2013-08-30_PERMIT FILE - M2012052

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Owner Information Providence Mine Providence Mining, LLC 100 Bennett Avenue Cripple Creek, Colorado 80813 Phone: 719 - 689 -2605 ENGINEER'S CERTIFICATION This report was prepared by t ngineer who's signature appears below or the engineer's direct sup ZlOwz- No. SIGNATURE: 22601 }/(y DATE: ✓ �� 9875 9870 9865 9860 9855 9850 9845 Secondary Storage Depth (11 Primary Storage ' _modS /// / IN///// / / / / / 9870 9865 9860 SECTION A — ACROSS DUMP TOP AND STORMWATER STORAGE AREA in nonlaminar flow TION B — ACROSS UPPER ROAD AND RUN —ON DIVERSION 0.016 0.014 Total Surface Flow in Channel at Office - (Section B) 0.012 0.018 0.010 9.3 ACRES 0.000 HISTORICAL DISTURBANCE- 3 ACRES NEW DISTURBANCE- LESS THAN 0.25 ACRES O.00fi UNDISTURBED AREAS 42 DISTURBED AREAS 60 CONCRETE-ROOF 100 O.00q Noie: gun- oRwithin disturbe high followed bya decline curve a reas lncreazesonces °Its have 0.000 DIA. HISTORIC MNING HAS DISTURBED THE SURFACE IN THE AREA WITH 5 10 35 20 26 STRUCTURES,AND ROADS. DESCRIPTION OF NONDISTURBEDVEGEFATION AREAS GRASSES AND SHRUBS, WITH SCATTERED TREES. POTENTIAL POLLUTION SOURCES TO STORMWATIER ORE (SOMETIME IN FUTURE), FUEL AND LUBRICANTS LOCATION OF NON�STORMWATER DISCHARGE NO SOURCES KNOWN NAMEAND LOCATION OF RECEIVING WATERS t CRIPPLE CREEK, AN INTERMITTENT STREAM LOCATED 3,500 FEET DISTANT TO THE SOUTHWEST. RESULTS OF CALCULATIONS MAXIMUM SURFACE FLOWS -2 -HR 100 -YR EVENT WASUREDAT STORIWATER DIVERSION CONTROL POINT NEAR OFFICE —Total Flawat Offee 1.1 ACRES (GRASS) RUN-ON EXCLUSION FROM DISTURBEDAREA (HISTORIC 0.12ACRES MAXIMUM FLOW AND VELOCITY IN DIVERSION CHANNEL Q = 0.02 CPS V =LESS THAN 3.9 FPS GRADE= 4% d a rea exlnbin typical meal NEW PRECIPITATION WATER GENERATED BY OPERATION 2.48 INCHES PRECIPITATION PRODUCES 444 CU FT FOR 10 -YEAR EVENT whereas flow ongrassy (BUILDINGS AND CONCRETE SURFACES ASSOC WITH become saturated. CURRENT OPERATION- 2150 SO FT TOTAL) VOLUME GENERATED ON OLD DUMP SURFACE OLD AREA - 12,000 SO FT 2.48 INCHES OF RAINFALL (170 CU FT) DISTURBANCE (CURRENT WORK AREA) (CN = 60) TOTAL CALCULATED STORMWATER GENERATED WITHIN 615 CU FT (SUM OF BUILDING RUNOFF PLUS HISTORIC GROUND SURFACE) CURRENT WORK AREA (10- YEAR STORM) PRIMARY STORAGEAREA CAPACITY 2050 CU FT AT DEPTH OF 9 W 0.002 12, 000 CUBIC FEET AT A DEPTH OF 1 FT (BOTH FOR 10 -YEAR EV ENT) OUTER BERM Hr7GHT OF 1.5 FEET ALLOWS FREE BOARD OF GREATER THAN 0.5 True (hours) FEET. CAPACITY OF SECONDARY STORAGEAREA PROVIDES FACTOR OF 0.016 0.014 PROVIDENCE MINE, TELLER COUNTY, COLORADO 0.012 UNDERGROUND MINE 0.010 9.3 ACRES 0.000 HISTORICAL DISTURBANCE- 3 ACRES NEW DISTURBANCE- LESS THAN 0.25 ACRES O.00fi UNDISTURBED AREAS 42 DISTURBED AREAS 60 CONCRETE-ROOF 100 O.00q Noie: gun- oRwithin disturbe high followed bya decline curve a reas lncreazesonces °Its have 0.000 DIA. HISTORIC MNING HAS DISTURBED THE SURFACE IN THE AREA WITH 5 10 35 20 26 FLOW CURVE tl — CALCULATED FLOW VOLUME OF CHANNEL FOR UP— GRADIENT DIVERSION — USCS METHOI ENGINEERING AND DESIGN NOTES: SITE DESCRIPTION PROVIDENCE MINE, TELLER COUNTY, COLORADO ACTIVITY UNDERGROUND MINE TOTAL MINE PERMT AREA 9.3 ACRES TOTAL DISTURBED AREA HISTORICAL DISTURBANCE- 3 ACRES NEW DISTURBANCE- LESS THAN 0.25 ACRES SCS RUNOFF CURVE VALUES(CN) UNDISTURBED AREAS 42 DISTURBED AREAS 60 CONCRETE-ROOF 100 DISCRIPION OF DISTURBED AREAS ROAD SURFACE CONSISTS OF POORLY GRADED MXTURE OF ROCK UPTO 31N DIA. HISTORIC MNING HAS DISTURBED THE SURFACE IN THE AREA WITH DISTURBANCES INCLUDING WASTE ROCK PILES, LEVELED AREAS FOR STRUCTURES,AND ROADS. DESCRIPTION OF NONDISTURBEDVEGEFATION AREAS GRASSES AND SHRUBS, WITH SCATTERED TREES. POTENTIAL POLLUTION SOURCES TO STORMWATIER ORE (SOMETIME IN FUTURE), FUEL AND LUBRICANTS LOCATION OF NON�STORMWATER DISCHARGE NO SOURCES KNOWN NAMEAND LOCATION OF RECEIVING WATERS DISCHARGE TO NORTH- TRENDING UNNANIDGULCH THAT CONNECTS TO CRIPPLE CREEK, AN INTERMITTENT STREAM LOCATED 3,500 FEET DISTANT TO THE SOUTHWEST. RESULTS OF CALCULATIONS MAXIMUM SURFACE FLOWS -2 -HR 100 -YR EVENT WASUREDAT STORIWATER DIVERSION CONTROL POINT NEAR OFFICE RUN-ON EXCLUSION FROM UNDISTURBED AREA 1.1 ACRES (GRASS) RUN-ON EXCLUSION FROM DISTURBEDAREA (HISTORIC 0.12ACRES MAXIMUM FLOW AND VELOCITY IN DIVERSION CHANNEL Q = 0.02 CPS V =LESS THAN 3.9 FPS GRADE= 4% CALCULATED AT OFFICE LOCATION - SECTION B) NEW PRECIPITATION WATER GENERATED BY OPERATION 2.48 INCHES PRECIPITATION PRODUCES 444 CU FT FOR 10 -YEAR EVENT (NEW DISTURBANCE) (CW 100) (BUILDINGS AND CONCRETE SURFACES ASSOC WITH CURRENT OPERATION- 2150 SO FT TOTAL) VOLUME GENERATED ON OLD DUMP SURFACE OLD AREA - 12,000 SO FT 2.48 INCHES OF RAINFALL (170 CU FT) DISTURBANCE (CURRENT WORK AREA) (CN = 60) TOTAL CALCULATED STORMWATER GENERATED WITHIN 615 CU FT (SUM OF BUILDING RUNOFF PLUS HISTORIC GROUND SURFACE) CURRENT WORK AREA (10- YEAR STORM) PRIMARY STORAGEAREA CAPACITY 2050 CU FT AT DEPTH OF 9 W SECONDARY STORAGE CAPACITY(OUTER BEIRM 12, 000 CUBIC FEET AT A DEPTH OF 1 FT (BOTH FOR 10 -YEAR EV ENT) OUTER BERM Hr7GHT OF 1.5 FEET ALLOWS FREE BOARD OF GREATER THAN 0.5 FEET. CAPACITY OF SECONDARY STORAGEAREA PROVIDES FACTOR OF SAFETY OF 25 FOR STORNWATER GENERATED FROM JUST BUILDINGS AND CONCRETE PADS. IT PROVIDES A FACTOR OF SAFETY OF 20, IF HISTORIC DISTURBANCES ARE INCLUDED. DESIGN DETAILS 1. WHILE THE SITE IS STILL IN EXPLORATION STAGE, THE LOCATION OF HVPOTHEIICAL TEM9�RARY ORE STORAGE PAD IS SHOWN AND IS INCLUDED WITHIN THE STORMMVATER CONTAINMENT AREA. THE STORNMIATER CONTAINMENT AREA CONSISTS OF A PRIMARY AREA LOCATED ON THE DUMP, ALONG WITH A SECONDARY CONTAINMENT WITHIN THE A 1.5 -FOOT HIGH SOIL BERM(, DESIGNED TO CONTAIN ALL WATER FROM WORKING AREA, THE DESIGN EXCEEDS REGULATORY REQUIREMENTS FOR VOLUME RETENTION. 2. WE TO THE SMALL SIZE OF THE ST! I- ONLY ONE DESIGNED DIVERSION IS NECESSARY. THIS DIVERSION WILL DIVERT UP- GRADIENT WATER AWAY FROM THE DUMP WORKING AREA ALONG THE NORTH ACCESS ROAD. SEDIMENT RETENTION WILL BE GAINED ALONG THE ACCESS ROAD WHERE THE SLOPE OF ITS SURFACE DECREASES. NO RETENTION FONDS, LINED OR UNLINED CHANNELS, RUN-ON AND RUN- OFF CONTROLS, OR OUTLET CHANNELS ARE NECESSARY FO THIS SITE AS COLLECTED SURFACE WATERS ASSOCIATED WITH THE NEW DISTURBANCE WITHIN THE WORK AREA CAN BE DISSIPATED VA INFILTRATION. UPPER DIVERSION ON SOUTH IS CURRENTLY SUFFICIENT FOR THEAN ICIPATED SURFACE WATER FLOWS AND ADDITIONAL CONSTRUCTION UPGRADE WOULD UN- NECESSARILY INCREASE DISTUBANCE FOOTPRINT. 3. PERMANENT OR TEMPORARY SOIL STABILIZATION MEASURES SHALL BE APPLIED TO NEWLY DISTURBED AREAS NO LONGER IN USE WITHIN 30- DAYS AFTER USE HAS CEASED IT IS RECOMMENDED THAT ANY PERMANENT SEED MIX BE APPLIED NO EARLIER THAN NOVBvER TO KEEP SEED FROM GERMINATING UNTIL SPRING. AN APPROVED SEED MM SHALL BE APPLIED AT RATES RECOMMENDED BY THE ENGINEER AND SEED VENDORS. 4 SEDIMENT TRENCHES ARE LOCATED DONMGRADIENT OF THE DUMP AND WORK SURFACE AND HAVE BEEN INSTALLED ASA SAFETY BACKUP FOR SEDIMENT CONTROL THE DESIGN DEPTH OF THE TRENCH IS 1.5 -FEET. TRENCHES, AS ALL OTHER CONTROLS, ARE TO BE MAINTAINED DURING THE LIFE OF THE PROJECT. 5. AREAS WHERE FINE GRAINED SOILS ARE SUBJECT TO EROSION SHALL BE PROTECTED USING SILT FENCE PLANTEDGRASSES, Cl MULCH, OR OTHER SUITABLE MEANS.