Here’s a ‘inside look’ – with perhaps the very last photos taken inside – the Powell Butte Reservoir #2 Project …
As the Powell Butte Reservoir #2 Project nears completion, the top of the tank is in place. The dark patches are an insulation material.
Story and photos by David F. Ashton
Contractors building the second underground 50-million gallon reservoir for the Portland Water Bureau (PWB) at Powell Butte Nature Park in outer East Portland made good progress during the summer months. However, the unseasonably heavy downpours recently slowed them down somewhat.
This construction “access hole” to the western water cell is now sealed; soon the tank will be air pressure and water tested.
As he drove up to the worksite on the afternoon of September 11, PWB Public Information Manager Tim Hall said that the addition of the 50-million gallon reservoir was necessary because of the mandate to disconnect the three open reservoirs at Mt. Tabor, and one on the west side in Washington Park.
After donning safety gear, PWB Engineer Tech Kareem Hill led the tour of the western 25-million gallon “cell” – water tank – before it was sealed up.
PWB Engineer Tech Kareem Hill and PWB Public Information Manager Tim Hall stand next to the floor drain, into which water will flow from the cell into the drinking water system.
Water-drain valves, such as this one, will be opened and closed by remote actuators atop the reservoir, allowing millions of water to flow into the system across the City.
“This is the last time anyone without ‘Confined Space Clearance’ will be able to walk into this cell,” observed Hall. He pointed to a long concrete stairway on the opposite side of the cell that workers will use after the last wall is sealed up.
“We’re doing air pressure testing of the east cell right now,” Hill told East Portland News while walking down the slope to into the western cell. “They seal off the cell, and pump in air; by measuring the pressure drop, they know if there is leakage.”
Workers prepare to hang a “wash down” system pipe from the ceiling of the cell.
In the cavernous western cell, workers piece together water pipe, lying on the floor of the reservoir section.
“That is ‘wash down’ piping,” Hill explained. “In a way it’s kind of like a fire sprinkler system; it’s used so we can pump water when we’re washing down the cell.”
This worker is patching imperfections in the concrete columns, making sure the surfaces are absolutely smooth.
Inch by inch, crew members inspect the ceiling, walls, floors, and columns, looking for imperfections in the cast concrete – and then fill each one they find.
Other workers were working on high lifts and, at floor level, inspecting every inch of the concrete, with spackle knives in hand.
“Those workers are looking for small pits and holes, and patching them,” Hill said.
Having a smooth, sealed surface minimizes wash-down maintenance, Hall said. “Compared open reservoirs that must be cleaned every six months, the covered reservoirs only need cleaning once every five years.”
On that day, the project was about 80% completed, Hill said; “It may be online by December.”
Work on the Powell Butte Interpretative Center building nears completion.
Interpretative Center opening delayed
“We generally have good weather through the end of September,” commented Hall, as the tour continued at the Powell Butte Interpretative Center building – but not this year!
The mural was installed, the huge slide-up glass doors were in place, and workers were finishing the interior and exterior of the new building.
It was a sunny day during this visit – but heavy rains later in September slowed progress in completing the new Interpretative Center.
Here’s a sneak peek at the photo-realistic mural that covers the Interpretative Center’s interior eastern wall.
“We had planned to open the Interpretative Center the first of October, but now, because of the heavy rains in later September, it looks as if that may be delayed until mid-November,” Hall revealed.
Landscaping work will continue around the Interpretative Center, according to Hall, and should be soon completed. “After the testing of the reservoir has been completed, contractors will begin to cover it with soil that was removed during construction. We still expect the project to be completed in the spring of 2014.”
Tim Hall speaks October 8
If you’re interested in hearing Tim Hall speak, come to the Midway Business Association meeting on October at 11:45 a.m. Guests are welcome; the meeting is free, but you pay for your own lunch. It’s at Bill Dayton’s PIZZA BARON Restaurant on SE 122nd Ave., just south of Division St. For more information, see their website: CLICK HERE.
© 2013 David F. Ashton ~ East Portland News