Verification of Wastewater Utilities and
Geometric Networks for Marine Corps Air
Station (MCAS) Cherry Point, North
Carolina
Roger K. Cottrell, Jr., PMP, GISP
May 9, 2012
Morgantown, WV
Overview
• History of MCAS Cherry Point and GIS at MCAS
Cherry Point, North Carolina
• Existing Wastewater System at MCAS Cherry
Point
• Wastewater Project Problem Statement
• Wastewater Project Goals
• Wastewater Project Planning
• Project Process
• Project Results
• Lessons learned
History of MCAS Cherry Point
• MCAS Cherry Point
opened in 1941
• The Air Station
encompasses
29,000 acres and is
equal in size to a
small city
Mission: “To provide the highest quality aviation facilities,
support, and services to promote readiness, sustainment,
and quality of life for Marines, Sailors, civilian Marines,
family members and others associated with MCAS Cherry Point.”
History of GIS at MCAS Cherry Point
• GIS program commissioned in 1996
• GIS is under the Facilities Systems Support
Office (FSSO)
• Has evolved into a highly developed, mature
enterprise GIS program serving multiple
departments
• All spatial data is GEOFidelis Model
compliant based on Spatial Data
Standard for Facilities, Infrastructure,
and Environment (SDSFIE v.6)
• Enterprise ESRI shop
Wastewater Problem Statement
• Wastewater system data scattered
between several departments in
different formats
• Existing data outdated and incomplete
• Existing data inaccurate
• Existing data inadequate for use in any
meaningful capacity
• URS was commissioned to improve the
existing wastewater dataset under an
existing contract
Wastewater Project Goals
• Integrate disparate datasets (CADD, hard copy,
and GIS) into a complete GIS dataset
• Verify location of existing wastewater features
using GPS
• Conflate and update existing attributes
• Establish topology
• Make final dataset GEOFidelis-compliant
• Enhance locational quality of data
• Build geometric network and calculate
system capacity
• Draft executive summary report
Wastewater Project Planning
•
•
•
•
•
•
•
•
•
Statement of Work
Milestone and Deliverable Schedule
Resource Management Plan
Quality Management Plan
Progress Reporting Plan
Data Management Plan
Communication Plan
Safety Plan
Assumptions and Constraints
Project Process
1. Research and planning
2. Existing data acquisition and
integration
3. Feature location verification
using GPS
4. Spatial layer creation
5. Geometric network and
system capacity
6. Quality assurance/quality
control
Project Process
• Research &
Planning
– Meetings with
subject matter
experts
– As-built plan
acquisition and
review
– Non-spatial data
acquisition and
quality
– Local knowledge
Project Process
• Existing data acquisition and integration
Project Process
GEOFidelis-compliant GDB – 11 feature
classes
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Wastewater_disposal_tank_point
Waterwater_fitting_point
Wastewater_grease_trap_point
Wastewater_grit_chamber_point
Wastewater_inlet_point
Wastewater_junction_point
Wastewater_line
Wastewater_pump_point
Wastewater_septic_tank_point
Wastewater_valve_point
Wastewater_oil_wat_sparatr_point
Existing GIS
Data
CADD files
Analog Plans
Project Process
Feature location/verification using
GPS – Data Work Flow
1.
2.
3.
4.
5.
6.
2-3 GPS teams
Work divided into geographic
sections and assigned to teams
Data was checked out of SDE
database in versions as PGDB and
placed on GPS units
Field crews updated the data and
check data back into SDE versioned
database
GIS Analysts checked out versions
and performed edits, topology and
attribution
Product was delivered as a PGDB
and integrated into the GEOFidelis
SDE database
Project Process
• Feature location/verification using GPS
• Trimble GeoXH receivers
• ArcPad QuickForms to generate
data dictionary and GUI
• Laser range finder for touch spots
• Collected 90 fixes per location
• 5% of features were resurveyed for
quality control
• Collected digital photos of each
feature and linked them in the GDB
Project Process
• Post-processing in Trimble GPS
Analyst extension
• Used 3 primary CORS stations
and 1 Backup
• Castle Hayne
• New Bern 6
• Pea Island
• Washington (backup)
Project Process
• Field GPS – Safety
• Field safety is job one
• Heat, confined spaces,
chemical and biological
hazards (snakes, bacterial,
poisonous plants)
• Near miss recorded on this
job
Project Process
• Spatial layer creation geometry
• GIS Analysts in the
office cleaned data
and built topology for
each layer using GDB
rules
• GIS Analysts added
attribution
Project Process
• Spatial layer creation - attribution
• GIS Analysts attributed each of the 11
datasets based on the Marine Corps’
GEOFidelis Data Model formulated from the
Spatial Data Structure for Facilities,
Infrastructure and Environment (SDSFIE)
v2.6
• Subject matter experts were consulted
throughout the process
Project Process
• Spatial layer creation
- attribution
• Layers were
attributed based
on GEOFidelis Data
Model
• Metadata was
added as well
Project Process
• Geometric network and system capacity
Project Process
• Geometric network
and system capacity
– A group of features,
including junctions and
edges, governed by preset
connectivity rules
– Allows users to model and
analyze a system (water,
wastewater, electric, etc.)
that has a defined flow
direction
Project Process
• System Capacity
– Modeled after similar study at the
City of Lawndale, California
– Enhanced geometric network with
volume capacity processes and
estimates
– Used Manning’s Equation to
calculate volume for wastewater
lines
– Incorporated operating capacities
of pump stations
– Calculations based on gal./day
Project Process
• System Capacity
Manning’s Equation:
• MCAS Cherry Point’s system is gravity fed.
•
Slope of wastewater pipeline
•
Diameter of wastewater pipeline
•
Wastewater volume flowing out of buildings
Where:
V = Velocity in feet/second
k = 1.49 for unit conversion
n = Coefficient of roughness of pipe material
S = Slope of wastewater line
Rh = Hydraulic radius
Project Process
Slope of pipe:
• Values to the right are the
minimum slope that gravityfed wastewater lines are
permitted to have in North
Carolina
• Due to the lack of data
available for slope, the
minimum required slope
was assumed for each pipe
diameter and local help
Project Process
Diameter of pipe:
• Using plans, URS updated many
wastewater lines that were
previously missing pipe diameters
• URS used plans from
Facilities and Engineering to
populate these missing attributes
• Pipes with empty values still participated in the network but
did not have a Percent_Capacity value in the flow
accumulation field
Project Process
Flow from buildings:
• Flow data was unavailable
• Estimates of gallons per day per type of
structure and total square feet of
structure
• Estimate sources:
– North Carolina’s minimum
design standards for sanitary sewer systems
– City of Lawndale, CA study
– URS professional experience to estimate the
sewage flow for the remaining buildings by
square foot – used engineering expertise from
URS Water
Project Process
Pump station capacity volume:
• 79 pump stations currently in the
GIS on Cherry Point’s main base
• Attributed capacities for 29 pump
stations using values provided by
SMEs
• Applied average rated capacity of
the 29 pump stations to the
remaining 50 pump stations
Project Process
• Quality control
Project Process
• Quality assurance
Detail check included using a
random number generator to
choose a representative sample
to check geometry and
attribution.
Product Results
Complete Dataset
Photo Linking
Geometric Network
Product Results
Lessons Learned
• Safety is most important aspect of all field work.
• Local knowledge (SME) is key to a successful
wastewater inventory.
• GEOFidelis/SDSFIE Data Model can be cryptic and
requires a steep learning curve early in the planning
process.
• Photo-linking proved to be a great asset to the client.
• GDB rules proved to be very beneficial during editing
process.
• QA/QC process must start during the initiation and
planning phase of the project to be most effective.
Acknowledgements
Roger K. Cottrell, Jr., PMP, GISP – Project Manager
Stephen Strain, GISP – Technical Coordinator
Alice Mouraview – Director, MCAS Cherry Point FACSSO
J. J. Chadwick – MCAS Cherry Point Subject Matter Expert
Sallie Vaughn – GIS Analyst and Field Technician
Laura Barrick – GIS Analyst and Field Technician
Mark P. Smith – Sr. GIS Analyst and GPS Expert
Cara Stackpoole – GIS Analyst and Field Technician
Matthew Riley – Field Technician
Contact: roger.cottrell@urs.com