2009-11-24_INSPECTION - C1981019

Home Browse Search

Colowyo C- 1981 -019 10 Nov 2009 Pg 4/7 Hydrologic Balance (cont.): - The Streeter Pond (NPDES 001 A) contained water approximately two feet below the top of the discharge pipe and was discharging through the weep hole at the time of the inspection. The discharge looked clear at the flume. The Streeter Pond discharges into the Goodspring Creek and flows through a large CDOT culvert under Colorado Highway 13. There was no sediment at the inlet of the pond. The outslopes of the embankment were stable and well vegetated. The top of the embankment was left in a roughened state following the cleaning last winter. This embankment was inadvertently graded smooth by Anson a few days earlier. Following the grading of the embankment, there is no vegetation on the top of the embankment. If no vegetation grows this spring (from seed and grasses that remain) Colowyo will need to reseed it to ensure its stability. - The Work Area Pond (NPDES 002A) contained water approximately three feet below the top of the discharge pipe and approximately 18 inches below the weep hole and was not discharging at the time of the inspection. There was water flowing into the pond at the inlet on the northeast side of the pond. The embankment was well vegetated and stable and no erosional problems were noted. - The Wash Bay Pond (not and NPDES discharge point) contained water approximately five feet below the top of the embankment and was not discharging at the time of the inspection. This pond is a total containment pond and any discharge into the Work Area Pond would require BTEX testing. Water from this pond is used for dust suppression on the haul roads. The pond embankment was well vegetated and stable and no erosional problems were noted. The presettling pond (by the wash bay) was basically full but was not discharging into the main pond. This pond was cleaned out and all of the sediment is piled up by the edges of the pond. This material should be removed to the pit before it ends up back in the presettling pond. - The newly constructed lower portions of the Final East Pit Ditch and the North Tributary, East Pit Ditch remained stable. These ditches will capture all of the runoff from the south portion of the Prospect watershed and carry it to the South Collection Ditch (and ultimately to the Prospect Pond. - The newly constructed lower portion of the Taylor Tributary Ditch in the West Pit remains stable. This ditch will convey water from the west half of the East Taylor watershed into the East Taylor Pond. - The Prospect Ditch was walked from station 0 +00 to approximately 25 +00. There is one portion of this ditch, from approximately station 6 +00 to approximately station 9 +00 that has not yet been completed. It will be completed with the scheduled backfilling in 2010. Upon completion of the Prospect Ditch in 2010, Colowyo must provide the Division with an as -built map of the ditch. All East Pit runoff above station 6 +00 flows into the East Pit and all runoff below station 6 +00 flows into the Prospect Pond. Elevation readings were taken at 28 locations along the length of the ditch to create a ditch profile. This profile was compared with the designed ditch profile. The Division's profile appears to correlate with the designed profile for the portion of the Prospect Ditch that was walked. Please see the channel profile and the data at the end of this inspection report. All elevations were taken with a Trimble GeoXT and are relative elevations, as they were not based on a control point.