Birds are another kind of vermin. Seagulls defecate "en masse" on their paddocks, and some peck out the eyes of newborn lambs. One of their neighbours has moved his lambing to prevent that.
The O'Neills can smell the landfill everywhere on their property, but they especially notice it in their house.
"It's a pretty putrid smell. We aren't stupid. We can tell the difference between a silage pit and an effluent pond. Mornings and evenings we can smell it more often, especially if it's still or there's a light easterly," Mrs O'Neill said.
Trees screen the tip face from their house, which is less than 1km away. But they can see it from the rest of the property. It's covered once a week, but very obvious at times.
They can't see the leachate ponds, which are farther away. The effect of landfill leachate on Marton's wastewater treatment system is not being considered at the hearing. But Mrs O'Neill said it was on their minds.
"As ratepayers we are very concerned that we will foot the bill with anything that goes wrong with the sewage treatment in Marton."
If the full expansion happens the tip face will be closer to their house and a new hill, higher than anything else around it, will become part of their landscape.
The site looks tidy and people driving by only experience a brief smell from it. But Mrs O'Neill said living with it all the time was different.
"We aren't irrational about this. We understand that we need some increase in size. But nobody wants it in their back yard."