Evaluation of the Emergency Supply byDrinking Water Based on RiskAnalysis. Water Quality.Evaluation of the Emergency Supply byDrinking Water Based on RiskAnalysis. Water Quality.
František BOZEK, Adam PAWELCZYK, MagdalenaNÁPLAVOVÁ, Alexandr BOZEK
University of Defence, 65 Kounicova, 662 10 Brno, Czech RepublicUniversity of Defence, 65 Kounicova, 662 10 Brno, Czech Republic
Contact: phone.: + 420 973 443 170,Contact: phone.: + 420 973 443 170,
e-mail: frantisek.bozek@unob.cze-mail: frantisek.bozek@unob.cz
„Anybody who can solve the problems of environmental securitywill be worthy of two Nobel Prizes, one for peace and one forscience”„Anybody who can solve the problems of environmental securitywill be worthy of two Nobel Prizes, one for peace and one forscience”
IntroductionIntroduction
Under emergency or crisissituations the supplyof drinking water topopulation from publicwater supply systems isoften either limited ortotally broken.Under emergency or crisissituations the supplyof drinking water topopulation from publicwater supply systems isoften either limited ortotally broken.
The supply of water mayefficiently be solved,besides other alternativesources, by operating theground water sources,which form the unusedhydrogeological structures.The supply of water mayefficiently be solved,besides other alternativesources, by operating theground water sources,which form the unusedhydrogeological structures.
Assessed source HV-5 ofground water for emergencysupply of population bydrinking water in Pustimer▲ Assessed source HV-5 ofground water for emergencysupply of population bydrinking water in Pustimer
Theoretical PartTheoretical Part
During classification it is necessary to consider in relation toground water resources:During classification it is necessary to consider in relation toground water resources:
Risks result from natural and anthropogenic hazardsRisks result from natural and anthropogenic hazards
Health risks related to organoleptic, physical, chemicaland microbiological indicators of water;Health risks related to organoleptic, physical, chemicaland microbiological indicators of water;
Traffic accessibility;Traffic accessibility;
Availability;Availability;
Richness;Richness;
Economic criteria of operating.Economic criteria of operating.
Assessed source of ground water ►HV-102 for emergency supply ofpopulation by drinking water inDrnoviceAssessed source of ground water ►HV-102 for emergency supply ofpopulation by drinking water inDrnovice
Theoretical PartTheoretical Part
Water quality is one of the crucial criteria of classificationof ground water resources on the basis of risk analysis.Water quality is one of the crucial criteria of classificationof ground water resources on the basis of risk analysis.
If all the indicators meet hygienic standards it is possible touse the resource for emergency supply for unlimited periodof time. If water contains contaminants the concentrationsof which exceed the limit concentrations even after acommon water treatment then it is recommendedto apply the drinking water quality limits set for a month, aday, or a 10-days emergency supply.If all the indicators meet hygienic standards it is possible touse the resource for emergency supply for unlimited periodof time. If water contains contaminants the concentrationsof which exceed the limit concentrations even after acommon water treatment then it is recommendedto apply the drinking water quality limits set for a month, aday, or a 10-days emergency supply.
If there are contaminants the concentrations of which arehigher than the limits for drinking water and they do notexceed the limit indicators for a short-term emergencysupply health risk is recommended to be assessed.If there are contaminants the concentrations of which arehigher than the limits for drinking water and they do notexceed the limit indicators for a short-term emergencysupply health risk is recommended to be assessed.
Theoretical PartTheoretical Part
Out of the whole range of analyzed contaminants within theextended water analysis the attention has been paid to theHRA in relation to the content of As, Pb, Cd, Hg, Ni and Mn.Arsenic has been selected, because it is an element withproved human carcinogenity. Lead has been selected,because it belongs to the group of metals, which probablyhave carcinogenic effects. The metals with non-carcinogeniceffects included in the HRA are Cd, which is carcinogeniconly when inhaled, and also Hg, Ni and Mn. Mn has beenselected, because it represents the elements with adversecosmetic effects resulting in the colouring of teeth and skinand also aesthetic effects resulting in bad taste, smell andcolour of drinking water.Out of the whole range of analyzed contaminants within theextended water analysis the attention has been paid to theHRA in relation to the content of As, Pb, Cd, Hg, Ni and Mn.Arsenic has been selected, because it is an element withproved human carcinogenity. Lead has been selected,because it belongs to the group of metals, which probablyhave carcinogenic effects. The metals with non-carcinogeniceffects included in the HRA are Cd, which is carcinogeniconly when inhaled, and also Hg, Ni and Mn. Mn has beenselected, because it represents the elements with adversecosmetic effects resulting in the colouring of teeth and skinand also aesthetic effects resulting in bad taste, smell andcolour of drinking water.
Applied Methods and DevicesApplied Methods and Devices
Samples of drinking water have been taken in compliancewith the valid SOP.Samples of drinking water have been taken in compliancewith the valid SOP.
The concentration of metal elements in drinking water hasbeen determined by inductively coupled plasma atomicemission spectroscopy in compliance with the EU standards.The concentration of metal elements in drinking water hasbeen determined by inductively coupled plasma atomicemission spectroscopy in compliance with the EU standards.
The limits of determinability for individual elements withuncertainty 10% are presented in Table IThe limits of determinability for individual elements withuncertainty 10% are presented in Table I
Element
As
Pb
Cd
Hg
Ni
Mn
Limit of determinability
[mg dm-3]
0.005
0.003
0.0005
0.00025
0.001
0.050
Table I The Limits of Determinability of the Monitored ElementsTable I The Limits of Determinability of the Monitored Elements
Applied Methods and DevicesApplied Methods and Devices
Non-carcinogenic risk:Non-carcinogenic risk:
HQ = CDI RfD -1 (1) HQ = CDI RfD -1 (1)
HQ 1 acceptable risk (drinking water); HQ 1 acceptable risk (drinking water);
HQ (1; 4 tolerable risk (emergency water supply). HQ (1; 4 tolerable risk (emergency water supply).
CDI = cw b IR EF ED BW -1 AT -1 (2) CDI = cw b IR EF ED BW -1 AT -1 (2)
cn,a,(t) = HQ RfD BW AT b -1 IR -1 EF -1 ED -1 (3) cn,a,(t) = HQ RfD BW AT b -1 IR -1 EF -1 ED -1 (3)
Genotoxic riskGenotoxic risk
ELCR = 1 – e – (CSF CDI ) (4) ELCR = 1 – e – (CSF CDI ) (4)
ELCR 10-4 acceptable risk (drinking water); ELCR 10-4 acceptable risk (drinking water);
ELCR (10-4; 10-3 tolerable risk (emergency water supply). ELCR (10-4; 10-3 tolerable risk (emergency water supply).
cg,a,(t ) = ln [(1-ELCR)-1] BW AT CSF -1 b -1 IR -1 EF -1 ED -1 (5) cg,a,(t ) = ln [(1-ELCR)-1] BW AT CSF -1 b -1 IR -1 EF -1 ED -1 (5)
cn,t = cg,t = TDI BW IR -1 cn,t = cg,t = TDI BW IR -1
Applied Methods and DevicesApplied Methods and Devices
The risk has been calculated for one of the most vulnerableage group of infants up to the age of one year.The risk has been calculated for one of the most vulnerableage group of infants up to the age of one year.
Exposure Factor
IR
[dm3 day-1]
EF
[day month-1]
ED
[month]
BW
[kg]
AT
[day]
0.295
30
1
6.60
30
Table II The Values of Exposure FactorsTable II The Values of Exposure Factors
The value of IR has been determined as the median of the mean intakewater rate for particular age categories A1 1, A2 (1; 3, A3 (3; 6,A4 (6; 12 months.The value of IR has been determined as the median of the mean intakewater rate for particular age categories A1 1, A2 (1; 3, A3 (3; 6,A4 (6; 12 months.
BW has been calculated as the median of the 50 % smoothed percentileof the male and female body weights for the age categories birth, A1 1,A2 (1; 3, A3 (3; 6, A6 (6; 9, A7 (9; 12 months.BW has been calculated as the median of the 50 % smoothed percentileof the male and female body weights for the age categories birth, A1 1,A2 (1; 3, A3 (3; 6, A6 (6; 9, A7 (9; 12 months.
Applied Methods and DevicesApplied Methods and Devices
Table III The Values of Oral Reference Doses, Cancer Slope Factors andTolerable Daily IntakesTable III The Values of Oral Reference Doses, Cancer Slope Factors andTolerable Daily Intakes
Element
RfD[mg kg-1 day-1]
CSF[mg-1 kg day]
TDI[mg kg-1 day-1]
US EPA
WHO
CR
As
0.0003
1.5000
0.0003
-
-
Pb
-
-
0.0005
0.0036
0.0010
Cd
0.0005
-
-
0.0010
0.0035
Hg
0.0003
-
-
0.0020
0.0005
Ni
0.0200
-
0.0200
0.0120
0.0050
Mn
0.1400
-
0.0200
0.0600
0.0600
Table III shows the values of oral RfDs and CSFs for themonitored metals, necessary for the calculation of genotoxicand non‑carcinogenic risks. It also shows the TDI defined bythe US EPA, the WHO and the Czech standards.Table III shows the values of oral RfDs and CSFs for themonitored metals, necessary for the calculation of genotoxicand non‑carcinogenic risks. It also shows the TDI defined bythe US EPA, the WHO and the Czech standards.
Outcomes and DiscussionOutcomes and Discussion
There were 15 sources ofground water altogetherearmarked for the needs ofemergency supply of populationwith drinking water in theregion. Natural conditions,former exploitation of territoryin the vicinity of water resourceand its infiltration area wereconsidered during the selection.The drill holes were cleaned andwater was removed by suctionfor seven days prior thesampling for analysis at speedQ 0.3 dm3 s-1.There were 15 sources ofground water altogetherearmarked for the needs ofemergency supply of populationwith drinking water in theregion. Natural conditions,former exploitation of territoryin the vicinity of water resourceand its infiltration area wereconsidered during the selection.The drill holes were cleaned andwater was removed by suctionfor seven days prior thesampling for analysis at speedQ 0.3 dm3 s-1.
Assessed source HV7 ofground water for emergencysupply of population bydrinking water in Koberice▲ Assessed source HV7 ofground water for emergencysupply of population bydrinking water in Koberice
Outcomes and DiscussionOutcomes and Discussion
Table IV Limit Concentrations of Monitored Elements in Drinking Waterand in Water for a Short-Term Emergency SupplyTable IV Limit Concentrations of Monitored Elements in Drinking Waterand in Water for a Short-Term Emergency Supply
Element
Drinking Water
Emergency Supply
Limit concentrations[mg dm-3]
Limit concentrations[mg dm-3]
CR
EU
WHO
US EPA
CR
US EPA
One-month
One-day
Ten-day
As
0.010
0.010
0.010
0.010
0.030
-
-
Pb
0.010
0.010
0.010
0.015
0.010
-
-
Cd
0.005
0.005
0.003
0.005
0.030
0.040
0.040
Hg
0.001
0.001
0.006
0.002
0.002
0.002
0.002
Ni
0.020
0.020
0.070
0.100
0.250
1.000
1.000
Mn
0.050
0.050
-
0.050
1.000
1.000
1.000
Mna)
0.200
-
0.400
0.300
-
-
-
a) Limit concentration, if the concentration is affected by a bedrocka) Limit concentration, if the concentration is affected by a bedrock
Outcomes and DiscussionOutcomes and Discussion
Table V The Average Concentrations of Elements in Selected Drill HolesTable V The Average Concentrations of Elements in Selected Drill Holes
Drill HoleIdentification
Measured Concetration of Element[mg dm-3]
As
Pb
Cd
Hg
Ni
Mn
HV-1 Dedkovice
0.005
0.003
0.0005
0.00025
0.00321
0.0900
HV-1 Prusy
0.005
0.003
0.0005
0.00025
0.00634
0.0800
HV-10001 Racice
0.005
0.003
0.0005
0.00025
0.00379
0.1500
HV-102 Drnovice
0.005
0.003
0.0005
0.00025
0.001
0.0900
HV-4 Dedice
0.005
0.00762
0.0005
0.00025
0.02270
0.4200
HV-5 Pustimer
0.005
0.003
0.0005
0.00025
0.00744
0.1200
Vrt1 Drnovice
0.005
0.003
0.0005
0.00025
0.00495
0.050
M-2 Krenuvky
0.005
0.003
0.0005
0.00025
0.001
0.050
RV12 Racice
0.005
0.003
0.0005
0.00025
0.001
0.050
HV7 Koberice
0.005
0.003
0.0005
0.00025
0.00256
0.050
HV1 Lysovice
0.005
0.003
0.0005
0.00025
0.0285
0.050
HV1 Malinky
0.005
0.003
0.0005
0.00025
0.00102
0.0700
HV1 Orlovice
0.005
0.003
0.0005
0.00025
0.001
0.050
HV-5 Koberice
-
-
-
-
-
0.0850
HV-1 Teresov
-
-
-
-
-
0.050
Outcomes and DiscussionsOutcomes and Discussions
The concentrations of As, Pb, Cd, Hg and Ni have not beenmonitored in the drill holes HV-5 Koberice and HV-1 Teresov,because they have been excluded from the list of potentialresources suitable for emergency supply. The reason was thatwater from the HV‑5 Koberice drill hole contained over-limitconcentrations of SO42-, NO2- and the sum of minerals andthus did not meet even the limits of conductivity. Moreover,water did not meet the microbiological requirements due tothe occurrence of coliform bacteria, which indicate sewagecontamination and the KTJ 100 cm-3 of which significantlyexceeded even an incident limit. The HV-1 Teresov drill holehave been excluded from further assessment due to almostdouble excess of limit concentrations of NO3- and themicrobiological image showing the presence of live organisms.The concentrations of As, Pb, Cd, Hg and Ni have not beenmonitored in the drill holes HV-5 Koberice and HV-1 Teresov,because they have been excluded from the list of potentialresources suitable for emergency supply. The reason was thatwater from the HV‑5 Koberice drill hole contained over-limitconcentrations of SO42-, NO2- and the sum of minerals andthus did not meet even the limits of conductivity. Moreover,water did not meet the microbiological requirements due tothe occurrence of coliform bacteria, which indicate sewagecontamination and the KTJ 100 cm-3 of which significantlyexceeded even an incident limit. The HV-1 Teresov drill holehave been excluded from further assessment due to almostdouble excess of limit concentrations of NO3- and themicrobiological image showing the presence of live organisms.
Outcomes and DiscussionsAs, Cd, Hg, PbOutcomes and DiscussionsAs, Cd, Hg, Pb
The concentration of As, Cd and Hg in water of all13 monitored drill was below the level of determinabilityand met even the strictest limit set for drinking water.The concentration of As, Cd and Hg in water of all13 monitored drill was below the level of determinabilityand met even the strictest limit set for drinking water.
The analogous outcomeshave been acquired forthe concentration of Pb,which exceeded the levelof determinability only inthe HV-4 Dedice drillhole, but has still beenbelow the lowest limit fordrinking water.The analogous outcomeshave been acquired forthe concentration of Pb,which exceeded the levelof determinability only inthe HV-4 Dedice drillhole, but has still beenbelow the lowest limit fordrinking water.
Outcomes and DiscussionsNiOutcomes and DiscussionsNi
The limit value of determinability of Ni has been exceededin 9 monitored drill holes, out of which in 7 cases thestrictest national and EU standard for drinking water hasbeen met.The limit value of determinability of Ni has been exceededin 9 monitored drill holes, out of which in 7 cases thestrictest national and EU standard for drinking water hasbeen met.
The limit has beenslightly exceeded inthe water of 2 drillholes. However, it hasmet the hygienic limitsof WHO and US EPAfor drinking water.The limit has beenslightly exceeded inthe water of 2 drillholes. However, it hasmet the hygienic limitsof WHO and US EPAfor drinking water.
Outcomes and DiscussionsMnOutcomes and DiscussionsMn
The concentration of Mn has been measured in all15 resources of ground water.The concentration of Mn has been measured in all15 resources of ground water.
The concentration higherthan the limit for drinkingwater has been detected in8 cases and only in theHV-4 Dedice drill hole ithas been higher than thenational limit for groundwaters due to bedrock.The concentration has stillnot exceeded the limitsfor emergency supply.The concentration higherthan the limit for drinkingwater has been detected in8 cases and only in theHV-4 Dedice drill hole ithas been higher than thenational limit for groundwaters due to bedrock.The concentration has stillnot exceeded the limitsfor emergency supply.
Outcomes and DiscussionsOutcomes and Discussions
Type of Risk
Critical Concentrations cn,a for Acceptable
Non-Carcinogenic and cg,a for Genotoxic Risk
[mg dm-3]
As
Pb
Cd
Hg
Ni
Mn
Non-Carcinogenic
0.0067
-
0.0112
0.0067
0.4475
3.1322
Genotoxic Risk
0.0015
-
-
-
-
-
Table VI Critical Concentrations of the Monitored Metal Elements in Waterof Hydrogeological Structures for Drinking WaterTable VI Critical Concentrations of the Monitored Metal Elements in Waterof Hydrogeological Structures for Drinking Water
ss
Table VII Critical Concentrations of the Monitored Metal Elements inWater of Hydrogeological Structures for Emergency SupplyTable VII Critical Concentrations of the Monitored Metal Elements inWater of Hydrogeological Structures for Emergency Supply
Type of Risk
Critical Concentrations cn,t for Torelable
Non-Carcinogenic and cg,t for Genotoxic Risk
[mg dm-3]
As
Pb
Cd
Hg
Ni
Mn
Non-Carcinogenic
0.0268
0.0783
0.0447
0.0268
1.7898
12.529
Genotoxic Risk
0.0149
0.0783
-
-
-
-
Outcomes and DiscussionsOutcomes and Discussions
It is clear from the comparison of the criticalconcentrations of the assessed elements from Table VI andthe limit concentrations for drinking water from Table IVthat all limits for drinking water result in acceptable risk.The exceptions are arsenic and lead.It is clear from the comparison of the criticalconcentrations of the assessed elements from Table VI andthe limit concentrations for drinking water from Table IVthat all limits for drinking water result in acceptable risk.The exceptions are arsenic and lead.
Detail of the assessedHV7 Koberice drill hole▲ Detail of the assessedHV7 Koberice drill hole
As far as Pb is concerned thecritical concentration foracceptable risk could not becalculated with regard to thefact that neither RfD norCSF is defined for oralexposure. The TDI value hasbeen used for determiningthe tolerable contaminationof water by Pb.As far as Pb is concerned thecritical concentration foracceptable risk could not becalculated with regard to thefact that neither RfD norCSF is defined for oralexposure. The TDI value hasbeen used for determiningthe tolerable contaminationof water by Pb.
Outcomes and DiscussionsOutcomes and Discussions
For As the critical concentration cn,a correspondingto acceptable non-carcinogenic risk is cca 1.5 times lowerthan the hygienic limit for drinking water and the criticalconcentration cg,t characterizing the genotoxic risk is even7 times lower. The WHO states that the concentration of Asin natural waters is in the interval [As] 0.001; 12 mg dm3.It is technically quite difficult to reduce the concentrationof arsenic below 5 g dm3 through conventional methods,e.g. coagulation, even when the water treatment processesare thoroughly optimized. Besides that there are significantuncertainties in the risk determination and therefore thelimit 10 g dm3 for As is set as temporary.For As the critical concentration cn,a correspondingto acceptable non-carcinogenic risk is cca 1.5 times lowerthan the hygienic limit for drinking water and the criticalconcentration cg,t characterizing the genotoxic risk is even7 times lower. The WHO states that the concentration of Asin natural waters is in the interval [As] 0.001; 12 mg dm3.It is technically quite difficult to reduce the concentrationof arsenic below 5 g dm3 through conventional methods,e.g. coagulation, even when the water treatment processesare thoroughly optimized. Besides that there are significantuncertainties in the risk determination and therefore thelimit 10 g dm3 for As is set as temporary.
It is clear from Table VI that the critical concentration ofMn significantly exceeds the limit set for drinking waterearmarked also for emergency supply. This fact may beexplained by omitting the requirements for the quality ofdrinking water from cosmetic and aesthetic viewpoints whendetermining the critical concentrations of Mn. Moreover, itis known that higher concentrations of Mn negativelyinfluence organoleptic properties of water, such as taste,smell and color.It is clear from Table VI that the critical concentration ofMn significantly exceeds the limit set for drinking waterearmarked also for emergency supply. This fact may beexplained by omitting the requirements for the quality ofdrinking water from cosmetic and aesthetic viewpoints whendetermining the critical concentrations of Mn. Moreover, itis known that higher concentrations of Mn negativelyinfluence organoleptic properties of water, such as taste,smell and color.
Outcomes andDiscussionsOutcomes andDiscussions
Assessed drill hole HV1 in ►Malinky
ConclusionConclusion
Possible procedure of HRA resulting from the contaminationof ground water resources caused by selected metal elementshas been presented. The resources have been selected foremergency supply and the risk assessment has beenconducted for the most vulnerable age group of infants.Possible procedure of HRA resulting from the contaminationof ground water resources caused by selected metal elementshas been presented. The resources have been selected foremergency supply and the risk assessment has beenconducted for the most vulnerable age group of infants.
There have been 15 water resources assessed, out of which13 meet standards concerning the recommended 72 limitindicators and can be included into crisis plans. The outcomesof HRA of these 13 resources in relation to the contaminationby As, Pb, Cd, Hg, Ni and Mn mostly correspond to therecommended national Czech and EU limits.There have been 15 water resources assessed, out of which13 meet standards concerning the recommended 72 limitindicators and can be included into crisis plans. The outcomesof HRA of these 13 resources in relation to the contaminationby As, Pb, Cd, Hg, Ni and Mn mostly correspond to therecommended national Czech and EU limits.
The proposed procedure may be used as an example of waterquality assessment of ground water resources contaminatedalso by other contaminants.The proposed procedure may be used as an example of waterquality assessment of ground water resources contaminatedalso by other contaminants.
Thank you for yourpatient attentionThank you for yourpatient attention
Drinking WaterDrinking Water