The Truth about Ecological Revitalization - Case Studies
and Tools to Improve your Cleanups
Carbon Sequestration and Life Cycle
Analysis
Sally Brown, University of Washington
Carbon Sequestration and Life Cycle Analysis
Andrew Trlica and Sally Brown
University of Washington
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Restoration Sites
 No soil or highly contaminated soil
 Disruption of process of carbon
accumulation/cycling
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How you restore
 Use of organic amendments
 Will accelerate process
 But are changes in soil carbon persistent?
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Soil Carbon: Restoration
Andrew Trlica
Funded by Environmental Credit Corp, Jim Ellis, King County
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Coal Mine, Washington
Restored in the 1980s
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Centralia, Washington
Coal 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 Columbia
6 – 8 years old
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Highland Valley Copper, British Columbia
Coal Mine Restoration
 40 Mg of C per hectare
 0.3 Mg C per Mg amendment
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Pennsylvania Coal Mines – Control
NPK applied, 20 years ago
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Pennsylvania Coal Mines – Biosolids
128 Mg ha applied, 27 years ago
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Pennsylvania – Historic Site
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That means…
 190 Mg of CO2 per hectare
 0.9 Mg CO2 per Mg biosolids
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RMI Topsoils, New Hampshire
Gravel pit restoration - 5 years old
 87 Mg of C per hectare
 0.15 Mg C per Mg amendment
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Three separate sites
Data consistent across sites
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Biosolids- carbon credits for more than
just soil C accumulation
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CCX Draft protocol CH4 avoidance to
compost facilities
Default Projected Yields of Waste Streams Diverted
from Landfilling
BECH4SWDSy
(C02e/wet ton waste diverted)
Waste type
Food waste
Yard waste
Biosolids
Year 1
Year 2
Year 3
Total
0.28
0.23
0.19
0.7
0.11
0.1
0.09
0.3
0.05
0.04
0.03
0.12
Total = 1.12 Mg CO2
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Nutrient Value- 318 kg CO2 per dry Mg
S. Plant
kg per Mg
CO2
conversion
factor
N
70.1
3.96
278
P
22.5
1.76
40
K
0.22
1.2
0
kg CO2 per Mg
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GHG balance for a biosolids program
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GHG balance for a hectare of land?
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LCA 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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Housing
 1,000 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 Results
 Home and road
construction
and
maintenance
emissions
dwarf biosolids
tranpsort
emissions
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Transport
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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Sequestration
 Sequestration
potential is
greatest with
biosolids
restoration
 Due to increased
 SOM
 Tree biomass
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Final Results
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Additional Considerations
Rain and runoff
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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 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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Conclusions
Using broader perspective further
confirms benefits of restoration
Organics in restoration makes
benefits one better
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Sally Brown
University of Washington
Phone: (206) 616-1299
Email: slb@u.washington.edu