Challenge

Clean Water Services (CWS) needed assistance in carrying out a long-term water resources plan to improve watershed health, enhance streamflows, restore aquatic habitats, and identify actions to manage a large water rights portfolio within the Tualatin Basin.

Solutions

CWS contracted Geo-Logic Associates wholly owned subsidiary Summit Water Resources to support several water resources initiatives.

GLA assessed innovative tools to potentially add to CWS’s water quality credit trading program for temperature. Our team began by supporting a feasibility study for using aquifer storage and recovery (ASR) as a water management tool to mitigate thermal impacts from the District’s water resource recovery facilities. We supported the following technical aspects of the feasibility study: assessing the availability of cold wintertime source water for subsurface storage, characterizing the local hydrogeologic setting, identifying permitting strategies and roadmaps, estimating the quantity and quality (including temperature) of stored water during recovery, characterizing potential impacts to existing water users and environmental conditions, estimating potential benefits including generation of thermal credits, and developing preliminary ASR system designs and planning level capital and operation and maintenance costs.

We also assisted CWS with management of the District’s water right portfolio, including inventorying all District owned water rights, verifying compliance with Oregon Water Resources Department (OWRD) standards, and identifying and prioritizing any actions required to maintain the water rights in good standing with OWRD. Additionally, GLA identified and implemented strategies to manage unique water rights assets such as Municipal Reclaimed Water Registrations and instream leases. Further, Summit is currently providing support with an ongoing investigation of potential sources, extent, and fate and transport of per- and polyfluoroalkyl substances (PFAS) in shallow groundwater across the Tualatin Basin.

Results

The thermal ASR feasibility study indicated that storing cold (<10°C) water in the subsurface during the winter and then recovering stored water during the summer for streamflow enhancement of 303(d) impaired waterbodies and aquatic habitat restoration is likely feasible and can provide significant benefits for the watershed. A roadmap for further implementation of this innovative approach to water management and thermal compliance was developed.

GLA helped CWS identify immediate actions to keep its water right portfolio in good standing and improve the value and use of its water rights. Our team is also helping CWS develop long-term strategies in alignment with CWS’s values for managing its water right portfolio and supporting its water resource initiatives in the Tualatin Basin.

Our support for CWS’ PFAS initiative successfully identified 12 privately owned wells for sampling of PFAS. To-date, two sampling events have been completed, which has improved CWS’ understanding of the extent of PFAS in shallow groundwater of the Tualatin Basin.

Our team strives for the most innovative approaches for our clients.”