Dirty dairying, effluent disposal, chemical pollution. All these environmental harms are supposed to policed by the Resource Management Act (RMA). But the RMA doesn’t stop pollution: it licenses it.
So too does the American EPA. (Only it doesn’t just license pollution—it pollutes waterways itself!)
But long before we had the RMA and Americans had the EPS, pollution was controlled by the common law, and had done successfully for several hundred years.. Here’s a quick video explanation. It’s American-based, so it talks EPA. And it’s short—so even Americans can understand it. So you should have no problems at all.