INSPEC43024

• Permit No: C1982057
• IBM Index Class Name: Inspection
• Doc Name: Inspection Report
• Inspection Date: 3/19/2003
• Media Type: D
• Archive: No

III. COMMENTS -COMPLIANCE
Below are comments on the inspection. The comments include discussion of observations made
during the inspection. Comments also describe any enforcement actions taken during the inspection
and the fact or evidence su~~ortinc7 th~ enforcement action.
restore es~gn cross sect ns. lrTSta ,repair or replace riprap as necessary to prevent
erosion from the f0 year 24 hour storm event runoff.
When observed on the morning of April 16, there was snowmelt runoff flow in the ditches
on both sides of Haul Road G, extending from the D Pit areas regraded in summer/fall of
2002, down toward Sediment Pond 005. Flow appeared to be 200 gpm or more in each
ditch. There was significant downcutting along each ditch extending for several hundred
yards from the lower end of the regraded spoils, down to and including a steep down drain
segment below a 36" culvert outlet above Pond 005. In some locations, riprap had been
washed out or undercut, and in other locations flow had bypassed riprap and eroded a gully
along the side of the riprapped channel. Gullying from 1 to 3 feet deep was common, with
the deepest incision along the lower end of the north side ditch relief outlet drain, where the
vertical sided gully appeared to be approximately 10 to 12 feet deep. In one location, just
below the north ditch relief outlet drain, a small sediment check pond had been completely
filled in with sediment and the riprapped spillway and riprapped drainage segment below
had been partially washed out.
Drainage from a large area of the regraded spoil had flowed into the north side road ditch,
rather than into an adjacent natural drainage channel at the lower end of the spoil. The
approved plan appears to have been for the flow to be directed into the natural drainage. It
appeared that the operator had attempted to install temporary berm or diversion features in
the summer or fall of 2002 to divert flow from the spoil into adjacent natural drainages, but
these temporary features were over-whelmed by the snowmelt runoff that found its way
into the north side road ditch. Disturbed flow from both the road ditches and the natural
ephemeral channels in the vicinity is captured by Sediment Pond 005. All of the runoff
associated with the eroded ditches described did end up in Pond 005.
On the morning of April 16, although the disturbed flow entering Pond 005 was highly
sediment laden, the pond discharge outlflow (estimated to be 400 gpm or higher) appeared
relatively clear. snowmelt runoff inflow rate is assumed to have been equivalent to
outlflow, since the discharge was from flow over the top of the primary spillway riser.
Samples 057-005-1 (for total suspended solids) and 057-005-2 (for total settleable solids)
were taken from the discharge outlet at 4:15 p.m., on April 16. The samples were kept in
my possession in an iced cooler, and delivered to Brian Bauer at Grand Juriciion
Laboratories in Grand Junction, at 9:00 a.m., on April 18.
Regulation sections cited included various provisions of Rule 4.03.1 pertaining to general
haul road construction and maintenance; as well as construction, maintenance, and erosion
control requirements pertaining to disturbed area haul road drainage structures. Provisions
of 4.14.1(2)(b) and 4.14.2(5) were also cited, due to the observations indicating that
improper spoil grading had (apparently unintentionally) concentrated flow within road ditch
segments, almost certainly exacerbating ditch erosion.
Permit Sections cited were Exhibits 13-2,13-10, and 20-2. Exhibit 13-2 is titled Surface
Hydrology Map, certification date of Dec. 7, 1998. The map depicts Haul Road G ditches
above the 36" culvert as Category "C" ditches. Exhibit 13-10 is titled Typical Road
Details, certification date of Nov. 5, 1990. The exhibit specifies that roadside ditches
would be constructed as "V" ditches with 2:1 side slopes. Category "C" ditches are
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