Journal of Global Resources

Volume 2

January 2016
Page 30-35
ISSN: 2395-3160 (Print), 2455-2445 (Online)

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ASSESSMENT OFGROUNDWATER AND LEACHATE QUALITY FROM BALAOANSANITARY LANDFILL IN LA UNION, NORTHERN PHILIPPINES
Leonora E. Ngilangil
Professor, Don Mariano Marcos Memorial State University
Bacnotan, La Union, Philippines
Email: lengilangil@gmail.com
Abstract: Landfills are point sources of pollution. In this study, it seeks to assess the groundwaterand leachate quality in Balaoan sanitary landfill using physico-chemical and biologicalcharacteristics and to compare the results to quality standards. Proper coordination withauthorities, ocular visits and surveys and final evaluation on the study site were made to ascertain
the presence of a leachate pond and deep/tube wells within or near the facility. Groundwater andleachate samples were collected through grab sampling during the months of February and Apriland sent for laboratory analyses .Except for the Total coliform and E.coli counts, the physicochemical parameters of the groundwater samples such as pH, turbidity, total dissolved solids, andnitrate were found to conform to the Philippine National Standards for Drinking Water(PNSDW).Leachate water samples in terms of Chemical oxygen demand were found to conformto the regulatory limit while toxic metals such as cadmium, chromium, copper, lead and mercury
showed very low concentration based on DAO 35, series of1990 class C waters.
Keywords: Groundwater, Landfill, Leachate, Physico-chemical, Waste Disposal
Introduction
Solid waste management remained to be a serious problem in the country. Despite the enactmentof Republic Act 9003 known as the Ecological Solid Waste Management Act, nothing has
improved. The volume of wastes being generated particularly in the urban centres tends toincrease with increased population growth. According to a 2012 World Bank report, South Asianand Pacific countries will have to cope with a 150% increase in household waste by 2025
(http://www.theguardian.com/world/2013/jan/29/manila-philippines-recycling-payatas
accessed
October, 15, 2015).Improper waste disposal is not only an eyesore but has serious environmental
consequences to the soil, air, ground and surface waters and even to human health. Groundwatercontamination may be the most serious problem caused by improper waste disposal because, as
usually the case in the Philippines, dependence on groundwater for drinking purposes is very
common. Sanitary landfills are the most widely utilized method for solid wastes disposal. In thePhilippines, there are about 960 sanitary landfills and of these, there are 936 controlled and open
dumps. Accordingly, sanitary landfills are waste disposal site designed, constructed, operated, andmaintained in a manner that exerts engineering control over significant potential environmental
impacts arising from the development and operation of the facility (RA 9003, 2001). However, it
would be noted that only few sanitary landfills operated by Local Government Units (LGUs)
complied with the minimum criteria set by the law such as the presence of liners, leachatecollection and treatment system, gas control recovery system, groundwater monitoring well system,a cover, and closure and post closure procedures. This is by far the biggest challenge faced by
Local government units because of financial limitations. There were lots of studies regarding solid
waste management, however, there were relatively few studies conducted to assess the level ofheavy metals contained in the landfills. In the study conducted by Galarpe and Parilla on analysisof heavy metals in Cebu Sanitary landfill in 2010, results revealed that the leachate stations
exceeded the standard for lead (0.1968 mg/L) and mercury (0.14838mg/L). Groundwater stationsin the landfill site also exceeded the standard for lead (0.0371 mg/L) and Cd (0.0042 mg/L). The

30

results could be alarming to public health and for the environment because heavy metals such as
cadmium, lead and mercury are carcinogenic substances.
In Region I, there are about 125 disposal facilities (EMB, 2012) with only 16 functional
sanitary landfills. Most of local government units are still on the process of converting theircontrolled dumpsite to sanitary landfill. In a controlled dumpsite, plastic liners are usually absent
which should provide cover or protection to the leaching of contaminants to the water table foundunderneath. The local government units (LGUs) are mandated by the Department of Environment
and Natural resources (DENR) to implement such criterion in the year 2005 as stipulated in RA
9003, however, due to financial and technical constraints, such policies were not properly
implemented. The potential effects or impacts of waste disposal facilities may then become greater
if there would be no constant monitoring and assessment on their status. The first establishedsanitary landfill is found in the City of San Fernando, La Union. Serving as a model to the adjacenttowns, the municipality of Balaoan, about 33.5kilometers north of the city, also established its
sanitary landfill in 2008 in compliance to RA 9003.However, there has been no data yet on theimpact brought about by the disposal facility since it started operation. With this, there is a need toassess the status of the waste disposal facilities as to their impacts on the groundwater and tocharacterize the leachate quality in order to establish baseline information which in turn could be
used in the formulation of policies for local waste management and health prevention in local
government units.
Objectives
General Objective: To determine the groundwater and leachate quality from the waste disposal
facility.
Specific Objectives:
1. Determine the groundwater quality of tube/deep wells adjacent or near waste disposal
facility in terms of:a. Physical parameters
b. Chemical parametersc. Biological parameters
2. Characterize the leachates from the waste disposal facility in terms of toxic metals
concentration.
3. Find out the deviation of the physico-chemical parameters of the groundwater and leachatewater from the environmental quality standards.
Materials and Methods
Study Area
Balaoan is a first class municipality (Figure 1) which has a current population of 37, 910.With 36
barangays, its total land area is about 6,870 hectares (17,000 acres) consists mostly of agriculturallands. It occupies 4.3% of the total area of the province. With geographical coordinates of 160 19’
30” North, 1200 22’ 7” east, the municipality generates about 25.5 cu. M. of wastes/day. The town
has been adjudged one of the outstanding municipalities because of its coastal resource
management.
The study area (Figure 2) is the Balaoan Sanitary Landfill with a total land area of 1 ha.
Originally, a marginal forest in Calumbuyan, the landfill is converted in 2008 in compliance toenvironmental laws particularly the RA 9003 known as the Ecological Solid waste Management Act
of 2000. The bulk of the municipal wastes are mostly organics and inorganics composed of
biodegradable and non-biodegradable wastes. These wastes when decayed results to leachatethat would be contained in the leachate pond. The leachate pond is located between latitude 160
48’, 42.9 ‘N and longitude 120 0 23 ‘ 21.2 ‘’ with an elevation of 68 meters.

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Figure 1: Municipality of Balaoan

Figure 2: Balaoan Sanitary Landfill[[

Water Analyses
Field survey was made to ascertain the presence of deep or shallow tube wells near the disposal
facility. A shallow tube well and a communal deep well constructed from a flowing water (spring)were selected in a 500 m radius near the waste disposal facility where water samples were taken
for analyses. In the study, the 1st groundwater sample was taken from a deep well from a residence
nearby located between latitude 160 48’ 45.2.” N and longitude 1200 23’ 21.2 “while the second
ground water sample was obtained from a constructed shallow well located between latitude 160
48’ 44.3 “”N and longitude 1200 23’ 35.9 “. Grab sampling method were used and ground water
samples were taken manually, placed in plastic and sterilized containers, properly sealed andlabelled, and preserved with ice at lower temperature inside coolers for storage and transport readyfor laboratory analyses. The sampling and analyses was conducted by CRL Environmental
Corporation, an ISO accredited laboratory situated in Clark, Pampanga, Philippines during themonths of February and April of the year.
The groundwater samples were analyzed in terms of physical, chemical and biologicalparameters such as pH, temperature, turbidity, conductivity, Total dissolved solids (TDS), nitrate,
Total nitrogen, Total phosphorous, Total coliforms, and Fecal coliforms. The pH was measured
using a calibrated pH meter and a glass electrode while the conductivity was measured by the useof self-contained conductivity meter. Total dissolved solids were measured following thegravimetric method. Turbidity was measured using the turbidity meter while nitrate was analyzed
using the Cadmium Reduction method. Total Nitrogen and Total phosphorous were measured
using the Total Kjeldahl Nitrogen and the colorimetric method respectively.
Leachate Concentration
Leachate is the liquid that drains or leaches from a landfill. It accumulates at the bottom of thelandfill and percolates through the soil. The composition varies depending on the age of the landfill
and the type of wastes that it contains. Further, the quality of leachate is determined primarily by
the composition and solubility of the waste constituents (Khateeb, 2010). For instance, if thewastes changes in composition due to weathering or biodegradation, then leachate quality willchange with time. The Balaoan Sanitary Landfill utilized the trench method of treatment whereby
the liquid drains into a pond. In here, the delivered municipal wastes are dumped into the cell,compacted and covered with soil layer to minimize risk, reduce odors and reduce windblown
garbage. The leachate pond was situated between 16048’42.9.” N and 1200 23’ 21.2” During thesampling, it was noted that the pond was covered with water hyacinth- a water plant potential in
waste water treatment. In this study, the leachate samples were also collected through grab
sampling and placed in a plastic container properly sealed and labelled. The parameters such as

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pH, chemical oxygen demand, total nitrogen, cadmium, chromium, copper, lead and mercury wereconsidered for laboratory analyses.
Chemical oxygen demand (COD) is a measure of the capacity of water to consume
oxygen during the decomposition of organic matter and the oxidation of inorganic chemicals suchas ammonia and nitrate (http:// science.jrank.org).The COD measurement was done using theOpen reflux method. The total nitrogen was measured taking the summation of Total Kjeldahl
Nitrogen (TKN), nitrates and nitrites concentrations. The nitrates and nitrites were measured using
the Cadmium Reduction method. Total Phosphorous was measured using the colorimetric method.
The atomic absorption spectroscopy was used in the measurement of cadmium, chromium, copperand lead. Mercury measurement was done using the cold vapour technique.
Results and Discussion
Municipal solid wastes (MSW) usually generated from local government units which are notproperly segregated would produce toxic chemicals that would pose a substantial risk to local
resource user and to the natural environment. Non-hazardous municipal wastes, for example,
produce leachate with near neutral pH in the early stages of decomposition, but as decomposition
processes develop, waste becomes anaerobic and leachate may turn to a slightly to strongly acidic
pH. It is also at this stage that ammonium and metal concentrations also rise. After several months
or years, methanogenic conditions are established where the leachate becomes neutral or alkaline
but with significant quantities of ammonia. Groundwater pollution by leachate from landfills isdetermined by factors such as the concentration of contaminant, permeability of the geologic
strata, the type of geologic strata, the toxicity of the contaminants, and the direction of the water
flow. Table 1 shows the test results of the groundwater samples taken from the two sites and thecorresponding Philippine National Standards for Drinking Water (PNSDW) 2007 limits.
Table1: Summary of Results on Groundwater Samples in Balaoan Landfill
Parameters, unitsst

1 sampling2ndsampling

PNSDW 2007
Limits

GW1
GW2
GW1
GW2
pH
6.2
6.4
5.9
6.3
6.5-8.50Temperature, C
30.2
30.2
27.8
28.2
--Turbidity, NTU
0.65
5.0
1.2
5.0
5.0
Conductivity, uS/cm
444
474
287
288
---TDS, mg/L
320
341
214
161
500
Nitrate, mg/L
3.0
1.80
4.60
3.0
50
Total Nitrogen, mg/L
<1.0
<1.0
1.0
<1.0
--Total Phosphorous, mg/L
<0.004<.0.1<0.004
0.3---Total coliforms, MPN/100mL
>23
>23
>23
>23
<1.1
Fecalcoli forms, MPN/100m
3.6
3.6
>23
12
<1.1
Source: CRL Environmental Lab. Inc. 2015. (GW1- Groundwater station 1 GW2 – Groundwater station 2)

Based on the results analysed for the groundwater samples, total and fecal coliforms
results are still the non-conforming parameters set by PNSDW. Other parameters tested such as
pH, turbidity, conductivity, total dissolved solids, nitrate satisfies the PNSDW limits, though someparameters do not have corresponding limits. The pH of the water samples in both samplingstations did not conform to the PNSDW limits. The values showed slightly acidic which suggeststhat it could make a negative impact to aquatic life and human health. Total dissolved solids(TDS)comprise of inorganic salts such as magnesium, potassium, sodium, bicarbonates, calcium,chlorides and sulphates with some small amounts of organic matter that are dissolved in water. In
the study, values for TDS are still below the standards, however, the values which ranged from 161
to 341 still indicates pollution. It would be noted, that the samples were taken during dry season(February and April) when precipitation is low, thus, the values for TDS are expected to increase
when precipitation also increases. The conductivity of the water showed appreciable values which33

ranged from 287 to 474. This means that the water is affected by the presence of inorganic
dissolved solids such as chloride, nitrate, sulphate, and phosphate anions (ions that carry anegative charge) or sodium, magnesium, calcium, iron, and aluminium cations (ions that carry apositive charge). Conductivity is closely associated to salinity. Conductivity increases astemperature increases. Nitrates may get into the drinking water through run-off from fertilizers,
leaks from septic tanks, sewage and erosion of natural deposits. As gleaned from the results, thewater samples in both stations showed very minimal amounts as based from the PNSDW limit.
However, EPA maximum contaminant level (MCL) is 10mg/L. Total coliforms result is the estimateof the amount or density of rod-shaped coliform bacteria and an indicator of drinking water quality.
Coliform bacteria are common inhabitants in soils, plants and animals that may come in contact
with water. They are not harmful but their presence may also indicate the presence of pathogens
from fecal origins and other disease causing microorganisms. The results suggests that the watertaken from these deep wells should not be used for drinking purposes as this may cause healthproblems associated with these pathogens which include diarrhoea, cramps, nausea, and vomiting(http://water.epa.gov/lawsregs/rulesregs/sdwa/tcr/basicinformation). As observed, the second
station is a communal source of drinking water since this is spring water.
The location of the landfill has a significant impact in the process of leaching. The locationof the groundwater sampling sites to that of the leachate well (figure 2) were positioned below theleachate well since groundwater 1 has an elevation of 62 meters; groundwater 2 is 59 meters whileleachate pond is positioned 68 meters above sea level. The contamination of the wells could be
hardly associated with leachate percolation, however, the surface runoff during precipitation whichruns over the groundwater sites could possibly contaminate the wells and may be aggravated by
the improper practices like laundering clothes, washing and bathing near the source by the local
water users. Mor (2005) emphasized in his study on the strong relationship between depth anddistance from landfills with groundwater samples. Water samples taken from wells adjacent to thelandfill were the most vulnerable to pollution and decrease of contaminants results as thehorizontal distance from landfills increase. In the same manner that, leachate concentration
increase with depth and decrease with increasing water addition. In Balaoan sanitary landfill, thegroundwater samples though adjacent to the study area, were found not contaminated with toxic
chemicals. Table 2 shows the summary results of the leachate water during the 1st and the second
sampling and the corresponding DENR Administrative Order(DAO) No. 35, Class C standards.
Table 2: Results of Leachate Water
Parameters, units
pH
Chemical Oxygen demand,mg/L
Total nitrogen,mg/L
Cadmium, mg/L
Chromium,mg/L
Copper, mg/L
Lead, mg/L
Mercury,mg/L

st

1 sampling
6.6
88
6.0
<0.006
<0.02
<0.01
<0.05
<0.0001nd

2

sampling
8.8
39
<1.0
<0.006
<0.02
<0.01
<0.05
<0.0001

DAO 35, Class C stds
6.5-9.0100--0.05------0.5
0.005

Source: CRL Environmental Laboratories, Inc., 2015

As gleaned from the results, pH of the leachate water revealed slightly basic in the second
sampling. The types of wastes may have made the change of pH as well as the decomposition
which may have become faster due to intense heat. In here, the organic and inorganic materials
were converted by anaerobic microorganisms to methane gas and other products such as
ammonia and sulphates depending on the type of wastes present. From the waste data (EMBDENR, 2013) Balaoan Sanitary Landfill generates 2.0 cu.m of wastes/ day. The Chemical Oxygen
Demand (COD) result obtained is below the regulatory limit of 100 mg/L. COD is a measure of theoxygen-depleting capacity of waste water and is equivalent to the amount of oxygen needed tooxidize the pollutants. Noticeably, water hyacinth covers the leachate pond. In the study conductedby Maharjan and Ming (2012), water hyacinth has the potential to treat waste water. Results of
their studies showed reduction of pollutants/nutrients particularly in the concentration reduction in
BOD, Total Nitrogen, Total Phosphorous, and Fecal Coliform. The results of this study showed34

similar results. The concentration of cadmium, chromium, copper, lead and mercury are way below
the regulatory limits and this implies that the leachate contains very minimal toxic metals that would
contaminate the groundwater. Further, this implies the good waste management practices
implemented by the local government units where wastes are being segregated before land filling.
The LGU has also a bio reactor installed in their material resource Facility (MRF) for compostingbiodegradable wastes.
Summary and Findings
1. The physicochemical parameters such as pH, temperature, turbidity, conductivity, total
dissolved solids, nitrates, total nitrogen, and total phosphorous conformed to the water
quality standards set by PNSDW.
2. Total and fecal coliform counts do not conform to corresponding PNSDW limits
3. The Chemical Oxygen Demand and concentrations of the toxic metals such as cadmium,
chromium, copper, lead, and mercury are far below the allowable limit.
Conclusion and Recommendation
1. Based on the obtained results, biological parameters such as total and fecal coliforms
results of the groundwater samples from both sampling sites did not conform to the water
quality standards set by PNSDW, thus, not advisable for human consumption. It isnecessary that water taken from the wells be properly treated either by boiling of water,
chlorination or water purification. pH of the water samples should be closely monitored forpotential health risks associated to acidic water.
2. The conductivity of the groundwater samples from both stations showed appreciable values
which when ignored may lead to undesirable water quality not fit for human consumption.
3. The Local Government Unit (Municipality of Balaoan) should continue its good waste
management practices of segregating wastes before land filling for reduction ofcontaminants especially the toxic metals that would be carried through surface water runoff.
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