technical BRIEF
BUILDING A SCIENTIFIC FOUNDATION FOR SOUND ENVIRONMENTAL DECISIONS
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RTX:LINK - AN EPANET-RTX SOFTWARE TOOL FOR WATER
UTILITIES TO IMPLEMENT REAL-TIME ANALYTICS
INTRODUCTION
RTX:LINK is an EPANET-RTX-based software tool developed for drinking water utilities, small and
large, to harness supervisory control and data acquisition (SCADA) data and the power of real-
time analytics. RTX:LINK provides a web browser view - via smart phone, tablet or computer -
of all available utility SCADA data through a cloud analytics service to allow the water utility to
remotely access and analyze their SCADA data in real-time. RTX:LINK provides remote access to
all available hydraulic and operational data (e.g., tank levels, flows and pressures) and a few
water quality metrics (e.g., percent tank turnover per day or per week) to help inform and alert
operators, engineers or managers to potential problems. Figure 1 is a schematic of the RTX:LINK
software tool.
Online Dashboards
(SCADA data & Analytics)
SCADA Historian
Fig. 1. RTX:LINK is an open source software tool to help
water utilities make better use of their SCADA data and
implement real-time analytics
The U.S. Environmental Protection Agency (EPA) developed EPANET-RTX as an object-oriented
software library comprising the core data access, data transformation and data synthesis (real-
time analytics) components of a real-time hydraulic and water quality modeling system. The
library was released as an open-source software project on September 24, 2012 to advance real-
time modeling capabilities using the hydraulic and water quality solvers of EPANET. EPANET-RTX
provides the methods and software tools by which operational data can be connected with a
network infrastructure model, and the resulting network simulation model can be calibrated,
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verified and continually tested for accuracy using operational SCADA data. Until now water utility
engineers have been unable to efficiently test and continuously demonstrate that their water
distribution system network model accurately represents system behavior. "Real-time EPANET,"
as it is better described, promises to change the way water utilities, commercial vendors,
engineers and the drinking water community think about modeling. No longer will water utilities
rely on "planning models" for operational analyses, the real-time model will automatically
incorporate actual operational decisions overtime.
To date, EPANET-RTX technologies have been applied at full-scale in eight medium to large
utilities, as well as one small utility. The data requirements of EPANET-RTX for these applications
have been modest, consisting of relatively standard remote telemetry information about
production flows, tank levels, pump statuses, and valve settings. Currently RTX:LINK is being
piloted within the City of Milford, a small drinking water system in southwest Ohio.
DESCRIPTION OF RTX:LII\IK
RTX:LINK provides a simple, secure, read-only access to key operational data streams (e.g., those
stored within a SCADA historian), through web-based dashboards for trending and alerting.
RTX:LINK includes a setup wizard to establish database connections and select the data streams
to archive. It then provides automatic and continuous transmission of SCADA data streams from
the process historian to a modern, high-speed cloud database, and self-configures real-time
dashboards for data visualization.
Two applications of the RTX:LINK software tool will be available depending on the level of interest
of the water utility to connect their SCADA data to a cloud analytics service for anytime-anywhere
access. Here are their specifications:
•	Fully functional, cloud-connected version - Time-series SCADA data analytics will be
provided for all available SCADA data assets (e.g., flows, pump speeds and statuses,
pressures, tank levels, chlorine additions, water quality metrics of interest such as percent
daily tank turnover).
•	Non-cloud-connected version - Single value-based SCADA data analytics will be available
and viewable from a web browser, but only internally from the control room or where
SCADA data access is available and permitted.
RTX:LINK is designed to be platform-independent. The RTX:LINK application will be a cross-
platform executable, and will be able to be run from anywhere in the water utility that has access
to the SCADA historian. Both of these applications will be Microsoft Windows compatible and
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downloadable as a ZIP file with associated instructions, including information related to setting
up the necessary cloud analytics account (if selected by the utility).
RTX:LINK leverages as much utility data and information as is available for greater and improved
decision-making. The piloted version of RTX:LINK within the City of Milford includes a web-based
interface (remotely accessed by the water plant supervisor via his smart phone), which provides
both raw and processed data streams of hydraulic and operational data (e.g., tank levels, flows,
and pressures) and tank water quality metrics (i.e., percent tank turnover per day) to help inform
and alert operators, engineers or managers to potential problems. The next phase of RTX:LINK
testing will be expanded to additional small drinking water utilities. This next phase of testing will
seek to integrate real-time analytics and real-time modeling.
BENEFITS OF RTX:LINK
The benefits of RTX:LINK to the water utility include the following:
•	Staff has anywhere and anytime access to SCADA data analytics via a mobile dashboard.
•	Provides increased attention to potential operational and emergency problems related to
hydraulic metrics, equipment and facility operations. Enables staff to quickly catch a wide
range of potential problems observable through SCADA data (e.g., potential problems
related to pump operation, flows, pressures, tank operation and disinfectant
management).
•	Supports improved water quality management. Disinfectant loss and disinfection
byproduct formation in the distribution system are a function of residence time, which is
affected by day-to-day system operational policies and decisions, particularly those
associated with water stored in tanks. By providing real-time, accurate information about
operational effects on tank residence time and mixing, real-time analytics can improve
awareness of tank water quality, which can lead to operational changes that improve
disinfectant management.
•	An entry point to advanced model-based predictive real-time analytics using both real-
time SCADA data and network infrastructure model to warn of problems.
NEXT STEPS
RTX:LINK is currently being prototyped in the City of Milford, Ohio where it is providing the water
department supervisor 24-hour access to tank levels and turn-over metrics, pump statuses, and
distribution system flows via his smart phone. Milford's Water Department Supervisor, Matt
Newman, states, "Having access to my operational data in real-time keeps me on top of the
system performance even when I am not at the plant. This tool helps me manage my staff and
resources by providing greater flexibility and real-time information."
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The RTX:LINK project team is looking for 4-6 additional, small utility partners to collaborate with
EPA and to further evaluate and test RTX:LINK in their systems. The objective of this next phase
of testing is to use RTX:LINK to bring cloud-based, real-time data analytics to additional
partnering small water utilities to measure key variables related to tank water quality and
clearwell disinfection. Through interactive collaboration, facilitated by regular web meetings,
surveys and data collected by the utilities for compliance or other purposes, the EPA and utility
project team will assess the benefits associated with providing real-time accessible metrics of
distribution system water quality. These collaborations and testing platforms will allow EPA to
further improve the software for future use by all water utilities.
Ultimately, RTX:LINK is planned for distribution as a free open-source product once the project
team has completed its full testing and evaluation at pilot utilities.
EPANET-RTX, including RTX:LINK, development is open to partnerships and collaboration. Both
water utilities and the software development community have participated in pilots to
demonstrate improvements and identify opportunities for enhancements and research, an
approach that EPA values greatly as we strive to develop useful tools to the water industry.
FOR MORE INFORMATION
The intended audience for RTX:LINK are water utilities and their consultants as well as software
developers within the drinking water community. RTX:LINK is an open-source software project
and, if collaborators are interested, there are various ways to get involved (e.g., connecting to
the code repository, looking over coding conventions and using the issues tracker to make a
feature request and communicate with the developers). To learn more about RTX:LINK and real-
time modeling using EPANET-RTX or ongoing enhancements, visit the repositories of EPANET-RTX
and RTX:LINK at https://github.com/OpenWaterAnalytics.
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CONTACT INFORMATION
For more information, visit the EPA Web site at https://www.epa.gov/homeland-security-
researclr
Technical Contacts: Robert Janke (ianke.robert@epa.gov)
Michael Tryby (tryby.michael@epa.gov)
General Feedback/Questions: Kathy Nickel (nickel.kathy@epa.gov)
U.S. EPA's Homeland Security Research Program (HSRP) develops products based on scientific
research and technology evaluations. Our products and expertise are widely used in preventing,
preparing for, and recovering from public health and environmental emergencies that arise from
terrorist attacks or natural disasters. Our research and products address biological, radiological, or
chemical contaminants that could affect indoor areas, outdoor areas, or water infrastructure. HSRP
provides these products, technical assistance, and expertise to support EPA's roles and
responsibilities under the National Response Framework, statutory requirements, and Homeland
Security Presidential Directives.
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