2011-11-30_PERMIT FILE - C1981008A ‎(5)‎

• Permit No: C1981008A
• IBM Index Class Name: Permit File
• Doc Date: 11/30/2011
• Doc Name: Pond 015-As Built ‎(TR60)‎
• Section_Exhibit Name: Section 2.05.3‎(3)‎ Attachment 2.05.3‎(3)‎-24
• Media Type: D
• Archive: Yes

Spillway structures installed, and none are required
Impoundment Factor of Safety
A factor of safety calculation for the embankment on the south end of Pond 015 is unnecessary
for the following reasons:
1. Pond 015 is excavated entirely from sandstone bedrock.
2. The entire pond is incised in bedrock; there is no constructed dam.
3. The steepest slope in Pond 015 is 1 H:1 V, and is an internal slope. No external slope is less
than 2H:1 V.
4. The bedrock material is competent sandstone. A Cat D11 dozer with a ripper was required
to break out pieces of bedrock to be removed via loader and truck.
5. There is only 1.5 feet of soil on top of the embankment. This is the only consolidated
material in the embankment.
As can be seen in the following image, the excavation of Pond 015 is out of competent bedrock.
Therefore, analyses like the Bishop's Method of Slices are inapplicable (these methods are for
slopes of unconsolidated material).
(June 2011 TR -60) Attachment 2.05.3(3) -24 -2