Lynchburg, Va., overhauls its CSO system & notifies the public
Lynchburg, Va., uses a combined sewer system that carries both sanitary sewer flow and storm water to the Lynchburg Regional Wastewater Treatment Plant for processing during rain events. However, during a heavy rainstorm, increased flow can overload these collection systems, resulting in discharges and a combined sewer overflow (CSO). The city has aggressively worked for the past three decades to reduce and eliminate these overflows through its CSO program, and it is developing a plan to separate the sanitary and storm systems as one of three options prescribed in the federal CSO policy. Additionally, the city has been actively working to increase awareness of the impact of these events on public health and the environment.
In 1979, the city of Lynchburg began an extensive plan to separate its combined sewer system into two different systems: sanitary and storm water. At the time of the project’s inception, 132 overflow points were identified within the city’s combined sewer system—and these overflow points annually discharged more than 1 billion gal of combined sewer and storm water material into the James River and its surrounding watersheds. This process was extraordinarily costly and time-consuming, and between 1993 and 2017, more than $245 million was spent in separating the combined sewer lines to close 113 overflow points.
Impressively, closing these 113 overflow points resulted in an 85% reduction of overflow volume; however, closing the remaining 19 overflow points and fully separating the system would cost more than $260 million and take decades to complete. Being one of the most fiscally stressed localities in Virginia, Lynchburg Water Resources—the city department responsible for managing water, wastewater and storm water—sought a more cost-effective and feasible way to comply with the Federal CSO Policy.
Over the past decade, the city worked on a revised Long Term Control Plan, revising the James River Bacteria Total Maximum Daily Load (TMDL), and coordinating with the Department of Environmental Quality to revise the CSO Long Term Control Plan to achieve better water quality more quickly faster, and at a lower cost by instituting a plan to capture and treat much of the remaining combined area. As a result, the city entered into a new Consent Special Order in 2015 with the Virginia Department of Environmental Quality and State Water Control Board to implement a new plan.
As of 2018, 4% of the city is serviced by a combined sewer system. Under this new Long Term Control Plan, the remaining overflow points will be reduced to just 17 out of the original 132. The majority of the combined flow will be transported to the Lynchburg Regional Wastewater Treatment Facility, which currently is undergoing a $54 million upgrade to help process the additional flow. With this upgrade, the plant will increase its treatment capacity from 44 mgd to 80 mgd, with a small amount of combined flow being discharged into the watershed. Within the next decade, the city estimates it will complete its combined sewer program, resulting in a 93% total reduction in combined sewer overflow volume from the levels seen prior to 1979.
The program includes more than just infrastructure upgrades. As part of the Long Term Control Plan, the city developed a public notification and awareness system for greater transparency and real-time information to the public regarding the environmental implications of combined sewer overflows. While the Lynchburg team wanted to build something to provide valid data as quickly as possible, protecting critical infrastructure by not allowing the public direct access to control systems was of utmost concern. The challenge then was to quickly implement a secure, cost-effective, accurate and robust solution to notify the public with valid, accurate information on overflows while still maintaining a high degree of security for the city’s infrastructure network.
Prior to this discussion, Lynchburg Water Resources already had been using an Inductive Automation Supervisory Control and Data Acquisition (SCADA) system for remote monitoring of some of the combined overflow sites. Since the SCADA system already read levels and triggered alarms for internal use, it made sense to find a way to securely publish those existing alarms to the public. Some of the challenges inherent in this solution, however, included the need to filter erroneous data and the ability for the public to manage their interactions with the system.
Another existing tool in the city’s toolbox was the mass notification system called “Lynchburg Alerts,” which was developed by Everbridge. This opt-in emergency notification system enables the city to issue text or email alerts to the public regarding adverse weather, public safety concerns, or other pressing pieces of public information. Since the Everbridge system already met the needs of public credential management, city transparency and a solid public notification infrastructure, it became the choice for issuing CSO alerts. In working with consultants for both systems, It was quickly determined the SCADA system could interface with the Everbridge notification system to publish the CSO alerts as well.
A Logical Choice
Finally, the city needed to find a way to add logic into the system to mitigate false alarms and prevent subscribers from being flooded by multiple alerts during a single CSO event. A Bedrock Open Secure Automation system already provided cybersecurity and logic controls of sensors, pumps and other field instruments. Since industrial controllers are designed for continuous long-life and harsh service operations, leveraging one for the bulk of the logical operations of the project made sense. Importantly, the Bedrock controller already supported the industrial protocols necessary to read the level data, and while it could filter and generate alarms, it was still secure and robust enough to trust for critical plant operations.
Simulator to Solution
The Bedrock integrated development environment (IDE)-the software used to configure the system-includes a simulator capability. This allowed the code to be built, run and validated in the programming environment, decoupled from the physical hardware. This was especially important because the Lynchburg Water Resources technical team was working with a remote system programmer based in North Carolina. Through the simulator, the programmer could test, debug, and commission code from his North Carolina office simultaneously while the physical hardware was being installed and commissioned on site in Lynchburg.
This simulation allowed both teams to confidently combine factory and site acceptance testing, which cut the deployment time in half compared to similar past projects. Since the code already was tested and proven, onsite startup was completed in one day. It also gave the Lynchburg technician the ability to test future modifications before making changes on the live system, something common in today’s information technology world, but very uncommon in the industrial control environment.
Proving a Program’s Success
Although a working solution that leveraged three major existing pieces of technology-the Everbridge alert system, the SCADA system and the Bedrock controller-was prototyped, built and deployed in record time, the city still needed to make the system public. In Spring 2017, Lynchburg Water Resources developed a public information campaign to launch the alert system, which coincided with the go-live date of May 1, 2017. Elements of this campaign featured website development, social media campaigns, and an interactive GIS-powered map called “Find My Sewershed.”
Specifically, the map allows for individuals to type in addresses to determine if properties are located within a combined sewer area. It also features the exact location of each remaining CSO point along with a photograph of the overflow pipe. Since the James River (part of the Chesapeake Bay watershed) is used by many outdoor enthusiasts, including boaters and fishers, this map allows for recreationists to pinpoint overflow areas and avoid them during periods of intense rainfall.
Since May 2017, 10,000 individuals have signed up for Lynchburg CSO Alerts and more than 30 incidents have been sent to the public. Several local nonprofit partners help blast out this information, including the James River Assn., an environmental organization that promotes the conservation and responsible stewardship of the James River. Targeted social media campaigns have been used both to educate citizens about the history of Lynchburg’s combined sewer system and to urge for concerned individuals to sign up for alerts.
Although the city does not advise on behavior changes during a combined sewer overflow, the fact that the information is being transmitted to the public in a timely and transparent manner proves the program’s success and positions the city to be a leader in completing its combined sewer program in an effective, timely and efficient manner.