Broadening the Sphere of Control
The Passaic (N.J.) Valley Sewerage Commission (PVSC) processes more than 25% of the wastewater produced in the state of New Jersey. With an average influent flow of 330 mgd, it is a large operation that is dependent on accurate, real-time data for day-to-day decision making.
Beginning in 2001, PVSC upgraded its aging process control system, an investment of time and capital that has been well worth the effort. At the same time, the utility was able to provide plant-wide access to all of its key operational data through the e-OPS system provided by EMA, a consulting firm retained to assist with PVSC’s process control systems. EMA provided overall network and system design, specified equipment, database design and web-based data integration, and assisted PVSC personnel with installation.
“PVSC had a proprietary system, and it was becoming very hard to maintain,” explained John Pasini, region IT practice manager for EMA, who managed the project. “The system operated almost like a mainframe. Parts weren’t available. It was obvious we needed to move to a more open technology so that the utility was not dependent on a single vendor.”
Today, the system automatically collects real-time data from the Process Control System and the Laboratory Information Management System (LIMS), as well as several other PVSC systems. Access to the data is via open web-based technologies.
“The old system ran on proprietary networks,” Pasini said. “For the new system, we went to an Ethernet network, which makes data communications and sharing much easier. At the time we did Ethernet at PVSC, it was seen as kind of risky. Now, it has become very common.”
The new system has the advantage of being totally “open” with all of its components replaceable with parts from different vendors. Purchasing of all hardware and software was done using existing procurement contracts, eliminating the need for additional bidding and the creation of bid documents. In addition, PVSC was able to purchase the precise hardware and software desired.
This system has enabled PVSC to automate its reporting and enhance access to key operational indicators. PVSC staff is able to make intelligent, informed operating decisions whether they are in the plant or using a different PC from a remote location.
“The sphere of control is much broader in the plant, and the processes are each managed locally where possible,” Pasini said. “The flexibility and the ability to distribute the processing is so much greater with this system.”
Overcoming data isolation
Operators at PVSC have always required data from the Process Control System and the LIMS in order to make day-to-day decisions on how to most efficiently run the plant. To accomplish this, a large number of intricately linked spreadsheets were designed to facilitate data capture, entry and summarization.
This required that many different personnel all over the plant do daily process data entry. Laboratory data is also required, and laboratory staff had to populate spreadsheets as well as their own LIMS, causing substantial duplication of effort. There were even situations when the lab would also provide telephone updates on critical data points, in addition to the spreadsheet entries and LIMS data entries.
“We had a system before, but it wasn’t available for everybody,” said Paul Cavanaugh, a PVSC engineer who worked on the project. “Now, more people can get more data, and they can get it faster and more efficiently.”
The spreadsheet data entry system was a good solution when it was implemented, providing the plant with important information. PVSC recognized, however, that automated data acquisition would greatly increase the accuracy of results, while dramatically decreasing the workload of the many plant personnel who did daily data entry.
To add to the complexity of the problem, it was quickly becoming apparent that today’s requirements for intelligent plant operations were driving PVSC to integrate data from other systems into their daily analysis of operations. These systems included their Computerized Work Management System (CWMS), financials and trucked-in waste tracking system.
One of the primary goals of this project was to provide an automated, secure, data-sharing environment for PVSC staff that would eliminate the time-consuming job of entering data into multiple spreadsheets and systems. As at most utilities, data at PVSC has historically been treated as though it were owned by one department. In the case of process control, data is typically owned by the plant operators, as they use it to run the plant more efficiently. Plant operators may also have access to some subset of laboratory data (the spreadsheets in PVSC’s case), either through a printed report or some other direct contact with the lab.
Web-based data integration
With the advent of web-based technologies, data warehousing tools and object-oriented programming techniques, strategies are available to allow access to data from many diverse systems in an intelligent, interrelated manner. These techniques allow sharing of data with a wide audience without affecting the performance of sensitive operations such as process control. The approach taken at PVSC used a web-based front end to a common data store (eOPS) for well-defined subsets of data from the plant’s Process Control System, LIMS, Industrial Monitoring and Control System, Financial Information System, CWMS and Trucked-in Liquid Waste Tracking System.
“e-OPS is also available on the business side of the network, not only on the process side,” Pasini explained. “There are a number of different impacts. For example, the utility has automated the production of their regulatory reporting on e-OPS. Another benefit is the ability to look at a couple of different dashboard screens and make quick decisions on how the plant is running so they can fine-tune day-to-day operations. It is a very practical tool.”
“[The] e-OPS system enables us to pull live data to the web page without having to pay an annual licensing fee for every user,” Cavanaugh said. “e-OPS puts everything in place and makes it easy to develop whatever reports you need. When it was all in spreadsheets, you maybe had to open a dozen spreadsheets to build the report. Now, the users have the ability to customize e-OPS to their needs.”
There are a number of database links established for use by the database server to allow data retrieval from the other PVSC enterprise systems such as the LIMS and CWMS. These data sources include the six WonderWare area servers, which collect plant process data. WonderWare stores its data in a Microsoft SQL Server-based database with proprietary extensions. These SQL databases provide the local operations personnel with localized data trending displays for their specific areas. The JAVA data collector program provides data acquisition and translation services required to move this data into the Oracle-based database that shares the data with other plant personnel.
A subset of plant data is retrieved from the data historian and transferred to the database server by the JAVA data collector program that wakes up every 15 minutes to provide this data transfer capability. In this way, any recent process data is always available to users of the system without giving them direct access to the Process Control System. Similar techniques are being used to harvest subsets of data from the other key enterprise systems. The data is inserted into the database by each of these data collectors, and the database aggregates and stores the data for integration and retrieval by its users.
“The utility has extended the system over the years and added some meaningful pages without our assistance,” Pasini said. “They’ve extended its capabilities and used it to fine-tune their processes.”
Simple, centralized data access
At PVSC, end users of e-OPS interface with the system via a web browser, shielding them from all of the technology that makes it possible. The typical user opens his or her web browser and navigates to the e-OPS home page. The user is greeted by a sign-in screen, requiring a user ID and password. End-user privileges and functional capabilities on the system are determined by the permissions assigned to each user by his or her administrator. A typical user will be allowed to view standard and custom reports as well as perform ad hoc queries of the database.
The report presentation is provided to the user based on specific needs. The user can choose from a web-based report, a presentation-quality report formatted for printing, a spreadsheet format or a PDF file format. The reports are available in both tabular and line graph formats and can be e-mailed. PVSC personnel were trained to program the system so that functionality could be enhanced without external assistance.
Variety of benefits
Since implementation, PVSC has realized a substantial number of benefits from its new control system, including:
- One-time data entry and a single point of access to a wide variety of information from multiple systems;
- No client software required on individual PCs, only a web browser;
- Preservation of system security and integrity of individual PVSC systems, including a full audit trail;
- Users receive automatic e-mail notices per user-defined limits, e.g., when past due work orders approach a set number or when purchasing should reorder sodium hypochlorite to replenish the supply;
- Savings on licensing fees; and
- Ease of integration of new data sources.
The addition of the database system provided an automatically populated central data store that collects real-time data from the Process Control System, LIMS and several other PVSC systems. The web-based approach gives PVSC staff an easy-to-use universal and effective tool for their key data and operational indicators. The end result is improved data management and overall operations.
“This project isn’t really over. It’s a living network, and changes are being made day-to-day,” Pasini said. “It’s growing with the plant. As things change in the plant, they make changes in the system.”