Tag Archives: Water Quality

Irrigation Water Quality Assessment of Industrial Effluents Used for Irrigating Crops in Semi-arid Ecological Zone of Nigeria (Published)

Provision of quality treated wastewater effluents in form of irrigation water will potentially be an option to augment the water needs in agricultural irrigation. However, if the effluents did not meet the irrigation quality standards, their application will be detrimental to the receiving soils, consequently leading to soil and crop quality deterioration.  The aim of this study is to assess if Sharada industrial effluents are fit for irrigation application. The irrigation water quality assessment was carried out in three phases (Phases I, II and III) of the industrial locations. Findings indicated that the concentration of the major key irrigation water quality parameters; Electrical conductivity (EC), pH, Exchangeable sodium (Na), Calcium (Ca), Magnesium (Mg) and Total dissolved solids (TDS) were of good quality and suitable for irrigation regardless of phases.  However, the concentration of bicarbonate (HCO3), Chlorides (Cl), Potassium (K) and Nitrate (NO3-N) values detected in the samples were 488, 305, 305meq/l, 177.50, 159.75, 124.25meq/l, 18.99, 17.72, 13.50mg/l, and 119.09, 59.54, 31.53mg/l respectively. These values were high and of poor quality, thus, unfit for irrigation. Moreover, NO3-N and HCO3 in all irrigation effluents recorded high significant difference (P<0.05) in phase I compared to other phases while, Cl and K were highly significant (P<0.05) in phases I and II in comparison to phase III. Overall, the result when tested for irrigation quality compliance using International Standards revealed that compliance was achieved with reference to pH, EC, Na, Ca, Mg and TDS, while noncompliance was recorded for other irrigation water quality indices indicating that the effluents will be suitable for irrigation under careful, adequate and very effective proper management including improved irrigation system and schedule, soil with good permeability, infiltration and internal drainage, and use of good salt tolerant crops. The importance of this research lies in the fact that the effluents could not be a reliable and effective potential source of irrigation water rich in nutrients capable of increasing soil fertility and crop quality as is the practice of the farmers in the area.

Keywords: : Irrigation, Effluents, Soil Quality, Water Quality, crop quality

Water Quality and Phytoplankton as Indicators of Pollution in Ibuya River (Published)

Ibuya River runs across the Old Oyo National Park and there is paucity of information on the limnology of the river. In order to assess the status of the river, phytoplankton and water quality were examined during the study period of September 2012 to February 2014 at four sampling stations. A total of 45 species of phytoplankton belonging to four families were identified. The most representative family in terms of species richness was Bacillariophyceae (25 species), followed by Chlorophyceae (9 species) and Euglenophyceae (8 species) and the least dominant is Cyanophyceae with 3 species. Water temperature was 24.73 ± 0.21°C, pH was 7.57 ± 0.04 and dissolved oxygen (DO) was 4.43 ± 0.15 mg/L, conductivity was 140.83 ± 5.60 µS/cm, TDS was 98.11 ± 3.80 m/L. Cadmium (Cd), Lead (Pb) and Phosphate (PO₄) exceeded the permissible limits for surface water (0.003, 0.01 and 3.5 mg/L) respectively. The water quality and phytoplankton species composition of the river showed that allochthonous input from activities within and outside the park has subjected the ecosystem to pollution pressure.

Keywords: Anthropogenic Activities, Ibuya River, Phytoplankton, Water Quality, pollution indicators

Assessment of heavy metals concentration in crude oil contaminated water samples of three communities of Ikpokpo, Atanba, and Okpele-ama of Gbaramatu Kingdom, along the Escravos River in Warri South West Local Government Area of Delta State, Nigeria (Published)

Background: Water plays a significant role in maintaining the human health and welfare. Increase in industrialization and various human activities have recently increased the pollution of surface water and ground water (WHO, 1997). The aim of this study was to carry out the analysis of the specified heavy metals present in the crude oil contaminated water samples obtained from six different crude oil contaminated sites of three communities of Ikpokpo, Atanba and Okpele-ama of Gbaramatu Kingdom along the Escravos River in Warri South West L.G.A of Delta State, Nigeria, and to determine their health effects on the affected communities aforesaid. Standard analytical method (Atomic Absorption Spectrophotometer – (AAS) Analyst 400 model) was used to carry out the analysis. Table 1, presents the WHO maximum permissible limits of some specified heavy metals in normal drinking water sources. Also, the results of the two samples analysed were all being presented from table 2 to 5 as being indicated in a tabular form. Upon comparison, between the mean values of the crude oil contaminated samples (table 5), with the WHO permissible values (table 1) and normal water samples analysed (table 3), It was found out that the crude oil contaminated water samples values were all above the WHO maximum permissible limits of heavy metals concentrations in normal drinking water sources (WHO, 2003, 2005 and 2011).Therefore, there is need for remediation of the crude oil contaminated water samples to the level of WHO standard guidelines.

Keywords: Contamination, WHO, Water Quality, crude oil spills, heavy metals analysis

River Water Quality Assessment and Suitability for Irrigation in Northern Sudan Savanna, Ecological Zone of Nigeria (Published)

Good river water quality management and reusing the water appropriately in irrigation agriculture can decrease complete soil and crops toxicity, and serve as a potential feasible options to potable water as well as improvement of natural water resources shortages. This study was carried out between May and July, 2019 to investigate the discharge and irrigation reuse quality of Wudil River effluents in Kano State, Nigeria. The research was conducted in three locations of the river; locations A, B and C respectively. Water quality parameters; pH, COD, BOD5, nutrients (NO3-N, NH4-N and PO4-P), EC and SS were determined in different water samples obtained from the different locations. Data obtained were subjected to statistical analyses of variance (ANOVA). No significant variations (P>0.05) existed in all the chemical variables among the sampled locations. Comparison of the investigated parameters at the various locations of the river with the standard limit of discharge and irrigation reuse revealed that all the locations achieved compliance except for NH4-N and PO4-P variables that polluted the river using Food and Agricultural Organization (FAO), World Health Organization (WHO), United States Environmental Protection Agency (USEPA) and other related international standards. Hence, the need for a drastic move towards both discharge and irrigation water quality improvement of the river as well as environmental conservation through sustainable development and cleaner technology approach within the research area is highlighted.

Keywords: : Irrigation, River effluents, Soil Quality, Water Quality, wastewater

Comparative Analysis of Water Quality from Harvested Rain and Borehole Water in Owerri-West, Imo State (Published)

The growing global population in a bid to solve the challenge of water shortage has resorted to groundwater and rainwater considering their benefits. The aim of this study was to assess and compare the quality of harvested rainwater and underground water (borehole) in Owerri-west in order to ascertain their portability in the light of WHO (2010) drinking water standard. Groundwater and rainwater samples were collected from Ihiagwa, Obinze and Nekede and analysed for physicochemical and microbial quality. These samples were analyzed using laboratory analytical techniques as recommended by World Health Organization and American Public Health Association. The result from the analysis showed that the Heterotrophic Bacterial Counts (cfu/ml) of water samples were BH (6.58%), Aluminum (11.84%), Zinc (19.74%), Asbestos (28.95%) and Thatched (32.89%). Out of the four bacteria (Escherichia coli, Enterococcus faecalis, Bacillus subtilis and Staphylococcus epidermis) observed in all the water samples, Escherichia coli had the highest number of occurrence of 126(82.89) cfu/ml. All the physicochemical parameters analyzed conformed to the recommended standard value apart from pH value from borehole, and the rainwater sample from thatched roofing sheet with turbidity (10.3 NTU), objectionable taste and odour, and a general appearance that was not clear. The results observed showed the sequence of quality of groundwater and rainwater as Borehole > Aluminum > Zinc > Asbestos > Thatched.  Generally, groundwater was more potable than harvested rainwater within the study area. This study however suggests that drinking water sources should be properly treated especially harvested rainwater prior to consumption using appropriate method in order to reduce the occurrence of waterborne disease.

Keywords: Bacteria, Physicochemical, Water Quality, water borne diseases

Assessment of Physicochemical parameters in crude oil contaminated water samples of three communities of Ikpokpo, Atanba, and Okpele-ama of Gbaramatu Kingdom, along the Escravos River in Warri South West Local Government Area of Delta State, Nigeria (Published)

Background: Water plays a significant role in maintaining the human health and welfare. Due to increase in industrialization, urbanization and various human activities has increase the pollution of surface water and ground water (WHO, 1997). The aim of this study was to carry out the physicochemical analysis of crude oil contaminated water samples obtained from the crude oil contaminated sites of the three communities of Ikpokpo, Atanba and Okpele-ama of Gbaramatu Kingdom of Warri South West L.G.A of Delta State, Nigeria and determine its effects on the aforementioned communities and also to compare the results obtained with other sources of normal drinking water. Results: WHO maximum permissible limits for all the parameters are being presented in Table 1. The results of all the physicochemical parameters analysed using different analytical methods can be summarised as follows: From Table 3, pH of water has mean of 6.8, standard deviation of ±0.147 and the range value is from 6.0 to 7.0. Also, from table 5, the mean is 5.7 and range value is from 5.2 to 6.1, with standard deviation of ±0.354 respectively. Decrease or increase in pH values of water below or above the WHO permissible limits can result in a serious health related complications such as vomiting, cholera, diarrhoea, kidney and liver diseases, stomach cramps and nausea upon consumption. In table 3, the average value is 1.39NTU, the standard deviation is ±0.103NTU and the range is from 1.21NTU to 1.5NTU. The range of the results in Table 5 is from 27NTU to 40NTU and the mean or average value is 31NTU with standard deviation ±3.488NTU. Increased turbidity level in water is not desirable and can lead to some health related issues such as gastrointestinal diseases e.g. perianal abscesses, colitis. More so, from table 3, the mean value of temperature is 28.3˚C and the range is from 28oC to 28.7oC with standard deviation of ±0.248˚C.  Furthermore, the results in table 5, has the standard deviation of ± 1.472˚C, the mean value is 32oC with ranges from 30˚C to 34oC respectively. The average value of electrical conductivity from Table 3 is 187µs/cm and the range is from 180µs/cm -193µs/cm with standard deviation of ±5.269 µs/cm, meanwhile, in Table 5, the standard deviation is ±3889.3µs/cm, average value of electrical conductivity is 24197.2µs/cm and the range is from 16871 to 27300µs/cm. These values are higher than the maximum permissible limits of electrical conductivity in water. The range of TSS values in Table 3 is from 17mg/L to 23mg/L and the mean value is 20.3mg/L with standard deviation of ±2.160mg/L. Upon comparison with the values of TSS from table 5, with mean 35.8mg/L, while the range is from 31mg/L to 40mg/L and standard deviation of ±1033.9mg/L, which were all above the ranges of WHO TSS limit in normal drinking water. This can serve as a growth medium for bacteria and other microorganisms. TDS in Table 3 has the mean value of 118mg/L, the range values from 110mg/L-125mg/L and the standard deviation is ±5.138. Also from table 5, the mean value of 17796.7mg/L and the ranges from 16400mg/L to 19500mg/L with standard deviation of ±2.898mg/L. High content of TDS values produces an unwanted taste and diluted colour in water, indicating that the water is mineralised as such; upon consumption of the water with high TDS limits, can result in health related complications like kidney and heart diseases. Conclusion: On the basis of findings, it was concluded that the crude oil contaminated water samples collected from the crude oil contaminated sites of the three communities aforesaid were all above the permissible limits (WHO, 1997). Meanwhile, the normal drinking water samples obtained within Kano Metropolis, used in benchmarking were consistent with WHO standards.

Keywords: Contamination, Physicochemical Analysis, WHO, Water Quality, crude oil

Status of Discharged Abattoir Effluent and Its Effects on the Physico-Chemical Characteristics of Orogodo River, Delta State, Nigeria (Published)

The discharge of untreated wastewater into waterbodies results in water quality deterioration of the receiving waters. This study assesses the impact of abattoir wastewater discharge on the water quality of Orogodo River in Nigeria. Effluent discharges and water samples were collected from river at six points over a 6-month period. Physicochemical analyses were conducted using standard methods. The pH was within a fixed band of 5.56 – 8.04. The downstream biochemical oxygen demand of the receiving river water increased significantly to 75% in July and up to 192% in December. Suspended solids, chemical oxygen demand, total nitrogen and total phosphorus followed a similar trend. Dissolved solids, dissolved oxygen, nitrate, also increased appreciably. The downstream levels of these parameters were higher than their corresponding upstream values, indicating that the discharge of the abattoir wastewater into the river has negatively impacted the river water. The dilution of the waste in the river water was not enough to reduce them to acceptable levels. This study demonstrates that abattoir wastewater impacts Orogodo River water negatively. The abattoir effluent did not meet the National standard for effluent discharge into the environment leading to cross pollution of the receiving water based on the parameters investigated. This therefore, calls for the need to put an effective wastewater treatment and monitoring system in place to enforce existing legislations to curb water pollution and to safeguard both the environment and human health.



Keywords: Abattoir, Impact, Orogodo, Pollution, Water Quality, physico - chemical, wastewater

A classification model for water quality analysis using decision tree (Published)

A classification algorithm is used to assign predefined classes to test instances for evaluation) or future instances to an application). This study presents a Classification model using decision tree for the purpose of analyzing water quality data from different counties in Kenya. The water quality is very important in ensuring citizens get to drink clean water. Application of decision tree as a data mining method to predict clean water based on the water quality parameters can ease the work of the laboratory technologist by predicting which water samples should proceed to the next step of analysis. The secondary data from Kenya Water institute was used for creation of this model.  The data model was implemented in WEKA software. Classification using decision tree was applied to classify /predict the clean and not clean water. The analysis of water Alkalinity,pH level and conductivity can play a major role in  assessing water quality. Five decision tree classifiers which are J48, LMT, Random forest, Hoeffding tree and Decision Stump were used to build the model and the accuracy compared. J48 decision tree had the highest accuracy of 94% with Decision Stump having the lowest accuracy of 83%.

Keywords: Data mining, Decision Tree, Water Quality, Weka Tool, classification model

Physicochemical and Microbiological Characteristics of Water Samples from the Borgu Sector of Kainji Lake National Park, Nigeria (Published)

The quality of water resources in any ecosystem provides significant information about the available resources for supporting life in such ecosystem. The study therefore assessed the physicochemical and microbiological characteristics of water samples from the Borgu Sector of Kainji Lake National Park, Nigeria. The study was carried out at Borgu sector of KLNP purposively selected based on the availability of perennial waterholes. Water samples were collected from four waterholes for two seasons (dry and wet). Water samples were subjected to physicochemical [temperature, pH, total dissolved solid, electrical conductivity, total suspended solids, dissolved oxygen (DO), nitrate, chloride, phosphate, sulphate, biological oxygen demand and chemical oxygen demand (COD)] and microbiological (total coliform and fungal counts) analyses using standard methods. Data collected were subjected to descriptive statistics and T-test at α0.05 and compared with WHO permissible limits. The result showed that DO and COD levels of all the water samples were above the WHO guideline while there were significant seasonal variation in the values of temperature (t=4.93), EC (t=2.46), TDS (t=2.33), nitrate (t=3.66), chloride (t=4.91) and COD (t=4.23) in the waters sampled across the seasons of sampling. Salmonella / Shigella and Staphylococcus aureus were observed to be absent while the total coliform and fungi counts were observed to be higher than the WHO permissible limit for drinking water. The presence of thermo-tolerant such as Klebsiella sp and Enterobacter sp observed in the study may be an indication of faecal contamination. Periodical monitoring of the river water quality in Kainji Lake National Park is required to protect drinking water resources, encourage recreational activities and provide a good enabling environment for wildlife.

Keywords: Anthropogenic Activities, Kainji Lake National Park, Seasonal variation, Water Quality

Surface Water Pollution of the Mediterranean Sea by New Damietta Harbor, Nile Delta, Egypt (Published)

The Damietta Harbor is situated near the eastern branch of the River Nile estuary, 250 km east of Alexandria. Marine eutrophication is mainly an inshore problem that affects lagoons, harbors, estuaries and coastal areas adjacent to river mouths. Although the main body of the Mediterranean Sea as a whole is not yet seriously threatened by eutrophication, areas of pronounced eutrophication are expanding in the Mediterranean.  The main objective of the study is to characterize water, soil and sediment that will be dredged to determine their suitability for placement in either upland, an offshore disposal site, or at an existing beach for re-nourishment, and to observe the effect of the harbor on surface water pollution of the Mediterranean Sea. The dredging operations in Damietta Port sediment, soil and water investigations were conducted to understand the possible disposal or re-use considerations. The following samples were investigated:

  • Offshore stations representing existing, proposed and reference stations,
  • Sediment cores within the port and approach channel,
  • Sediment grabs within the port and approach channel, and
  • Soil borings from terminal basin.

Also, the water quality of different basins inside the harbor and in the marine waters at the mouth of the harbor was investigated.  Water samples were analyzed for parameters indicating the chemical and biological quality of the harbor environment.  In general, the water, soil, and sediment quality in the study area were within the permissible levels for physical-chemical parameters of marine water, although some metals were considerably higher than the background levels. In total, the off shore qualities were within the limits in all locations that are not hazardous to the Mediterranean Sea environment.

Keywords: Dredging Damietta Harbor., Environmental Analysis, Mediterranean Sea Pollution, Water Quality

Modelling the Impact of Spilled Oil at Nigeria Liquefied Natural Gas (NLNG) Jetty on Surface Water Quality (Published)

This study was to model the impact of oily wastes discharge and other contaminants to the river at Nigeria Liquefied Natural Gas (NLNG) Base Jetty. The methodology of the study include review of relevant literatures, field measurement of hydraulic properties and laboratory analysis of physico-chemical parameters of the stream from eight (8) sampling stations covering the dry and rainy seasons. The results obtained from the analysis showed that the DO varied from 2.51mg/l to 4.22mg/l and BOD5 varied from 4.31mg/l to 12.42mg/l along the stream. The re-aeration coefficient Kr of the stream varied from 0.018d-1 to 0.340d-1. The model developed from the values of Kr observed and Kr predicted showed strong correlation with a coefficient of correlation of 0.93. The observed Kwas compared with predicted Kr, Gualtieri, Churchill, Agunwamba, O’Connor and Dobbins,  and Ugbebor which gave standard errors of 0.0404, 0.1290, 0.1860, 0.0451, 0.1868 and 3.1118 respectively.. This showed that the study Kr model performed better than the other Kr models. The self-purification factor of the study river gave 0.36, indicating that the stream is sluggish and polluted. The study recommended close monitoring of discharges and activities at Nigeria Liquefied Natural Gas (NLNG) Base Jetty.

Keywords: Nigeria Liquefied Natural Gas, Spilled Oil, Water Quality

A Visibility Study for Choosing the Dug Wells Alternative versus Deep Wells for Water Supply (Published)

While access to water remains an essential issue in arid and semi-arid regions, aquifers have the potential to help millions of people out of a reliable source of water. Boreholes are increasingly advocated as a safe and cost-effective substitute to mechanized drilling, as well as to traditional excavation methods. The main target of the present study is to evaluate and locate the possibilities of water resources occurrence in the proposed area, indicate whether to use a deep well or a shallow dug well. The study consists of three steps; the first step was drilling the dug well after data collection and allocates the suitable well location. The second step included a pumping test for the productive well lies at Nabq- Sharm El-Sheikh – South Sinai with a depth of 114 meters which was done. The third step included a water quality monitoring for the well, as the samples was taken each 12 hours for 3 days from the existing well. It is concluded that for the presented model of using large diameter wells instead of small diameter wells has shown insignificant improvement in the well yield in the study area. For the well under consideration, it is recommended to operate this well for a pumping rate of 50 m3/hr (for 24 hours per day) to maintain the long-term drawdown at 3 meters in addition to the well losses which is less than 0.5 meter.

Keywords: Deep Well, Development Area., Hydrogeology Study, Pumping Test, Water Quality, Water Resources

Impact of Abattoir Waste on the Water Quality of Amilimocha River Asaba, Delta State (Published)

Water pollution has been a major environmental problem globally. This study investigated the effects of abattoir waste on the water quality of Amilimocha River in Asaba, Delta State, Nigeria. Water samples were collected from three sampling locations upstream L1, point of discharge L2, downstream L3, and a control sample L4. Samples were immediately taken to the laboratory for standard analysis. Salinity varied from (0.01 – 0.06%), conductivity (56.70 – 85.10µs/cm), DO (7.80- 8.55mg/L), BOD  (3.00 – 6.21mg/L), COD (8.95 – 15.5mg/L), TDS (20.00 – 53.00mg/L), turbidity ( 23.00 – 41.50 NTU), NO3 (0.16 – 0.35mg/L), P042-  ( 0.02 – 0.6mg/L), temperature ( 26.00 – 29.10oC), pH ( 6.50 – 8.20) and coliform bacteria counts (10.00 – 50.00 cfu/100ml). There was significant heterogeneity in mean variance of the water quality parameters across the sampling locations [F(31.09)>Fcrit(3.94)] at P<0.05. A further structure detection group means revealed that all the parameters contributed to the observed heterogeneity. Mean concentration of DO and BOD (8.22  0.73 and 5.10 0.37mg/L) respectively exceeded the World Health Organization 6.80 and 4.0mg/L maximum permissible limits for aquatic life. Abattoir wastes should be properly treated before disposal and freshwater systems should not serve as recipients  of untreated  abattoir waste.

Keywords: Abattoir Waste, Amilimocha, Asaba., Human Health, Water Quality, river

Physico-Chemical Evaluation of Groundwater in Ogbia, Bayelsa State, Nigeria (Published)

This study evaluates the physico-chemical properties of groundwater in Ogbia, Bayelsa State, Nigeria.  Standard field and laboratory methods were followed. The results of the study revealed that the pH value ranges from 6.4 to 7.1 with an average of 6.86 indicating a slightly acidic condition. The concentration level of iron in the study area ranges from 0.1mg/l to 4.2mg/l with a mean value of 1.89mg/l. 13.3% of iron in sampled locations satisfy the World Health Organization (WHO) and Nigerian Standards for Drinking Water Quality (NSDWQ) highest desirable level of 0.3mg/l. The concentration of calcium ranges between 3.0mg/l to 13.1mg/l, with a mean value of 8.83mg/l, while magnesium concentration was from 1.8mg/l to 9.0mg/l, with a mean value of 5.6mg/l. The concentration level of phosphate in the study area ranges from 0.02mg/l to 0.19mg/l, with a mean value of 0.12mg/l.  Chloride concentration level in the sampled locations was between 10mg/l to 39mg/l, with a mean of value of 23.8mg/l, all the values recorded were within the permissible WHO and NSDWQ standard of 250mg/l.  The low concentration level of chloride in the area indicates that there is no salt water intrusion, hence all the locations have freshwater. The cations were in order of abundance as Na+ > Ca 2+ > Mg 2+ > Fe 2+ > Mn 2+, while anions were in the order of abundance as SO4 > Cl > NO3 > F > NH3 > PO4. Piper Trilinear Diagram for the study area showed that there were mixtures of two types of water with variable concentrations of major ions. These were sodium-chloride type and sodium- sulphate type of water, an indication that the water was from a marine source. Based on the result from this study, there is the need for regular ground water quality monitoring and effective management strategies in the area.

Keywords: Contamination, Freshwater, Groundwater, Ogbia, Water Quality, major ions

Effects of salinity and hardness on the growth of Nile tilapia (Oreochromis niloticus) in Northern Punjab region of Pakistan. (Published)

The tolerance of salinity and hardness was checked on the growth and survival of Nile tilapia (Oreochromis niloticus) in National Agriculture Research Council (NARC) Islamabad. Fry of the Tilapia measuring between 2.5cm to 2.9cm in total length and weighing between 0.435g to 0.603g (Body Weight BW) were used for the salinity and hardness treatment. Different levels of salinity from 0-15ppt were developed for the three months. 100 % survival rate was observed in 0-7.5ppt while in 12.5ppt and 15ppt all the fish died. Salinities between 0-10ppt were endured by the fish however the most appropriate salinity level was 5ppt on which maximum growth was recorded. For hardness treatment different concentrations of 350mg/lit, 450mg/lit, 550mg/lit and 650mg/lit of CaCl2 were used. No mortality was observed in this case and the most preferred concentration on which the fish showed maximum growth was 550 mg/lit.

Keywords: Growth Performance, Survival, Water Quality, saline resistance, tilapia growth

Study on the Chemical and Biological Status of Malwatu Oya Basin, Anuradhapura in Sri Lanka. (Published)

Water pollution is a serious problem to the entire world. It threatens the health and wellbeing of humans, plants, and animals. With the advancement of communications and trade due to industrialization, accidental and purposive waste dumping, and uncontrolled use of water sources have contributed to the problem of water pollution in both surface water and the ground water. This study was mainly concerned with the evaluation of water quality of Malwathu Oya and its four basin tanks in the dry zone of Sri Lanka namely Nuwara wewa, Tissa wewa, Nachchaduwa wewa and Mahakanadarawe wewa in the Anuradhapura district using some selected water quality parameters. Malwathu Oya has been using as a source of drinking water for Anuradhapura. Eutrophication through the process of nutrient enrichment of stagnant waters due to urbanization & chemical added agricultural practices has been considered as the significant cause for water pollution in these areas. They cause algal blooms and release of toxic substances from species like cyanobacteria. Low Secchi Depth value and high chlorophyll a concentration indicate eutrophic nature of the Nuwarawewa and Tissawewa Lakes in dry periods. Malwathu oya too showed reasonably high Chlorophyll content during the same period. High nutrient loading was observed through the growth of phytoplankton species. Cylindrospermopsis raciborskii was the most dominant species recorded in the present study and Microcystis aeruginosa, Microcystis incerta, Pediastrum duplex. Merismo pediatenuissima, Melosira granulate and Diatomaelongata were also recorded from Nuwarawewa and Tissawewa during the study period. With respect to Physical and chemical parameters, very high turbidity, high nitrogen compounds ( Ammoinia, Nitrate, Nitrite), phosphate, total suspended solids, dissolved oxygen, chemical oxygen demand, biological oxygen demand were recorded in Nuwarawewa and Tissawewa due to the influence of human activities such as recreational , dumping wastes and agricultural practices. However data indicate that Nachchaduwa and Mahakandarawa lakes are well protected from above threats. At the same time Malwathuoya stream also showed the same kind of pollution pattern causing more critical situations for water treatment and water quality aspects. Therefore, an effective Lake Management and Lake monitoring programmes with integrated catchment management have to be adopted and it is a prior necessity in planning of the management practices of the catchments to get first hand information through this kind of research on these lakes.

Keywords: Coliforms, Eutrophication, Malwathuoya River Basin, Phytoplankton, Urbanization, Water Quality