U-21P Following preliminary pad location, the permittee will allow 



the land manager 14 days to conduct a field survey to determine 

 the ecological significance of the area. Should an important 

 or unusual ecological feature be encountered, the permittee 

 agrees to relocate the wellsite and well pad to an extent reason- 

 ably necessary to protect critical plant assemblages, unique 

 natural areas, critical wildlife areas, or other desirable eco- 

 logical features. 



U-23P The permittee shall provide the land manager with a design 



which restricts the pad size to the minimum area required to 

 conduct drilling operations, store equipment and supplies, and 

 contain waste materials. Pad easement shall not exceed 10,000 

 m (2.5 acres), unless otherwise authorized by the land manager. 



Mud and waste management. 



U-27P The permittee agrees to use portable mud tanks in connection 

 with the drilling operations in place of an earthen mud pit. 

 If earthen pits are required, they will be lined to prevent 

 seepage or leakage of pit materials into the soil. 



U-29P All drilling mud, drilling wastes, equipment leakage, and other 

 petrochemical substances shall be collected and centrally stored 

 in impervious containers. Wastes shall be immediately disposed 

 of off the refuge following completion of drilling operations. 

 Waste disposal on the refuge is prohibited. 



U-30P No drilling equipment or processes of such quality and type that 

 permit or cause the release of oil, field brine, or other oil 

 field contaminants or pollutants into the environment shall be 

 utilized on the refuge. 



Surface damage. 



U-25P All existing drainage patterns within the pad-site easement shall 

 be maintained uninterrupted, by the use of conduit, culverts, 

 or other applicable techniques as specified and authorized by 

 the land manager. 



U-26P The permittee shall take such measures to prevent soil erosion 



from starting within the entire easement area and still implement 

 prescribed conservation measures, including restoration of dis- 

 turbed ground surfaces, mulching, and revegetation, that may be 

 requested by the land manager. 



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