Trisoplast is a mineral barrier material composed of sand, bentonite (> 10.7%) and a non-biodegradable polymer. Its permeability is less than 3 x 10 -11 m/s , which in general is not seriously affected by external physico-chemical influences. Trisoplast barriers, installed in 1995-1996 were excavated to check the occurrence and potential effects of ageing phenomena in situ. Incidentally root penetration in Trisoplast was observed, which obviously had not caused visible desiccation and crack formation. The actual permeability had not changed significantly since the installation. The safety factor of the barriers according to the regulations in the Netherlands actually varies from 2.1 to 10.2 and it is expected that due to possible future worst-case conditions the variation can drop to 2.2-6.4. As this is still above the required value of 1, Trisoplast is sustainable at these sites. The average infiltration rate derived from water and salt-balances of the barriers without a geomembrane, ranges from 1to 2 mm annually and only amounts to 5-10% of the permitted maximum rate of 20 mm annually.
|Place of Publication||Wageningen|
|Number of pages||163|
|Publication status||Published - 2003|
- soil pollution
- subsurface barriers