The Thane collectorate recently invited bids from private players who are expected to determine the nature and the degree of the effects from sand extractions. Their report will subsequently be used to formulate regulatory requirements for future dredging activities.

The move is in compliance of the recent orders of the Supreme Court which has made it compulsory for all state authorities to conduct an Environmental Impact Assessment Study(EIAS) for sand mining. Till such time that the study report is finalized, all dredging activities have come to a standstill here.

The SC orders comes in the wake of indiscriminate sand dredging from in-stream and floodplain areas leading to severe damages to the creeks and river basin environment. There is complete ignorance on the environmental impact of river sand dredging and the growing demand for sand due to rapid urbanization has resulted in near-zero regulatory environment.

Thane district is one of the major source of sand obtained from four rivers Ulhas, Surya, Vaitarna and Tansa besides the Vasai and Thane creeks. The total area covered by the 47 sand dredging spots is estimated to 107km long in Thane.

A district official said the highest number of dredging sites are located at Vasai creek covering close to 29km, followed by 10 such spots in Vaitarna river which are 24 km long. However, all dredging activity has come to a standstill and has hit the state income to the tune of Rs 1,500 crores.

"The pre-bid documents will have to be submitted by Wednesday and the terms of reference for the EIAS has been listed in detail It is expected that the contractor conducts a spot survey and also speaks to stake-holders including fishermen etc to understand the social impact of the dredging activitites. It is expected that they carry out a complete digital processing of the entire creek and river area using remote sensing technique," he said.