Welcome to the State of California 

Drinking Water and Radiation Laboratory Branch (DWRLB)

Updated:  Nov 15, 2016

DWRLB Branch Chief 

William M. Draper, Ph.D.


Organization Chart

DWRLB Organization Chart 11-15-16


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General Information

DWRLB is California’s primary drinking water quality testing laboratory and is the only State laboratory capable of measuring environmental radiation. Its primary missions are to provide analytical services, reference measurements and technical support to the State’s drinking water program and Radiologic Health Program.  DWRLB also provides emergency public health laboratory services, for example, serving as a surge laboratory for the federal Centers for Disease Control and Prevention (CDC).

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

DWRLB provides drinking water laboratory services to the State Water Resources Control Board’s (SWRCB) Division of Drinking Water’s 22 District Offices through a multiyear contract.  Radiochemistry services are provided to the Radiologic Assessment Unit, the Environmental Management Branch and public health authorities and emergency responders at the local, State and Federal level.

DWRLB has a single laboratory in Richmond and is organized into two sections: the Chemistry & Radiochemistry Section and the Microbiology & Biomonitoring Section.  Within these Sections are four units: the Chemistry Unit (analyzing water for inorganic and organic chemical contaminants), the Radiochemistry Unit (analyzing environmental radioactivity and radionuclides in various media including drinking water), the Biomonitoring Unit (analyzing clinical specimens for toxic chemicals) and the Microbiology Unit (providing environmental microbiology services, including analysis of drinking water).    

Certificates, Licenses and Memberships

DWRLB laboratory services are conducted in accordance with a variety of quality assurance programs and schemes including auditing and certifications by the U. S. Environmental Protection Agency (U. S. EPA).  The DWRLB clinical laboratory participates in federal CDC’s quality assurance program according to Clinical Laboratory Improvement Amendments (CLIA) guidelines and is a California-licensed clinical laboratory.  DWRLB is a member of U. S. EPA’s Emergency Laboratory Response Network (ERLN) and the Water Laboratory Alliance (WLA).  DWRLB certifications and licenses are provided in links: 

USEPA Chemical Analysis Certificate.pdf

USEPA Microbiology Certificate.pdf

USEPA Radiochemical Analysis Certificate.pdf

California Clinical Laboratory License.pdf

CLIA Certificate of Registration.pdf

LRN-C Proficiency Testing Pgm.pdf

USEPA ERLN Membership.pdf


Chemistry & Radiochemistry Section (CRS). Dr. Raimund Roehl, Section Chief                 

Chemistry Unit (CU).   Dr. Dadong Xu, 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).  An extensive list of approved test methods is provide below under Methods and Services.

Radiochemistry Unit (RCU).   Dr. Shiyamalie Ruberu, Unit Supervisor 

The Radiochemistry Unit (RCU) of DWRL is the only State laboratory capable of conducting radiological testing on environmental samples.  RCU identifies and quantitates naturally occurring and man-made radionuclides in environmental samples such as water, air, soil, sediment, milk, vegetation, and biotas.  The Unit determines drinking water compliance with the Safe Drinking Water Act regulations; supports the Radiologic Health Branch in monitoring environments surrounding the three  nuclear power plant sites in California (San Onofre, Diablo Canyon, Humboldt Bay), and conducts enforcement/compliance monitoring of facilities that use radioactive materials;  supports the Environmental Management Branch in the decommissioning/decontamination of former military sites (Hunters Point Shipyard, Treasure Island, McClellan AFB, Alameda NAS) and participates in California’s Nuclear Power Plant Emergency Response Program

Microbiology & Biomonitoring Section (MBS).  Dr. James Chithalen, Section Chief          

Microbiology Unit (MU).  [Vacant], 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 Giardia and Cryptosporidium.  This work, in collaboration with local public health departments, EMB and other CDPH labs relies on new 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.

Biomonitoring Unit (BU).  Dr. Wenlu Song, Unit Supervisor

The Biomonitoring Unit within DWRL 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.  


DWRLB relies on and supports various public health partners including:

CDPH Radiologic Health Branch

CDPH Environmental Management Branch

CDPH Emergency Preparedness Office

US Centers for Disease Control & Prevention

CA State Water Resources Control Board: Division of Drinking Water

CA State Water Resources Control Board: ELAP

U.S. Environmental Protection Agency

Association of Public Health Laboratories

Local Public Health Departments           

Methods and Services

DWRLB offers a variety of approved laboratory test procedures listed in the following links:

DWRLB Chemistry Methods 2016.pdf

DWRLB Radiochemistry Methods 2016.pdf

DWRLB Microbiology Methods 2106.pdf

LRN-C Clinical Laboratory Methods 2016 Brief.pdf

Submission Instructions and Forms

DWRLB Sample Analysis Request Form.pdf

DWRLB Sample Analysis Request Form Radiochemistry.pdf


Scientific Publications/Presentations

DWRLB Scientific Publications and Presentations.pdf


Contact DWRLB:

Phone: (510) 620-2911

Fax: (510) 620-2940

Mailing Address:

California Department of Public Health

Drinking Water & Radiation Laboratory Branch

850 Marina Bay Parkway, MS G-164

Richmond, CA 94804-6403

Last modified on: 11/15/2016 9:58 AM