Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
Delaware’s venture into modern landfills.
Delaware’s venture into modern landfills.
N. C. Vasuki, P.E., DEECEO, Delaware Solid Waste Authority
www.dswa.com
N. C. Vasuki, P.E., DEECEO, Delaware Solid Waste Authority
www.dswa.com
IntroductionIntroduction■ Landfills provide the foundation for the State’s
solid waste management program■ In 1980 the first geomembrane (30 mil pvc) lined
landfill cell (9 acres) was constructed■ In 1982, a second cell (18 acres) was added.■ Leachate treatment became an issue.■ Dr. Fred Pohland’s research at Georgia Tech
appeared to provide a solution for our problem.■ Attempts were made to introduce leachate into
both cells.
■ Landfills provide the foundation for the State’s solid waste management program
■ In 1980 the first geomembrane (30 mil pvc) lined landfill cell (9 acres) was constructed
■ In 1982, a second cell (18 acres) was added.■ Leachate treatment became an issue.■ Dr. Fred Pohland’s research at Georgia Tech
appeared to provide a solution for our problem.■ Attempts were made to introduce leachate into
both cells.
Leachate recirculationLeachate recirculation■ Absence of prescriptive regulations allowed us
to experiment with various methods.■ Vertical recharge wells (perforated concrete
manhole sections) appeared to work.■ More wells were added and leachate export for
external treatment was reduced.■ Gas production also increased. Based on the
experience gained, we started improving our design.
■ Absence of prescriptive regulations allowed us to experiment with various methods.
■ Vertical recharge wells (perforated concrete manhole sections) appeared to work.
■ More wells were added and leachate export for external treatment was reduced.
■ Gas production also increased. Based on the experience gained, we started improving our design.
sw
sw
sw
sw
sw
sw
sw
sw
sp
spsp
sp
spsp
sp
sp
sp
sp
sp
sp
sp
sp
sp
sp
sp
sp
sp
P PP
P
P
PP
P
P
P
P
P
P
P
P
P
P
P P
PP
P
P
P
P
P
P
P
P
P
F F
F
F
F
F
F
C
PF C
C
C
I
w
GG
G
GG
L L
L
L
P/SP/S
P/S
sw
sw
sp
L
P/S
Property Boundary
Shallow Pleistocene
Pleistocene
Frederica Aquifer
Cheswold Aquifer
Gas Migration Monitoring Well
Water Supply Well
Irrigation Well
Surfacewater Sampling Point
Single Leachate Sampling Point
Duel Primary Leachate/Secondary
Detection Liquid Monitoring Point
P
F
C
G
w
I
LEGEND
Fig. 4: Sandtown Landfill - Locations of Groundwater, Leachate, and Surfacewater Monitoring Points
P
Area A-B
Area E
Area C-D
Jones Crossroads LandfillJones Crossroads Landfill■ DSWA’s southern landfill■ Four separate cells, Cells 1 through 4■ Leachate collected and pumped to tanks, hauled
by truck off-site. Limited volume recirculated.■ Landfill Gas collected and flared.■ Dead chickens disposal (emergency service)
created a hydrogen sulfide problem.
■ DSWA’s southern landfill■ Four separate cells, Cells 1 through 4■ Leachate collected and pumped to tanks, hauled
by truck off-site. Limited volume recirculated.■ Landfill Gas collected and flared.■ Dead chickens disposal (emergency service)
created a hydrogen sulfide problem.
S
S
SS
SS
S S S
S
S
S
S
SSS
S
S
S
S
SSS
S
S
S
S
S
M
M
M
M
M
M
M
M
M
M
M D
D
D
D
D
D
D
D
D
D
D
D
swswsw
sw
sw
sw
sw
spsp
sp
sp
P/SP/S
P/S
P/S P/S
L
w
L
L L
swsw
w
Cell 1Cell 2 Cell 3
Cell 4
LEGEND
Shallow Piezometers
Property Boundary
Shallow Columbia Wells
Deep Columbia Wells
Manokin Wells
Water Supply Wells
Surfacewater Sampling Point
Irrigation Wells
Single LeachateSampling Point
Primary Collection& Secondary DetectionMonitoring Point
sp
S
L
Iw
sw
MD
P/S
Fig.8 Jones Crossroads Landfill - Locations of Groundwater, Leachate, and Surfacewater Monitoring Points
Liner CostsLiner Costs
$3.77 $3.77 -- fPPfPP$3.99 $3.99 –– HDPEHDPECell 4Cell 4$6.45 $6.45 –– fPPfPP$4.31 $4.31 –– HDPEHDPEArea EArea E$5.70$5.70Cell 3Cell 3US$/smUS$/smCellCell
Liner Leakage RatesLiner Leakage Rates
None, to dateNone, to date12.112.1GeonetGeonetCell 4Cell 4102,237102,2377.47.413.213.2GeonetGeonetArea EArea E
62,42962,42915.915.99.79.7GeonetGeonetCell 3Cell 3813,056813,056115.6115.68.98.9SandSandArea DArea D
Total Total amount of amount of
liquid liquid collectedcollected
Liters/Liters/ha/dayha/day
Size of Size of cell (ha)cell (ha)
Type of leak Type of leak detection detection systemsystem
CellCell
Cap Costs & Leachate GenerationCap Costs & Leachate Generation
7,3367,336NANA80,25080,250Pigeon pt.Pigeon pt.Soil +PhytoSoil +Phyto
7067066,7756,775243,800243,800Jones crossJones crossCell 2Cell 2
6506502,7322,732324,900324,900Jones crossJones crossCell 1Cell 1
Leachate GenLeachate GenLiters/ha/dayLiters/ha/day
ACAC
Leachate GenLeachate GenLiters/ha/dayLiters/ha/day
BCBC
Cap Cost Cap Cost $/ha$/ha
LandfillLandfill
Cap costs & Leachate GenerationCap costs & Leachate Generation
8938934,0814,081175,700175,700SandtownSandtownCell DCell D
1,3181,3183,7103,710192,100192,100SandtownSandtownCell CCell C
3,7753,7753,4263,42667,80067,800SandtownSandtownCells A&BCells A&B
Leachate GenLeachate GenLiters/ha/dayALiters/ha/dayA
CC
Leachate GenLeachate GenLiters/ha/dayLiters/ha/day
BCBC
Cap costCap cost$/ha$/ha
LandfillLandfill
Current trends in leachate Current trends in leachate recirculation in Delawarerecirculation in Delaware
■■ Our new landfill cells use Horizontal pipes to Our new landfill cells use Horizontal pipes to introduce leachate into the solid waste mass.introduce leachate into the solid waste mass.
■■ The most promising method appears to be The most promising method appears to be the “Horizontal Injection Trenches” or HIT’s.the “Horizontal Injection Trenches” or HIT’s.
■■ The volume of leachate required to saturate The volume of leachate required to saturate the solid waste can be estimated using the the solid waste can be estimated using the build up of pressure as a guide.build up of pressure as a guide.
■■ The trench is allowed to rest and later the The trench is allowed to rest and later the same pipe can be used to extract LFG. same pipe can be used to extract LFG.
Data CollectionData Collection
■■ We are attempting to add to our already We are attempting to add to our already large data base with specific measurements large data base with specific measurements of LFG production from various cells. This of LFG production from various cells. This may help in improving our understanding of may help in improving our understanding of the behavior of landfill cells over a period of the behavior of landfill cells over a period of time.time.
■■ One must be patient in this respect and One must be patient in this respect and persistent in data collection. persistent in data collection.
What should USEPA do to help What should USEPA do to help improve landfills?improve landfills?
■■ Modify landfill cap requirements to Modify landfill cap requirements to allow more experimentation.allow more experimentation.
■■ For landfill cells with double liners, For landfill cells with double liners, phyto caps should be allowed.phyto caps should be allowed.
■■ Establish uniform criteria for collection Establish uniform criteria for collection of leachate and LFG data from all of leachate and LFG data from all landfills in the nation.landfills in the nation.
What else can USEPA do to help What else can USEPA do to help reduce emissions of LFG?reduce emissions of LFG?
■■ Expedite Title V permit issuance. It is Expedite Title V permit issuance. It is taking too long!taking too long!
■■ Actively support research to develop Actively support research to develop criteria for determining the end of the criteria for determining the end of the closure period of landfills.closure period of landfills.
■■ Actively support upgrading the training Actively support upgrading the training programs for landfill operators.programs for landfill operators.
Delaware’s venture into modern landfills.IntroductionLeachate recirculationJones Crossroads LandfillLiner CostsLiner Leakage RatesCap Costs & Leachate GenerationCap costs & Leachate GenerationCurrent trends in leachate recirculation in DelawareData CollectionWhat should USEPA do to help improve landfills?What else can USEPA do to help reduce emissions of LFG?