statement of qualifications pipeline, oil and gas services - Hatch Mott ...

Source of Supply Transmission Main
Location
St. Charles County, Missouri
Client
Missouri-American Water
Services
Hydraulic Analysis
Design
Plans and Specifications
Cost Estimates
Permit Applications
Surge Analysis
Const. Administration
Resident Observation
Construction Estimate
$5.5 million
Actual Construction Cost
$5.6 million
Construction Completion
1997
Contractor
Michels Directional
Crossings
817 W. Main Street
PO Box 128
Brownsville, WI 53006
(920) 924-4300
Project Description
In order to obtain approximately 30 million gallons per day of additional supply for their St.
Charles District service area, Missouri-American Water constructed an interconnection with the
City of St. Louis water system. The project involved the construction of approximately 20,000
feet of 20- and 36-inch diameter pipe and a metered interconnection with the City of St. Louis.
Also included was a 4,692-foot crossing of the Missouri River performed by the method of
horizontal directional drilling (HDD). The 36-inch pipeline was designed as steel, ductile iron,
and prestressed concrete cylinder pipe for alternate bids.
The horizontally drilled crossing of the Missouri River was one of the longest large diameter
crossings performed at that time. Trenchless technology was the construction method of choice
due to the need to maintain the integrity of the levee system bordering the river, and the
unpredictable nature of the Missouri River. As the bottom profile of the Missouri River
constantly changes, particular attention was paid to preconstruction surveys of the channel and
the depth of installation.
The transmission main alignment involved cross-country pipe installation through an area of
Missouri flooded in 1993 and 1995. Construction was carefully scheduled to avoid periods of
high river stage and minimize disruption of the City of St. Louis’ water treatment plant.
HMM Role
Hatch Mott MacDonald (HMM) was responsible for all aspects of the transmission main design,
and prepared plans, specifications, cost estimates, and permit applications. Design of the
directionally drilled crossing included thickness and material selection, corrosion protection,
selection of alignment and grade, and geotechnical investigation.
Project Highlights
• 4,692-foot HDD Crossing of the Missouri River.
• One of the longest large diameter crossings performed at that time.
• Maintained integrity of levee system bordering the river.