Del Oro Traver District TCP Mitigation Project
Project Update – February 2023
Del Oro is working with its contractor and engineer on the final outstanding items to get approval from the State to bring the water treatment plant online. We thank you for your patience as we work to complete this project.
Below, you can see the carbon filter media being delivered for the treatment vessels:
Project Update – May 2022
The treatment plant is nearing completion, with some electrical work remaining. Del Oro is waiting for PG&E to install its transformer to power the plant, with final inpections and testing to follow. The project has taken longer than anticipated due to long lead times on various components and materials.
The photos below show the site graded with aggregate. The fence has been removed around Well #1 to integrate it into the treatment plant site.
Below, you can see the electrical conduit has been installed to the hydro-pneumatic tank on the left. The picture on the right shows the pad that is ready for the transformer when it’s available.
Project Update – February 2022
During February 2022, the water treatment plant really started coming together toward completion.
In the photo below, you can see most of the site from the perspective of the well head:
Seen below is the completed fence:
And below are three photos showing concrete work completed at the generator pad, chemical building, and the plant driveway:
Project Update – January 2022
During January 2022, the contractor completed the connections at the well head, to and from the treatment vessels (top photo). They also backfilled all of their trenches (bottom photo).
Project Update – December 1, 2021
Many items have been completed, or are nearing completion since the last update.
The piping for the backwash pump is nearly complete (left), and the underground piping for the GAC Vessels has been completed and buried (right):
The emergency generator has been placed on the slab, and the electrical conduit has been set:
Project Update – November 3, 2021
In the past three months, there have been significant delays in the Treatment Plant Project due to permitting and supply chain issues. Please see the updated timeline below. The project is estimated to be completed by the end of 2021.
The GAC Vessel piping was installed in September; shown here with the backflow pump assembly, which is ready to be hooked up:
The chemical building arrived in late October, which will house the chlorine used to disinfect the raw water:
Project Update – July 27, 2021
The GAC Vessel and piping arrived this morning for installation. Please see the updated timeline below for estimated treatment plant completion.
The arrival of the GAC Vessels and the piping:
Offloading the piping for the GAC Vessels:
Offloading the GAC Vessels for installation:
GAC Vessels and piping installed on the cement slab:
Project Update – June 29, 2021
The crew is currently building the backwash tank and expects to complete it by Friday, July 2, 2021.
Project Update – June 4, 2021
This week, crews prepared for and poured the cement pads for the backwash tank ringwall, the chemical room, and the granular activated carbon filters (GACFs) which make up the treatment vessels. They finished the forms, installed rebar, and poured cement. They also re-compacted the generator area in preparation for its cement pad.
Backwash Tank Ringwall:
Chemical Room Pad:
GACF pad:
Generator Pad Re-Compaction:
Project Update – May 28, 2021
After fulfilling the additional permit requirements, crews are back at work on the treatment plant. The county inspection was completed for the ring wall, chemical room, and for the treatment vessel pad. They are currently preparing to pour the cement pads for the generator and for the treatment plant vessels. They plan on puring cement next week. Once poured, the cement will cure for two weeks before placing anything on the pads.
Project Update – April 7, 2021
During the past month, the contractor was informed by Tulare County of additional permit requirements. While awaiting the updated permit, crews have stayed busy installing rebar for the backwash tank wall, and completing that form. Concrete will be poured to form the tank wall when approval is granted.
Preparations are continuing for the concrete pads for the vessels.
Project Update – March 5, 2021
The storm drain pond was completed this week, with riprap placed around the inlets. The old pipe has been disconnected to Well 1, which is no longer in use. Preparations are being made to start pouring concrete pads, including leveling the lot and fabricating rebar.
Project Update – February 26, 2021
The construction crew worked to keep the street clean while grading the storm drain pond this week, as shown in the following pictures:
Project Update – February 11, 2021
The construction crew cleaned and leveled the storm drain pond this week, as shown in the following pictures:
In addition, trenching was done, and electrical conduit was installed:
Finally, forms are going up to pour the walls for the backwash tank:
Project Update – January 26, 2021
The construction crew broke ground on the Traver TCP Treatment Plant the week of January 11, 2021. Because the treatment plant requires a new backwash tank, crews first needed to bypass and abandon the mainline currently running through the site for that tank. To avoid interruption of service, the bypass was hot tapped into the existing lines.
Here, personnel are shown tapping into the existing line (bottom of photo 1), and connecting the new bypass into the existing line running parallel to the street (right side of photo 2).
Summary
The synthetic organic chemical and carcinogen 1,2,3 Trichloropropane (TCP) was detected in Well 3 at levels exceeding the maximum contaminant level (MCL). There are only two active groundwater wells available to supply the surrounding community. Well 3 provides a capacity of 550 gallons per minute to the area. Provost & Pritchard Consulting Group and Dawson-Mauldin Construction will install two Granular Activated Carbon (GAC) Vessels along with the accompanying structures, apparatuses, and instrumentation at the well site to remove TCP from the water. The GAC vessels are essentially large-scale versions of a Brita Filter. Additionally, the nitrate concentration will be monitored due to high nitrate levels found in the area. Construction began in January 2021, with the goal to start treatment in June 2021.
Timeline (as of 1/13/21 – subject to change)
Notice to Proceed – December 2020
Submittals and Review – December 2020/January 2021
Mobilization/Clearing – January-May 2021
Construction – January 2021
Filter Media Installation – May 2021 July 2021 (as of 6/29/21) December 2021 (As of 11/3/21)
Start-up – May/June 2021 August 2021 (as of 6/29/21) December 2021 (As of 11/3/21)
Demobilization – May/June 2021 August 2021 (as of 6/29/21) December 2021 (As of 11/3/21)
Treatment Train
Well
•Treatment location at Well 3
GAC Vessels
•Manufactured by AqueoUSVets
•Two GAC filters for redundancy and backwash
Disinfection
•Chlorine injection by chemical dosing pump
Analyzers
•Chlorine Residual Analyzer
•Nitrate Analyzer
Distribution System
•Treated water is distributed through the existing system after treatment
•Backwash water will be sent to a nearby county stormwater basin
AqueoUSVets GAC Vessel Example (Traver District’s configuration will differ):
Rendering of the GAC Vessels at the Traver TCP Treatment Plant:
Overhead plan rendering of the Traver TCP Treatment Plant:
Update – 2015 Meter Exchange Project
Installation of meters in Traver is complete as of December 2017. Customers billed flat rate will be transitioning to metered rates for their February 2018 bills. Since flat rate service is billed in advance, flat rate customers will not receive a January 2018 bill as metered service is billed in arrears. Please see the letter that was sent to flat rate customers with the December 2017 bills for additional information:
Letter re: Change to Metered Service
2015 Meter Exchange Project
Flat Rate customers will be gradually transitioned to meters no later than the end of 2016.
2015 Emergency Standby Well Project– Last Update: 10/16/15
One of Del Oro Water Company’s first priorities for our Traver District customers is to undertake necessary improvements to Well #2 (the standby well). Well #2 has a water-level deficiency due to the water table having dropped to below the level of the well’s pump settings. It appears that the over drafting of the basin in that area has contributed to the significant draw down of the water table during the severe drought we are all experiencing.
In order to prevent future water outages and maintain the health and safety of the water system, Del Oro Water Company is immediately undertaking a depth increase of Well #2, as well as assessing and addressing any other conditions with the well which may be found. The total cost of the project is estimated, at this time, to be approximately $15,000 to $20,000.
