Aberfan disaster/Talk

Since this is such a minor comment, I recommend that it be removed once my question has been answered.

What is a 'waste tip'? What is a 'tip' in general? Something containing enough water to kill people, and perhaps someing to do with coal mining?

Is there a different term for this in American English?

--Jimbo Wales

It's a heap where garbage (waste) has been tipped out of a truck or a wheelbarrow or something onto the ground. The waste at Aberfan was waste rock from the coal mines. It had been tipped close to the village school. I don't know if there's an American term for it. -- Derek Ross