A former senior armyman has moved the National Green Tribunal alleging dumping of human waste by aircraft over residential areas near the IGI airport here, which led the green panel to order an inspection of his South Delhi house.

Lt Gen (Retd) Satwant Singh Dahiya has sought criminal proceedings against commercial airlines and levy of hefty fines on them for endangering the health of residents, terming the act as violation of the Swachh Bharat Abhiyan.

Noting the submissions of the petitioner, the green panel directed Central Pollution Control Board (CPCB) to depute a senior environmental engineer to inspect his house and check the existence of human excreta on the walls.

It also asked CPCB that if excreta was found, samples should be collected for analysis and the report placed before the tribunal.

A bench headed by NGT Chairperson Justice Swatanter Kumar also issued notices to the Ministries of Environment and Forests and Civil Aviation and CPCB, seeking their replies within two weeks.

Plane toilets store human waste in special tanks. These are normally disposed of by ground crew once the plane lands, but aviation officials acknowledge that lavatory leaks can occur in the air at times. There have been instances, including in India, when people have been injured.

In his petition, Vasant Enclave resident Dahiya has sought creation of a 24-hour helpline for immediate reporting of the incident and a monitoring mechanism to check that no aircraft drops "human soil or excreta" while landing.

"For past more than the week in the early morning, we found that walls and floors of terrace of our house splattered with large patches of excreta dumped by aircraft flying in front of Palam airport at night. This is the second time this has happened. Last time it had occurred in early October when we had spent Rs 50,000 to get the entire exterior resurfaced with fresh paint.

"Diwali is only few days away and being the festive season having recently finished fresh coating of the house exterior at considerable experience to clean up the premises. We are again faced with having our walls completed spattered with waste. We are retired people and cannot afford to have this defacement everyday," the plea said.

The bench, also comprising U D Salvi, said "We direct senior environmental engineer from CPCB to visit the premises of the applicant and check whether as a matter of fact remnant of human excreta are found on the walls or on terrace floor of the applicant's building or any building adjacent thereto.

"If the remnants are found, its samples should be collected for analysis in order to confirm its nature and analysis report be placed before the Tribunal on the next date of hearing" on November 25.

Advocate B V Niren, appearing for Civil Aviation Ministry, opposed the argument and said plane toilets stored the waste in special tanks which are normally disposed of by ground crews once the plane lands.

In January this year, a woman in a village near Bhopal suffered injuries when a frozen mass bounced off a nearby building and fractured her shoulder.

Aviation experts then believed that the mass could have been either blue ice, a term used to describe sewage leaked form an aircraft lavatory, or a megacryometeor - an extremely large chunk of ice formed under unusual conditions.

Similar incidents have been reported from the US and the UK too.