OUTLINEOUTLINE

Definitions Examples of Landfills in the Valley Construction on Landfills Materials Placement in Landfills Developments on Landfills – why develop landfills ?? Concerns Associated with Development on Landfills Landfill Materials Investigation Remediation of Construction and Demolition (C&D) Landfills Example Projects

DEFINITIONSDEFINITIONS

MSW Landfill C&D Materials Inert Debris Landfill

EXAMPLES OF LANDFILLS IN THE VALLEYEXAMPLES OF LANDFILLS IN THE VALLEY

C&D Landfills– Mostly Along the Salt River, Aqua Fria, Gila River &

Santa Cruz River– Created Generally by Mining of Aggregates for Concrete,

Asphalt, and Base Course Materials– Pits Left Behind are Backfilled with MSW or C&D– 24th St Vulcan Materials, 28th St ( Dean Thomas

Property), Salt River Pima Maricopa Dobson Plant– Tempe Market Place

EXAMPLES OF LANDFILLS IN THE VALLEYEXAMPLES OF LANDFILLS IN THE VALLEY

MSW Landfills– Queen Creek Landfill– 27th Ave Landfill– Tempe Municipal Landfill– Northwest Regional Landfill, and Others

Inert Debris Landfills– Salt River Materials Group Dobson Plant– 28th Street Landfill– 24th Street Landfill– Cotton Lane Landfill– Estrella Pit

MATERILAS PLACEMENT IN LANDFILLSMATERILAS PLACEMENT IN LANDFILLS

No Compaction During C&D Disposals No Processing is Completed Creates Nesting of Large Particles Blind Spots around Odd Shaped Particles Organics MSW Decomposes, Develops Settlement, LFG &

Leachate

MATERILAS PLACEMENT IN LANDFILLSMATERILAS PLACEMENT IN LANDFILLS

DEVELOPMENTS ON THE LANDFILLSDEVELOPMENTS ON THE LANDFILLS

Install Recreational Facilities Low Load Bearing Structures on Compacted MSW,

e.g. Distribution Center Heavier Structures on MSW should be on Deep

Foundations Industrial and Commercial Developments on C&D

CONCERNS ASSOCIATED WITH LANDFILL CONCERNS ASSOCIATED WITH LANDFILL MATERIALSMATERIALS

Large Settlement Uneven/Differential Settlements Unpredictable – No Model Available on Stability Compaction by Itself Biodegradation Piping, Internal Erosion and Raveling Gas (LFG) and Leachate Production, Accumulation

& Contamination of Air and Ground Water Organics in C&D Takes Too Long to Decompose

LANDFILL MATERIAL INVESTIGATIONLANDFILL MATERIAL INVESTIGATION

SOLUTIONS TO PROBLEMS FOR C&D SOLUTIONS TO PROBLEMS FOR C&D LANDFILLSLANDFILLS

Deep Dynamic Compaction (DDC) for Inert Debris Landfills

Compaction GroutVibrofloatation (Not Common)Remove and Reconstruct w/ Engineered

Fill/Debris

Deep Dynamic

Compaction (DDC)

Tempe Market Place

SOLUTIONS TO PROBLEMS FOR C&D SOLUTIONS TO PROBLEMS FOR C&D LANDFILLSLANDFILLS

Deep Dynamic Compaction (DDC):– Effective up to 30’-35’– 30-ton Load Drop from 80-90 feet Height, Multiple

Times– Imparts approx. 150 ton-ft/sq.ft. Equivalent to 150%

of Standard Proctor Compaction up to 25 Foot Depth– Evaluate Performance– Can’t Take Care of all Piping and Raveling

40002000

Deep Dynamic Compaction

24th Street and Salt River– Vibration Monitoring

Example Project, Load Test # 1ASTM D 1194-94

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0 50 100 150 200

Load , (Kips)

Ave

rag

e D

efo

rmat

ion

, (

inch

) .

Performance Evaluation with Plate Load Test

SOLUTIONS TO PROBLEMS FOR C&DSOLUTIONS TO PROBLEMS FOR C&D

Debris Fill Specifications– Anything as long as Inert Debris– 2 to 3 feet Lift Thickness– Compaction with 10 to 15 ton Equipment– 3 to 4 Passes with 20 to 30 hertz vibration– 30 to 60 Gallons/Cu.Yd. Water

Debris Fill Specifications

EXAMPLE PROJECTSEXAMPLE PROJECTS

Tempe Market Place28th Street and Salt River24th Street and Salt River14th Street and River View Drive

Tempe Market Place – Before Development

Tempe Market Place – During Stabilization

Tempe Market Place – After Development

24th Street & Salt River

CONCLUDING REMARKSCONCLUDING REMARKS

Environmental Benefits Aesthetic Improvement Monetary Value Added Land Use Positive Economic Impact Catalyst Stops Illegal Dumping