An American woman claims an airline has dumped human faeces on her car and driveway, and on more than one occasion.

Bethany Bowker, who lives 15 miles south of Salt Lake City Airport, Utah, took footage of the aftermath of what she claimed was the result of an aeroplane dumping its toilet waste over her driveway. The video shows her white Cadillac SUV covered in a dark brown substance which she describes as "poop". She says it is not the first time her vehicle and property have suffered such an attack.

"OK, it's 3 January, Tuesday, and I don't know if you can see this – it's poop from an aeroplane. It's all over my driveway... I don't even want to walk out here. All those little brown things are poop. They dumped all of the poop out of the aeroplane and it landed in my driveway."

Pointing the camera at her four-wheel drive, where vast smatterings of the apparent defecation are clearly visible on her bonnet, mirrors and windshield, she says: "All down here, all down here, this is all poop. Human poop... my car is covered in human crap, it's everywhere, my car, splattered, everywhere.

"This is not the first time I've had this happen but this is the worst. I'm tired of this. I don't understand why airlines can get away with dumping their human waste in my yard. Look at this all over my windshield all, over my headlights, oh gosh! It just makes me sick.

"It's human poop smeared all over everything. I want some answers - why in the world would they be doing this?" she said.

The video then ends abruptly when a neighbour calls "Bethany" and Bowker jovially replies "How are you?"

The Federal Aviation Authority website says: "Some aircraft lavatory holding tanks have a blue chemical added to the water to deodorise the water and break down solid waste. Occasionally, the holding tank or drain tube develops a leak. If this happens at high altitudes, the water will freeze once it hits outside air.

"However, if blue ice falls from an aircraft, the ice will usually break up and melt before it hits the ground. If the ice doesn't fall off, it will melt as the airplane descends for landing. Then it usually dissipates into small droplets.

"Many people assume that aircraft lavatories dump overboard when they are flushed; they do not. The aircrew cannot dump the wastewater in flight because the waste valve is located on the exterior of the aircraft and only ground crew can operate valve."