Bhubaneswar, Sept. 29: Authorities of Biju Patnaik International Airport are blaming the municipal corporation for lack of cleanliness around the runway - that is making the planes vulnerable to bird hits.

In many parts of the airport, the grass has grown taller than six feet and is not being pruned regularly. This makes the area an ideal nesting ground for birds. Also, contractors engaged in cutting the grass tend to dump it inside the airport.

"The cut grasses should be thrown outside, and after cutting, herbicide chemicals should be sprayed. All this should be done before the monsoon, but at the city airport, the cutting is not yet over," said a well-known biologist, who is member of an expert committee engaged by the Airports Authority of India to submit a status report on the bird species in the area.

The expert, who did not want to be named, said: "We have warned the airport authorities that it was important to keep the area clean to keep birds at bay. It was proposed to use herbicides, so that the grass is killed. But as the birds are affected by their poison, it would be safe if they are caught and released elsewhere."

The AAI was also told by the experts to trim trees near the runway as some of them have huge nests of birds such as kites on trees near the old terminal, which now functions as the international terminal.

"We are cutting the grass periodically, but the herbicide had not been applied before the monsoon because there was the possibility of it being washed away by rainwater. We have warned the staff members and contractor associated with grass cutting to work properly or face action for neglect. A deadline of October 15 has been given to finish the work," airport director Sharad Kumar told The Telegraph.

Kumar also said that due to bad drainage, the runway towards the Baramunda-end was getting waterlogged and attracting birds. However, the state government said this problem would be fixed. Last month, a portion of the airport boundary wall had to be repaired after it had been damaged by rainwater.