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- Utility mapping at
appropr=
iate
levels
- Utility coordination<=
/li>
- Utility relocation de=
sign
- Utility condition
assessm=
ent
- Communication of
utility=
data
- Utility relocation op=
inion
of cost=
s
- Implementation of uti=
lity
accommo=
dation
policies
- Utility design
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- A branch of engineering practice that involves managing certain ris=
ks
associated with:
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- Surveyed to project tolerances;
- Plotted and mapped into the project CADD or GIS systems;
- Reviewed along with all project documentation and utility owner rec=
ords
by the registered professional in responsible charge of the entire
process.
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- Surface Geophysical Methods used to search for and trace existing
utilities.
- Designated utilities are then surveyed and plotted on site plan.
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- Utilities exposed via non-destructive air-vacuum means
- Exposed utilities are then surveyed and plotted on site plan Elevations, Size, Conditio=
n,
Materials, Precise Horizontal Positions are measured and documented=
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- Engineer: Risk is usually limited to due diligence in records resea=
rch
and interpretation.
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- Engineer: Assumes risk for the accuracy and completeness of the
surveyed and plotted visible features in addition to due diligence =
in
records research and interpretation. The engineer also assumes risk=
for
their correlations of utility record data to plotted utility
appurtenances.
- Owner: Risk is similar in nature to that of QL D. However, risk is reduced b=
y the
potential identification (by their appurtenances) of utilities not =
of
record and by a higher horizontal mapping reliability achieved thro=
ugh
correlation of records to surveyed and plotted appurtenances.
- Constructor: Risk is similar to that of QL D. However, risk is reduced b=
y the
potential for a design that takes into account better utility
information.
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- Engineer: Assumes risk for losses caused by negligent errors or
omissions in the selection and application of surface geophysical
methods and their interpretations and reductions of utility data on=
to
the documents. A surf=
ace
geophysical search may (a) identify utilities not of record, (b)
indicate the path of utilities between surveyed and plotted
appurtenances, (c) indicate the path of utilities where no appurten=
ances
exist, and (d) assist=
in the
interpretation of record data.
- Owner: Risks due to unknown, undiscovered, incorrect, or difficult =
to
interpret records are greatly reduced. Designers have ability to =
design
structures and construction footprints with higher reliance upon ho=
rizontal
utility information, reducing owner’s redesign costs and
unforeseen construction conflicts costs.
- Constructor: Utility information is more comprehensive and accurate=
in
the horizontal plane, reducing safety risks and increasing reliabil=
ity
of bids.
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- Engineer: In addition to the applicable standard of care and any o=
ther
additional standards imposed by commercial indemnity clauses, the
accuracy of quality level data is also typically guaranteed to stat=
ed
tolerances.
- Owner: No risk, other than that caused by own negligence.
- Constructor: No risk, other than that caused by own negligence.
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- Engineers will need to find a way to perform to this standard
- Develop resources in-house
- Contract with sub-consultant
- Can contractually shift some risk
- Since risk of tort liability remains with Prime Consultant, it is=
to
their advantage to be careful in selection process due to increas=
ing
costs for utility errors / omissions.
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- Each project needs to be looked at individually
- Most times, QL C with selective QL A is sufficient.
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- Begins Project Evaluation (site visit and records research)
–Submits a cost estimate for QL D mapping plus aerial invento=
ry.
- Upon approval of the estimate, the subsurface utility engineer crea=
tes a
QL D map using available base mapping, if any.
- The engineer uses this QL D map to evaluate project for utility
risks. Verbal or writ=
ten
reports may be generated if desired.
- The engineer prepares Prelim Utility Cost Estimate for Budget purpo=
ses.
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- ENGINEER specifies level of utility mapping
- ENGINEER forwards QL D map to task designers
- Hydraulics,
- Structures,
- Right of Way,
- Roadway Design
- Others
- Task Designers select specific areas/utilities where early QL A dat=
a may
assist in broad design decisions
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- May move line and grade of roadway to avoid high-dollar utility und=
er
pavement, such as fiber optic duct, large water line/gas line.
- May want to know if portrayed utility is a large duct or pipe versus
direct buried cable or small distribution pipe.
- May want to know general depth of high dollar utility in order to m=
ake
early decisions on general depths of drainage / placement of retent=
ion
ponds
- May want to know exact location of utility for design of nearby
structures, such as piers, walls, etc. without necessary utility
relocation
- May want to know if utility is unequivocally under paving or out-of=
-pave
for early cost reimbursement budget issues
- Material of utility (I.e. Asbestos cement / low grade pvc) may indi=
cate
automatic replacement.
- Others?
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- Engineer “sets up” QL A location using surface geophysi=
cs.
- If surface geophysics indicates QL D position of utility is
sufficiently different as to negate this early need for data, QL A=
data will not be gathered=
at
this location at this time.
- QL A data gathered and mapped.
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- Engineer executes mapping (QL C / QL B upgrades) as per scope. Note that the early QL A d=
ata may
create need to revise original scope.
- SUE deliverables furnished to task designers for their consideration
during design (30% - 60% stage, typically).
- Designers should use this QL B / QL A data to avoid utility relocat=
ions
when possible.
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- Continues design. At =
60%
design stage, task designers re-evaluate design status for addition=
al QL
A requests and forward to subsurface utility engineer for collectio=
n and
depiction
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- Shapes of drainage pipe (elliptical vs round)
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