The Alpine Pipeline System was originally constructed during the winter of 1998/1999. The
pipeline crosses three major rivers between the Alpine Development CD1 facility and its tiein
to the Kuparuk Pipeline. These three river crossings include the horizontal directionally
drilled (HDD) crossing of the East Channel of the Colville River; and the two aboveground
crossings of the Kachemach River and the Miluveach River.
Monitoring of the HDD crossing was first conducted in 2001 (Baker 2002). From 2003 through
2006, annual monitoring of the HDD, Kachemach River, and the Miluveach River crossings
was conducted (Baker 2003, 2004, 2005, 2006). Over the course of the previous five years’
monitoring events, no significant scour, erosion, or VSM tilt were observed at the Kachemach
and Miluveach River crossings. As a result, in the fall of 2006 a five-year monitoring interval
was recommended. Therefore, in 2007, monitoring was limited to the HDD crossing (Baker
2007).
The 2008 monitoring, including surveying by Kuukpik/LCMF, LLC (LCMF), was conducted
at all three crossing locations (Baker 2008). In 2009, LCMF surveying was conducted only at
the HDD crossing location. Visual observations and tilt measurements were conducted at all
three locations. It is anticipated that LCMF will continue to provide annual bank erosion
survey data for the HDD crossing, and that bank erosion surveying of the Kachemach and
Miluveach will occur again in 2013.
Monitoring is conducted to document the condition of the pipelines and channel morphology
at each of the river crossings. Monitoring also allows for a comparison between observed
conditions and the design criteria, as required by Right-of-Way Lease/Grant Stipulations and
the Alpine Surveillance and Monitoring Program. The primary objective is documentation of
the state of the pipeline at each crossing, as well each pipeline’s affect on the channel.
