The site. Red Hill Poultry Farm near Pattingham. The foul drainage was being upgraded and needed to discharge treated effluent to ground through a drainage field.
What we did. Infiltration testing to the BS 6297 method referenced by Part H of the Building Regulations, which is the test used to size a foul drainage field, at the proposed drainage field location.
What we found. The ground was suitable for infiltration.
What it meant. The engineer could size a drainage field for the treatment plant, the most efficient way to discharge treated foul effluent where there is no mains sewer.
The lesson. Foul and surface water tests are different tests with different methods. Many rural sites need both, and we can do them on one visit.