SCADA evolves into the operations and information hub of the future.
These are tough times for water resource managers and utility operators. Stricter regulations, aging infrastructure, and an aging workforce are just some of the many challenges plaguing utilities as they struggle to modernize their facilities. But there is some good news, SCADA (supervisory control and data acquisition)—one of the key technologies for improving performance and controlling costs—now offers more power, more convenience, and more accessibility.
The days of SCADA being out of reach financially (or just too complex for many small and mid-size utilities) has changed. According to Doug Johnson, business development manager, Water/Wastewater Group at Emerson Power & Water Solutions, Phoenix, AZ, “We have customers that range anywhere from the largest wastewater treatment plant in the world in Chicago, which is 1.2 billion gallons per day, down to some authorities that are as small as half a million gallons per day in capacity.”
No matter the size, water utilities are looking to solve common problems of burdensome regulations, insufficient funding, security, and failing infrastructure.
“SCADA is the ideal solution to help municipalities get more predictable operations so they don’t have unplanned costs, plus better diagnostics to make it easier to stay in compliance,” explains Johnson. “And it can help in producing regulatory reports. But as operations grow, it’s important for municipalities, large or small, to have better control and visibility.”
The Human/Machine Interface
Higher visibility was a factor in the decision of the Massachusetts Water Resources Authority (MWRA) to install Emerson’s Ovation human-machine interface (HMI) technology at the Deer Island Treatment Plant. The project is part of a $3.8 billion program to protect Boston Harbor from pollution. The new interface will make it easier for operators to control daily operations and help ensure regulatory compliance. The Deer Island Treatment Plant has been in operation since 1995, and it’s the second-largest wastewater treatment plant in the US. It serves 43 Boston-area communities.
The Ovation system manages and integrates the plant’s legacy systems and numerous processes, including influent pumping, grit screening, primary clarification, oxygen-activated sludge secondary treatment, secondary treatment clarification, sludge digestion, sludge thickening, odor control, disinfection, and effluent discharge. In all, Ovation manages approximately 30,000 I/O (input/output) points.
“Although 30,000 is a lot of I/O points, it’s not on the top of the list,” says Johnson. “In Chicago, for example, we have something like 83,000 items under control, but the numbers are just the tip of the iceberg.”
So, what’s underneath the rest of that huge chunk of ice? Nothing less than a major shift from a past philosophy of upgrading a plant with “islands of automation,” to a new approach of “automation master planning”.
“The idea was to replace an obsolete part of the process with new controls, and there wasn’t a lot of coordination between the various parts of the process which was relatively slow, so it just didn’t matter that much,” explains Johnson. “Today, the municipalities that are doing this right from our perspective engage in automation master planning, which is a long-term roadmap, to ensure that the municipality will get to where it needs to be.”
When water authorities decide to replace their control systems, water resource managers know that their equipment must be able to meet their needs.
“They need to make sure that the equipment has the capability to deploy some pretty sophisticated security capabilities,” elaborates Johnson. “Though they’re doing it right at that point in time, they need to make sure that the decision doesn’t preclude future requirements. In the case of Deer Island, it’s all about the HMI layer of the automation system. If you consider the control room and the CRTs, and operator stations and engineering stations that the operators and engineers use, Ovation ties together all the controls regardless of the manufacturer.”
Implementing an automation master plan brought about some major changes to the operations, equipment, and personnel at the District of Columbia Water and Sewer Authority (DC Water), according to Salil Kharkar, manager of Process Engineering. In the early 2000s, DC Water began a transition from all manual operation to a distributed control system, and undertook some complex capital upgrades. In 2010, after 10 years of work and expenses of $1.2 billion, Kharkar notes that labor costs have decreased and staff has been reduced from 160 to 60 operators, while the plant’s overall efficiency has risen. It’s fortunate that DC Water made the investment, because new mandates will require the Authority to use all the power and control that Ovation offers.
“Since the installation, we have had a couple of regulatory driven mandates that are costing us billions of dollars,” says Kharkar. “One is for enhanced removal of nitrogen to protect the Chesapeake Bay. DC Water already removes the most nitrogen for any plant discharging into the Bay and has consistently met its nutrient removal goals. The new limits ratchet the requirements further and almost down to the limit of the technology. The multi-year project is based on the control system being essential to reducing the cost of operating the ENR process.”
The second big mandate addresses DC’s combined sewer system.
“DC Water is currently constructing gigantic 26-foot diameter tunnels—located underground—that run along, and underneath, the Anacostia River to capture combined sewage flows to convey to the plant for treatment in a new combined sewage treatment plant,” explains Kharkar. “The brand new, 225-million-gallon-per-day [MGD] treatment plant will be constructed on a very small footprint on our existing plant site and will be designed to treat flows that presently overflow into the river during wet weather. Again, Ovation will be the backbone of this process.”
The Value of Data
As trending and data from other areas of operations beyond SCADA become available, there’s a growing recognition of the overall value of data, according to Grant Van Hemert, P.E., Water Wastewater Applications Specialist for the Schneider Electric Water and Wastewater Competency Center, Palatine, IL.
“With GIS, AMI [Advanced Metering Infrastructure], and SCADA systems, you have data coming into separate databases,” says Hemert, “but to ensure that systems work at the maximum efficiency, you need to correlate all this data in one place, and then you can ask yourself, for instance: ‘Is my plant is putting out 4,000,000 gallons of water per day, and can I track every ounce of the water that is produced?’ You should be able to do that.”
Correlation of data involves a merger of SCADA and information technology (IT) as a framework for viewing the total picture. Through its Telvent division, a real-time IT solutions and information provider, Schneider introduced a concept called the Smart Water Network. The network harnesses the integration of IT systems to optimize a water utility’s capacity. Better leak detection is one of many benefits, and by integrating the SCADA system with a hydraulic model, it’s easier for a utility to detect leaks of faulty metering equipment.
“If you have a combined sewer system, you know that once it rains it has to be managed because the storm flow comes into the sewer,” explains Grant. “You may have specific pumps for the sewers, but sometimes they’re kind of hard to get started and running before the storm water comes. But with accurate weather information, you could have the system started and ready.”
In November 2011, Schneider and Telvent took intelligence a step further and announced SmartCity, a concept of providing cities with access to an integrated suite of solutions to improve the efficiency and sustainability of urban infrastructures. The SmartCity management umbrella includes the smart grid, mobility, public services, and of special interest to water utilities—smart water—a package of solutions to help cities manage water networks more efficiently and offer greater resiliency against hazards.
Viewing hazards on video is also possible with the integration of cameras and live video within Schneider’s CitectSCADA or Vijeo Citect products. With video integration in SCADA, information comes in the form of specific process readings, alarms, and trend data. The video displays directly on an operator’s SCADA screen, allowing them to make optimal decisions and actions.
Ethernet technology is a driving force for innovations such as video integration, according to Kip Edgley, vice president, Automation/Integration, Veolia Water North America, Technical Direction Group, Chicago, IL.
“You can use spread spectrum technology and securely push information across the air and distribute Ethernet from one end to the other,” says Edgley, “So not only are you capable of doing command alarm monitoring and status, you’re also able to acquire data from whatever happens to be out at the other end, such as temperatures and visible signals through Ethernet cameras. In some cases, it’s audible information from a particular piece of equipment that may operate at a certain frequency. So if something changes drastically, there are software applications that will map the frequencies and generate alarms. We’re not just talking about controlling something at the end of the line, we’re talking about monitoring it as closely as possible in the same way as if a human was standing there.
A Higher Level of Control
Edgley notes that the benefit is not necessarily a higher level of control, but the ability to have more data from acquisition, to retrieval, to presentment, as well as the ability to exchange data within components. For example, various instrumentation manufacturers are now starting to connect on the Ethernet level. Most notably for Edgley, flow meter manufacturer Endress+Hauser has introduced their flow meters with Ethernet capabilities.
“They are providing Ethernet enabling and enabling the instruments to support different types of programmable logic controller configuration,” says Edgley. “It’s much more efficient and very quick to deploy for the end-user.”
In January 2010, Endress+Hauser introduced the first Coriolis Mass Flow Meter for EtherNet/IP Network use. The Coriolis Mass Flow Meter integrates with the Rockwell Automation Integrated Architecture, and expands the flow of real-time information. Benefits jointly delivered include reduced network count, simpler installation, seamless integration, and reduced programming time.
Accommodating future growth was one of many considerations in the design and upgrade of the Littleton-Englewood Wastewater Treatment Plant in Englewood, CO. In December 2008, a team from Brown and Caldwell, Phoenix, and plant staff wrapped up an eight-year project to upgrade the facility’s SCADA system and treatment operations. Littleton/Englewood processes wastewater from 22 sanitation districts and serves more than 300,000 residents covering a 100-square-mile area. The modernization relies on new, patented processes that reduces nitrate levels, and uses cost-saving waste-flow recycling and an advanced control system to analyze plant performance and diagnose operational problems. The advanced controls of the SCADA system provide in-depth data that allows operators to determine exactly what condition, interlock, or value is inhibiting an operation.
“The system that we had prior to that was basically monitoring only, so it gave us information on what was going on in the plant, but it was very limited in the changes we could make to the system,” recalls Jim Tallent, CWP, treatment division manager at Littleton. “The new system has the capabilities to turn equipment on and off from anywhere in the plant because we have terminals located in all the process areas. We can monitor and diagnose the smart electrical system inside the motor control center, and on some equipment we can monitor voltages on motors and temperatures in bearings on blowers. If I’m away and there’s an issue here at the plant, I can log in remotely and see what’s going on without having to come down and play catch up from that point.”
According to Brandon Erndt, control systems manager at Brown and Caldwell, Littleton was one of the first projects to use a distributed SCADA architecture, and some of the software development and methodologies were different than the standard SCADA approach.
“This is a change we’ve seen in SCADA systems recently,” says Erndt. “In the past, SCADA used to be one standard PC running the SCADA software, but in the last years it’s switched to a distributed architecture where you have a primary server and a secondary server for redundancy, and then a historian server and an engineering workstation, then a server and a domain controller server. So, your SCADA architecture is distributed across four to five physical boxes. Now we’ve been working with a couple of clients to use virtualization software to virtualize the servers and follow the IT methodology. So, we have the convergence of IT and the control world coming together.”
Eight years ago, Erndt recalls that when he started doing SCADA master plans, there wasn’t an IT person in the room. That
changed about four years ago when an IT person was needed for simple tasks such as assigning a port in a firewall to connect to a certain business system. Now during SCADA master planning sessions, it’s not unusual to have two or three IT staffers at every meeting.
As IT converges with SCADA, Erndt sees the outcome as a bridge to the technical drivers pushing SCADA to be an integrated part of overall operations.
Says Erndt, “We have technical drivers, such as wireless mobile applications, and wireless networks for industrialization, tying your SCADA to other business systems, such as performance software, electronic work instruction, SOP, and water modeling software. So, your SCADA is truly becoming the data hub for a lot of other business systems.
Ultimately, the evolution of SCADA to the role of a data hub offers new opportunities for utilities and the water/wastewater treatment industry. The advanced systems provide savings in labor, chemicals, equipment repairs, and energy consumption. As operators harness the value of business systems data, the opportunities for additional savings will grow. So, although SCADA isn’t the cure all for the industry, it’s a long-term technology that can answer many of the tough challenges faced by utilities and operators.
Author's Bio: Writer Ed Ritchie specializes in energy, transportation, and communication technologies.