Floodplain Pilot Study Update
Floodplain Pilot Study Update Carbon Amendment of Floodplain Soil AOC 4, Former DuPont Waynesboro Site, Virginia
May 13, 2015
Agenda
– Background – Phase I Review – Phase II Overview – Phase III Design – Summary
Page 2
Background − Methylmercury (MeHg)- Bioaccumulative form of mercury − Use of carbon amendment − Integration for remedial design − Floodplain Pilot Study Objectives: • Test effectiveness of carbon amendments • Evaluate for potential unintended consequences
Page 3
−Study Phases: • Phase I: Laboratory Pilot (Completed 2014) • Phase II: Field Pilot (Spring/Summer 2015) • Phase III: Field Application (Pending 2016)
Page 4
Phase I Overview- Laboratory Pilot −Three Biochar treatments (Cowboy Charcoal): 0% (Control), 5% and 10% by dry weight −Two soils: RRM 11.8 soil and background soil based on total mercury (THg) concentrations −Soils sieved to < 2 mm and Biochar sieved to < 1.25 cm −Test receptors: Earthworms and plants −Conclusions: • Potential reduction in MeHg bioaccumulation • No adverse effects on earthworms or plants
Page 5
Phase II- Field Pilot −Validate the effectiveness and potential unintended consequences of using carbon amendments in situ
Page 6
Phase II- Study Location Augusta Forestry Station (RRM 11.8)
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Phase II- Study Design −Biochar rates 5% (unsaturated and saturated) and 10% (unsaturated)
Cowboy Charcoal
−Three replicates per treatment −In situ soil moisture and redox potential monitored for each treatment type −After aging for a few months, backgroundlevel (or laboratory-reared) worms will be added to cages and sampled after 4 and 8 weeks of in situ exposure Source: University of Waterloo 2011
Page 8
Phase II- Study Metrics −Adult and juvenile earthworm tissue: THg, MeHg, lipids −Survival and growth • Number, length and mass of adults
−Reproduction: • Number and length of juveniles or cocoons produced
−Soil: THg, MeHg, organic carbon
Page 9
Phase II- Mesocosm Cage Design
Sod and Topsoil
Mesocosm Section View
Slip Inside Perforated Top
Perforated Worm Mesocosm
Soil / Biochar Mixture
Mat’l: 316 S/S 12” Dia. x 16” High 1/8” Dia Holes ~40% Open Area
Woven Screen Liner Inside of Mesocosm
Mat’l: Polypropylene Opening: 0.030” x 0.025” 28 x 25 Mesh
Welded on Perforated Bottom Page 10
Phase II- Soil Moisture and Redox Monitoring − Redox potential and soil moisture monitored within dedicated cages for each treatment type and undisturbed resident soil − Probes connected to data-loggers for real-time data collection along the vertical profile of the cage
Page 11
Phase II- Soil Moisture and Redox Monitoring
Mesocosm Section View
Datalogger
Soil Moisture Probes Redox Probe (Maximum of 11 locations)
Page 12
Phase II- Schedule − Spring 2015 • •
Exposure cage construction Exposure cage deployment
− Summer 2015 Amendment Treatment Control Biochar- Wet (5%) Biochar- Dry (5%) Biochar- Dry (10%)
Not to scale Not to scale
Note: Phase II amendment exposure cage locations are preliminary. Final locations will be determined by field personnel based on study location site conditions.
Page 13
• • •
Worm deployment Week-4 monitoring Week-8 monitoring
Phase III (tentative)- Field Application − Study design: • AFC site • Biochar amendment • Till amendment material into soil to 7-12” • Age over winter • Collect resident earthworms and other invertebrates (e.g., predatory mite, collembolans, enchytraeid worms, spiders) Not to scale Control
Biochar (5%)
Biochar (10%)
Note: Phase III amendment plot locations are preliminary and are for discussion purposes only.
Page 14
Summary
−Phase II of the Floodplain Pilot Study will extend the Phase I study design into the field; mesocosm deployment is tentatively scheduled for the week of May 18th, 2015. −Phase III (pending) may evaluate potential reductions in mercury uptake in resident invertebrates in the natural field setting.
Page 15
THANK YOU QUESTIONS?
Phase II Floodplain Pilot Study Strategy
16
May 13, 2015
Agenda
– Background – Phase I Review – Phase II Overview – Phase III Design – Summary
Page 2
Background − Methylmercury (MeHg)- Bioaccumulative form of mercury − Use of carbon amendment − Integration for remedial design − Floodplain Pilot Study Objectives: • Test effectiveness of carbon amendments • Evaluate for potential unintended consequences
Page 3
−Study Phases: • Phase I: Laboratory Pilot (Completed 2014) • Phase II: Field Pilot (Spring/Summer 2015) • Phase III: Field Application (Pending 2016)
Page 4
Phase I Overview- Laboratory Pilot −Three Biochar treatments (Cowboy Charcoal): 0% (Control), 5% and 10% by dry weight −Two soils: RRM 11.8 soil and background soil based on total mercury (THg) concentrations −Soils sieved to < 2 mm and Biochar sieved to < 1.25 cm −Test receptors: Earthworms and plants −Conclusions: • Potential reduction in MeHg bioaccumulation • No adverse effects on earthworms or plants
Page 5
Phase II- Field Pilot −Validate the effectiveness and potential unintended consequences of using carbon amendments in situ
Page 6
Phase II- Study Location Augusta Forestry Station (RRM 11.8)
Page 7
Phase II- Study Design −Biochar rates 5% (unsaturated and saturated) and 10% (unsaturated)
Cowboy Charcoal
−Three replicates per treatment −In situ soil moisture and redox potential monitored for each treatment type −After aging for a few months, backgroundlevel (or laboratory-reared) worms will be added to cages and sampled after 4 and 8 weeks of in situ exposure Source: University of Waterloo 2011
Page 8
Phase II- Study Metrics −Adult and juvenile earthworm tissue: THg, MeHg, lipids −Survival and growth • Number, length and mass of adults
−Reproduction: • Number and length of juveniles or cocoons produced
−Soil: THg, MeHg, organic carbon
Page 9
Phase II- Mesocosm Cage Design
Sod and Topsoil
Mesocosm Section View
Slip Inside Perforated Top
Perforated Worm Mesocosm
Soil / Biochar Mixture
Mat’l: 316 S/S 12” Dia. x 16” High 1/8” Dia Holes ~40% Open Area
Woven Screen Liner Inside of Mesocosm
Mat’l: Polypropylene Opening: 0.030” x 0.025” 28 x 25 Mesh
Welded on Perforated Bottom Page 10
Phase II- Soil Moisture and Redox Monitoring − Redox potential and soil moisture monitored within dedicated cages for each treatment type and undisturbed resident soil − Probes connected to data-loggers for real-time data collection along the vertical profile of the cage
Page 11
Phase II- Soil Moisture and Redox Monitoring
Mesocosm Section View
Datalogger
Soil Moisture Probes Redox Probe (Maximum of 11 locations)
Page 12
Phase II- Schedule − Spring 2015 • •
Exposure cage construction Exposure cage deployment
− Summer 2015 Amendment Treatment Control Biochar- Wet (5%) Biochar- Dry (5%) Biochar- Dry (10%)
Not to scale Not to scale
Note: Phase II amendment exposure cage locations are preliminary. Final locations will be determined by field personnel based on study location site conditions.
Page 13
• • •
Worm deployment Week-4 monitoring Week-8 monitoring
Phase III (tentative)- Field Application − Study design: • AFC site • Biochar amendment • Till amendment material into soil to 7-12” • Age over winter • Collect resident earthworms and other invertebrates (e.g., predatory mite, collembolans, enchytraeid worms, spiders) Not to scale Control
Biochar (5%)
Biochar (10%)
Note: Phase III amendment plot locations are preliminary and are for discussion purposes only.
Page 14
Summary
−Phase II of the Floodplain Pilot Study will extend the Phase I study design into the field; mesocosm deployment is tentatively scheduled for the week of May 18th, 2015. −Phase III (pending) may evaluate potential reductions in mercury uptake in resident invertebrates in the natural field setting.
Page 15
THANK YOU QUESTIONS?
Phase II Floodplain Pilot Study Strategy
16
