NRCS concluded that it would not and the Chief of NRCS issued a finding of no significant impact on May 20, 1997.
The Chief of NRCS found some impact, but it was not significant. 
mnli hypothesis: The Chief of NRCS found some impact, but it was not significant.  premise: NRCS concluded that it would not and the Chief of NRCS issued a finding of no significant impact on May 20, 1997.