BACKGROUND
As the third largest municipal utility in California, the San Francisco Public Utilities Commission (SFPUC) provides three essential utility services: water, wastewater and electric power. Its stated mission is “to provide our customers with high quality, efficient and reliable water, power, and sewer services in a manner that is inclusive of environmental and community interests, and that sustains the resources entrusted to our care.”
The extensive wastewater system managed by the SFPUC collects, conveys, and provides secondary treatment to combined sewage flows – stormwater and sewage – within the City and County of San Francisco before discharging it into the San Francisco Bay and the Pacific Ocean. The SFPUC’s Combined Sewer System is comprised of 1,010 miles of sewer pipes, a wet weather transport/storage system and three treatment plants taking in flows from roof drains, domestic sewage and street runoff.
CHALLENGE
Utilities face growing challenges. Those challenges include environmental compliance, climate variability, aging infrastructure networks, financial shortages, and labor efficiencies are uppermost concerns of water, wastewater and stormwater utilities. Mitigating those concerns is accomplished through incorporating technology that improves productivity, quality, safety, reliability and sustainability.
As with many utilities, SFPUC is tasked with monitoring for a variety of factors. Its environmental monitoring program is driven by regulatory compliance, calibration of the city-wide hydraulic and hydrologic (H&H) model, establishment of repair and rehabilitation prioritization and real-time operational decision support. Other factors include early warning from collection system to plant operations, pre-development monitoring for upgrades and forensic analysis of wet-weather and storm effects.
SOLUTION
Trimble's Telog family of Internet of Things (IoT) wireless battery-powered data recorders enable utilities to collect, monitor and manage water and environmental data collected from the field, and access the information via the web and mobile applications for iPhones, iPads and Android devices.
Trimble Telog Enterprise software securely captures and centrally stores remote monitoring data, processes alarms and alerts, and allows data access for third-party software.
Its alarm-based messaging activates when rain or flow has exceeded a critical threshold, assists in the decision-making process and tracks correlation between multiple data sets or trends in real time, supporting environmental compliance and reporting.
SFPUC uses Trimble wireless monitoring technology as a tool in its toolbox because it’s a battery-powered system and for its speed of deployment, open architecture, rapid scalability and minimal engineering, notes Anton Loof, senior application engineer for Ponton Industries, which provides solutions in flow, level, temperature, pressure and process control requirements.
Other advantages it offers include, using a radio network managed by Verizon and Spring. Additionally, the solution provided a lower total cost of ownership in contrast to traditional SCADA technologies.
IMPLEMENTATION
The project scope and implementation of SFPUC’s environmental monitoring program encompasses a vast network of sensors and wireless recorders, including a rain gauge network, combined sewer discharge (CSD) level monitoring, flow model calibration, and saltwater intrusion detection.
Flow model calibration, CSD detection and volume estimation is used for mass balance, continuous updating of the baseline model, capital improvements program planning, and real-time decision support.
Trimble Telog IoT remote monitoring connects to third-party flow, rain and water quality sensors. The monitoring network encompasses more than 120 Trimble Telog wireless recorders. Telog Enterprise stores and analyzes data, provides alerts and alarming, and integrates with third-party distributed control systems and systems of record software.
The Trimble Telog recorders connect to a variety of sensors, including the HACH Doppler Sewer Flow, Telog ultrasonic water level, and the HACH radar sewer flow. Other sensors include conductivity, flap gate position, H2S gas concentration, and redundant rain gauges.
The telemetry platform Trimble Telog recorders include the new Telog Ru-35, which provides real-time monitoring and alarming of flow, pressure and water quality instruments and sensors found in the harsh environments of sewers and underground water vaults.
Combined with a Trimble Telog software option, it offers wireless wastewater infrastructure monitoring consistently delivering real-time data and alarms from the field to the desktop or browser. It provides situational awareness of the collection system performance, improves regulatory compliance and enables network modeling calibration.
SFPUC also utilizes Telog Ru-32, a five-channel RTU that can be supplied with one or two pressure sensors and can additionally interface up to two digital inputs (pulse and/or event) and one analog voltage or potentiometer input. Applications include water system pressures, underground water level, mag meters, pressure reducing valves (flow and pressure) and pressure relief valves.
Also part of the system: the Telog R-3303a, which provides flexibility to capture output from a variety of sensors such as pressure, level, flow, pH, temperature and humidity.
BENEFITS
Since incorporating Trimble’s system, the SFPUC has experienced benefits such as the ability to use data to support operational decision-making in real-time, prioritize repairs and rehabilitation, development of calibrated models and an increased knowledge of the system and ability to do forensic analysis, such as pipe flow reversal during wet weather, says Loof.
SFPUC management decided subsequent actions would incorporate real-time web API for the public where appropriate, a low-power radio mesh network such as LTE-M or LoRaWAN, and RTDs to integrate real-time data and rain forecast with a simplified H&H model.
SFPUC derives a desirable return on its investment in Trimble systems, Loof points out. Its managers favor the Telog IoT system because it can be quickly deployed, it integrates with existing systems and software, its communication method is secure, the system was able to adapt well and it provides near real-time data in critical locations.
