Neighbors in and around Lincoln County’s Mill Canyon reached an agreement that will allow treated sewer sludge to be applied to some agricultural land outside a key watershed.

The Washington Department of Ecology issued a permit this month that allows an Onalaska-based business, Fire Mountain Farms, to spread the treated sludge, known as biosolids, on a farm above the canyon. But the amount of land that can be treated with the fertilizer is 158 acres, a significant reduction from the original request to be able to spread it on 887 acres.

The land on Rosman Farms that can be fertilized with the biosolids is some five miles from the canyon and a source drinking water for some of the residents and irrigation water for some small organic farms. The original request was to allow it to be spread on land within about a mile of that water source

The use of treated sewer sludge is legal with the proper Ecology Department permit that sets up U.S. Environmental Protection Agency restrictions on when and how often they can be applied. Under those conditions, the department classifies them as a “beneficial resource” using a product that is generated by sewage treatment plants

But residents who formed the Protect Mill Canyon Watershed argued that they aren’t safe and used studies conducted by Seattle-based microbiologist Richard Honour, who said the substance can be high in E.coli and other infectious disease agents that multiply quickly in damp materials.

Some studies say they also can contain toxic metals and chemicals.

Because of the dispute, the permit was delayed for about two years for additional hearings and comments.

Morton Alexander, a resident of the canyon and a member of the watershed group, said the dispute was eventually settled with negotiations between neighbors. With the deadline for the department to issue a permit approaching, some of the canyon residents met several times with the farmer, Gary Rosman, who eventually agreed to limit the biosolid fertilizer to an area far from the canyon.