A selection of project descriptions:

Lower Truckee Basin Ground Water Study In 1998 PGH was retained by the Desert Research Institute (DRI) in Reno, Nevada to help assess the impact of Fernley Basin irrigation return flow on the lower Truckee River. The Fernley Basin is located about 30 miles west of Reno. The complexity of this project required a team of specialists in ground water modeling, ground water chemistry, geomorphology, stream hydrology, geophysical exploration, engineering, and biology. Plumas Geo-Hydrology was retained to characterize migration of soil salinity into the underlying aquifer and into the river. Irrigation return flow salt load was estimated with a combination of stable isotopes, chloride and sulfate in ground water, serving as conservative tracers. While resolving the initial questions posed by the project’s initiators, deterioration of the Town of Fernley municipal wells as a side effect of decreasing irrigation became an additional issue.

The project team was eventually able to generate a ground water flow and transport model to simulate a number of optional mitigation measures. The study also led to several new insights into evolution of desert basin hydrology in the western Great Basin. Results were presented in a number of scientific publications prepared by project team members.

South Truckee Meadows aquifer water storage and retrieval Aquifer storage and retrieval (ASR) is a method of storing surplus surface water in the winter in an aquifer that has been partially depleted in the preceding high water demand summer season. The temporarily stored water is then available for pumping in the summer season.

In 1997 Plumas Geo-Hydrology was retained by Consulting Engineering Services of Reno (now AMEC) to assist in a passive aquifer storage and retrieval feasibility study of the southern Truckee Meadows, south of Reno, Nevada. The study was conducted for the Washoe County Water Commissioners. About 1500 data sets of domestic and municipal well water chemistry, retrieved from County and State Health Lab records, turned out to be incredibly valuable, allowing reconstructing the aquifer’s response to historic changes in irrigation recharge. The final analysis determined that passive artificial recharge through pond infiltration is a viable option. More so, the data also established a 35 year record of aquifer response to urbanization, showing long term impact from domestic leach fields and other urban activities on ground water quality.

As a follow-up in 1998 Plumas Geo-Hydrology assisted ECO:LOGIC Engineering of Reno, NV in an injection well test to study feasibility of active ASR by analyzing water chemistry, tri-halo methane and environmental isotopes in injection and ground water.

American Valley ground water development and aquifer protection In 1993 Plumas Geo-Hydrology was retained by Quincy Community Services District (QCSD) to develop an aquifer protection program in American Valley (AV), a fault bounded basin located in Plumas County in the northeastern Sierra Nevada of California. This so-called wellhead protection program (WHP) was funded by the US EPA to help demonstrate how aquifer protection can be brought to public attention in a small rural community. A ground water data base was established to identify ground water flow paths and sources of ground water pollution.

From a consultant’s standpoint the task of public education created particular challenges. Initially even QCSD’s governing board, and much less so the local business establishment had trouble accepting the urgency of ground water protection. Eventually several ground water pollution incidents brought the point home, including MTBE contamination in QCSD’s most productive well. More so, a combination of ground water quality problems and urban development turned out to become an increasing constraint on QCSD’s ability to provide a reliable long term water supply.

In 2002 Plumas Geo-Hydrology was retained to identify new well locations. The preceding WHP study helped QCSD obtain a grant from the State Department of Water Resources to drill five exploration wells in 2004 and 2005. While that effort revealed further constraints it also opened up new areas for ground water development in the valley, focusing on drilling wells in the canyons south of the valley. It posed particular challenges in developing ground water in upland fractured bedrock aquifers (shale and metavolcanics).

Geothermal exploration in the Alturas Basin, Modoc County, California In 1988 Burkhard Bohm was retained by Modoc Joint Unified School District to manage drilling a geothermal well in the town of Alturas. Preceding site selection based on shallow well temperature gradients and ground water chemistry data indicated a geothermal aquifer temperature of about 180 F below 2000 ft. Several faults were identified in the Alturas urban area and a drill site was selected on the High School grounds, a few hundred feet east of Main Street. Hot water (180 F) was found in a large fracture at 2440 ft. Although the well initially flowed at 900 gallons per minute the long term sustainable flow was only 35 gpm, as is typical in fractured bedrock wells. Nevertheless, this yield has been adequate to heat the entire High School complex since 1990. A more promising well was drilled under Plumas Geo-Hydrology project management in 1991 about one mile west of the first well, producing about 200 gpm. Unfortunately problems with geothermal effluent disposal have so far hampered utilization of this second well. These two wells proved that the town of Alturas is located on a significant geothermal resource.

Lessons learned from the two Alturas wells were applied in 2001, when Plumas Geo-Hydrology was retained by the I’SOT community in Canby (20 miles west of Alturas) for site selection and drilling project management of a 2100 ft production well. The successful I’SOT well has rekindled the interest in geothermal development at the nearby Canby Hot Springs area.

Other Selected Projects

City of Jackson, Amador County, California: Estimating magnitude of leakage from the Amador Canal in the Jackson Creek Watershed, using environmental isotopes and major ion chemistry.

Lovelock Meadows Water District, Nevada, 1997: Ground water recharge estimate for part of the Humboldt Mountain Range, using hydrogeochemical and environmental isotope data. Subcontract for Consulting Engineering Serves, Reno, NV (Dale Bugenig).

Gold Mountain Ranch, Portola, CA, 1995/96: Ground water exploration in fractured granitic terrain for a 430 home planned community with two golf courses. Identification of drill sites via fracture trace analysis, geophysical exploration and structural geological analysis, and subsequent drilling project management. Preparation of environmental documentation.

Portola Landfill, 2000, City of Portola: Assessment of landfill leachate impacts on ground water in a granitic terrain, using existing well records and water quality data at a municipal landfill near Portola, eastern Plumas County, CA. Assistance in site assessment, upgrading monitoring plans and devising mitigation measures. Subcontract for Pacific Waste Services, Chico.

Urban development impacts on ground water in the Chilcoot Subbasin, Sierra Valley, northeastern California, in anticipation of basin-wide full build-out under County General Plan projections. Pumping test data and historical well water level records analysis in conjunction with isotope and water chemistry data.

Washoe County Utility Division, Reno, NV, 1990: Isotope hydrology of southern Honey Lake Valley, Nevada and California. Hydrologic flow system analysis, inter basin ground water flow and ground water recharge estimates.

Eastern Plumas Health Care Facility, 1999: Phase One Environmental Site Assessment of Hospital Property. Joint project with Ground Zero Analysis, of Escalon, California; conducted for Plumas Bank in Portola.

Wesley's Exxon, Portola, Plumas County, CA, beginning 1995 and still ongoing: project management of underground tank removal on a commercial property and subsequent site characterization. Monitoring well installation, quarterly monitoring and State application of expense reimbursal for client.

Plumas County Flood Control and Water Conservation District: Assessment of baseflow augmentation due to stream channel restoration in the Last Chance and Red Clover Watersheds using environmental tracers. Beginning October 2004 and still ongoing.

City of Lincoln, Placer County, California, 2004: Identification of long term ground water development impacts on upward migration of high TDS ground water from the Chico formation. Under subcontract with ECO:LOGIC Engineering, Reno, Nevada.