Tuesday 3:00 PM
[Presentation PDF]

Room: Capitol III

Planning for System Operations During Adverse Conditions

System planning for sewer systems usually involves sizing infrastructure to handle dry-weather and wet-weather flows for normal operating conditions. However, for critical infrastructure, especially major pump station-force main systems, consideration should also be given to system operations during adverse conditions, when portions of the collection system may require scheduled or unscheduled servicing or be damaged. Detailed planning for system operations during adverse conditions provides utilities with tools for addressing these situations efficiently and cost-effectively. Orange County Sanitation District (OCSD)'s hydraulic assessment of the manifolded Newport Force Main Network (NFMN) showcases an approach for detailed planning of system operations under adverse conditions. Running along the Pacific Coast Highway, the NFMN consists of approximately 44,500 LF of parallel, interconnected pipelines varying in size from 22 to 36 inches in diameter. This hydraulic assessment provided OCSD with a blueprint for meeting its desired LOS, even with portions of the NFMN system out-of-service or operating at reduced capacity. The approach includes the following key features: (1) workshop-based selection of specific ___boundary___ scenarios, which set reasonable limits on system performance conditions for which OCSD would be responsible; (2) use of OCSD's detailed InfoWorks model of the NFMN to determine capacity limitations for these scenarios, resulting impacts on the upstream sewer systems, and required supplemental pumping rates; and, (3) development of SOPs to manage system operations for critical NMFN assets during adverse conditions.

Moderator:  Lou Storino


Gunilla Goulding - Malcolm Pirnie, Inc./ ARCADIS

Gunilla Goulding, a Senior Project Engineer with Malcolm Pirnie, Inc/ARCADIS. in Schaumburg, Illinois, has more than 13 years of experience in combined sewer overflow (CSO) and sanitary sewer overflow (SSO) planning and analysis, hydrologic and hydraulic modeling, and sewer monitoring data assessment. Her expertise in collection system modeling has supported sewer utilities in developing master plans, evaluating infiltration/inflow impacts and solutions, assessing CSO and SSO control options, and answering regulatory actions.