Ecological Revitalization and Reuse of Contaminated Sites Michele Mahoney, EPA 1.
The Truth about Ecological Revitalization - Case Studies and Tools to Improve your Cleanups
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Transcript of The Truth about Ecological Revitalization - Case Studies and Tools to Improve your Cleanups
The Truth about Ecological Revitalization - Case Studies and Tools to Improve your Cleanups
Sally Brown, University of Washington
Carbon Sequestration and Life Cycle Analysis
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Carbon Sequestration and Life Cycle AnalysisCarbon Sequestration and Life Cycle Analysis
Andrew Trlica and Sally BrownAndrew Trlica and Sally Brown
University of WashingtonUniversity of Washington
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Restoration SitesRestoration Sites
No soil or highly contaminated soil Disruption of process of carbon
accumulation/cycling
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How you restoreHow you restore
Use of organic amendments Will accelerate process But are changes in soil carbon persistent?
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Soil Carbon: RestorationSoil Carbon: Restoration
Andrew TrlicaFunded by Environmental Credit Corp, Jim Ellis, King County
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Coal Mine, WashingtonCoal Mine, WashingtonRestored in the 1980sRestored in the 1980s
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Centralia, WashingtonCentralia, WashingtonCoal Mine RestorationCoal Mine Restoration
52 Mg of C per hectare above conventional
0.25 Mg C per Mg biosolids
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Highland Valley Copper, British ColumbiaHighland Valley Copper, British Columbia6 – 8 years old 6 – 8 years old
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Highland Valley Copper, British ColumbiaHighland Valley Copper, British ColumbiaCoal Mine Restoration Coal Mine Restoration
40 Mg of C per hectare 0.3 Mg C per Mg amendment
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Pennsylvania Coal Mines – ControlPennsylvania Coal Mines – Control
NPK applied, 20 years ago
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Pennsylvania Coal Mines – BiosolidsPennsylvania Coal Mines – Biosolids
128 Mg ha applied, 27 years ago
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Pennsylvania – Historic SitePennsylvania – Historic Site
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That means…That means…
190 Mg of CO2 per hectare 0.9 Mg CO2 per Mg biosolids
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RMI Topsoils, New HampshireRMI Topsoils, New HampshireGravel pit restoration - 5 years oldGravel pit restoration - 5 years old
87 Mg of C per hectare 0.15 Mg C per Mg amendment
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Three separate sitesThree separate sitesData consistent across sitesData consistent across sites
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Biosolids- carbon credits for more than just Biosolids- carbon credits for more than just soil C accumulationsoil C accumulation
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CCX Draft protocol CHCCX Draft protocol CH44 avoidance to avoidance to
compost facilitiescompost facilitiesDefault Projected Yields of Waste Streams Diverted
from Landfilling
BECH4SWDSy
(C02e/wet ton waste diverted)
Waste type Year 1 Year 2 Year 3 Total
Food waste 0.28 0.23 0.19 0.7
Yard waste 0.11 0.1 0.09 0.3
Biosolids 0.05 0.04 0.03 0.12
Total = 1.12 Mg CO2
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Nutrient Value- 318 kg CONutrient Value- 318 kg CO22 per dry Mg per dry Mg
S. Plant kg per Mg
CO2 conversion
factor kg CO2 per Mg
N 70.1 3.96 278
P 22.5 1.76 40
K 0.22 1.2 0
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GHG balance for a biosolids programGHG balance for a biosolids program
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GHG balance for a hectare of land?GHG balance for a hectare of land?
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LCA for 1 ha in Pacific NorthwestLCA for 1 ha in Pacific Northwest
Compared Conventional restoration Restoration with organics (biosolids) Low density development
Used data on soil carbon from our sampling
Biosolids sent to dryland wheat as alternative
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HousingHousing1,000 people per km2
Structure size 2,521 ft2
3.86 homes per ha
Road 0.43 ha/ha
Open space 0.47 ha
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LCA ResultsLCA Results
Home and road construction and maintenance emissions dwarf biosolids tranpsort emissions
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TransportTransport
Under our baseline modeling assumptions the haul distance would need to be greater than 30 times the baseline assumption to eliminate the net sink effect in the whole conventional reclamation scenario
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SequestrationSequestrationSequestration
potential is greatest with biosolids restoration
Due to increased SOM Tree biomass
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Final ResultsFinal Results
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Additional ConsiderationsAdditional ConsiderationsRain and runoff
1 ha over 30 year period 646 ML of water 53% impervious cover 30% of rainfall = surface discharge 194 ML of water will require treatment
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Additional ConsiderationsAdditional Considerations Recreation
2009 tourism =$14.2 billion 37% camped, hiked or backpacked Assume 1% of tourism $$ result of access to outdoor activities 354 k ha forested land in King County Over 30 year period, each ha =$31,000
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ConclusionsConclusions
Using broader perspective further confirms benefits of restoration
Organics in restoration makes benefits one better
Sally BrownUniversity of WashingtonPhone: (206) 616-1299
Email: [email protected]