Let Data do the Heavy Lifting - Meaningful Dry Weather Flow Reductions Using Remote Telemetry and Collaboration
Flow monitoring data can be used to characterize flow conditions, identify trends and temporal patterns, and measure the effectiveness of control measures. However, flow data is often analyzed and reported months after being collected. We will challenge the audience to imagine innovative ways of providing flow monitoring data to a larger audience while it is still relevant. The presentation will explore a simple and effective approach that empowers everyone from the field teams to the program managers to collaboratively assess, react, and adapt to real-time data through a web accessible portal.
National Pollutant Discharge Elimination System (NPDES) programs require permittees to effectively prohibit non-storm water discharges through their municipal separate storm sewer system (MS4) and implement controls to reduce the discharge of pollutants to the maximum extent practicable. Even though California is officially out of the drought, water conservation efforts continue and prohibitions against wasteful water practices will remain in place. Traditional approaches of dry weather source investigations require labor intensive field inspections that can have limited success observing and eliminating transient flows. Currently, municipalities use staff members to inspect priority outfalls on a scheduled basis. However, most dry weather discharges are transient in nature and often do not coincide with scheduled site visits.
The City of San Diego (City) monitors over 500 major MS4 outfalls and uses significant resources to track down non-stormwater discharges. To maximize labor-intensive field investigations, the City is using real-time data to implement comprehensive dry weather flow reductions. Applying instrument techniques used in the wastewater industry and thinking of the MS4 network as a public utility that requires metering, Alta Environmental developed the MS4 Flow SystemTM. It is a web-enabled flow data system that relies on ultra-sonic sensors, wireless data loggers, and a customizable web portal. As part of an on-going project, the City has been deploying this flow data systems throughout their MS4 network to collect accurate measurements of real-time flow rates and trends. The real-time data is sent to a customizable web portal, where it is organized and displayed to create a hub of data interaction, interpretation, and collaboration among those involved in the project. The web portal can initiate flow based alarms and generate site specific reports to evaluate flows on a daily, weekly, and/or monthly basis.
Throughout the project, the City has developed more accurate estimates of flow rates in their MS4 and used the real-time data to plan targeted field investigations that have led to successful dry weather flow observations and eliminations. Once sites are sufficiently characterized or flows eliminated, the instruments are moved to new locations, providing scalability with only a few instruments. Lessons learned and successes of the City’s on-going project will be discussed.
• How is the approach increasing effectiveness of field investigations?
• What combination of monitoring, data review, and collaboration is required to effectively track and eliminate flows?
• How well does the technology work in locations without intermittent or very low flow rates?
• How much data is needed to evaluate the effectiveness of control measures?
• How can this technology and approach be used in other applications?
The City’s study has shown that real-time flow data collection, interpretation, and collaboration increases the likelihood that flow data are used effectively to implement action and positive change. The approach demonstrates how bridging the gap between the field investigations and the decision makers through collaboration brings out the true potential of the data.
Garth Engelhorn is a CPSWQ and a QISP ToR with more than 13 years of environmental compliance experience with a focus on water quality. He has extensive experience leading stormwater compliance monitoring programs, including the design of watershed assessments, methodologies, automated equipment selection, source identification, data review, data formatting, and compliance reporting. He has performed numerous water quality studies, including, the County of San Diego NPDES storm water program, the City of San Diego’s compliance and TMDL monitoring programs, the Lake Elsinore and Canyon Lake watershed-wide nutrient TMDL monitoring program, lagoon TMDL monitoring investigations, and bacterial source tracking studies.
Heather has been in the San Diego area for 12 years, working in the “water field” in some capacity during that time. Her experience spans from training marine mammals for the military, to marine habitat restoration, to storm water monitoring and management to storm water pollution prevention. After graduating from Scripps Institution of Oceanography with a Masters in Marine Biodiversity and Conservation, she joined the City of San Diego in 2015. Currently, she is the supervisor of the biological monitoring team in the Transportation and Storm Water Department.