Case 1 Filter layer
The use of Geosynthetics leads to lower impact in all categories:
The greenhouse gas emissions for geosynthetic filters are only 10,4% as compared to a mineral filter.
The non-renewable cumulative energy demand for construction of 1 square meter filter (30 years) is only 19 MJ-eq (131 MJ-eq for mineral filter), almost 7 times lower.
At the same time, the use of geosynthetics generate cost savings (see graph below)
Filter system below a road:
Case 1A - granular filter layer - 300 mm gravel
Case 1B - geotextile filter – 175 g/m2
Hydraulic permeability: (k-value) ≥ 0.1 mm/s
Estimated lifetime ≥ 30 years
Filter system below a road
Drainage trench construction