Tank Storage AssociationTank Storage Association

Conference & Exhibition 22nd September 2011

Innovative solutions using bentonite materials to addressInnovative solutions using bentonite materials to address secondary and tertiary containment issues

Steve FlynnRawell Environmental Ltd

Bentonite for COMAH Containment Issues

Bentonite:

A natural clay which when hydrated forms a barrier to the passage of liquids

Supplied in rolls called a “GCL” laid like a carpet buried with ≥300mm fillSupplied in rolls called a GCL , laid like a carpet, buried with ≥300mm fill

Easily fixes to concrete structures

Self heals minor punctures

Minimal maintenance as membrane always below ground

2 types of GCL – “Dry” – needs to be carefully hydrated on site to functionyp y y y“Prehydrated” – already functions – just need to overlap

Bentonite Lining options “Dry” or “Prehydrated”

“Dry Bentonite”Dry Bentonite

Needs water to hydrate for bentonite to swell and form an impermeable seal

If hydrated with contaminated (site) water - bentonite will not function

Impurities in ground/water can prevent swell and cause failure

Therefore need to import inert material below and above membraneTherefore need to import inert material below and above membrane

Failure = Cation Exchange = causes change from Na+ to Ca++ = shrinks/cracks

Bentonite Lining options “Dry” or “Prehydrated”

“Prehydrated Bentonite”

Prehydrated bentonite is already a formed barrier ie 2.8 x 10-13 m/s

Prehydrated Rawmat® HDB does not need more water to form seal

Liquid polymer protected bentonite unaffected by hydrocarbons

Cation Exchange does not break down Rawmat® HDB – polymer protected

Fast simple installation with general contractors

Can be laid onto contaminated ground – no need for removal to landfill

Simple – strip earth, lay membrane, replace earth to form conforming barrier

Cost effective system – fraction of cost of concrete/clay

Examples of Issues to Consider

Bund walls – Vertical Concrete, Earth Berms, Composite “Hybrids”, , p y

Concrete Supports – Pipe Supports, Staircases, Ring Beams

Tank Bases – Concrete Ring Beams, Compacted Stone “Donuts”

Tank Floor Upgrades – Jacked Tanks, Replacement Floors

Bund Floor Drainage – “Rawdrain” & “PolyStorm”, “ACCO” Drain,

Pi P t ti T ll T il / F d i / i th h E th W llPipe Penetrations – Tell Tails / Feed pipes /pipes through Earth Walls

Tank Chimes – Corrosion Protection to Tank Floors

Sealing to Concrete Bund Wall

Bund wall

Rawmat HDB Type P terminated a minimum of 50mm below ground level and finished with a Rawmat termination bar fixed at 250mm centres with Rawmat soft washer fixings

300mm imported cover material Rawpaste Mastic applied in interface

between Rawmat and concrete bund wall

Compacted sub - base Rawseal TR35 angle filletRawmat HDB Type P laid white t til tnon - woven geotextile uppermost

Earth Bund Wall Sealing Options

Geogrid

Rawmat HDB

300mm

Rawcell filled with concrete at top of bund

300mm

Finish Level

Concrete cap forming anchor trench

Rawcell cellular confinement

200mm thick layer of stone in Rawcell

Rawmat HDB Type PP

of stone in Rawcell

Sealing to Concrete StructuresRawmat HDB Type P terminated a minimum

300mm Imported cover material

Rawpaste Mastic applied in interface between concrete sleeve, Rawmat HDB and Rawseal TR35. Existing concrete

of 50mm below ground level and finished with a Rawmat termination bar fixed at 250mm centres with Rawmat soft washer fixings

Compacted sub - base

Rawseal TR35 angle fillet Rawmat HDB Type P laid white non - woven geotextile uppermost

Tank Base – “Donut”

Rawdrain 444

SEE DRAWING No. 1708RBFOR OVERLAP DETAILS

Rawmat HDB Type PP

Tank Base – Concrete Ring Beam

TankTank

Rawmat HDB

Ring Beam

Rawmat HDB

Tank Floor Upgrades – Jacking & Letterbox

Bund Floor DrainageStone

50mm Stone Layer

Polystorm drain wrapped in terram and half filled with clean gravel

GeotextileRawpaste Mastic

250mm contaminated fill layer

Rawdrain 444400 - 450mm graded

75mm Clean Gravel

Drain Holes

Rawmat HDB Type P

400 450mm graded backfill placed over

Rawmat & Rawdrain

Rawmat Type PPRawdrain 444Compacted sub-base

Pipe Penetration through Earth Bund Wall

Main sheet of Rawmat HDB Type P laid white side facing upwards

Patch of Rawmat HDB Type P. White geotextile removed from and placed clay core side down. Patch must be a minimum of 200mm larger in all directions than diameter of pipe.

300

Rawpaste Mastic applied between sheets and around penetration

Upper white geotextile to be cut back in area to be overlapped by patch

500

500

300mm compacted suitable fill material

Pipe

Collar of Rawmat HDB Type P with the white non-woven geotextile removed and the clay core placed directly to

the pipe and held in place by wire or cable ties.

1

2.5Pipe penetration through earth bund that is no steeper than 1:2.5

Patch of Rawmat HDB Type P. White geotextile removed from and placed clay core side down. Patch must be a minimum of 200mm larger in all directions than diameter of pipe.

Rawpaste Mastic applied between sheets and around penetration

Collar of Rawmat HDB Type P with the white non-woven geotextile removed and the clay core placed directly to

the pipe and held in place by wire or cable ties.the pipe and held in place by wire or cable ties.

Close-Up Isometric View

Sealing Leak Detection Pipes

Rawdrain 444 extended above pipe to protect the Rawmat

Main sheet of Rawmat HDB Type PP with the lower geotextile removed in the area overlapping the first patch piece

Collar of Rawmat HDB Type PP with the geotextile removed from both sides

Rawseal TR35 angle fillet placed tightly around monitoring pipe.

Patch of Rawmat HDB Type PP with the upper geotextile removed

Monitoring Pipe

Rawpaste Mastic applied between all overlaps and applied to pipe

Tank Floor Corrosion Protection - Stopaq®

Tank Floor Corrosion Protection - Stopaq®

Tank

EZ Wrappingband

FN4200 sealant

Backer RodConcrete ring beam

S E l fSome Examples of Prehydrated Bentonite Membranes

used to provide Secondary Containment Solutionsused to provide Secondary Containment Solutions

Case Study: Linking Bund Wall to Floor

Irregular surface overlain with board and loose material smoothed out behind board which is then folded back to provide firm smooth surface for Rawmat HDB Type PP

Concrete cap forming anchor trench

150mm thick layer of concrete in geocell

Rawmat HDB Type PP

concrete in geocell

150mm nails through board into clay

Trench backfilled to bund floor level

As dug backfill

Board extends from base of trench and over slope

Trench cut square and Rawmat HDB Type PP buried in new clay

Imported clay

Case Study: Bund Wall Upgrade & Cut-Off Trench Dig

Case Study: Membrane Installation to Wall & Trench

Case Study: Cellular Confinement filled with concrete

Case Study: Installation to Corners & Completion of Bund

Case Study: Installation of membrane beneath Jacked tank

Case Study: Lapping, Covering of Membrane

Case Study: Extension of Bund - Singapore

Case Study: Installation in Heat, Humidity, Heavy Rainfall

Case Study: Sludge Lagoon Reconstruction - Australia

Case Study: Installation, lapping, Rawgrid

Case Study: Covering, Consolidation, Examination

Case Study: Membrane unaffected, Installation continues,

Case Study: Installation Continues..

Case Study: Sludge Lagoons Reinstated & Operational

US State of Florida

Dept of Environmental Protection

Unconditional Approvalpp

Rawmat® HDB - Prehydrated Bentonite

Bund Floor & Berm Lining

Under Tank Lining

Use in Saline Environments

No Need to Test Ground Conditions

No Need to Flood Bund

Tank Storage AssociationTank Storage Associationgg

Conference & Exhibition 22nd September 2011

Thank you for your attentionThank you for your attention

Questions?Questions?

To find out more, please visit our stand

Steve FlynnyRawell Environmental Ltd