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Evaluation of surface and groundwater quality in Pattiwila area

ByL.N.W. PereraEM/2007/029IntroductionQuality of surface and groundwater is important due to human consumption and other usage of water demand is increasing.

Consume and usage of poor quality of water can leads to human infections, birth defects, disturbances to flora and fauna etc.

L.N.W. Perera - EM/2007/02922MotivationWater quality of Pattiwila canal can be affected by point and non point sources of pollution in the catchment area including ;Sapugaskanda oil refinerySapugaskanda diesel power stationLaugfs holdings limited and other industrial activitiesAgricultural practices andDomestic discharges etc.

L.N.W. Perera - EM/2007/02933Motivation cont..Drinking water intake of Kelani right bank water treatment project of NWSDB is located at the Kelani River just after the Pattiwila cannel connected to Kelani River

L.N.W. Perera - EM/2007/0294ObjectivesTo determine the surface water quality along the Pattiwila cannel to Kelani River to evaluate the spatial and temporal variation of water quality parameters.

To determine the groundwater quality in domestic water wells to evaluate the spatial and temporal variation of water quality parameters.

L.N.W. Perera - EM/2007/0295Objectives cont..To determine relationship between monthly rainfall and measured water quality parameters of surface water and groundwater.

To compare the surface water quality and groundwater quality with relevant water quality standards given by CEA.

L.N.W. Perera - EM/2007/0296Materials and Methods7Study area

Catchment of the Pattiwila canal8Sampling sites

9Data Collection from sampling sitesPrimary data collectionMethod:Grab sampling/ Composite sampling- Using depth sampler

Duration:Once a month for four months from March 2012 to June 2012

Water quality measurements:14 water quality parameters 10Secondary data collectionMonthly rainfall data Angoda mental hospital rain gauging station (station number 16) from the Department of Meteorology, Colombo, Sri Lanka.

Water quality standardsWater treatment plant at Ambathale and Central Environmental Authority (CEA) at Baththaramulla

L.N.W. Perera - EM/2007/02911Data AnalysisWater quality analysis were done in-situ and laboratory in the NWSDB water treatment plant laboratory at Ambathale and special laboratory in Department of Zoology and Department of Chemistry.

Statistical analysis were done by using MINITAB software (version 14)

L.N.W. Perera - EM/2007/02912This statistical procedure was repeated for five sampling sites of surface water and four sites of groundwater during the study period.

12Results and Discussion13Spatial variation of water quality parameters in surface water14Spatial variation of water quality parameters in surface water15 Conductivity Salinity TDS AlkalinitySpatial variation of water quality parameters in surface water 16 Na+ Cl- BOD5 CODSpatial variation of water quality parameters in surface water Oil and grease DOL.N.W. Perera - EM/2007/0291717Temporal variation of water quality parameters in surface water18Temporal variation of water quality parameters in surface water Oil and grease TurbidityL.N.W. Perera - EM/2007/0291919Spatial variation of water quality parameters in groundwater20Spatial variation of water quality parameters in groundwater Conductivity Salinity TDS Na+21Spatial variation of water quality parameters in groundwater22 Oil and grease TurbidityTemporal variation of water quality parameters in groundwater2324 COD Cl-Temporal variation of water quality parameters in groundwater25Temporal variation of water quality parameters in groundwater BOD5 Oil and greaseRelationship with rainfall26

Salinity in R1Relationship between rainfall and water quality parameters in surface water

Salinity in R2

TDS in C2

TDS in C327

pH in C3Relationship between rainfall and water quality parameters in surface water

BOD5 in C1

Apparent colour in C328

Salinity in W2Relationship between rainfall and water quality parameters in groundwater

Na+ in W2

Na+ in W4

Oil and grease in W229Comparison with water quality standards30Surface water quality in Pattiwila canal and Kelani River31Variation of BOD5with surface water quality standards

L.N.W. Perera - EM/2007/0293232Variation of oil and grease with surface water quality standards

L.N.W. Perera - EM/2007/02933Groundwater quality in domestic water wells34Variation of oil and grease with groundwater quality standards

L.N.W. Perera - EM/2007/02935Variation of COD with groundwater quality standards

L.N.W. Perera - EM/2007/02936Possible shortcomingsThe study was limited to four months of study period and sample collection was done once a month with respect to availability of time, resources and equipment within the laboratory.

Biological monitoring including investigation of macro-benthic fauna and associated sediment analysis is not considered.

L.N.W. Perera - EM/2007/02937The research should be repeated with the higher frequency of data collection in longer period of time including other important physico-chemical parameters namely phenol, PAHs, NH4+, NO3-, PO43-, SO32-, SO42-, CN-, metals etc. in order to get better interpretation of water quality of the study area.

Monthly rainfall data were obtained from Angoda mental hospital rain gauging station (station number 16) and it was assumed that rainfall is evenly distributed within the study area. It will be important to have some more rain gauging stations around the study area to get better rain fall distribution in the study area

In the present study, sample collection was done once a month for four months of study period hence statistical tests were performed with limited conditions for the data analysis. This can be affect to the validity of the statistical test.

37ConclusionWater quality of Pattiwila canal is above the standards of irrigation, agricultural and as raw water for public water supplies due to higher BOD5 and oil and grease levels.

Water quality Kelani River is also above the standards of use as raw water for public water supplies, irrigation and agricultural due to higher oil and grease levels.

Water quality of groundwater in domestic wells is above the standards of drinking purposes without proper treatment due to higher COD and oil and grease levels.

38L.N.W. Perera - EM/2007/029RecommendationsGravity separation and using organoclays for water purification before consumption.

NWSDB has to implement oil and grease treatment unit in order to provide good quality drinking water to the consumers.

Bioremediation and phytoremediation techniques and testing on sorbent materials are recommended to reduce high amount of oil and grease, BOD5 and COD present in the waste water as well as soil of the catchment area.

39L.N.W. Perera - EM/2007/029Thank You..!L.N.W. Perera - EM/2007/02941Measured water quality parametersWater quality ParameterStandard method and instrumentsTemperature (C)YSI Environmental Model 556 water quality checker (USA)

pHConductivity (S/cm)Salinity (ppt)TDS ((mg/L)Apparent colour (Hazan Units)Visual comparison method using Lovibond Nessleriser (Model No. 2150, UK)Turbidity (N.T.U.)Nephelometric method using Portable turbidity meter (Model 2100P, Hach Company, USA)DO (mg/L)Winkler methodBOD5 (mg/L)Winkler methodAlkalinity (mg CaCO3/L)Potentiometric titration methodCl- (mg/L)Argenometric methodCOD (mg/L)open reflux methodOil and grease (mg/L)Partition-Gravimetric methodNa+ (ppm)Atomic Absorption spectrometry using Atomic Absorption spectrometer (GBC 932 plus) with air- acetylene flame4242Statistical AnalysisChanges of water quality parameters between the sampling sites during the study period Two-way ANOVA at 95% confidence level using MINITAB (version 14)

Spatial Variation of water quality parametersOne-way ANOVA followed by Tukeys test at 95% confidence level using MINITAB (version 14)

Temporal Variation of water quality parameters One-way ANOVA followed by Tukeys test at 95% confidence level using MINITAB (version 14)

L.N.W. Perera - EM/2007/02943This statistical procedure was repeated for five sampling sites of surface water and four sites of groundwater during the study period.

43Selecting sampling sitesPreliminary survey to identify sampling sitesTransect walks along the Pattiwila canal

Existing information about water pollution within the study area by NWSDB

Five sampling sites - Surface water quality analysisFour sampling sites - Groundwater quality analysis

Surface water sampling sitesSampling site C1

Sampling site C2Sampling site C3

Surface water sampling sitesSampling site R1Sampling site R2

Groundwater sampling sitesSampling site W1Sampling site W2

Sampling site W4Sampling site W3Temporal variation of water quality parameters in surface waterConductivitySalinityTDSApparent colourAlkalinityDOBOD5 Temporal variation is not significantL.N.W. Perera - EM/2007/02948Spatial variation of water quality parameters in groundwaterTemperatureCODApparent colourAlkalinitySpatial variation is not significantL.N.W. Perera - EM/2007/02949Temporal variation of water quality parameters in groundwaterConductivitySalinityTDSTurbidityAlkalinityNa+Temporal variation is not significantL.N.W. Perera - EM/2007/02950Surface water quality in Pattiwila canal and Kelani RiverTolerance limits for the inland surface waters for use as raw water for public water supply (Sri Lanka Standard 722: 1985)

Inland water quality standards for irrigation and agriculture (category 6).

Turbidity Apparent colour Temperature pH

Temporal variation of water quality parameters in surface waterpHTurbidity

pHCl-

DO Temperature Apparent colour pHGroundwater quality in domestic water wellsSpecification for potable water part I- Physical and chemical requirement (Sri Lanka Standard 614: 1983)ConclusionAll the water quality parameters of surface water except water pH are spatially varied. Water temperature, COD, Na+, Cl-, pH, oil and grease and turbidity of surface water are temporally varied.

Water quality parameters of groundwater namely conductivity, salinity, TDS, Na+, Cl-, turbidity, DO, BOD5, oil and grease and pH are subjected to spatial variation and DO, Cl-, COD, oil and grease, temperature, pH, apparent colour and BOD5 are temporally varied. ConclusionpH of C3 sampling site, salinity of R1 and R2 sampling sites TDS of C2 and C3 sampling sites and BOD5 of C1 sampling site of the surface water shows positive relationship with rainfall.

Apparent colour of C3 sampling site of surface water, salinity of W4 sampling site, Na+ of W2 and W4 sampling sites and oil and grease content of W2 sampling site of groundwater shows negative relationship with rainfall.

Surface water quality parameterSampling SiteP valuer valueR2 valuepHC30.0020.99899.6%SalinityR1 and R20.003 and 0.0030.997 and 0.99794.4% and 94.4% TDSC2 and C30.019 and 0.0080.981 and 0.99296.2% and 98.4%BOD5C10.0120.98894.4%Apparent colorC30.028-0.97297.7%Relationship between rainfall and water quality parameters in surface water

Water quality ParameterSampling SiteP valuer valueR2 valueSalinityW40.003-0.99799.4%Na+W2 and W40.047 and 0.003-0.953 and -0.99790.8% and 99.4%Oil and greaseW20.020-0.98096.1%Relationship between rainfall and water quality parameters in groundwater

Tolerance limits for inland surface water for use as raw water for public water supply (Sri Lanka Standard 722: 1985)L.N.W. Perera - EM/2007/02962

Inland water quality standard for irrigation and agriculture (category 6)L.N.W. Perera - EM/2007/02963

Specification for potable water Part 1- Physical and chemical requirement (Sri Lanka Standard 614: 1983)

L.N.W. Perera - EM/2007/02964

L.N.W. Perera - EM/2007/02977