Horowhenua District Council has approved an application to build what could become the country's biggest piggery on a dairy farm near Foxton.
It has imposed strict conditions on the construction and operation of the piggery.
The facility will not be able to expand to its planned full size without a consents review.
The piggery will cover a 50-hectare site on Coastal Lakes Station, a large coastal farm between Foxton and Himitangi beaches.
Owner Graham Sexton says his aim in adding a piggery to an existing dairy farming operation is to diversify and secure the future of the farm.
It would initially run more than 3000 breeding sows, a figure that would increase to 4800 if the expansion was approved.
Effluent from the piggery will be treated and used as fertiliser on the station, requiring a separate discharge consent from Horizons Regional Council.
The hearing commissioner who approved the proposal expects conditions about odour, noise and traffic control that are imposed on the development to cover the concerns raised by a number of residents nearby who opposed the application.