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1. 540R92073 Technical Guidance Document: ConstManagement for Remedial Action and Remedial DesContainment Systems

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xvEPA

United Statss Of tec c:f So'.d Waste amiEnvironmental ^roltctior. Emergency Rcsponaa•Vj>wcy Washington, DC 2CMSO

SupBrtund ~"~^~"'" ~~~~ EP^5'*0 '9^^ 7~~~~.

Technical GuidanceDocument

Construction QualityManagement for RemeAction and Remedial DWaste Containment Sy

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United StatesEnvironrnemaJ Protection

Oflx:<3 c't Scvd Waste .inciEmsrgoncy ResponseWashington. DC 2C460

Supsrfund

Off.cc o? Research andDevelopmentWa«'«ing>!on. DC 2i

"Cctober ',992

xvEPA Technical GuidanceDocument

Construction QualityManagement for RemedialAction and Remedial DesignWaste Containment Systems

EPA/540/R-92/073October 1992

Technical Guidance Document

CONSTRUCTION QUALITY MANAGEMENT FORREMEDIAL ACTION AND REMEDIAL DESIGN

WASTE CONTAINMENT SYSTEMS

by

Gregory N. Richardson

Hazen and Sawyer, P.C.Raleigh, North Carolina 27607

Contract No. 68-CQ-OQ68

Project Officer

Robert Landroth

Waste Minimization, Destruction & Disposal Research DivisionRisk Reduction Engineering LaboratoryU.S. Environmental Protection Agency

Cincinnati, Ohio 45268

Superfund Technical Support Center for Engineering and TreatmentTechnology innovation Office

Office of Solid Waste and Emergency ResponseU.S. Environmental Protection Agency

Washington, D.C, 20460

In Cooperation With

Risk Reduction Engineering LaboratoryOffice of Research and Development

U.S. Environmental Protection AgencyCincinnati, Ohio 45268

•* r lE.'.-.V

DISCLAIMER

The preparation of this document has been funded wholly by the UnitedStates Environmental Protection Agency, it has been subjected to the Agency'speer and administrative review, and has beon approved for publication as an EPAdocument. Mention of trade names or commercial products does not constituteendorsement or recommendation for use.

FOREWORD

Today's rapidly dovoloping and changing technologies and industrialproducts and practices frequently carry with them the increased generation of solidand hazardous wastes. These materials, if improperly dealt with, can threatenboth public health and the environment. Abandoned waste sites and accidentalreleases of toxic and hazardous substances to the environment also have Importantenvironmental and public health implications. The Risk Reduction EngineeringLaboratory assists in providing an authoritative and defensible engineering basis forassessing and solving these problems. Its products support the policies, programs,and regulations of the U.S. Environmental Protection Agency; the permitting andother responsibilities of State and local governments; and tho needs of both largeand small businesses in handling their wastes responsibility and economically.

This document provides design guidance on final cover systems forhazardous waste landfills and surface impoundments. We believe that tho finalcover, if properly designed and constructed, can provide long-term protection ofthe unit from moisture infiltration due to precipitation. Tho cover syscem presentedherein is a multilayer design consisting of a vegetated top layer, drainage layer, andlow-pormeabi!Hy layer. Optional layers which may be reqi:;red for site-specificconditions aro also discussed. Rationale is provided for the design parameters togive designers and permit writers background information and an understanding ofcover systems.

This document is intended for use by organizations involved In permitting,designing and constructing hn/ardous and non-hazardous wnsU' land oisposalrac.Uias and in remediating uncontrolled hazardous waste sites.

E. Timothy Oppelt, DirectorRisk Reduction Engineering Laboratory

ABSTRACT

This Technical Guidance Document is intended to augment the numerousconstruction quality control and eonslriict.on quality assurance (COC and CQA)documents that are available for materials associated with waste containment systemsdeveloped for Superfund site remediation. In general, the manual is onented to theremediation project manager (RPM) who must administer these projects.

This document reviews the significant physical properties associated with theconstruction materials used in waste containment designs and reviews the samplingand acceptance strategies required for Construction Quality Management The firstchapter reviews the minimum Federal regulatory requirements for waste containmentsystems Key elements of these systems arc Identified The second chapter icviewsthe key ohvscal p operties TV! rer>f'~jr~-?)"~r '^t^ '011 r^ i~ vr^i*. '>-n-r p-~rr-'r-The thifd chapter reviews sampling methods and acceptance cr«tona that are usod toverify key physical properties during construction

Iv

TABLE OF CONTENTS

DISCLAIMER iiFOREWORD iiiABSTRACT ivLIST OF FIGURES viiiLIST OF TABLES ix

SECTION 1.0 Construction Quality Management

1.1 CQA/CQC Objectives 1-21.2 Regulatory Waste Containment Systems/Objectives 1-5

Surface) Impoundments (40 CFR 264 Subpart K) 1-5Waste Piles I40 CFR 264 Subpatt LI 1-5Landfills (40 CFR 264 Subpart N) 19On-site Waste Isolation (40 CFR 300 App.D) 1-9

Caps 1-9Horizontal Barriers 19Vertical Barriers 1-12

1.3 Components and Elementsin Waste Containment Systems 1-12

1.4 References 1-16

SECTION 2.0 Summary nf Construction Elements and Key Properties

2.1 Hydraulic Barriers 2-1

Geomembranes 2-1Geomembrane Interlocking Panels 2-3Grouts 2-4Bentonrte Products 2-4

Bemonite Amended Soil 2-5Geosynthetic Clay Liner (GCL) 2-5Bentonite Slurries 2-5Concrete/Bentonite Slurry 2-6

Compacted Clay Ltnfirs (CCL) 2-6

TABLE OF CONTENTS (continued)

2.2 Hydraulic (Both Liquid and Gas)Conveyances 2-7

Natural Drains and Collectors 2-7Geosynthetic Drain/Collector 2-9Plastic Pipo 2-9Sumps 2-10Pumps 2-10

2.3 Filters 2-11

Sand/Gravel Filter 2-11Geotextile Filter 2-11

2.4 Erosion Control 2-13

Vegetation and Topsoil 2-13Hardened Layer 2-15

Asphalt Cap 2-15Concrete Cap 2-15Rip-Rap Cap 2-16

2.5 Protective Layers 2-16

Biotic Layer 2-16Geotcxtile 2-18Soil Protective Layer 2-18

2.6 Earthwork 2 1 8

Structural Fill 2-20Soil Bedding Layer 2-20Geotextile or Geogrid Bedding Layer 2-20

2.7 References 2-20

vi

TABLE OF CONTENTS

Tabts No. Page No.

SECTION 3.0 Reid Sampling Strategies

3.1 Delineating the Area or Lot Being Tested 3-23.2 Determining the Number of Sample Locations 3-2

Sample Density Method 3-2Error of Sampling Method 3-4Sequential Sampling 3-7

3.3 Solocuon of Sample Locations 3-9

100% Sampling 3-10Judgmental Sampling 3-11Fixed Increment Sampling , , '. . , 3-13Random Sample Selection 3-14Sample Random Sampling 3-15Stratified Random Sampling 3-17

3.4 Acceptancc/no]ociion Criteria 3-19

No Defects Criteria 3-19Statistical Value Criteria 3-17Maximum Number Defects Criteria 3-24Assigned Variable Monitoring (Control Charts) 3-24

3.5 References , 3-30

AEEENCICES

A - Waste Containment Element Test Methods A-1

B - Standardised Test Methods-Organization Address List B-1

C - Sample Specification for Geomembranewith Sampling, Testing and Acceptance Criteria C-1

vii

List of Figures

£aae.,No.-

1-1 Surface Impoundment Used for Storage . 1-6

1-2 Cover System for Surface Impoundment/Landfill Closure 1-7

1-3 Waste Pile Used for Interim Waste Storage 1-8

1-4 Landfi!! Used for Hazardous Waste Storage 1-10

1-5 Hardened Closure Systom 1-11

1-6 Vertical Barrier System . 1-13

3-1 Delineation and Measurement of Sample 3-3

3-2 Number of Samples - Error of Sampling Method 3-6

3-3 Number of Samples - Sequential Sampling 3-8

3-4 Geomembrane Panel and Scam Identification , , . . , 3-12

3-5 Geomembrane Seam Repair Log 3-1 2

3-6 Normal Distribution of Data 3-20

3-7 Control Chart Table 3-27

3-8 Control Chart to Identify Outliers - Failure Ratio ' 3-28

3-9 Control Chart - Subgroup Sensitivity 3-29

viii

Page No.

1-1 Waste Containment Components and Elements 1-15

2-1 Barrier System Element Testing/Inspection 2-2

2-2 Hydraulic Conveyance System Element Testing/Inspection 2-8

2-3 Filter System Element Testing/Inspection 2-12

2-4 Erosion Control Element Testing/Inspection 2-14

2-5 Protection Layer Element Testing/Inspection 2-17

2-6 Earthwork Element Testing/Inspection 2-19

3-1 Examples - Sample Density Method 3-5

3-2 Portion of Random Number Table 3-16

3-3 Example of Random Sample Selection from 25 Items 3-18

3-5 Recommended Percentage of Low Test Results 3-22

3-6 Required Mean Test Value 3-23

3-7 Statistical Data - Clay Liner Dry Density 3-25

ix

SECTION 1.0

Construction Quality Management

The purpose of tills document is to define procedures that ensure construction materials andpractices used in waste containment installations meet the project specifications and ttterequirements of related remedial settlement orders. The specific objectives are:

* Define Construction Quality Management (COM) and the responsibility of theparties involved in the project

Define and list live waste containment s300

i described in 40 CFR 240 and

Identify components used to construct thu wastu containment systems

Identify the filgflisfljs that are used to assomblu these components and the keyprcpei'iies of these elements that require testing in the field to measure thequality of the constructton

Present sampling methods to obtain unbiased representative samples from thesekey elements

Present examples of how to implement 'these sampling methods on selectedelements.

This document is written for the dusign engineer responsible for preparation of projuct plans,specifications, and tho COM program, and the £PA remedial project manayar (RPM) chargedwith Implementing the COM program. The document focuses on those factors mostsusceptible to field construction problems. It is assumed that the materials to be used at eachsite have been designed (thickness, type, etc.) and evaluated (EPA Method 3090. etc.) byothers. Oi&so elements are assumed to meet the applicable or relevant and appropriaterequirements (ARAR) for the site as determined in the remedial investigation and feasibilitystudies (Rf/FS) process under CERCLA (1).

COM is defined as tho pro-active planning, deve'opment and implementation of bothConstruction Quality Assurance (CQAi uivd Construction Quality Control (COO throughout theproject. In order to ensure a functional and sale wastu containment system, quality must be

nt in atl phases of the project, including: '

1-1

• Pre-construction phase• conceptual design

• design• preparation of project specifications• preparation of CQA/CQC documents

Construction phase» material property• installation testing

• Post-Construction phase* care of installation until it goes Into service* inspection and maintenance of the facility* operations

While COM must ba included in every phase of the project and a system of testing arsdoversight must be used throughout the project, the focus of this document is COM during theconstruction phase of the development of a waste containment system.

1.1 CQA/CQC Objectives

Construction Quality Assurance (CQA) consists of a planned series of observations and tests toensure that the fina! product meets project specifications. CQA plans, specifications,observations, and tests are used to provide quantitative criteria with which to accept the finalproduct.

On routine construction projects, CQA is normally the concern of the owner and is obtainedusing an independent third party testing firm. For the waste containment applications coveredby this guide, the CQA program is also commonly a certification too! used by EPA to ensurethat the project is properly impiemerrted. The independence of the third party Inspection firm Istherefore of great importance. This is particularly true when the owner is a corporation orother Segal entity that has under its corporate 'umbrelta' the capacity to perform the CQAactivities. Although these CQA personnel may be registered professional engineers, there mayexist a perception of misrepresentation if the activity is not performed by an independent thirdparty.

The COA officer should fully disclose any activities or relationships with the owner whsch mayimpact his impartiality or objectivity. If such activities or relationships exist, the CQA officer

1-2

should describe actions that have or can be taken to avoid, mitigate, or neutralize thepossibility they might offset the CCA officar's objectivity. ReguJaiory ruprcisuntativos can thenevaluate whether thfise mechanisms are sufficient to ensure an accuptuble CQA product.

Construction Quality Contro! 1CQC) is an ongoing process ol measuring and controlling the

characteristics of the product in order to meet manufacturer's or project specifications. CQC is

a production tool that is employed by the manufacturer of materials and contractor installingthe materials at the site. CQA, by contrast, Is a verification tool employed by the facility

owner or regulatory agency to ensure* that the materials and" installations meet projectspecifications. CQC is performed independently of the CQA Wan. For example, while ageorrsembrane liner installer will perform CQC testing of fieid seams, the CQA program will

require independent CQA testing of those same seams by a third party inspector.

ill* ^u'A/v.uO piai.h aru icr.pltiiiuiineu tr.iuugji uibpoi,:i<ji. dotiv.;iu» wliiwi i.-iuuoo vi^uilobservations, field testing and measurements, laboratory testing and the evaluation of the test

data. Inspection uciiviuus aie typically concerned with four separate functions:

Quality Control (PC) InspccttonJkv ...d^MaQ fogjMEfit provides an in-process measure ofthe product quality and its conformance with the project plans and specifications.

Typically, the manufacturer will provide CQC test results to certify that the product

conforms to project plans and specifications.

n Quality Control (COCl inspection by iha Conrraciof provides an in-process

measure of construction quality and conformance with the prnjeet plans andspecifications. This allows the contractor 10 correct the construction process if thequality of the product is not meeting tiiu specil.calions unU plans.

Qwn°.r Inspection),

performed by the owner usually through the third party testing firm, provides a measursof the final product quality and its conformance with project plans and specifications.

Due to the size and costs of a typical remedial action/rerrmdlaJ dosign JFIA/RD} project,rejection of the project at completion would be costly to all parties. Consequently,CQA testing takes place throughout the construction process. This allows deficienciesto be found and corrected before they become too large and costly. CQA represents animportant tool to EPA to ensure that the remediation is properly implemented.

rtej.i.iiai.u."v is. oUun pcilumuil ky u ruyuiutory Jgcncy to lliCH the hnalproduct conforms with all applicable codes and rerjsilntions. In sorre cases theregulatory agency will use the CQA documentation and the as-built plans or 'record

drawings' to confirm compliance with the regulations.

1-3

EPA Report 530-SW-8G-031 <NTJS PD87-132825) emitted "Construction Quality Assurance forHazardous Waste and Lane! Disposal Facilities" sets forth key items that should be included inthe CQA/CQC Plan:

1)

2)

3)

4)

Responsibility and Authority - The responsibility and authority of the variousorganizations and personnel involved In permitting, designing, and building thefacility should be described.

Personnel QuaGfications - The qualifications of the CQA officers and supportingCQA inspection personnel shouirf he presented.

Inspection Activities - The observations and tests that will be used to ensure thatthe construction or installation meets or exceeds ail design criteria, plans, andspecifications for each component should be described.

Sampling strategies - The sampling activities, sample sire, methods for determiningsample locations, frequency of sampling, acceptance and rejection criteria, andmethods far ensuring that corrective measures are implemented should bepresented.

5) Documentation - Reporting procedures for CQA activities should be described indetail in the COC/CQA plans.

The responsibility and authority of p,-o}ect organizations and personnel (item 1 above) areincluded in the above EPA Report and will not be discussed here. Guidelines for thequalification of personnel (item 25 are also included in the CPA report, but are being revised andwill be presented In an upcoming document. Currently, a program to certify CQA inspectors isadministered by the National Institute for Certification of Engineering Technicians (NICET).Inspection activities for specific components of a waste containment system have beenpresented In a variety of EPA papers and Technics! Guidance Documents (TGDs) (2. 3. 4, 5, 6,7) and will only be summarized in this report.

This guidance document begins with a brie* overview of waste containment systems andcomponents along with the key physical properties that require monitoring during constructionand installation. A major focus of this document is ths sampling strategies and acceptancecriteria which are used in the CQA plan (item 4). Suggested CQA documentation requirementsare provided In sevcra! EPA TGDs detailing waste containment components (8, 9, 10).

1-4

1.2 Regulatory Waste Containment Systems and Objectives

Under current RCRA arid CtftCLA regulations, there are four distinct waste containmentsystems: surface impoundments, waste pltes, landfffis, and on-site isolation. Eachcontainment system te built of components with distinct engineering functions, (e.g. moisturebarrier, reinforcement, drainage, etc). In turn, each component is composed of elements , i.e.,Individual materials or products, that have particular field inspection requirements. Thischapter provides a brief overview of the four waste containment systems and their majorcomponents. Chapter 2 describes the elements and their respective CQA fieW testingrequirements. Chapter 3 reviews common field sampling strategics and acceptance criteriaand provide examples of their application.

Surface Impoundments

These are basins used to store or dispose of primarily liquid wastes. If the system is plannedto be removed alter the operating life and the site cleaned of aH contamination, then it isconsidered a storage unit. If the waste is stabilized, the free liquid is removed, and the systemis closed and monitored, ihon it is a disposal unit. Surface impoundments can include liners,leachate collection systems, leachate detection systems, and gas collection systems. If thefacility is designed as a disposal unit, then a closure system is necessary.

Under the Federal requirements for the design and opciiilions lor surface impoundments (40CFR 264. subpart K, 264.220 to 264.231S and EPA's design, construction and operationguidelines (Technical Resource Document 5 30-SW-91-054) (10), a surface impoundment mustinclude tho components and cSements shown on Figure 1-1. A typical cover profile used whena surface Impoundment is closed without waste removal is also shown on figure 1 2.

Wnste Piles

These are structures in which waste can be Treated andtor stored temporarily. A waste pKesystem must have a similar bottom liner system as the surface impoundment but will not havea final cover since tt is only a temporary structure. However, waste piles must be covered bya structure which keeps precipitation, wind and surface water run-on awsy from the waste.Typically, these protective structures are simple metal buildings, although other protectivecover may be used. For example, a geomembrane can be used to cover Use waste. Thevarious components and elements of waste pilqs as required by Federal regulations (4-0 CFR2G4 subpart t, 264.250 to 264,259) are shown on Figure 1-3.

1-5

RIPRAP ARWOR-

SOIL PROTECTIVELAYER

SECONDARY- CONT

DIKF

LIHESS E SOILFOUNDATION

LOW-SOIL

-LEAK COLLECTION

SURFACE IMPOUNDMENT COMPONENTS AND ELEMENTSREFERENCES: 40 CFR 264. SUBPART K

TRD/EPA 53Q-SW-91-054

LINER SYSTEM CONSISTING OF OKI OR MORE OF THE FOLLTMNG:• COMPACTS) SOIL UWR* BajTOtJTC MOOIF1E9 OM-SITE SOILS• CCCSYNTHEtlC OAY UNO? (CLC)* GEOM5MBRAKC

LEACHATE COLLECTION SYSTEM or LEAK DETECTION SYSTEM• GRANULAR SOtt. OR GEOSYNTOCnC SJ^AWACF tAYE1?• PIPES.• SUMPS. /WO• PUMPS

GAS VENTING SYSTEM IF ORGANIC SOLS ARE PREKFNT BSNFATH me LINE'?• &?ANIX.\S SCIL OS CtCSvNTHFTir DftAWAGC L/.YSR• VCTT PPES OS FLAPS• GSlOItXTIIF RLTEP TX> s>tOTtLt WANAr.f LAYER

UNER PROTECTION COVER T0 PROTECT T FROW ccNSTWoraw. UEATHFR. ANOui iun. r-nvii.wiiui<( v^^vt-r^ OPFIAtlCTW DAMAGC

• SOIL OR GEOTEXDLE PROtfiCTIVf t^^R OVER L»£P• STCNC O=J RIP-RA? ABQVF IIWD LEVC- TO PRFVENT =HO5ICN ANC OAt.<:=lM W.\V5

SURFACE WATER MANAGEMENT SYSTEM• DIVERSION OITCH6S AKD SBftiS.• MLETS. P3=ES, MANHCLCS• ANO R £ T -

VOLATILE ORGANIC COUMPOUND EMISSION CONTROL SYSTEM• CCWPtfiSE £HCtOSUR£, EG MR BU88U• SUS^ACE HARRIS? OR FLOATING CO'(ER OT FOAM. OS, 01! G£OtCMBRANE• WfE> DIVERSION FENtX

STABLE FOUNDATIONGROUND-WATER MONITORING WO1.SLIQUID LEVEL CONTROL SYSTEM CONSSTKS cr ETMER AN ACtivr S

US»!C PUMPS OR A PASSIVE SY5TFM USf*0 A SOILL 'AYSECONDARY CONTAINMENT SYSTEM SUHWWWINC OJ-RE SUP.FACC

FIGURE 1-1 SURFACE IMPOUNDMENT USED FOR STORAGE

1-6

fflOTIC BAIRIEfi(COBBLES)

LOW-PERMEABIUTY«EOMEUBfUNE/SOIL LAVES

BEODiHC LAYER(IF REQUISSO)

MIK 30-m» (0.73mm) GEOMEM8RA>i£W/OVESLYIMC- PROTECTIVE KOTEXJILL

SURFACE IMPOUNDMENT AND LANDFILL COVER SYSTEMREFERENCES: 40 CFR, SUBPART K

TRD/EPA 530-SW-91-054

PROTECTIVE COVER VEGETATIVE CR ".ARDCNEU EROSON CONTROL sum- ACEVEGETATO>J 3*

CF RP-RAP. ASPHA-T, CK C3HCU( If* pnomeuvE son IAYPI

BIOTIC BARRIER TO UMIT DF B.JRROWNS ANIMALS AND TAP• COB8LES. STCKS& OR HAJB^NKD SARSsfR• WOTEXTILE I1LTLR HJ CfMIASH ADJACQ.T

SURFACE WATER DRAINAGE LAYER« ffiUWULAR SOIL OR CecSWTHFTIC« CCOtHXTlLE FILTER

LAYER

LOW PERMEABILITY BARRIER COM-SISTW y- IMF o? coir c.r• COMPACTED SCIL' UNO*

AMENDED OK-SI1 &0C..AY tNER (ac)

(KWJF.VRRA'JE

GAS COLLECTION SYSTEM ir WASTE v»*_ GOIEKAT« GRANUtAR SOL Oft CEOSYNtHEK DKAIKAW 4.AYFR• VEK7 Plf S• CEOTEXTl£ «n,TES TO PROTECT DRAINAGE ^

BEDDING LAYER ovw WASIT TO PROSTOE STABLE• CN sre s><.

OCX'N

STABLE WCfiKlrcS PLAT^CIW

S \jiltf

'

-' 1* iV

j1

1 !

! i

URFACE IMPOUNDMENT/LANDFItL CLOSURE

1-7

smutstittt oiSS2SI-OK. A.M0

psofsftr WAST* nwvKiPBSM. B? Mo.

lEUPAJE COLLETICHAMJ ptsiyrrcnvrSSWOV11. STCTCW !C»L AND COVES

(npto--*)

GCCME1483AXE

COMPACtEO SCO. CONPCWBf?W BOTTOM COMPOSITE USrtK

WASTE PILES FOR INTERIM HAZARDOUS WASTE STORAGEREFERENCES: 40 CFR 264. SUBPART L,

264.250 TO 264.259

LINER SYSTEM CONSISTING SF O^E OR• CCMPACTED SOI. UHFR

rc VTOCiFBD W-SITE SCIt RCLAY L'NER (GLC)

y- ME

LEACHATE COLLECTION SYSTEM or LEAK DETECTION SYSTEM• GRANULAR SOL OR GSOSYNTHET1C BRWACE LAYER

SUSP'S. ANDPUMPS

GAS VENTING SYSTEM IF CRGAMC sos.s ARE PRESET BENEATH THE _I«R• Ct?AlsSJl.AR SOf. CP C'OSYHT-'f'lC WJA'NACE lAYtt• VENT 5=!Fi;S CR FI FS• GEOTEXDLE HLTtR TO PPOPTC- DRAINAGE LAYO

LINER PROTECTION COVER ro ^OTICT >- rac« COMSTRUCTON. AEATIEI. -woOPERATIONAL DAMAGE

• SOIL O>5 GEOTCXTJte P^OTECTiVt LAYfK OVER UNLR• STONE OS RIP-RAP ABOW I ICUO tEVfcX TO PRf VT->»- tROjICH AND SAMFF.N WAVF ACIXW

SURFACE WATER MANAGEMENT SYSTEM* DIVERSION DITCHES AMD DES' S,• INLETS, PIPES, ISANHOLES

BASINS

CCMPLOE KICLCSURE, E.a AIR BUBBLESURFAC6 8ARRIEH CR fUOATlhW COVES CF FOAW, (XI. OX CXOWEMSRAKE

STABLE FOUNDATIONGROUND-WATER MONITORING WELLSLIQUID LEVEL CONTROL SYSTEM CCNSSTKS er OTHER AH ACTIVE

USING 5-JVPS OR A PASSIVE _gYSTFM OSNO A SPIJ.WAY -

SECONDARY CONTAINMENT SYSTEM H. OJNOINC -M-n=e iuppArr vra U

FtGURE 1-3 WASTE PILE USED FOR INTERIM WASTE STORAGE

1-8

Landfills

These are final disposal units for solid and hazardous wastes- I aodfills have the samecomponents and elements as the surface impoundment disposal uruts. Under the requirementsfor the design and operation of landfills {40 CFR 264 subpart N, 261.300 to 264.317) and thedesign, construction and operations guidelines presented in EPA seminar publications (11, 12),

a landfill should include the components and elements shown on Figure 1-4.

Qn-SHa Waste Isolation

Remedial actions to Isolate uncontrolled releases; of contamjrvates are described in 40 CFR 300"Appendix D - Appropriate Actions and Methods of Remediating Releases." Wastu isolationsystems include caps built over waste to minimize infiltration of rainwater, and both horizontalbarriers under the waste and vertical barriers at, the lateral extent of the waste to prevent

uncontrolled release of leachote {12, 13, 14). Tfiose are systems which are consuuctu-d on

remediation sites to isolate and allow for the treatment of a/i uncomalned wasiu.

Caps

Waste facility caps reduce water infiltration, control gas and odor emissions, improve theaesthetics, and provide a stable surface over the waste. A composite barrier capping system(Figure 1-2), is required for tho closoro of hazardous waste storage facilities (1 2, 1 3). AMuruY'itcd c:a;i is typically required til an arid olimatub where a vegetative cover wdl not survive,in urban areas where vegetation may be undesirable, or at industrial facilities where it wou'd boadvantageous to continue using the site. The hardened cap iiiloyrates the vegetative layer,protective layer (biotie) and drainage layer into or.e layer as shown in nguro 1-6. The hardenedcap can be constructed using "hard" elements, such .as graded stone, asphalt, or concrete.

Note that the use of a hardened surface layer does not eliminate the need for thegeomarnbrane/clay moisture barrier components in the cap.

Horizontal Banters -

Horizontal barriers are installed betow an existing wastu mass to contain the waste and prevent

the movement of contaminate into the surrounding soil and water. Horizontal barriers are verydifficult to inspect due to the overlying waste.

Horizontal barrier techniques involve the. injection of grout uridur thu waste using one of thefollowing methods:

1-9

PROTECTIVESO1U AND COVER(opicr.ol)

PRIMARY l£ACHATk-COUXCTIOK AND

REMOVAL SYSTEM

TOP UKER(C£OM£WeR(HAZARDOUS WASTE ONLY)

SECONDARY- fiOl I FfTtBM AND .

SYSTEM ««IKOATQNWASTE ONLY) OKOMEMSRANE COMPONENT \

OF COMPOSITE L.HD5

COMPACTED SOIL COWPOMENTOF aOHOM COMPOSITE IWER

LANDRLLS - LONG-TERM HAZARDOUS WASTE DISPOSALREFERENCES: 40 CFR 264, SU8PART N

EPA 625/4-91-025, EPA 625/4-89-022

UNER SYSTEM CONSSWO o^ ON-: OR MORE (? THE Fai OWNC :SOL L*SR

MOPIFSP ON SUE Sgi.fiGEOSYNTHETTC a/.Y I \t^K (ra C)

LEACHATE COLLECTION SYSTEM or LEAK DETECTION SYSTEM• GRANULAR SCIL flR CCOS\N'?WtIC MANAGE I AYE»• PIPES,• SWPS, AMP• PUMPS

GAS VENTING SYSTEM IF ORGANS socs ARE PPCSCM" BOKATH TW: UN.-ER• CRA^JLAR SOL OR aEOSYNTHETIC DSAINjdCE LAYB?• VENT P!PSS OS PtAPS• GEOTCXTlt FlLtES TO PROTECT DRAINAGE IAYER

UNER PROTECTION COVER TO T PROM CONSTRUCTIOM. HEATWR.PAHAfiC

SOIL OR. C£OTEXTs.E PHOTECTiVE LAYER O'.XR UNSRSTCSNS OR KP-Kff Ai3O^ UGWO LT/Ei TO PREVENT

SURFACE WATER MANAGEMENT SYSTEMKVES30M CITCSfES */« OERWS.

PIPES, MAMKX£SDASHS

WNDENCLOSURE, £.S. />» BUBBLE

BARfi)E« OF FOAV (» flEOMEMRRANE.FENCES

STA8LE FOUNDATIONGROUND-WATER MONITORING WELLSLIQUID LEVEL CONTROL SYSTEM COHSSTWC or EITHER

> PUMPS OR A PAsavr srsnat USNQ ASECONDARY

«CTWE_SYSTEV

FIGURE 1*4 LANDFILL USED FOR HAZARDOUS WASTE STORAGE

1-10

3-f (7.5-10 cm) Atphollpaving (2 courjo)

— 10"*f '•la* Mopi,

Budding _<j

— >te. *<!&.r~-^R ^sr

* or gle

(o) Asphalt Cap

4-«T (10-IS cm)

V (10 en) Concr<rio(6x6 Vrt-« Roinf

Lay*ir

* or gle

(o) Concrule Cap

eoloxlt,!! FIHor Ctarh —7 j

'>Q'n ~\NVJ/-^\ Nl—/--*

• or gl=

(c) Graded Stone Cap

* or g(o

(d) Multi - Media Cap

FIGURE 1-5 HARDENED CLOSURE SYSTEM

1-11

• vertical borings drilled through the waste snd pressure injection or rotary Jetting ofthe grout beneath the waste,

• horizontal borings drilled bulow the waste from trenches and pressure injection ofthe grout beneath the waste.

• block displacement method which surrounds ilie waste with a vertical grout wailand then injects low pressure grout beneath the waste. The entire waste block israised In this process (15).

All of these mathoris require that tho borings be spaced dose enough together that the groutbulbs or lenses overlap and form a continuous barrier. Verification of the overlap is critical butvery difficult. Potential inspection methods are. limited to test excavations, oxplorato'v borings,anrj observed impact on ground water if the barrier is placed beneath the ground water table-

Vertical Barriers —

Vertical barriers are wall-like systems used to isolate any contaminates that have teached fromthe waste and that are moving laterally, fo to affective, these barriers should intercept acontinuous impervious horizontal layer below tho waste. This bottom layer can be a naturallyoccurring layer such as an aqulclude, or a horizontal barrier. Sevp.ral types cf vertical barriersore commonly used, including:

• Slurry wall. A trench surrcundiny the waste, lilleo" wit.'i o soil bentonita ana.-orconcrotc-bentonite slurry.

• Grout curtain. Grout Is injected in a scries of vertical columns that surround thewaste, creating a continuous curtain.

• Geornernbrane curtain. Intn.'Iccldng geomembranc panels arc placed in a verticaltrench surrounding the waste. In some cases thu gaorncrnbranc Is used inconjunction with the slurry wall to form a composite liner system.

Schematics of ffrcut curtains sncl qeomembrane curtains Bra shown in Figure 1-6.

1.3 Components and Elements in Waste Containment Systems

The regulatory wasts containment systems reviewed in Section 1.2 are constructed using asmall family of functional components. These functional components include:

1-12

o. GROUT CURTAIN VERTICAL BARRIER

ImperviousSSfaiusn 7 Perforated Drain Pipe

b. GEOMEMBRANE VERTICAL BARRIER

FIGURE 1-6 VERTICAL BARRIER SYSTEMS

1-13

Hydraulic BarriersHydraulic ConveyancesFilter LayersErosion Control LayersProtective LayersEarthwork

Each of these basic building blocks is in turn composed of distinct physical elements as listedon Table 1-1. It is important to understand that project specifications and the constructionquality management program will focus on elements and not components. Thus projectspecifications for a hydraulic barrier will provide guidance for clay or geomembrane propertiesbut will not identify functional properties of the overall hydraulic barrier. This documenttherefore examines construction quality management at an elemental Ipvel.

1-14

TABLE 1-1 WASTE CONTAINMENT COMPONENTS AND ELEMENTS

ELEMENTS

HvdrauSic Barriers

I Ivdraulic Conveyances(Both Liquid and Gas Conveyance)

Filter Layers

Protective Layers

Earthwork

GeomembranesGeomembrane Interlocking PanelsGroutsCompacted SoilBentonite Products

Soil-Bentonfte BlendsGaosynthetie Clay LinerDontonitu SlurriesConcrete/Bentonite Slurry

Natural Sand/Gravel Dram/CollectorGeosyntheiic Drain/ColiectorPipeSumpsPumps

Sand/Gravol FilterOeolu-xtilt;

Stone and Rip-RapVegetation and TopsoilGuosynthutic Lrosion Control Products

Hardened LayerB*otic LayerGeotextileSoil Layer

Soil Foundation or Bedding LayerSoil EmbankmentsGaotextilo Separator

1-1S

1.4 References ,

1-1 - U.S. EPA. 1988. Guidance for Conducting Remedial Investigations ami FcasibifityStudies under CERCLA, Interim Final. Office of Emergency and Remedial Response,Washington, DC 20460.

1-2 - U.S. EPA. 1984. Quality Assurance Handbook for Air Pollution MeasurementSystems: Volume 1 Principles. EPA 600/9-76/005, Environmental MonitoringSystems Laboratory, Research Trtanglo Park. MC 27711.

1-3 - U.S. EPA. 1986. Construction Quality Assurance for Iteardous Waste LandDisposal Facilities. Technical Guidance Document EPA 530-SW-86-031, Office ofSolid Waste and Emergency Response, Washington, DC 20460.

1-4 - U.S. EPA. 1987. Geosynthetic Design Guidance for Ha/ardous Waste Landfill Cellsand Surface Impoundments. EPA 625/4-89/022, Hazardous Waste EngineeringResearch laboratory. Office of Research and Development, Cincinnati, Ol I 45268.

1-5 - U.S. EPA. 1989. Requirements for Hazardous Waste Landfill Design, Construction,and Closure. Seminar Publication EPA 62S/4-89/022, Center for EnvironmentalResearch Information, Office of Research and Development, Cincinnati, OH 452(58.

1-5 - U.S. EPA. 1991. Inspection Techniques for the Fabrication of Geoinernbrane FieldScams. Technical Guidance Document EPA 530/SW-91/051. Risk ReductionEngineering Laboratory, Cincinnati, OH 4S?68.

1-7 - U.S. EPA. 1989. The Fabrication of Polyethylene FML Reid Seams. TechnicalGuidance Document EPA 530/SW-89/069, Office of Solid Waste and EmergencyResponse, Washington, DC 20460.

1-8 - U.S. EPA. 1988. Guide to Technical Resources for the Design of Land DisposalFacilities. Technology Transfer Document FPA 625/6-88/018, Risk ReductionEngineering Laboratory, Cincinnati. OH 45260.

1-9 - U.S. EPA. 1984. Permit Applicants' Guidance Manual for Hazardous Waste LandTreatment, Storage, and Disposal Facilities - Final Draft EPA 530 SW-84-004,Office of Solid Waste and Emergency Response, Washington. DC ?0460.

1-10 - U.S. EPA. 1083. Handbook for Evaluating Remedial Technology Plans, MunicipalEnvironmental Research Laboratory, Research and Development Document EPA-600/2-83-076, Office of Research and Development, Cincinnati, OH 45268-

1-11 - U.S. EPA. 1991. Design, Construction, and Operation of Hazardous and Non-Hazardous Waste Surface Impoundments. Technical Resource Document EPA530/SW-91/OS4, Office of Research and Development, Washington, DC 20460.

1-12 - U.S. EPA. 1991. Design and Construction of RCRA/CERCLA Final Covers. SeminarPublication EPA 625/4-91/025, Office of Research and Development, Washington,DC 204SO

1-13 - U.S. EPA. 1989. Final Covers on Hazardous Waste Landfills and SurfaceImpoundments. Technical Guidance Document, EPA 530/SW-89/047, Risk

1-16

Reduction Engineering Laboratory, Cincinnati, OH 45268.

1-14 - U.S. EPA. 1991. Conducting Remedial Investigations/Feasibility Studies forCERCLA Municipal Landfill Sites. Technical Guidance Document EPA 54CW-91/001. Office of Emergency Remedial Response, Washington, DC 20460.

1-15 - U.S. EPA. 1987. Block Displacement Method Field Demonstration andSpecifications, EPA 600/2-87/023, Risk Reduction Engineering Laboratory,Cincinnati, OH 45268.

1-17

SECTION 2.0

Summary of Construction Elements and Key Properties

Construction elements are commonly used as pay units on construction projects end as such

are readily identified. For example, the contractor may b« paid basad on Uis square footage ofgoomembrana installed or the cubic yardage of compacted clay, sand, etc. installed. Specific

references to these elements are made in the project specifications.

This chapter reviews tho elements common to components used in waste containment

systems. Each element will have physical properties defined in the project specifications.Some of'these properties must be verified in the field as part of the construction quality

management program. However, many of the physical, mechanical and chemical properties

cannot ba verified in tho field. In these cases, the construction quality management programmust rely either on certification by the manufacturer or supplier that the material meets project

specifications or conforrnancc testing by an independent laboratory. Key properties or

installation parameters that require verification and corresponding test methods are discussedin this chapter. Standard test methods to quantify malarial properties are identified inAppendix A.

2.1 Hydraulic Barriers

A site munugui should rualize :ha; the performance of 0 barrier system can uxceed thf: sum of

the elements that comprise' it. A well constructed composite finer system, (or example, willhave less infiltration than what is expected from independent evaluations of the clay linur andgaomembrana. Such synerrjlsf.c interaction between elements is net accounted fcr in prcjuetspecifications or the construction quality management program. Table 2-1 identifies hydraulicbarrier systems and elements that require field testing.

Genmembranes

Geomembranes are used as low permeability barriers in both the bottom Imcrs and caps of•.vasie containment sysuiirvs. In a hazardous waste landfi'.l, geomernbi anos can Ou ustid atoneas the upper or primary finer, and in conjunction with a low permeability soil layer to form thelower or secondary composite iiner. Manufacturers and fabricators of geomembrsnes areresponsible for tho quality control of both the raw materials, such as plastic resin, and thefinished sheets. Their Iniurnal quality control (QC) incorporates routine testing of the polymer

and the finished product. Tust results must bs submitted with each lot of ocomernbrancs

shipped to tho site. In addition, certification must be presented with the rjeornembranes

2-1

!>1STALUniCH OUJBJTT VERf KATKI.

' Clffeftl BK<• SMro-'mrftt- HUttiKl CwoUl* U*«3 Trt

ASTMOB13ASTM OlStttt

• Fi»pwiflflfletiti!*«*i EjQ.no

» ft ter » twcryj i i

rodrg at

ASTM^SSMTV ?<3l9

Gwqirtrta

fl rf -K^ flih. jli f»! -i

MfssasSSJtetiS

siating that the materials are In compliance with manufacturer's published information and/ortho project specifications.

A sample of each lot (production run) of geomembraoe material that arrives at the site shouldbe taken. Tests on these samples should confirm that they have the same polymer propertiesrequired by project specifications. This is known as conformance testing and should beperformed by an independent laboratory. A series of samples, instead of one, may benecessary to provide all responsible parties with a sarnplu. Testing of the goomembrane in thefield is typically limited to verification of membfsno thickness, visual inspection for physicaldefects, and a thorough testing of all field seams.

Non-Destructive Testing (NOT) of seams is required for the untire Ismnth of the stiam. Suchtesting is performed using the vacuum box test for single bonded seams or the pressurized airchannel tost for those seams thai have two lines of bonding separated by an air channel. Thevacuum box test applies a moderate vacuum to a seam previously wetted with soapy water,Leaks are indicated by bubbles. The test must be repeated over the entire iungth of the seam.The pressurized air channel test inflates the seam and checks for a loss of pressure. Samplesfor destructive tasting are commonly taken at a minimum of every GOO feet of seam, with aileast one samplu taken per seam. Additionally, samples must be cut at least every four hoursnr when scummg conditions change to provide samples fui dustructivft testing und to monitorvariations in seam quality due to variations in operator or seaming equipment. Tho reader isreferred to the Technical Guidance Document LPA/530/SW-91/051 entitled 'InspectionTechniques foe tho Fabrication Geomembranc Field Seams. Specific test requirements may bepart of the Construction Quality Assurance Manual prepared for tliu project.

Goomembrnne Interlocking Panels

Geomembrane ImufSockinrj panels arc installed in verticci1 trenches to construct a lowptrmRab'liTV harrier Thu panels consist of rnembranR panels that connect along the.r ltinj}Thsmuch like conventional steul sheet piles. The panels are pre-fobricatuti ami assemoled ai thesite by locking the panels together and placing them into the trench.

Geomembrano interlocking panels have two physical elements; high density Polyethylene(HOPE) panels with interlock fittings along their vertical edge, and a soft plastic sealing mediumwithin the Interlock that provides a hydraulic seal to the Interlock fittings. The HOPE interlockclosely resembles that used in conventional steel sheet files: A fusnale channel on one panelthat engages a male edge of an adjacent pane!. Field inspection of thu HOPE panels andhydraulic seal material is generally identical to that required for geomemb.'ane materials. Fieldtesting of the gyamembrane panels is typically limited to verification of panel thickness. TheInterlock seal material is hydrophiSic and swells in the presence of the groundwalei to establisha seal. The manufacturer should be required to provide certification of the long-term chemical

2-3

stability of the hydraulic seal material when exposed to the site-specific contaminant.

Qeomembrane interlocking panels can be installed in open trenches, slurry trenches, or vibratedinto sandy soils using a steel mandrel. Care must be taken to insure that the hydraulicinterlock and seal material properly seat along the entire length of the interlock channel. Thisverification can be difficult in slurry wall ond vibrated installations. The continuity of theinterlock is tested during installation of a new panel using a "runner". The runner consists of a31/2 Inch section of the female portion of the Interlock that is secured to a rope. The runneris installed ahead of tho panel to be installed so that it is pushed down the Interlock by thepanel being installed. The rope Is knotted to show final installation depth. If the runner comesto a halt before the full Insertion depth is reached, the panel must be removed and redriven.The hydraulic seal is marked in a simitar manner, and is not accepted if the seal advance depthis less titan 85% of the panel depth.

Grouts

The grout used in a waste containment system is usually a mixture of cement and buntonile.Grouts are, however, available with silica, acrylato, urethane, and Portland cement binders,Grout can be injected in horizontal or vertical borings using a variety of pressures. Thesuppliers of the grout materials must provide material property data sheets and a certificationthat the materials conform to their specifications. During the mixing of the grout, thequantities of materials used in the mix should be measured and recorded. Once the grout Ismixed. It must he tested to confirm that it meets project specifications for viscosity (Marshalfunnel test), setting time, and strength.

Grout is pressure injected into the ground by specialty contractors. Field monitoringrequirements include documentation uf the mjcc'.ion ioco'iop. dc-pi'i. ptiTpinp ';-.-(-. an:! ~n',n\grout vo'urtiR issed (see Table 2-1).

L

Bentonite

Bentonite provides an effective moisture barrier. Available as either sodium bentonite mined Inseveral western states cr a less active calcium bentonite from Georgia, commercial bentonite ispurchased in powder or pellet form. Tho permeability of bentonite ranges from 10"" cm/sec forcalcium bantonitp. to as low as 10''" cm/sec for sodium hentonite. Bentonite can ba used byitself to form a moisture barrier or blended with on-sita soils to form an acceptable soil Itner.Bentonite is available from commercial suppliers w!io must provide s summary of 1hs materialproperties of the hentanita shipped to the project site and certification that the materials moottheir specifications.

2-4

Bentonite Amended Soil--

When there is not an adequate supply of low permeability soil on site for the construction of a

soil barrier layer, a bentoniio soil amendment can be used to lower the permeability of the en-

sile soils. Typically, s 3 to 6% buritonite amendment by dry weight is sufficient to achieve apermeability of 1 x 10'7 cm/sec using on-site soils. Sands, however, may require as much as

10 to 15% bentonite amendment. The percent bentonite required is evaluated in the laboratoryusing site specific soils. Pro]ect specifications are then prepared to ensure that the soil and thebentonite used in the field replicate that used in the laboratory. Once the bentonite is mixedwith the soil, it should be tested to evaluate the thoroughness of the mixing and tin-

concentration of the bcntanite (12). A uniform mixing of bentonite is essential to thoperformance of the soil-bentoniio liner. This mixing may require a pug mill or asphalt pavementsurfaces to adequately blend the bentonile with on-site soils.

The Installation methods and evaluation of the bentonite soil liner is tha same as that for anunarnonded clay liner. If the bentoniio Is mixed with the soil in placu using a disk, careful visual

observation of the depth of iwxing and ihe covarsge of the benionste over the liner area mustbu made.

GeosynthBtic Cloy Uner (GCL)--

A GCL >s essentially a prs-fabricated low purrnuability soil layer. Tho bontonitc is usuallysandwiched between two geotextiles or adhered to a geomembrano. GCL's are manufacturedin 8 ft. and wider shoots and gre shipped to tliu situ in rolls. Typically the weight of bentonite(or buntonite snd adhesive) per square foot is specified and must be fifild verified.

Tnc GCL barrier is installed by simply unrolling the sheets ovtir a prepared subgrado. Tho

subgrade should be free of large rocks, ruts, and objects that could penetrate through the GCL.Additionally, tho subgrade must be stable, which can be checked by proof-rnllir.g. Seaming ofthe GCL barrier Is typically limited to a minimum 6-inch overlap of adjacunt sheets. The watersua! at the seam forms when the bentonite hydrates and "cozes* out from bciwotm thegootaxtiles. Additional dry bontonite powder may be spread between the overlaps to Improvethe seal.

Bontonttu Slurries-

Bentonite slurries are usod in vertical barrier walls to displace the natural soils snd constant atow permeability barrier. Bentonite slurries are mixtures of /l to 7% bentonite and water.Quantities of materials used in the mix should be measured and recorded. After the mixing,the* buntoniie slurry should be tested for gel strength using g Farm Viscommer. Typical gel

2-5

strengths exceed 15 psf (240 kg/tn?).

The bentonite slurry can be used "as is" to prevent the collapse of cut-off wall excavations orblended with on-slte soils to form a soll-bentonite slurry used in permanent barrier walls. Thesoils should have 20-40% fines and are blended wfth the bentonite slurry until a paste Isformed. This paste should have the consistency of fresh mortar or concrete and flaw easily.

Slurry uniformity is poor when dozers ore used to blend the soil and bentonite. If dozers areused, increased visual Inspection and bentonite concentration testing may be required.

Concrcto-Bcntonitc Slurries-

Co ncrete-bentonite slurries are used on sites where adequate sosls to form soii-bentoniteslurries are not available or when increase strengths are needed. The concrete-bemoniteslurries are mixtures of approximately 18% concrete, 6% bentonite, and 76% water. Theconcrete bsntonite slurry is similar to the buntonttu slurry above and the test methods used inthat section also appiy to this material.

Because of the concrete, the concretc-bentonito slurry will hydrate anil begin smtlng in 2-3hours. Thp. installation must be monitored to ensure that the slurry has not hydratud prior toplacement.

A CCL may be used as the primary moisture barrier in both waste liner and cover systems.Achieving a low permeability in a clay liner requires a suitable clayey soil and properpreparation and compaction of the soil. Test data (4,11) ctoarty demonstrate that thepermeability of a clay liner can be increased 100 to 1000 times if a stngto parameter inpreparation or compaction is neglected. Soil selected for use as a clay liner is specified usingsoil plasticity (Attuiburg Limits) and grain size distribution. Both parameters can be easilymonitored during actual field placement of tho liner.

Construction of a clay liner requires proper soil preparation and correct compaction equipmentand technique. Soils used for clay liners should bo processed to ensure that the soil watercontent is as specified, the soi! clods are no larger than 1 to 2 inches, and the maximumparticle size Is less than required by the project specifications. For composite tinars, themaximum rock size in the last lift Is frequently less than 1.0 inch (2.54 cm) to minimizepotential damage from rocks to the overlying geomembrane. Liner soil preparation is usuallydone as the soil liner material is placed in a stockpile. Significant moist j re adjustment shouldnot be attempted in tho 24 Ivours preceding placement of the soil.

2-6

Key construction guidelines for installing clay linars are related to both equipment andoperation;;. Compaction equipment must havu feat that penetiatc completely through a looselayer of fill. Alternately, the loose lift thickness can be adjusted to maximfze the efficiency ofthe available compaction equipment. Compacted effort (compactor speed and number ofpasses) should be consistent with the minimum effort established in a lest strip. Additionally,bonding between the layers of compacted clay must bo enhanced by scarifying the surfacu ofthe pruvious lift. The as-built clay liner must be tested to verify that it meets projectcompaction criteria. This requires a field sampling program to measure soil moisture contentand density.

A clay liner is very susceptible to damage due to either desiccation or freezing. Clay liners leftexposed must be protected from desiccation using a surface sealant (acrylic sprays or lightmembranes! or an additional layer of "sacrificial" soil. So;! cover also serves to pruventfreezing of the day liner. Even a single cycle of freezing can significantly increase thepermeability of a ciay liner. Testing a suspect sot\ liner for permeability requires usther a large-scale doublo-ring infiitrorneiur test or laboratory testing of imdistuibed (UD) samples takenfrom the soil liner.

2.2 Hydraulic Conveyances {Both Liquid and Gas)

Drainage layer components are designed to coiled leachate beneath tho waste or to colluct gasobovo the waste. Hotfi functions require tho drainage layer to be significantly more permeablethan the adjacent waste or soils. Thus filter systems, discussed in Section 2.3, are required•.•.•i;I- all drainage systems. NRWL-I geucompoKite syatuniti provide Doth iha drainage media andfilter tayor in a s;ngle commercial product. Field testing requirements for hydiauiic conveyancesystems aro presented on Tabte 2-2.

Drains and Collectors

A sand or gravel drainage layer can be used as pan of the leak detection cornponant of awaste containment system, as the primary drainage layer above the bottom liner, and as anInfiltrating storm water drain In the capping system. Soil drains provide a high permeabilitymedium into which liquids can easily drain to a network of collection p<pes. The soil drainusually consists of clean sand or gravel sorted to specific particle sizes by a quarry. In sonnocases suitable sands or gravels are found on site, but this is unusual.

2-7

TABLE 2-2 HYDRAULIC CONVEYANCE SYSTEM ElEMaffTESTIMQ/INSPECTICM

ELEMHfT i MATERIAL PBOPERTISSfPOST COKSTflUCTIOti CASE

Send/Oravei/Dram - MiiMtd PropenJe*: Mature^ Water ContentCol&ctw

Laboratory HftfraUo Condu^wit/

FIELD TEST il?JSTAOATIOH QUALITY VgHlf }CATIO?4

ASTMW22

ASTMD2434

ASH! DS3S

|* An Pbcod Prosxstj- Water CentBra• <n Fleee Density

ASTM D2216ASTMD2322

frsrn fires sefeted to sodtewntation by nuiiber ol passoa «iilh « gK'en csnupacson ogplpnrant

FffitOTEST

VetoM Pwparfes: V'Aaghtp«r»qurxier <OM!, Co^ScrtSoo \1suai

Poo; Cqnstnictta". GKcyTflhctio dtancgo [syers Tust bspnsteoted fcm Sn-noQp ay «?roct teisHKacng of vsKdao, and

cat^c^ by wire* cr man

Avc&j foWo, nrirtMcB, or dairtaga io panels- ProvkSs IsnifKfisry s^eJiofaga,

cs P<slyir«r STOMSHCS, i=fp» ra-'ng

Wai

CcrtiScaiJcnper ASTM 012-.3Visual

Vor3/ pipt perfofaliano, pbewnenl, wd o3rae<S!e«

i Post QuvtinsOGar Pipas IRJS! bo prctostaJ «-otit danagejoy <Sreos trattlVi-ig ol vefiteas snd TCWSITSS- s*fcf to iwfisi

- verily Suoafon area grade o? ppeo test sofei pipa jdmn

rratef ial sutisfbs s^c-jir^* Gran Siro

Suri-ay&Kr Pips Mcn'Buis Fusion

(a»rii Proaarbcs: ^o i'e- prcpsrlias Isoe gtcnwtbfsiw)

vteualVisual

- SjbgreKS) prrpared free o« pcsotai or sharp s&fscW- Bcdd ig !£ycf r&qurco ^ar pmlabncolsd umpVo'ily teoalisn pfid grads of sunp

Post V'crf/ ral=d capoiiy Ailh hydro fesl

Drain materials are specified using a particle size distribution and samples should be taken forlaboratory grain size and permeability conformance testing. Soil drains typically require onlymoderate to light compaction and the as-installed drain layer thickness should be verified.Natural drainage layers must be protected by diversion berms or geotextiles from theintroduction of water borne fines from surface erosion of adjacent slopes.

Geosvrrthetic Drains and Collectors

A gcocomposite drain consists of a core material that provides a pathway for drainage and asurrounding geotextile that prevents clogging of the core. Geocomposite drains can be used aspart of the leak detection component of a waste containment system, as the primary drainagelayer above the bottom liner, and as a lateral drain in the capping system. Similar to the soildrain, a geo composite drain provides a high transmissivity core through which liquids can easilydrain into a network of collection pipes. Geocomposite drains are pre-fabncated and come inrods or panels up to 300 ft. in length.

Geocomposito drains are available from suppliers who must certify thai the materials suppliedmeets the manufacturer's minimum specifications. The CQA officer must compare themanufacturer's specifications with the project specifications. Laboratory conformanco testingshould be performed on the drains under service conditions if differences exist between thetwo specifications. The material delivered to the site should be inspected for generalcornpHanco with project specifications and to check for damage duiing shipping.

installation of the geocon-.posite drain requires no field testing. The drain shou'd bu inspectedto confirm that it is installed according to manufacturer's and project specifications. Overlapsbetween adjacent roll ends or panels are particularly important with the proper overlap length,orientauon, snd plastic ties used to bind the overlap. Geosynthetic drainage layers must buprotected from damage by vehicle traffic, wind ar other disturbances. The layer should also beprotected from fines carried by surface erosion during construction.

Plastic Pines

Both perforated collection and solid transmission pipes are used in the leak detection systems,the primary leachato collection drain, the lateral drain in the cap, snd to carry storrmvater andloachate away from the waste containment system. Collection and transmission pipes areconsirjctcJ from a variety of plastics and can be designed for gravrty flow lines as well as lowor high pressure lines, depending upon the application.

Collection and transmission plpass are available from suppliers who must certify that thematerials meet manufacturer's specifications. The material delivered to the site should bo

2-9

inspected for general compliance with the project specifications and to chec1'. for damageduring shipping.

Installation of collection and transmission pipes should be field inspected to verify that thelocation and grades of the pipe and joints, and the bedding material and backfill meet projectspecifications. Perforated pipes require additional inspection of the perforations (hole diameterand spacing} and pressure pipes require hydrostatic pressure testing (sec Appendix A).

Sumps

Leachate sumps are located In both tho primary leachate collection layer and the bottomrtowerleak detection layer. Sumps are located at low points in the liner and act as basins in whichthe leachata can be collected. From the sumps, the leachate is either drained out of the wastecontainment system by gravity or pumped out. The sumps can be a simple depression in thecomposite liner or a pre-mamifactured plastic basin that is set in the clay liner so that its top isflush with the gecrnembrane liner. The geomcrnbrane is fusion-welded to a flange on theupper edge of the sump. Pre-manufactured sumps eliminate difficu!t~to-test field seams orcomplex grading.

1$ leachate sumps are fabricated on site, than they will be made from the same materials as theliner system, so certification of the liner materials will already have been provided. If thelaachate sumps are pre-fabricated then the supplier must certify that they mnet projectspecifications. The sumps delivered to she siia should be inspected for general compliancewith the project specifications and any damage.

Sumps are the only area of a waste containment system thut will continuously receivetoachate. As such, any defect in the sump may result m a continuous long-term leak. Theseams marfp. at this location are difficult to test due to their short length and tight angles.Destructive samples should be kept to a minimum due to the difficulty of repairs in the vicinityof the sumps.

Pumps

The leachate can be drained by gravity from the waste containment system or It can bepumped out the system using a submersible pump. The pumps used to move leachate aremanufactured for harsh environments and can be powered by electricity or compressed air.Leachate pumps are avsi'able from suppliers who must certify the pumps meat themanufacturer's specifications. The pumps should be inspected when delivered to the site toconfirm that they were not damaged during shipment.

2-10

Installation of the pumps should be done in accordance with tho manufacturer's instructions.All electrical connections, power requirements. Insulation, grounding, and piping should beinstalled snd used as specified by the manufacturer. These items should be inspected duringinstallation to verify that they follow the manufacturer's recommendations. The pump shouldbe tested, using water, to verify that it is working properly.

2.3 Filters

Filter Layers must provide for long-term movement of water through the layer while at the sametime limit tho movement of waste or soil particles across the layer. Too light a filter willquickly clog while too loose a filter will result in an excessive loss of solids through the filter.Biological growth can also impact fitter layer performance and is currently being studied by theEPA. Field verified material properties and installation factors are given in Table 2-3.

Sand/Gravel Filter

A soil filter is used to prevent very fine soil and waste particles from entering into a drain,accumulating, and eventually clogging the drain. Typically, soil filters consist of sand and/orgravel which has been screened to a specified particle size. The sand/grave! filter should havea particle size smaller than the drain particle but larger than the infiltrating particle. The filtermay consist of one layer or several successively gradod layers dupunding upon theperformance objectives of the designer. A soil gradation requirement will be provided for eachsand/gravel filtur layer in the project specifications.

The sand and giavol filter should be laboratory tested to ensure that the grain siiu distributionmeets the project specifications. Individual filter layers are also field tested to ensure that theinstalled filters meet compaction and thickness specifications.

Gcotoxtila Filter

A geotextile filter »s used to prevent very fine soil and waste particles from entering Into adrain, accumulating and eventually clogging the drain. The geotexrile filter is selected by thedesigner based on its opening size and permittivity. Suppliers ol geotextile filters must certifythat the materials meet ths published manufacturer's specifications. Published manufacturerspecifications must also satisfy the specific geotextile specifications for the project.Confomicmcu lusting ol Uiu a, cot excite is recommended for critical f.lter applications (sec fabZa2-3). The fjeotextile arrivus on the site in rolls for installation. The material delivered to thosite should be inspected to ensure compliance with the project specifications and to check fordamage during shipping.

2-11

TASiL 2-3 KL.TER SVSTaj a®4EMT TBSTil««tNS?5erjON

ELEft&NT 1 MAT! RIAt- PROPERTIES/POST CONSTRUCTION CARE ' FIELD TEST

OaeteXSte Pitts'

'Jtoi«f*<ojWfSS8; <- Ifejra! W*or Consent s ASTM DS859- Grata S&e Clst/fbuU)'! MSIJ.HK22

iPoss Corsirus an: Natural fhar <nu&1 ba proftactod i*cmswteoe wato oedrasnte prtci w bulal

• PoSymerPropertea. tei«ir>-, 3snef. Poi/nec fyj», WS?«b%

• WdgSS per equam ycrd• Tenala Slranjfft Ig-ao '»r»lft!

-ACS

. Pu^cfeura Girsngth

w«*S7MD47S1

A3TMM833

BJSTALLAT1OH QUALITY VERIHCATIOtl

- SoS '.Msisr c^fieffrt if specs&ed- Sol donairy H specified- Lift Briskness- Verfy osfiipaKVB «ffer! if demrty spesScd

" Plac<5Ti(ant tonslawalions- Vwify ov«t bp o! ?ucp <U1t) pan te- Verity r*o «dd& or wrsnklss oxiat

- Vwily UBS ol taffiponwy araSiwfigo f nx jIfiKl- Vwily scwi SISCTS

FIELD TEST

ASTM 04959

VisualVjr.LKil

V,»U9J'feud

V%XJB)

The installation of the geotextile should be inspected to verity that panel overlap or sewnseams meet manufacturer's requirements. Additionally, any folds or wrinkles or damage to thepanels must be eliminated and temporary restraint provided if necessary.

2.4

Final cover systems on waste containment systems must be designed to limit the infiltration ofsurface water while at the same time require only limited maintenance for an extended periodof time. Maintenance on such cover systems Is significantly Influenced by the degree oferosion that is allowed. For example, the EPA suggests that erosion be limited to less than 2tons of soil per acre per year. The selection of a final cover system may also be influenced bytho end use of the cover, e.g. park, or climatic conditions, o.g. lack of rain. Field inspectionrequirements for erosion control systems are presented on Table 2>-4.

Surface vegetation may be the most economical erosion control system in those rugions whorerainfall exceeds evapo-transplraiion. The vegetation will typically be a native grass tolatant uflocal climatic conditions. It should also limit spontaneous vegetation by non-duiuable piunts.germinate rapidly, and be compatible with the cap profile. Vegetation having exceptionallyugrjrossivc tap roots should be avoided.

Vegetation is usually bid on a cost par acre basis with a minimum weight of se«d per aerospecified. The seed placement cost should include required soil preparation Stilling, fertilizers,inc.). hydromulcl^ng, and any additional short-torin erosion central rnqu£red until the vegetationis established. Suppliers of fertilizer and seeds must certily that tho fertilizer and seed meetproject specifications. Placement of the seeds should to roadt: in accordance with thesupplier's instructions. "Ihe application rate, time of year, soil prepaiatfon, hydrornulching, andwatering schedule should bu ubsurved and documented.

Topsoil is used to support the growth of tho vegetation on the cap and other locations thatrequire vegetation. The topsoil is usually obtained on site from a stockpile cut from theconstruction area or from a nearby borrow area. Project specifications are typically vagueregarding topsoil properties, but the organic content of the topsoll should tw at least 3 to 5percent, to support plant growth. Reid monitoring is commonly limited to verification of thefinal layer thickness.

2-13

TABLE 2-1

ELEteErfT

VegatelioR

Tapssl

4sph»HCap

Cc^crctQ CJK>

Rf>?sp Cap

MATERIAL PROPSHTJESffOST-CONSTflUCTIOH CASE

* General ProperSis: Scod Bfend. % Wood, cfe.

Post CorwSucfoft. Watering schedule mis* bo nwrte&wd,proteoMrom orcslwi rexi Wrfte prior to Ul growth.

" GcnerstPfOfjenisK (il gi«n si prcjscSspjcjSeaMre)- Ns&ral Wear r;oi!iSar*.• Gfsfn Sto> fjsirtxrt'an-So!?H- Orgario Com - nnd- NuMent Ccfilcnt

Pos! Cwa*ueCcn Piotest *?»!! cu-vxia ofuston «>wV> «'op dsvdoamwil

" Asstwtt MMura -rcctnw- Percent Asphail• Oreun Size Sfeifausor. a( Agorapste Of spsafitd!- CoR53fe8st»l& SreaalhTyffcuJ^ j«<? cwtlikabon by batch pta^

' O»«*8* MWu« FrapcrOas- Msssuw teRiperateo of >w mix• l>9Wt!*n« how loag Iruik Pas soon -en ma• Slump test~o5tforairet.-t<>fentrslr!0dai' n«o''Cf«te

• Meka Sest cylrelsr) tor coro;f«*(ri(in «tfsfsgtti hxsina- Ctrtan faafcsh ie«l fcr csaoh ru;<-ImpeclRsbQ

•asnoraJPropart'T.- Rtx& Sira O^-feutfco

FiELDTEST

Cwlily

ASTM W9KAS7Mt>S2ASTM 04972ASTM Oil

AS~M 3914ASTW Q4SSASTW 3107 •!

ASTMCM3

A3TMC231ASTM 031AS^MCSO

'/teual

ASTM04K

IMSTALLLAT1ON QUALITY VER3FICAT10N

• pssarnnontConjMdoraSIORs• TiBBs o| pta^vnofit por apcca- S<^ pr=p3r.T.i.v-i per specs or *J(id Hjpptter- HydfomukJiing po: apora W saod tuppfar- WMering sef'odula pw specs or ssed auppHer

1 TtaKumni Co-«ld8fa!tas• URThfekness• Water Co.ifc-: itf spcetSe^•DeisllypsOT=d»d)- Surfss- PraporiSSo.-! |if 8pc«fed|

* Rscetfresrt Cwtsoeraticna- Verity ?ite<"..>ii «f asppai song piassd- Verity weal"..'" « ec5«ptet(B Aring pJasaitMni

Oenafr/ e* v.phalt {Seld saal)• &)5ijro«OTti iityo(lQinfeal!ir!o1eiashc!Verify Sarpir^jro ol asphalt (Itflfsg sl»«wi«a

• Racstrom Cc«8icUfations• Ofc6 r«i p ".«r>ar to ensure ihnS jg^re^rta sg nciMparatad fr-CT iinss h fa oonsrale «nU

• Vtsity vltratcn 51! owicrsta to *«n««( votes- Mea«i(« fec.ilian of roratruoon snd a^MS^x\ |cirih• OSeew ap'jicsSor. rate of Wing wnooim a^pisdovsrfieah e- ricieteaatfan

* Placement Ccna<ics t<!rt9• Va*y ID! IK^nnsa• O«ek Sis! <.«rata«to as hcxjcoti dp-rap upwOud• Observe plii. vrcnt of ascrp to oonAm naxltximrt ap hsl il -i"d 'rcfling' ol stsriiM

FIELDTEST

VbwiVbudVisualVisual

VtwtiASTMOWSB;\STMD2S83VisjtJ

VisualWsoslAS7MS380V^uslVisual

Vwjol

'.feualV,ual'/aual

VilMlVisual

Vtws^

Hardened Layers

Hardened covers provide an alternative to vegetative systems in arid regions that lacksufficient natural moisture. Additionally, hardened systems have been used to provide trafficand parking areas after closure of the waste containment facility. Asphalt and concrete

hardened covers are normally limited to slopes less than. 10 decrees.

Asphalt Cap --

An asphalt cap can bo used to protect 3 capping system and provide a potentially usable area

over a waste containment system {e.g. a parking lot). The asphalt cap can replace thevegetation, topsoil, drainage layer, and the biotic layer in the cap. In this application, theasphalt layer must provide the erosion resistance of the vegetatlon/topsoil, the lateral flowcapacity of the drainage layer, and the protection of the blotic layer. "liw porous asphsit layerconsists of an asphalt pavement system similar to that used in roadway construction. The

asphalt supplier must ceitify that the materials meet the project speeifieat'ons. Asphalt

delivered to the site should be inspected for general compliancy with these specifications. The

temperature of the delivered asphalt mix should be measured and tho batch ticket for eachtruck load should he filed for future reference.

During installation, the thickness, temperature, and density of the asphalt should be measured.Additionally, the weather must be monitored to avoid rain or cold tompo/atuj'es that would hurtasphalt placerr.cnt.

Concrete Cap—

Like asphalt, a concrete cap can protect a capping system and provi.-ie a pottnt.ally usablu areaover a waste containment system {e.g. a parking tot). The ccncrete cap replaces l'ievegetation, topsoil, drainage layer and the biotic layer HI th« cap. i;u> concrete layer is similarto that used in roadway construction. Concrete suppliers must cuuify thai the concrete meetsproject specifications.

The concrete delivered to the site should be inspected to determina how long the trucks havebeen on the road and if the concrete can be used. Material properties identified in the. projectspecifications should be variliud (see sample specifications In Table 2-4). Tho foundationbelow the concrete should be Inspected for Ittvelness, strength and the presence of water.

The concrete pour should be observed to verify that the ciggrugato is rot separated from thef.nes in the concrete Tix. and that llvu construction and expansion joints sra properly located.Tho applicjition rate of a curing compound over tho concrete surface should be measured.

2-15

Rip-Rap Cap --

Rip-rap consists of natural stones ranging in size from approximately 1 inch to stones that

weigh hundreds of pounds. Layers of these stones provide a significant impediment to windand water related erosion. Rip-rap layers aro commonly underlain with a geotextilu filter 10limit potential erosion of underlying fines. Field testing is typically limited to verifying that thedelivered rip-rap meets project specifications for particlu size.

The installation should be monitored to verify that thickness of the rip-rap layer meets projectspecifications. Placement of stone or rip-rap should be monitored to ensure that drop holglvtssre limited. An underlying geotextile should be inspected for damage due to stone placement.

When larger stones (> 60 pounds! are placed over a geotextile fabric, drop height stone iscommonly limited to 18 inches (45 cm). Alternately, a soil layer of 6 inches (15 cm) can beplaced over the geotextile to provide a cushion and protect it from damage during rip-rap

placement.

2.5

Waste containment systems and covers frequently include layers that are intended to protectfunctional layers. Outer protective layers include the surface erosion control layers discussedabove (section ?,.4). This section discusses interior protective layers that function even alterthey are buried within the system. While some of the protective functions may be short-termor seasonal, e.g. a protective soil layer pSaaed over a liner to protect it from freezing, mostprotective functions are long-term and are essential to the success of the waste containmentsystem. Table 2-5 presents fifild tists that should be conducted to ensure material integrityand installation quslity ol protective layers.

Biotic Barrier

A Biotic barrier is used in the cap of a waste containment system to prevent small burrowinganimals and plant roots from penstrating the drainage layer or the low permeability barrier. Thebiotic barrier usually consists of a 3 foot (1 m) thick layer of stone or cobbles. Vegetativeintrusion can also be limited by herbicide impregnated geotexiiles that provide timo releaseprotection. Field inspection is typically limited to verifying that the stone particle size and layerthickness meet project specifications.

2-16

TA2i= 2^ HfOTECTMF LAYER E_£M£.VT TESTING/INSPECTION

ELEMENTir Bsrier

> MATERIAL PROPERTIES/POST CONSTRUCTION CARE FIELD TEST' M<?elwiKsil

- Grain Si«! ; AST8.1 0*23

, Post Conssruetb-i; P'eflec* fro-i sto-nvvser £e

INSTALLATION QUALITY VERfflCATKMJpWai

• '.'erify EH thpcknusa j Visosl• Verify apaclfted -soiVgaateicite bsrsanlh ston jViBua!• Observe plac -ent e< slone oro spacs Visoai

SeoteKile * folyrrer Properties DenBfl%', Ueru«r Certifcat-on

Tsss: Pef praiecs- Mass p»r Unit A-aa

sosJ Const-yotio-ir, Pretest from wind dar.age

iacrirnont CoraidsralrcfisVnnty overlap of adjacew raSai- -nirate tbid or vmrMes dicing insiallsaior.

• aiov|cie iamp<bi-«-y jjnchoroge oer spese.

VisuolVisualVaual

Soil Protective Laye'- Nttun* Water Cent*-: 04S69

D422

* P acnmertf ConsideralicnsWn'Rf Comer?n-plac» Cwrsily

ASfTM D*959A9TM WS?3

f'rclscl t*yer f-c-~i surface waffit • V>aual Obscrvai on cf Conpact n Effort iVissjal

A protective layer over the bottom liner, leachate detection layer and the primary loachatecollection layer is required to protect these components from damage during construction andwaste placement. The geotextile protective layer is normally a nonwoven material selectedaccording to its unit weight (ounces/yard*). The heavier tha nonvooven material, the morecushion it provides. Suppliers of geotextile protective layer materials must certify that thegeotextile meats the manufacturer's specifications.

The geotextile arrives on the site In rolls for installation. The material delivered to the siteshould be inspected for genera! compliance with project specifications and damage fromshipping.

SoTI Protective Layer '

A soil protective layer ovur the liner, leachate detfection layer anrf the primary leachatecollection layer Is required to protuct thusc components from damage during waste placementsnd from the extremes In the weather. The soil should be selected for its resistance toerosion, strength, and stability on the side slopes of the waste containment system. Typically,an on-site soil can be used as the protective layer. Tho soil should bo laboratory tested toverify that they meet tho project specifications. Typical soil protective layer specificationconsiderations are given in Table 2-5.

Special attention should be given to the installation of a soil protective layer over ageomembrane liner. Such installations require loss rigorous compaction specifications for thefirst lift to avoid damaging the geomembrane dudng compaction.

2.6 Earthworks

Construction or closure of waste containment systems typically requires construction ofearthen containment structures, such as dikes and faerms, and the development of stableworking benches (surfaces) over weak wastes or contaminated soils. Due to cost restrictions,earth work is usually dona with either on-sito 'or focal soils. In view of the diverse nature ofthis material, close monitoring during construction is often necessary to achieve designconditions. Weak or soft spots in compacted soil are commonly detected by proof-rolling usinga loaded dump truck. Any soil experiencing excessive rutting should be recompacted o'excavated and replaced. Common field tests of earthwork fire shown on Table ?-«.

2-18

TABLE S* EARTHftVOfK ELEMENT 7E3nsO,WSPECT<XS

CLEMENT

Swistura! nt

Sol: Bedding layer

<3eatextila«».»sydSteddrg layts?

MATERIAL PROPfcflTIES.POST COHSTRUC1IOM CARE

* Mffl.har.ca' Pn^psrlUfs'fefiiJ Water CfcnK' itOrsin St7G tXelr^jbt* iMilstu'O LJwtsily ^chntx^shp

• WSe-fcurg Lmitt

Pest Conalrjc'oi PT-AVI lsy«r 1ram trjrfasc «»•«*' cios<«

• Wsdvmea1 Pnaosrtm• ?«Kjral \Vatat CentersGrar, Sao DnlrbutMi

• Pslyiro' p'oparwi

* Mcehan<al H-«peni«i- *V**:?"'. pef sctjr-rs ',«i'.i- Ohs-gtn

• iVn^Vidlf, SBO-WVI

nt 10 TEST

AS7M 04983AS'V 0*22

ASTV D5as7,.lK8ASTM04318

ASTWrx36@ASTVEMaS

"

CwU(i=cs«n

f*fccs-r^A^MEwesaAS~V CWO5

IHSTAALATION QUALITY V£«mCAT10^4

' pac<KT«nl Corusdcmltenr,- Sol- water octitent as cpectiiod

SoS <*?**% a= =p=o^<vrf- LiR thckniyjir. vadS«d

" cement "oraKdqrBStofft• Sail water content as ;p=cffico

• So* dwell/ aa spsofiee- UfS IhdcicaT' wr^^ed

- Vnrfy fr<a 9 1 =

' Placement: CcnaksefalisrM• Vcflfy ovH«Si ft adjoco*-: rolte- EJmnato foW cr wttirWes djrt snslr lohof- Provide tAt cnaiy ichira^a if ec i*w^

VlELDTEST

ASfTM 04839AsTMnasesWajal

ASTMW959AST1 [»KKSVfcuslSu-.wy

'/isual•\/lr, ol1/I81.M!

Structural Fin

A structural fill is designad to support its own weight and that of any overlying systemswithout experiencing excessive deformation. Such fills are typically placed to develop aminimum shear strength or compressibility as assumed in design, laboratory sheaf strength orcompaction tests, made prior to construction, are used to establish acceptablemoisture/density requirements for such fills.

FiSI soils must be inspected at the site to ensure that they are suitable and have low plasticity{i.e., plasticity index <10) and no large stones (<0 inches). Compacted soils should be testedto verify tiiat they achieve the minimum dry density established by the project specifications.

Soil Bedding Layer

A soil bedding layer is used to level tho waste surfaca immediately below the cap. Thebedding layer provides a smooth and stable working surface for the construction of the capand is usually made from an on-Slto soil with good strength properties. Other than proof-rollingand measuring the final grade, little field testing is performed on bedding soils.

Geotextile or Gecmrid Be tiding J.9YffiC

A geotextile or geogrid bedding layer is used to level the waste surface and bridge any voidsimmediately below the cap. Additionally, the bedding layer provides a smooth and stableworking surface for the construction of the cap. The geotextile or fjeogrid must have hightensile strength and ba puncture resistant. Suppliers of goosynthotic beddmg materials mustcertify that the materials supplied meet ;he manufacturer's specifications. The geosynthp.tins,which are delivered to the site in rolls, should be inspected to ensure general compliance withthe project specifications and to check for damage.

The installation Is usually monitored to confirm that tjGotextile or geogrid overlaps meet themanufacturer's specifications. Six (GJ inch (15 cm) overlaps are common. Confo'mancutesting of the geotextiles or geogrkls can be performed as indicated in Table 2 6.

2,7 References

2-1 - U.S. EPA. 1991. Design and Construction of RCRA/CERCl A Final Covers. SeminarPublication EPA 625/4-91/025, Office of Research and Development, Washington,DC 20460.

2-2 - U.S. EPA. 1991. Design, Construction, and Operation of Hazardous and Non-

2-20

Hazardous Waste Surface Impoundments. Technical Resource Document EPAb30/SW-91/054, Office of Research and Development, Washington. DC 204GO.

2-3 - U.S. EPA. 1989. The Fabrication of Polyethylene FML Field Seams. TechnicalGuidance Document EPA 53Q/SW-89/069, Office of Solid Waste and EmergencyResponse, Washington, DC 20460. (Superseded by REF 2-5)

2-4 - U.S. EPA. 1989. Requirements for Hazardous Waste Landfill Design, Construction,and Closure. Seminar Publication EPA 625/4-89/022, Center for EnvironmentalResearch Information, Office of Research and Development, Cincinnati, OH 45268.

2-5 - U.S. EPA. 1991, Inspection Techniques for thu Fabrication of Geomembrnne ReidSeams. Tuchmcai Guidance Document EPA 530/SW-9U051, Risk Reductionfcngineering Laboratory, Cincinnati, Oil 15268.

2-6 - U.S. EPA. 1987. Geosynthetic Design Guidance for Hazardous Waste Landfill Cellsand Surface impoundments. EPA/600-S2-87/097, Hazardous Waste EngineeringResearch Laboratory, Office of Research and Development, Cincinnati, Ol I, 45268.

2-7 - Koerner, R.M., Pesignirtg with Geosvnthetlcs. Prentice-Hall, Englcwood Cliffs, NJ,1990.

2-8 - Standards for Specifying Construction of Airports, Advisory Circular 150/5370-10A, U.S. Department of Transportation, Federal Aviation Administration,Washington, DC, 2/17/89.

2-9 • ACI Manual of Concrete Practice, Part 2, Construction Practices and InspectionPavements, Dat.-oit. Michigan 48219. 1984.

2-10 • Annual Book of ASTM Standards, American Society for Testing and Materials,Philadelphia, PA 19103, 1990.

211 - Elsbtiry, B.R., et al., "Lessons Learned from Compacted Clay Liners," J.Geotechnicai Engineering, ASCE, November 1990, 16^11-1600.

2-12 - U.S. EPA. 1987. Construction Quality Control and Post-Construction PerformanceVerification for Gilson Road Hazardous Waste Site Cutoff Walt. EPA/600/2-87/065.

2-21

SECTION 3.0

Hold Sampling Strategies

Key elements of a waste containment system should be sampled and tested to verify that thematerials meet project specifications and that they are being installed in accordance with thedesign drawings. Sample tests can also be used to monitor the construction process, predicttrends in the quality of the installation, and detect sub-quality construction trends. A field

sampling strategy in its simplest form can be implemented by 'randomly" picking out a halfdozen or so samples for testing, and accepting the area or lot if all the tests fall within thelimits of the project specifications. A "lot" is a clearly defined production unit such as a given

days batch of grout or a clearly identified production run of a geosynthetic product. While thismay bo an appropriate sampling plan In some cases, the risks associated with this plan should

be known before implementing it. If factors such as sample size, sample location, andacceptance criteria are not correctly applied, the test results may not represent the quality ofthe area or lot being tested.

A sampling plan, whether it is implemented in the field or in a manufacturing plant, has severaldistinct parts:

1) Delineation of the sample area:

2) pBtormination of tho number of sarnntes bv one oi the following metftods:a) Following the project specifications;b! Using the Sample Density Method, which specifies a minimum number of tests

per unit length, area or volume;c) Using an Error of Sampling Method, such as ASTM E-1 22;di Using Sequential Sampling;

3) Selection of tho sampie locations by one of ih« following methods:

a) Include every potential sample location -- Census or one-hundred percent{100%} sampling of the area or lot;

b) Select locations using the judgement of the project inspector — JudgmentalSampling;

c) Include every "nth* potential sample location starting with a randomly sotactedstarting location corresponding to a randomly selected number less than "n".(For example, select every 10th location starting with the 9th location, le.locations corresponding to 9, 19, 29, etc.) •- Fixed Increment Sampling;

d) Selecting sample locations completely at random using a random numbergenerator - Strict Random Selection;

ei Subdividing the test area uito logical sub-areas and randomly selecting locationswithin each subarea -- Stratified Random Selection;

3-1

4} Obtaining and testing the samnlss using the appropriate methods;

5) Acceptance or rejection of the area or lor based on either:a) comparison of the sample statistics (mean, variance, etc. of the test values)

with the limits presented in the projuct specifications;b) comparison of the sample statistics with predetermined limits calculated to

keep the construction process In control.

6) Devefonment of a remedial action plan to change the construction process if thequality of the construction declines

7) A cigar method of historical documentation so that all of the original records,including the sample locations, test results, and the analysis of the test results(sample statistics), are available for project certification or future litigation.

3.1 Delineating the Area or Lot Being Tested

The area or lot being tested must be divided into potential test locations that can be ciearfyIdentified at a later time. The test area or lot should therefore be tied to an easily identifiedfixed reference point such as a manhole or the crest of a slope (see Figure 3 la). Distancefrom the fixed location to the sample can bo measured slang a linear axis or using a pair ofcoordinate axes. For most sample selection schemes it is necessary that a numbering systembe used to reference the potential sample locations or items. For example, samples from ageomembrane seam arc referenced by measuring distance along the seam. Destructive testingof pipe, however may require samples of 3 specific length (e.0- 3-fefit). Tho pipe can bemarked off in 3-foot intervals with ear.h segment given a number that identifies the sample(see Figure 3-1 b). In delineating an area for sampling, a coordinate pair of axes must be usuUinstead of a single axis. The samplu locations can be delineated by distance measurementsalong both axes, or by assigning numbers to sampto a-'cas corresponding to subdivisions of anoverall grid (see Figure 3-1c). Each sample should be marked or tagged to provide cleardocumentation of the test location.

3.2 Determining the Number of Samplu Locations

The number of sample, locations required for testing a given element is normally included in theproject specifications. Sometimes, specifications for sampifi locations dutarmine the number ol

3-2

FIXED OSlGfN FOR-MEASUREMENT Of

SEAM IN GEOTEXTILEMANHOLE

FfXED OR?GIN FORMEASUREMENT 0? THEPIPE

OUTFALL

3-1-a.) EXAMPLES OF FIXED ORIGINS

SCAW IN GCOMEMBSANt

.—. ... . _ | .._. i ( . j j j _,

0 1 2 3 * 5 6 7 8 9 !0 1 1 1 2MEASUREMENT IK FEET

FiXEDC8KKN

L._ r - SAMPLE OF PIP£

DEUHEATICH O? ?:PE SAMPLE LOCATCNSUSSNG 3 FOOT W0€

3-1-b.) EXAMPLES OF LINEAR SAMPLE MEASUREMENT

ws |u,ft-i it.

~i i i i r -j-"-p—•} | i p*5 1C 1!> 2Q 75 30 35 40 45 SO 55

MEASUREMENT IK FEET

SAH4M.I AREA 9.6

_ _L_LU_U_.2-|

rT~T~"T T~~i t i i ' i t "1 Z J 4 5 5 7 S 9 5 0 - 1DELINEATION OF SAMPLE LOCATIONS

USING 5 FOOT SQUARE SAMPLE ASLEAS

5-' c.) EXAMPLES 0" AREA SAMPLE MEASJREMENT

FIGURE 3-1 EXAMPLES OF DELINEATION AND MEASUREMENT

OF LOT OR AREA BEING SAMPLED

3-3

samples, e.g. every 't' section of a seam in a flexible membrane liner must bu lasted. Apartfrom these instances, three methods — sample density, error of sampling, sequential sampling -- are used to determine the number of samples to be tested.

Sample Density Method

The sample density method specifies the mlOltrMB number of sample locations per unit ofmeasure (sample density) for a given element. This method is popular with regulatory agenciessince it is readily applied and verified. It can be applied to linear systems (e.g. seams), surfaceareas (e.g. geomembranes). and volumes (e.g. grout). Table 3-1 shows typical samplingdensities for all three of these element types, Note that sampling densities can bt>. given Ineither area or volume units. For example, clay liner testing can be specified as number oftests/acre fill or number of tests/volume of fill. Common sampling densities for wastecontainment elements are presented In Appendix A.

Error of .Sampling J

The error of sampling method is used to determine the number of test samples required torepresent the quality of the entire areo or lot with' an acceptable sampling error. The samplingerror is defined as the maximum allowables difference between the sample estimate of lot orarea quality and the measure of quality that would be determined by 100% sampling.Calculation o' the number of tests needed to estimate Che proportion of defective areas ol asoil liner, using ASTVl FM7?,, is shown in Figure .3-2. *

The number of sarr.pius required by ASTM C-1 22 is a function of lha imp.irranne of thebeing tested (K). the allowable difference between actual and indicated quality (E). arid anestimate ol the actual number of defects in The a'ea-ot lot (Pi. C<il:;u»Kiu<::> !M o n/r-.in unnumber of tests for a clay liner are shown oh figure 3-2. Since a clay liner is a very critics'element of a waste containment system, the K factor is 3. Tha allowable tliflererscH betweenthe actual quality and the sample estimate of quality is sat at S percent or P = 0.05. Anestimate of the actual number of defective tests in a given lot or area (P> requires some priorknowledge of similar applications which may require reviewing past records. This estimate canbe adjusted as the project progresses to reflect actual site experience.

A minimum of 1 71 tests must be performed on the example clay liner to satisfy our assumedrequirements. Note that AS1M £-122 does not incorporate the sire of area of Int. In the caseof a two foot thick clay linsr. the test density fyd'/test) is a function ol the Si/e of tho liner asshown in Figure 3-2, Thus thu 171 tests reflect approximately 1 test per 300 cubic yards nfclay far a 15 acre site and 1 test per 500 cubic yards for a 25 acre site. Common samplingdensities for clay liners range from 1 test per 250 to 500 cubrc yards of clay (see Appendix A),

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TABLE 3-1 EXAMPLES • SAMPLE DENSITY METHOD

ELEMENT/SYSTEM TYPE PARAMETER

Geomembranc/Llnear DT Seam Test

Clay Liner/Area Density

Clay Liner/Volume Density

TEST METHOD

ASTOD413ASTMD3083

ASTMD2922or

ASTMD2Q37

ASTMD2922or

ASTlvlD2937

MINIMUMIE33M1 FREQUENCY*

1 /500 Ft. Seam

b/acre/G" lift

1/500 YD3

Grout/Volume Slump ASTMC143 1 ,'500 YD3

Fof laodlili linurs - the minimum testing frequency may be decreased (e.g. 1/1000 ft olssam) for caps or (arnrioiary applications as required.

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REFERENCE: ASTM E-122 ERROR OF SAMPLING METHOD

DEFINE NUMBER OF TESTS (n) TABLE - k FACTOR

n ** (K/Ef P(1-P)

WERE P =1 ESTIMATE OF THE TUCTICN CFOEFSCT1\€ TESTS Pm UNIT

£ = MAXIMUM ALLOWABLE DIFFERENCEBETWEEN THE ESTIMATES OF CijAUTYFROM n SAMPLES M® ;QQXTESTSNG

K » A .-ACTOS CORRES^ONRKC TO THEPRC8AB)Urr THAT THE SM4PUNGERROR WJL EXCEED E. (SEET/^LE)

K PROBAaiUTY CF tMPORTANTCC OF

3 C-CO3(.T (n SOOQ)

2.58 0.0-. (1O in 'COO)

2 0,045(45 In 5000)

I..16 0,05 (S To 100)

1.?J. 0.10 0a 'n iOC)

?y csmcw,raci

NOT CflrnCAL

EXAMPLE APPLiCATION

DEFINE NUMBER OF MCimiRST/DRMSITY TESTS ~GR SO'i, i.lNFR

ASSUMPTIONS:

p „ 5% =05 OUT OF 160 TESTS ARE DEFECTIVE

E = 5% =B=> ALLOWABLE DIFFERENCE « ±5%|< = 3 ==> VERY CRITICAL ELEMENT

SCO

n = (3/0.05/0.05 (1-0.05) = !71 TESTS "g

.35 300

NOTE: ACTUAL TEST OENSlTY IS A FUNCTIONOF VOLUME OF SOIL UNER, a.g.15 ACRE SITE WITH 2 ft UNER

TEST DENSITY « ^8642 YD/'171 = 2'IS YD/'TEST

onn20°

5 :Q -5 20 25ACRES

RGURE 3-2 NUMBER OF SAMPLES-ERROR OF SAMPLING METHOD

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Sequential Sampling

The Sequential Sampling scheme is designed to minimise the required sample number whun thi_>quality of the area r>r lot is either exceptionally good or very poor. Most sampling plans require

a fixed sample size {determined prior to construction) which is independent of the resultsobserved at the first sample locations. Sequential sampling uses the results of the tests asthey are conducted to adjust the number of samples required and the acceptance criteria.Areas or lots with high or low quality require a smaller number of tests than those with

marginal quality. Note that the sequential sampling method defines both the number of

samples and the. ascoatarico crituriu which dupuad on the results of earlier sample test results.

A sequential sampling plan requires that after each sample location, or small group of locations,Is evaluated thai one of three decisions Is made about the test area or lot from which thesample(s) was(were) token:

• The test area is accepted• The test area is rejected• The evidence Is not sufficient to makt; a decision without an

unacceptable risk of error

These three decisions are illustrated by the three regions on the chad shown on Figure; 3 3. Ifthe last decision is marie, more sampls locations must be selected and evaluated. This processis continued until the test srea is accepted or rejected or a limit on the number of test isreached e.g. all. Typically a graph as shown in Figure 3-3 is used to implement this samplingscheme.

Four variables must he determined to implement this sampling p'on. These vaiiob'es include:

P., •» acceptable proportion r>f defective sample locations ma test area;

Pj = unacceptable propu.'Uun of cluluctivu sample locationsin a test area;

iJ «• ths probability of rejecting an acceptable test area. I thequality of the test area is Acceptable but the sampleresults indicate that it is unacceptable);

fl = the probability of accepting an unacceptable* itist area.{the quality of the test area is unacceptable bet thesample results indicate that it is acceptable).

These values, which are selected by the person designing the sampling plan, should reflect thedesired precision of the. test results, the importance of the tested element and the cose anddelays due to sampling and testing. Tho consequences of a wrong decision are key

REFERENCES (6,7,8)

DEFINE ACCEPTANCE CRITERIA

P, » % D£fECTS ACCEPTABLE

PI = % DEFECTS UNACCEPTABLE

S = % PROBABILITY OF REJECTING A "HSTA«EA WITH QIJAUT^ HEATER THAN f?

g * !? PROBASfUTY OF ^OfPTING A TESTAREA V/1T1I QUALITY JiSS THAN i>

iNE ACCEPTANCE/REJECTION CHART

A = ^((i/RXOOO-^/aOO--:?)))

h, = iog((100-a)/j8)/A

h* = log((lOO-/S)/5)/A

S = lcg((lQO-=0/(10Q-F2))/A » SLOPE

EXAMPLE APPLICATION

DEFINE ACCEPT.i'*C£ CHJ^CAL ^0=? ORYDENSIT" Cr STRJCTXJSAL RLL.

h,_L

RE-ECT THE TEST AREA

TOTAL NUM9ER OF TESTS

5=10

ASSUVPT10KS:

|s=5 (5=10

/• - i-jcK'cAKJici

K = log((100-10)/20)/A - 2.0

N - log((irX!-20}/10}/\ = 2.8?

S = !(x-<(OnO-5)/(100-lO))/A = 0.07

.'. MINIW-M CF iO TESTS

-20

FIGURE 3-3 NUMBER OP SAMPLES-SEQUENTIAL SAMPLING

3-8

consideration when selecting those values or limits. If the constraints are too rigid, therequired sample size (number) will be so large that the associated costs are prohibitive. Hence

it is necessary to tradeoff up-front costs for sampling, the costs of rtrdoing a lot rejected inerror (the sample gave misleading results indicating a good lot was defective), and tho costs of

failing to detect a faulty lot until much time has passed. If the cost of rejecting good materialIs high then <T should be small. If on the other hand acceptance of inferior material is high, the

typical situation fur environmental materials, then R should he small.

An application of sequential sampling acceptance criteria to structural fill is given in Figure 3-3.

Structural fill Is an element that, white important. Is less critical to the success of a wastecontainment system than such elements as clay or geomombrane barriers. Hence in this

situation the decision maker may be wNNng to tolerate more defects (larger P, and Pj) and belass concerned about incorrect decisions (larger <J and B). If so, the number ol required

samples will be less than for materials which are more critical to tha success of a till. Theimportance of an element is reflected in the scSecuon ul the four variables required to define

the acceptance chart.

fcxample (Figure 3-3)

The percent defects in an unacceptable fill (P2) is assumed to bo 10%. This is twice as

tolerant as the criteria used in the previous example for clay liner material. The percent defectsin an acceptable area {P,) was selected as the mean of the acceptance range (< 10%).Purccnt probabilities for accepting a defective test area (B) or rejecting an acceptable test area(6) are selected in the example to reflect the lower iinporiancu of the structural fill. For acritical element, S will be smaller and 6 could be larger since it is more important that adefective critical element not be accepter).

A msnimum of 40 density lasts rnust bu purformod lo gtjt acceptance of the structural fill usingthe sequential sampling chart developed above. II no dufuctiva density tests occur in theseforty (40) tests, then the structural fill is accepted. If two (2) or more defective locations arefound the Sot is rejected. If one 11} defective location is found then additional sample locationsmust bo sulectud and evaluated. Testing must continue until the chart indicates that the lot isacceptable or must be rejotited.

3.3 Selection of Sample Locations

Field samplir-g t>iroto.jics *ur scleci'i'iy j iinylc sa'p.piu location may follow several samplelocation criteria. This is paniculoriy true for critical elements such as the seams oJgoornembranti liners. Hia protocol Sor locating test sarnplas on seams includes all of thefollowing criteria:

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For Non-Destructive Testing

For Destructive Testing

100% Testing

1 per 500 Feet (Incremental)JudgmentalMinimum 1 per seam (Stratified)

Thus the sample location strategics presented in this section may be combined for a givenelement.

In theory, determining tho true quality of a product would require sampling the gfl|l£§ product --which is known as 100 percent sampling. Although nan-destructive testing methods can beused to sample and test o5l of the product or test area, this requires a significant investment oftime and capital. For these reasons, a 100% sampling plan is used on!y to test the mostcritical elements in waste containment structures; the seams in the synthetic liners used inlandfills, waste piles and waste ponds. Because a defect in the seam will allow a release ofwaste, 100% testing is considered necessary.

Since a 100% sampling plan is rigorous, the sampling and testing program should be designedto minimize inspector fatigue. A sufficient number of testing crew breaks arid shift changesshould be used to avoid errors in the sampling and testing program.

The 100% Sampling Plan:

Step 1 Develop a means o? delineation and measurement that can be UKRCJ to rithe sample locations over the entire test area. Since this a 1tM% sampling plan.the delineation will not be used for sample selection but will serve to ensure thatall locations are tested snd to locate any defective locations.

Step 2 Test the entire area or lot using a non-destructive test method (see Appendix A).Careful documentation must be made of the starting and stopping locations,material batch numbers, installation crews, and other variables that may affect thetesting results. Compare the results of testing to the project specifications. Allareas that do not meet the project specifications will be rejected and removed orrepaired (and re-tested).

Example -- Installation of a 60-mi! HPDE goo membrane liner. The 100% Sampling Plan wouldbe implemented as follows;

3-10