For Utilities Commission Meeting [October 16, 2018]
TO: Honorable Chairperson and Commission
APPROVAL: Thomas J. Crowley, P.E., Utilities Manager
FROM: Susanne Wilcox, Administrative Analyst
Title
Recommend the City Council approve the Wastewater Treatment Plant Digester No. 1 Completion Project in the Amount of $348,836.
(ACTION)
Body
BACKGROUND:
The City of Rialto has two Digesters located at the Wastewater Treatment Plant (WWTP), Digesters No. 1 and No. 2, which process solids that come from the primary and secondary treatment process. During the processing of wastewater, the solids are heated and mixed for further break down in the Digesters. The Digesters are a critical part of the treatment process, and having two Digesters in operation provides redundancy and reliability for the treatment process at the WWTP. However, Digester No. 1 has been out of service for many years, and it is important to complete modifications to the Digester No. 1 in order to return it to service. Digester No. 2 is in service and is operational but plans are in place to take it out of service for repairs and maintenance in June of 2019.
Digester No 1 was constructed in 1965 and was taken out of service in 2013 to add a Dystor cover by Evoqua Water Technologies (Evoqua), which was subsequently installed in July 2016. However, the Dystor cover has not been commissioned due to technical and operational issues. In order to safely take Digester No. 2 out of service, Digester No. 1 needs a few more modifications in order to bring it back into service.
ANALYSIS/DISCUSSION:
Staff representing the City, West Yost, Rialto Water Services and Veolia have met several times to develop a list of tasks that would need to be completed in order to bring Digester No. 1 into service. Below are the tasks:
1. Realignment of cables on Digester No. 1. Dystor cover cables have moved out of alignment through high winds in the area. The cables need to be moved into the proper position and installation of final air and gas lines must be completed.
2. Perform leak test of Digester No. 1 Dystor cover.
3. Replace and recalibrate the instrumentation and monitoring devises for temperature, pressure, and flow for Digester No. 1.
4. Integration of instrumentation and monitoring devices to the existing treatment plant Supervisory Control and Data Acquisition (SCADA) system.
5. Provide and install an emergency generator for the inflation of the Dystor covers for Digester No. 1 and 2 and operation of the gas flare.
6. Installation of bypass line for the motorized operated valve that directs flow to Digester No. 1 and 2.
Evoqua has indicated that they are available the week of December 17, 2018, to do their portion of the work required. All other work is scheduled to be completed by the end of February 2019.
FINANCIAL IMPACT:
Operating Budget Impact
Once the tasks have been completed, operating costs for the Digester No. 1 will continue to be absorbed by the Utility Authority through the Concession Agreement.
Capital Improvement Budget Impact
Sufficient budget is available in Sewer Fund Account No. 660-500-7150-3001 in the amount of $348,836. The following table summarizes the project costs:
RECOMMENDATION:
Staff requests that the Utility Commission recommends the City Council Approve Wastewater Treatment Plant Digester No. 1 Completion Project in the amount of $348,836.