C 0 REV. NO. DATE OF ISSUE OUAL ITV PLAN QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404-405 FOR REMEDIAL ACTIVITIES FOR TAILINGS PILES FOR UMETCO MINERALS CORPORATION URAVAN MILL URAVAN, COLORADO PREPARED BY CHEN ANO ASSOCIATES, INC. DENVER, COLORADO PURPOSE OF ISSUE ISSUE APPROVED BY 0 6/12/87 For Submittal to State 1 2/10/88 For Construction ~!~!• Approval j.¾7& t/ S" ~ - '-
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REV. NO. DATE OF ISSUE
OUAL ITV PLAN
QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404-405
FOR
REMEDIAL ACTIVITIES
FOR
TAILINGS PILES
FOR
UMETCO MINERALS CORPORATION URAVAN MILL
URAVAN, COLORADO
PREPARED BY CHEN ANO ASSOCIATES, INC.
DENVER, COLORADO
PURPOSE OF ISSUE ISSUE APPROVED BY
0 6/12/87 For Submittal to State 1 2/10/88 For Construction
~!~!• Approval j.¾7& t/ S" ~ -'-
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QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404, 405
INDEX
Page No.
PART I GENERAL
1.0 SCOPE OF QUALITY PLAN. . . . . . . . . . . . . 2.0 LIST OF QUALITY CONTROL PROCEDURES . • . . . . . . . . 3.0
of the Tailings Piles will also be taken after completion of the
reclamation cover and drainage channels. Additional aerial
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QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404, 405 PART III
Page 30
photographs will be required only if the visual inspection indicates
such a necessity.
2.s Environmental control Procedures
Environmental control Procedures E2.l, Tailings seepage con
trol, and E-4.5, Tailings Stability Monitoring, give additional
details and Quality Control/Quality Assurance for monitoring the
Tailings Piles.
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3.0 SURFACE RUNOFF CONTROL FACILITIES
QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404, 405 PART III
Page 31
In conjunction with observation of the surface monuments and
reclamation cover, the runoff collection and diversion channels will
be observed for evidence of erosion or debris and sediment accumula
tion. These observations will be made at the same time as the moni
toring of the erosion monuments.
Environmental Control Procedure E-3.4 Ditch Diversion
Inspection shall be followed.
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PART IV PERFORMANCE EVALUATION
QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404, 405 PART IV
Page 32
l.O SCOPE OF PERFORMANCE EVALUATION
Performance of the Remedial Activities shall be evaluated to
assure long-term Tailings Pile stability, cover integrity, and the
decline of seepage over time. Monitoring of the following instru-
mentation installed in accordance with the Specifications will be
used as to generate data for the performance evaluation. The tail
ings Piles monitoring systems consist of the following:
(1) Piezometers
(2) surface Movement Monuments
(3) Erosion Monuments
(4) Visual Inspections and Aerial Photography
0 2.0 PIEZOMETERS
QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404, 405 PART IV
Page 33
The piezometers will monitor the change in fluid levels in the
piles at the crest of the rockfill buttress, on the embankment face,
and on the retirement crest.
Data collected from the piezometers will be used to aid in
estimating Tailings Pile settlement (consolidation) and in determin
ing when the toe drain system can be abandoned. Additionally, the
monitoring of the piezometers should be used to determine if the
Remedial Plan is operating as proposed. When all necessary informa
tion has been obtained, the piezometers will be properly plugged
with a bentonite slurry.
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3.0 SURFACE MOVEMENT MONUMENTS
QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404, 405 PART IV
Page 34
The surface Movement Monuments will be used to establish the
post-remediation settlement, erosion, and to determine the amount of
movement of the embankments.
Data collected from the Surface Movement Monuments will be used
to determine the integrity and effectiveness of the reclamation
cover by ascertaining the amount of settlement, erosion, and embank
ment movement.
4.0 EROSION MONUMENTS
QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404, 405 PART IV
Page 35
The Erosion Monuments will be used to determine the amount and
rate of gully erosion and cliff retreat in the Tailings Piles Area.
These monuments will be surveyed and their location described.
Additionally, the proximity to the cliff edge and other pertinent
observations will be described and recorded. The monuments will be
observed visually and surveyed, if necessary, during the long-term
monitoring program. From these observations, the rate of cliff
retreat will be determined and potential impact on the integrity of
the disposal area assessed.
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QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404, 405 PART IV
Page 36
5.0 VISUAL INSPECTION AND AERIAL PHOTOGRAPHY
Visual inspection and aerial photographs shall be used as re
quired to aid the Performance Evaluation.
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6.0 PERFORMANCE OF RECLAMATION COVER
QUALITY PLAN NO. QP-404-1 PROJECT NOS. 404, 405 PART IV
Page 37
All monitoring data shall be evaluated in the context of design
expectations and performance predictions. The periodic evaluation
shall be comprehensive and shall include discussion of the interre
lationship between the monitoring data and the predicted performance
of the Tailings Piles with respect to short and long term pile sta
bility, cover integrity, load/settlement, dewatering and seepage.
Based on a comprehensive assessment, "action" and "concern" levels
shall be specified and discussed in each evaluation. "Concern"
level shall mean that monitoring data is reflecting Tailings Pile
performance which is grossly inconsistent with expectations and may
lead to environmental damage. "Action" level means action must be
taken immediately to mitigate the problem reflected by the monitor
ing·data. contingencies shall be included in this evaluation where
appropriate.
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New Repository Quality Plan Appendix A to Quality Plan QP-404-1
Part I - GENERAL
1.0 Compliance Reports
QUALITY PLAN NO. QP-404-J REPOSITORY CONSTRUCTION
APPENDIX A
Compliance Reports shall be prepared by the Quality Control Officer for written approval by the Site Manager and the ON-Site Coordinator (OSC) where noted in the following sections. Compliance Reports shall be prepared for the following:
Report No.
CR-404-8
CR-404-9
CR-404-10
CR-404-11
CR-404-12
Work Items
Preparatory Work
Placement of Contaminated Materials on the Repository
Reclamation Cover for 5H:1V Slopes and Top of Repository
Repository Surface Run~ff Control Facilities
Rep~sitory Monitoring Devi~es . . . . .
Part II - QUALITY CONTROL/QUALITY ASSURANCE
1.0 Preparatory Work
1.1 Removal of Existing Riprap Cover Materials
Toe QC Officer shall verify the following:
(1)
(2)
(3)
Existing riprap m~terials are radiologically scanned during removal from the rockfill buttresses and Tailings Piles to verify suitability for re-use. Unsuitable materials are placed within the repository.
Existing riprap materials are removed from the rockfill buttresses and Tailings Piles to expose the specified underlying material. Observe and approve proof rolling of exposed rockfill material and visually verify that rockfill material consists of a granular, 12 inch minus material.
Suitable riprap materials are sorted, graded and stockpiled by Type for re-use.
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(4)
1.2
QUALITY PLAN NO. QP-404-1 REPOSITORY CONSTRUCTION
APPENDIX A The compacted random fill and clay fill lining materials are placed on the exposed surface of the rockfill buttresses in accordance with the Specifications and as shown on the Drawings following the Quality Control given in Part II, Section 3.0 of this Quality Plan.
Redundant Toe Drain Installation
The QC Officer shall verify the following:
(1) Drain systems are constructed at the locations and to the construction details shown on Drawing P-404-11 after removal of riprap cover materials from the existing tailings piles.
(2) The drain dimensions are checked for conformance with the Specifications. Documentation of the measurements and surveys shall be reviewed by the QC Officer. Approval of the construction shall be documented in writing by the QC officer.
(3) The compacted random fill and clay fill linings above the drain are installed in accordance with the Specifications by following the Quality Control given in Part II, Section 3.0 of this Quality Plan.
(4) Placement of the drainage material shall be monitored to ensure the following requirements are being met:
a) The correct type of material with the specified gradation is being used.
b) The material being placed is clean and free of unsuitable material.
c) The material is being loaded, transported and placed in a manner which minimizes segregation.
d) The material is being placed to the lines and grades designated in the Specifications and on the Drawings.
e) The pipe is installed with the perforations downward and pipe segments are joined in accordance with the manufacturer's recommendations.
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1.3
(I)
(2)
1.4
1.4.l
(1)
Starter Berm Construction
The QC Officer shall verify the following:
QUALITY PLAN NO. QP-404-1 REPOSITORY CONSTRUCTION
APPENDIX A
The starter berm(s) are constructed at the locations and to the construction details shown on Drawing P-404-11. If modifications to the berm alignments are required by site conditions, such re-alignment shall be approved by the Site Manager or his designated representative, with the agreement of the OSC.
The compacted random fill and clay fill materials are installed in accordance with the Specifications by following the Quality Control reguirements given in Part II, Section 5.0 Earthwork.
Return Water Pond
Preparation of Pond Embankment
The QC Officer shall verify the following:
The new Return Water Pond is constructed at the location and to the construction details shown on Drawing P-404-11. If modifications to the berm alignments are required by site conditions, such re-alignment shall be approved by the Site Manager or his designated representative, with the agreement of the OSC.
(2) The compacted random fill and clay fill materials and the leak detection system are installed in accordance with the Specifications by following the Quality Control given in Part II, Section 5.0 Earthwork and Quality Plan OP-401-1 where relevant to leak detection system installation.
1.4.2 Synthetic Liner Material
The QC Officer shall verify the following:
(1) The synthetic liners are manufactured of new, first quality products designed and manufactured specifically for the purpose of liquid containment. The QC Officer shall visually docwnent that the materials are new.
(2) The liner materials are free of holes, blisters, undispersed raw materials or contamination by foreign matter. Any such defect shall be repaired using the extrudate welding technique in accordance with the manufacturer's recommendations.
(3) Certification from the Liner Manufacturer documenting that the liner meets all physical property specifications for the intended application has been received and approved.
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QUALITY PLAN NO. QP-404-1 REPOSITORY CONSTRUCTION
APPENDIX A 1.4.3 Field Seams
(I)
(2)
(3)
(4)
2.0
(1)
The QC Officer shall verify the following:
The integrity of the field seam is determined in accordance with Quality Control Procedure QC-19.
The location of the seams, the machine used, the operator, weather conditions and any problems are logged on a daily basis.
Vacuum Box Testing - All field seams are inspected for unbonded areas by applying a vacuum to a soaped section of seam. This nondestructive test is performed in accordance with Quality Control Procedure QC-19. Repairs - All defective field seams as detected by both destructive and nondestructive tests are marked and repaired in accordance with manufacturer's recommendations.
Placement of Contaminated Materials on the Repository
The QC Officer shall verify the following:
Only materials designated for placement on the repository are placed on the repository.
(2) Size of scrap placed on the repository has a maximum dimension of 10 feet and a maximum volume of 30 cubic feet.
(3) Scrap having a hollow volume of greater than 5 cubic feet is reduced in volume by at least 70 percent prior to placement on the repository.
(4) Scrap is spread across the repository to avoid nesting and to reduce the volume of voids. No scrap is placed in the first two (2) foot lift or layer of contaminated material.
(5) Tailings, neutralized sludge, soils and/or any other designated waste forms are placed over and into the scrap in sufficient amount to fill the voids between the large pieces and the volume within the hollow pieces, recognizing that some voids will remain as provided for in the Specifications.
(6) The first layer of tailings, neutralized sludge, soil and/or any other designated waste forms does not exceed 2 feet in thickness. Subsequent layers do not exceed 2 feet in thickness except for isolated scrap protrusions.
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(7)
QUALITY PLAN NO. QP-404- J REPOSITORY CONSTRUCTION
APPENDIX A Tailings, neutralized sludge, soils and/or any other designated waste forms are compacted to at least 90 percent of Standard Proctor Maximum Density at a moisture content no greater than optimum.
(8) The contaminated materials are placed to contain drainage on top of the repository at all times and where possible, the working surface is sloped toward the back of the repository at a minimum slope of J percent.
(9) The contaminated materials are placed to achieve the final repository configuration with S(H): I (V) slopes and the top of the repository is sloped toward the crest at 3 percent as shown on Drawing P-404-8.
(I 0) The frequency of the Quality Control Tests shall be in accordance with the Specification for contaminated material placement.
3.0 Reclamation Cover for S(H):l<Y} Slopes and Top
The QC Officer shall verify the following:
(l) The reclamation cover is constructed in accordance with the Specifications including Drawings P-404-8, P-404-9 and P-404-10.
(2)
(3)
(4)
(5)
(6)
The clay soiVradon barrier is placed over the contaminated material on the 5(H):l(V) slopes and over the contaminated materials on top of the repository. The clay soil material shall meet the requirements of Specification P-404-1. Part VII. Section 5.0. Article 5.1 for radon barrier/clay fill be in accordance with the specified and shall be removed from an approved Borrow Source.
The clay soil/radon barrier is placed in horizontal compacted lifts not to exceed 6 inches in thickness and compacted to at least 95 percent of Standard Proctor Maximum Density at a moisture content between optimum and 4 percent over optimum.
The clay soiV radon barrier cover is a minimum of 18 inches thick or as otherwise specified.
Following a seasonal shutdown or period of prolonged exposure to inclement weather or freezing temperatures. the last lift of clay material previously placed and accepted is visually examined and tested in accordance with Specification _ S-404-1, Part VII. Section 5.0, Article 5.1.3
Random filVfrost barrier material is comprised of inorganic soils having a Unified Soils Classification System classification of CL and/or CH, maximum size of .2. inches and is removed from an approved Borrow Source and placed in a cover layer over the clay soil radon barrier.
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QUALITY PLAN NO. QP-404-1 REPOSITORY CONSTRUCTION
APPENDIX A (7) The random fill/frost barrier material is placed in horizontal compacted lifts not
exceeding 1 foot in thickness and compacted to at least 95 percent of the Standard Proctor Maximum Density at a moisture content above minus 2 percent of optimum.
(8) The random fill frost barrier is at least 4.5 feet thick or as otherwise specified.
(9) Riprap excavated from the Burbank Quarry or other approved Borrow Source or stockpile having a gradation as specified on the revised project Drawings is placed over the random fill frost barrier.
(10) The riprap is placed in a single lift in such a manner so as to minimize segregation and receives at least two passes of a D-7 Dozer or equivalent.
{11) Accumulation ofriprap sizes less than the minimum DS0 size is removed and blended with subsequently delivered loads to meet the desired gradation.
(12) The riprap layer is at least I foot thick.
(13) The frequency of Quality Control Tests shall be in accordance with the Specifications for reclamation cover construction.
4.0 Surface Runoff Control Facilities
The QC Officer shall verify the following:
(1) The exposed rockfill buttresses and Tailings Pile surfaces are regraded during repository construction as necessary to prevent gullies from forming.
(2) Drainage on top of the contaminated material on the repository is maintained by providing a minimum 1 percent slope towards the back of the repository.
(3) Following precipitation events, collected runoff is continuously pumped from the top surface of the repository so that the water is drawn down as soon as is practicable. Under no circumstance will collected water be allowed to pond on the top surface of the repository for more than 10 days after stonn events.
(4) Pennanent Groin Channels TP2 and TP3 and diversion ditches B-1 and B-2 are constructed at the locations and to the lines and grades shown on Drawings P-404-8 and P-404-10.
(5) Permanent Channels and ditches are lined with the specified Type of riprap where excavated or constructed in soils in accordance with the Specifications.
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6.0 Monitoring Devices
QUALITY PLAN NO. QP-404-I REPOSITORY CONSTRUCTION
APPENDIXA
Monitoring devices shall be installed in and/or modified adjacent to the repository to monitor the performance of the repository or existing Tailings Piles as appropriate during and after construction. The QC Officer shall verify the following:
(I) Existing piezometers presently located on Tailings Piles 2 and 3 are extended as necessary and maintained utilizing similar materials as shown on Drawing P-404-7.
(2) New piezometers are installed as shown on Drawing P-404-7 at locations to be determined in the field. The location of new piezometers are shown on the "AsBuilt" Drawings
(3) Surface movement monuments are installed as shown on Drawing P-404-7 at locations to be determined in the field during repository construction. The location of movement monuments are shown on the "As- Built" Drawings.
The QC Officer shall ensure that monitoring devices are installed in accordance with the Specifications through periodic inspection of the construction.