It may not be possible for all and sundry to exploit the Capital's ground water if the Central Ground Water Authority goes ahead with its proposal to restrict exploitation of ground water in Delhi in view of the receding water level. The restrictions are expected to include a complete ban on extraction of water through bore-wells in specific areas where the level has dipped too low. Among those who are expected to be hit hardest by the authority's decision are industrial units and those in the business of marketing water. "Some restrictions will have to be placed. We cannot ignore the over all drinking water scarcity," a senior official said. The CGWA had recently asked people drawing ground water to register with them.