Successful On Site Bioremediation of Fuel-Contaminated Soil at CFS-Alert David Juck 1 , Danielle Beaumier 1 , Sylvie Sanschagrin 1 , Etienne Yergeau 1 , Andrew Tam 2 , Chris McRae 2 , Don Kovanen 2 , Drew Craig 2 , and Charles W. Greer 1 1 National Research Council Canada, Energy, Mining and Environment 2 National Defence, 8 Wing/CFB Trenton Environmental Management April 26, 2016 2016 RPIC Federal Contaminated Sites National Workshop
Presentation Outline • Site description of CFS-Alert • Challenges in the Arctic • Feasibility study • Ex situ biopile implementation • Opening the ‘Black Box’ • Conclusions 2
CFS-Alert 3
CFS-Alert • Built in 1950 as a weather station, Alert became a Canadian Military Communications Research Facility in 1956. At its peak of activity in the 1970’s, 200 military staff were stationed year around at CFS-Alert. • Currently about 50-80 staff, mostly civilian contractors • Our work there • Started in 2006 • Site characterization and delineation • In situ and ex situ bioremediation 4
CFS-Alert 5
Late August at CFS-Alert 6
Challenges in the Arctic • Temperature • Very short treatment window 10 0 -10 -20 -30 -40 February April June August December October • Average temperatures in June, July and August of -0.8°C, 3.3°C and 0.8°C, respectively. 7
Challenges in the Arctic cont. • Desert conditions • Total average annual precipitation is 153.8 mm (mostly in July, August and September) • Approximately the same as one month in Montreal • Permafrost • Impermeable barrier - can be a benefit or problem • Contain the contamination to upper 1m of soil • Horizontal movement of contamination during spring freshet • Stability of infrastructure is based on the stability of the permafrost 8
Challenges in the Arctic cont. • Logistics • Limited infrastructure • Limited heavy equipment access and operator time • Limited experience with remediation work • All materials have to come in by airplane • Can take 2 years to move material to site • Site history • Continual rotation of staff means little to no ‘corporate memory’ of previous activities or installations 9
CFS-Alert during heyday 10
Biodegradation Feasibility Study 11
Feasibility Study – ‘Worm Farm Soil’ • Diesel contaminated soil • Alternate treatments previously tried • Nutrient amendments • 20-20-20 (N-P-K) • MAP (mono- ammonium phosphate) • MAP most effective 12
Ex Situ Biopile 13
2006 Diesel Pipeline Spill 14
Biopile Construction • Biopile treatment area built in 2007 to treat a diesel spill • 40 x 100 m • Sand foundation, geotextile, impermeable membrane and sand base, berm approximately 2.0 m. 15
16
Contaminated Soils 2006 Diesel Pipeline Spill • Breach in diesel pipeline late September 2006 • Small amount of soil excavated at far end of spill • Majority of soil excavated during 2007 field season • Approximately 2,000 m 3 of soil in total Auxiliary Power Plant Spill 2007 • Spill during re-filling of fuel tank • Excavation within 24 hours of spill event • Approximately 500 m 3 of soil excavated Cat House Managed soils • Contaminated soils from 3 areas excavated and combined (2011) • Approximately 100 m 3 of soil • Contamination at least 12 years old 17
Biopile Treatment • Soil windrowed • T=0 samples collected • MAP treatment started in 2007 • ca. 250 kg MAP/year, turning once per year • < 50 mg MAP/kg soil over total treatment • Control pile – no MAP 18
PHC Mineralization Activity 2008 2010 50 70 A A 60 40 50 30 LO-1 40 LO-2 LN-1 LN-2 30 20 LC S-1 S-2 20 Mineralization (%) S-3 10 S-4 Mineralization (%) 10 HF sterile control 0 0 B B LO-1 60 LO-2 40 LN-1 LN-2 50 LC-1 SO-1 30 SN-1 40 SN-2 sterile control 30 20 20 10 10 0 0 0 10 20 30 40 50 60 0 5 10 15 20 25 30 35 40 19 Time (days) Time (days)
F2 Concentrations – 2006 and 2007 Spills • 2015 F2 average for all F2 biopile samples collected was 112 mg/kg (guideline F2 Concentrations (mg/kg) of 260 mg/kg) • No hotspots within biopile • No significant changes in control pile concentrations Biopile Control 20
‘Cat House’ Managed Biopile • Soils excavated from 3 F2 different areas at Alert 2000 • All spills over 15 years old F2 Concentrations (mg/kg) 1500 • F2 Starting average ca. 2,000 mg/kg 1000 • Average F2 concentration in August was 200 mg/kg 500 • One hotspot at guideline concentration (414 mg/kg) • ‘Aged’ soil responding very 0 rapidly to treatment 21
Opening the ‘Black Box’ 22
Who’s there? What are they doing? • We know that the PHCs are being degraded due to the treatment system • What are the population dynamics at play? • What biodegradation pathways are being stimulated? • Is the treatment targeting the organisms we want? • Molecular biological methods are now available to answer these questions • Targeting the DNA and RNA of the organisms present in the system 23
Metagenomic Analysis – Population Changes • Decrease in diversity upon contamination • High initial numbers of Gammaproteobacteria, decreased over time • increase over time in Actinobacteria • Main Gammaproteobacteria are Pseudomonas species • Low numbers of Pseudomonas in pristine soil • Increased dramatically following contamination • Dynamic system 24
Quantitative PCR • Following the gene copy number for alkane Gene Copy Number (copies/ng DNA) monooxygenase • Important first step in alkane biodegradation alkB (PspEu5&Pp) • Significant initial increase in alkB1 (Q15) Pseudomonas version • Delayed increase in Rhodococcus version • Similar trend when gene expression followed • Similar trend observed with ndoB (for aromatics biodegradation) Year 25
Conclusions 26
Conclusions • Bioremediation of PHCs is a viable option under Arctic conditions • Simple ‘passive’ biopile system effective on new and aged contamination • More is not necessarily better when it comes to treatment application • More frequent application of low concentration nutrients keeps the degraders happy • Inhibition of activity with high concentrations of nutrients • Cost effective solution • Estimated at $45/m 3 • Very active and dynamic indigenous microbial community 27
Thank you David Juck, Ph.D. Research Officer Tel: 514-496-5297 david.juck@cnrc-nrc.gc.ca www.nrc-cnrc.gc.ca 28 28
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