Chennai groundwater quality · October 2026
Chennai water quality by area — groundwater TDS & hard water
How hard or salty the groundwater is across Chennai, neighbourhood by neighbourhood. The number is TDS(total dissolved solids) — roughly how much salt and mineral is in the water, the thing that makes borewell water hard, scaly or brackish. Figures come from 93 Central Ground Water Board wells (2000–2022).
Of 102 Chennai areas with usable groundwater readings, Guduvancheri has the freshest (230 mg/L) and Triplicane the hardest/saltiest (1,850 mg/L). As a rule the coast and the south-east run brackish, while inland and western areas are softer.
What the TDS bands mean (BIS IS 10500)
Fresh (under 500 mg/L) — Within the drinking-water limit. Soft to moderately soft.
Slightly hard (500-1,000 mg/L) — Above the ideal limit but usually fine with basic filtering. Some scaling.
Hard / brackish (1,000-2,000 mg/L) — Hard water. An RO unit is the norm here; taste and scaling are noticeable.
Very saline (over 2,000 mg/L) — Beyond the permissible ceiling. Not for drinking without treatment; borewell water often tastes salty.
Chennai areas by groundwater quality, freshest first
102 areas with a real test well close enough to be meaningful. Faded rows are medium confidence (the nearest well is further away).
1Guduvancheri230mg/LFresh · high confidence2Navalur246mg/LFresh · medium confidence3Mannivakkam366mg/LFresh · high confidence4Avadi388mg/LFresh · medium confidence5Urapakkam390mg/LFresh · high confidence6Potheri (SRM)456mg/LFresh · medium confidence7Mudichur466mg/LFresh · medium confidence8Ashok Nagar510mg/LSlightly hard · high confidence9Kattankulathur521mg/LSlightly hard · high confidence10Sithalapakkam525mg/LSlightly hard · medium confidence11Maraimalai Nagar527mg/LSlightly hard · medium confidence12Koyambedu570mg/LSlightly hard · high confidence13Virugambakkam581mg/LSlightly hard · medium confidence14Ekkattuthangal589mg/LSlightly hard · medium confidence15Alwarpet597mg/LSlightly hard · high confidence16Saidapet604mg/LSlightly hard · high confidence17Pallavaram607mg/LSlightly hard · high confidence18Kotturpuram612mg/LSlightly hard · medium confidence19West Mambalam613mg/LSlightly hard · high confidence20Washermanpet619mg/LSlightly hard · high confidence21Vadapalani631mg/LSlightly hard · high confidence22Ramapuram638mg/LSlightly hard · medium confidence23Saligramam639mg/LSlightly hard · medium confidence24Guindy666mg/LSlightly hard · medium confidence25Santoshapuram671mg/LSlightly hard · medium confidence26Nerkundram680mg/LSlightly hard · medium confidence27Tondiarpet686mg/LSlightly hard · medium confidence28Selaiyur687mg/LSlightly hard · medium confidence29Valasaravakkam690mg/LSlightly hard · medium confidence30Tambaram691mg/LSlightly hard · high confidence31Keelkattalai693mg/LSlightly hard · high confidence32Old Pallavaram694mg/LSlightly hard · high confidence33Adyar696mg/LSlightly hard · high confidence34Perungalathur696mg/LSlightly hard · high confidence35Anna Nagar697mg/LSlightly hard · high confidence36Chitlapakkam708mg/LSlightly hard · high confidence37Mylapore718mg/LSlightly hard · high confidence38Maduravoyal732mg/LSlightly hard · medium confidence39George Town753mg/LSlightly hard · high confidence40Chromepet754mg/LSlightly hard · high confidence41Kodambakkam754mg/LSlightly hard · high confidence42T. Nagar762mg/LSlightly hard · medium confidence43Vandalur767mg/LSlightly hard · high confidence44Sowcarpet769mg/LSlightly hard · high confidence45Hasthinapuram771mg/LSlightly hard · high confidence46Irumbuliyur771mg/LSlightly hard · high confidence47Pozhichalur777mg/LSlightly hard · medium confidence48Nanganallur792mg/LSlightly hard · medium confidence49Thiruvanmiyur798mg/LSlightly hard · medium confidence50Madhavaram798mg/LSlightly hard · medium confidence51Taramani800mg/LSlightly hard · medium confidence52Madipakkam843mg/LSlightly hard · medium confidence53Ullagaram858mg/LSlightly hard · medium confidence54Manapakkam860mg/LSlightly hard · medium confidence55Nanmangalam866mg/LSlightly hard · medium confidence56Porur885mg/LSlightly hard · medium confidence57Mogappair888mg/LSlightly hard · medium confidence58Kodungaiyur896mg/LSlightly hard · medium confidence59Velachery930mg/LSlightly hard · medium confidence60Kottivakkam936mg/LSlightly hard · medium confidence61Padi937mg/LSlightly hard · medium confidence62Anakaputhur938mg/LSlightly hard · high confidence63Perumbakkam939mg/LSlightly hard · medium confidence64Panaiyur943mg/LSlightly hard · medium confidence65Adambakkam952mg/LSlightly hard · medium confidence66Moulivakkam959mg/LSlightly hard · medium confidence67Kundrathur959mg/LSlightly hard · medium confidence68Purasawalkam960mg/LSlightly hard · high confidence69Otteri973mg/LSlightly hard · high confidence70Palavakkam976mg/LSlightly hard · medium confidence71Nungambakkam981mg/LSlightly hard · medium confidence72Alandur982mg/LSlightly hard · high confidence73Poonamallee992mg/LSlightly hard · medium confidence74Vanagaram994mg/LSlightly hard · medium confidence75Kolathur997mg/LSlightly hard · medium confidence76Aminjikarai1,023mg/LHard / brackish · high confidence77Iyyappanthangal1,031mg/LHard / brackish · medium confidence78Besant Nagar1,037mg/LHard / brackish · high confidence79Pazhavanthangal1,039mg/LHard / brackish · high confidence80Medavakkam1,041mg/LHard / brackish · high confidence81Vyasarpadi1,044mg/LHard / brackish · high confidence82Perungudi1,047mg/LHard / brackish · high confidence83Villivakkam1,048mg/LHard / brackish · medium confidence84Chetpet1,048mg/LHard / brackish · medium confidence85Padur1,049mg/LHard / brackish · medium confidence86Egmore1,058mg/LHard / brackish · medium confidence87Ayapakkam1,075mg/LHard / brackish · medium confidence88Ayanavaram1,080mg/LHard / brackish · high confidence89Perambur1,083mg/LHard / brackish · high confidence90Kilpauk1,102mg/LHard / brackish · high confidence91Injambakkam1,118mg/LHard / brackish · high confidence92Royapettah1,164mg/LHard / brackish · high confidence93Tirumullaivoyal1,230mg/LHard / brackish · medium confidence94Korattur1,242mg/LHard / brackish · medium confidence95Neelankarai1,272mg/LHard / brackish · medium confidence96Thoraipakkam1,276mg/LHard / brackish · medium confidence97Karapakkam1,420mg/LHard / brackish · medium confidence98Pallikaranai1,589mg/LHard / brackish · high confidence99Kallikuppam1,634mg/LHard / brackish · medium confidence100Ambattur1,691mg/LHard / brackish · high confidence101Sholinganallur1,833mg/LHard / brackish · high confidence102Triplicane1,850mg/LHard / brackish · high confidence
Read this before you rely on it
- This is groundwater (borewell/open-well), not your piped Metrowater tap supply— a flat on Metrowater may be fine even where the groundwater is hard.
- Groundwater TDS swings with the seasons: a dry-summer reading can be far saltier than the same well after the monsoon.
- There are only 93 wells across the metro, so each area’s figure is interpolatedfrom the nearest ones — treat it as orientation, not a lab test of a specific building. Confidence shows how close the nearest real well is.
Cite this
Free to reference with credit and a link back. Suggested citation:
Source: Chennai groundwater quality by area, vaadagai.homes, from Central Ground Water Board (CGWB) wells (2000-2022). https://vaadagai.homes/chennai-water-quality
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