Dairy farms are polluters. In addition to the greenhouse gas emissions of all those cows (something farmers refuse to take responsibility for, and will be forcing us to pay for for at least the next five years), there are also the issues of direct and indirect pollution from effluent. Cows shit, and the shit has to go somewhere. And if its not handled properly, you get polluted waterways and aquifers, algal blooms, and water that is unsafe to drink or swim in.
Theoretically, this is all controlled under the RMA. But many farmers don't give a damn about complying with the law. Some councils, such as the farmer-dominated Canterbury Regional Council, just shrug their shoulders at this, and allow them to get away with it - a "strategy" which does nothing to solve the actual problem. But in Otago, they've hit on a different solution: they're actually prosecuting people. 24 Otago dairy farmers are currently being prosecuted for failing to comply with effluent standards. Depending on what section of the RMA they're prosecuted under, they could be facing fines of up to $200,000, or even imprisonment.
Every local authority should be doing this. Firstly, because farmers will not spend the money to comply with the law unless given an incentive to do so, and the threat of serious fines is there to provide that incentive. And secondly, because gross environmental pollution is a crime, which needs to be punished.
