Session 06B: Facility Operations
1:15pm - 2:00pm
Creating an Electronic O&M Manual for Pierce County’s Chambers Creek WWTP
1Brown and Caldwell; 2Pierce County Planning and Public Works; , ,
Plant operations and maintenance manuals are often voluminous, stored in cumbersome hard copy binders, or saved as a multitude of electronic files which must be separately opened and browsed, and often neglected because they are difficult to update contemporaneously.
The Pierce County Project Team collaborated to create an IT solution for the operation and maintenance documentation needs of the recent Chambers Creek Regional Wastewater Treatment Plant Expansion (CCRWWTP). The team envisioned and executed an online electronic operations and maintenance (eO&M) manual. The eO&M consolidates and integrates all content related to the plant expansion, including engineer’s technical operations manuals, original equipment manufacturer (OEM) O&M manuals, record drawings, SCADA control modules, emergency response protocols, and plant related ancillary libraries. The eO&M is hosted on Amazon Web Services (AWS) and utilizes the OMS-Connect software platform. The CCRWWTP eO&M was structured as an evolving, living document designed to be appended by the County.
This presentation will provide an overview and online demonstration of the Pierce County CCRWWTP eO&M, discussing functionality, enhanced user experience, lessons learned, and tips and tricks for future eO&M authors. Modernizing O&M Manuals is important to sustained utility operations in the information age.
2:00pm - 2:45pm
CFD Modeling for Trickling Filter/Activated Sludge Secondary Clarifier Optimization
1Hazen and Sawyer; 2City of Salem, OR; ,
Clarifier CFD modeling is relatively common, however, most secondary clarifier studies are conducted in an activated sludge application. Trickling filter effluent (TFE) has different characteristics than conventional activated sludge. To the knowledge of the authors, a similar case study to the one presented here for the evaluation and optimization of TF clarifiers has not been presented before. This study is unique and presents a detailed analysis of settling and flocculation properties of TFE and the application of secondary clarifier CFD modeling to establish clarifier capacity and identify optimization strategies.
The City of Salem’s Willow Lake Water Pollution Control Facility (WLWPCF) has a permitted capacity of 35-mgd average dry and 155-mgd design peak wet weather flow. The City budgeted for clarifier rehabilitation due to ageing mechanical equipment but desired to understand clarifier capacity limitations and evaluate whether modifications could expand existing available capacity.
Hazen conducted stress tests and developed calibrated CFD models for the secondary clarifiers. Model calibration was based on an extensive clarifier testing protocol to simulate peak clarifier loadings, characterize sludge settleability and flocculation properties, and evaluate performance. This work included field testing, zone settling, flocculation and dispersed solids testing.
After development of the CFD models, the clarifiers were evaluated to determine available capacity with the current geometry and mechanism type. Optimization strategies such as the addition of energy dissipating inlet wells, modifications to the flocculation well sizing, and the addition of baffling were evaluated. The City used these results to tailor capital planning for clarifier rehab projects and re-evaluate wet weather capacity and operating strategies at the WLWPCF. Based this work, improvements were identified to potentially expand the combined clarifier peak flow capacity from approximately 105 mgd to over 140 mgd.