It depends on the size of the pond; generally high density polyethylene film of 1.0-1.5 thickness is enough.
A sewage treatment plant also uses geomembrane? That's what a sewage treatment plant used for preventing percolate from filtering, isn't it? It is advisable that a sewage treatment plant should adopt cement which has better impervious performance?
0.75mm to 2mm is workable; the cost performance of 1mm is the highest, so it is most frequently used.
It should not be very high.
