Lou:

Wow, somehow missed this post last month but Matt is right. The answer to your original question is zero. According to the Federal Clean Water Act, which is where the NPDES and stormwater rules are based, no sedimentation may occur off the property or to "waters of the state". You did them a big favor by not reporting them to the enforcing agency immediately.

This is probably the most frequently ignored environmental regulation out there by both contractors and regulators. The favored techniques are always to prevent erosion before it occurs because it is much more difficult and costly to deal with sedimentation after the fact. You might want to sample your pond bottom and determine how much sedimentation has occurred (you might be surprised).

As you say, there are many management practices. I literally have volumes of information here on my desk regarding soil erosion and sedimentation control bmp's and procedures. You are much more patient and understanding than I am and should not have had to spend a dime on this.