Geoffrey Delin and William Geoffrey Delin and William HerkelrathHerkelrathU.S. Geological SurveyU.S. Geological Survey
Scott Scott LounsburyLounsburyEnbridge Pipeline CompanyEnbridge Pipeline Company
USGS Toxics Substances Hydrology MeetingUSGS Toxics Substances Hydrology MeetingJanuary 26, 2009January 26, 2009
San Diego, CaliforniaSan Diego, California
Effects of Remediation at the Effects of Remediation at the Bemidji, Minnesota CrudeBemidji, Minnesota Crude--Oil Oil
Spill SiteSpill Site
OutlineOutline-- Pipeline rupture and initial remediationPipeline rupture and initial remediation
(1979)(1979)
-- Second phase of remediation (1998Second phase of remediation (1998--2004)2004)
-- USGS monitoring of the remediation USGS monitoring of the remediation
-- Introduction to other Bemidji presentationsIntroduction to other Bemidji presentations
Oil in spray zone
CrudeCrude--oil pipeline broke in August, 1979oil pipeline broke in August, 1979High pressure (3.5 High pressure (3.5 MPaMPa or ~500 psi), or ~500 psi), 86 cm (3486 cm (34--inch) inch) diameter pipeline diameter pipeline ruptured on ruptured on August, 20, 1979 August, 20, 1979 spilling 1,670 mspilling 1,670 m33
(10,500 barrels) of (10,500 barrels) of crude oil in an crude oil in an uninhabited area uninhabited area near Bemidji, near Bemidji, MinnesotaMinnesota
Minnesota
Bemidji Site
Site of pipelinerupture 1979
aerialphoto
Oil sprayzone
Crude oil sprayed over large areaCrude oil sprayed over large area
Oil pooled in low lying areas (≈2,000 m2) and sprayed over area of 6,500 m2
to the southwest of the pipeline that became known as the ‘spray zone’.
Views of Trench and PipelinesViews of Trench and PipelinesPipeline rupture site
Pipelines are ~3 m below land surface
Bemidji Crude Oil Spill SiteBemidji Crude Oil Spill SiteN
Research Site
Bemidji
Minnesota
North oil pool, 8/98
Observation well
Excavatedarea
Site ofpipeline
break, 8/79
Railroad tracks
Oil pipelines
Spray zone
Wetland0 80
50 100 150 200 250 Feet
20 40 60 100 Meters
0
0
South oil pool, 8/98Middle oil pool, 8/98
Generalized direction of ground-water flow
Oildrainage
area
Well 981
Remediation Remediation efforts led to efforts led to removal of ~ removal of ~ 75% of oil from 75% of oil from site (about 417 site (about 417 mm33 or 2,600 or 2,600 barrels of oil barrels of oil remained)remained)
1991 aerial photo
USGS & University Research1983 – Present
Many Research Groups Have Many Research Groups Have Been Involved at Bemidji SiteBeen Involved at Bemidji Site
Numerous USGS research teamsUniversity of British ColumbiaUniversity of ColoradoUniversity of KansasUniversity of MassachusettsUniversity of MinnesotaStanford UniversityUniversity of TexasUniversity of VirginiaUniversity of WaterlooBemidji State University Indiana UniversityEnbridge Pipeline CompanyMinnesota Pollution Control Agency
Significant Research HighlightsSignificant Research Highlights
Bemidji site one of first field sites where Bemidji site one of first field sites where natural attenuationnatural attenuation demonstrateddemonstratedResults and technologies transferredResults and technologies transferred to to numerous other sitesnumerous other sitesOil degradation is greater in areas of Oil degradation is greater in areas of increased rechargeincreased rechargeRedoxRedox processes change over small vertical processes change over small vertical intervalsintervalsSuccession from ironSuccession from iron--reducing to reducing to methanogenic microbial communities = slight methanogenic microbial communities = slight growth of the plume growth of the plume
Renewed Remediation Renewed Remediation –– 19981998
Well 981
Observation well
Excavatedarea
Site ofpipelinebreak
Infiltrationgallery Remediation
buildingOil
drainagearea
Oil pipelines
Spray zone
Wetland0 80
50 100 150 200 250 Feet
20 40 60 100 Meters
0
Generalized direction of ground-water flow
South oil poolFormer railroad tracks
Middle oil pool
North oil poolXX
XX
X
Remediationwell
Second phase of
remediation began in
December 1998
Objective: to remove oil to a sheen on water table in the wells
Predicted Remediation EffectsPredicted Remediation Effects
Total volume of oil per unit area prior to remediation, cm
Likely amount that can be recovered, cm
34
2
10
18
26
102
-60 -50 -40 -30 -20 -10 0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
X IN METERS
Y IN
MET
ER
S
Observation well
2
-60 -50 -40 -30 -20 -10 0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
X IN METERS
Y IN
MET
ER
S
Remediation well
147,000 L of oil, North Pool
37,000 L of oil, ~25% recoverable
Herkelrath, 1999
Installing Remediation Well Installing Remediation Well RWRW--1S, looking NW1S, looking NW
Pipeline rupture site
South pool
Hydrophobic soilin spray zone
DualDual--Pump Remediation SystemPump Remediation System
Skimmerpump
Remediationwell
To storagetank
Land surfaceLand surface
Unsaturated zoneFree product (crude oil)Saturated zone
LEGEND PUMPS ONPUMPS OFF
To storagetank
To separatortank and
infiltrationgallery
To separatortank and
infiltrationgallery
Remediationwell
Skimmerpump
Ground water pump
Ground water pump
Water TableWater Table
North Pool North Pool Remediation Remediation
WellsWells
RW-1N
RW-2N
Total pumping rate of water from all wells ~113 L/min (~30 gpm)
Remediation Remediation Building,Building,May 1999May 1999
Pipeline rupture site(looking NE)
Collaborative AgreementEstablished in 2008Established in 20082020--year duration year duration PartnersPartners: : 1. Scientists at the USGS and academic institutions, 1. Scientists at the USGS and academic institutions, 2. Enbridge pipeline company, 2. Enbridge pipeline company, 3. Beltrami County, and 3. Beltrami County, and 4. Minnesota Pollution Control Agency 4. Minnesota Pollution Control Agency Primary PurposePrimary Purpose: To promote research and : To promote research and educational opportunities educational opportunities Secondary PurposeSecondary Purpose: To test the effects of in: To test the effects of in--situ situ alternative remediation strategies at the site alternative remediation strategies at the site
Problems:Problems:LNAPL recovery, although common, is LNAPL recovery, although common, is expensive ($100,000expensive ($100,000’’s / year)s / year)BTEX analyses to evaluate contaminant BTEX analyses to evaluate contaminant migration and effects of remediation are also migration and effects of remediation are also expensiveexpensive
Simple, lessSimple, less--expensive methods are needed expensive methods are needed to evaluate remediation effectsto evaluate remediation effectsFew of these remediation studies are Few of these remediation studies are documented in the literaturedocumented in the literature
Opportunities:Opportunities:
LNAPL RemediationLNAPL Remediation
USGS Research ObjectiveUSGS Research Objective: : Evaluate effects of the oilEvaluate effects of the oil--recovery scheme using simple recovery scheme using simple methodsmethods
HypothesisHypothesis:: The renewed The renewed remediation would have an remediation would have an insignificant effect on oil insignificant effect on oil distribution, rates of volatilization, distribution, rates of volatilization, and rates of biodegradation. and rates of biodegradation.
Oil Thickness Measurements Oil Thickness Measurements
Using an oil-interface meter
Field Parameter Field Parameter Sampling Sampling
Well 981
Observation well
Excavatedarea
Site ofpipelinebreak
Infiltrationgallery Remediation
buildingOil
drainagearea
Oil pipelines
Spray zone
Wetland0 80
50 100 150 200 250 Feet
20 40 60 100 Meters
0
Generalized direction of ground-water flow
South oil pool Former railroad tracks
Middle oil pool
North oil poolXX
XX
X
Remediationwell
North pool North pool transecttransect
North Pool Transect of WellsNorth Pool Transect of WellsTo To ““Unnamed lakeUnnamed lake””
Vapor Transport MonitoringVapor Transport Monitoring
Well 981
Observation well
Excavatedarea
Site ofpipelinebreak
Infiltrationgallery Remediation
buildingOil
drainagearea
Oil pipelines
Spray zone
Wetland0 80
50 100 150 200 250 Feet
20 40 60 100 Meters
0
Generalized direction of ground-water flow
South oil pool Former railroad tracks
Middle oil pool
North oil poolXX
XX
X
Remediationwell
Periodic to annual sampling
Vapor samples analyzed in field using GC
Transect of vapor
wells
Vapor wellVapor well
Conceptual Vapor ModelConceptual Vapor Model
Residual oil
saturation UNSATURATED ZONE
CAPILLARY ZONE
SATURATED ZONE ANDDISSOLVED PLUME
VaporwellLand surface
Vaporprobe
Hydrocarbonflux
Methaneflux
Oxygenflux
CO flux
2
CRUDE OIL IN SMEAR ZONE AND FLOATING ON WATER TABLE
z6
z5
z4
z3
z2
z1
z0
FICK’S LAW
J = -D dGkkk
dzBiodegradation
Sand andgravelaquifer
Sorptio
n
Volatilization
1985 Methane Vapor, % of Atmospheric
Meters from center of oil
Elev
atio
n, m
eter
s
Floating oil
Upcoming Bemidji-Related Presentations
ORALS Technology transfer to Mandan, ND diesel spill siteLong term fate of intractable LNAPLsBemidji science drives model developmentTechnology transfer to Cass Lake, MN crude-oil spill site
POSTERSIron-reducing, in-situ microcosmTemperature as an indicator of microbial degradation Predicted effects of renewed remediationEffects of renewed remediationMethanogenic biodegradation of hydrocarbonsPush-probe reconnaissance (new tools)Reactive gas transport modeling Loss of volatile hydrocarbons in the oil: 1985 to 2008
Questions?