​​The Drinking Water & Radi​ation Laboratory Branch (DWRLB) offers diverse capabilities and roles and support a variety of Public Health programs by conducting special studies, providing scientific expertise and laboratory services.  DWRLB is the only California government laboratory which provides environmental radiation/radiochemistry measurements, and it is both a US EPA​ and TNI​ certified laboratory for testing chemicals, microbiologicals, radionuclides in water as well as a CLIA ​accredited clinical laboratory for testing toxic substances and their metabolites in human specimens.  DWRLB conducts analytical surveillance of wastewater to detect viral and bacterial diseases to protect, maintain and advance public health readiness against known and emerging infectious disease threats.

DWRLB tests water for toxic metals, such as lead and arsenic, anions such as nitrate, fluoride and cyanide, organic contaminants, such as pesticides and petroleum products, and microbial contaminants, such as fecal indicator bacteria.  DWRL performs wastewater surveillance for infectious diseases such as molecular testing for SARS Cov-2 and other pathogens in including Influenza, RSV-A/B, Flu, MPOX.  The Radiochemistry Unit measures radioactivity in environmental samples and identifies and quantifies​ naturally-occurring and man-made radionuclides. The Biomonitoring Unit provides clinical testing of toxic substances and their metabolites in human specimens and provides emergency public health laboratory services by serving as a surge laboratory for the federal Centers for Disease Control and Prevention (CDC)​.

All DWRLB Units prepare to respond to public health emergencies resulting from natural causes, accidents, or acts of terrorism.