Woodland, Calif.-Hazardous materials investigators are still looking into an ammonia release at about 9 a.m. Dec. 11 from Agriform Farm Supply Inc. that caused at least 10 residents respiratory problems and sent two of them to the hospital for observation. Investigators told Green Markets the Agriform fertilizer manufacturing plant was producing ammonium polyphosphate by combining anhydrous ammonia and phosphoric acid in a reactor when an operator error triggered the release of a hot puff of ammonia. The ammonia drifted for up to a half mile before it was cooled by a weather inversion and dropped back down. Lead investigator Jeff Pinnow, a Yolo County hazard materials specialist, declined to provide more details on the incident, except that the operation was using the so-called “TVA process” developed in the late 1950s, which combines anhydrous ammonia and phosphoric acid with water to make 10-34-0 liquid fertilizer that goes into bulk storage. Pinnow said he expects a final report to be ready in a few days. No one was available to answer questions at the Agriform plant, but Yolo County Director of Environmental Health Bruce Sarazin reported that Agriform has had numerous releases in the past and was ordered to stop the operation until the problem was corrected. “They brought in new equipment, and then had another release,” Sarazin said. “There’s at least a possibility of citations, but they’re a good local business and we don’t want to run them out of town. Still, they need to understand their responsibility handling toxic gas.” Woodland Fire Battalion Chief Ken Bechtold said that Agriform had all necessary air quality permits to perform the ammonium polyphosphate process within legal limits. “They’ve been doing this operation for 20 years,” Bechtold said. “But the weather conditions were just wrong for what they were doing. The cold air inversion didn’t allow the cloud to dissipate and some of the ammonia condensed and came back down.”
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