The official ledger — 979 quality‑affected habitations
Iron947
Fluoride18
Salinity9
Nitrate5
Hotspots: Koraput 334 · Malkangiri 212 · Kandhamal 132 · Rayagada 57 — largely tribal, JJM‑2.0 priority districts. CGWB additionally records localised fluoride >1.5 mg/L in 26 districts and shallow‑aquifer arsenic in 5 coastal districts.
Source: Govt. of Odisha affidavit to NGT (OA 728/2023), IMIS Format C17‑A, June 2024.
The ground reality runs deeper
- Nuapada: district records count 903 fluoride‑affected habitations and ~1,752 unusable tube wells — served today by a mix of mega‑PWS and ~1,100 small defluoridation units.
- Mayurbhanj (Nov 2025 field study): 2.4–8.2 mg/L fluoride in Bangriposi block — including 8.2 mg/L at a primary school — in habitations officially recorded as covered.
- Iron: state data reports ~1,972 villages with high‑iron groundwater beyond the IMIS list.
Why units fail — the O&M diagnosis
No defluoridation technology consistently worked under real field conditions… improper regeneration, absence of trained operators, and no post‑installation support.
CSIR‑NEERI field study of handpump defluoridation units, Nuapada district — peer‑reviewed, September 2025
The state's own O&M Policy 2026 reaches the same conclusion — the gap is not intent or budget, but a delivery model where treatment survives beyond installation.
Why Odisha's chemistry favours ion exchange
- Western‑belt groundwater is near‑neutral (block means pH 6.9–7.6) — squarely inside HIX‑Nano's optimal window.
- Average TDS is just ~319 mg/L — precisely where RO wastes the most water for the least benefit (50–60% reject), a concern the NGT has flagged nationally for low‑TDS sources.
- HIX‑Nano treats iron, fluoride and arsenic — matching all three of Odisha's contaminant profiles.
Chemistry: peer‑reviewed statewide phreatic aquifer study (Geoscience Frontiers, 2021) and Nuapada block‑level survey (Applied Water Science, 2023).