Hazardous Waste Management HierarchyHazardous Waste Management Hierarchy

A controlled site for disposal of wastes on

land, run in accordance with safety and

environmental requirements laid down by a

regulatory authority

SECURED LANDFILL

WASTES ARE PLACED PERMANENTLY IN SECURED MANNER

WASTE IS ENCAPSULATED FROM THE ENVIRONMENT BY IMPERMEABLE BARRIERS/ LINERS

LEACHATE IS COLLECTED, REMOVED & TREATED THROUGHOUT ITS LIFE.

A FACILITY WHERE

All hazardous waste treatment options

result in residues and One of the safer

methods for disposal of them

Best techno-economic option for some

wastes.

WHY LANDFILL ?

SECURED LANDFILL FACILITY

• Last Option

• Primarily Containment of contaminants

ATTENUATE & DISPERSE:

Sites where leachate and waste is allowed to

escape into the environment at a controlled rate.

Pollution is reduced by degradation and attenuation

within the landfills and by dilution of the leachate in

the aquifer

TYPES OF LANDFILL

Containment : Sites are aimed at isolating wastes

and leachate from the surrounding environment for a

considerable time.

Archival : Sites are specifically engineered to

contain wastes indefinitely, but also to permit later

identification and retrieval.

METHODS OF LANDFILLMETHODS OF LANDFILL

Co-disposal : Disposal with M.S.W or similar wastes to take advantage of attenuation processes occuring in such wastes; Critical assessment for compatibility

Mono-disposal: Disposal of wastes having same general physical and chemical form

Multi-disposal: Disposal of chemically different wastes in the same site

Barrier No: 1

Degradation or fixation of pollutants in the waste prior to disposal

Barrier No: 2

Suited location of the landfill site with regard to the geological/ hydro-geological situation of the area

Barrier No: 3

Leachate collection and treatment system

MULTI-BARRIER SYSTEM FOR SLF DESIGN

Barrier No: 4 : Bottom Liner System

Interface between waste body &

subsoil hinders leachate percolation.

Barrier No: 5 Cover Liner System

Avoids penetration of surface and

rain water into waste body avoiding

formation of leachate

Barrier No: 6 Proper operation and maintenance of

SLF

Barrier No: 7 Post Closure measures & Repairability of barriers

BASIC COMPONENTS OF LANDFILL

• Impermeable Liner System on the base and side

• Top cover

• Leachate collection, removal and treatment

scheme

• Surface Water Control Systems

• Other site infrastructure

LandfillLandfill

Why the Liner is required ?Why the Liner is required ?

Isolate the waste body from the environment

Contain the toxic leachate within landfill

Prevent contamination of Land and Groundwater

Avoid remediation in future

Which liner systems are Which liner systems are available?available?

MineralicGeo-membraneComposite (Mineralic + Geo-membrane)Geo-synthetic Clay/ Bentonite MatsBituminous MembraneAsphalt Concrete Liner

BOTTOM LINER • Prevent migration of wastes or ‘by-products’ out of the

landfill into subsoil, ground or surface water

• Should have chemical properties, sufficient strength and

thickness to prevent failure due to :

- Pressure gradients

- Physical contact with the waste or leachate

- Climatic conditions

- Stress of installation and

- Stress of daily operation

TYPICAL BOTTOM LINER COMBINATIONS

CLAY LINER ONLY

ASPHALTIC CONCRETE LINER

COMPOSITE LINERS

ONE CLAY LINER & ONE FLEXIBLE MEMBRANE LINER

ONE CLAY LINER & TWO FLEXIBLE MEMBRANE LINERS

Compacted clay/ compacted amended soilthickness >= 45 cm, k<=10-7 cm/s

Waste Body

Leachate collection layerthickness> = 30 cm., k>=10-2 cm/s

Sub soil

HDPE Geomembranethickness> = 1.5 mm or more.

Single Composite liner system (As per CPCB)

Total Thickness # 45 - 60 cm

DOUBLE COMPOSITE LINER (AS PER CPCB GUIDELINE)

ASPHALTIC CONCRETE LINERASPHALTIC CONCRETE LINER

2 BASE LAYERS

3 SEAL LAYERS

FOUNDATION LAYER

WASTE BODY

USEPA SPECIFICATION FOR BOTTOM LINERS

Three type of liners are specified by USEPA

• Flexible Membrane Liners (FMLs)

• Compacted Clay Liners

• Composite Clay Liners (FML + Compacted

Low permeability soil liners)

MATERIALS FOR FMLsMATERIALS FOR FMLs

Chlorosulfonated PolyethyleneLinear LDPE / Very LDPEPolypropyleneEthylene Inter polymer alloyNeoprenePoly Vinyl ChlorideThermoplastic elastomersHDPE

• Chemical compatability with waste leachate

• Ageing and durability

• Stress and strain characteristics

• Ease of installation

• Water permeation

Key factors considered for selection of FML

CPCB Specification for Geomembrane Liner Special Physical and Mechanical Requirements:

1. Performance under tensile load

2. Tear Resistance

3. Puncture Resistance

Requirements with respect to Combined Physical and Chemical Attack

1. Stress Crack Resistance

Specifications of HDPE Geomembrane (thickness 1.5 mm or more)

Tensile Strength at yield = > 18 kN/m.

Tensile Strength at break = > 30 kN/m.

Tear Resistance = > 150 N

Puncture Resistance = > 250 N

CPCB Specification for Geomembrane Liner

CLAY LINER –USEPA SPECIFICATIONThickness of compacted clay bottom liner = 3 feet

Permeability of soil liners < 1 x 10-7 cm/sec

To achieve this, following characteristics of soil should be met.

• Soil should have at-least 20% fines i.e. fine silt and clay sized particles

• Plasticity Index (PI) > 1% (soils with PI higher than 30 to 40% are sticky and difficult to work within the field)

• Coarse fragments should be screened to no more than about 10% gravel size particle.

• No soil particles or chunks of rock larger than 1 – 2 inches in diameter.

• On-site soils can be blended with imported clay

minerals.

(e.g on-site sandy soils + imported sodium bentonite)

• Calcium bentonite, lime, cement, clay soil from nearby

or other areas ,etc are also used.

• Clay soil is likely to form chunks and difficult and hence

easier to blend on-site sandy soils with dry bentonite

powder.

BLENDED SOILS –USEPA SPECIFICATION

COVER LINER (AS PERCPCB GUIDELINE)

HDPE Liner

Gravels

Section

A A

Cover Liner

Soil Bund

Storm Water Drain Channel

375 m2

m

2 m

0.7 m0.5

m

2:1

Slope 3%

USEPA GUIDELINES FOR TOP LINERUSEPA GUIDELINES FOR TOP LINER

FLEXIBLE MEMBRANE LINER (MIN. 20 MILS )

COMPACTED SOIL – MIN. 60 CM THK

SOIL DRAINAGE LAYER – MIN. 30 CM THK

VEGETATIVE COVER – MIN. 60 CM THK(UPPER SLOPE : 2 TO 5 %

WASTE BODY

TOP LINER – NPC DESIGNTOP LINER – NPC DESIGN

3 MM THK POLYESTER BASEDMODIFIED BITUMINOUS FELT

25 CM THK COMPACTED SOIL

2 X 25 CM THK WELL COMPACTED SOIL

2 X 25 CM THK MODERATELY COMPACTED SOIL

VEGETATION

WASTE BODY

COMPACTED SUBBASE

75 MM THK P.C.C 1:3:6

MASTIC ASPHALT LAYER 2CM THK

3 MM THK POLYESTER BASEDMODIFIED BITUMINOUS FELT

WASTE BODY

SIDE LINER – NPC DESIGN

LEACHATE COLLECTION & REMOVAL•Drainage Layer

•Granular (Sand or gravel, no fine, 2-5 cm dia particle, min.30 cm thk, min K=1 cm/s)

•Synthetic (nets, mats, geo-textiles)

•Pipes and Appurtenances

•Cushions

LEACHATE TREATMENT

LEACHATE STORAGE & TRANSFER

Epoxy coated RCC Sump with level control submersible pump

SURFACE WATER CONTROL SYSTEMS

RUN-OFF

Collect and control run-off from active and inactive portions of the landfill from 24 hour – 25 year storm

Collect and contain leachate contaminated storm water that accumulates in active fill area

Protect integrity and effectiveness of landfill cover system

RUN-ON

Intercept and divert run-on away from active and closed land fill cells from peak discharge of 25 year storm

Minimise site erosion

GROUND WATER MONITORING

Designed to detect contaminant leakage shortly after its occurrence and before significant contamination of ground water

Hydraulically up-gradient and down-gradient wells

Placed around perimeter of fill area within several hundred feet of SLF

No. of wells- Site specific, depends on Size of SLF, Hydro-geology

Minimum Requirements

1 well in up-gradient (Background)

3 wells in down-gradient

IDENTIFICATION OF WASTES THAT CAN BE LANDFILLED

1.Wastes that will definitely need to be landfilled as no other options are practicable

e.g. Asbestos

2. Wastes that could be safely landfilled without prior treatment

e.g. Bio-degradable wastes – technically possible; Better options often exist.

3.Wastes which could be landfilled after pre-treatment

e.g., Liquid wastes; heavy metal salts.Pre-treatment options can include detoxification, precipitation, solidification as appropriate

4. Wastes that should not be landfilled

e.g., Explosives, Compressed toxic gases, Liquid PCBs for technical reasons

CRITERIA FOR DISPOSAL OF H.W IN SLF

• To be dewatered up to the level of 60 – 70% solids

• Following are not be allowed to dispose of directly in SLF if

waste

- Is a fluid, slurry or paste

- Is delivered under pressure or under vacuum

- Has an obnoxious odour

- Reacts with moisture to generate high heat or

gases

- Is highly inflammable (flash point < 40oC)

- Contains very strong oxidising agents

- Contains volatile substances of significant

toxicity

CRITERIA FOR DISPOSAL OF H.W IN SLF

- Contains > 10 mg/Kg Cyanide in the original sample

- Contains > 10 mg/kg Chromate in the original sample

- Contains > 0.5% (Wt.) Mercury

- Falls below a pH value of 2, if eluated 1/10

- Contains > 10 mg/1 of water soluble Arsenic in a 1/10 eluate

- Contains > 10 mg/1 of water soluble Mercury in a 1/10 eluate

- Contains > 3% solvents free from Halogen

- Contains more than 0.5% Halogenated solvents

- Contains > 0.1% poly-halogenated substances of Significant toxicity

(PCBs)

Criteria for Hazardous Waste Criteria for Hazardous Waste Landfilling in Germany due to Landfilling in Germany due to

“Technical Instructions for HWM” “Technical Instructions for HWM” 19911991

PARAMETER VALUEpH 4 – 13

Conductivity <100,000 S/cm

Total Organic Carbon <200 mg/1

Phenols <100 mg/1

Arsenic <1 mg/1

Lead <2 mg/1

Cadmium <0.5 mg/1

Chromium VI <0.5 mg/1

Copper <10 mg/1

Nickel <2 mg/1

Mercury <0.1 mg/1

Zinc <10 mg/1

Fluoride <50 mg/1

Ammonia <1,000 mg/1

ELUATE QUALITY

PARAMETER VALUE

Chloride <10,000 mg/1

Cyanide <1 mg/1

Sulphate <5,000 mg/1

Nitrite <30 mg/1

AOX <3 mg/1

Water sol. Content <10%

STRENGTH

Transversal Strength (Vane Testing)

>25 kN/m2

Unconfined Compression Test >50 kN/ m2

Axial Deformation >20%

DEGREE OF MINERALISATION OR CONTENT OF ORGANIC MATERIALS

Annealing loss of the dry residue at 550oC

<10 W.%

ELUATE QUALITY

CPCB CRITERIA FOR NON- ACCEPTANCE OF CPCB CRITERIA FOR NON- ACCEPTANCE OF WASTE IN SLFWASTE IN SLF

Bulk or non-containerized liquid hazardous

waste

Slurry type hazardous waste containing free liquid

or waste sludge

Incinerable / compostable waste or any other type

of waste from which energy recovery is feasible

In-compatible wastes not to be placed in same

landfills

CPCB CRITERIA FOR NON-ACCEPTANCE OF CPCB CRITERIA FOR NON-ACCEPTANCE OF WASTE IN SLFWASTE IN SLF

Wastes in-compatible with liner material without

containerisation

Extreme hazardous waste (e.g radioactive waste)

Non-hazardous waste (e.g MSW) not to

deposited in HW Landfills

1 Oxidising mineral acids 1

2 Caustics H 2

3 Aromatic hydrocarbons H,F 3

4 Halogenated organicsH,F, GT

H, GF

4

5 MetalsGF, H,F

H,F 5

6 Toxic metals S S 6

7 Sat. Aliphatic Hydrocarbons H,F 7

8 Phenols and cresols H,F 8

9 Strong oxidising agents H H,F H,F H 9

10 Strong reducing agentsH,F GT

H, GT

GF,

HH,FE

10

11Water and mixtures containing water

H H,E SGF, GT

11

12 Water reactive substances Extremely reactive: do not mix with any chemical or waste material 12

E ExPLOSIVE

F FIRE

GF FLAMMABLE GAS

GT TOXIC GAS

H HEAT GENERATION

S SOLUBILISATION

OF TOXINS

LIST OF INCOMPATIBLE WASTES

CPCB SPECIFIED DESIGN CPCB SPECIFIED DESIGN REQUIREMENTS FOR LINERSREQUIREMENTS FOR LINERS

Stability at base of landfill (in soft soil) & in sides

Strength to withstand construction loads/ vehicle

loads

Permeability and material properties as specified

in guidelines

Compatibility with leachate & waste

Transition filters bt. Waste & leachate collection

layer to prevent clogging of leachate collection layer

CRITERIA FOR HAZ. WASTE LANDFILLSCRITERIA FOR HAZ. WASTE LANDFILLS

CONSTRUCTION & OPERATION CRITERIA

INSPECTION, MONITORING & RECORD

KEEPING CRITERIA

POST-CLOSURE CRITERIA

FINANCIAL ASSURANCE CRITERIA

CONTIGENCY PLAN FOR EMERGENCIES

CRITERIA FOR HAZ. WASTE LANDFILLSCRITERIA FOR HAZ. WASTE LANDFILLS

LOCATIONAL CRITERIA

SITE SELECTION

SITE INVESTIGATION CRITERIA

PLANNING & DESIGN CRITERIA

WASTE ACCEPTANCE CRITERIA

LANDFILL LINER CRITERIA & COVER

CRITERIA

CPCB SPECIFIED DESIGN REQUIREMENTS CPCB SPECIFIED DESIGN REQUIREMENTS FOR LINERSFOR LINERS

Protection layer / transition layer between each

component of liner system may be provided

Between Leachate collection layer & HDPE

With Silt / local earth (15 cm thk) / Geo-textile

Adequate clay additive in amended soils

ASPECTS CONSIDERED IN THE DESIGN OF SLF

Selection of appropriate liner system for SLF

Desired design period of the SLF in years

Type of landfill desired

Pit (cell wise development) / continuous

Depth of hard stratum from G.L.

Total lay out size & total area of the SLF

Nearest G.W.T. reported in monsoon season

Depth of landfill below ground level

Height of stock pile above ground level

Inner side, bottom – longitudinal & transverse slopes

Provision and layout of roads, storm water drain, green

belt, office, security, lab, weigh bridge, Vehicle washing

area, leachate sumps, etc around the SLF

BROAD DESIGN BASIS FOR SECURED LANDFILL FACILITY

Quantity of sludge generated

Evolving specific sludge generation factor (I.e. ton of sludge / ton of product)

Sludge generation for envisaged production in future

Characteristics of sludge generated

Specific gravity of dry solids in sludge

Bulk density of raw sludge

Sludge treatment requirements

Moisture content of sludge Results of Eluation tests Chemical composition of sludge

Moisture content, density & other characteristics of sludge after treatment

SITE CRITERIA

• Topography of the site area

• Geological / Hydro-geological situation of the site

(characteristics of the subsoil, presence of aquifers layers, ground

water table etc.)

• Rainfall situation in the region of the site area

AREA REQUIREMENT FOR SLF

Height of Landfill = 5- 20 m

Infrastructure, support facilities & green belt = 15 -20 % of landfill

Landfill size classification

Small : < 5 hectares

Medium : 5- 20 hectares

Large : > 20 hectares

QA/QC Plan during construction of SLF

Permeability check of Mineralic Liner

Material Testing as per specifications

Compaction, Moisture content of Mineralic Liner

Vacuum Testing for HDPE Joints

Why does well designed SLF fail ?Why does well designed SLF fail ?

Improper operating practices

Allowed too much liquid to enter into the landfill

Cracks, punctures and physical failure of liners

Clogging of leachate collection systems

Consolidation may result in breaks in the liner or the

cover material

Disposal of solvents which affects the liner

Improper Joints