City of Austin Performance Report 2014-15
Number of Reportable Wastewater Overflows Per 100 Miles of Wastewater Lines Per Year
A reportable Sanitary Sewer Overflow (SSO) is an overflow that originates from/or is caused by city-owned sewer components, and reaches storm drains or waterways. Sewage that reaches storm drains or waterways could contaminate water wells with disease causing agents and could result in other health and environmental hazards.
This measure is an important indicator of the effectiveness of the operation and maintenance of the wastewater collection system. A low number of SSOs indicate a higher functioning wastewater collection system, better repair practices, more effective cleaning and remote television viewing (TV) activities, and lowers the potential for enforcement actions by regulatory agencies.
For this calculation, the number of reported sanitary sewer overflows is divided by the miles of wastewater main.
FY 2014-15 Results
The goal for this measure is less than three (3). The result of 3.04 was 0.04 above the goal. As shown in the graph below, the measure increased in FY 2014-15 due to the historic flooding events near Memorial Day 2015. Removing the effects of the historic storm, the measure would have been below the goal.
Assessment of Results
The number of reported overflows increased due to the historic flooding events near Memorial Day 2015. To achieve the goal, it will require the continuation of the Clean and TV Program, the continuation of Capital Improvement Program (CIP) projects to rehabilitate and replace aging infrastructure, and the continuation of the Austin Water SSO response procedures to reduce the impact of sewer main backups and the volume of overflows. The use of contract construction services has expedited the complex repair of defective wastewater lines. The long-term review of this measure indicates the collection system and emergency response procedures have made the Austin Water (AW) service area safer from the effects of wastewater spills.
AW remains committed to managing reported wastewater overflows. To this end, AW continues to monitor and track this measure to proactively reduce SSO. In addition to the Clean and TV Program, CIP projects, and SSO response procedures, AW is building a system-wide condition assessment database for all wastewater mains using TV inspection software and industry-standard condition ratings. The asset management plan will direct limited resources toward the highest priority mains for rehabilitation or replacement and can be expected to reduce the number of reportable SSO, including repeat SSO as it is implemented.
For more information contact Kevin Koeller, P.E., Division Manager, at (512) 972-2055.