The Delhi high court has asked the ministry of environment, Central Pollution Control Board and other concerned departments to reply to a petition filed against dumping of fly ash in the capital. The court issued the notices in response to a writ petition filed by judicial activist B L Wadhera. The petitioner said the fly ash disposed in various dumping grounds in the city was being blown away by the wind and posing health hazards to people living in neighbouring areas. The director of the fly ash mission in the department of science and technology, who was present in the court, said that laboratory tests had proved the multipurpose use of the ash.