EPA NARMPA Locational Data and Site Data Management Presentation
23rd Annual NARPM Training Program
Locational Data and
Site Data Management
Robert M. Alvey – Geologist R2
ERRD/PSB – Technical Support Section
23rd Annual NARPM Training Program 1
Location, Location, Location!
The primary criteria for value in real estate!
Location is a critical component for Superfund
Property boundaries – physical and “groundwater”
Site hydrogeology and risk assessment
Planning – RI/FS/RA/LTM, etc.
23rd Annual NARPM Training Program 2
Location IS Data
Locational data is a key element of Superfund site
Inaccuracies in locations can cause:
Inaccuracies in maps
Inaccuracies in location and extent of contamination
Inaccuracies in monitoring well locations and screens
Inaccuracies in Site features
Inaccuracies in groundwater gradients
Inaccuracies in fate and transport modeling
Incorrect development of a conceptual site model
Inaccuracies are carried along through the project
23rd Annual NARPM Training Program 3
Location, Location, Location??
“Location” consists of X, Y, and Z components
The Earth is NOT flat
Maps are projections of 3D surfaces onto flat surfaces
The components need to be referenced
Measuring system used and scale needs to be noted
The locational data needs to be related to other
Where the sample was collected
Where and what type of measurement was made
Date the data or sample was collected
23rd Annual NARPM Training Program 4
Location, Location, Location
“X” and “Y”
Two points needed to locate a “surface” position
Horizontal datum: North American Datum of 1983
• NAD83-91 (a 1991 adjustment – Oregon, Idaho, Washington)
• HPGN – High Precision Geodetic Network
Orientation – “North” or local benchmark
For projections onto a flat surface
• Latitude and Longitude (EPA Preference)
• State Plane Coordinates
23rd Annual NARPM Training Program 5
Location, Location, Location
“Z” Elevation or Altitude
NGVD29 – National Geodetic Vertical Datum of 1929
NAVD88 – North American Vertical Datum of 1988
FBGS – Feet Below Ground Surface
• Used primarily for field drilling or sampling to measure depths
NGVD29 and NAVD88 are based on mean sea
level. NAVD corrected minor errors in NGVD
Note: Yes, sea level is changing.
23rd Annual NARPM Training Program 6
Location, Location, Location
The accuracy of a measurement is the degree of
closeness of measurements of a quantity to that
quantity's actual (true) value.
The precision of a measurement is the degree to which
repeated measurements under unchanged conditions
show the same results (repeatability)
A measurement is considered valid if it
is both accurate and precise
23rd Annual NARPM Training Program 7
Linking “locational” data to your site data:
Improves planning of field activities
Improves accuracy in maps and figures
Increases efficiency of drawing preparation
Improves planning and decision making process
RPMs collect many sample analyses. Make certain to
know WHERE they were taken.
23rd Annual NARPM Training Program 8
Spatial data having a description and
documentation of its subject matter:
how, when, where, and by whom the data was
availability and distribution information;
its projection, scale, resolution, and accuracy;
its reliability with regard to some standard.
Metadata consists of properties and
documentation of the data itself.
23rd Annual NARPM Training Program 9
Collecting Locational Data
Various tools and methods available
Survey, Aerial Photography, GPS, eyeball*
Each method has different accuracies and
Documenting the method used is important
Metadata – helps refine locational measurements
*Yes! Your eyeball IS a “valid value”. It may not be
fully accurate or precise, but is useful.
23rd Annual NARPM Training Program 10
Surveying – Plan with details
Bench marks: Local, USGS, etc. Referenced!
Wells: Critical to obtain precision and accuracy for
measuring point elevations
When having additional survey done, make sure
to obtain measurements at existing point(s) to
have all elevations on same plane
23rd Annual NARPM Training Program 11
Navy site: NJ
Innovative pilot to use nano-iron injection
OU map with wells provided. Groundwater flow
Injections and monitoring.. NOTHING
OU map displayed on full base map revealed
overall groundwater flow was in opposite direction
Look at the big picture before concentrating on
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Fed Lead site: NY
Extensive monitoring well network
High level QA/QC for all phases
Survey* results indicated well elevations incorrect
by 30 FEET
Hired USGS to resurvey to 0.001 foot precision
All reports and records have incorrect elevations
Note: Surveyor* was fully licensed and
experienced.. In Pennsylvania
23rd Annual NARPM Training Program 13
Examples of Data to be Submitted Electronically
• Preference is for GIS layer file or computer-aided design (CAD) format with all relevant surface
features; however, PDF or other file format may be acceptable.
Boring Logs and Well Construction Details:
• X, Y, and Z coordinates, and location ID.
• Ground surface elevation, top of casing elevation, depth to lithologic units, lithologic descriptions, depth
to well construction material, well construction material type, diameter of casing, drilling method, well
development information, etc.
• Field test data [e.g., photoionization detector (PID), field x-ray fluorescence (XRF), immunoassay, etc.].
• Aquifer slug test or pump test data.
• Geophysical test data.
• X, Y, and Z coordinates.
• Coordinate system and projection in use.
Water Level Data:
• Location ID and X, Y, and Z coordinates.
• Depth to water.
• Date and time of measurement.
• Measurement equipment or system used.
Note: Appendix to the Ground Water Forum’s fact sheet, “Electronic Data
Deliverables: The Importance of Receiving Your Site and Project Data
Electronically,” provides supplemental information. 2011
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Important regardless of database software used
Anticipate changing technologies
Anticipate that someone would like to use your
Incorporate locational requirements in Contracts
Agreements and Orders
EPA is preparing updated guidelines for locational