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CONSOIL 2005 CONSOIL 2005 Chlorinated compounds in groundwater : space time evolution case studies Philippe MONIER Philippe MONIER
CONSOIL 2005CONSOIL 2005
Chlorinated compounds in groundwater : space time evolution
case studies
Philippe MONIERPhilippe MONIER
Why monitoring ?Why monitoring ?
Groundwater monitoring answers Groundwater monitoring answers several points :several points :
Precise hydro geological network Precise hydro geological network Check on assumptions choice for DRA Check on assumptions choice for DRA Control hydro geological modelControl hydro geological model
So, monitoring has to answer questions ask So, monitoring has to answer questions ask during environmental studies. It’s not a goal during environmental studies. It’s not a goal in itself.in itself.
Chlorinated compounds in groundwater
During groundwater quality monitoring, During groundwater quality monitoring, chlorinated compounds show several chlorinated compounds show several space time evolution in regards of space time evolution in regards of hydro geologic framework, chemical hydro geologic framework, chemical and physical conditions etc.and physical conditions etc.
As a result, we can’t follow a simple As a result, we can’t follow a simple universal method for VOC groundwater universal method for VOC groundwater monitoring and each case needs to monitoring and each case needs to know what happen during know what happen during transportation of VOC in the plume.transportation of VOC in the plume.
What happened during What happened during flow ?flow ?
Pollutant transport in groundwater Pollutant transport in groundwater occur under effect of two phenomena occur under effect of two phenomena main types :main types :– Hydro geological main parameters :Hydro geological main parameters :
– advection advection – dispersiondispersion
– Chemical parametersChemical parameters– diffusiondiffusion– retardationretardation– degradationdegradation
Longitudinal dispersion
advection
Late
ral d
isp
ers
ion
Hydrogeological parametersHydrogeological parameters
Low concentration
Chemical parameters : Chemical parameters : diffusiondiffusion
High concentration
Pollutant flow
Chemical parameters : Chemical parameters : retardationretardation
grains
Free TCE
Dissolve TCE
Chemical parameters : Chemical parameters : degradationdegradation
Case 1 : Concentration vs. Case 1 : Concentration vs. time in a welltime in a well
WELL A
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1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
Date
Co
nce
ntr
atio
n µ
g/l
PCE
TCE
DCE
VC
Case 1 : Concentration vs. Case 1 : Concentration vs. time in plume cross sectiontime in plume cross section
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Concentration evolution during 10 years
Case 1 : Plume evolution Case 1 : Plume evolution during 12 yearsduring 12 years
TCE plume
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .0 0 828000 .00 828500 .0 0 829000 .00 829500 .0 0 830000 .00 830500 .0 0232000 .0 0
232500 .0 0
233000 .0 0
233500 .0 0
234000 .0 0
234500 .0 0
235000 .0 0
235500 .0 0
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
827500 .00 828000 .00 828500 .00 829000 .00 829500 .00 830000 .00 830500 .00232000 .00
232500 .00
233000 .00
233500 .00
234000 .00
234500 .00
235000 .00
235500 .00
Case 1 : Plume evolution Case 1 : Plume evolution during 12 yearsduring 12 years
VC plume
Case 1 : notingCase 1 : noting
VOC concentrations evolve in a same way for VOC concentrations evolve in a same way for PCE, TCE, DCE and VCPCE, TCE, DCE and VC
Plume don’t migrate down gradient after Plume don’t migrate down gradient after stopping reloadstopping reload
Evolutions observed every where in the plume Evolutions observed every where in the plume enable to the same conclusionenable to the same conclusion
There’s no specific evolution in specific point of There’s no specific evolution in specific point of the plumethe plume
Monitoring takes place near source to follow Monitoring takes place near source to follow concentration decreaseconcentration decrease
Case 2 Case 2 : Concentration vs. : Concentration vs. time in a welltime in a well
WELL NEAR SOURCE
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01-oct-00 19-avr-01 05-nov-01 24-mai-02 10-déc-02 28-juin-03 14-janv-04 01-août-04 17-févr-05
Dates
Co
nce
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atio
ns
PCE
TCE
DCE
VC
Case 2 Case 2 : Concentration vs. : Concentration vs. time in a welltime in a well
WELL DOWN GRADIENT
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80000
19-avr-01 05-nov-01 24-mai-02 10-déc-02 28-juin-03 14-janv-04 01-août-04 17-févr-05
Dates prélèvements
Co
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tio
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en
µg
/l
PCE
TCE
DCE
VC
Case 2 : notingCase 2 : noting
VOC concentrations evolve in opposite ways VOC concentrations evolve in opposite ways for PCE, TCE, DCE and VCfor PCE, TCE, DCE and VC
Evolutions observed in different point of the Evolutions observed in different point of the plume show different casesplume show different cases
According to location in the plume, we can According to location in the plume, we can find new products (unknown near source)find new products (unknown near source)
Monitoring takes place far down gradient of Monitoring takes place far down gradient of source to follow plume evolution and source to follow plume evolution and degradationdegradation
15/05/1992
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PCE
TCE
DCE
VC
17/03/1999
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0 100 200 300 400 500 600
PCE
TCE
DCE
VC
17/02/2000
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1400
1600
1800
2000
0 100 200 300 400 500 600
PCE
TCE
DCE
VC
29/08/2000
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2000
0 100 200 300 400 500 600
PCE
TCE
DCE
VC
25/07/2001
0
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1400
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2000
0 100 200 300 400 500 600
PCE
TCE
DCE
VC
12/11/2001
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800
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1400
1600
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0 100 200 300 400 500 600
PCE
TCE
DCE
VC
23/07/2002
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800
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0 100 200 300 400 500 600
PCE
TCE
DCE
VC
19/11/2002
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0 100 200 300 400 500 600
PCE
TCE
DCE
VC
12/02/2003
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0 100 200 300 400 500 600
PCE
TCE
DCE
VC
29/07/2003
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PCE
TCE
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VC
Case 3 Case 3 : longitudinal : longitudinal concentration evolution in a concentration evolution in a plume plume
Case 3 : notingCase 3 : noting
In this kind of plume, according to time, In this kind of plume, according to time, we can observed different evolution as we can observed different evolution as case 1 and case 2 case 1 and case 2
So : for VOC groundwater So : for VOC groundwater monitoring, what can I do ?monitoring, what can I do ?
In some case, evolution in each point In some case, evolution in each point of the plume are similar, so it’s easier of the plume are similar, so it’s easier to follow VOC concentration evolution to follow VOC concentration evolution near source to have high values.near source to have high values.
In an other case, if we are sure that In an other case, if we are sure that VOC degradation occur, the better VOC degradation occur, the better monitoring take place down gradient monitoring take place down gradient of the source, to follow MNA and of the source, to follow MNA and control congeneric concentration control congeneric concentration evolution. In this case, it’s better to go evolution. In this case, it’s better to go away from sourceaway from source
VOC groundwater VOC groundwater monitoring : right approachmonitoring : right approach
1.1. Geological and hydrogeological frameworks Geological and hydrogeological frameworks have to be perfectly knownhave to be perfectly known
2.2. VOC space-time evolution must be determine VOC space-time evolution must be determine to know whether MNA occur or notto know whether MNA occur or not
3.3. With these results, we can determine best With these results, we can determine best points for monitoring : on site or down gradientpoints for monitoring : on site or down gradient
4.4. And we can propose a right frequency And we can propose a right frequency
This approach guarantees an cost-effective monitoring
ATTENTIONATTENTION VOC concentrations in groundwater VOC concentrations in groundwater
answer to a sum of complex answer to a sum of complex hydrogeological and chemical hydrogeological and chemical characters which work together or in characters which work together or in opposite way.opposite way.
For these reasons, we can’t For these reasons, we can’t determine VOC concentration determine VOC concentration evolution only with two or three evolution only with two or three successive resultssuccessive results
We need several result to determine We need several result to determine and understand what happened in a and understand what happened in a plumeplume
TRI
0
50
100
150
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300
350
23/12/88 07/05/90 19/09/91 31/01/93 15/06/94 28/10/95 11/03/97 24/07/98 06/12/99 19/04/01 01/09/02
TRICas 1
Cas 2Cas 3
Attention : real case Attention : real case teaching !teaching !
TRI
0
20
40
60
80
100
120
140
160
19/09/91 08/11/91 28/12/91 16/02/92 06/04/92 26/05/92 15/07/92 03/09/92
TRI
Concentration increase during one yearTRI
0
5
10
15
20
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40
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50
20/02/95 11/04/95 31/05/95 20/07/95 08/09/95 28/10/95 17/12/95
TRI
Concentration decrease during one year
TRI
0
5
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15
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45
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09/07/99 28/08/99 17/10/99 06/12/99 25/01/00 15/03/00 04/05/00
TRI
Stability during one year
Thank you for your attention …..
