Pincode-wise TDS, hardness & safety

Check water quality of your area

Government groundwater data for your area — TDS, hardness and key contaminants, and whether an RO purifier is recommended.

Coverage

2,846 pincodes

CGWB groundwater monitoring, EC-derived TDS, district exceedance tables and state surveys — distilled per pincode.

Most Indian cities mapped here record average groundwater TDS above the BIS acceptable limit of 500 mg/L. Surat is the highest at about 1801 mg/L and Mangalore the lowest at about 70 mg/L. Figures are Central Ground Water Board readings for the surrounding area, not a measurement of your tap.

India Water Quality Index

Average groundwater TDS across the cities we map, from government monitoring data (CGWB / India-WRIS), set against the BIS acceptable limit of 500 mg/L. Tap a column header to sort.

Rating
Surat1801Severe
Ahmedabad1731Severe
Vizag1448Severe
Aurangabad1235Severe
Hyderabad1207Severe
Agra1200Severe
Rajkot1100High
Gurgaon1080High
Jaipur1014High
Guntur1000High
Delhi994High
Coimbatore960High
Faridabad950High
Madurai900High
Kolkata896High
Vijayawada879High
Nashik800High
Vadodara800High
Chennai780High
Mumbai719High
Indore700High
Ghaziabad696High
Kanpur650High
Noida640High
Nagpur622High
Mysore610High
Pune592High
Raipur560High
Chandigarh541High
Bangalore520High
Ludhiana503High
Patna500High
Bhopal500High
Varanasi499Acceptable
Lucknow371Acceptable
Ranchi230Ideal
Thiruvananthapuram225Ideal
Goa210Ideal
Kochi201Ideal
Bhubaneswar200Ideal
Guwahati190Ideal
Dehradun140Excellent
Thrissur120Excellent
Mangalore70Excellent

How this works

We map your pincode to the nearest government groundwater monitoring data (CGWB / India-WRIS) and compare it against BIS drinking-water limits — 500 mg/L for TDS, 200 mg/L for hardness, 1 mg/L for fluoride, 0.01 mg/L for arsenic and 45 mg/L for nitrate. It is an indicative area reading: always test your own supply.

Data sources

  • CGWB National Groundwater Quality 2018-2021 (EC-derived TDS)
  • CGWB Annual Ground Water Quality Report 2024 (2023 monitoring)
  • CGWB district groundwater brochures & state reports (2013-2024)
  • BIS IS 10500 — Indian Standard for drinking water, for all comparison limits.

Common questions

What is a safe TDS level for drinking water in India?

BIS (IS 10500) sets 500 mg/L as the acceptable limit for total dissolved solids in drinking water, and 2,000 mg/L as the permissible limit where no alternate source exists. Water below 500 mg/L is considered acceptable on TDS grounds; between 500 and 2,000 mg/L it is usually treated before drinking. TDS alone does not indicate microbial safety — it measures dissolved minerals and salts, not bacteria.

How do I check the water quality of my area by pincode?

Enter your 6-digit pincode in the search on this page. It maps your area to the nearest Central Ground Water Board (CGWB) monitoring data and shows the average TDS, how it compares with the BIS limit of 500 mg/L, the contaminants flagged for that district, and whether an RO purifier is the right fit.

Which Indian cities have the highest TDS in groundwater?

On CGWB groundwater monitoring, Surat (~1,801 mg/L), Ahmedabad (~1,731 mg/L) and Visakhapatnam (~1,448 mg/L) record the highest average TDS among the cities mapped here — roughly three times the BIS acceptable limit of 500 mg/L. Mangalore (~70 mg/L), Thrissur (~120 mg/L) and Dehradun (~140 mg/L) record the lowest.

Do I need an RO purifier for my water?

RO is warranted when TDS is consistently above 500 mg/L, or where hardness, fluoride, arsenic or nitrate exceed BIS limits. Below about 200 mg/L, RO is generally unnecessary and a UV or UF purifier preserves natural minerals while handling microbial risk. Between 200 and 500 mg/L the decision depends on hardness and specific contaminants rather than TDS alone.

Is this the same as testing my own tap water?

No. These are indicative area readings from government groundwater monitoring near your location, not a measurement of your tap. Municipal supply, borewell depth, storage tanks and plumbing all shift the number at your tap. Treat this page as a starting point and confirm with a lab test or a TDS meter on your own supply.

Where does this water quality data come from?

All figures come from Government of India sources: the Central Ground Water Board (CGWB) national groundwater quality monitoring, India-WRIS (National Water Informatics Centre), CGWB district groundwater brochures and state reports, with limits from BIS IS 10500. TDS values are largely EC-derived from monitoring conducted between 2018 and 2024.

Disclaimer: Figures are indicative area estimates from government groundwater monitoring nearest to this location and may differ from your exact tap or municipal supply. They are not a substitute for a lab test of your own water. This page is general information, not medical advice, and any product suggestion is general guidance based on typical area readings, not a diagnosis of your supply. For health concerns, consult a qualified professional.