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Mr. Steven G. Renner 2 2 of 4 - The initial response from MLRD indicated that a letter to the permittee would be sent requiring a revision to the permit that would satisfy the demonstration requirement for small area exemptions (SAE). The second response from MLRD included the letter sent to the permittee. AFO has reviewed the document and finds it to be appropriate. The timeframes specified for revising the permit are within the timeframes established by INE-35. 3 of 4 - The initial response from MLRD requested an additional 10 days to evaluate the regulatory requirement in regard to impoundments. The second response from MI.RD is also a request for additional time and a request for additional clarification on the issue. The cited structures have been called sumps. The regulations do not define or strictly address such features. The regulations do distinguish between a small depression and an impoundment by limiting the size of small depressions to one cubic yard of impounded runoff. Comments on the restrictive size were received and OSM responded, "Since a paragraph addressing impoundments is now incorporated in the regulations, the limit remains appropriate to distinguish between surface manipulations that assist with revegetation and erosion control by impounding small amounts of water in confined areas and those impoundments that may affect the area and which must therefore receive special consideration by the regulatory authority * * *" 42 Federal Register 62645. As a primary concern though, one must consider the intended usage of such a feature. The MI.RD regulation at Section 1.04(64) defines an impoundment as a closed basin, either naturally formed or artificially built, which is built to or does in fact retain water, sediment, or slurried waste. Section 1.04(115) defines a sedimentation pond as a primary sediment control structure. All of the structures cited are the last sediment control structures that disturbed area runoff will drain through prior to discharge onto an undisturbed area or into the Purgatoire River. This section continues on to further define sedimentation ponds as barriers, dams, excavated depressions, etc., that slow down runoff water to allow sediment to settle out. All of the structures cited were constructed for that purpose. Three of the structures have designs to show that the 10-year, 24-hour event will be completely contained by the structure. The other two were constructed, with apparent tacit approval by MLRD, because they are shown on location maps but are not addressed in the permit narrative, at the operators discretion in sizing, etc. These two structures, or other sediment control structures in these locations, must be specifically approved. The OSM inspector was told that the structures have functioned to completely contain runoff events thus far until the water evaporates. All five of the cited structures fall under the definitions of impoundments and sedimentation ponds.