The water quality log (right) shows a high nitrate water in flow/crossflow in an exploration borehole. The high level of dissolved oxygen would suggest that this water originated from near to the surface. The caliper log shows a large fissure corresponding with the nitrate and oxygen highs, which would indicate that this broken section of formation is the source of the nitrate. The results of the logging allowed the production borehole construction to be optimised so that this fractured formation, producing high nitrate surface water, could be cased out ensuring only water with a much lower nitrate content
was produced.

Advantages of Nitrate Logging:
Quicker and cheaper than taking core or water samples for
chemical analysis.
Instant results on site, water column is profiled. 
Repeatable techniques for
borehole monitoring.