Environ Monit Assess DOI 10.1007/s10661-014-3649-1
Assessment of groundwater quality near the landfill site using the modified water quality index Izabela A. Talalaj
Received: 2 May 2013 / Accepted: 21 January 2014 # Springer International Publishing Switzerland 2014
Abstract The purpose of this paper is to assess the groundwater quality near a landfill site using the modified water quality index. A total of 128 groundwater samples were analyzed for pH, electrical conductivity (EC), total organic carbon (TOC), polycyclic aromatic hydrocarbon (PAH), Cd, Pb, Zn, Cu, Cr, and Hg. The analytical results have showed a decreasing trend in concentration for TOC, Cd, Pb, Hg, and Cu and an increasing one for pH, EC, and PAH. The modified water quality index, which was called landfill water pollution index (LWPI), was calculated to quantify the overall water quality near the landfill site. The analysis reveals that groundwater in piezometers close to the landfill is under a strong landfill impact. The LWPI in piezometers ranged from 0.52 to 98.25 with a mean value of 7.99. The LWPI in groundwater from the nearest house wells varied from 0.59 to 0.92. A LWPI value below 1 proves that analyzed water is not affected by the landfill. Results have shown that LWPI is an efficient method for assessing and communicating the information on the groundwater quality near the landfill.
I. A. Talalaj (*) Department of Environmental Engineering Systems, Bialystok University of Technology, Wiejska 45A Street, 15-351 Bialystok, Poland e-mail: [email protected]
Keywords Groundwater variability . Landfill impact . Pollution . Water quality index
Introduction Although landfills have been identified as one of the major threats to groundwater resources, they are still the most common method of waste utilization (Fatta et al. 1999; Mor et al. 2006). Waste placed in the landfill is subjected to a groundwater underflow and infiltration from precipitation (Mor et al. 2006). A combination of physical, chemical, and microbial processes in the waste transfers pollutant from the waste material to the percolating water creating a strong polluted leachate (Christensen and Kjeldsen 1989; Christensen et al. 1994, 2001; Kjeldsen et al. 2002; Durmusoglu and Yilmaz 2006). A landfill leachate contains a large number of compounds; some of which can be expected to be a threat to nature, especially to groundwater (Oman and Junestedt 2008). Because of a substantial risk to local resource users and to the natural environment, the assessment of the groundwater quality near to landfills should be an essential element of each landfill management. In Poland, some 10×106 Mg of waste is generated annually, from which approximately 90 % are deposited in landfills. In the year 2011, 578 landfills of municipal waste were operated occupying an overall area of 2,349.5 ha. Groundwater existing close to these landfills is subject to an infiltration of very contaminated water from improperly sealed or not sealed dumping sites or from surface runoffs from landfill areas. A grave
Environ Monit Assess
problem is damages to the geomembrane resulting in the penetration of runoff into the groundwater environment. The extent of the threat to groundwater can be different depending on the technical equipment of a landfill and the way it is operated. The scale of the impact depends on the kind of the ground environment as well as on the hydrogeological conditions around a given landfill (Appelo and Postma 1994; Pujari and Deshpande 2005; Rowe and Booker 2000). The impact of a landfill on groundwater has given rise to a number of studies in recent years, and many approaches have been made to assess the contamination of groundwater (Bocanegra et al. 2000; Abu-Rukach and Al.-Kofahi 2001; Calvo et al. 2005; Yenigul et al. 2005; Singh et al. 2008, 2009; Longe and Balogun 2010; Vasanthavigar et al. 2010; Gibrilla et al. 2011; Bhalla et al. 2012). In the present study, the impact of the Hryniewicze landfill in Poland on the groundwater quality has been assessed. The quality of groundwater has been estimated using the modified water quality index (WQI). The new modified index was called landfill water pollution index (LWPI). For the LWPI calculation, ten parameters, including heavy metals, were taken into account. The analysis of the LWPI in sampling points helped to understand the scale of the landfill impact and allowed to assess the variability of the groundwater quality in the vicinity of a landfill.
Materials and methods
two reservoirs. Then, the leachates are transported to municipal sewage treatment plant. All landfill sections are localized only in the eastern and northern parts of the landfill. The examined ground to a depth of at least 40 m is built of Quaternary Pleistocene strata. The Pleistocene is represented by a series of sandy formations underlaid with a complex of impermeable and firm boulder clays. Firm grounds are covered with peryglacial sands constituting the first water-bearing layer. Sands building the first aquifer have a variable strata thickness (0.7 to 12.0 m), a uniform granulation (ϕ=0.05÷0.20 mm), and a water permeability factor of the order of magnitude k=10−4 ÷10−5 m/s. For these parameters and low hydraulic gradient values, groundwater flow is 10 to 50 m/year. Groundwater level is at the datum approx. 139.0 to 142.0 m above sea level (i.e., at a depth of 0.95 to 5.4 m). The lowest groundwater level is to the east of the landfill and the highest to the west of the landfill (Fig. 1). The layout of hydroizohips within the landfill area points to a local watershed of Horodnianka River crossing the area under study. To the south and west of the landfill runs a watershed line between the rivers of Horodnianka and Niewodnica. The landfill site is underlain from the western side by groundwater that is flowing from beneath the landfill in the northeastern, southeastern, and eastern directions (Fig. 1). The nearest farm buildings are located 400, 500, and 650 m away from the landfill.
Area of study Methodology The Hryniewicze landfill is situated in the southeastern part of Podlasie Province of Poland. The operation started in 1981. The Hryniewicze landfill is one of the biggest landfill sites in Podlasie, where more than 400,000 m3 of municipal waste (apart from fluid waste, hazardous substances, radioactive, and toxic waste) is deposited annually. The Hryniewicze landfill consists of five sections (I, II, III, IV, V), from which the oldest one—section I—closed in 2001 is not equipped with a lining system; however, to protect the groundwater, it is sealed with a 50-cm clay layer. The rest of the sections are lined at the bottom with an impermeable 2-mm PEHD geomembrane. The leachates are collected by perforated pipes on the top of the liners and pumped to
In an effort to investigate the scale of the groundwater contamination, groundwater from four piezometers (P1, P2, P3, and P4) was analyzed. The P1, P2, and P3 piezometers were situated at the groundwater outflow from the landfill. The P4 piezometer was situated at the inflow of groundwater to the landfill and it was taken as a pollution background. The layout of hydroizohips (Fig. 1) indicates that the P4 piezometer is out of the range of the landfill influence. Field sampling was done four times a year, since 2004 till 2011. Additionally, in 2006, three groundwater samples were taken from the nearest house wells—S11, S9, and S10—situated 400, 500, and 650 m away, respectively, from the landfill.
Environ Monit Assess
A iver
ka R
ian rodn
Ho
140
1 41 142
B S11
P4 P3
II
0
143
14
1 42
I
C
IV V 14
P2
2 14 1 1 40
- sampling points 140 - ground water contour - road - streams/periodic stream B - line of hydrogeological profile A P1
141
P1
140
D S10
S9 1 40 W atershed
140
Fig. 1 The study area with groundwater sampling points and hydrogeological profile
Environ Monit Assess
Both piezometers and house wells were localized in the same aquifer. The groundwater samples were analyzed—according to the Polish Regulatory of Landfill Monitoring (Journal of Laws (Regulation of Minister of Environment concerning the landfills 2013))—for pH, EC, polycyclic aromatic hydrocarbon (PAH), total organic carbon (TOC), and six heavy metals Cr, Hg, Zn, Pb, Cd, and Cu. Determination was carried out according to the Polish standards. pH was measured the same day as the samples were collected, using potentiometric method (according to PN90/C-04540-01), EC—using conductivity method (PN-EN27888:1999). TOC was measured with infrared spectrometry method (PN-C-046333:1994), PAH—with HPLC method with fluorescence detection (PB-05-78/PAI 2:25.06.2007). The heavy metals—except for Hg—were analyzed by atomic emission spectrophotometry ICP-OES (PN-EN ISO 11885:2009), and Hg was determined by atomic absorption spectrophotometry (PB-IN 4:04.11.2010). Samples for the metal analyses were preserved by the addition of HNO3. Obtained results were the mean value of three determinations carried out simultaneously. Data analysis included mean, minimum, maximum, standard deviation, linear regression of chemical variation vs. time to determine the slope, and analysis of variance to determine effect of year on the groundwater quality. The modified WQI was used to estimate the landfill influence on water quality. The new formulated and modified index was called LWPI. For calculation of the LWPI, the following equation was used: n X
LWPI ¼
ðwi ⋅S i Þ
i¼1
n X
ð1Þ wi
Parameter
Weight (wi)
Relative weight (Wi)
pH
2
0.0667
EC
1
0.0333
PAH
5
0.1667
TOC
4
0.1333
Pb
3
0.1000
Cu
3
0.1000
Cr6+
3
0.1000
Hg
3
0.1000
Cd
3
0.1000
∑wi =30
∑Wi =1
inflow (background) groundwater sample. For the pH, the Si should be calculated by placing in the dominator of the lower pH value, as the ratio: C p =C b
if
cb < cp
C b =C p
if
cp < cb
or
ð3Þ
ð4Þ
The weight values wi were calculated for ten parameters involved in a landfill monitoring system (Regulation of Minister of Environment concerning the landfills 2013). The values of wi are given in Table 1. Setting the weight values for analyzed parameters, results of works, and analysis of Jones-Lee and Lee (1993), Flyhammar (1995), Christensen et al. (2001), Kjeldsen et al. (2002), Øygard et al. (2004), Mor et al. (2006), Oman and Junestedt (2008), Vasanthavigar et al. (2010), Cumar and Nagaraja (2011), and many others were taken into consideration. The maximum weight of 5 and 4 has been assigned to the parameters like PAH Table 2 Water quality classification based on LWPI value
i¼1
where LWPI is the quality index for groundwater impacted by a landfill, wi is the weight of the i-th pollutant variable, and n is the number of groundwater pollutants. The Si is calculated from the equation: S i ¼ C p =C b
Table 1 Weight for parameters used in LWPI
ð2Þ
where Cp is the concentration of the i-th parameter in each of a groundwater outflow (polluted) sample, and the Cb is the concentration of the i-th parameter in an
LWPI value
Interpretation
LWPI ≤1
Water under no landfill impact (for waters with certain impact of landfill, such a value may indicate pollution of inflow water (background) or improper localization of piezometers)
1
Assessment of groundwater quality near the landfill site using the modified water quality index Izabela A. Talalaj
Received: 2 May 2013 / Accepted: 21 January 2014 # Springer International Publishing Switzerland 2014
Abstract The purpose of this paper is to assess the groundwater quality near a landfill site using the modified water quality index. A total of 128 groundwater samples were analyzed for pH, electrical conductivity (EC), total organic carbon (TOC), polycyclic aromatic hydrocarbon (PAH), Cd, Pb, Zn, Cu, Cr, and Hg. The analytical results have showed a decreasing trend in concentration for TOC, Cd, Pb, Hg, and Cu and an increasing one for pH, EC, and PAH. The modified water quality index, which was called landfill water pollution index (LWPI), was calculated to quantify the overall water quality near the landfill site. The analysis reveals that groundwater in piezometers close to the landfill is under a strong landfill impact. The LWPI in piezometers ranged from 0.52 to 98.25 with a mean value of 7.99. The LWPI in groundwater from the nearest house wells varied from 0.59 to 0.92. A LWPI value below 1 proves that analyzed water is not affected by the landfill. Results have shown that LWPI is an efficient method for assessing and communicating the information on the groundwater quality near the landfill.
I. A. Talalaj (*) Department of Environmental Engineering Systems, Bialystok University of Technology, Wiejska 45A Street, 15-351 Bialystok, Poland e-mail: [email protected]
Keywords Groundwater variability . Landfill impact . Pollution . Water quality index
Introduction Although landfills have been identified as one of the major threats to groundwater resources, they are still the most common method of waste utilization (Fatta et al. 1999; Mor et al. 2006). Waste placed in the landfill is subjected to a groundwater underflow and infiltration from precipitation (Mor et al. 2006). A combination of physical, chemical, and microbial processes in the waste transfers pollutant from the waste material to the percolating water creating a strong polluted leachate (Christensen and Kjeldsen 1989; Christensen et al. 1994, 2001; Kjeldsen et al. 2002; Durmusoglu and Yilmaz 2006). A landfill leachate contains a large number of compounds; some of which can be expected to be a threat to nature, especially to groundwater (Oman and Junestedt 2008). Because of a substantial risk to local resource users and to the natural environment, the assessment of the groundwater quality near to landfills should be an essential element of each landfill management. In Poland, some 10×106 Mg of waste is generated annually, from which approximately 90 % are deposited in landfills. In the year 2011, 578 landfills of municipal waste were operated occupying an overall area of 2,349.5 ha. Groundwater existing close to these landfills is subject to an infiltration of very contaminated water from improperly sealed or not sealed dumping sites or from surface runoffs from landfill areas. A grave
Environ Monit Assess
problem is damages to the geomembrane resulting in the penetration of runoff into the groundwater environment. The extent of the threat to groundwater can be different depending on the technical equipment of a landfill and the way it is operated. The scale of the impact depends on the kind of the ground environment as well as on the hydrogeological conditions around a given landfill (Appelo and Postma 1994; Pujari and Deshpande 2005; Rowe and Booker 2000). The impact of a landfill on groundwater has given rise to a number of studies in recent years, and many approaches have been made to assess the contamination of groundwater (Bocanegra et al. 2000; Abu-Rukach and Al.-Kofahi 2001; Calvo et al. 2005; Yenigul et al. 2005; Singh et al. 2008, 2009; Longe and Balogun 2010; Vasanthavigar et al. 2010; Gibrilla et al. 2011; Bhalla et al. 2012). In the present study, the impact of the Hryniewicze landfill in Poland on the groundwater quality has been assessed. The quality of groundwater has been estimated using the modified water quality index (WQI). The new modified index was called landfill water pollution index (LWPI). For the LWPI calculation, ten parameters, including heavy metals, were taken into account. The analysis of the LWPI in sampling points helped to understand the scale of the landfill impact and allowed to assess the variability of the groundwater quality in the vicinity of a landfill.
Materials and methods
two reservoirs. Then, the leachates are transported to municipal sewage treatment plant. All landfill sections are localized only in the eastern and northern parts of the landfill. The examined ground to a depth of at least 40 m is built of Quaternary Pleistocene strata. The Pleistocene is represented by a series of sandy formations underlaid with a complex of impermeable and firm boulder clays. Firm grounds are covered with peryglacial sands constituting the first water-bearing layer. Sands building the first aquifer have a variable strata thickness (0.7 to 12.0 m), a uniform granulation (ϕ=0.05÷0.20 mm), and a water permeability factor of the order of magnitude k=10−4 ÷10−5 m/s. For these parameters and low hydraulic gradient values, groundwater flow is 10 to 50 m/year. Groundwater level is at the datum approx. 139.0 to 142.0 m above sea level (i.e., at a depth of 0.95 to 5.4 m). The lowest groundwater level is to the east of the landfill and the highest to the west of the landfill (Fig. 1). The layout of hydroizohips within the landfill area points to a local watershed of Horodnianka River crossing the area under study. To the south and west of the landfill runs a watershed line between the rivers of Horodnianka and Niewodnica. The landfill site is underlain from the western side by groundwater that is flowing from beneath the landfill in the northeastern, southeastern, and eastern directions (Fig. 1). The nearest farm buildings are located 400, 500, and 650 m away from the landfill.
Area of study Methodology The Hryniewicze landfill is situated in the southeastern part of Podlasie Province of Poland. The operation started in 1981. The Hryniewicze landfill is one of the biggest landfill sites in Podlasie, where more than 400,000 m3 of municipal waste (apart from fluid waste, hazardous substances, radioactive, and toxic waste) is deposited annually. The Hryniewicze landfill consists of five sections (I, II, III, IV, V), from which the oldest one—section I—closed in 2001 is not equipped with a lining system; however, to protect the groundwater, it is sealed with a 50-cm clay layer. The rest of the sections are lined at the bottom with an impermeable 2-mm PEHD geomembrane. The leachates are collected by perforated pipes on the top of the liners and pumped to
In an effort to investigate the scale of the groundwater contamination, groundwater from four piezometers (P1, P2, P3, and P4) was analyzed. The P1, P2, and P3 piezometers were situated at the groundwater outflow from the landfill. The P4 piezometer was situated at the inflow of groundwater to the landfill and it was taken as a pollution background. The layout of hydroizohips (Fig. 1) indicates that the P4 piezometer is out of the range of the landfill influence. Field sampling was done four times a year, since 2004 till 2011. Additionally, in 2006, three groundwater samples were taken from the nearest house wells—S11, S9, and S10—situated 400, 500, and 650 m away, respectively, from the landfill.
Environ Monit Assess
A iver
ka R
ian rodn
Ho
140
1 41 142
B S11
P4 P3
II
0
143
14
1 42
I
C
IV V 14
P2
2 14 1 1 40
- sampling points 140 - ground water contour - road - streams/periodic stream B - line of hydrogeological profile A P1
141
P1
140
D S10
S9 1 40 W atershed
140
Fig. 1 The study area with groundwater sampling points and hydrogeological profile
Environ Monit Assess
Both piezometers and house wells were localized in the same aquifer. The groundwater samples were analyzed—according to the Polish Regulatory of Landfill Monitoring (Journal of Laws (Regulation of Minister of Environment concerning the landfills 2013))—for pH, EC, polycyclic aromatic hydrocarbon (PAH), total organic carbon (TOC), and six heavy metals Cr, Hg, Zn, Pb, Cd, and Cu. Determination was carried out according to the Polish standards. pH was measured the same day as the samples were collected, using potentiometric method (according to PN90/C-04540-01), EC—using conductivity method (PN-EN27888:1999). TOC was measured with infrared spectrometry method (PN-C-046333:1994), PAH—with HPLC method with fluorescence detection (PB-05-78/PAI 2:25.06.2007). The heavy metals—except for Hg—were analyzed by atomic emission spectrophotometry ICP-OES (PN-EN ISO 11885:2009), and Hg was determined by atomic absorption spectrophotometry (PB-IN 4:04.11.2010). Samples for the metal analyses were preserved by the addition of HNO3. Obtained results were the mean value of three determinations carried out simultaneously. Data analysis included mean, minimum, maximum, standard deviation, linear regression of chemical variation vs. time to determine the slope, and analysis of variance to determine effect of year on the groundwater quality. The modified WQI was used to estimate the landfill influence on water quality. The new formulated and modified index was called LWPI. For calculation of the LWPI, the following equation was used: n X
LWPI ¼
ðwi ⋅S i Þ
i¼1
n X
ð1Þ wi
Parameter
Weight (wi)
Relative weight (Wi)
pH
2
0.0667
EC
1
0.0333
PAH
5
0.1667
TOC
4
0.1333
Pb
3
0.1000
Cu
3
0.1000
Cr6+
3
0.1000
Hg
3
0.1000
Cd
3
0.1000
∑wi =30
∑Wi =1
inflow (background) groundwater sample. For the pH, the Si should be calculated by placing in the dominator of the lower pH value, as the ratio: C p =C b
if
cb < cp
C b =C p
if
cp < cb
or
ð3Þ
ð4Þ
The weight values wi were calculated for ten parameters involved in a landfill monitoring system (Regulation of Minister of Environment concerning the landfills 2013). The values of wi are given in Table 1. Setting the weight values for analyzed parameters, results of works, and analysis of Jones-Lee and Lee (1993), Flyhammar (1995), Christensen et al. (2001), Kjeldsen et al. (2002), Øygard et al. (2004), Mor et al. (2006), Oman and Junestedt (2008), Vasanthavigar et al. (2010), Cumar and Nagaraja (2011), and many others were taken into consideration. The maximum weight of 5 and 4 has been assigned to the parameters like PAH Table 2 Water quality classification based on LWPI value
i¼1
where LWPI is the quality index for groundwater impacted by a landfill, wi is the weight of the i-th pollutant variable, and n is the number of groundwater pollutants. The Si is calculated from the equation: S i ¼ C p =C b
Table 1 Weight for parameters used in LWPI
ð2Þ
where Cp is the concentration of the i-th parameter in each of a groundwater outflow (polluted) sample, and the Cb is the concentration of the i-th parameter in an
LWPI value
Interpretation
LWPI ≤1
Water under no landfill impact (for waters with certain impact of landfill, such a value may indicate pollution of inflow water (background) or improper localization of piezometers)
1
