The NGT issued a notice to the Ministry of Environment and Forests of the Delhi government and the Delhi Pollution Control Committee (DPCC), while posting the matter for October 9.

“While issuing a notice, we direct all concerned authorities (Delhi government, DPCC, Commissioner of Police) to ensure that no illegal mining is carried out on the Yamuna riverbed and no mining is permitted without obtaining environmental clearance and consent of DPCC,” the bench said.

The order comes after a petition by Rahul Nagar alleged that “illegal sand mining continues unabated under the nose of government officials”. The petitioner has also placed before the NGT “photographs of the trucks which are carrying illegally extracted sand from the riverbed of the Yamuna”. It states that the Irrigation and Flood Control Department in Delhi had issued letters to the Delhi Police, requesting it to take action against the sand mafia.

The petition also claims that illegal sand mining in the area had begun to trespass private agricultural fields located near the floodplains and increased chances of flooding.

“There is a need to study the impact of sand mining, the deterioration caused and remedial measures. Illegal mining has already led to devastating consequences in the region. It has changed river hydrology and affected the groundwater,” the petition stated.

ENVIRONMENTAL DAMAGE

* Increase in river gradient, resulting in excessive sediment transport, erosion and damage to instream habitat

* Bank erosion and change of morphology of the river can destroy habitat on river bank

* Degradation of land

* Lowering of riverbed level and groundwater table due to excessive extraction of groundwater from adjacent areas

* Depletion of groundwater due to excessive pumping during sand mining

* Polluting groundwater through pollutants caused due to mining, such as washing of mining materials, waste disposal, diesel and

vehicular oil lubricants

* Choking of filter materials for ingress of ground water from river