Case Study: Green Infrastructure Options in the Chatfield Watershed
Virridy begins studying Chatfield Watershed
for the Plum Creek Water Reclamation Authority
In July 2023, Virridy began a new collaboration with Plum Creek Water Reclamation Authority (PCWRA) to study an innovative approach to wastewater compliance and watershed restoration. PCWRA provides essential wastewater services to over 100,000 ratepayers in the Castle Rock region of SW Denver, Colorado. The facility expanded in 2019 to be able to discharge a maximum of 9.44mgd to nearby Plum Creek, which drains into the Chatfield Reservoir, located on the South Platte River.
PCWRA is expecting to be required to reduce levels of phosphorus, nitrogen and temperature in its discharge by the Colorado Department of Public Health & Environment in upcoming permits, and has begun to study what facility upgrades may be required to do so. Preliminary projections are that PCWRA will need to add an enhanced BNR upgrade, microfiltration and a double reverse osmosis process for phosphorus and nitrogen reductions, and cooling tower for temperature reductions.
Comprehensive Compliance Options Analysis
In the coming months, Virridy will be conducting a comprehensive compliance options analysis. We will examine the full lifecycle emissions impact of a range of projected facility upgrades, and compare them to the emissions benefit of reducing nutrient runoff and solar loading in both Plum Creek and the South Platte River. Our approach will involve looking at measures such as livestock fencing (and off-channel watering facilities), riparian restoration to develop more stream shade, sustainable on-field practices like cover cropping, irrigation upgrades, small edge-of-field wetlands, and large-scale natural treatment wetlands.
Importantly, we will calculate the amount of carbon credits that could be generated through a new carbon crediting methodology which allows project developers to compare greenhouse gas emissions impacts of different options and monetize that difference if a utility selects the lower-carbon option. This methodology is currently in expert review with Regen Registry. This financial incentive would reduce the costs of a watershed compliance program, while also clearly demonstrating the projected air quality impacts of potential upgrades.
Financial and Ecological Benefits
Virridy CEO Dr. Evan Thomas adds,
“We're thrilled to be working with Plum Creek Water Reclamation Authority on this pioneering initiative. Through this analysis, we aim to demonstrate that carbon finance and environmental compliance can go hand-in-hand, delivering both financial and ecological benefits.
We believe this innovative approach has the potential to revolutionize the industry, and it perfectly aligns with Virridy's mission to drive positive change in water management practices."
Virridy’s work has been made possible by a critical grant by the Gordon and Betty Moore Foundation, as well as a pre-purchase carbon credit commitment by M.A. Mortenson Companies.