Integrated Watershed Management: Better Data Means Better Decisions

Background
The City of Richmond Department of Public Utilities (DPU) includes three utilities: water, wastewater and stormwater. This lead the City to determine an integrated watershed management approach would be best service the needs of the community, the environment and ensure water equity to all of its constituents. Recognizing the importance of water and the significant interest in how the resource is managed, DPU has historically worked with many different stakeholder groups. In 2014, DPU launched an initiative called RVAH2O to increase awareness about the importance of water and to also better coordinate efforts with stakeholder groups designed to improve water quality in the James River. The RVAH2O group produced the RVA Clean Water Plan in 2017. The group used EPA's Watershed Management and Integrated Planning Framework guidance to produce the Plan. The primary difference in the City's Plan versus what EPA recommended was the plan included stakeholder involvement during the entire development of the Plan and now during implementation. During development of the plan, stakeholders agreed that DPU's overarching goal should be to improve water quality, which includes reducing bacteria levels to meet local TMDL and water quality standards. Richmond, like many older cities, is equipped with a century old combined sewer system that includes 25 combined sewer overflow (CSO) outfalls that contribute bacteria during most wet weather events. Despite DPU's efforts to improve the sewer collections system, the challenges related to climate change are bringing an increasing number of wet weather events to Richmond and spurred the City to identify alternative methods to increase the utilization of the collection system to reduce overflows. Additionally, in 2020, the Virginia General Assembly required the City to control CSOs to a level that would comply with James River bacteria total maximum daily load (TMDL) by 2036, and dictated the City develop and implement an Interim Plan and Final Plan. The Interim Plan was to describe short-term projects that could be initiated within a year, completed in five, and shown to have quantifiable impact on CSO discharges. The Final Plan is to describe longer term projects that will be completed by 2035 and that will meet the requirements of Richmond's existing Consent Order.
Importance of Data
Historically, DPU's sewer collection system was a passive system that relied predominantly on manual operations. For many years, DPU used hydrologic and hydraulic (H&H) models to identify CSO discharge volume, but the model performance and accuracy was limited by available rainfall and flow data. Beginning in 2017, DPU recognized the need to address the problem of the overflows and investigated newer technology to assist with this effort. This led to installation of a real-time sensor network to critical areas of its collection system. Depth sensors, flow meters, and rain gauges were added to strategically significant areas throughout the network to collect real-time performance data. This was the basis of building a real-time decision support system (RT-DSS) that allowed DPU to clearly visualize the operations of its sewer collection system. The RT-DSS is viewed through several dashboards that allows DPU to see both current and historic data from each sensor, CSO outfall, and other important areas in the sewer network. The dashboards also provide recommended actions for the operations staff at the Shockoe Retention Basin, Hampton-McCloy Tunnel, and the Wet Weather UV system at the wastewater treatment plant. The RT-DSS data combined with historic network data enabled DPU to develop the required Interim Plan within the time required by the legislation. Initially, the team was able to identify 18 potential projects which would reduce CSO overflows across the City's network. Advanced modeling (collection system and water quality) and simulations were performed to quantify the additional capture of each of these projects as well as a community, environmental, and operational cost-benefit analysis. Upon completion of this work, a final group of 10 projects were included as part of DPU's Interim Plan to meet the legislative requirements. Planning and design work have begun on the Interim Plan with the 10 projects expected to reduce ~182 MG of CSO annually into the James River. More importantly, these projects only require a mitigation cost of $0.18 / gallon, which is half of the previous CSO projects financial impact. The City of Richmond is an Environmental Justice Community with ~23% of the City's population below the poverty line. The ability to use existing infrastructure instead of building new infrastructure at a much higher cost is crucial for the City. The data provided through the RT-DSS has been a key to this approach. Additionally, DPU's confidence in the accuracy of the sensors and the RT-DSS allowed them to build a CSO dashboard on its public website that allows the community to view the positive impacts DPU is making on the environment and the James River as well as shows where CSOs have been activated in the last 48 hours during wet weather events. DPU is now measuring and monitoring the real-time response of its system based on site-specific rainfall data through the RT-DSS. These collected data also support DPU's continuous improvements to its H&H models. The data, plus continuous improvements to the H&H model as well as the water quality model allows DPU to better use limited resources. The additional data collected through the RT-DSS system also informed a pilot study to assess and quantify temporal and spatial differences in bacteria concentrations at different outfall locations. DPU also works with Virginia Commonwealth University (VCU), local environmental groups and Virginia DEQ to collect water quality data on the James River. All of these data work together to help DPU make better decisions. VCU is also doing bacteria source tracking (PCR testing), which is a key piece to understanding the bacteria water quality issues in the James River. An additional key data piece is the upcoming bacteria sampling/monitoring of CSO discharges that will help DPU verify/update the bacteria event mean concentrations used to characterize the CSO discharges and their impact on the water quality of the James River. The presentation and manuscript will describe how DPU has changed its approach for managing its CSS. The presentation and manuscript will discuss the importance of data and how the tools for collecting, managing and applying these data across different use areas is beneficial for a utility. There will also be discussion of future plans for expanding the system to allow the utility to operationalize the data for more informed decision making, better planning, and more cost effective projects to reduce CSOs and to better manage wastewater treatment operations, water treatment operations and water quality in the James River – moving toward a One Water Approach.