1st Avenue North Water Main Replacement

WATER MAIN REPLACEMENT IN THE HEART OF DOWNTOWN BILLINGS

This City of Billings project (W.O. 19-01, Schedule 1 – 1st Avenue North Water Main Replacement)
includes replacing 3,460 lineal feet of 12-inch cast iron water main with new 12-inch PVC water main
from North 33rd to North 25th Street and replacing 3,250 lineal feet of 6-inch cast iron water main with
new 12-inch PVC water main from North 15th Street to east of the intersection of 1st Avenue North and
Highway 87. The project is located in a high traffic, business corridor in Downtown Billings and required
coordination with business owners for access and temporary water and preparation of detailed traffic
control plans for the 1st Avenue North corridor and the difficult intersection of 1st Avenue North and
Highway 87.

Some of the design challenges included: Temporary water for high water users (Northern Hotel, Jakes,
Clocktower Inn, etc), high groundwater, corrosive soils, and petroleum hydrocarbon contaminated
soils due to abandoned leaky underground storage tanks (LUST) sites. Sanderson Stewart successfully
tackled these challenges by designing the water main to be PVC with nitrile gaskets, designing cathodic
protection for ductile iron fittings, and the water main was designed offset from its original location to
help with traffic flow in 1st Avenue North and limit the need to provide major businesses with temporary
water. To minimize utility conflicts during construction, Sanderson Stewart hired a subcontractor to
vacuum excavate approximately 30 utility crossings during design, including the critical 10-inch Phillips
66 high pressure pipeline crossing at the intersection of 1st Avenue North and Highway 87. The project
also involved close coordination with the Montana Department of Transportation (MDT) for permitting
the new water main in their right-of-way as well as designing the water main alignment to accommodate
the future reconstruction of 1st Avenue North.