Slurry & Manure
750-cow dairy wins back its slurry storage: bottom solids had cut a 6–12 month store to 3–4 months.
Wolfe Power Line Dairy, 750 cows · Milton, Pennsylvania, USA · 22 October 2026
The challenge
The store was designed to hold six to twelve months of slurry, but bottom solids had blocked the inflow and reduced it to three or four months. Ray Wolfe also wanted rid of the surface crust and the odour in the barn and at spreading, both of which were major concerns.
The approach
In June 2002, after a normal pump-down, 12 gallons of MICROBE-LIFT®/DFP went in through the primary manure discharge line. Two gallons a week followed for four weeks, then one and a half gallons a month until the store was next emptied.
Results
Removed
Bottom sludge build-up
Full design capacity back
Storage
Broken down
Surface crust (15–20 in)
No longer needed
Agitation before spreading
The farm met its first goal: the sludge that stopped it using the full store was gone. Odour was noticeably lower in the barn and during spreading, and with the crust broken down there was no need to agitate before land application, saving time and fuel. For a Northern Ireland farm that has to hold slurry through the closed period, getting back storage it already owns can matter more than anything else. Ecological Laboratories present this as one farm's field report, and results vary with the system.
Source documentation
Ecological Laboratories case studies (opens in a new tab)