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

usa.siemens.com/monitoring-apps

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