The Mid-America Pipeline
LLC (MAPL) Western Expansion Project (WEP) pipeline loop segments is
expected to consist of the following construction activities:
-
Addition of
12 pipeline loop segments, six in Wyoming and six in New Mexico;
- Each of the
existing 23 pump stations along the pipeline in New Mexico, Colorado, Utah
and Wyoming is expected to be modified or upgraded. No new pump stations
are required.
- Installation
of associated above-ground facilities including valves, pig
launchers/receivers, markers, fencing and signs.
Increased delivery volume
to southeastern New Mexico requires modification to the existing MAPL system
including major equipment, pumps and drivers at existing pump stations.
Larger capacity pumps and increased horsepower drivers are necessary at the
pump stations for this increased volume.
Existing pump stations may
be upgraded or modified by re-rating pumps, changing pumps, uprating
drivers, relocating pumps, installing new units or modifying existing
facilities. Installation of above-ground facilities will be constructed in
association with the pipeline segment construction including valves, pig
launchers/receivers, markers, fencing and signs.
Mainline valves are
generally installed every 10 miles, or at edges of environmentally sensitive
areas, such as rivers. Mainline valve spacing generally will follow the
same spacing as the existing 10-inch/12-inch loop segments.
The MAPL WEP pipeline loop
segments will all be below the surface. Permanent surface facilities
associated with the new pipeline loops will include pig launchers/receivers
and valves. The existing pump stations are all above ground and upgrades to
these facilities will generally be above ground. Pump stations do contain
buried piping, and upgrades and modifications may be constructed below the
surface within the facility.
All mainline valves will be
constructed above ground and secured with appropriate safety measures. A
six-foot chain link fence will be constructed around valve sites located
near residential areas. (Return to top)
Clearing/Grading
Clearing, grading and other
disturbances of soil and vegetation on the Right-of-Way and Temporary Use
Areas shall be limited to the minimum area required for construction.
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Fences
MAPL will minimize the
disturbance to existing fences and will install gates or temporary fences
for the construction period as necessary.
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Access
Roads
During construction of the
pipeline loop segments, existing roads and the right-of-way will be used for
access as practicable. Access roads will be identified by signage
indicating which roads may be used. (Return to top)
Backfilling, sediment and
erosion control, water diversion, seeding, mulching, fertilization, and
post-construction monitoring will each be utilized to restore the area where
construction occurs. ( Return to top)
Best management practices
will be implemented to control erosion. All soil conservation features
(such as water bars, terraces, rip-rapped channels, grassed waterways, etc.)
which are damaged by construction will be restored, as nearly as possible,
to their pre-construction condition.
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The cover from the top of
the pipe to ground level will generally be at least 36 inches, except in
rocky terrain, where cover will be a minimum of 24 inches. The minimum
burial depth for highway crossings will be according to individual
overseeing agency requirements, generally four feet below the borrow ditch,
resulting in approximately 5.5 feet under the road surface.
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Large rivers and major
roads may be crossed by the horizontal directional drill (HDD) method where
geotechnical conditions are determined to be favorable based on testing.
Directional drilling helps to minimize the impact to endangered species and
important waterways.
Directional drilling
involves drilling a small pilot hole into the ground and then enlarging and
reaming the hole to the proper size. The directional drill rig then pulls
the drill and prefabricated pipe section back out in the opposing direction
from which it entered. This is called pullback.
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Boring techniques will be
used to cross major and secondary roadways where required by Federal, State
and local jurisdictions. Dirt roads or two-track trails will be open cut.
Some unimproved county roads may also be open cut with prior proper
authorization. ( Return to top)
Testing
Hydrostatic testing,
internal caliper testing, and radiographic testing of welds will all be
conducted prior to introducing product into the line. A cathodic protection
system will protect the system from corrosion.
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