Siemens SITRANS User Manual

City of Decatur Implements Siemens SITRANS store IQ for Operational Transparency

Digitalization Application Case Study

Customer Operational Challenges

The City of Decatur Wastewater Treatment plant in Texas includes a polishing pond and effluent discharge basin, both of which can be overcome with algae growth depending on weather and environmental conditions throughout the year. At times, the algae overgrowth would plug areas of these systems and restrict or block the flow from the polishing pond and effluent basin, which sit approximately 300 yards from each other. The 12-inch diameter line from the polishing pond to the effluent basin is buried and not easily accessible. This and the effluent basin’s discharge V-notch weir are both subject to this plugging. The line also includes a shutoff valve, which is another point of clogging that may cause the polishing pond to back-up and potentially overflow. This valve is also used for testing and to ensure proper zero level during annual inspection and calibration of instrumentation per TCEQ (Texas Commission on Environmental Quality) requirements.

Figure 1. Pump truck clearing the discharge line from the Polishing Pond to the Effluent Discharge Basin

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Figure 2. Effluent discharge basin and inlet underground valve handle located in line from the polishing pond

The City of Decatur was already using a HydroRanger 200 with Echomax transducer to monitor the effluent flow from the wastewater treatment plant and record the effluent basin level. The HydroRanger data was recorded so the staff would be aware of any changes that could indicate the potential of a blockage or loss of flow. It’s also worth noting that the HydroRanger 200 was not connected to any SCADA and, as such, required a physical visit to manually read the totalizer and other process information from this instrument. These values were read daily for reporting purposes.

If the effluent flow head measured by the HydroRanger 200 dropped below 5 inches, the staff would typically review the system for the potential of algae blockage in the line from the polishing basin to the effluent discharge basin. Over time, reduction of normal flow from the polishing pond to the effluent basin typically causes the polishing pond to back up, potentially leading to a spill within the confines of the treatment plant. The head level in the effluent basin was monitored as well, and if the HydroRanger 200 indicated a high level, the staff would check the V-notch weir for blockage. High levels in the effluent discharge basin could also cause spills into the environment.

The challenge to the City of Decatur’s operation included the fact that the plant does not have 24-hr manned coverage. If either of these issues arise whether the facililty is manned or unmanned, the possible spills from either the polishing pond or the effluent basin can damage equipment. In addition, there are possible fines from the TCEQ governing body if spills are not found and responded to quickly.

Siemens Digital Solution – SITRANS store IQ

Siemens presented the possible benefits that could be achieved if a digital application such as SITRANS store IQ was implemented for continuous remote monitoring. SITRANS store IQ works with any manufacturer’s instrumentation and allows operators to monitor key data that normally requires physical visits by personnel. Siemens offered a system that could connect, monitor and transmit data to enable more efficient operations. In this case it would automate the manual data gathering process, which included taking readings from the HydroRanger 200 every day at 8:00AM. This information is critical as it is reported to the regulatory agency each month.

So, rather than continue with this manual data collection process, Siemens’ local account manager worked with the customer and the Siemens Engineered Instrumentation Solutions (EIS) team to

Figure 3.a.b.c. Effluent discharge basin V-notch weir for discharge flow measurement and Echomax transducer for level measurement. Note the algae buildup.

deploy SITRANS store IQ. Deploying this digital application included the development of a comprehensive solution to provide remote monitoring of the instruments and equipment at the customer’s site and in accordance with their specific needs. The customer had located the HydroRanger 200 20 to 30 yards from the effluent treatment basin, and this included the availability of 120Vac. The mounting position of the Hydroranger 200 was perfect for the installation of the SITRANS store IQ solution.

A new hardware system developed by Siemens EIS utilized the HydroRanger 200 RS485 MODBUS RTU port and transmitted the data via the Siemens MindSphere cloud platform to the web-enabled Siemens SITRANS store IQ App. The application was configured to extract specific holding registers and meet the remote monitoring requirements of the customer. The entire system included the following items.

•Siemens SITRANS store IQ Enclosure (16”x12”x8”)

•Siemens 24 VDC Power Supply

•SIMATIC S7-1200 Controller

•RS485 MODBUS Communication Module

•Siemens IOT2040 MindConnect Gateway

•Siemens SCALANCE M876-4 Mobile Wireless Router

•AT&T Sim Package Data Plan