Considerations of Pull-Plug Sedimentation Basin for Dairy Manure Management
This webpage currently provides only an introduction to this guide. Please download the PDF for the complete guide.
Extension Specialist, Agricultural Systems Management
Teng Teeh Lim
Associate Professor, Agricultural Systems Management
Environmental Engineer, USDA-NRCS
Many small dairy farms have limited practical and easy-to-operate options for manure management. A flush system for manure removal is attractive due to reduced chore time and increased barn cleanliness. However, flush systems require greater attention to onsite water management that result from having to store water with high nutrient and solids concentrations.
There are several different types of lagoons commonly employed for agricultural use. Lagoons designed for treatment and solids reduction via digestion can be aerobic or facultative/anaerobic. Anaerobic treatment lagoons can be ideal for many agricultural applications when it comes to water and manure management. The lagoon, typically 8–15 feet deep, provides some digestion of manure solids while serving as a holding basin when land application is not possible due to frozen ground or saturated soils. Storage lagoons are another type that aren’t designed for the purpose of solids reduction but, rather, for holding water or a water and solids slurry in order to better manage the on-farm water inventory. A portion of lagoon volume is designated for holding solids, regardless of the purpose or type of the lagoon. Solids removal prior to a lagoon may help increase lagoon capacity and reduce, if not eliminate, the need for costly lagoon dredging.
The pull-plug sedimentation basin (PPSB) is a passive solids removal system that can reduce the operational time and cost of the overall manure management system by acting as both a sedimentation basin and pre-lagoon solids filter system. Larger, denser particles (e.g., gravel, grit, and sand) accumulate on the basin floor, while buoyant particles (e.g., undigested fiber, waste forage, bedding, etc.) form a floating mat on the surface. The mat acts as a natural filter and allows the PPSB to retain up to 90% of the solids from the waste stream.
The PPSB is installed between the flushed freestall barn and the lagoon, as seen in Figure 1. Figure 1 shows one of several possible arrangements of a PPSB relative to the overall facility. Various configurations are discussed in the Design Considerations section. A sand settling lane can be integrated into the design between the freestall barn and the PPSB if needed.
Figure 1. Placement of a PPSB within the flush system on a dairy farm (drawing not to scale).
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