A Temperature-Adjusted Approach to Verifying Rainfall Dependent Inflow Volumes in Gwinnett County, GA

摘要

Locating and eliminating rainfall dependent inflow and infiltration (RDM) from collection systems continues to be a major concern for utilities due to its impact on system capacity and potentially causing sanitary sewer overflows (SSO). Flow monitoring has been the main tool for gathering flow data and estimating RDM quantities. Based on these results, inspection programs are developed to address monitoring areas with the largest RDM contributions. However, obtaining sufficient data from the flow meter network to identify small areas for field inspection can be time consuming and demanding on resources. This paper discusses the use of wastewater temperature changes to identify and estimate amounts of rainfall dependent inflow (RDI) in the 24 hours following a rainfall event. The findings of this case study show that temperature adjusted RDI estimates correlate to those obtained using the traditional approach. This suggests the potential for developing and deploying less expensive temperature probes within the wastewater collection system to supplement traditional flow monitoring programs thereby improving efficiency and cost-effectiveness of the monitoring program.