Woodwaste to Wine: A Unique Landfil Closure, 1996 Environmental Conference Proceedings

Louisiana Pacific (LP) operated the York Ranch site near Ukiah, California, to accept sort yard and sawmill debris from its local mill. By 1993 the waste stream was being diverted to other uses, and LP decided to close the 42-acre (17-hectare) landfill. Prescriptive California Chapter 15 closure regulations required a l-foot (30-centimeter [cm])-thick compacted clay cover overlain by 1 foot of topsoil. In lieu of this prescriptive closure, a unique closure was proposed, and eventually constructed, that would convert the landfill into a vineyard. The final cover consisted of 3 to 4 feet (0.9 to 1.2 meters [m]) of site soils, without a clay barrier layer, that would support a vineyard. A downgradient groundwater interception pond upgradient of a slurry cutoff wall was used as justification for the alternative design. A water balance was used to size the pond. The benefits of the final project are that (1) landfill was closed in accordance with state requirements, (2) an expensive (and technically questionable) clay liner was avoided, and (3) the end use of the property met the needs of the land owner.