Current status of some chemical indicators in domestic water in households in Tan Ky commune, Thai Nguyen province

Abstract

Domestic water is essential for public health, particularly in mountainous areas with limited centralised supply. Tan Ky commune, Thai Nguyen province (formerly Cao Ky commune, Bac Kan province), faces topographical challenges where reliance on selfextracted water poses chemical contamination risks. Objectives: To evaluate chemical parameters of household water in 2025 as a basis for proposing public health interventions. Methods: A cross-sectional descriptive study was conducted on 100 water samples from 64 households. Sampling: Standard techniques were applied to storage tanks, boreholes, and stream water. Atomic absorption spectroscopy (AAS) was utilised determine Fe and Mn concentrations while titration methods were adopted to measure hardness and permanganate index according to Vietnamese National Technical Regulations (QCVN). Descriptive statistics were used to assess non-compliance rates. Results: While 100% of samples met Fe standards and 96% were classified as soft water, 8% exceeded the Mn threshold (max 102 µg/l) and 15% surpassed the regulatory limit for the permanganate index (max 6.24 mgO₂/l). The highest non-compliance occurred in borehole water (17.14% for Mn; 20% for permanganate index) and stream water (21.43% for permanganate index). Conclusions: Water quality in the area exhibits localised risks of manganese contamination and localised elevated permanganate index. Enhanced periodic monitoring and household-level treatment solutions are essential to ensure community safety.