Surface Water and Groundwater Hydrology
Projects
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Surface Water and Groundwater Assessments
Western Colorado
Surface water and groundwater are the primary media of
concern evaluated in relation to the more than 20 inactive and
abandoned mine lands assessments performed by Western Water &
Land personnel throughout western Colorado. The evaluations
typically involve measurement of flow rates in area streams and
springs and collection of water samples from streams, drainages,
and springs for laboratory analysis. Analytical results are
used to perform streamlined risk evaluations whereby the data
are evaluated against established stream standards, risk-based
benchmarks established by the US EPA and the State of Colorado,
and risk management criteria established by the US BLM for mine
sites.
Surface Water and Groundwater
Assessment
Eastern Utah
Assessment of surface water and groundwater resources
was a primary component of the La Sal Creek Watershed Project
conducted to evaluate impacts resulting from former operation of
five uranium mines in eastern Utah. The project was conducted
under the direction of the US BLM with US EPA oversight. The
mines are located along the Colorado/Utah state line and are
upgradient of La Sal Creek and several major tributaries which
are used for recreational purposes and as an irrigation source
by local residents. In addition, local residents in the
vicinity of the mines rely on wells and nearby springs for their
domestic water needs. Water draining from the mines and runoff
waters infiltrating the waste-rock dumps are considered primary
contaminant source areas of concern, potentially contributing to
degradation of La Sal Creek and groundwater resources in the
area.
Data were gathered for the study by measuring discharge rates in
area streams and collecting water samples in nearby reference
areas to assess natural background conditions, from area springs
and seeps, mine drainage channels, La Sal Creek and its major
tributaries, and at each of the local residences. In addition,
a benthic macroinvertebrate survey was conducted along La Sal
Creek and its tributaries, co-located sediment samples were
collected at each surface-water monitoring station, pasture
grass samples were collected from irrigated fields, and samples
of produce were collected from residential gardens and fruit
trees.
The samples were submitted to an analytical laboratory for
analysis of a comprehensive list of metals, inorganics, and
radionuclides. Sample results were compared to natural
background levels reported for the reference area samples and a
streamlined risk evaluation was performed to assess potential
threats to human health and the environment. The streamlined
risk evaluation utilized risk-based benchmarks established by
the US EPA, State of Colorado, and State of Utah and risk
management criteria established by the US BLM for mine sites.
Results of the evaluation were used to prepare an engineering
evaluation/cost analysis document in accordance with removal
action requirements set for in the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA).
Colorado River Water Quality
Evaluation
Western Colorado
Western Water & Land was selected to participate on a
team of professionals assembled by the Colorado River Water
Conservation District to evaluate the impacts associated with
various water management options being considered for the
Colorado River Basin. Western Water & Land was selected for the
team based on the firm’s technical expertise and strong
reputation in western Colorado. The objective of the options
being considered is to increase eastern Colorado supplies
without negatively impacting the interests of western Colorado
water users.
The proposed options include pumpback scenarios from Green
Mountain Reservoir to Dillon Reservoir coupled with diversions
to and releases from a new reservoir to be constructed within
the Eagle River Basin. Western Water & Land is responsible for
evaluation of impacts to water-quality conditions along the
Eagle and Colorado Rivers. The work was initiated by
identifying the water quality issues of concern based on
discussions with western Colorado water user organizations and
water attorneys. The identified issues were examined to develop
a list of water-quality parameters to be evaluated during the
study.
Historical flow and water-quality data were compiled and used to
assess relationships among the target parameters and develop an
understanding of baseline conditions during typical, wet, and
dry years. The identified relationships among the parameters,
predicted water quality conditions within the new reservoir, and
mass-balance analyses were used to predict how water-quality
conditions at specific locations along the rivers would likely
respond to the proposed operational changes in the system.
Evaluations results will be reported to technical and management
committees consisting of individuals representing Colorado River
water interest. Findings of the study will be used by the
committees to make informed decisions regarding implementation
of the proposed options.
Numerical Groundwater Modeling
Tuba City, Arizona
Western Water & Land developed and constructed a
numerical groundwater model for over 65 square miles of terrain
near Tuba City, Arizona. The work was conducted for MACTEC-ERS,
the prime contractor for the U.S. Department of Energy Grand
Junction Projects Office. The project involved the development
of a local-scale model (Phase II) from a previously completed
site-scale model (Phase I). The purpose of the project was to
develop a steady-state local-scale model that would be used to
evaluate the affect of hydrologic stresses associated with
remediation of the Tuba City UMTRA Site on surrounding area
wells and hydrologic features, as well as the affect of
surrounding stresses in the UMTRA Site.
The Tuba City UMTRA Site is a uranium mill tailings repository
that has developed a groundwater contaminant plume as a result
of transient drainage from the tailings repository. The scope
of work included compilation of all relevant hydrological data
(well and pumping records, precipitation data, and stream and
spring flow data, etc), development of the model domain and
hydrologic conceptual model and water balance, construction of
the numerical model, implementation of model calibration and
sensitivity analysis, and project report preparation.
Groundwater Vistas™ was used as the graphic user interface, and
MODFLOW was used as the model computer. It is anticipated that
future modeling work will include the development of a transient
model and may include contaminant transport modeling.
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Mining
Projects |
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Logan
Wash Mine
Western Water & Land, Inc. (WWL) has been providing engineering
and environmental consulting services in support of reclamation
and closure of the Logan Wash Mine since 1999. The original
mine permit approved approximately 134.7 acres for disturbance
within the permit area with an actual disturbance of 113.6
acres. The major mine facilities consist of a 9 mile access
road, the Research Mine Bench, Dump, and Portal the Upper Bench
and several Upper Portals, the Lower Bench and Portal, the Upper
and Lower Bench Roads, the Upper and Lower dumps, ventilation
shafts, monitoring wells, NPDES outfalls, the Retort Mine Water
Pipeline, and Evaporation Pond. Miscellaneous access roads
exist as well as formerly used mine support facilities.
The initial permit for the Logan Wash Mine was approved in the
mid 1970’s. From 1999 to the present, WWL personnel managed all
maintenance, hydrological investigations, and mine closure
reclamation activities.
Seven technical revisions to the mine permit were prepared and
submitted to DMG for approval. These revisions included an
initial retort closure plan, a passive water treatment study for
the retort mine drainage water, comprehensive design and build
of storm water control structures, portal plug seal design,
Research Mine drainage rerouting, and two reclamation/revegetation
plan revisions. WWL conducted a complete underground
hydrological reconnaissance and sampling of underground wells.
A hydrogeologic conceptual flow model was developed and the
sampling analysis results supported the conclusion that the
modified in situ retorting process at the mine had not
contaminated the aquifer beneath the mine workings. In
addition, WWL implemented mine water management activities that
resulted in a decrease in retort mine water discharge and
periodically stemming flow from the Research Mine. This action
has saved thousands of dollars in sampling and analytical
costs.
Mine
closure activities focused on the management and/or treatment of
retort discharge water. The water is currently being discharged
to an evaporation basin. Alternative retort water treatment
processes included the construction and testing of a passive
bioreactor cell. Final mine closure will result in surface
reclamation of existing roads, portals, benches, and a mine
ventilation structure.
WWL prepared bid documents and oversaw the bidding process for
underground improvement work and removal of highwall structures
on the surface. Underground improvement was conducted to incre ase
mine safety while upgrading all mine drainage structures before
sealing the portals. Other significant projects at the mine
included a 3,000-foot reroute of the Research Mine’s drainage
pipeline; construction of 3 large (800 foot) rip-rap channels to
manage storm water runoff and prevent erosion of dumps and
roads; and the construction of a soil barrow area and importing
of soil from the barrow onto disturbed surfaces. WWL conducted
all the surface reclamation activities at the mine including
shaft and portal sealing, dump-face planting of over 3,000
saplings, preparation and revegetation of benches, roads, and
other related disturbed acreage. In 2006, the Colorado Division
of Minerals and Geology approved warrantee release for 21 acres
at the mine.
WWL is currently conducting mine water and other monitoring
activities at the mine and will conduct reclamation maintenance
and additional reclamation activities as needed depending on
future land use.
In addition to our experience at the Logan Wash Mine, WWL has
extensive experience providing technical services to the oil
shale industry in the Piceance Basin, Colorado. Please contact
us for additional information regarding our experience providing
services to the oil shale industry.
Oil Shale Target Assessments
Utah and Colorado
WWL teamed with a local geologic
services firm to provide several clients with optimal oil shale
mining targets in the Uintah and Piceance (Creek) Basins in Utah
and Colorado, respectively. The assessment was done to support
applications to the U.S. BLM for Research and Development leases
on 160 to 5120 acre tracts on federal lands. The comprehensive
assessment involved an extensive literature research and data
compilation from in-house libraries and USGS libraries. Oil
Shale grade, total thickness of mining units (R-4 through R-8),
outcrop relationships, access, environmental concerns,
overburden thickness, hydrogeology concerns, water resources,
social-economics and private lands issues, and other issues were
addressed in the assessment. Several field reconnaissance trips
were conducted to support the literature research work. The
work resulted in the recommendation of several key oil shale
targets to the clients.
Probable Hydrologic Consequences Refuse Disposal Study
Open Pit Coal Mine, Northern Arizona
Western Water & Land, Inc. was tasked with an in-depth study of
hydrologic impact associated with the disposal of wash-plant
refuse materials at a large open pit coal mine facility. The
work was part of a mine permit renewal effort and included and
initial task of delineating the optimum disposal area at the
mine site followed by a detailed assessment of potential
hydrologic impact. The hydrological assessment addressed
pertinent regulations in 30 CFR 816 as they relate to protection
of the hydrologic balance and disposal of coal mine waste,
potential changes to the hydrologic balance including the
potential for significant acid or toxic infiltration of
groundwater, and changes in present or potential use of
groundwater.
The assessment involved a compilation and interpretation of
hydrogeologic data including, aquifer characteristics
(examination of the potentiometric surface, water quality,
hydraulic parameters, flow directions and gradients), well
construction and core hole data, meteorological data, pit inflow
calculations, surface-water characteristics, mine operation and
engineering data, borehole geophysical data, and spoils
geotechnical data, and other related data. Western Water & Land
submitted a recommendation for the refuse disposal area on the
basis of a thorough evaluation of these data. This work was
followed by an extensive evaluation of the fate and transport of
potential generated leachate from the wash-plant refuse
materials. This evaluation included a statistical assessment of
groundwater quality in the entire mine area as compared to
refuse-generated leachate; groundwater flow calculations;
leachate mixing calculations, and numerical modeling of
saturated and unsaturated groundwater flow and transport. The
final report concluded that the hydrologic impact of
refuse-generated leachate would be of minimal impact to the
aquifers within and immediately underlying the mined area.
Uranium Mill Tailings Repository Conceptual Design
Southeastern Utah
This project involved a uranium mill tailings repository
conceptual design, focusing
on hydrogeologic characterization and groundwater flow and
projected contaminant transport modeling at the repository site
as well as geochemical characterization of leachate from the
existing mill tailings piles to be moved to the repository.
Site hydrogeologic characterization was completed through
compilation and interpretation of site hydrological data,
including detailed geologic and hydrologic evaluation of data
associated with over 80 soil borings, drill holes, and well
completion logs within a one square mile area.
The data indicated the presence of a highly transient and
discontinuous alluvial groundwater system sensitive to annual
recharge as a result of local and region snowmelt. The resulting
complex site conceptual model was translated into a
saturated/unsaturated two-dimensional profile groundwater flow
and transport model. The primary modeling codes used included
HYDRUS (finite difference, one-dimensional) and FEMWATER/FEMWASTE
(finite element, two-dimensional). The FEMWATER/FEMWASTE model
was used to simulate the migration of mill tailings leachate to
the native vadose zone and alluvial groundwater system from an
unlined (no synthetic liner) repository with a vegetated cover.
Geochemical characterization of
leachate was accomplished by designing, installing, and sampling
15 lysimeters constructed within the existing mill tailings
piles. Analytical results for samples from the tailings
lysimeters were used to geochemically characterize mill tailings
leachate at horizons within and below the existing mill tailings
piles.
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Water Resource Planning &
Protection
Projects |
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Watershed Monitoring Program
Mesa County, Colorado
A watershed monitoring program was developed for the
watershed owned by the City of Grand Junction within the Grand
Mesa Slopes area. The program was designed to provide the
technical information needed to ensure protection of source
waters and assist in management decisions regarding source water
fate within the watershed. A watershed monitoring plan was
prepared to administer and guide implementation of the Program.
The plan, developed using the watershed approach, allows for
assessment of baseline conditions and provides a mechanism for
characterization of potential impacts from land development
activities or other future changes within individual watersheds
and sub-watersheds. The plan addresses development of sampling
locations; field procedures for collection of surface water,
groundwater, soil, and sediment samples; analytical program;
quality assurance and quality control; data management; and data
interpretation. Western Water & Land personnel directed the
initial sampling event and trained City personnel on the proper
application of field procedures, quality assurance and quality
control protocols, sample handling, and data management. The
program has been implemented by the City, and Western Water &
Land continues to provide technical direction and oversight on
an as-needed basis.
Watershed Assessment
Mesa County, Colorado
An assessment was
conducted of the Town of Palisade’s watershed located on Grand
Mesa. Western Water & Land personnel inventoried and
characterized springs within the watershed, conducted water
quality sampling, and developed recommendations for potential
spring development. Springs were characterized on the basis of
discharge rate, water quality based on state water quality
standards, and location relative to existing water conveyance
structures. Western Water & Land personnel also assessed an
active landslide area that had impacted water supply development
structures in the watershed, and provided recommendations for
relocation of the structures for the Town.
Watershed Protection
Mesa County, Colorado
A watershed
protection project was implemented to help mitigate the
hydrologic impacts associated with construction of a natural gas
pipeline through watersheds owned/utilized by the City of Grand
Junction and Town of Palisade. The work included field
assessment and coordination of hydrologic issues associated with
proposed pipeline routes; preparation of technical reports and
review of permits associated with watershed access and the
pipeline Plan of Development; and interfacing with
TransColorado’s employees and consultants, as well as various
property owners. This work resulted in pipeline alignment
relocation to avoid sensitive watershed areas, and incorporation
of protective measures for the design of sensitive stream
crossings. Additional work included the design and
implementation of a baseline, surface water-quality sampling
program for geochemical characterization of the watersheds and
an evaluation of compliance with state water-quality
regulations.
Water Supply Alternatives Evaluation and Design
Somerset, Colorado
An aging and failing water supply system was in the need for
replacement at a coal mining facility near the town of Somerset,
Colorado. The mine has historically been responsible for
supplying potable water to the town in addition to potable and
non-potable water for the mine. Water
supply system alternatives were being evaluated for both potable
and non-potable water use. The work involved the evaluation of
overall water man agement at the mine. An assessment of water
rights, augmentation plans, site hydrogeology, future water use,
and current supply system configuration was conducted prior to
compiling potential supply alternatives.
The alternatives assessment involved listing potential likely
supply alternatives. Potential alternatives included
reconstruction of an infiltration gallery accompanied with the
construction of river diversion structures. Each short-listed
alternative was evaluated on the basis of meeting volume goals
and complexity of treatment. Other criteria included permit
needs, timeliness of implementation, and overall cost (capital
and operation and maintenance). Western Water & Land ultimately
recommended a water supply alternative to be followed by system
design, bid documentation, and construction.
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Water Rights & Plans For Augmentation Projects |
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Water Right Applications
Delta, Garfield, Gunnison, Mesa, and Montrose Counties ,
Colorado
Western Water & Land has prepared the technical documentation
required to support numerous applications for water rights,
substitute water supply plans, and plans for augmentation in our
region. We have developed strong working relationships with
prominent local water attorneys, local water commissioners, DWR
state and water division personnel, local irrigation districts
and companies, Colorado River District personnel, and the Bureau
of Reclamation.
Our work has involved surface rights associated with in-stream
flows, runoff, and springs; groundwater rights associated with
new and existing wells; and storage water rights ranging from
large jurisdictional reservoirs to residential ponds. Many of
our projects require preparation of substitute water supply
plans to allow operations to be initiated in advance of water
court approval of plans for augmentation. When required, plans
for augmentation are prepared for submittal to the water court.
Each plan provides the replacement water required to offset
out-of-priority depletions resulting from the operation and
presents the technical information required to ensure protection
of the rights of water users potentially affected by the
application.
Substitute Water Supply Plans
Delta and Montrose Counties, Colorado
Storage Water Right Application
Mesa County, Colorado
Western Water & Land prepared the technical documentation
required to support a storage water right application for a
36-acre reservoir located in Mesa County. The application was
filed to increase the decreed volume of the reservoir to reflect
the actual storage capacity. The work involved research of
historical files; detailed description of the existing
reservoir; topographic survey of the reservoir; calculation of
maximum storage, active-pool, and dead-pool volumes, accounting
for a Colorado Division of Wildlife minimum volume requirement
for piscatorial, wildlife watering, and recreation uses. The
actual volume of the reservoir was increased from the decreed
capacity of 251 acre feet to 580 acre feet.
Application for Plan for Augmentation
Mesa County, Colorado
Western Water & Land, Inc. prepared the technical documentation
required to support application for a plan for augmentation for
a proposed subdivision. Under the plan for augmentation, two
existing wells were used to supply water for the subdivision,
and water purchased from a Colorado Division of Water Resources
approved upstream reservoirs were used as the replacement source
for depletions attributed to the subdivision during times when
priority calls originate from senior water rights. Development
of the plan required calculation of water demand and stream
depletion modeling. Because the property is located within the
Gunnison River Basin, the plan provided for year-round
replacement of out-of-priority depletions.
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Abandoned Mine Land
Projects |
Western Water & Land personnel conducted an abandoned mine lands
project addressing human-health and ecological risks associated
with former operations at five abandoned uranium mines located
within a portion of the La Sal Creek Watershed in eastern Utah
and western Colorado.
Components of the project included planning document
preparation, comprehensive site characterization, risk
evaluation, and Engineering Evaluation/Cost Analysis (EE/CA)
document preparation. Planning documents include detailed Site
Safety and Health Plan (SSHP), Conceptual Site Model (CSM),
Field Sampling Plan (FSP), Quality Assurance Project Plan (QAPP),
and Community Relations Plan (CRP). Site characterization
activities include cultural resource surveys and recordation and
implementation of a comprehensive site investigation to obtain
the information required to evaluate the primary exposure
pathways identified in the CSM, assess human-health and
ecological risks, and support development and analysis of
potential removal action alternatives through implementation of
the EE/CA process.
The characterization effort included collection and
analysis of abiotic samples (surface water, soil, sediment, and
mine waste rock), biotic samples (benthic macroinvertebrates,
irrigated crops, garden produce, grasses, forbs, and shrubs),
gamma-exposure surveys at each mine, and radon monitoring at the
mines and within the homes of nearby residents. Three distinct
reference areas were established to assess background conditions
for the sampled media, gamma-exposure rates, and radon levels.
Samples were analyzed for an extensive schedule of inorganic
parameters, metals, and radionuclides. All work was conducted
in accordance with the requirements and procedures specified at
OSHA 1910.120.
Results of the characterization
effort were used to perform a streamlined risk evaluation of the
human-health and ecological threats posed by former operations
at the mines. Analytical results were compared to specific
risk-based benchmarks for the human-health and ecological
receptors and exposure pathways identified in the CSM. The
benchmarks used in the evaluation included state and federal
standards and risk management criteria established by the BLM.
An EE/CA was performed to screen, develop, and evaluate
potential removal action alternatives for reducing the
human-health and ecological threats associated with the five
mines. The EE/CA was developed in accordance with the
procedures established by the EPA for non-time critical removal
actions under CERCLA and the NCP. The EE/CA was completed in
2005 and issued for public comment in 2006.
The New Dominion Mine is an abandoned/inactive mine located
in San Miguel County,
Colorado. The mine, consisting of two separate mine adits and
associated waste-rock dumps, is located on public land adjacent
to the town of Ophir. Water discharging from the mine adits
discharges to a natural wetland area located on private land
which ultimately drains into the North Fork of the San Miguel
River.
The project involved characterization of the mine waters,
material comprising the waste-rock dumps, precipitates deposited
along the mine drainage channel, and sediment and vegetation
within the wetland area. Characterization results were used to
assess general nature and extent of contamination within the
sampled media, performance of the wetland in passive treatment
of water discharging from the mine, the human-health and
ecological risks posed by surface water and waste rock at the
mine as well as surface water, sediment, and vegetation within
the wetland. Project results are being evaluated to assess the
additional actions, if any, required to ensure protection of
public health and the environment.
Elk Tunnel is an abandoned mine located on public land within
the historic Animas Mining District near the town of Silverton,
Colorado. The project was a component of a basin-wide
reclamation effort designed to reduce metals contamination
impacts to human health and the environment within the Upper
Animas River Basin. Elk Tunnel was identified as one of the
priority sites within the basin because drainage from the mine
contributes significant metal loading to Cement Creek, a primary
tributary to the Animas River.
The work performed for this project involved preparation of an
EE/CA designed to address the human-health and ecological
threats posed by water discharging from the collapsed adit at
the mine and the engineering design required to implement the
removal action selected to reduce metals concentrations in water
discharging to the creek. The mine site was characterized based
on information generated during previous investigations
conducted within the Cement Creek drainage, including studies
performed by the Colorado Water Quality Control Division, BLM,
Colorado School of Mines, and Colorado Division of Minerals and
Geology. Through the characterization effort, the metals
identified as being of primary concern in the adit drainage
included aluminum, iron, manganese, and zinc.
The removal action alternative selected on the basis of the
EE/CA involved construction of an open channel in combination
with three settling ponds. The alternative was designed to
promote pH neutralization through limestone dissolution, provide
aggressive aeration/oxidation through open channel segments, and
maximize onsite storage capacity for the collection of metals
precipitates. The action has been implemented at the mine and
is currently providing passive treatment for reduction of metals
in water discharging to the creek.
The scope of work involved (1) preparing a Sampling and Analysis
Plan (SAP) for water and a SAP for soil/waste rock describing
the procedures to be used to assess each medium, (2) preparing a
Site Safety and Health Plan (SSHP) describing the health and
safety procedures and protocols to be implemented during the
characterization effort, (3) measuring gamma-exposure rates at
the mines, (4) collecting waste-rock and surface-water samples
at the mines for laboratory analysis, (5) measuring radon levels
within each mine portal and in a background area adjacent to the
mines, and (6) conducting a screening-level risk evaluation to
assess the relative hazards to human health and the environment
posed by the mines.
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Permitting & Environmental
Compliance Projects |
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Fish Inlet/Outlet Design
Mesa County Colorado
Western Water & Land was retained by a major sand and gravel
operator to design a native fish inlet and outlet for an
existing sand and gravel mine on the floodplain of the Colorado
River. The project involves the design of a fish inlet and
outlet for recovering native fish on the Colorado River. The
inlet will allow for the flooding and development of propagation
back water areas in the gravel mine pit.
The design is intended for annual sedimentation to occur in the
pit lake during flood stages eventually leading to natural
reclamation of the lake area. The agencies involved include the
Colorado Division of Minerals and Geology, the U.S. Army Corps
of Engineers, and the Colorado Department of Wildlife (Fish and
Game Division). Inlet design will involve a hydrologic study of
flood frequency, HEC-RAS modeling, MIKE21 modeling of river
hydraulics, and channel sedimentation and erosion, and structure
design (for annual and 100-year flood events). Surveying of
several river transects was necessary to conduct the hydraulic
analysis.
Regulatory Compliance
Parachute, Colorado
Western Water & Land personnel provided regulatory compliance
services to the Unocal Corporation in support of reclamation
activities at the former Parachute Creek Shale Oil Facility.
Services have included contingency planning, stormwater
permitting, annual hydrologic monitoring reports for the
Colorado Division of Minerals and Geology, annual RCRA
groundwater monitoring reports for the Colorado Department of
Public Health and Environment, closure documentation required
under RCRA, mine permit technical revisions, and mine permit
termination. Our professionals have also assessed the
permitting requirements associated with closure operations and
have designed and implemented verification programs to document
that closure performance standards have been attained.
Mining Permits and Technical Revisions
Piceance Basin, Colorado
Western Water & Land is well-experienced in the preparation of
mining permits including 112 permits, permit amendments,
technical revisions and annual permit reports. Western Water &
Land personnel were responsible for the conceptual design and
preparation of technical revisions to existing mining permits
associated with closure activities for two large oil shale
mining sites. One technical revision included the development
of the conceptual hydrogeologic flow model of an inactive
underground oil shale facility and subsequent drainage of mine
waters. Anticipated future work will include an additional
technical revision that will document proposed passive water
treatment of mine water discharge. This will also require a
permit to treat mine water discharge under the Colorado
Department of Health and Environment. Further permit revisions
may include significant reclamation activities and
modifications.
Western Water & Land
personnel have prepared annual reports required by the Colorado
Division of Minerals and Geology. Annual reports have been
prepared for several of our mining clients over the last several
years. These reports summarize the status of reclaimed lands,
reclamation activities within the past year, and future
reclamation plans.
Wetland Delineation
Mesa County, Colorado
Western
Water & Land, Inc. conducted wetland delineations of all ditches
and other potentially disturbed surface areas that may be impacted by
construction of municipal diversion project. Wetland
delineations were conducted along the potentially affected
features in accordance with U.S. Army Corps of Engineers
requirements. Western Water & Land performed comprehensive
vegetation surveys along the affected areas which were followed
by excavation of test pits to support delineation of the wetland
boundary with soil and hydrology information. The wetland
boundaries was established in accordance with the three wetlands
criteria parameters of hydrophytic vegetation, hydric soils, and
hydrology indicators.
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Soil & Sediment
Assessment Projects |
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Firing Range Remediation
Grand Canyon National Park, Arizona
Western Water & Land conducted a complete characterization and
remediation of two small-arms firing ranges the National Park
Service (NPS) at Grand Canyon National Park. The first phase of
the project involved soil contaminant characterization of
surface and subsurface soils. This was conducted by performing
electronic metal scans followed by sampling and analysis of
soils surrounding and within the target backstop berm. Western
Water & Land determined that lead and other metal contamination
was limited to the upper 18-inches of most soil horizons, and
designed a remediation phase to collect and treat all
contaminated soils.
The top 18-inches of soil was excavated and screened through
vibrating screen decks. The ¼-inch plus fraction was then fed
through a shaker-table separator to separate all of the coarse
bullet fragments from the fine soil particulates. The fine
soils were treated with a phosphate-based reagent to immobilize
the fine fraction of lead and other metals in the soils.
Testing of the resulting soil showed lead levels below EPA and
Arizona soil screening Levels. The soils were then reused by
the NPS to construct new, state-of-the art firing range
backstop.
RCRA Facility Investigation
Parachute, Colorado
A Resource Conservation and Recovery Act (RCRA) Facility
Investigation was conducted at the former Parachute Creek Shale
Oil Facility. The investigation was conducted pursuant to an
Order on Consent between the facility and the Colorado
Department of Public Health and Environment (CDPHE). The focus
of the project was to evaluate the nature and extent of any
constituent releases from EPA- and Owner-identified solid waste
management units (SWMUs) associated with retort testing and oil
shale upgrade operating areas. Results of the investigative
component of the project were used to design and implement the
necessary corrective actions needed to close the facility.
The investigative component of the project included preparing
planning documents (work plan, quality assurance/quality control
plan, data management plan, and safety and health plan) and
collecting the surface and subsurface information needed to
assess geochemical conditions in background areas, within the
SWMUs, and downgradient of the SWMUs. The resulting analytical
data were validated and used to construct a project database. A
Corrective Action Plan was prepared to document the recommended
corrective actions identified on the basis of investigation
results. Following CDPHE approval of the plan, the recommended
corrective actions were implemented, and once completed, CDPHE
provided certification that the actions had been properly
completed and no further actions were required at the site.
Radiological Characterization
Moab, Utah
A subsurface soil investigation was conducted in support of the
baseline radiological soil characterization at the Moab Mill
Site located near Moab, Utah. The purpose of the
characterization was to provide the data needed to assess
radiological levels as well as the lateral and vertical extent
of contaminated soil in areas where subsurface contamination was
expected on the basis of site history and operational
practices. The scope of work was designed to provide the
information needed to assess the risk associated with soil
excavation and to estimate the volume of contaminated soil that
will be removed during reclamation.
The activities performed to complete the characterization
included (1) excavating test pits in areas of suspected deep
contamination, (2) collecting soil samples on one foot intervals
within each test pit, (3) scanning each sample with a NaI gamma
detector to assess estimated radium-226 (Ra-226) activity, and
(4) submitting selected samples to an analytical laboratory for
analysis of Ra-226, and in some cases, natural uranium (Unat)
and thorium-230 (Th-230). Each test pit was extended from the
ground surface to the depth where NaI detector readings
indicated that Ra-226 activities were below the Uranium Mill
Tailings Radiation Control Act (UMTRCA) 5/15 Pico Curies per
gram standards. All work was conducted in accordance with the
procedures and protocols specified in a work plan and
site-specific safety and health plan prepared for the
characterization.
Soil Geotechnical Assessment
Parachute, Colorado
Western Water & Land personnel conducted a geotechnical soils
and slope stability investigation to support Williams Field
Services in the design and construction phases of the American
Soda, L.L.P. solution mining pipeline. Two twin 44-mile long
subsurface pipelines were to be constructed to transport high
temperature sodium bicarbonate water and recycled water between
the American Soda solution mining facility located at a remote
site in Rio Blanco County and the processing facility located in
Parachute, Colorado.
The geotechnical investigation involved the collection and
laboratory analysis of subsurface soil samples at 22 stations
along the 44-mile pipeline right-of-way. The objective of the
geotechnical investigation was to identify soil type and
properties from designated sampling sites along the pipeline
alignment. Soils were collected using standard hollow-stem
auger and hammer techniques. Samples were submitted for
analysis to a local geotechnical laboratory.
Analyses included: Laboratory Determination of Water (Moisture)
Content of Soil and Rock by Mass (ASTM D-2216); Particle-Size
Analysis of Soils (ASTM D-422); Laboratory Compaction
Characteristics of Soil Using Standard Effort (Standard Proctor
- 12,400 ft-lbf/ft3) for samples below the first
depth interval (ASTM D-698); Laboratory Compaction
Characteristics of Soil Using Modified Effort (Modified Proctor
- 56,000 ft-lb/cu. ft.) (ASTM D-1557); Liquid Limit, Plastic
Limit, and Plasticity Index of Soils (ASTM D-4318);
Classification of Soils for Engineering Purposes using the
Unified Soil Classification System (ASTM D-2487); and
Description and Identification of Soils - Visual-Manual
Procedure (ASTM D-2488).
The soil test data was used by Perma-Pipe, a subcontractor of
Williams, to obtain pipeline installation requirements using
modeling techniques.
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Stormwater Management Projects |
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Stormwater Control Plan
Logan Wash Mine - Garfield County, Colorado
Western Water & Land prepared
a stormwater control plan to address stormwater control
measures to be implemented at the Logan Wash Mine as part of
final reclamation. The goal of stormwater control at Logan
Wash Mine is to minimize hydraulic damage resulting from
significant storm events by providing suitable stormwater
conveyance structures at the mine to transport water to
natural drainages.
The main objective of the routing plan was to control storm runoff that
originates on upgradient areas, mine benches, and roads such
that high-energy runoff does not cause extensive erosion of
these and downslope areas including faces of mine dumps, and
outslopes below road cuts. Peak discharge at the mine site
was estimated for a selected rainfall intensity event and
specifications were prepared for stormwater conveyance
structures of appropriate design capacity.
The stormwater control plan focuses on the collection and diversion of
storm runoff in channels that convey the water to several
main discharge points or outlets. Outlets were designed
with the appropriate riprap materials required to
sufficiently armor the high velocity outlet features. The
plan was submitted to and approved by the Colorado Division
of Minerals and Geology as a technical revision to the
mine’s reclamation permit.
Watershed/Drainage Basin Delineation
Mesa County, Colorado
A study was performed for the Mesa County Department of Public
Works to delineate the major watersheds and drainage basins
contributing stormwater runoff to the Grand Valley in western
Colorado. The study was conducted to provide the County with a
comprehensive assessment of the basins impacted by current and
future development in the valley and to support the county’s
proposed Phase II NPDES-compliant stormwater management
program.
The work involved review and compilation of existing information
from previous watershed/drainage studies in the area; field
verification in areas where existing information was either
lacking or suspect; and preparation of GIS map files displaying
watershed/drainage basin boundaries with cross links to data
tables listing the drainage reports for each basin that are on
file with the county. The resulting map files were used by the
county to develop a web-based interactive map of the drainage
basins included in the study.
Stormwater Management Planning and Permitting
Parachute, Colorado
A stormwater management program was developed for Unocal’s
Parachute Creek Shale Oil Facility. The program was developed
pursuant to the requirements specified in the facility’s general
permit for stormwater discharges associated with heavy
industrial activity. The program addressed discharges from site
operational areas, as well as those areas where current and
future site closure activities may reasonably be expected to
impact the quality of stormwater discharges.
The program included identification of potential pollution
sources associated with current and future industrial
activities, and implementation of best management practices to
reduce pollutants in stormwater discharges. Western Water &
Land personnel were also responsible for evaluating stormwater
monitoring data and preparation of annual stormwater reports for
submittal to the Colorado Department of Public Health and
Environment.
Stormwater Management Planning and Permitting
Moab, Utah
A Stormwater
Pollution Prevention Plan (SWPPP) was prepared to support
remediation/construction operations at the Moab Mill Site in
Moab, Utah. The plan was prepared in accordance with the
provisions specified in the State of Utah’s Stormwater General
Permit for Construction Activities (Permit No. UTR100000). The
SWPPP covered construction activities to be implemented at the
Moab Mill and Tailings Disposal Area in accordance with the
Technical Specifications contained in the Final Reclamation Plan
approved by the U.S. Nuclear Regulatory Commission (NRC) for the
site.
The SWPPP addressed each of the required elements specified in
the Part III of the General Permit (No. UTR100000 ). Additional
details regarding minimization of emissions of fugitive dust,
spill prevention and control, erosion control,
interception/storage of sediment-/contaminant-laden runoff,
avoidance of operations during periods of high thunderstorm
potential, and mitigative measures associated with potential
borrow areas was provided in a companion document, Site
Management Plan, which was also prepared for the site.
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Environmental
Program Management Projects |
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Mine Closure Program
Piceance Basin, Colorado
 Western Water & Land personnel managed all environmental
programs associated with closure of two former oil shale facilities in the Piceance Basin,
Colorado. Responsibilities included design and implementation
of hydrological monitoring programs and special investigations
involving fate and treatment of mine water; land reclamation and
revegetation of disturbed areas; oversight of NPDES-compliance
programs; administration of mine permit compliance, federal
leases, and rights-of-way; design and negotiation of land
reclamation with federal agencies (USBLM and Colorado DMG);
interfacing with state agencies (CDPHE) on water quality issues;
facilitation of potential lease and mine permit transfer; bond
calculations; preparation of large construction (demolition) bid
documents; and supervision and administration of on-site
operation and maintenance personnel. Western Water & Land
personnel served as the primary points of contact for all
closure operations at Occidental Oil Shale’s Cb Tract and Logan
Wash mine sites.
Facility Closure
Parachute, Colorado
Western Water & Land
personnel provided program management services for closure
operations conducted at the Parachute Creek Shale Oil Facility
located near Parachute, Colorado. Management
and technical oversight was provided for services involving
investigative studies and reporting, corrective action
operations, and regulatory compliance. Investigative studies
included RCRA Facility Investigation, facility-wide chemical
sewer investigation, hazardous waste inventorying at a shale oil
retort complex, and various hydrologic assessments for specific
site operational areas. Corrective action operations included
petroleum product recovery, removal and disposal of contaminated
media, treatability testing, basin closures, and reclamation
verification. Regulatory compliance activities included mine
permit compliance, stormwater permitting, contingency planning,
annual reporting in accordance with DMG and CDPHE compliance
monitoring requirements, support during CDPHE annual
inspections, and closure planning and reporting.
Remedial Investigation/Interim Response Action
Rocky Mountain Arsenal, Colorado
Western Water & Land
personnel provided program management services for a large-scale
remedial investigation and an interim response action at the
Rocky Mountain Arsenal (RMA), located near Denver, Colorado.
Remedial investigation activities included comprehensive
assessment of the nature and extent of groundwater contamination
beneath the 27-square mile facility. In addition to providing
management and technical oversight of investigative and
reporting activities, services also included assisting RMA
personnel during discussions/negotiations with other potentially
responsible parties, state and federal regulatory agencies, and
the public. Services in support of an interim response action
included evaluating fate and transport of offsite contamination
from the facility, designing a response action to mitigate the
offsite contamination, developing construction drawings and
specifications, construction cost estimating, and technical
oversight during construction of a resulting $10 million
groundwater extraction, treatment, and recharge system.
Remedial Investigation/Feasibility Study
Monticello, Utah
Western Water & Land personnel provided program management
services for design and implementation of a Remedial
Investigation/Feasibility Study (RI/FS) focusing on surface
water, groundwater, and stream sediment contamination resulting
from former operations at Monticello Mill Tailings Site, located
in Monticello, Utah. The RI/FS included characterizing the
nature and extent of radionuclide and metals contamination in
each of the media, groundwater flow and contaminant transport
modeling, evaluation of potential impacts to ecological
receptors of concern, assessment of human health and ecological
risks, and application of EPA’s Superfund Accelerated Cleanup
Model including preparation of the Engineering Evaluation/Cost
Analysis documentation required to implement removal actions
under CERCLA. Services included supporting Department of Energy
personnel during discussions with state and federal regulatory
agencies and the public.
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