Abstract

Water is essential for life as all living beings rely on it for survival and day-to-day activities. Water is essential for every trekker, so everyone carries a water bottle to quench their thirst when they get tired after walking for hours. Based on the level of activity, intensity level, duration, weather, age, sweat rate and body type, the amount of water an average trekker requires is about half-liter of water per hour of moderate activity in moderate temperatures. In case of high intensity level, trekkers may require one liter of water per hour or more. Considering the importance of water quality in trekking regions, the study focuses on the assessment of physio-chemical and microbiological parameter of waters in Rolwaling valley trek. The results revealed that the water quality of tap water and stream in the Rolwaling valley meet the standards. However, parameter for Iron exceeded their NDWQS and WHO standard to some extent. The pH values were also altered due to presence of organic and inorganic solutes together with reaction of carbon dioxide. Most of the physio-chemical parameters in this study have met the NDWQS and WHO standards. Thus, it leads me to believe that the water quality of the Rolwaling valley to be ‘excellent’ and fit for human consumption and usage. This pioneer attempt on the water quality assessment of the Rolwaling valley trek located in the highly inaccessible area of the Gaurishankar Himalayan range can be a good reference for further study on the numerous trekking trails in Nepal.
Keywords: Water, Quality Assessment, Trekking, Mountaineering, Physio-Chemical Parameters

Introduction

Water is essential for life as all living beings rely on it for survival and day-to-day activities. Glacier-fed lakes, rivers and tributaries are the major sources of drinking water for trekkers, pilgrims, and wildlife within the Himalayas (R. Kumar & R.C., Sharma, 2019). As per the United Nations conference on Sustainable Development, the mountain ecosystem plays a key role in fulfilling the water requirement to a large population of the world (UNCSD, 2012¹). The rivers in the Himalayas are either rain-fed, spring-fed, ground water-fed or glacier-fed/snow-fed. Some rivers originate from various lakes within the Himalayas, in the case of Rolwaling valley, Tsho Rolpa river originates from the largest glacial lake in Nepal, Tsho Rolpa. All the lakes located above an altitude of 3,500m above, in the Himalayas are considered to be glacier-fed (WWF, 2005²).

The rivers originating from the Himalayas are the lifeline of 20% of the world’s total population as the water from these rivers has been utilized for activities such as hydropower, irrigation, domestic and industrial uses. Precipitation and aerosol chemistry play core roles in governing the water quality in the Himalayan region as they carry and deposit significant number of pollutants in far distant areas capable of altering water quality (Sharma et al., 2019³). Increase in the pollution level of lakes and rivers is the key issue at hand for drinking purposes (Kazi et al., 2009⁴). The water quality assessment methods have been used to evaluate the quality of water and make decisions for its use based on the results (Rawat. R. et al., 2020⁵). Organizations such as WHO, BIS, CPCB, ICMR, NDWQS, have recommended standards for various physio-chemical and microbial characteristics to compare and decide on the use.

Water Quality Index

WQI can be defined as a rating which reflects the composite influence of various water quality parameters. WQI was first conceptualized in 1965. WQI is an aggregate value accepted as a rating that resembles the overall quality of the water. It is one of the effective tools to access the quality of a water body (Rana et al., 2018⁶) and communicates the acquired information to citizens and policy makers for proper conservation and management of the water body.

Water Quality Parameters

Water pollution can be assessed on the basis of certain parameters:

a. Physical Parameters: Temperature, Turbidity, Color, Conductivity, dissolve and total solids.

b. Chemical Parameters: Acidity, Alkalinity, Salinity.

c. Microbiological: Coliform, E.Coli, and other pathogenic organisms.

Physio-Chemical Parameters

These parameters are used to detect the presence of inorganic matter, soluble salts, of organic matter in water. The chemical standards for drinking water are of secondary concern in a source subject to bacterial contamination. Thus problems associated with chemical characteristics of drinking water that arise due to adverse health effects after long periods of exposure. The contaminants that have toxic properties, such as heavy metals and constituents are of primary concern.

pH

pH is the measures of intensity of acidity or alkalinity. The standard pH value of drinking water from any sources is 6.5-8.5, according to both NDWQS and WHO. If the pH value is lower than 7.0, corrosion in the distribution system occurs and with pH value higher than 8.0 makes disinfection with chlorine less effective.

Total Hardness

Hardness is the property of water that prevents the formation of lather with soap and increases the boiling point of water. Calcium and Magnesium are the core minerals that contribute to total hardness. It is usually expressed as the equivalent quality of calcium carbonate.

Alkalinity

The existence of all hydroxyl ions capable of interacting with the hydrogen ion characterizes water’s alkalinity, which is a measure of its ability to neutralize strong acids. Alkalinity is primarily caused by bicarbonate and carbonate. The pH, calcium, and alkalinity relationship determines if water is caustic or if calcium carbonate will be deposited.

Turbidity

The amount of particles floating in water that reduces the passage of light through the water is measured as turbidity. Soil particles (clay, silt, and sand), algae, plankton, bacteria, and other things are among the suspended components. These materials usually range in size from 0.004 mm (clay) to 1.0 mm (sand).

Carbonate & Bicarbonate

Inorganic anions are carbonate and bicarbonate. The carbonate ion has a -2 electrical charge, while the bicarbonate ion has a -1 electrical charge. Furthermore, because of the hydrogen atom’s presence. Another notable distinction between carbonate and bicarbonate is that carbonate ions will be more abundant in strongly basic environments, but bicarbonate ions will be more abundant in weakly basic solutions. Also, the capacity to dissolve in water plays a role in the distinction between carbonate and bicarbonate. At room temperature and atmospheric pressure, carbonate ion complexes are not soluble in water. Many bicarbonate salts, on the other hand, are soluble in water at room temperature.

Manganese

Manganese is one of the most common metals in the Earth’s crust, and it is found in combination with iron. It’s found in over 100 minerals, but it’s not found in its pure (elemental) form in nature. Manganese is required for the normal functioning of several cellular enzymes (e.g. manganese superoxide dismutase, pyruvate carboxylase) and can help to activate others (e.g. kinases, decarboxylases, transferases, hydrolases) (IPCS, 2002⁷). Manganese can exist in 11 different oxidative states, with Mn2+, Mn4+, and Mn7+ being the most ecologically and physiologically relevant.

Calcium

In both saltwater and freshwater, calcium, in the form of the Ca2+ ion, is one of the most abundant inorganic ca= ions, or positive ions. It can be caused by the dissociation of salts in water, such as calcium chloride or calcium sulfate. Streams flowing over limestone, CaCO3, gypsum, CaSO4•2H2O, and other calcium-containing rocks and minerals provide the majority of calcium in surface water. Even more calcium ions are leached from rocks and soil by groundwater and underground aquifers. Calcium carbonate is highly insoluble in water, but dissolves more quickly in water with dissolved carbon dioxide.

Iron

Because of the poor taste in the water, the discoloration of washed garments, and the possible deposition of the elements in the distribution system, iron is unpopular. Although they have no physiological importance, iron encourages the growth of unwanted bacteria (“Iron bacteria”) in the water and distribution system, resulting in the formation of a slimy coating on the pipes. The recommended iron levels are 0.3 mg/l. When oxidized, the ferrous salt of iron in drinking water supplies precipitates as ferric hydroxide, while ground water contain iron (II) in various concentrations without turbidity, but turbidity and color develop in piped systems at iron levels above 0.05 – 1 mg/l when pumped directly from a well.

Arsenic

Arsenic is a metalloid found in rocks, soil, natural water, and living creatures. It enters the water supply mostly through the dissolving of naturally occurring minerals and ores. Pesticides, chemical fertilizers, and industrial discharges are all anthropogenic sources of arsenic. The Terai regions of Nepal have been discovered to have high levels of arsenic. Digging out tube-wells is the simplest and most instantly accessible source of water in Nepal’s rural areas. The problem of arsenic is complicated, and the answer is difficult. Within small areas, the subterranean distribution of arsenic is highly varied. Arsenic is mostly found in shallow aquifers, those less than 150 meters deep. Deep aquifers, on the other hand, are occasionally discovered to be invisible and have no effect on taste and smell.

Microbiological Parameters

Microbiological testing of drinking water is primarily used to detect recent and potentially harmful faecal pollution. Contamination of drinking water by human and animal excrement, as well as sewage, is hazardous if there are carriers of infectious enteric diseases that be spread through the water among the contributing population. Viruses, bacteria, protozoa, helminthes, and other disease-causing organisms can be classified as virus, bacterium, protozoa, or helminthes. Coliform organisms have long been acknowledged as a good microbiological indicator of drinking water quality, owing to their ease of detection and quantification in water.

 Coliform organisms are Gram-negative, rod-shaped bacteria that can ferment lactose at 35-37°C and produce acid, gas, and aldehyde within 24-48 hours. They can also thrive in the presence of bile salts or other surface-active substances with similar growth limiting qualities. They’re also oxidase-negative, don’t generate spores, and have galactosidase activity. Escherichia coli, Citrobacter, Enterobacter, and Klebsiella are examples of coliform bacteria. Warm-blooded animals, including humans, have E.Coli in their intestines. As a result, the presence of E.Coli in water samples shows the presence of fecal matter, which imply the presence of human pathogenic organisms.

Study area

Figure 1 Sites Selected for Water Quality Assessment in Rolwaling Valley (Source: Objective Hazard Assessment: An Observation from Rolwaling Valley)

The valley of Rolwaling is located in the Dolakha District of Bagmati Province of Nepal. It extends from the Tamakoshi river in the west to Nangpa La (Pass), where the Mahalangur section of the Himalaya starts, as seen in figure 1. The Sherpa villages of Simi, Beding and Na are located within the valley. Mt. Gaurishankar is the highest mountain in the region followed by Chekigo, Yalung-Ri, Bamugo, and more. The valley of Rolwaling is also home to the Gaurishankar Conservation Area Project (GCAP), which acts as the overseer of the anthropogenic activities that can be conducted there.

Rolwaling valley is one of the most remote places in Nepal and a popular destination for trekkers, pilgrims and researchers. The trek into the valley starts from the village of Simi in the south-west and then the trail follows the Tsho Rolpa/Rolwaling river east towards the Tsho Rolpa glacial lake. Hundreds of Trekkers visit the glacial lake every year, and all of them rely on the resources available within this region to sustain themselves during their trek. Water is essential for every trekker, so everyone carries a water bottle to quench their thirst when they get tired after walking for hours. Based on the activity, intensity level, duration, weather, age, sweat rate and body type, the amount of water an average trekker requires is about half-liter of water per hour of moderate activity in moderate temperatures. In case of high intensity level, trekkers may require one liter of water per hour or more.

The streams along the trekking trail in Rolwaling valley also originate from high altitude glaciers. The water along the routes can be treated with chlorine and iodine disinfectants to purify it of any bacteria or viruses. But the most effective would be boiling the water and then drinking it. The chemical parameter of drinking water is significant in relation to public health. Notably, iron, ammonia, nitrates and arsenic have adverse health impacts (Aryal, J. et al., 2010⁸).

National Drinking Water Quality Standards 2062 & WHO Standards

Methodology

The selection of the sampling sites and the samples to be considered in this study was solely selected based on the itinerary of the Rolwaling Valley trek. This consisted of collecting water samples in major locations that trekkers are likely to rest up and hydrate before starting their trek. For example: A normal trek itinerary requires a trekker to stay a night at Simi Gaun on their arrival. So they are most likely to drink water available in the hotels. Locations that are attributed to lunch breaks and snacks were also considered viable site for water sample collection.

Water samples for field and laboratory testing were collected in separate bottles, as prescribed by APHA 2017. Water samples from the sampling sites were collected in two bottles and a sterilized poly-reagent plastic bottle. 

1. 625 ml, collection bottle for laboratory analysis of physio-chemical parameters such as pH, temperature, EC, alkalinity, Total hardness, Bicarbonate & Carbonate.

2. 100ml, poly-reagent sterilized plastic bottle for metal testing of presence of Arsenic.

3. 10ml PA vial was used to identify the presence of E. Coliform in the water samples. 

A total of 3 samples from each site were taken to determine the concentration of water quality parameter considered for this study. The methods applied by ENPHO Lab are standards placed by APHA(American Public Health Assoiciation), AWWA(American Water Works Association) and WEF(Water Environment Federation).

Results and Discussion

Simi Gaun

All the values of the Physio Chemical parameters for tested samples from Simi village were found to be within the NDWQS-2062. Table 3 shows the result of physio-chemical parameters for drinking water quality of tap water in Simi Gaun. The test kit used to detect the presence of E.Coli came back negative as well. The result seemed obvious because the drinking water system in place at Simi village made use of pipes to supply water. And since a water tank is used a reservoir of sort, contamination of fecal matter seems far fetched

Surmuche

The water samples from Surmuche also showcased similar values of the Physio-chemical parameters. A decreased level of concentration in parameters such as Bicarbonate, Alkalinity, Hardness, and Calcium is present in the water samples.  The pH level of both water samples stands at 6.88. Major differences could not be identified between water samples collected at Simi village and Surmuche. The test for E.Coli also came back negative.

Dongang

Most of the physio-chemical factors stay the same. In Table 5, we can see a slight increase in the concentration of iron in the water i.e. 0.41. The NDWQS and WHO standard for iron is 0.3, so the water doesn’t meet the standards out forth. This result also be attributed to the corrosion of the metal pipe used for supply of water to the two hotels available in Dongang. Water constituting of pH value less than 7.0 can cause corrosion in drinking water supply system. The test E.Coli came back negative for the water sample collected in Dongang.

 Beding

An increase in the concentration of the physio-chemical factors can be noticed with an increase in altitude. Further research is needed to explain the reason for these attributes. The results of Beding village match the results of Dongang. With its iron content higher than the water sample collected at Dongang. The concentration level in Beding is 3 times higher than the recommended standard. As such trekkers in the region must refrain from drinking untreated water from streams near Beding village. The other parameters meet the standards put forward by Nepal government and WHO. A negative response was also noted for the presence of E.Coli in the water of Beding village.

Na Gaun

All the physio-chemical parameters for the water samples collected at NA village met the standards provided by Nepal government and WHO. This result showed a contrast in the iron composite of the water available in higher mountain region of Nepal. The use of a drinking water system in NA can be cited as the primary reason for such substantial change in Iron concentration in the water samples collected at Beding and NA. NA and Simi village share the same type of drinking water supply system.

Conclusion

Most trekkers don’t have much choice when it comes to making choices on drinking water. A normal trekker would fill their bottles with water they can find along the route, through the means of taps or streams. The latter poses greater risk to the health condition of the trekker. Especially when gaining altitude, the risk increases exponentially.

As such trekkers need to be on the top of their game. Samples collected at Simi Gaun, Surmuche, and Na Gaun have met the NDWQS and WHO standards. In the case of Dongang and Beding, concentration of Iron was found to be above the recommended standard; ie 0.41 & 0.93 in Table 6 & 5 respectively. Iron is commonly found in the environment and diet and in small amount it is required for mainting good health but in larger amount, they can be toxic or dangerous (Shah, A., 2017⁹). Heavy metal toxicity can lead to lower energy levels and functioning of the vital organs of the  trekkers visiting the Rolwaling valley. However, Iron found in the water or air is found in the ferrous form. This form of iron is found abundantly in the environment and is stable in water free of carbon dioxide (Kamble, R.K., et al, 2013¹⁰). 

Surface water may contain ferric iron in a metastable suspension and iron in such waters can be removed by centrifuging or filtration to a point where the remainder is below detection (T.B., Nolan. 1962). Thus, trekkers visiting the Rolwaling valley must employ water treatment techniques  such as, Sedimentation, Filtration, Disinfection, and fluoridation. These techniques were not employed in the field and require investigation.

References

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Nimesh Jung Gauli is a Freelancewriter for Himalayan Gazette.

Nimesh Jung Gauli

A traveller 🌍🚶‍♂️📸 and writer✍️ by passion. A freelance trekking guide in Nepal that graduated from Nepal Mountain Academy and has successfully climbed a 6100m peak.