Contamination of Arsenic
in Groundwater of Bara District, Nepal
Sadhana Pradhanang Kayastha and Kailash Pradhanang
Abstract Groundwater is the major source of water for drinking and household
purposes in Nepal’s Tarai districts. This study was conducted to evaluate the concentration of arsenic (As) in deep and shallow groundwater and its association with iron,
manganese, depth and age of the tube wells/dug wells in Bara District. Groundwater
samples (36) were collected from randomly chosen wells (dug wells and tube wells)
of Bara District, in 2017. As concentrations of water were measured by hydride
generation atomic absorption spectrometry (AAS). About 50% of tube wells/dug
wells exceeded permissible value 10 ppb of WHO drinking water guideline, but
16% tube wells/dug wells exceeded permissible values of Nepal Interim Standard of
arsenic (50 ppb). As concentrations were highly correlated with iron and manganese.
The higher concentrations of As in some of the sites of the study area were attributed
to the groundwater geochemistry in the study area. As contamination was found high
at the depth range of tube wells <20 m, which was constructed in last 10–15 years.
The risk of As contamination to the people living in and around study area is high
because the contaminated water has been used daily for household purposes such as
cooking, drinking and other purposes.
Keywords Groundwater · Tarai · Arsenic · Bara District · Permissible
1 Introduction
Nepal is famous for its surface and groundwater resources. Due to rapid growth
of urban population, the demand for water is always increasing. Groundwater has
always been the major source of water for drinking in Tarai District [14]. About
90% of people are using groundwater for drinking purpose since ancient period,
S. P. Kayastha (B)
Central Department of Environmental Science, Tribhuvan University, Kirtipur, Kathmandu, Nepal
e-mail: sadhana.pradhanang@gmail.com
K. Pradhanang
Ratna Rajya Laxmi Campus, Tribhuvan University, Kirtipur, Kathmandu, Nepal
© Springer Nature Singapore Pte Ltd. 2021
C. Bhuiyan et al. (eds.), Water Security and Sustainability,
Lecture Notes in Civil Engineering 115,
https://doi.org/10.1007/978-981-15-9805-0_3
17
in Groundwater of Bara District, Nepal
Sadhana Pradhanang Kayastha and Kailash Pradhanang
Abstract Groundwater is the major source of water for drinking and household
purposes in Nepal’s Tarai districts. This study was conducted to evaluate the concentration of arsenic (As) in deep and shallow groundwater and its association with iron,
manganese, depth and age of the tube wells/dug wells in Bara District. Groundwater
samples (36) were collected from randomly chosen wells (dug wells and tube wells)
of Bara District, in 2017. As concentrations of water were measured by hydride
generation atomic absorption spectrometry (AAS). About 50% of tube wells/dug
wells exceeded permissible value 10 ppb of WHO drinking water guideline, but
16% tube wells/dug wells exceeded permissible values of Nepal Interim Standard of
arsenic (50 ppb). As concentrations were highly correlated with iron and manganese.
The higher concentrations of As in some of the sites of the study area were attributed
to the groundwater geochemistry in the study area. As contamination was found high
at the depth range of tube wells <20 m, which was constructed in last 10–15 years.
The risk of As contamination to the people living in and around study area is high
because the contaminated water has been used daily for household purposes such as
cooking, drinking and other purposes.
Keywords Groundwater · Tarai · Arsenic · Bara District · Permissible
1 Introduction
Nepal is famous for its surface and groundwater resources. Due to rapid growth
of urban population, the demand for water is always increasing. Groundwater has
always been the major source of water for drinking in Tarai District [14]. About
90% of people are using groundwater for drinking purpose since ancient period,
S. P. Kayastha (B)
Central Department of Environmental Science, Tribhuvan University, Kirtipur, Kathmandu, Nepal
e-mail: sadhana.pradhanang@gmail.com
K. Pradhanang
Ratna Rajya Laxmi Campus, Tribhuvan University, Kirtipur, Kathmandu, Nepal
© Springer Nature Singapore Pte Ltd. 2021
C. Bhuiyan et al. (eds.), Water Security and Sustainability,
Lecture Notes in Civil Engineering 115,
https://doi.org/10.1007/978-981-15-9805-0_3
17