Gas spike surveys and wells in trial pits

Driiied weii in sheii and auger borehoie with standpipe covering severai strata max depth around 30 m (Greater depths require increased diameter) 

Drilled well in shell and auger borehole with standpipe covering single stratum 

Hand driven spike hole Maximum depth around 1 m 

Main plastic casing Perforated plastic casing 19 mm to 100 mm diameter, typically 50 mm 

Temporary casing with gas tap may be installed but difficult to seal and limited depth 

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