Starting from Saharanpur and Bijnor where the main Himalayan rivers enter the state and spread across Gautam Buddh Nagar, Agra, Allahabad, Kaushambi, Sonbhadra districts, illegal sand mining is rampant in Uttar Pradesh. The worst loot occurs in the river basins of the Yamuna, Hindon, Betwa, Ken, Chambal and Sone. The sand from these rivers is of high quality and ideal for construction purposes. The boom in infrastructure, real estate and industrial projects has fuelled demand and encouraged black marketing.