This is a Sources Sought Notice for market research, not a solicitation, seeking qualified sources for non-personal analytical laboratory services focused on Low-Level Tritium analysis of aqueous samples for the National Water Quality Laboratory. The required services include analysis of samples from groundwater monitoring wells and surface-water sites, establishing data-quality objectives for the USGS, and providing documentation, data, metadata, and technical support. Responses must be submitted by June 11, 2026, at 2:30 PM MST via email. No budget information or location for performance of services is specified in the description. The government will use responses to make acquisition decisions, and any future solicitation will be posted separately on SAM/FBO.