REMEDIATION OF A SUBSURFACE HYDROCARBON SYSTEM … · REMEDIATION OF A SUBSURFACE HYDROCARBON PLUME...
Transcript of REMEDIATION OF A SUBSURFACE HYDROCARBON SYSTEM … · REMEDIATION OF A SUBSURFACE HYDROCARBON PLUME...
Γολδερ Γολδερ ΓολδερΑσσοχιατεσΑσσοχιατεσΑσσοχιατεσ♣♣♣≤≤≤
A Mine is a Terrible Thing to WasteA Mine is a Terrible Thing to Waste
REMEDIATION OF AREMEDIATION OF ASUBSURFACE HYDROCARBONSUBSURFACE HYDROCARBONPLUME AT A MANUFACTURINGPLUME AT A MANUFACTURINGFACILITY IN ALBERTA USING AFACILITY IN ALBERTA USING A
VACUUM ENHANCED RECOVERYVACUUM ENHANCED RECOVERYSYSTEMSYSTEM
M. Jillian Mitton, M.Sc., P.Eng.-Golder Associates Ltd.Sarah Leonard, B.Sc., E.I.T.-Golder Associates Ltd.
OutlineOutline
Site Description and Background
Nature and Extent of HydrocarbonContamination
Remedial Objective
Remedial Action Plan
Remediation and Results
Summary
Site Description and BackgroundSite Description and Background
Source
Geological and Hydrogeological SettingGeological and Hydrogeological Setting
Nature and Extent of Hydrocarbon ImpactsNature and Extent of Hydrocarbon Impacts
Soil Plume (5,600 m2)
Groundwater Plume
(5,600 m2)
Product Plume
(2,300 m2)
Remedial ObjectiveRemedial Objective
Remedial Goal - AENV 2001 RiskManagement Guidelines for PetroleumStorage Tank Sites, commercial land-use and fine-grained soil.
Off-Site impacts - reduce all off-siteenvironmental liability by January 2003.
On-Site impacts - contain the impactson site and remediate the Site within a 3to 5 year time frame.
Remedial Action Plan
The selected remedial action planconsisted of:
1. Excavation and disposal of impacts onthe municipal road and adjacentcommercial property
2. Installation and operation of a vacuumenhanced recovery and treatment systemon the site.
Off Site RemediationOff Site Remediation
Off site remedial activities began inOctober 2002 and excavation work wascompleted in December 2002.
A total of approximately 2,600 tonnes ofimpacted soil was excavated andtransported off site.
Off Site RemediationOff Site Remediation
Excavationnext tocommercialbuildingwasconductedin a seriesof slots thatwere thenbackfilledwithfillcrete.
Private Sanitary Sewer
Off-Site RemediationOff-Site Remediation
Excavation in the road involved re-construction of sanitary and storm sewers anda water line.
Off-Site ResultsOff-Site Results
Remedial approach was effective inremoving off site liability by 2003.
Post excavation sampling wasconducted in May 2003 and allgroundwater concentrations were belowthe applicable guidelines.
On Site RemediationOn Site Remediation
A VER pilotstudy wasconducted inAugust 2002.
Results:
- 6 m radiusof influence;
- opt. vacuumof 10” Hg;
- airflow rate~36 scfm;and
- waterpumping rate~2.0 L/min.
On Site RemediationOn Site Remediation
Site preparation included installing 47 new wells;
Recovery wells were standard 2” diametermonitoring wells completed to depths rangingfrom 5.8 to 6.8 m.
Recovery well heads were installed on new wellsand 16 existing wells.
On Site RemediationOn Site Remediation
Winterized Recovery Lines
#1
#2 #3
#4
#5
#6
#7
On Site RemediationOn Site Remediation
On-Site RemediationOn-Site Remediation
1 2
3 4
On-Site ResultsOn-Site Results
Operation of the VER system began inJanuary 2003.
Results indicate that groundwater recoveryflow rates have ranged from 0.1 to 5.0 L/minand a total of approximately 11, 400 L ofgroundwater has been recovered over anoperational period of about six months.
The average air flow recovery rate for eachnetwork is 500 scfm.
On-Site ResultsOn-Site ResultsCorrelation Total BTEX (mg/m3) to PID Reading
0
200
400
600
800
1000
1200
1400
10 110 210 310 410Total BTEX (mg/m3)
PID
Rea
ding
s (p
pm)
On-SiteOn-Site Results Results
6
7
52/3
47 7 7
Total = 2,600L
0
500
1000
1500
2000
2500
3000
0 500 1000 1500 2000 2500 3000 3500 4000 4500
VER System Run Time (Hours)
Vo
lum
e o
f P
rod
uct
Re
cove
red
in V
ap
ou
r P
ha
se (
L)
#5
#7
#2/3
#6
#7
#1 #5Total Volume of Product = 2,600 L
#3/4
4100
On-Site ResultsOn-Site Results
Effluent water and ambient airconcentrations indicated that thesystem is effectively treating recoveredgroundwater and vapours.
VER system has removedapproximately 2,600 L of product over 6months.
The system is effectively containingimpacts on the Site.
Project SummaryProject Summary
Off-site remedial approach waseffective in removing off-site liability by2003
VER system is effectively containingimpacts on the site and recoveringhydrocarbons.
It is anticipated that the Site will beremediated within a 5 year time frame.
QUESTIONS ?