PROJECT NAME: Will Crandall Reservoir Project - Construction Blog
The Crandall reservoir and its components are projected to be completed in spring 2014. Hillsboro Water will be keeping this project blog during that time so you can follow the construction process via words and pictures. Updates will occur about once per week, or whenever significant or interesting events happen at the site. Please feel free to e-mail us with any comments about the postings or the Crandall project.
Reservoir
DN Tanks is on the second week of wrapping the exterior of the reservoir with the 1st of 3 layers of 3/8” galvanized cable. A total of 80 miles of cable will be installed, with a layer of shotcrete (concrete slurry) sprayed over each layer, before the process is complete. Cable is stressed to 14,950 pounds to provide stability to the structure, primarily during earthquakes. The wrapping process is scheduled to be complete by the end of May.
Pump Station
The framing of the roof section is almost complete and the metal roof is soon to be installed. Interior electrical conduit and plumbing are being installed, and an 800kW back-up generator and switch gear have been installed for emergency operation. Interior painting and dry wall are next.
On March 21st the contractor poured the final roof section on the structure. All concrete has now been completed, minus the main roof hatch and a couple of roof vents. The contractor is in the process of removing the interior roof shoring scaffolding and patching various holes and imperfections inside the tank. DYK, the subcontractor who will complete the exterior walls of the reservoir by wrapping them with multiple layers of tension cable and shotcrete, will mobilize onsite the week of April 15th to begin work.
The block wall mason has completed construction of the interior and exterior walls for the pump station and is in the process of mobilizing his material and equipment offsite. This week roof trusses will be delivered and work will begin on the building of the roof.
Last week, subcontractor DYK completed tendon pre-stressing in the walls of the reservoir. General Contractor, Ward Henshaw, is finalizing rebar placement and will pour the third of four roof slabs on March 14, 2013. The final roof pour will take place next week, weather permitting.
Masonry work is in full swing, especially considering the warmer, drier weather this month. Ward Henshaw lowered the water discharge pumps in place on March 13th, along with large piping pieces, prior to the structure being enclosed and only allowing limited access. Walls will be erected and completed in two weeks, then the roof trusses will be placed for roof construction.
The last of 18 reservoir wall sections were poured last week, along with the remaining interior concrete columns.
Earlier in the month, two of the four roof sections (north half) were poured. Crews are now moving shoring scaffolding and building forms for the south roof sections, with a concrete pour scheduled for the week of March 11th.
The floor slab was poured earlier this month and is two feet thick. Now the contractor is preparing for the start of masonry work to construct the exterior walls for the building. The block wall will be completed in approximately three weeks. After that, roof joists will be placed, and the roof will be installed.
Aerial 2-15-13
The Evergreen School STEM Club revisited the Crandall Reservoir and checked out the walls and roof that have been poured since their last visit. Taylor Smith, a reporter from the Oregonian, also accompanied the group and wrote an article about the partnership: http://bit.ly/Zgf7re
Seventeen of the reservoir's 18 wall panels have been poured, and 62 of the 88 supporting columns have been poured. The contractor is now in the process of erecting roof shoring on the north half of the structure. There will be a total of four pie-shaped concrete pours to complete the roof of the reservoir.
The contractor finished the 24” ductile iron fill pipeline between the JWC 66” transmission pipeline tap and the pump station. The aggregate subgrade under the pump station has been brought up to grade. Now the contractor will begin installing utility conduit that will be used for housing several electrical and communication cables that will service the building. Once the conduit is in place, the 24” floor slab will be poured.
Construction update on two elements of the Crandall Reservoir Site:
Ward Henshaw completed the last of nine reservoir floor slabs on November 27th, and is currently working on wall construction. They have six wall sections poured and will pour four more this week. The crews have also begun to pour the interior columns that will support the roof. As of Friday, December 7, they have poured eight columns and anticipate pouring a minimum of four columns each work day (There are 88 columns total).
Subgrade piping has been installed at the pump station, including the 24” inlet and outlet piping between the reservoir and pump station. Once the piping is installed, it is encased in concrete beneth the pump station floor. Other yard piping that has been completed includes the inlet fill piping with flow meter inlet and outlet vault and assembly.
Evergreen Middle School STEM Club Visits Resevoir Site
Students, interested in exploring future careers in the sciences, visited the newly-poured bottom of the Crandall Reservoir and felt the still-cooling concrete.
Concrete Effort to form Tank Bottom
Today, Ward Henshaw completed the first of nine concrete pours for the base slab of the Crandall Reservoir. This pour used approximately 250 cubic yards of concrete. The total thickness of the base slab is 24 inches.”
Rock and Roll!
The subcontractor, Landis and Landis, has placed base aggregate and just finished installation of the underdrain piping and drain aggregate. Ward Henshaw is soon to begin forming for the concrete reservoir slab.
Excavation for the pump station piping and pump cans will begin next week.
That's one big hole in the ground!
Excavation for the reservoir is essentially complete! This is the bottom! From here on, the contractor will be going up. Beginning next week, the contractor will be placing geotextile fabric and base rock for the tank. The cement deep soil mixing (CDSM) matrix that will support the reservoir can easily be seen in these photos.
Foundation core sampling completed
The cement deep soil mixing (CDSM) equipment can be seen at the top of the aerial photo dated July 12. The CDSM contractor has been drilling core samples of the soil cement foundation for testing. Now that the coring is nearly complete and the soil cement improvements have been accepted, the subcontractor performing that work is dismantling their equipment and removing it this week. The final excavation of the reservoir to the bottom elevation by the civil construction subcontractor can proceed.
Deep soil mixing finished. Excavation accelerated.
The deep soil cement mixing has been completed. The earthwork contractor is on an aggressive schedule to excavate the reservoir foundation. The contractor is trying to get back on the original timeline after forced scheduling setbacks due to an extraordinarily wet spring.
Deep soil mixing nears completion.
The deep soil cement mixing is nearly complete at Crandall Reservoir site. The subcontractor performing the work anticipates completion of the work next week.
What's up next? The earthwork subcontractor will begin excavation to the bottom elevation of the reservoir foundation later this week.
Construction Variance Notice
Ward Henshaw, Project Contractor, received a variance allowing extended construction hours (6:00 a.m.- 10:30 p.m., M - Sat), in order to expediate the deep soil mixing portion of the project. The work variance will begin June 4th and will last for approximately two months.
Equipment on site. Test mixing to begin. Noise issue addressed
Raito Inc. has moved onto the Crandall Reservoir site with a crane and the deep soil mixing equipment. They plan to do some test mixing over the next month during normal working hours.
Also, trucks bringing equipment to the site at 2 a.m. the other morning disrupted the sleeping neighborhood. Hillsboro Water staff has asked the contractor to make sure that future equipment deliveries arrive during normal business hours to minimize noise impacts on the community.
Crandall Reservoir site makes water connection - requires work in Evergreen roadway
The contractor is connecting to the waterline this week, which requires work in Evergreen Roadway. The road will be open, but some traffic delays are expected.
Initial work on Will Crandall Reservoir site hampered by weather
Ward Henshaw has moved some equipment onto the Crandall site, and is busy creating the roads and construction area within the site. Progress is slow-going due to the overly wet March weather, but such is spring in the Pacific Northwest.
March 14, 2012
Application for Exemption for Small Conduit Hydroelectric Facility
The City of Hillsboro Water Department is constructing a new 10 million gallon (MG) potable drinking water tank to increase storage capacity of the municipal water supply. As part of the proposed facility, a hydro-turbine has been designed to capture the excess pressure in the conduit between the 66” transmission pipeline and the tank.
An application for exemption has been submitted to the Federal Energy Regulatory Commission (FERC) for approval.
The application is available below for review.
Ward Henshaw Construction Company moving onto site
Ward Henshaw, project contractor, (PC) will mobilize and begin to move onto the Crandall Reservoir site today. Once there, the first course of action will be to build a noise-mitigating berm around the site.
The PC received a variance that allows up to 90 days of extended construction hours (6:00 - 10:00 p.m., M-Sat), in order to expediate the deep soil mixing portion of the project. The berm, "Hollywood-style" generators and other techniques will be used to mitigate noise on site.
Project Contact Information
Postcards were mailed out to site neighbors with contact phone numbers on them. Hopefully, recipients will put the cards on their refrigerators, or in other handy spots, in case they need to call for information during the course of the project. The numbers are also posted below.
Contacts are:
Contractor (Site Activity Inquiries): 503-519-7760
Hillsboro Water (Project Inquiries): 503-615-6702
Water •150 E Main Street • Hillsboro OR 97123 • (503) 615-6702 • Email