Novel field trial for oceanalkalinity enhancement usingelectrochemically derivedaqueous alkalinity

Frontiers in Environmental Engineering | September 19, 2025

By Allison M. Savoie1, Mallory Ringham, Carolina Torres Sanchez, Brendan R. Carter, Sean Dougherty, Richard A. Feely, Dave Hegeman, Julian Herndon, Tarang Khangaonkar, Jeremy Loretz, Tyson Minck, Todd Pelman, Lakshitha Premathilake1, Chinmayee Subban, Jesse Vance, and Nicholas D. Ward

Ocean alkalinity enhancement is an emerging approach to marine carbon dioxide removal that increases the ocean’s ability to absorb and store CO₂ for the long term while potentially reducing local acidification. A recent field study in Sequim Bay, WA, tested this method by adding electrochemically generated alkalinity through an existing wastewater treatment plant system. The trial, carried out by industry, academic, and federal partners, showed that the alkalinity release raised local seawater pH near the outfall but quickly diluted within a few meters, with no measurable impacts on temperature, salinity, turbidity, or oxygen. These results provide an important proof-of-concept for safe, small-scale releases of alkalinity-enhanced seawater, helping advance research on ocean-based climate solutions.