Items I believe you should consider. (Not knowing your exact operation).

1. I assume that you have NOT found any evidence/documentation left by your predecessor(s) as to why the log file is at its current size.

2. Are there any periodic (end of month / end of quarter / end of year / large imports of data) operations (reports etc.) that would require such a large log file or cause a smaller log file size to grow to what you now have?

3. Do you have any desperate need for the disc space that would be "freed up" ?