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 ?