2008-10-17_PERMIT FILE - M2008017 (4)

Home Browse Search

3 a I ' � 1y X I X11 \ I I I I` S � X1 I ~ I I 11 r l 1J � Tie I\ 3 UA Z I . a \ I \ I I \ I 11 X I I I I I II � III X 1 I I I h I 1 1 I I X) � � II I I I x II � I pl l �II VARIES �} w- W a_ � a- -i Uo N -i KW J Q a_ a w 3 25' \< < \ \ , , ��. 1 0 0 z Z J OVERBURDEN AND TOPSOIL BACKFILL ALL DISTURBED AREAS DOWN TO WATER SURFACE N.T.S. BACKFILL EXISTING TRENCH WITH NATIVE MATERIALS 3' -5 VARIES ASTM C33 -7 CONCRETE AGGREGATE . ASTM C33 CONCRETE SAND (IF REQUIRED) 1.5' TYP. " a ° < 2' ° : (MIN) ; ° d G VARIES a 4.0' a. : 4 . ° ° .05 1.5 °(TYP.� ° (TYP.) TY 4. 3' 4' F N.T.S. 1 � 1 \ \ \ \ 1 1 \ _ LEGEND: A UTILITY POLE GUY WIRE G 4 GAS LINE MARKER • GAS VALVE ® WELL OO WATER METER X WATER FAUCET w WATER LINE MARKER A ELECTRIC TRANSFORMER 0 TREE El TELEPHONE PEDESTAL T TELEPHONE LINE MARKER PROPERTY LINE FENCE LINE — of oe OVERHEAD XCEL POWER LINE G EXISTING DCP MIDSTREAM GAS LINE .. ` NORTH WELD WATER DISTRICT WATER LINE -- — - — EXISTING CONTOURS (2' INTERVALS) GRAVEL ROAD PROPOSED PERMIT BOUNDARY PROPOSED SLURRY WALL 46 PROPOSED CONTOURS PERIMETER DRAIN WATER SURFACE ` \ \\ \ L i 100 50 0 100 200 300 SCALE IN FEET NOTE: ALL DISTURBED AREAS OUTSIDE OF WATER SURFACE WILL BE SEEDED AND MULCHED WITH THE EXCEPTION OF ACCESS ROADS WHICH WILL BE GRAVEL SURFACED. NN r \ SANDY CLAY OVERBURDEN SAND AND GRAVEL ALLUVIUM SLURRY WALL NOTES: I. Bentonite Specifications YP /PV ratio API Std. 13A less than 3 Viscometer greater than 30 Filtrate Loss less than 15 cm3 Moisture Content ASTM D 2216 less than 10 percent Test results for each lot of bentonite must be provided. 2. Water S12ecifications pH 6 -8 Hardness less than 200 pprr Total Dissolved Solids less than 500ppm Oil, organics, acids, alkali less than 50 ppm each Chloride report 3. Bentonite Slurry General Specifications The initial bentonite slurry must be tested prior to placement in the trench. The slurry may be mi:xed in high shear mixers or mixed and hydrated in slurry hydration ponds. In general, a minimum hydration time of 8 hovers will allow the bentonite slurry to meet all criteria. A minimum bentonite content of 6 percent in the slurry by weight is required. 4. Bentonite Slurry Testing Specificatirons before Placement Viscosity Measured w/ Marsh Funnel (API RP 138 -1) less than 40 sec Density less than 64 pcf Filtrate Loss less than 20 cm3; pH 6.5 to 10 The tests listed above should be run 1 or 2 times per shift and at least once per batch of slurry. The slurry must be further tested after placement in the trench. The tests conducted are for viscosity, density, sand content, and pH. Two sets of tests per shift at two locations in the trench (approximately 2 feet below the slurry surface and 2 feet above the bottom of the trench) are required. If the density of the slurry in the trench exceeds 85 pcf the excess solids must be removed by desonding or the slurry replaced with fresh slurry. The slurry level must be maintained at least 3 feet above the ground water elevation and no more than 2 feet below the top of the workinq vlotform- _L", Unit Weight 1.03 to 1.40 gm /cm3 Sand Content ASTM D 4381- 84(1993)e10 to 20 percent by volume 6. Soil — Bentonite Bo .kfill So cifi ations S —B backfill slump ASTM C 143 1 set per 100 cu. yds. Slump 2 -6 inches S —B backfill gradation 1 set per 300 cu. yds. Screen (US Standard) Percent by Dry Weight 3 inch 100 # 4 40 -80 # 25 -60 #200 20 -40 Minimum Plasticity Index of 10 7. Kev Trench and Slurry Wall C'ao Spe ifi ations During excavation, soundings should be obtained to determine the elevations of the top of the key layer, the bottom of the excavation, and the bottom of the trench prior to backfilling. If sediments in excess of 2 inches have accumulated it is necessary to clean the trench bottom by airlift pumps or excavation equipment to remove the sand and sediment that has settled. The trench bottom should be cleaned, as a minimum, at the beginning of each shift. Soundings should be obtained approximately every 20 feet. Adequate keying in the S —B backfill to an impermeable layer at the base of the wall will be required and specified in the final design report for the slurry wall. The design documents will include a description of the key in layer and describe how trench cuttings or other observations will be used to assure that the slurry wall will be adequately keyed. Temporary slurry wall protection will be required in the form of a noncompacted soil cover placed within one day over each backfilled 100 foot reach. The temporary cover is removed after settlement (approximately 2 weeks) and replaced with a compacted clay cover over the completed slurry wall. 8. Post Constr , tion T sting Post construction testing will be conducted in accordance with the "Colorado State Engineer's Office." 9. Above specifications (notes 1 -8) are provided as a general guideline for permitting purposes. Final specifications and design criteria will be developed during the fin desiqn of the sl wall taM y r � W a Z X W 0 J J E d H Z d � 3 � i Q � i m C 0 a U o I Z O W t } U � T L7 m � 3 0 � m ^ o � 0 0 z N M o U) c14 M N Co o t' �O"'F 0 U - Q c LO o -p u1 M C .0 p c L u, Ln 333 ` M C o O M � d 0_ W 0 E U N Job a #- 0 7123 Date 217/0 Dra BY — -- wS S �� 8 TPY Checked By JCY File _ JT_Redamation Sheet: 1" = 100L EMMEEMMM� Of: 1 ,