Delhi ranked third among all states and Union territories with most contaminated sites, according to data released by the Central Pollution Control Board. Odisha topped the list with 23 contaminated sites, followed by Uttar Pradesh (21) and Delhi (11), according to the data.

The pollution board said there were a total of 112 sites across the country, which have been confirmed as “contaminated”. As many as 168 may be polluted but require investigation and confirmation.

The CPCB defines contaminated sites as delineated areas in which the constituents and characteristics of the toxic and hazardous substances exist at levels and in conditions which pose existing or imminent threats to human health and/or the environment”.

Apart from the landfill sites in Bhalswa and Ghazipur, industrial areas at Jhilmil, Wazirpur, New Friends Colony, Dilshad Garden and Lawrence Road are among the 11 contaminated sites in Delhi, according to PTI.

Additionally, there are 12 sites in the national Capital that were marked as “probably contaminated”.

The data also showed that remediation work had started to clean up 14 sites across seven states as per directions from the National Green Tribunal. Remediation of contaminated sites involves cleaning of contaminated media – soil, groundwater, surface water and sediments – by adopting various in-situ or ex-situ clean-up technologies up to a predefined remediation target levels for each identified constituent.