How long should you wait after the end of a heavy rainfall event to conduct soil gas vapour monitoring?
1) 8 hours for coarse grained soils
2) 1 week for fine grained soils
3) Several days for coarse grained soils
4) Several days for fine grained soils
5) 1 day for coarse grained soils
6) 8 hours for coarse fine grained soils
7) 1 week for coarse grained soils
8) 1 day for fine grained soils