Groundwater chemistry in the vicinity of the Puna Geothermal Venture Power Plant, Hawai‘i, after two decades of production

Abstract

For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit http://www.usgs.gov/ or call 1-888-ASK-USGS (1-888-275-8747).For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod/.Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.Suggested citation: Evans, W.C., Bergfeld, D., Sutton, A.J., Lee, R.C., and Lorenson, T.D., 2015, Groundwater chemistry in the vicinity of the Puna Geothermal Venture power plant, Hawai'i, after two decades of production: U.S. Geological Survey Scientific Investigations Report 2015-5139, 26 p., http://dx.doi.org/10.3133/sir20155139. ISSN 1995, 1998, 2000, 2001, 2004, and 2007-14 Datum• Vertical coordinate information is referenced to the North American Vertical Datum of 1983 (NAD83).• Horizontal coordinate information is referenced to the North American Vertical Datum of 1983 (NAD83).• Altitude, as used in this report, refers to distance above the vertical datum. Supplemental Information• Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25 °C).• Concentrations of chemical constituents in water are given in either milligrams per liter (mg/L), micrograms per liter (µg/L), or micromoles per kilogram (µmol/kg), where a kilogram of water is nearly equal to a liter.• Concentrations of chemical constituents in gas are given in either volume percent or in parts-per-million by volume.• AbstractWe report chemical data for selected shallow wells and coastal springs that were sampled in 2014 to determine whether geothermal power production in the Puna area over the past two decades has affected the characteristics of regional groundwater. The samples were analyzed for major and minor chemical species, trace metals of environmental concern, stable isotopes of water, and two organic compounds (pentane and isopropanol) that are injected into the deep geothermal reservoir at the power plant. Isopropanol was not detected in any of the groundwaters; confirmed detection of pentane was restricted to one monitoring well near the power plant at a low concentration not indicative of source. Thus, neither organic compound linked geothermal operations to groundwater contamination, though chemical stability and transport velocity questions exist for both tracers. Based on our chemical analysis of geothermal fluid at the power plant and on many similar results from commercially analyzed samples, we could not show that geothermal constituents in the groundwaters we sampled came from the commercially developed reservoir. Our data are consistent with a long-held view that heat moves by conduction from th...

Officially social: Developing a social media crisis communication strategy for USGS Volcanoes during the 2018 Kīlauea eruption

“…During the eruption, parts of PGV were inundated by lava, and it was determined that its geothermal wells needed to be filled, capped, and sealed. Additionally, chemicals stored onsite for geothermal well operations (n-pentane, a common additive to reduce the boiling point of water injected into wells; Evans et al, 2015) were removed, but not immediately. The Environmental Protection Agency cited PGV for hydrogen sulfide releases in 2013 (Higuchi, 2016), and residents were generally suspicious of the plant, including whether PGV activities had triggered fissure eruptions.…”

3D electrical conductivity tomography of volcanoes

“…27. In this figure, the range of conductivity of the pore waters in t upper of Kiluea are from McMurtry et al (1977), Tilling and Jones (1991), and Evans et al (2015) with a typical range of pore water conductivity between 1 × 10 −2 to 2.6 S m −1 (pH between 7.6 and 8.7).…”