COMPARATIVE TEST ON SOIL SAMPLING - Welcome to …€¦ · · 2015-05-05VolatileorganicVolatile...
Transcript of COMPARATIVE TEST ON SOIL SAMPLING - Welcome to …€¦ · · 2015-05-05VolatileorganicVolatile...
CCOMPARATIVEOMPARATIVE TESTTEST ONON SOILSOILCCOMPARATIVEOMPARATIVE TESTTEST ONON SOILSOILSAMPLINGSAMPLING
AT A CLOSED FUEL STATION
Katarina Björklöfmicrobiologist & soil researcher
Finnish Environment Institute (SYKE)Reference Laboratory
Aim for this comparison was to 11 Aim for this comparison was to
● Compare sampling procedures of contaminated soil b i i d li
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between participated sampling teams ● Evaluate if the sampling design and procedure affected the
conclusion on the need for remediation
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● Demonstrate the use of quality procedures in sampling
● Expert planning group with different background
Setup of the comparison● Expert planning group with different background● In autumn 2008 during two weeks● Participants: nine sampling teams from different p p g
organizations (participation fee: 1000 euro)● Funded partly by Ministry of the Environment (40 %)
O f t SOILI● One reference team, SOILI
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The site11 The site21
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● Gasoline station
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(before 1990)● Area = 0.5 ha
C t i t● Contaminants detected by SOILI○ Hydrocarbons y
(C10-C21, C22-C40)
○ Volatile organic○ Volatile organic carbons (C5-C10, BTEX)
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Organization of field work● Not an authentic situation
○ Time limit 4,5 h.
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○ Detailed plan was required in advance based on history due to practical and financial reasons.
○ Amounts of samples to the lab limited (max 15)
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○ Amounts of samples to the lab limited (max 15).● Deviations due to other reasons than sampling planning
and procedures minimized:○ Same drilling equipment.○ All samples transported and stored by the organizersstored by the organizers.○ VOC samples fixed with
methanol on site.○ Samples analyzed at same
laboratory.● Sampling practices were also● Sampling practices were also
documented by the organizer. 4
T2
Slide 4
T2 Esitys tallennetaan muotoon PowerPoint-esitys (*.pptx). Tällöin kaikki esityksessä käytetyt ominaisuudet toimivat ongelmitta.
Voit poistaa tämän kommentin klikkaamalla hiiren oikeaa korvaa "Poista kommenti"Tekijä, 20/05/2011
11 Observations from field work● Experienced personnel most important factor for
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Observations from field work
valid sampling!○ Certification of sampling personnel
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● Big differences in homogenization procedures and storage of samplesstorage of samples
● Use of field instruments ○ Calibration? ○ Interpretation?
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11Quality of homogenization was
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determined by split samples
● One sample was divided into 2 subsamples and both were analyzed in the laboratory.
● Sampling teams with good homogenization practices had
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● Sampling teams with good homogenization practices had less than 10 % difference in concentrations between the subsamples
● The difference between hydrocarbon concentrations (C10-C21) in subsamples was up to 30 %.
● Careful mixing during field work increases the representability. S lit li d i iSplit sampling design i quality assurance tool
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11Heterogeneity of the site was
● Two sampling holes were drilled less than 0,5 m from each
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determined by repeated samplingp g ,
other.● Mean difference in hydrocarbon concentrations (C10-C21)
was 80 % (range 2% 177%)
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was 80 % (range 2% - 177%). ○ This is natural heterogeneity of the site which affect
uncertainties of field investigation!
● Large heterogeneity on site more samples are needed tomore samples are needed to reduce uncertainty of field investigation.
● Estimation of uncertainties should be estimated for every site specific investigation! g
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Maximum concentrations of PHCs found 11
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● Maximum conc. f d i d
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12000
14000
mg/
kg)
C10-C21C22-C40
● Only four groups detected hazardous waste concentrations ( )
8000
10000
entr
atio
n (m
concentrations ( )○ Affects costs!
● Max conc. did NOT 4000
6000
Max
. Con
ce
correspond to amount of samples investigated or use
f fi ld i t t
0
2000
N8 N3 N9 N2 SOILI N4 N6 N5 N1 N7M
of field instruments. Sampling team
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Determination of volatile organic 11
compounds (VOC) on the site21/1
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● * Samples kept in cold by sampling team.
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30
35
te V
OC
● Higher awareness of how to handle VOC compounds 20
25
/kg)
of s
epar
atun
ds
is needed (mixing, storing, fixing).
10
15
etra
tions
(mg/
com
pou
5
10
Max
. con
cne
0N6* N3* N7* N1 N5 N4 N2 N9 N8
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Estimation of soil to be remediated11
● All teams agreed,
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g ,that the site had to be restored.
● The estimated
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1500
1400
1600
ved
(t)
The estimated amount of soil to be remediated varied 10 times (range 1000
1200
be re
mov
( g140 -1 500 t soil).
● Most estimations were close to 415
468 480 480 500
780
600
800
f soi
l to
bexcecuted.
140
250300
415
200
400A
mou
nt o
f
0A
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Conclusions11
● Difficult to estimate performances of separate teams, because the matrix was very heterogeneous. The results of the SOILI team were not necessarily better than the others
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the SOILI team were not necessarily better than the others.
BUT
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● Comparison tests = good means to increase the awareness of quality issues in this field
● The results were presented at an open seminar with more than 60 participants interesting discussions!p p g
● Sufficient education and training of the sampling personnel is required. Guidelines are in preparation.D f lit t l ( t bilit● Demo: use of quality assurance tools (representability, uncertainties) increases the transparency of sampling procedures (e.g. split sampling taken into use!)
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11 Acknowledgement to group of 21
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Acknowledgement to group of experts:
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● Proficiency test providers○ I. Mäkinen & K. Korhonen,
SYKESYKE● Problem holders:
○ H. Westerholm, Neste Oil Oy○ S Nikunen SOILI –○ S. Nikunen, SOILI –
programme (Finnish Petroleum Federation)
● Legislators○ O. Pyy, SYKE
● Soil researchers○ K. Jørgensen & K. Björklöf,
SYKESYKE
Thank you for your attention!!12
11Need for restoration of contaminated soil is determined on site ● Level of contamination and the remediation need to be
d i ifi ll b i i f h h d d
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soil is determined on site
assessed site specifically by estimation of the hazard and damage of the contaminant on human health and on the environment.
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● Threshold value PHC = 300 mg/kg (C10-C21) and 600 mg/kg (C21-C40)
● Quality of sampling procedures difficult to measure and performance of the sampling team may affect the outcome of the assessment?
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