A Washington state appeals court has struck down a local ban on the recycling of biosolids.

The Washington Court of Appeals issued a 3-0 ruling to overturn an ordinance in Wahkiakum County that banned the land application of Class B biosolids. The court sided with the Washington Department of Ecology that state law encouraged recycling biosolids to the soil, and localities could not overrule a state program. A trial court upheld the original law.

In the appeals court decision Judge Linda Lee wrote that the purpose of the state biosolids program “is to recycle sewage sludge by retreating it as a beneficial commodity in land applications in agriculture, silviculture and in landscapes as a soil conditioner. . . . Farmers have come to rely on the well-established and uniform state regulation of land application of biosolids for planning and investment.”

Wahkiakum County, in southwest Washington, passed the law in 2011 banning land application of Class B biosolids, the predominant type of biosolids generated by wastewater treatment plants in the state.

The Washington Department of Ecology was supported in its appeal by several groups, including farmers using biosolids, the Washington Association of Sewer and Water Districts, the Northwest Biosolids Management Association and the National Association of Clean Water Agencies, according to an e-mail from Jimmy Slaughter, counsel for several of those groups.