Tinsukia: A recent scientific study conducted across parts of Dibrugarh and Tinsukia districts has flagged measured concern over groundwater and surface water quality, indicating that while most sources remain fit for drinking, certain pockets show signs of deterioration linked to human and industrial activity.
Published on July 5, 2025, in the International Journal for Multidisciplinary Research, the paper titled “Assessment of Water Quality Index of Dibrugarh and Tinsukia Districts, Assam” was authored by Neelakshi Hazarika, Assistant Professor of Chemistry at Digboi College. The study analysed groundwater and surface water samples from 13 locations situated between the Noa-Dihing and Burhi-Dihing rivers during 2022.
Using the Weighted Arithmetic Water Quality Index (WQI) method in accordance with guidelines prescribed by the Bureau of Indian Standards (BIS), the research computed a composite index value to assess overall suitability for drinking purposes.
The WQI values ranged from 12.40 — categorised as “excellent” to 116.79, classified as “unsuitable for drinking.” Most of the sampled sites fell within the “good” category (WQI 25–50). Jagun recorded an “excellent” score of 12.40, while Margherita (28.18), Rongagora (36.65), Kothalguri (41.72), Udaipur (49.27) and Borjan Digboi (50.05) were rated “good.” Nabajoti (51.83) fell into the “poor” category, while Amguri, with a WQI of 116.79, was deemed unsuitable for drinking without treatment.
The study examined key physicochemical parameters, including pH, electrical conductivity, total dissolved solids (TDS), total hardness, chlorides, nitrates, sulphates, fluoride, calcium, magnesium, iron, sodium, potassium, biological oxygen demand (BOD) and dissolved oxygen (DO). Most parameters were found to be within BIS permissible limits. The pH values ranged from neutral to slightly alkaline (6.46–8.07), TDS levels were low (98.69–452.12 mg/L), and hardness levels indicated predominantly soft water.
However, certain areas showed elevated electrical conductivity, suggesting possible ionic contamination. BOD levels reached up to 29.1 mg/L at some locations, indicating the presence of organic pollution. High residual sodium carbonate (RSC) values in select samples also rendered the water unsuitable for irrigation.
“Higher Water Quality Index value suggests the presence of higher concentration of various ions in water which is an indication of pollution resulting from nearby human habitations and industrial activities,” Hazarika observed in the paper.
While all samples were considered capable of sustaining aquatic life and low mineral content made most suitable for domestic use, the study cautioned that continued acidic or polluted trends could adversely affect crops and aquatic ecosystems. The researcher recommended treatment of high-WQI sources before domestic consumption and emphasised the need for seasonal monitoring to ensure long-term safety.
In a region increasingly shaped by industrial expansion and demographic pressures across Assam’s tea and oil belts, the findings underscore the importance of vigilant local water management and sustained scientific monitoring to safeguard public health.