Chemistry & Radiochemistry Section (CRS)
Dr. Raimund Roehl, Section Chief
Dr. Syrago-Styliani Petropoulou, Unit Supervisor
The DWRLB Chemistry Unit (CU) provides a wide range of testing services for inorganic and organic contaminants in drinking water and drinking water sources. This includes regulated toxic metals (e.g., arsenic, lead, cadmium) determined by sensitive analytical techniques such as Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). ICP-MS is also increasingly used to determine unregulated metals and for quantitation of long-lived radionuclides. CU also determines anions by Ion Chromatography (IC) and Ion Chromatography coupled to Electrospray (ESI) MS and ESI tandem MS. These anions include: common anions (fluoride, chloride, sulfate, nitrate, nitrite, phosphate); disinfection by-products (bromate, chlorite, chlorate); and miscellaneous anions (perchlorate, chromate, hexavalent chromium). General water quality parameters are determined by ion-selective electrode, spectrophotometry, distillation, amperometry, and titration techniques.
DWRLB relies on instrumental analysis to analyze many organic contaminants including gas chromatography, liquid chromatography, and mass spectrometry methods in a variety for forms (e.g. purge & trap GC-MS). Organic contaminant testing includes analyses for federally-regulated and California-only regulated contaminants in drinking water using both the USEPA 500 series methods (approved for drinking water) and the USEPA 600 series methods (for wastewater).
Dr. Shiyamalie Ruberu, Unit Supervisor
The Radiochemistry Unit (RCU) of DWRLB is the only State laboratory capable of conducting radiological testing on environmental samples. As the primary drinking water laboratory for the State of California, RCU is certified by the USEPA to test all regulated radioactive contaminants. Drinking water is tested for three types of radiation (alpha, beta and gamma) to determine compliance with the Safe Drinking Water Act regulations under the Radionuclides Rule.
RCU supports the Radiologic Health Branch in monitoring environments surrounding the nuclear power plant sites in California (San Onofre and Diablo Canyon). Water, air, milk, soil, sediment, vegetation and biota are analyzed for fission products which can reveal accidental releases. RCU also monitors air samples throughout the State for ambient radiation. Air sampling stations are located in Eureka, Diablo Canyon, Livermore, Long Beach, Richmond, San Diego, San Luis Obispo, and San Onofre. Weekly air samplings detect airborne radionuclides that could be released anywhere around the globe, for example, elevated radioactivity was measured for six weeks after the Chernobyl accident in 1986, and also after the Tokaimura (1999) and Fukushima (2011) incidents.
Another major area of work is enforcement/compliance and decommissioning/decontamination. Radioactive materials are used widely in manufacturing, research and hospitals throughout California, and these facilities require periodic testing for surface contamination. As sites are decommissioned, analyses of environmental samples are performed to demonstrate that radioactivity does not exceed background levels before these sites are released for unrestricted use. Currently samples from the former military sites of Treasure Island, Hunters Point Shipyard, McClellan Air Force Base, Alameda Naval Station and Mare Island are being tested by RCU.
RCU is part of California's Nuclear Power Plant Emergency Response Program (NPPERP). In this capacity, RCU will receive environmental samples during the re-entry phase of a nuclear incident. Following such an incident initial field monitoring will be conducted by Federal agencies. If necessary, RCU could receive contaminated environmental samples for analysis. RCU is equipped with a special Semi-Hot Laboratory where moderately radioactive samples can be handled.
Research and method development is an important part of RCU's activities. Achievements in this area include the development of methods for the detection of lead-210 and polonium-210 in water sources, the detection of gross alpha and gross beta activities in water by liquid scintillation spectroscopy, improvements in measuring radon in ground water and a comprehensive survey of the occurrence of radioactive elements (e.g., radium, uranium) in California's groundwater wells.
Microbiology & Biomonitoring Section (MBS)
Dr. Alon Volner, Section Chief
Dr. Chad Crain, Unit Supervisor
DWRLB also houses CDPH environmental microbiology services and expertise in its Microbiology Unit (MU).
MU is certified by US EPA to perform drinking water microbiology measurements including fecal coliform testing mandated by both the federal Revised Total Coliform Rule and Surface Water Treatment Rule and Heterotrophic Plate Count (HPC) testing mandated under the Clean Water Act. These procedures detect presence/absence of total coliforms and
E. coli bacteria and enumerate coliforms as well. In addition to the traditional culture-based methods, DWRLB is actively developing molecular based methods for a variety of applications in environmental microbiology including recreational water quality rapid indicator methods for enterococci bacteria, and parasites such as
Cryptosporidium. This work, in collaboration with local public health departments, EMB and other CDPH labs relies on novel biotechnology techniques including polymerase chain reaction (PCR), quantitative PCR and others to identify and enumerate both pathogens and indicator organisms in California’s water supplies, wastewater and beach locations.
Dr. Wenlu Song, Unit Supervisor
The Biomonitoring Unit within DWRLB houses the Laboratory Response Network – Chemical (LRN-C) laboratory at CDPH. The LRN-C laboratory network is coordinated by the Centers for Disease Control and Prevention (CDC) which supports 62 U.S. state, territorial, and major metropolitan labs through the Public Health Emergency Preparedness (PHEP) cooperative agreement and provides laboratory surge capacity for a public health emergency. The Level 1 LRN-C laboratory in DWRLB provides clinical testing of toxic chemical agents (e.g., including cyanide, nerve agents, mustard agents, metals, toxic industrial chemicals and biotoxins). The clinical testing is conducted using high-throughput, CDC test methods and instrument platforms for reliability, speed and capacity.