Abstract
Population growth brings capacity issues, climate change brings increased frequency and intensity of storm events, and ongoing system blockages from FOG result in overflow conditions that impact our communities and the environment. Municipalities are subject to ever-tightening regulatory oversight where high cost consent decrees for sanitary sewer overflows (SSOs) and combined sewer overflows (CSOs) are becoming the norm. The typical response is expensive capital upgrades to collection system infrastructure and high frequency cleaning of collection system segments on a schedule. Faced with uncertainty, municipalities are staring down the prospects of significant infrastructure investments and billion-dollar consent decrees to protect residential property, local businesses and waterways -- without a significant increase in resources. Despite the potential penalties and the prospect of massive capital projects, the benefits they may produce are decades in the making and consume billions of dollars of municipal revenue. It is imperative, then, that we begin to understand the real-time operation of our existing collection system infrastructure to maximize utility, minimize costs and target investments to the appropriate and highest risk areas. For more than 500 sewers around North America, the solution involves innovative turbo charging of their collection system engine to take an aggressive stance on risk management. A data-driven early warning system designed combines a real-time view of the sewer and stormwater networks, weather and storm data and real time notifications allowing them to be proactive in responding to conditions and detecting emergencies before an overflow. Those who attend 'Turbocharged Engines' will learn how agencies of varying size are using real-time sewer monitoring technology to provide actionable information in order to protect the environment, safeguard public health and optimize investments in maintenance and capital improvements. Many collection systems adhere to the EPA's comprehensive capacity assurance, management, operations and maintenance (CMOM) programs to prevent CSOs and SSOs. Such measures include backup pumps, frequent cleaning in high-risk areas, capital projects and flow reduction measures that maintain the pipes at their design capacity. While these programs can be effective, they often do not allow utility staff to be proactive – particularly in the face of rapidly evolving events. To provide that next level of understanding, control and response, three cities in Texas turbocharged their sewer intelligence with real-time visibility into the status of their underground infrastructure. These municipalities deployed a network of SmartCover systems to provide real-time sewer level and trend analysis information to a centralized, online dashboard and mobile app. Designed with the unique challenges of a collection system in mind, the technology transmits data from a sensor in the manhole to a satellite in the sky to relay reliable sewer information throughout all conditions – a particular benefit in places like Texas where weather events can often disrupt terrestrial communications. The patented sensors are purpose-built to withstand the harsh conditions in sewer systems and can be installed and serviced without confined space entry. SmartCover provided each utility with an event management platform with localized weather data from the National Oceanic and Atmospheric Administration (NOAA) to rapidly respond to issues before they become environmental, public health and financial emergencies. This system architecture has revolutionized the utility's response, allowing changes in conditions to be monitored in real-time, while reducing the uncertainty around the conditions in the network. Knowing the level trends in the sewers has helped the utilities schedule maintenance when and where it is needed most, and more importantly has been critical in preventing overflow events. SILENT SENTRIES PROTECT ENVIRONMENT The City of San Marcos, TX, treasures the San Marcos River, a spring-fed river winding 75 miles providing a critical habitat for eight endangered species. Further, the region is of significant archaeological interest as one of the oldest continuously inhabited places in North America. Given the river's rich history and central role in the city, its protection is a primary focus. Yet, extreme weather events are making this increasingly difficult. Solution: To preserve the local waterways during extreme weather events, the city installed 10 SmartCover monitors in high risk spots and outflows. Results: Automatic advance notification of blockages has helped the city mitigate SSOs and monitor and report on CSOs, adhering to the Texas Pollutant Discharge Elimination System Small Municipal Separate Storm Sewer (MS4) requirements. SSO MITIGATION SEES IMMEDIATE ROI Heavy rain events contribute to sewer overflows in the City of Arlington, TX, damaging property, the environment and impacting public health. Solution: Installation of 10 SmartCover sensors and rain monitors to measure flow in typical sewer trouble spots. This event-driven system allows staff to react to any blockages and other potential overflow conditions before wastewater backs up into homes and businesses or overflows the system. Results: In the first few months, the City of Arlington was notified of three alarms that helped avoid sanitary sewer overflows-- more than paying for the systems in a short period of time. After a presentation to City Council, the initial deployment was expanded to 60 SmartCover units using NOAA rain data. CLEANING PROGRAM OPTIMIZATION RESULTS IN SAVING 95% San Antonio Water System was facing an EPA Consent Decree with an estimated cost of $1.2 billion. SAWS adopted the EPA's CMOM guidelines and instituted high frequency cleaning for their 110,000 manholes and pipeline segments. Effectively this meant SAWS established a program of cleaning high risk pipes with potential for overflows, and instituted routine cleanings at monthly, bi-monthly, quarterly, semi-annual and annual frequencies. As conscientious sewer operators, SAWS identified 200 high risk sites for regular monthly cleanings – whether the pipes needed cleaning or not. While prudent, the logistics, labor and equipment costs to maintain this level of effort was staggering. Solution: SAWS deployed 200 SmartCover sensors to collect data. SAWS effectively transitioned from a routine, calendar-based cleaning system, to a prescriptive 'as needed' cleaning program when automatically notified of blockages. Results: SAWS has experienced a 95% reduction in cleaning, ZERO SSO incidence and 216 SSO 'saves.' Nearly 1,300 cleanings were scheduled, but only 65 cleanings were identified and performed -- an estimated $1 million in savings. By trusting automated data analysis, the optimized maintenance schedule has led to significant positive benefits for the operator, environment, and communities served. Not only is SAWS effectively reducing wear and tear on pipelines from the routine cleaning, it's also allowing their operators to refocus on other pressing activities. CONCLUSION Operators in the City of San Marcos, City of Arlington and City of San Antonio have successfully turbocharged their collection systems with innovative technology. All cities reported reduced overflows and costs. These 24/7, silent sentries have brought peace of mind knowing sewers are being monitored, data is automatically analyzed and plenty of advance notice will be given.
The following conference paper was presented at Collection Systems 2021: A Virtual Event, March 23-25, 2021.
Author(s)P. Neofotistos1; A. Duron2; M. Mosier3
Author affiliation(s)SmartCover1; San Antonio Water System2;
SourceProceedings of the Water Environment Federation
Document typeConference Paper
Print publication date Mar 2021
DOI10.2175/193864718825157910
Volume / Issue
Content sourceCollection Systems Conference
Copyright2021
Word count8