City of Norman, Oklahoma, USA – Exploring reservoir augmentation for climate resilience
The City of Norman currently relies on Lake Thunderbird for roughly 60% of its water supply. Approximately 32% of water comes from groundwater wells (43 wells), and 8% is provided by purchasing wholesale finished water from Oklahoma City. Norman has been fully utilizing its lake portion since 1998 and realized from the droughts of 2006 and 2012 that the lake firm yield is less than ideal.
In 2012, the Oklahoma legislature passed the Water for 2060 Act, with a state-wide goal of consuming no more fresh water in 2060 than was consumed in 2010. The Oklahoma Department of Environmental Quality began an aggressive campaign to promote both non-potable and potable water reuse regulations. By expanding its existing water reclamation and reuse with an indirect potable reuse project through Lake Thunderbird, the City of Norman plans to trim the demand placed on its groundwater supply and potentially eliminate a need to purchase finished water. The project would take highly treated water from the Water Reclamation Facility and return it to Lake Thunderbird, providing a more drought-resilient reservoir.
The communities of Midwest City and Del City also utilize Lake Thunderbird and are being kept up to date with all updates as it relates to the possibility of augmenting the lake when needed due to droughts. Norman maintains close lines of communication with them as Norman is working through the reporting stage of the pilot project, with the assistance of Garver, that tested two Biological Nutrient Removal trains and followed with Ozone/Bio-filtration and then UV/hydrogen peroxide. Preliminary results of the treatment methodology were very promising. The project will determine if indirect potable reuse for Lake Thunderbird is cost-effective. The pilot project was partially funded with a grant from the Bureau of Reclamation, and focused on treatment schemes that would be more feasible for inland states that can’t easily use reverse osmosis with a brine discharge and the additional costs associated with a significant brine handling system.
Members of a Citizen Advisory Committee from Midwest City, Del City, and Norman met regularly during the pilot to oversee the project and communicate with respective communities. The Citizen Advisory Committee is anticipated to continue meeting at key milestones as the project progresses. The water quality targets from this project are set to meet the Safe Drinking Water Act requirements and would potentially benefit wildlife, boaters, recreation, and tourism in the area by helping to maintain lake levels and provide a drought-resiliant municipal water supply for the cities of Midwest City, Del City and Norman.
In parallel, Norman is working with the University of Oklahoma, in partnership with the National Science Foundation, to research wetland treatment for various constituents of concern. In addition, the Bureau of Reclamation is funding research along with Environmental Protection Agency, United States Geological Survey, and University of Oklahoma into wetlands treatment to allow for stormwater treatment of phosphorus and nitrogen. They are researching the potential to have a dual wetland for both stormwater and environmental buffering/polishing of reclaimed effluent. This research is halfway into the initial planning phase, with the Environmental Protection Agency about to drill monitoring wells near land at the Water Reclamation Facility. This land is proposed to construct pilot wetlands to further research the stormwater/effluent concepts.