Principal Groundwater Geologist


Mr. LaPensee has been a Groundwater Geologist/Hydrogeologist with the firm since 1989. While with the firm he has been involved with the hydrogeologic assessment and analysis of groundwater basins in southern and northern California and the exploration for and development of groundwater in those basins. Mr. LaPensee�s current focus has been on projects involving the development of groundwater in southern California groundwater basins encompassing the siting, design and technical oversight of construction for municipal- and irrigation-supply water wells. In addition, Mr. LaPensee has also provided technical oversight in the siting, design and testing of aquifer storage and recovery (ASR) wells and groundwater monitoring wells for hazardous waste sites.

In order to perform an analysis of groundwater basins and hazardous waste sites, Mr. LaPensee uses several data elements in the evaluation process such as:

  • Geology and hydrogeology.
  • Water-level and water-quality data.
  • Driller�s logs of wells.
  • Surface geophysical surveys (when deemed appropriate).
  • Downhole geophysical surveys (electric logs) and electric log correlation of aquifer systems.
  • Downhole flowmeter (spinner) surveys.

These elements are synthesized in groundwater projects to aid in the selection of suitable well sites and test drilling methods; determine depths of well drilling; outline types of testing to be performed in test hole drilling; select suitable types of well casing and other well construction materials; outline appropriate mechanical, chemical, and pumping development methods; define aquifer testing protocol; formulate groundwater sampling methods using accepted protocol for such contaminants as hydrocarbons, metals, and volatile organic compounds (VOCs), and; estimate key aquifer parameters and production capabilities based on the resulting drilling and testing data.


Senior Groundwater Geologist

Employment position is of Senior Groundwater Geologist with major responsibilities as a project manager directed towards groundwater evaluation, exploration, and development projects. The areas of responsibilities in these projects encompass: preparation of proposals and cost estimates for various types of hydrogeologic projects; preparation of technical specifications for new well projects and well rehabilitation; providing technical and administrative oversight of well drilling and rehabilitation, construction, development, and testing activities on well projects, and; the preparation and completion of final project reports.

Project Geologist
1988 - 1989

Responsibilities encompassed the overview and management of commercial hazardous waste site investigations, including the installation of vadose-zone and groundwater monitoring wells, aquifer testing, and computer data manipulation and modeling of aquifer test data.

Associate Geologist
1987 - 1988

Responsibilities encompassed the assessment and investigation of Federal and California Superfund sites (soil and groundwater), including the installation of groundwater monitoring wells, aquifer testing, geophysical surveying (utilizing ground penetrating radar, electro-magnetic, and resistivity methods), and computer processing and modeling of geophysical data.

Staff Hydrogeologist
1986 - 1987

Responsibilities encompassed site assessment and investigation (soil and groundwater) of commercial and industrial hazardous waste sites. This included the installation of vadose-zone and groundwater monitoring wells, aquifer testing, and computer processing of geophysical data.


LaPensee, E.F., Elders, W.E. and Shannon, S.S., October, 1988; �Implications for U Transport in Groundwater; Trace Element Variations in Sandstones of the Salt Wash Member, Morrison Formation, Around the La Sal Mountains, Utah�: Geological Society of America, 1988 Centennial Meeting, Abstracts with Program, Vol. 20, No. 7, pg. A150.

LaPensee, E.F., & Smith, L.V., 1994, �Groundwater Geology of the Santa Ynez River Valley�, in Groundwater Geology of the Wine Country, Carpinteria and Santa Ynez Valley Region, Santa Barbara County, California. 1994 Field Trip Guidebook for the Coast Geologic Society. E. F. LaPensee and L. V. Smith, Eds.

LaPensee, E. F., Slade, R. C., and Whitten, M.W., September 1994, "Local Groundwater Resources of the Napa Valley": Paper presented at 1994 Groundwater Resources Association Annual Meeting, Napa, California.

LaPensee, E.F. and Slade, R.C., 2000, �How Local Hydrogeologic Conditions Influence Well Design Options�. Paper presented for the American Ground Water Trust/American Water Works Association (California-Nevada Section) titled �Optimizing Use of Ground Water Resources, Focus on Water Supply Wells and Well Design�. Lakewood, California October 19. 2000.

University of California
Los Angeles
B.S., Geology

University of California
M.S., Geological Sciences
1986, Trace-element

Certified Hydrogeologist and Professional Geologist, State of California,
Registered Professional Hydrogeologist, American Institute of Hydrology (AIH)
California Community College Instructor, June 1986