Environmental groups and the state opposition are calling for the O'Farrell government to act after energy producer Santos was fined for contaminating a northwest NSW aquifer, reportedly with uranium.

The Environment Protection Authority issued a $1500 fine to Santos last month following the "pollution incident" at the company's Narrabri Gas Field operations in the Pilliga.

In waiting: Grazier and protester Ted Borowski lies in a dry creek bed ready to disrupt a drilling convey in the Pilliga forest by locking himself to a truck. Credit:Dean Sewell

Fairfax Media reported that the aquifer was contaminated with uranium at levels 20 times higher than safe drinking water guidelines.

The contamination is said to have been caused by water leaking from a pond, with lead, aluminium, arsenic, barium, boron, nickel and uranium detected in the aquifer at elevated levels.