwaterwaysorleavestheconstructionsite.Runoffmustbedetainedforasufficientperiodoftimetoallowthesuspendedsoilparticlestosettle.

Vegetativefilterstripsbetweenstreamsanddevelopmentareascan

slowrunoffandfilteroutsediment.Sedimenttrapscanbeconstructedin

drainageways.Sandbags,strawbalebarriers,

andexcavatedsedimenttraps,placedatregular

intervalswithinadrainagechannel,areeasyandeconomicaltoconstruct.Sandbagbarriersedimenttrapsareconstructedofbagsfilled

withsandorcrushedrockandstackedinaninterlockingmannerdesignedtotrapsedimentandreducevelocityofflow.

Strawbalebarriersedimenttrapsare

constructedofbalesofhayorstrawstackedandstakedinplace.Tyingthebalestostakeswithwireprovidesadditionalstability.Soil

excavatedfromthedrainagechannelshouldbe

compactedalongtheupstreamfaceofthebarrier.Piping,orundercutting,canbereducedbysettingthebalesatleastsixinchesintothe

bottomofthedrainwayandcompactingexcavatedsoilalongtheupstreamside.

Sedimenttrapsrequirecleaningoutperiodically;andtheyshouldbecheckedafterheavyrainstorepairanydamageandremoveaccumulated

sediment.Streamsmayalsobeprotectedfromincreasedsedimentloadsby

trappingrunoffinsedimentbasinsbeforeitisreleasedintostream

channels.Inadditiontotrappingsediment,thesebasinsaredesignedtoreleaserunoffatnonerosiverates.Sedimentbasinsusuallyconsistofan

earthendam,aspillwaytocarrynormalwaterflow,andanemergencyspillwayforstormflows.Constructsedimentbasinsbeforeclearingand

gradingofthemainsitebegins.Theyaregenerallylocatedatornearthelowpointofthesite.Sedimentbasinoutletsmustbestabilized.

Surfacerunoff,andrunoffinterceptedbyerosioncontrolmeasures

suchasdiversions,shouldbeconveyedinerosion-resistantdrainagewaysandreleasedtostabilizedareas,stormsewers,orsedimentbasins.Thedrainagewaysshouldbedesignedtoinsurethatrunoffistransportedwithoutriskoferosionorflooding.


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Thedevelopmentshouldbeplannedtomaintainandutilizetheexistingdrainageways.Increasesinrunoffvolumeandvelocitybecauseofchangesinsoilandsurfaceconditionsduringandafterconstruction

mustbeanticipated.Wherethecapacityofthenaturalsitedrainagechannelsisexceeded,additionalcapacity,stabilizingvegetation,orstructuralmeasureswillbeneeded.

Bare ChannelsBarechannelsshouldbeusedwithcaution,andonlyinareaswhere

thechannelslopeisquiteflat.Inareaswherethesoilshavemoderateto

higherosionpotential,stabilizationtechniqueswillneedtobeapartofthedesign.

Grassed WaterwaysWaterwaysaredesignedtotransportexcesssurfacewaterfrom

diversionsornaturalconcentrationsofflowinastablechannel.Grassedwaterwaysarevegetativelystabilizedchannels.Jutenetting,papertwinefabric,excelsiorblankets,andvariousothermulchingtechniquesare

frequentlyusedtoprotectchannelsuntilvegetationbecomeswellestablished.Insomevegetativelylinedchannels,bankprotectionmayalsobenecessary.Riprapisacommonlyusedmaterial.

GRASSED WATERWAY WITH

NETTING


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Lined ChannelsLiningsarenecessaryin

drainagewayswhere:vegetationcannotbe

establishedbecauseflowisoflongdurationinthechannel,runoffvelocitiesorconcentrationsarehigh,

erodiblesoilsexistorslopesareverysteep.Concretepavingandripraparecommonlyusedchannel

linings.Ingeneral,vegetativestabilizationandtheuseof

permeablechannellinings,suchasriprap,arepreferredtotheuseofimpermeablelinings,suchasconcreteorgroutedriprap.

Inlet ProtectionThecapacityofthestorm

sewersystemcanbeseverelyimpairedbysedimentdeposits.Sedimentshouldbe

preventedfromenteringanenclosedstormsewerbytemporarysedimenttrapsandfiltersatsysteminlets.Filtersmadeofcrushedrock,sod,or

strawbalescanbeplacedatinletswheresedimenttrapscannotbeconstructed.Itisessentialtochecktrapsandfiltersregularlyandremoveaccumulatedsediment.

Enclosed DrainageThecapacityofvegetateddrainagechannelsmaybeexceededbythe

increasesinrunoffcausedbyearthchangingactivities.Asaresult,vegetativelylinedchannelsmayscouranderode.Ifstormsewerswillbeneeded,installthembeforemajorconstructionbegins.


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Ground Cover

Vegetative Stabilization TechniquesGrassandlegumesarethemost

commonlyusedplantmaterialsforstabilizingslopes.Vegetationisusuallyestablishedinoneofthree

ways.

Hydroseeding

Amixtureofseeds,fertilizer,andwaterissprayedontheslope.Amulchandamulchtackingagent

shouldalsobeapplied.Hydroseedingiseffectiveonlargeareas.

Standard seedingSeedisdrilledorbroadcast

eithermechanicallyorbyhand.A

cultipackerorsimilartoolisusedafterseedingtocompacttheseedbedandcovertheseed.Thepropertimingofseeding,mulching,and

wateringisimportantforareasseededinthismanner.

SoddingSodstripsarelaidontheslope

andinthiswayinstantcoveris

provided.Sodshouldbeplacedonapreparedbedandpeggedonsteepslopes.Waterandfertilizerareimportant.Thismethodiseffective

andisoftenusedonsteepslopesandwaterwaychannels.

Suitablesoil,goodseedbedpreparation,andadequatewater,

lime,andfertilizeraremustsforallthesemethods.Immediatelyafterroughgradingiscompleted,exposedslopesshould

betemporarilystabilized.Iffinalgradingwillbedelayed,temporaryseedingandmulchingmaybeusedforshortperiodofprotection.

Assoonasslopesarebroughttofinalgrade,permanentvegetationshouldbeplanted.

Maintenancewillconsistprimarilyofmowing,fertilizing,liming,and

watering.Itshouldbescheduledonaregularbasis.Reseedbareareasasnecessary.


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MulchesMulchisusuallyusedafter

permanentseeding,butmaybeusedbeforeseedingtoprotectexposed

areasforshortperiods.Mulchesprotectthesoilfromtheimpactoffallingrain,slowthevelocityofrunoff,andincreasethecapacityofthesoilto

absorbwater.Mulchesholdseedinplace,preservesoilmoisture,andinsulategerminatingseedsfromtheextremesofheatandcold.

Manytypesofmulchareavailable;suchasstraw,woodchips,andexcelsiormats.Mostmulchesmustbeanchored,usingplasticemulsionsor

jute,fiberglass,orplasticnetting.

Vegetative Buffer StripsSedimentcanbereducedbymaintaininganaturalvegetativebufferor

filterstripatthebaseofaslopeandbyplacingsodstripsatintervals

acrossthefaceoftheslope.Thesemeasureshelptoslowrunoffandtrapsediment.

Potential ProblemsSomeoftheproblemsthatarisewhenasiteisdevelopedarehigh

watertable,flood-proneareas,seepage,oradversesoilconditions.Ifsuch

problemareasarerecognizedearly,siteplanscanbedevelopedtoaccommodate,notaggravate,them.


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Flood PlainsIstheproposeddevelopmentlocatedinafloodplain?ASoilSurvey

reportcanbeusedtolocateareassubjecttofloodingbystreamoverflow.Forexample,soilssuchasthoseintheHadleyorPodunkseries

wouldbedescribedassubjecttoflooding.Themapsinsoilsurveyreportsshowthelocationofsuchsoils.

IfaFloodHazardAnalysishasbeenperformedforthetown,itmaybeusedtolocatefloodhazardareas.

Ifneitheroftheaboveareavailable,aroughidentificationoffloodhazardareasmaybeaccomplishedbyinterviewinglocalresidents,checkingtownrecords.Fieldchecksofvegetativecovertypes,soilmoisture,orverticaldistanceabovestreamlevelhelppointout

susceptibleareas.

Effect of Development on Surface RunoffDevelopmentusuallyresultsintheincreaseofhard-surfaced,

imperviousareas,whichcanincreasefloodingdownstream.Theseeffectsmaybereducedthrough:

Minimum lot sizesForexample,therunofffromasubdivisionofone-quarteracrelots

foratwo-yearfrequencystormcanbe50%greaterthanthatfromthesamesubdivisionwithone-acrelots.

Preservation of the natural drainage pattern

Developmentmaydisruptdrainagepathsthathavedevelopedoverhundredsofyears.Theexisting,naturaldrainagewaysusuallyhavesufficientcapacityfortherunofffromallexceptmajor,infrequentstorm

events;unlesstherehasbeensignificantchangeinthecoverconditionsupstream.

Stormwater Retarding StructuresOftenitisnotfeasibletopreserveenoughofthenaturaldrainage

andvegetativecovertopreventanincreaseinrunoff.Aproperly

designedretardingstructuretemporarilystoresrunofffromadevelopedareaandreleasesthewateroveraperiodoftime,ataratewithinthecapacityofthechanneldownstream


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Adverse Soil ConditionsLarge Rocks and Ledge

Iftheseareencountered,developmentcostsrisesignificantly.Planthedevelopmentaroundtheseconditionsandleaverocksandledgeundisturbedifpossible.

Settlement PotentialFillsplacedonsoftorganicsoilsorlocatedinwetareastendtosettle

unlesscareistakentoseethattheyareproperlyconstructed.Foundations

forlargerbuildingsareusuallydesignedbyasoilsorfoundationsengineer,butplansforhouses,parkinglots,drivewaysmaynothavebeendevelopedwithsufficientconcernforpossiblefoundationsettlement.

Water Table

Areaswithahighwatertableshouldeitherbeavoidedorstepstakentodrainorotherwisecontrolthecondition.Highwatertablecancause

malfunctioningsepticsystems,dampbasements,unevenfoundationsettlement.

SeepageSeepagemaybeencounteredatthebaseofahill(wheretheground

surfaceflattensout);oronaslope,wherearoadsidecutoranexcavationforafoundationismade.Houses,driveways,roads,parkinglots,etc.,

locatedinsuchareasusuallyrequiredrainagemeasures.

Cuts and FillsConstructedcutsandfillstendtochangesitecharacteristics

(drainage,soilmaterials,stability,etc.).Theearth-movinginvolvedraisesdevelopmentcosts.Acomparisonshouldbemadeofthecostofdoingsuchwork,andthesubsequentdrainagemeasuresrequiredvs.working

withthenaturalgroundcontourstominimizecutsandfills.Thecomparisonmayshowthelattertobemoreeconomical;aswellasmorepleasingtotheeye.

Stabilization Principles for Site DevelopmentReviewandconsiderallexistingconditionsintheinitialsiteselection

fortheproject.Selectasitethatissuitableratherthanforcetheterraintoconformtodevelopmentneeds.Ensurethatdevelopmentfeaturesfollow

naturalcontours.Steepslopes,areassubjecttoflooding,andhighlyerodiblesoilsseverelylimitasitesuse,whilelevel,well-drainedareasofferfewrestrictions.Controlseepageandhighwatertableconditions.Anymodificationofasitesdrainagefeaturesortopographyrequiresprotection

fromerosionandsedimentation.


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Keep Disturbed Areas Small

Carefulsiteselectionwillhelponthispoint.Thesite,orcorridor,shouldbeabletoaccommodatethedevelopmentwithaminimumofgrading.

Thedevelopmentplanshouldfititstopographic,soil,and

vegetativecharacteristicswithaminimumofclearingandgrading.Naturalcovershouldberetainedandprotectedwhereverpossible.Criticallyerodiblesoil,steepslopes,streambanks,anddrainagewaysshouldbeidentified.Thedevelopmentcanthenbeplannedtodisturb

thesevulnerableareasaslittleaspossible.Whereearthchangeandremovalofvegetationarenecessary,keep

theareaanddurationofexposuretoaminimum.Planthephasesof

developmentsothatonlyareaswhichareactivelybeingdevelopedare

exposed.Allotherareasshouldhaveagoodcoverofvegetationormulch.


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Stabilize and Protect Disturbed Areasas Soon as Possible

Twomethodsareavailableforstabilizingdisturbedareas:mechanical(orstructural)methodsandvegetativemethods.Insomecases,botharecombinedinordertoretarderosion.

Keep Stormwater Runoff Velocities LowTheremovalofexistingvegetativecoverduringdevelopmentandthe

resultingincreaseinimpermeablesurfaceareaafterdevelopmentwillincreaseboththevolumeandvelocityofrunoff.Theseincreasesmustbetakenintoaccountwhenprovidingforerosioncontrol.


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Protect Disturbed Areas from Stormwater RunoffBestmanagement

practicescanbeutilizedtopreventwaterfromentering

andrunningoverthedisturbedarea.Diversionsandothercontrolpracticesinterceptrunofffromhigher

watershedareas,storeordivertitawayfromvulnerableareas,anddirectittowardstabilizedoutlets.

Retain Sediment

within the Corridor or Site AreaSedimentcanberetainedbytwomethods:filteringrunoffasitflows

anddetainingsediment-ladenrunoffforaperiodoftimesothatthesoil

particlessettleout.Thebestwaytocontrolsediment,however,istopreventerosion.

Afterconstructioniscompleted,inspectionandmaintenancearevital

totheperformanceoferosionandsedimentationcontrolmeasures.Ifnotproperlymaintained,somepracticesmaycausemoredamagethantheyprevent.

Whenconsideringwhichcontrolmeasuretouse,alwaysevaluatethe

consequencesofameasurefailing.Failureofapracticemaybehazardous

ordamagingtobothpeopleandproperty.Forexample,alargesedimentbasinfailurecanhavedisastrousresults;lowpointsindikescanallowthemtooverflowandcausemajorgulliesafillslope.

Itisessentialtoinspectallpracticestodeterminethattheyareworkingproperlyandtoensurethatproblemsarecorrectedassoonastheydevelop.Providesomemeanstoseethatroutinechecksofoperating

erosionandsedimentationcontrolpracticesarecarriedoutafterconstructionisover.


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Data Collection and Preliminary Analysis

Thebasemapfortheerosioncontrolplanispreparedfromadetailedtopographicmap.AsoilsmapmaybeobtainedfromthelocalConservationDistrictoffice.Transferringsoilsurveyinformationtothetopographicmapishelpfulforsiteevaluation.Inspectthesitetoverify

thebasemapwithrespecttonaturaldrainagepatterns,drainageareas,generalsoilcharacteristics,andoff-sitefactors.

Thebasemapshouldreflectsuchcharacteristicsas:

$ Soiltypeandexistingcontours,

$ Naturaldrainagepatterns,

$ Unstablestreamreachesandfloodmarks,

$ Watershedareas,

$ Existingvegetation, Basemapshouldinclude:

$ Criticalareassuchassteepslopes,

erodingareas,rockout Scalecroppings,andseepagezones, Northarrow

$ Uniqueornoteworthylandscape BenchmarkPropertyboundariesvaluestoprotect,Lotlines

$ Adjacentlanduses;especially

areassensitivetosedimentationorflooding,Criticalorhighlyerodiblesoilsthatshouldbeleftundisturbed.

Usethebasemaptolocate:

$ Bufferzones,

$ Suitablestreamcrossingareas,

$ Accessroutesforconstructionandmaintenanceofsedimentation

controldevices,

$ Borrowandwastedisposalareas,and

$ Themostpracticalsitesforcontrolpractices.

Analysisofthetopography,soils,vegetation,andhydrologywillhelptheplannersanddesignerstorecognizethelimitationsofthesite,andidentifylocationssuitablefordevelopment.

Preparing the PlanTheerosionandsedimentationcontrolplanshouldseektoprotect

thesoilsurfacefromerosion,controltheamountandvelocityofrunoff,

andcapturesedimenton-siteduringeachphaseoftheconstructionproject:

Schedule activitiesCoordinateinstallationoferosionandsedimentcontrolpractices

withconstructionactivities.

Sedimentcontrolpracticesshouldprecedegradingactivities.


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Protect the soil surface

Limittheextentofdisturbance.Stabilizethesoilsurfaceimmediately.Oncethesurfacehasbeendisturbed,itisvulnerabletoerosionandshouldbeprotectedwithappropriatecover,suchasmulchorvegetation.

Control surface runoffDivertwaterfromundisturbedareastoavoiddisturbedareas.Break

uplongslopeswithtemporarydiversionstoreducethevelocityofrunoff.Divertsediment-ladenwatertosedimentimpoundments.Makealloutletsandchannelsstablefortheintendedflow.

Capture sediment on-siteDivertrunoffthattransportssedimenttoanadequatesediment-

trappingdevicetocapturesedimentonthesite.

Preparing the Plan - Step by StepRunoff-Erosion AnalysisLandscape

Evaluateproposedchangesinthelandscapetodeterminetheireffectonrunoffanderosion.Makeanoteofallphysicalbarrierstosurfacerunoff,suchasroads,buildings,andberms.Checkslopegradesandlengthsfor

potentialerosionproblems.Designateintendedcollectionpointsforconcentratedflowandspecifycontrolstodissipateenergyorstabilizethesurface.Designateareastobeprotectedorusedasbufferzonesinthisphase.

Runoff yieldEvaluatesurfacerunofffortheentirecontributingdrainagearea,both

on-siteandoff-site.Delineatesmallsubwatershedson-siteandestimatepeakrunoffratesandvolumesatselectedcollectionpoints.Baserunoffdeterminationsonsiteconditionsduringandafterdevelopment,not

preconstructionconditions.

Sediment yield

Estimatesedimentyieldbysubwatersheds.Thisaidsinidentifyingpreferredlocationsforsedimenttrapsandbarriersandcanbeusedtoestimatetheexpectedcleanoutfrequency.Anareathatissubjecttoexcessiveerosionmayneedextrastoragecapacityintrapsoradditional

precautionsduringconstruction.

Sediment ControlErosioncontrolpracticesreducetheamountofsedimentgenerated,

buttheydonoteliminatetheneedforsedimentcontroldevicessuchasbarriersandtraps.Sedimentcontrolpracticesoperatebyreducingflowvelocityandcreatingshallowpoolsthatreducethecarryingcapacityof

runoff.Thussedimentationoccurson-siteratherthanoff-site.Sedimentisgenerallynotcontrolledbyfiltering,butbydeposition.Thedesignershouldlocatealltrapsandbarriersrecognizingthattheyrepresent

depositionpointswhereaccessformaintenancewillbenecessary.


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Sediment basins and traps

Selectsitesandinstallsedimentbasinsandtrapsbeforeotherconstructionactivitiesare

started.Also,considerlocationsfordiversions,openchannels,andstormdrainsatthistimesothatallsediment-ladenrunoffcanbe

directedtoanimpoundmentstructurebeforeleavingtheconstructionsite.

Divertsediment-freewater

awayfromsedimentbasinsandreleaseitthroughstableoutlets.

Thisreducesconstructioncostsandimprovesbasinefficiency.

Theplanshouldshowaccesspointsforcleanoutofalltrapsandbasinsandindicatesediment

disposalareas.Maintenanceofstoragecapacityisessentialthroughouttheconstructionperiod.

Sediment fences

Sedimentfencesprovide

effectivecontrolofsedimentcarriedinsheetflow.Theyareparticularlyusefulwherethereis

limitedspacetoworksuchasnearpropertylines,amongtrees,ornearsidewalksorstreets.Sedimentfencesshouldneverbe

usedacrossstreams,ditches,channels,orgullies. Asedimentfenceoperatesbyreducingflowvelocityandcausinga

shallowpooltoform.Iffilteringactionisrequired,thedesignershould

assumethatthebarrierwillclograpidlysothatallrunoffmustberetainedbehindthefenceorreleasedthroughadesignatedoutlet.Anyoutletpoints

mustbereinforcedandstabilizedandshouldbedesignatedintheplan.Placesedimentfencesonrelativelyflatgroundwithsufficientareafor

apooltodevelopwithoutputtingunnecessarystrainonthefence.Ifaleveareaisnotavailableatthefencelocation,excavateatrenchdirectlyupslopefromthefence.

Showsedimentfencesontheplanandindicatedepositionareasandneededoverfloworbypassoutletpoints.Alsoshowaccessroutesformaintenance.


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Inlet protection

Inletprotectiondevicesforstormsewers,conduits,slopedrains,orotherstructuresmakeeffective,low-costdepositionareasfortrappingandholdingsediment.Ashallowexcavationinconjunctionwithasediment

barriercanbeeffectiveatmanylocations.Showwherethesemeasureswillbelocated,whattypeofdevicewillbeused,andhowthesedeviceswillbeconstructedandmaintained.

Protection of Disturbed AreasOnceanareaisdisturbed,itissubjecttoacceleratederosion.Inthe

plan,showhowerosionwillbecontrolledonthesedisturbedareas.

Erosioncontrolcanbeachievedby: Limitingthesizeofclearingandtimeofexposurebyproper

scheduling,

Reducingtheamountofrunoffoverthedisturbedsurface,

Limitinggradesandlengthsofslopes,and Reestablishingprotectivecoverimmediatelyafterland-disturbing

activitiesarecompletedorwhenconstructionactivitiesaredelayedfor30

ormoreworkingdays.

Cut-and-fill slopesSteepcutorfillslopesareparticularlyvulnerabletoerosion.Protect

byinstallingtemporaryorpermanentdiversionsjustabovetheproposed

slopebeforeitisdisturbed.Provideastablechannel,flume,orslopedrain,whereitisnecessarytocarrywaterdownaslope.Flowchannelsmaybeeithervegetated,linedwithstone,orpaved,oracombination-depending

onslopeandsoilconditions.Shortenlongslopesbyinstallingtemporarydiversionsacrossthe

slopetoreduceflowvelocityanderosionpotential.Installpermanentdiversionswithslopedrainsandprotectedoutletsonlongsteepslopes

(over20%)astheslopesareconstructed.Finishfinalslopegradeswithoutdelayandapplysurfacestabilization

measuresassoonaspossible.Roughenslopesurfacestoimprovethesuccessofvegetativestabilization.Considerboththestabilization

measuresandhowtheywillbemaintainedbeforeplanningthesteepnessofthefinishslope.Forexample,ifthefinishedslopeistohavegrasscoverthatwillbemowed,itshouldbeconstructedonagradeof3:1orflatter.

Surface coversRiprap,gravel,strawandothercovermaterialscanprovideimmediate

surfaceprotectiontodisturbedsoilareas.Riprapisespeciallyusefulwhereconcentratedrunoffoccursoversteepslopes.Riprapshouldbeinstalledonagravelorfilterfabricbed.

Construction trafficConstructionroads,parkingareas,andconstructionaccessroutes

needtobecarefullyplanned.Ensurethattrafficpatternsfollowsitecontoursandlimitthelengthofroutesupsteeperslopes.Generally,roadgradesshouldnotexceed12%.


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Controllingsurfacerunoffisnecessarytopreventseriousroadsideerosion.Propergradingoftheroadsurface,stablechanneldesign,anduseofwaterbars,otherdiversions,andculvertshelppreventerosive

flows.Wherewatertablesarehigh,subsurfacedrainagemaybeneededto

stabilizethesubgrade.Stormdrainsshouldbeconsideredforwater

disposalwherechannelgradeexceeds5%.Plansshouldshowallstabilizationmeasuresneededtocontrolsurfacerunofffromallroads.

Borrow areas and disposal areasClearonlyasneeded,andprotectfromsurfacerunoff.Maintain

bermsasfillslopesareconstructedtoreduceslopelengthandcontrolrunoff.Slopeallareastoprovidepositivedrainage,andstabilizebaresoil

surfaceswithpermanentvegetationormulchassoonasfinalgradesareprepared.Directallrunoffthatcontainssedimenttoasediment-trapping

device.Inlargeborrowanddisposalsites,shapeanddeepenthelowerendtoformanin-placesedimenttrap,ifsiteconditionswarrantit.

Utilities

Usethespoilfromutilitytrenchexcavationstodivertflowfromupslopeareas(butusecareinspoilplacementtoavoidblockingnaturalsurfaceoutlets).Diversionsandwaterbarscanreduceerosionwhenproperlyspacedacrossutilityrights-of-way.

Whenutilitiesarelocatednearastream,maintainanundisturbedbufferzonewhereverpossible.Ifsitedewateringisnecessary,pumpordivertmuddywatertosedimenttrapsorsumppitsbeforedischargingit

tothestream.Ifstreamsmustbecrossed,makesureallnecessary

materialsandequipmentareon-sitebeforeconstructionbegins,andcompleteworkquickly.Finishalldisturbedsurfacestodesigngradeandimmediatelystabilizethemwithpermanentvegetationorothersuitable

means.Whereutilitiescrossthestream,specifymeasurestopreventsedimentation.

Perimeter protectionConsiderdiversiondikesforperimeterprotectionforallproposed

developmentsandinstallthemwhereappropriatebeforeclearingthe

site.Exercisecarenottocreatefloodingorerosionbyblockingthenaturaldrainagepattern.Besuretoprovideanadequateoutlet.

Dust controlExposedsoilsurfacesthatarenearlylevelhavelittlepotentialfor

runofferosionbutmaybesubjecttoseverewinderosion.Keepingthedisturbedsurfacemoistduringwindyperiodsisaneffectivecontrol

measure,especiallyforconstructionhaulroads.

Preserving vegetation

Preserveexistingvegetationonthesiteaslongaspossibleasacost-effectivewaytopreventon-siteerosionandoff-sitesedimentation.


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Runoff ConveyanceThesafeconveyanceofrunoffwaterfromaconstructionsiteis

achievedby:utilizingandsupplementingexistingstablewatercourses,designingandconstructingstableopenchannels,orinstallingstormdrainswithstableoutlets.Theplanshouldindicatelocationsanddesignsforthesefacilities.Completeandstabilizeoutletsforchannels,diversions,slopedrains,orotherstructuresbeforeinstallingtheconveyancemeasure.

ContactthelocalConservationCommissionregardinganystreamcrossingorotherworkconductedinawetlandresourcearea.TheMassachusettsWetlandProtectionActrequiresthattheproponentfilea

RequestforDeterminationofApplicabilityorNoticeofIntent.

Existing watercourses

Whenusingexistingwatercourses,eithershowthatflowvelocitiesareacceptableforincreasedrunoffconditionsorindicatehownecessarystabilizationwillbeachieved.

Excavated channelsWhenchannelsaretobeexcavated,thedesignshouldbepreparedby

aprofessionalengineer.Includecalculationsintheplandocumentation.Wide,shallowchannelswithestablishedgrassliningsareusually

stableonslopesupto5%.Thesechannelsmustbeprotectedwithtemporarylinersuntilgrassisestablished.Ifchannelgradientsaretoo

steeptousevegetation,ripraporconcreteliningsmayberequired.Insomeinstancesgradestabilizationstructuresmaybeneeded.

Storm drainsWherethesiteplancallsforasystemofstormdrains,thedrainsmay

beusedeffectivelyintheerosionandsedimentationcontrolplan.Build

junctionboxesorinletsearlyintheconstructionsequence,andgradetheadjacentareatodraintowardtheinlet.Installaninletprotectiondeviceatallopenpipeinletsandexcavateashallowbasinintheapproachtotheinletforsedimentstorage.

Thestormdrainflowfromtheprotectedinletsmaybedivertedtoasedimentbasinforadditionalsedimentcontrol.Restrictthedrainageareaforinletstolessthanoneacre.Inspectinletprotectiondevicesfrequentlyforneededmaintenance.

Stream ProtectionStreambanks,streambeds,andadjoiningareasaresusceptibleto

severeerosionifnotprotected.Includesufficientdetailtoshowthat

streamsarestablefortheincreasedvelocitiesexpectedfromthedevelopmentactivity.Ataminimum,allstreamsshouldbestableforflowsfromthepeakrunofffromthe10-yearstorm.

ContactthelocalConservationCommissionregardinganystream

crossingorotherworkconductedinawetlandresourcearea.TheMassachusettsWetlandProtectionActrequiresthattheproponentfileaRequestforDeterminationofApplicabilityorNoticeofIntent.


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Whenstabilityanalysisshowsthatthestreamrequiresprotection,vegetationisusuallythepreferredapproachbecauseitmaintainsthestreamnearesttoitsnaturalstate.Whenflowvelocitiesapproach4-6

feetpersecond,oriffrequentperiodsofbankfulflowsareexpected;structuralmeasuressuchasriprapliningorgradestabilizationstructuresareusuallynecessary.Intheplan,showwherestream

protectionisneededandhowitwillbeaccomplished.

Runoff into stream

Onlysediment-freerunoffmaybedischargedfromconstructionsitesdirectlyintostreams.Ensurethatallotherflowsenterfromdesiltingpoolsformedbysedimenttrapsorbarriers.

Velocity controlKeepthevelocityofflowdischargedintoastreamwithin

acceptablelimitsforsiteconditions.Controlvelocitybyinstallingan

appropriateoutletstructure.

Buffer zone

Areasadjoiningstreamsshouldbeleftundisturbedasbuffers.Existingvegetation,ifdenseandvigorous,willreduceflowvelocitiesandtrapsedimentfromsheetflow.However,theprincipalbenefitof

leavingnaturalbufferzonesalongstreamsisthattheypreventexcessiveerosioninthesesensitiveareas.Maintainingstreamcanopiesalsoprotectsfishandwildlifehabitats;providesshade,windbreaks,andnoisebarriers,protectsthebankfromout-of-bankfloodflows;and

generallypreservesnaturalsiteaesthetics.Indicatestreambufferzonesinplansthatinvolvenaturalstreams.

Thewidthisdeterminedbysiteconditionsbutgenerallyshouldnotbe

lessthan25feetoneachsideofthestream.Ifnaturalbuffersarenotavailable,provideartificialbuffers.


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Off-site stream protection

Increasedrateandvolumeofrunofffromdevelopmentactivitiesmaycauseseriouserosionatpointssomedistancedownstream.Thedevelopershouldworkwithdownstreampropertyownerstostabilizesensitive

downstreamchannelareas.

Stream crossing

Minimizethenumberofstreamcrossings.Constructcrossingsduringdryperiods.Ifnecessary,divertwaterduringconstruction.Theplanshouldshowthetypeofcrossingtobeusedandtheassociatedcontrolmeasurestominimizeerosionfromsurfacerunoffsuchasdiversions,

outletstructures,riprapstabilization,etc.

Construction SchedulingAppropriatesequencingofconstructionactivitiesisaneffective

meansforcontrollingerosionandsedimentation.Usetheconstructionscheduleofthegeneralcontractaspartoftheerosionandsedimentationcontrolplan.Installtheprimaryerosionandsedimentationcontrolpracticesforthesite,i.e.sedimentbasinsandtraps,andawater

conveyancesystembeforeundertakingmajorland-disturbingactivities.Scheduleworkwithaneyetothecalendar,tominimizeimpactsduetoseasonalchanges.

Installsedimentbasinsandprimarysedimentationcontrolpracticesasthefirststructuralmeasures.Nextinstalltheoverallwaterdisposaloutletsystemforthesite.

Stabilizeallconstructionaccessroutes,includingconstructionentrancesandexits,andtheroaddrainagesystem,astheroadsareconstructed.Installstormdrainsearlyintheconstructionsequenceandincludetheminthesedimentationcontrolplan.Installinletprotectiondevicesforefficientsedimentcontrolaroundtheinlets.Thisallowsearly

Construction Scheduling - EPA Baseline General Permit Requirements for

Site Stabilization:

Exceptasprovidedintheparagraphsbelow,stabilizationmeasuresshallbeinitiatedassoonaspracticableinportionsofthesitewhereconstructionactivities

havetemporarilyorpermanentlyceased,butinnocasemorethan14daysaftertheconstructionactivityinthatportionofthesitehastemporarilyorpermanentlyceased.

(a)Wheretheinitiationofstabilizationmeasuresbythe14thdayafter

constructionactivitytemporaryorpermanentlyceaseisprecludedbysnowcover,stabilizationmeasuresshallbeinitiatedassoonaspracticable.

(b)Whereconstructionactivitywillresumeonaportionofthesitewithin21daysfromwhenactivitiesceased(e.g.thetotaltimeperiodthatconstruction

activityistemporarilyceasedislessthan21days),thenstabilizationmeasuresdonothavetobeinitiatedonthatportionofsitebythe14thdayafterconstructionactivitytemporarilyceased


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useoftheinletsandthedrainsystem.Installdiversionsaboveareastobedisturbedand,whereneeded,

alongboundariesofareastobegradedbeforegradingtakesplace.

Afterallprincipalerosionandsedimentationcontrolmeasuresareinplace,performthelandclearingandroughgrading.Clearareasonlyasneededandcompletefinalgradingandsurfacestabilizationassoonas

possible.Minimizethetimeofexposureandselecttemporarygroundcoveraccordingtothelocationandseason.Temporarysurfacesshouldbestabilizedassoonasactivegradingissuspended,regardlessofthetimeofyear.Disturbedareasshouldberevegetatedearlyenoughintheautumn

thatgoodcoverisestablishedbeforecoldweathercomes.

Inspection and MaintenanceIntheerosionandsedimentationcontrolplan,indicatewhois

responsibleformaintenanceandwhenitwillbeprovided.Themaintenancescheduleshouldbebasedonsiteconditions,designsafeguards,constructionsequenceandanticipatedweatherconditions.

Specifytheamountofallowablesedimentaccumulation,designcross-section,and,requiredfreeboardforeachpracticeandwhatwillbedonewiththesedimentremoved.Theplansshouldalsostatewhentemporarypracticeswillberemovedandhowtheseareasandwastedisposalareas

willbestabilized.

Inspection ProgramEssentialpartsofaninspectionprograminclude:

Inspectionduringorimmediatelyfollowinginitialinstallationof sedimentcontrols. Inspectionfollowingsevererainstormstocheckfordamageto

controls. Inspectionpriortoseedingdeadlines,particularlyinthefall. Finalinspectionofprojectsnearingcompletiontoensurethat temporarycontrolshavebeenremoved,stabilizationiscomplete,

drainagewaysareinpropercondition,andthatthefinalcontours agreewiththeproposedcontoursontheapprovedplan. Inaddition,interiminspectionsshouldbemadeasmanpowerand workloadpermit,givingparticularattentiontothemaintenanceof

installedcontrols. Allinspectionsshouldbedocumentedbyawrittenreportorlog. Thesereportsshouldcontainthedateandtimeofinspections,dates

whenland-disturbingactivitiesbegin,commentsconcerning complianceornoncomplianceandnotesonanyverbal communicationsconcerningtheproject.


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Before ConstructionAnon-sitepreconstructionmeetinginvolvingtheowner,contractor,

anderosioncontrolpersonnelisrecommended.Thisallowsallpartiestomeet,reviewtheplansandconstructionschedule,andagreeonresponsibilityanddegreeofcontrolexpected.Discussmaintenancerequirements,phasingofoperations,andplanrevisions.Thepreconstructionmeetingisespeciallyimportantforlarge,complexjobsor

whenthecontractorand/ordeveloperhashadlittleexperienceinthistypeofwork.

During ConstructionThedevelopermaybeheldresponsibleforoff-sitesedimentdamage

resultingfromconstructionactivitieseventhoughanapprovedplanhas

beenproperlyinstalledandmaintained.Therefore,inspectthepropertyboundaryfrequentlyforevidenceofsedimentation.

Itmaybenecessarytomodifytheerosionandsedimentcontrolplanduringconstructiontoaccountforunanticipatedeventsorconstruction

changes.

During Construction

Inadditiontotheinspectionandmaintenancereports,the operatorshouldkeeprecordsoftheconstructionactivityonthe site,including:

Dateswhenmajorgradingactivitiesoccurinaparticulararea. Dateswhenconstructionactivitiesceaseinaparticulararea, temporarilyorpermanently.

Dateswhenaparticularareaisstabilized,temporarilyor permanently.

After Construction

Itemstoconsiderafterconstructioniscompletedincludepermanentstabilizationonceactivitieshaveceased,removaloftemporarystructural

measures,finalinspection,andmaintenanceofpermanentstructures.


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References

Lobdell,Raymond,AGuidetoDevelopingandRe-DevelopingShorelandPropertyinNewHampshire,NorthCountryResourceConservationand

DevelopmentArea,Inc.,Meredith,NH,1994.

MassachusettsDepartmentofEnvironmentalProtection,OfficeofWatershedManagement,NonpointSourceProgram,Massachusetts

NonpointSourceManagementManual,Boston,Massachusetts,June,1993.

MinnesotaPollutionControlAgency,DivisionofWaterQuality,ProtectingWaterQualityinUrbanAreas,BestManagementPracticesforMinnesota,

________,MN,October,1989.

Minnick,E.L.,andH.T.Marshall,StormwaterManageementandErosionControlforUrbanandDevelopingAreasinNewHampshire,RockinghamCountyConservationDistrict,August1992.

NorthCarolinaSedimentControlCommission,ErosionandSediment

ControlPlanningandDesignManual,Raleigh,NC,September,1988.

Schueler,ThomasR.,Controlling,UrbanRunoff:APracticalManualforPlanningandDesigningUrbanBMPs,MetropolitanWashingtonCouncilof

Governments,Washington,DC,July,1987.

SouthernNewEnglandChapter,SoilConservationSocietyofAmerica,

RecommendationsforErosionandSedimentControlDuringLandUseChange,January,1978.

Tourbier,J.,andR.Westmacott,WaterResourcesCenter,Universityof

Deleware,WaterResourcesProtectionMeasuresinLandDevelopment-AHandbook,Newark,Del.,April,1974.

U.S.EnvironmentalProtectionAgency,GuidanceSpecifyingManagementMeasuresForSourcesOfNonpointPollutionInCoastalWaters,EPA-840-B92-002,Washington,DC,January,1993.

WashingtonStateDepartmentofEcology,StormwaterManagementManualforthePugetSoundBasin,Olympia,WA,February,1992.


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54Best Management Practices

Best Management Practice SelectionBest

ManagementPractices

(BMP)

Selection

BMPSelection

SiteWork

Clearingand

Grading

Excavations,Stockpiles&DebrisDisposal

Rill& GullyErosion

SedimentControl

StormRunoff

StreambankProtectionandStabilization

StreamCrossing

Building

Construction,UtilitiesInstallations

SpecialSiteProblems

FinalSiteStabilization

Onanyconstructionsitetheobjectiveinerosionandsedimentcontrol

istopreventoff-sitesedimentationdamage.Fourbasicmethodsareusedtocontrolerosiononconstructionsites:planning,soilstabilization,runoffcontrolandsedimentcontrol.Carefulsiteanalysis,planningandschedulingcanreducetheneedtoutilizestabilizationandcontrolpractices,and,thereby,reducethecostofimplementingthesemeasures.

Identify Control ProblemControllingerosionshouldbethefirstlineofdefense.Controlling

erosionisveryeffectiveforsmalldisturbedareassuchassinglelotsorsmallareasofadevelopmentthatdonotdraintoasediment-trapping

facility.Wheresoilpropertiesandtopographyofthesitemakethedesign

ofsedimenttrappingfacilitiesimpractical,runoffcontrolandsoilstabilizationshouldbeused.

Sedimenttrappingfacilitiesshouldbeusedonlargedevelopments

wheremassgradingisplanned,whereitisimpossibleorimpracticaltocontrolerosion,andwheresedimentparticlesarerelativelylarge.Acombinationoferosioncontrolandsedimentationcontrolmeasuresisusuallytheleastexpensivewaytoaccomplisherosionandsediment

control.

Identify Problem AreasAreaswhereerosionistobecontrolledusuallyinvolveslopes,graded

areasordrainageways.Slopesincludegradedrights-of-way,stockpile

areas,andallcutorfillslopes.Gradedareasincludeallstrippedareasotherthanslopes.Drainagewaysareareaswhereconcentrationsofwaterflownaturallyorartificially.Problemareasthatneedsedimentcontrolcanbeeitherlargeorsmall.

Identify Required StrategySelectthestrategytosolvetheproblem.Strategiescanutilizean

individualpracticeoracombinationofpractices.Forexample,ifthereisacutslopetobeprotectedfromerosion,thestrategiesmaybetoprotectthegroundsurface,divertwaterfromtheslopeorshortenit.Anycombinationoftheabovecanbeused.Ifnorainfallexceptthatwhichfallsontheslope

hasthepotentialtocauseerosion,andiftheslopeisrelativelyshort,protectingthesoilsurfacemaybeallthatisrequiredtosolvetheproblem.

Select Specific Control MeasuresThetablesonthefollowingpagesareguidesforselectingerosionand

sedimentcontrolpractices.Thismaterialcanbeusedbyeitherdesignersanddevelopersorbyplanreviewagencies.

Thepracticeschosenforasitewilloftenvaryfromoneindividualtoanother,dependingonindividualjudgementandpreference,past


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experiencewithaconservationpractice,andthepracticessuitabilityforaparticularsite.Personsreviewinganerosionandsedimentationcontrolplanshouldnotexpecttofindonesetofpredeterminedpracticesused.

Thereviewercan,however,refertothesetables:(a)asanaidinrecognizingpotentialproblemareasthatmayexistatasite,and(b)forguidancetoseeifthedeveloperanddesignerhaveaddressedthe

potentialproblems.

SITE WORK:

On-site Roads, Controlling Road Runoff

ITEM RECOMMENDED PRACTICES

SitePreparation PreservingNaturalVegetationConstructionEntrance

ConstructionRoadStabilization

FilterBerm

SurfaceStabilization TemporarySeedingMulching

Riprap

RunoffControl TemporaryDiversionsWaterBars

SumpPit

RunoffConveyance GrassedWaterway(Slopesupto5%)LinedWaterwayTemporarySlopeDrainPavedFlume

VegetatedSwaleInletProtection

OutletProtectionandStabilization

Other DustControl

(Note:Thestructuralpracticeslistedabovearesuitableforslopesofupto12%,

exceptasnoted.Steeperslopesusuallyneedspecialconsideration.)


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56

Clearing and Grading

ITEM

Best Management Practices

RECOMMENDED PRACTICES

SitePreparation

SurfaceStabilization

RunoffControl

OutletProtection

RunoffConveyance

SedimentTrapsandBarriers

Other

PreservingNaturalVegetation

ConstructionEntrance

LandGrading

Surfaceroughening

TerraceTopsoilingTemporarySeeding

PermanentSeedingMulching

Riprap

TemporaryDiversion

PermanentDiversionTerraceWaterBar

SumpPit


LevelSpreader

SeeStormRunoffsheet

SeeSedimentControlsheet

DustControl

Excavations, Stockpiles, & Debris Disposal


SurfaceStabilization SurfacerougheningTopsoiling

TemporarySeedingPermanentSeedingTreesandShrubPlanting

Mulching

RunoffControl TemporaryDiversion

SedimentTrapsandBarriers SedimentTrap

SedimentFence

Other DustControl


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Storm RunoffITEM RECOMMENDED PRACTICES

Drainage area less than 20 acresRunoffControl TemporaryDiversion

PermanentDiversion

WaterBar

RunoffConveyance GrassedWaterway(Slopesupto5%)VegetatedSwaleLinedwaterway

Riprap-linedChannelTemporarySlopeDrain

PavedFlume

InletProtection

OutletProtection

Drainage area more than 20 acres

LevelSpreader (Drainageupto5acres)


Sameasabove,exceptinaddition,thedesignerwouldnormallyperform

hydrologicandhydrauliccalculationsshowingthatrunoff,duringandafterconstructionoftheproject,wouldcomplywithpermittingagencyrequirements.

Streambank Protection and Stabilization


Designvelocity VegetativeMethodslessthan6feetpersecond SoilBioengineeringMethods

StructuralMethods

Designvelocity SoilBioengineeringMethodsmorethan6feetpersecond StructuralMethods

(Note:ContactthelocalConservationCommissionregardinganyworkconductedinwhatmaybeawetlandresourcearea.TheMassachusettsWetlandProtection

ActrequiresthattheproponentfileaRequestforDeterminationofApplicabilityorNoticeofIntent.)


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Stream Crossings


TemporaryTemporaryTemporaryTemporaryTemporary

Tomoveequipment StreamCrossing,Temporary

SurfaceStabilization

PermanentPermanentPermanentPermanentPermanent

TemporarySeeding

Mulching

Riprap

Vehiculartraffic,TomoveEquipment PermanentStreamCrossing;e.g.BridgeorCulvert

SurfaceStabilization PermanentSeedingMulching

Riprap

(Note:ContactthelocalConservationCommissionregardinganyworkconducted

inwhatmaybeawetlandresourcearea.TheMassachusettsWetlandProtectionActrequiresthattheproponentfileaRequestforDeterminationofApplicability

orNoticeofIntent.)

Building Construction, Utilities Installations


SurfaceStabilization SurfaceRougheningTopsoilingTemporarySeeding

PermanentSeedingMulching

TreeandShrubPlanting

RunoffControl TemporaryDiversionWaterBar

SumpPit

SedimentControl SedimentTrapSedimentFence

FilterStrip

Other ConstructionRoadStabilizationDustControl


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Special Site Problems


Seepageareasorhighwatertable SubsurfaceDrainageSumpPit

Unstabletemporarychannels CheckDamRiprap-linedChannel

Unstablepermanentchannels Riprap-linedChannelLinedWaterway

GradeStabilizationStructure

Blowingdustorsand DustControlSandFence

Dunereinforcementandstabilization SandDuneandSandblowStabilization

SandFence

(Note:ContactthelocalConservationCommissionregardinganyworkconducted

inwhatmaybeawetlandresourcearea.TheMassachusettsWetlandProtectionActrequiresthattheproponentfileaRequestforDeterminationofApplicability

orNoticeofIntent.)

Final Site StabilizationITEM RECOMMENDED PRACTICES

SurfaceStabilization SurfacerougheningTerraceTopsoiling

PermanentSeedingSoddingTreesandShrubPlanting

Mulching

Riprap

RunoffControl PermanentDiversion

RunoffConveyance GrassedWaterwayVegetatedSwaleLinedWaterway

Riprap-linedChannel

PavedFlume

OutletProtection

InletProtection

LevelSpreader


SodDropInletProtection,or

permanentpaving


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References

ConnecticutCouncilonSoilandWaterConservation,ConnecticutGuidelines for Soil Erosion and Sediment Control,Hartford,CT,January,1985.

New York Guidelines for Urban Erosion and Sediment Control,March1988.

NorthCarolinaSedimentControlCommission,Erosion and SedimentControl Planning and Design Manual,Raleigh,NC,September,1988.

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