Status of groundwater quality in Bangalore: Conducted by the Department of Mines and Geology, Government of Karnataka

The study collected 918 samples from 735 locations across an area of 400 square kilometers of the city and its environs. The samples were collected in March and April of 2003. Testing was done for 25 parameters. The results indicate that -

• In 370 locations (50.34%), the groundwater was found not suitable for domestic purposes as per the the ISO 10500:1991 standard.
• 278 samples showed higher than permissible nitrate contamination, as high as 747 mg/L in some samples (permissible limit of 50 mg/L).
• Bacteriological contamination was tested separately at 100 locations that were deemed high-risk, and contamination was found in 74 of the 100 samples.
• The fact that as far back as 2003, groundwater quality was already this bad underlines the urgency of the water quality problems in all urban areas.