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  • A deeper look into Wastewater's SCADA system

    Dec 03, 2015 | Read More News
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    The Pima County Regional Wastewater Reclamation Department (RWRD) has taken significant steps to protect the safety and health of its citizens, and protect the environment by preserving one of Pima County’s most precious resources: water.  

    Using a high-performance Supervisory Control and Data Acquisition (SCADA) system based on situational awareness, a mobile work force, and a decision support system, RWRD provides stellar management and maintenance of the Pima County sanitary sewer system. Situational awareness enables staff to employ techniques to better perceive, comprehend, and project what is happening in its wastewater reclamation facilities.  

    “We have an average daily flow of approximately 60 million gallons; we have 3,700 miles of sewer lines, 27 lift stations, and 77,000 manholes,” said John Sherlock, RWRD’s deputy director for treatment. Pima County’s sewer system serves a population of close to a million people.  

    The Tres Rios Wastewater Reclamation Facility, one of nine in Pima County, recently received an upgrade from conventional pollutant removal technology to a state-of-the-art nutrient removal system. “Our typical ammonia values are coming in at between 30 and 40 parts per million, and with current treatment technology, we remove 99 percent of that ammonia.  Our typical discharge into the Santa Cruz River is one part per million ammonia,” said Sherlock.

    Automation plays a critical role in running the Tres Rios facility. The automation system used to run the facility utilizes Wonderware software programs. Wonderware is part of the SCADA solution and allows Pima County to do more with less by simplifying the complexity of wastewater renewal.

    “A significant benefit of the new SCADA system at Tres Rios is that it has allowed RWRD to double the capacity of the plant, while operating with the same amount of people as before the expansion. That would roughly equate to a 50 percent increase in operational efficiency,” said Rod Graupman, retired RWRD SCADA manager with a keen understanding of SCADA capabilities.

    Always on the leading edge of technology, Pima County also uses Wonderware Intelitrac, a mobile computer that captures field data and allows for increased accountability.   

    “Intelitrac allows us to take information from the plant that was not previously available on SCADA.  We can take select information and load it to SCADA so that it is trendable, alongside of information that is available,” said Chris Grant, RWRD program coordinator in the technical services division.

    SCADA continues to constantly evolve and improve. “Intelitrac has allowed us to capture institutional knowledge. Individuals who have been here for many years have been extensively interviewed, and we have incorporated their knowledge into the electronic rounds to help new operations and maintenance technicians, and to help with training,” said Grant.    

    “A couple of things were done with our situational awareness: we wanted to keep it focused, keep it simple, keep it easy on the eyes, and ensure that things requiring attention, get attention,” said Larry Sawicki, RWRD process control program manager. 

    This situational awareness strategy implemented in Pima County’s SCADA system uses goal-oriented design, effective window structure, color usage and alarm management. “We’ve witnessed a distinct improvement by operators noticing that things are going well and taking suitable response and action,” said Sawicki.   

    The effects have been quite dramatic. Operators who previously ignored nuisance alarms now take immediate action. We can identify and address problems before they escalate.  

    Wonderware engineers worked closely with RWRD staff to architect the system and implement best practices. “Pima County embraced the technology, and ran with it. Every now and then they come across a technical hurdle, so they come to us for answers and together, we architected a great system for Pima County,” said Brian Farner, senior system consultant for Wonderware West.

    RWRD’s investment in SCADA is expected to drive down the cost of conducting business, increase operational efficiency, promote safety, and support a sophisticated mobile workforce and decision support system.