1、Designation: D 6523 00 (Reapproved 2005)Standard Guide forEvaluation and Selection of Alternative Daily Covers (ADCs)for Sanitary Landfills1This standard is issued under the fixed designation D 6523; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide is intended to assist specifiers and end usersin assessing the different opti
3、ons available for sanitary landfilldaily cover materials described as alternative (non-soil) dailycovers (ADCs). Traditional daily cover consists of at least 6 in.of soil spread over the working faces of sanitary landfills.Alternative systems are attractive to landfill operations in orderto conserve
4、 landfill disposal space, among other reasons.1.2 This guide assists in understanding different perfor-mance features of broad classifications of ADCs, and deter-mining the extent and degree to which different ADCs are ableto “control disease vectors, fires, odors, blowing litter, andscavenging, wit
5、hout presenting a threat to human health andthe environment,” as intended by United States EnvironmentalProtection Agency (USEPA) regulations.1.3 This guide is not intended to provide cost informationregarding the various ADCs as a standard guide, it does notdictate a protocol for the practice and t
6、esting of ADCs, butrather provides valuable information, guidance, and recom-mendations to interested parties concerning the many optionsavailable.2. Referenced Documents2.1 ASTM Standards:2D 4982 Test Methods for Flammability Potential ScreeningAnalysis of WasteE96 Test Methods for Water Vapor Tran
7、smission of Mate-rials2.2 Other Standards3Solid Waste Disposal Facility Criteria, USEPA, TechnicalManual EPA 530-R-93-017, Cover Material Require-ments, 40 CFR 258 21, Nov 1993“The Use of Alternative Materials for Daily Cover atMunicipal Solid Waste Landfills” EPA 600/R-93/172 PB92-227197 July 1993A
8、lternative Daily Cover Regulations, California Environ-mental Protection Agency, Title 27, Division 2, Subdivi-sion 1, Chapter 3, Subchapter 4, Article 2, Section 20680CIWMB Daily Cover and Section 20690 CIWMB Alter-native Daily Cover3. Terminology3.1 alternative daily cover, nan alternative to the
9、tradi-tional 6-in. (15-cm) soil cover required by the USEPA forlandfill working faces to “control disease vectors, fires, odors,blowing litter, and scavenging, without presenting a threat tohuman health and the environment.”3.2 foam, na synthetic material sprayed and combinedwith air to form closed-
10、cell air pockets.3.3 geosynthetic, na planar product manufactured frompolymeric material used with soil, rock, earth, or other geo-technical engineering related material as an integral part of aman-made project, structure, or system.3.4 indigenous, adjnative to a particular region.3.5 leachate, ncon
11、taminated water resulting from thecombination of waste with precipitation.3.6 nonreusable, adjin geosynthetics, a fabric or filmintended to be placed once and then disposed of, discarded, orleft in place.3.7 reusable, adjin geosynthetics, a fabric or membranematerial intended to be retrieved and ins
12、talled more than onceto perform the cover function.3.8 sanitary landfill, na regulated disposal site for thedeposition of commercial and household wastes.3.9 working face, nthe area of a landfill in which waste isactively being deposited.4. Significance and Use4.1 This guide provides information whi
13、ch the regulator/permit officials, engineers, waste disposal operators, and otherswill find helpful to (1) understand and distinguish between the1This guide is under the jurisdiction ofASTM Committee D35 on Geosyntheticsand is the direct responsibility of Subcommittee D35.03 on Permeability andFiltr
14、ation.Current edition approved June 1, 2005. Published December 2005. Originallyapproved in 2000. Last previous edition approved in 2000 as D 652300.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStanda
15、rds volume information, refer to the standards Document Summary page onthe ASTM website.3Available from the Superintendent of Documents, US Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United Stat
16、es.many choices available; (2) understand the performance fea-ture considerations for living up to EPA regulations for landfilldaily covers, and (3) understand the various requirements anddifferences for putting these covers into practice at landfills.5. Classifications of ADCs5.1 FoamsFoam ADCs are
17、 applied to the working face ofsanitary landfills using foam generation and application equip-ment specifically designed for that particular foam. Bothhardening and non-hardening foams are currently available.These foam layers are effectively broken-up by the placementof additional wastes on the nex
18、t operating day, and thereforedoes not interfere with fluid movement.5.2 Spray-On SlurriesMost slurries are paper-based. Thepaper-based slurry ADCs are applied to the working face ofsanitary landfills using standard hydro-seeding equipment.Certain types of slurries may require some modification of t
19、hehydro-seeding equipment. The slurries are allowed to harden toform a crust or shell over the working face. This covering isalso broken-up by the placement of additional wastes on thenext operating day.5.3 Geosynthetics:5.3.1 ReusableReusable geosynthetic ADCs consist ofvarious types of fabric or p
20、lastic membranes that have eitherbeen developed or adapted for use as a daily cover material.Panels fabricated from these materials are placed over theworking face at the end of the day, and retrieved prior to thestart of the next operating day. Some landfills use specialmechanized equipment to faci
21、litate the placement and retrievalof panels.5.3.2 NonreusableNonreusable geosynthetic ADCs con-sist of less durable disposable films or fabrics, intended to beleft in place without retrieval. Special equipment also exists tofacilitate the placement and anchoring of these materials tocover the workin
22、g face of landfills. The cover may containpro-degradant additives to accelerate degradation within thewaste to cease the interception of fluids.5.4 Indigenous MaterialsIndigenous ADCs consist ofvarious types of locally available waste products for disposal(for example, sludges, ash, shredded tires,
23、shredded greenwaste, pulverized construction and demolition debris, automo-bile recycling fluff, foundry sand, and so forth) placed onto theworking face of landfills in a manner similar to soil cover. Theyoften require physical or chemical modification for consistencyand workability, and evaluation
24、for the presence of potentiallyhazardous constituents. Processed indigenous materials such astreated sludges and asphalt-stabilized soils are available frommanufacturers who are able to provide such products withconsistent properties. Manufacturers should have the necessarysupporting data available
25、for review. Unprocessed ADCs canvary significantly with respect to physical and chemical char-acteristics and composition, depending on the particularsource. In addition, suitability and acceptability are dependenton site-specific climatic and operational conditions and regu-latory requirements. Bec
26、ause of the wide variety of processedand unprocessed indigenous materials, only key factors andconsiderations related to the use and performance of thesematerials can hereby be presented.6. Features and Considerations6.1 SummarySee discussion for clarification.TABLE ContinuedFeature/Consideration Fo
27、ams Spray-on Slurries Reusable Geosynthetics Nonreusable Geosynthetics Indigenous MaterialsMethods of Application Self propelled or towedequipment with manifolddistribution, or truckmounted with handheldhoseTruck mounted or trailermounted hydro-seedingequipment w/spray towerand nozzle.Manually, towe
28、d withcompactors, or spreadw/specialty wide paneldeployment equipmentManually, or spreadw/specialty unwinder at-tached to dozer/compactorand placing ballast soil toanchorMost often spread withdozers as with traditionallydaily cover. Varied.Post-Application Require-mentsa) Equipment Clean-up/Maintena
29、nceHigh Low Low if placedw/equipmentLow if placedw/equipmentLowb) Remove Cover? No No Yes No NoApplication in DifferentClimatesa) RainSome not recommendedfor use during rain.Others can withstanddrizzle/light rainfall orlight to moderate rainfall.Can apply in light rain.Once cured, canwithstand moder
30、ate toheavy rainfall.Some have no constraintswhile others can absorbwater, increasing panelweightRain tends to help anchorcoverGenerally OK, but sludgeand mulch are unsuitablyapplied in rain due to ex-cessive run-offb) Wind Can apply in 2040 mphwinds. Adheres toworking face.Can generally apply inwin
31、ds up to 45 mphDepends on ballastmechanism. High windscan pick and destroy.Increase ballast material.Small panels, disposablenature reduce impact ofwind damageMost forms OK but yardwaste and auto fluff areexcessively effectedc) Freezing Temp/Snow Can apply under freezingconditions, but equipmentmust
32、 be protected. Someequipment has freeze pro-tection system.Can apply in freezingtemperatures or snowSome have no constraints.In others, if moisture hasbeen absorbed, panelscan freeze, making theirplacement and retrievalmore difficult.Shift to different ballastmaterial w/no moisturecontent (eg crushe
33、dglass instead of sand)Generally no Constraints.Sludge and mulch havesome difficulty in snowD 6523 00 (2005)2TABLE ContinuedFeature/Consideration Foams Spray-on Slurries Reusable Geosynthetics Nonreusable Geosynthetics Indigenous Materialsd) Hot Weather No constraints No constraints No constraints N
34、o constraints Dust generation in manycases (i.e. unprocessedmaterials)Disease Vector Control?(Access by insects,vermin, pathogencontact.)Discourages insects andbirds from landing;rodents from diggingIf proper thickness, dis-courages insects andbirds from landing;rodents from diggingCan completely co
35、verwaste so as not to attract;Careful for pathogens inhuman rehandlingCan completely cover wasteso as not to attractMust be applied at suffi-cient thicknessFire Controla) Combustible?a) Most no, some yes a)Some no, some yes.Materials should betested per ASTM D 4982.a) Yes a) Yes a) Some yes, others
36、nob) Barrier to air/gasmovement?Low Medium High High Low to HighOdor and Air EmissionControl?Uniform coverage is key. Uniform coverage of suffi-cient thickness is key.Material can be testedby ASTM E96permeationTrap odors and otheremissions while in place;release odors and otheremissions when removed
37、;can be tested by ASTME96permeationTrap odors and otheremissions; can be testedby ASTM E96permeationDependent on thickness ofapplication and compac-tion. Dredged materialscan themselves be odor-ous.Dust Control? Yes Yes Yes Yes Many unprocessedmaterials generate dustBlowing Litter Control? Yes Yes Y
38、es Yes Auto fluff among othersunprocessed materials cangenerate litterWater Infiltration Control(sheds rainwater)Certain foams can shedwater during moderaterains, once cured.Hardening slurries shedwater.Shed rainwater very effec-tively when in place;allows infiltration whenremovedShed rainwater effe
39、ctivelyfor several layers of coverMany processed materialscan shed water once com-pacted. Others are toopermeable to shed muchwater.Landfill leachate and gasmigration interference?No interference. No interference. No interference; unlessleft or buried in place.No interference with de-gradable materi
40、al(containing aprodegradant); willinterfere if non-degradablefilmAsh-based wastes,dredged soils, clayey soilsand cementitious foundryproducts can all createintervening layersLife expectancy Varies according to typeof foam. Some last 15-20Hrs. while others arefrom 3-7 days.Some last up to 14 days Som
41、e are 20-30 days,while others are 10-12monthsVaries from days tomonths depending onadditives and conditionsVaries. Many processedmaterials will last indefi-nitely.6.2 Discussion:6.2.1 Methods of Application:6.2.1.1 Manifold-equipped units apply foam as equipmenttraverses the working face. Self-prope
42、lled units with manifoldapplicator applies foam as the unit backs down the workingface. Handheld hose-equipped units apply foam as the crewwalks next to or across the working face, or both.6.2.1.2 Most slurries use truck-mounted or trailer-mountedstandard hydro-seeding equipment with little or no mo
43、difica-tion. It is applied through the spray tower located on theplatform of the hydro-seeding equipment using appropriatenozzles. The use of a hand-held hose may be suitable forcertain applications. In at least one case, a specially designedstorage unit and mobile applicator is required by the manu
44、fac-turer. Care must be taken to avoid skimping on the thickness ofapplication.6.2.1.3 At some sites, ancillary equipment (for example,tow bar, lifting bar, reel, or rollers) are used to facilitateplacement of geosynthetic panels (both reusable and nonreus-able) and reduce wear and tear. Tires, sand
45、bags, or ballast soilare placed along the edges to anchor the panels.6.2.1.4 The preparation of the working face prior to place-ment of a geosynthetic panel and the care taken in placementof the panel can have a significant impact on the effective lifeof a panel. Consequently, operators should ensur
46、e that theworking face is properly compacted to provide a smoothsurface, and that protruding objects which could damagepanels are eliminated. In addition, during placement of panels,measures should be taken to prevent unnecessary stress on thematerial and minimize snagging while dragging the panelac
47、ross the working face.D 6523 00 (2005)36.2.1.5 Most indigenous materials may be spread and com-pacted in the same manner as traditional sands and gravels.Dozers and front-end loaders are usually used to spread thematerial. Compaction can be accomplished with single-drumrollers, dozer tracks, or load
48、er tires, or combination thereof.6.2.2 Post-Application Requirements:6.2.2.1 When equipment is used to apply ADCs there isclean-up and maintenance. Cleanup often takes place by hosingwith water or compressed air, or both.6.2.2.2 Many ADCs have no other post-application require-ments but are simply b
49、roken up by the placement of wastes onsubsequent days.6.2.2.3 Reusable geosynthetic panels are normally removedfrom the working face prior to the start of the next operatingday. Hence, the necessary personnel and equipment have to beavailable, and sufficient time allowed, for this activity to beperformed prior to the arrival and disposal of waste at theworking face. This may require modification of the workschedule for site personnel. Furthermore, depending on theseason of the year and operating hours at the site, panelretrieval may have to be performed while it is s
