Confined space manure storage and facilities safety assessment

A mail survey of 1,200 farms across 16 states was conducted to identify the number, type, and size of manure storages per farm, as well as safety-related behaviors or actions related to entry into confined-space manure storage and handling facilities. Respondents provided data on 297 storage units and facilities, with approximately 75% reporting up to three storages per farm operation. Dimensions were provided for 254 manure pits: nearly 66% were less than or equal to 100 feet long, 75% were less than or equal to 40 feet wide, and 75% were less than or equal to 10 feet deep. Almost 14% of the reported storages were over 300 feet long, seven were wider than 100 feet, and 17 were more than 20 feet deep. Survey results suggest that most farm operations with confined-space manure storages do not follow best safety practices regarding their manure storages, including using gas detection equipment before entering a manure pit, using rescue lines when entering storages, or developing a written confined-space safety policy or plan. Survey results also suggest that few farmers post warning signs around their storages, post recommended ventilation times before entry, or conduct training for workers who enter confined-space manure storages. This article provides a benchmark against which the effectiveness of educational programs and design tools for confined-space manure pit ventilation systems and other confined-space manure pit safety interventions can be measured.