REP41933

• Permit No: C1981041
• IBM Index Class Name: Report
• Doc Date: 10/21/1997
• Doc Name: FAX COVER
• From: DMG
• To: OSM
• Permit Index Doc Type: Waste Pile/Fill Report
• Media Type: D
• Archive: No

CRDA-1 are judged to be in compliance with the approved plan.
Transect 1 starting point .was at the crest of the bare refuse
outslope of Bench #4, approximately 75 yards northwest of the
southeast corner of the refuse pile. The transect extended to the
base of the pile, and included Terrace Drains 1, 2, and 3. The
bare refuse outslope of Bench #4 had a gradient of 40%, and height
of 32.6'. Terrace Drain #3 width--10.5', 12% slope to inside, 3%
slope along drain to the southeast. Reclaimed Bench 3 outslope
gradient--40%; bench 3 height--34.1'. Terrace Drain #2 width--13',
5% slope to inside, 2-3% slope along ditch to southeast. Reclaimed
Bench 2 outslope gradient--40%; Bench 2 height--31.8'. Terrace
Drain #1 width--14', 7% slope to inside, 2% slope along drain to
southeast. Reclaimed Bench 1 outslope gradient--44%; Bench 1
height--39.9'.
Transect 2 starting point was at Terrace Drain #3, approximately
150 yards east of the Northwest Collection Ditch. The transect
extended to the base of the pile, and included Terrace Drains 1, 2,
and 3. Terrace Drain #3 width--10' , 15% slope to inside, 1-2 %
slope along drain toward Northwest Collection Ditch. Reclaimed
Bench 3 outslope gradient--42%, height 31.9'. Terrace Drain #2
width--14.5', slope to inside--7%, slope along ditch to NW
Collection Ditch--1-2%. Reclaimed Bench 2 outslope gradient--40%,
height--37.1'. Terrace Drain #1 width--12.5', 6% slope to inside,
2-3% slope along drain to NW Collection Ditch. Reclaimed Bench 1
outslope gradient--45%, Bench i height--30'.
Refuse Area Collection and Diversion Ditch Evaluation
SEDCAD summary and printouts are included as Attachment 2;
September 12, 1997 memo from Erica Crosby to Dan Mathews. Ditch
measurements are presented below.
CRDA #2 East and West Collection Ditches
Permit Exhibit 53 design for perimeter ditches specifies
trapezoidal shape with 3' bottom width (bw), 8.7' top width
(tw), and 17" depth (d) for 3% gradient segments. A separate
design for 33% ditch gradient segments specifies 3' bw, 6.5'
tw, and 11" d. Segments with gradient between the two
extremes would be allowed to vary with respect to top width
between 6.5' and 8.7', and with respect to depth between 11"
and 17", depending on slope. Ditch measurements were taken at
multiple locations and SEDCAD computer software was used to
evaluate apparent capability of ditches to convey 100 year/24
hour design flows. One problem was identified with respect to
the ditch segment represented by DM/6, which may require
permit amendment and ditch modification.