Staff Resumes

Herzog Geotechnical personnel have extensive experience in the Bay Area. Detailed resumes for our key members are presented below. The team has completed numerous large and complex projects, and has earned a reputation for quality work completed on time and on budget. Below is a brief description of key personnel.

Craig Herzog, Principal Engineer

Mr. Herzog, Registered Geotechnical Engineer, acts as Project Manager and is responsible for day to day coordination of projects, and the performance of engineering analyses. His experience includes landslide evaluation and repairs, seismic risk and site response analysis, liquefaction analysis, horizontal drilling and jacked pipe construction, lateral support systems, settlement analysis, deep foundations, and computer applications for geotechnical design. (more)

H. Donald Herzog, Senior Geotechnical Consultant

Mr. Herzog, a Registered Geotechnical Engineer with over 30 years experience, provides consultation, quality control, expert witness services and final review. He has managed, supervised and performed geotechnical services for a wide range of public and private projects in the western United States and the South Pacific. He has worked with construction companies on the BART Transbay Tube and the Embarcadero Center, and is experienced with construction feasibility requirements.(more)

Donn Ristau, PhD, Principal Geologist

Dr. Ristau, Certified Engineering Geologist, has over 18 years experience as an engineering geologist. His background includes slope stability analyses and geohazard studies for siting geothermal wells, power plants and road alignments as well as extensive experience in geologic hazard analysis for hillside, residential and commercial developments. In addition, Dr. Ristau is performing seismic risk evaluations for the California Division of Mines and Geology as part of their hospital and school site review program. (more)



Principal Engineer







Senior Geotechnical Consultant







Engineering Geologist


•  University of California, Davis; Ph.D. Geology, 1977

•  University of California, Davis; M.S. Geology, 1973

•  California State University, Northridge; B.S. Geology, 1970


•  California Registered Geologist, 1981, RG 3634

•  Certified Engineering Geologist, 1983, CEG 1155


•  OSHA 40 Hour Hazardous Waste Activities Training


1991-Present Phoenix Geotechnical, Napa, CA; Principal Engineering Geologist/Owner

1982 - 1991 Herzog Associates, Napa, CA; Senior Engineering Geologist

1980 - 1982 Harding Lawson Associates, Inc., Novato, CA; Senior Geologist

1980 Independent Consultant - US Forest Service

1978 - 1980 California Department of Forestry, Santa Rosa, CA; Assistant Geologist


Dr. Ristau has 18 years experience in project management for environmental geology and engineering geology studies directly related to the scope of work outlined in the RFP. He has been involved as the lead geologist for geologic, landslide mapping and fault identification studies for engineering geology/geohazard investigations for large subdivisions, commercial properties, major roadway improvements and landfills. In the past 16 years as a geotechnical consultant, he has conducted or participated in numerous EIR and geotechnical investigations for public, commercial and industrial developments which have included slope stability and liquefaction analysis, fault location studies/seismic risk analysis, and geotechnical hazard evaluations. He has developed both deterministic and probabilistic seismic risk assessments for EIR's for roadway development projects in areas of unstable fill and bay mud deposits and for large subdivisions in the San Francisco Bay area. His background includes slope stability analyses and geohazard studies for siting geothermal wells, power plants, and road alignments, as well as extensive experience in geologic hazard analysis for hillside, residential and commercial developments. He has provided hydrogeologic analysis related to the potential for groundwater production and development for private residential developments, as well as serving as a review consultant for City/County agencies. He has been involved as the primary geologic consultant for investigations of confirmed fuel release sites in the Santa Clara Valley, as well as being lead geologist for a major landfill siting study and a major hydrogeologic study of an existing landfill site.


•  UNION PACIFIC EXPERT WITNESS, Oroville, CA - Evaluation of causation of landslide risk assessment related to slope stability along railroad alignment.

•  GEOLOGIC AND LANDSLIDE DATA BASE COMPILATION, California Department of Forestry Region 1 and U.S. Forest Service, Northern California - Landslide inventory and geologic mapping/air photo interpretation. Mapping used to delineate geologic hazards related to logging activities and development of mitigation for control of sediment point sources.

•  GEOTHERMAL POWER PLANT AND WELL PAD INVESTIGATION, The Geysers, Sonoma County, CA - Geotechnical and geohazards investigation to facilitate design and construction of 5 well pads, 2 power plants and access roads. Special emphasis was placed on road construction, stabilization of slides and providing erosion control measures for graded areas.

•  SERPAS RANCH, Fairfield, CA - Geologic investigation for a proposed 400 unit subdivision. The main geotechnical concern evaluated involved the presence of landslides within and adjacent to areas of proposed construction.

•  SHARP PARK ROAD, Pacifica, CA - Design recommendations for construction of a major roadway improvement involving cut and fill grading and retaining wall construction.

•  DEL MADERA SUBDIVISION, Tiburon, CA - Landslide hazard mitigation and geologic engineering for major subdivision on unstable hillside.

•  STRAWBERRY VISTA, Marin County, CA - Geotechnical investigation for 75 unit subdivision with emphasis on landslide hazard mitigation and site development.

•  SKYWALKER RANCH GEOHAZARDS INVESTIGATION, Marin County, CA - Geologic landslide mapping and mitigation of geologic hazards.

•  EDUCATIONAL FACILITIES, Alameda/Contra Costa/Napa/Lake County, CA - Provided geohazards evaluation in compliance with Title 22 requirements for proposed school and critical facilities additions. Analyses included probabilistic seismic risk assessment and liquefaction analyses, as well as fault location trenching studies.

•  EXPERT WITNESS, Marin, Solano and San Francisco Counties, CA - Performed geotechnical investigations and developed expert opinions for causation, risk assessment and mitigation of landslide related litigation.

•  GEOTECHNICAL REVIEW CONSULTANT, City of San Rafael, Town of Tiburon, Napa County, Marin County and Sonoma County.

•  ALASKAN PIPELINE TERMINAL FACILITY, Valdez, AK - Offshore geologic hazards assessment and geophysical study for proposed terminal complex.

•  PRUDHOE BAY DEVELOPMENT, Deadhorse, AK - Geotechnical engineering for construction of an offshore oil drilling islands.

•  CITY OF VALLEJO ROADWAY EIR, Vallejo, CA - Preparation of geotechnical element of the EIR for construction of roadway near Mare Island, in area of unstable fill/bay mud deposits.

•  NAPA OAKS EIR, Napa, CA - Preparation of geohazards analysis for large (99 lot) subdivision for use in EIR review. Primary emphasis on fault identification and evaluation of existing fill deposits.

•  LARKSPUR QUARRY EIR, Larkspur, CA - Preparation of EIR geotechnical element and geohazards evaluation for large condominium development in old quarry. Primary emphasis on slope stability and site grading.

•  IBM, San Jose, CA - Soil contamination and groundwater monitoring survey.

•  PALOS VERDES LANDFILL, Palos Verdes, CA - Lead geologist for a hydrogeologic investigation of an existing landfill with respect to evaluating the potential for off-site migration of landfill leachate.

TOWSLEY CANYON LANDFILL, Los Angeles, CA - Lead geologist for geologic and landslide mapping, borrow investigation, access road evaluation, and seismicity evaluation at a major southern California proposed landfill site. Emphasis placed on air photo mapping of lithology, structure and slope stability conditions in inaccessible terrai




home | contact Herzog Geotechnical 2005