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Portland ratifies emergency contract for US 181 wastewater reroute after engineers warn of likely failure
Summary
The City Council ratified emergency purchases Nov. 19 to install a new, cased wastewater line under US 181 after engineers found tuberculation and a section likely beginning to fail in a 15-inch gravity line that carries an estimated 70–75% of the city’s wastewater. Construction is slated to begin Dec. 2.
Portland’s City Council voted Nov. 19 to ratify emergency purchase orders totaling up to $1,608,090 for engineering and construction to install a parallel, cased wastewater line beneath U.S. 181 after staff reported signs the existing pipe was failing.
The council approved a not-to-exceed $116,600 emergency engineering purchase with LJA Engineering and a not-to-exceed $1,491,490 construction agreement with IPQ Construction LLC to install a 15-inch PVC wastewater pipe inside a 24-inch steel casing using jack-and-bore methods, and then abandon the existing line in place. “Currently Portland has a 15 inches gravity line that goes underneath ... and it conveys roughly 70 to 75% of the city's wastewater,” Dr. Banks told the council, summarizing the condition assessment.
City staff and LJA engineers said video assessments found extensive tuberculation, multiple pipe materials and a section that appeared to be moving and possibly collapsing, prompting emergency procurement. LJA’s engineer explained the chosen installation method requires a rigid steel casing that is welded and jacked through the ground; plastic casing would not be compatible with the jack-and-bore approach. LJA said permitting from TxDOT is already authorized and mobilization is scheduled for Dec. 2, with boring to begin Dec. 9 and a 70-day contract window.
The project will require traffic impacts and street closures near West Broadway and the US 181 exits. Staff advised the work will use the city’s utility fund reserves; staff also said they will publish informational graphics and a project overview video on the Public Works project page and on social channels. When asked what a catastrophic collapse of the old pipe would mean, Dr. Banks said a collapse could cause surface instability and create “extremely difficult conditions with rerouting the wastewater,” and that staff have contingency plans though exact outcomes are uncertain.
Council members asked technical questions about tie-ins, flow and the abandonment approach; Dr. Banks said the abandoned pipe will be stabilized and “plugged and pumped full of, flowable fill” to remove cavities. LJA said tie-ins will likely use a doghouse manhole (one pipe in, one pipe out) that should convey the expected flow.
Mayor Pro Tem Green moved to ratify the city manager’s emergency approvals; the motion was seconded and the council approved the ratification. The council did not provide a roll-call tally in the public portion of the transcript.
