A Study of the Physico-Chemical and Biological Characteristics of Drinking-Water Quality from Different Points- of- Use in Shillong Polytechnic, Mawlai Kynton Massar and Mawlai Mawdatbaki, Shillong, Meghalaya

Introduction

Water is the most essential requirement of humans, plants and animals. It is the life blood of man, without which life on earth will cease to exist. Most human activities involve the use of water in one way or other. Although the surface of our planet is nearly 71% water, only 3% of it is fresh [1,2]. Of these 3% about 75% is tied up in glaciers and polar icebergs, 24% in groundwater and 1% is available in the form of fresh water in rivers, lakes and ponds suitable for human consumption [3-5]. Out of all water resource, groundwater is one of the important drinking water resources [6,7].

The quality of any body of surface or ground water is a function of either both natural influences and human influences [8]. Without human influences water quality would be determined by the weathering of bedrock minerals, by the atmospheric processes, and the deposition of dust and salt by wind, by the natural leaching of organic matter and nutrients from soil, by hydrological factors that lead to runoff, and by biological processes within the aquatic environment that can alter the physical and chemical composition of water. Declining water quality has become a global issue of concern as human populations grow, industrial and agricultural activities expand, and climate change threatens to cause major alterations to the hydrological cycle [9,10]. Climatic changes and unpredictable weather patterns of the world, is evident of the fact that water as a resource, is becoming scarce and declining [11]. Climate change in the last century has major ramifications albeit water quality in the world which can alter the ecological balance of the region in question which ultimately threatens the water-limited ecosystems of the world [12].

Contamination of water occurs in many ways and forms, like pollution, climate change, human interference, industrial activities, agricultural run- off, seepage from urban settlements, mineral infiltration from underlying rocks, shortage and scarcity of water, use of chemicals and pesticides, etc. Pollution, environmental factors and mostly human activities have contaminated surface water and groundwater sources making it unfit for drinking, cleaning, washing and irrigation [13,14]. Clean potable water is needed for the sustenance of life and for the health, hygiene and well being of humans, plants and animals [15,16].

Safe drinking water is a human right and a fundamental requirement for people to live a healthy life and it is essential for hygiene and disease control [17-19]. The World Health Organization emphasizes that access to safe drinking water is important as a health and developmental issue at a national, regional and local level [20,21].

Water quality has been the main focus in developmental studies in terms of health, industries, construction, households, and the well being and nature of a place and region.. With the quality of water deteriorating at a very rapid rate, the clamour for clean potable water is gaining momentum and the need for analysis of all water sources is demanding, so as to minimize the incidence of diseases and illnesses from water as a source.

The Bureau of Indian Standards serves as an easy reference to the quality of water and provides a predefined limit to all possible contaminants of the water in the country. The handbook on Water testing by Dr.R.N.Ray, as the chief editor, with his team of editors, from the Indian Institute of Science, Bangalore, gives us a clear and meaningful reference, to the standard methods of tests to be carried out with special reference being given to the experimental procedures and theoretical basis [22].

The Indian standards Drinking water specifications is a ready document that feeds us  with information on a compilation of research works done on the subject over fair period of time. Literature on water quality testing and analysis is of a considerable amount, that dates back to decades of research and development in the field, and updating knowledge and information that becomes resource for the scores of people pursuing their studies in the area.

Study Area

The study area of Shillong Polytechnic campus, and two localities surrounding it i.e. Mawlai Kynton Massar and Mawlai Mawdatbaki, have been identified for drinking water analysis, as different sources of Drinking water can be identified for these areas. The present water supply in Mawlai town is met through ground water (spring) and surface water (stream) sources. There are different sources of drinking water for Mawlai area, the Umsohlang Surface water stream, personal and private underground dug wells and tubewells, and Ground water spring.

There are two main agencies involved in organized drinking water supply in Shillong city, viz.

Public Health Engineering Department (PHED) and Municipal Corporation, Shillong. Among these, the Public Health Engineering Department (PHED) also supplies water to the Mawlai region, from the Mawphlang (Greater Shillong Water Supply Scheme).

The Umsohlang (Mawlai) and Mawphlang (Greater Shillong Water Supply Scheme) have design capacities of 3.4 and 34 MLD respectively, with treatment plants, having rapid sand filter for water filtration [23]. The treated water of Umsohlang (Mawlai), is stored in two storage cum service reservoirs located at MawlaiNonglum and MawlaiMotsyiar areas with the capacities of 0.55 ML and 0.025 ML respectively.

Mawlai town has a monsoonal types of climate, which is influenced by the North-East winter winds. Rainfall is mostly concentrated in the monsoonal (Summer) months, i.e. May to September, with frequent showers in and around the year. The temperature ranges from 25°C to 15°C during the summer season while during winter the maximum and minimum terperatures are 16°C and 4°C respectively. Rainfall is the only source of recharge of underground water. The annual replenishable Ground Water Resources recharge during the monsoon and non- monsoon months are respectively, 34098 and 6170 Ham, for the whole of Shillong City.The campus of Shillong Polytechnic, Shillong, and its surrounding areas are identified here as the study area for analysis of the water quality. The following are the detailed area of the study.

Shillong Polytechnic.

In its present campus, Shillong Polytechnic, have been using Ground water, drilled from below the ground, within the campus itself, and is the main source of supply for the main Institute building, the Boy’s hostel, Girl’s Hostel and Staff Quarters.

â??â??â??â??â??â??â??MawlaiKyntonMassar.

The MawlaiKyntonMassar locality meets its water demands through three main sources. The Umsohlang Surface stream, where water is collected from public distribution points, Ground water spring, distributed by means of private water tankers and private Ground water tube wells.

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The GSWSS, by the PHED, is one of the sources of water in this area, besides the Ground water Spring, Umsohlang Surface water, Ground water springs and The Private Ground water tube wells and dug wells.

Sampling Points

The Sample water was collected from the different sources of water from Points-of use (POU’s). The samples were selected at random and analysis was carried out in the Lab. The method of sample collection was in accordance to the scientific procedure and guidelines water sampling. The following list describes the different sampling points and its source.

Sl.No.	Sample No.	Source of Water	Location	Date of Collection	Time
1	SW1	Umsohlang Surface Water	ThumThum Road, MawlaiKyntonMassar	15th February,2017	9:20 a.m.
2	SW2	Spring Water	ThumThum Road, MawlaiKyntonMassar	15th February,2017	9:32 a.m.
3	SW3	Borewell, Underground Water	Block D, MawlaiKyntonMassar	15th February,2017	9:45 a.m.
4	SW4	Borewell, Underground Water	Shillong Polytechnic Campus, Staff Quarters	23rd February,2017	11:00 a.m.
5	SW5	Borewell, Underground Water	Girl’s Hostel, Shillong Polytechnic, Shillong	23rd February,2017	11:10 a.m.
6	SW6	Spring Water	Umshyngiar, MawlaiMawdatbaki,	24th February, 2017	10:45 a.m.
7	SW7	PHE Water, Mawphlang Source	MawlaiMawdatbaki,	01st March,2017	10:12 a.m.
8	SW8	Borewell, Underground Water	Chemistry Laboratory, Shillong Polytechnic,	01st March,2017	10:30 a.m

Table 3.1. Sampling Points.

Methodology

The quality of the water was analysed for its physical, chemical and biological characteristics in the Chemistry laboratory of Shillong Polytechnic, Shillong. Physical characteristics like Temperature, Turbidity, Colour, Taste and Odour was determined . The chemical test involves the identification of the different elements and metals i.e.pH, Electrical Conductivity, Hardness, DO, BOD, Alkalinity, iron, arsenic, fluoride, nitrate-nitrogen, present in the water and were quantified in relation to the Indian Standards of Drinking water.

The different test adopted, are as summarized below:

	Parameters	Methods
1.	pH	pH Meter
2.	Conductivity	2Conductivity Meter
3.	Turbidity	Turbidity Meter/Experimental Method
4.	Hardness	Titration method using EDTA
5.	TDS	Evaporation method
6.	Alkalinity	Titration method using H2SO4
7.	Iron	Experimental method using 1,10 Phenanathroline and Hydroxyl amine hydrochloride.
8.	Arsenic	Experimental method using Potassium Iodide
9.	Flouride	Experimental method using Alizarin
10.	Nitrate-Nitrogen	Experimental method using Brucine Solution.
11.	Lead	Experimental method using EDTA.
12.	BOD	Winkler method after Incubation.
13.	DO	Winkler Method.
14.	Chloride	Titration method using Silver Nitrate with Potasssium Chromate as indicator.

                               Table 4.1: Experimental Methods of Laboratory Testing of Different Parameters [25-28]

Results and Discussion

The different Physico-Chemical and Biological parameters of water samples collected from different sources are shown in Table 5.1

Parameters	Unit	SW1	SW2	SW3	SW4	SW5	SW6	SW7	SW8
Temperature	°C	13	13	14	18	22	18	21	21
Colour		Colourless	Colourless	Colourless	Colourless	Colourless	Colourless	Colourless	Colourless
Odour		Odourless	Odourless	Odourless	Odourless	Odourless	Odourless	Odourless	Odourless
pH	-	6.7	6.0	5.5	4.8	5.6	5.1	7.4	5.9
Turbidity	-	Slightly Turbid	Slightly Turbid	Slightly Turbid	Clear	Slightly Turbid	Slightly Turbid	Clear	Clear
Conductivity	μS	164	109	148	121	126	180	103	101
TDS	mg/dm3	0.8	0.4	0.4	0.4	0.8	0.4	0.8	0.8
Hardness	mg/dm3	BDL	BDL	BDL	BDL	BDL	BDL	BDL	BDL
Alkalinity	mg/dm3	BDL	BDL	BDL	BDL	BDL	BDL	BDL	BDL
Arsenic	mg/dm3	BDL	BDL	BDL	BDL	BDL	BDL	BDL	BDL
Nitrate	-	Nil	Nil	Nil	Nil	Nil	Nil	Nil	Nil
Lead	mg/dm3	0.009	0.005	0.006	0.004	0.005	0.008	0.005	0.007
Flouride	mg/dm3	BDL	BDL	BDL	BDL	BDL	BDL	BDL	BDL
Iron	mg/dm3	0.03	0.04	0.02	0.04	0.04	0.04	0.05	0.05
Chloride	mg/dm3	30	30	40	30	30	39	19	39
Dissolved Oxygen	mg/dm3	0.1	0.06	0.08	0.08	0.04	0.04	0.15	0.15
BOD	mg/dm3	30	20	30	10	12	13	30	20

Table 5.1: Quality Parameters of Physico-Chemical and Biological Characteristics of Drinking –Water Quality from Different Points-of-Use.

BDL – Beyond Detectable Limit

As per IS:10500 standards, the range of pH for potable water is between 6.5 – 8.5. In this study, it is observed that except for SW7, all water samples show acidic pH, below the accepted standard of IS:10500. The underground water within the campus of Shillong Polytechnic, was found to be highly acidic. The reason for this could be because of some contamination, which requires a detailed study, to identify the cause. Since, all water samples for the study were collected from within a close proximity of each other, the main source of these samples is mostly underground water, hence the similarity of the pH of the water, where a stark difference in the pH of 7.4 is observed for the sample collected with its source from the PHE water supply, indicating a possible treatment of the water to maintain a pH within the range of IS:10500 standards.

The presence of Lead, Iron, Chloride, is well within the permissible limit, which does not pose any threat to the quality of the water in terms of their contamination. The presence of arsenic cannot be ascertain with the existing experimental methods, and needs more detailed analysis and study, as it can be very harmful if present in very small quantities in the water.

Flouride content, for these samples, is relatively low, beyond the level of its detection. Alkalinity is negligible, owing to the low pH of the different samples of water. The water samples are soft, as minute quantities of hardness producing salts are present. Dissolved oxygen and the BOD are also well within the permissible limit of WHO Guidelines.

It can be mentioned that all the water samples has good aesthetics, as they are colourless, odourless and tasteless, besides being slightly turbid for some. Low TDS values were recorded and the Conductivity is indicative of the presence of some ions.

Conclusion

From the above study, it can be concluded that the sample water collected from the different sources, requires more detailed analysis and study, especially with regards to the chemical properties of water with reference to arsenic and lead, and other metals and minerals that may be present in the water, to be able to quantify its potability. As the sample collection was undertaken at low temperatures, most of the tests carried out may not show quantifiable results.

It may be mentioned here that the water requires a certain amount of treatment with respect to its physical and biological parameters.

Acknowledgement

The authors acknowledge AICTE-NQIP programme for sponsoring this work and also the headman of Mawlai Kynton Massar, Shillong for his cooperation and support.

Conflict of Interest

The authors declares no conflict.

References

19. Gleick, P. H. (1998). The human right to water. Water policy, 1(5), 487-503.
20. Elimelech M.Journal of Water Supply: Research and Technology-Aqua. 2006; 55 (1): 3–10.
21. Schwarzenbach, R. P., Egli, T., Hofstetter, T. B., Von Gunten, U., & Wehrli, B. (2010). Global water pollution and human health. Annual review of environment and resources, 35(1), 109-136.
22. RayRN. Hand book on water testing., Ph. D (I.I.Sc., Bangalore).
23. Khadse, G. K., Kalita, M. D., Pimpalkar, S. N., & Labhasetwar, P. K. (2011). Surveillance of drinking water quality for safe water supply—a case study from Shillong, India. Water resources management, 25, 3321-3342.
24. Tiwari, A., Joshi, S. K., Tripathi, S. K., & Saxena, R. (2021). Spatial pattern of groundwater recharge in Jhansi district in the Bundelkhand region, central India. Environment, Development and Sustainability, 23(12), 18618-18630.
25. Manual, A. C. T. (2009). Introduction to drinking water quality testing.
26. Gautam, S. P., Reeta, K., Suniti, P., Basu, D. D., & Kamyotra, J. S. (2011). Guide manual: Water and wastewater analysis. Central Pollution Control Board, Ministry of Environment & Forests, Government of India: New Delhi, India.
27. Water Quality Analysis Methods, Dr. (Mrs.) Leena Deshpande, National Environmental Engineering Research Institute (NEERI), Nagpur Council of Scientific & Industrial Research,New Delhi, Govt. of India.
28. Gulick W.Iodometric determination of iron, Department of Chemistry, Michigan Technological University.