Recent analysis has confirmed that industrial DDT waste slag (DDT+) was dumped in bulk to the deep ocean (US EPA, 2021) off Los Angeles, not in a containerized form as previously suggested (Chartrand et al., 1985; Kivenson et al., 2019). That is, the DDT wastes are loose in the deep coastal  environment, and not trapped in barrels. This realization leads to several key questions that prevent us from understanding the scope of impacts of DDT+ wastes on ecosystems and human health:
Q1 — How much DDT+ is out there?
Q2 — Where is the DDT+ today?
Q3 — Does the present day distribution of DDT+ enable its environmental mobility and bioavailability?

The answers to these key questions are fundamental to inform our understanding of the deep ocean DDT+ problem, and it is these questions that guide this current research proposal. In this proposal we frame these questions as objectives and use insights from our recent preliminary studies to address them through an extensive field sampling and analysis campaign. For this project we have teamed three experienced investigators (David Valentine from UC Santa Barbara; Eunha Hoh and Nathan Dodder from SDSU) with complimentary expertise and proven track records in DDT+ research to investigate the distribution and biogeochemical behavior of DDT+ wastes dumped to the deep ocean floor, with a focus on short dumping of DDT+ wastes between the California mainland and designated dumpsites in the San Pedro and Santa Monica Basins. We have also prepared this proposal in consultation with other scientists proposing complimentary research or engaged in complimentary activities supported by other means. Notably, we have close ties to proposals led by Tina Treude, Eunha Hoh, Erin Satterthwaite, Will Berelson, and Amro Hamdoun, and to federally-funded research being supported through Scripps Institution of Oceanography.