DES MOINES, Iowa (AP) — One of the nation’s largest egg farms, which lost millions of hens in last year’s bird flu outbreak, is defending itself against legal action by the state over a wastewater spill that killed 163,000 fish.

The Environmental Protection Commission has referred Sunrise Farms to the attorney general for enforcement of violations of state laws and administrative regulations regarding the contamination of about 18 miles of Stoney Creek. The company owns egg-laying barns near Harris designed to hold up to 8 million hens.

An attorney for Sunrise Farms, an affiliate of South Dakota-based Sonstegard Foods, says the wastewater discharge happened a few months after the bird flu outbreak destroyed 3.8 million chickens and the farm was dealing with production issues it had never before experienced.