The joint and cross-borderPOSIDON pre-commercial public procurement has been a pivotal force in transforming a highly fragmented and innovation-averse sector—environmental remediation of brownfields. Brownfields, sites with limited territorial availability, represent a growing challenge in Europe, where land has become a scarce and valuable resource. The need for sustainable development has intensified the urgency of recovering and reusing these contaminated areas. POSIDON's procurement strategy addresses this by aligning with sustainable growth goals, focusing on in-situ soil decontamination solutions for complex, highly polluted sites. POSIDON PCP is distinguished by its innovative procurement approach, driving the development of breakthrough solutions in areas where no commercially viable options previously existed. Five leading public procurer launched a competitive call for tender to address the decontamination of brownfields polluted by petroleum hydrocarbons and heavy metals. Two cutting-edge technologies—"Soil-Omic with BIOflushing " and "ERASE"—were selected for pilot testing based on their cost-effectiveness and potential to disrupt the market. These technologies represent a leap forward in environmental remediation, particularly for brownfield where traditional technologies have long application times and high costs. The in-situ approaches were tested in Italy and Spain, ensuring their readiness for large-scale application. This PCP initiative has not only fostered the development of these innovative technologies but has also prepared the ground for widespread adoption and market leadership in the European soil decontamination sector. By aggregating demand across borders and ensuring the harmonization of innovation goals, POSIDON exemplifies a transformative shift toward buying innovation process itself, marking a new era in brownfield remediation.