SEWAGE DEPARTMENT TRAINING PROGRAM
How to Build a Free Access Gravity Sandfilter
A Free Access Gravity Sandfilter provides advanced treatment of the sewage effluent before its ultimate disposal in an at-grade absorption area, a drip irrigation absorption area, individual residential spray irrigation system spray field, or another appropriate method of effluent disposal.
Red indicates the location of the sandfilter in an at-grade, spray irrigation, and drip irrigation system.
Free access gravity sandfilters should not be confused with effluent filters that generally are found in the septic tank.
Typical effluent filter.
