More on Uranium Contamination in Groundwater
- Uranium concentrations in India’s shallow groundwater range from 0-532 parts per billion (ppb).
- Uranium concentration is found to be within safe limits in 13 states and none of the samples collected from Kerala had its presence.
- Twelve Indian states have uranium levels beyond permissible limits in their groundwater.
- State Wise: Punjab is the worst-affected state in terms of the percentage of wells found to have uranium concentration.
- Uranium presence in Punjab’s groundwater is found to be 17.7 times more than the safe limit prescribed by WHO.
- Other State: Haryana is the second state in terms of uranium prevalence in groundwater.
- Groundwater in Uttar Pradesh, Rajasthan and Delhi was found to have a toxic concentration of uranium.
- Uranium concentration was found to be higher than the threshold level in localised pockets of seven other states— Madhya Pradesh, Tamil Nadu, Chhattisgarh, Gujarat, Odisha, Telangana and Bihar.
- Silver Lining: In a 2019 assessment, groundwater in 18 states was found to be contaminated with uranium.
- This year, uranium levels in six states — Andhra Pradesh, Himachal Pradesh, Maharashtra, Goa, Karnataka and West Bengal — are currently upgraded to ‘within the prescribed limits’ zone.
Drinking Water Standards for Uranium
- WHO have set drinking water standards for Uranium concentration in drinking water at 30 μg/L.
- The Atomic Energy Regulatory Board, India has prescribed the maximum limit of Uranium in drinking water at 60 μg/L (ppb).
- Bureau of Indian Standards (BIS)Indian Standard IS 10500: 2012 for Drinking Water specification has specified the maximum acceptable limits for radioactive residues as alpha and beta emitters, values in excess of which render the water not suitable.
- Uranium is a primordial and heaviest naturally occurring radioactive element that occurs in dispersed state in the earth’s crust. It is commonly present in lignite, monazite and phosphate rocks.
- Uranium found in bedrock, and deep bedrock aquifers are much more probable to have raised uranium amounts than shallow wells.
Causes of Uranium Contamination of Groundwater
|Geogenic (naturally occurring) Processes||
Health Impact of Uranium Contamination
- Kidney ailments: Elevated levels of uranium from any source, including drinking water, can increase a person’s risk of kidney damage.
- Bone deformity: Consumption of drinking water contaminated with uranium can also cause deformity of bones and liver.
- Cancer risk: Uranium can decay into other radioactive substances, such as radium, which can cause cancer with extensive exposures over a long enough period of time.
- Remedial strategies: Methods to reduce the amount of uranium mixing with groundwater:
- Redox Technologies: These technologies attempt to reduce oxidation that triggers leaching of uranium in aquifers.
- Co-precipitated Iron Oxy-hydroxide: This technology gives only short term results and leads to temporary stabilisation and the reaction is reversed as the precipitate ages.
- Phosphate Precipitation Technologies: These technologies apply and modify phosphate with uranyl (uranium VI) forms to remove soluble uranium and prevent further dissolution of uranium.
- Flushing Technologies: This uses a variety of leaching solutions to dissolve solid-phase uranium and hydraulic extraction techniques to remove the soluble uranium.
- Other methods include:
- Adsorption or ion exchange
- Reactive sorption
- Reverse osmosis
- Inclusion of uranium monitoring in the current water quality monitoring program in India.
- More research on health risks associated with areas having high uranium contamination of water and soil.
- Treatment of groundwater contaminated with uranium for safe drinking.
Central Ground Water Board (CGWB)
- It is a subordinate office of the Ministry of Jal Shakti, Department of Water Resources, River Development and Ganga Rejuvenation.
- It has been constituted under Section 3(3) of the ‘Environment (Protection) Act, 1986’ for the purpose of regulation and control of ground water development and management in the Country.
- It is the National Apex Agency entrusted with the responsibilities of providing scientific inputs for management, exploration, monitoring, assessment, augmentation and regulation of ground water resources of the country.