Phillip D Hays
Science and Products
Ground-Water Modeling Support - Arkansas
Short Title: North Ground-Water Model
Project Chief: Phillip Hays
Cooperators: Arkansas Natural Resources Commission
Project Time Frame: 2005 - present
Several counties in eastern and southern Arkansas have been designated Critical Ground-Water Areas (areas where alluvial aquifer...
A Method for Identifying Karst Features in the Ozarks and Their Correlation to Ground-Water Quality Impacts
Short Title: Ozark Karst Study
Project Chiefs: Tim Kresse (USGS-Water), Phil Hays (USGS-Water), James Kaufmann (USGS-Geography), Mark Hudson (USGS-Geology), Esther Stroh (USGS-Biology)
Cooperator: U.S. Geological Survey
Project Time Frame: 2007 - 2011
Three major physiographic provinces in the Ozark Plateaus in Arkansas and Missouri include diverse topography and...
Preliminary Characterization of Thermal Waters East of Hot Springs National Park - Arkansas
Short Title: Hot Springs Thermal Study
Project Chief: Tim Kresse
Cooperators: Arkansas State Highway and Transportation Department
Project Time Frame: 2007 - 2009
Established in 1832 to preserve 47 hot springs flowing from of Hot Springs Mountain, Hot Springs National Park (HSNP) is the oldest National Park in the...
Phosphorus runoff risk assessment in karstic regions of the U.S.
The Phosphorus (P) Index risk assessment tool has been widely adopted across the U.S. to identify and rank site vulnerability to P runoff as part of the Natural Resources Conservation Service (NRCS) nutrient management planning (NMP) process. However, limited success has been achieved in addressing the risk of P loss by subsurface flow pathways,...
Sharpley, Andrew N.; Hays, Phillip D.; Daniels, Michael B.; VanDevender, Karl W.Potentiometric surface of groundwater-level altitudes near the planned Highway 270 bypass, east of Hot Springs, Arkansas, July–August 2017
The Ouachita Mountains aquifer system potentiometric-surface map is one component of the Hot Springs Bypass Groundwater Monitoring Project. The potentiometric-surface map provides a baseline assessment of shallow groundwater levels and flow directions before the construction of the Arkansas Department of Transportation planned extension of the...
Nottmeier, Anna M.; Hays, Phillip D.Encylopedia of Caves
For many people, a visit to a cave is a wondrous event directing our minds to ponder the mysteries presented by these unique places and inspiring questions: How old is the cave? What was the role of water in forming the cave and where did the water come from? How is the cave connected to the surface environment? These are intriguing questions to...
Knierim, Katherine J.; Hays, Phillip D.Coupling high-frequency stream metabolism and nutrient monitoring to explore biogeochemical controls on downstream nitrate delivery
Instream biogeochemical process measurements are often short-term and localized. Here we use in situ sensors to quantify the net effects of biogeochemical processes on seasonal patterns in baseflow nitrate retention at the river-reach scale. Dual-station high-frequency in situ nitrate measurements, were coupled with high-frequency measurements of...
Jarvie, Helen P.; Sharpley, Andrew N.; Kresse, Timothy M.; Hays, Phillip D.; Williams, Richard J.; King, Stephen M.; Berry, Lawrence G.Carbon cycling in the mantled karst of the Ozark Plateaus, central United States
The nature of carbon (C) cycling in the unsaturated zone where groundwater is in contact with abundant gas-filled voids is poorly understood. The objective of this study was to trace inorganic-C cycling in a karst landscape using stable-C isotopes, with emphasis on a shallow groundwater flow path through the soil, to an underlying cave, and to the...
Knierim, Katherine J.; Pollock, Erik D.; Covington, Matthew D.; Hays, Phillip D.; Brye, Kristofor R.Hydrogeology and hydrologic conditions of the Ozark Plateaus aquifer system
The hydrogeology and hydrologic characteristics of the Ozark Plateaus aquifer system were characterized as part of ongoing U.S. Geological Survey efforts to assess groundwater availability across the Nation. The need for such a study in the Ozark Plateaus physiographic province (Ozark Plateaus) is highlighted by increasing demand on groundwater...
Hays, Phillip D.; Knierim, Katherine J.; Breaker, Brian K.; Westerman, Drew A.; Clark, Brian R.Altitudes and thicknesses of hydrogeologic units of the Ozark Plateaus aquifer system in Arkansas, Kansas, Missouri, and Oklahoma
A hydrogeologic framework was constructed to represent the altitudes and thicknesses of hydrogeologic units within the Ozark Plateaus aquifer system as part of a regional groundwater-flow model supported by the U.S. Geological Survey Water Availability and Use Science Program. The Ozark Plateaus aquifer system study area is nearly 70,000 square...
Westerman, Drew A.; Gillip, Jonathan A.; Richards, Joseph M.; Hays, Phillip D.; Clark, Brian R.Trace-metal and organic constituent concentrations in bed sediment at Big Base and Little Base Lakes, Little Rock Air Force Base, Arkansas—Comparisons to sediment-quality guidelines and indications for timing of exposure
This report compares concentrations for a wide range of inorganic and organic constituents in bed sediment from Big Base Lake and Little Base Lake, which are located on Little Rock Air Force Base, Arkansas, to sediment-quality guidelines. This report also compares trace-metal concentrations in a bed-sediment core sample to sediment age to...
Justus, B.G.; Hays, Phillip D.; Hart, Rheannon M.Using stable isotopes of carbon to investigate the seasonal variation of carbon transfer in a northwestern Arkansas cave
Stable-isotope analyses are valuable in karst settings, where characterizing biogeochemical cycling of carbon along groundwater flow paths is critical for understanding and protecting sensitive cave and karst water resources. This study quantified the seasonal changes in concentration and isotopic composition (δ13C) of aqueous and gaseous...
Knierim, Katherine J.; Pollock, Erik; Hays, Phillip D.; Khojasteh, JamAquifers of Arkansas: protection, management, and hydrologic and geochemical characteristics of groundwater resources in Arkansas
Sixteen aquifers in Arkansas that currently serve or have served as sources of water supply are described with respect to existing groundwater protection and management programs, geology, hydrologic characteristics, water use, water levels, deductive analysis, projections of hydrologic conditions, and water quality. State and Federal protection...
Kresse, Timothy M.; Hays, Phillip D.; Merriman, Katherine R.; Gillip, Jonathan A.; Fugitt, D. Todd; Spellman, Jane L.; Nottmeier, Anna M.; Westerman, Drew A.; Blackstock, Joshua M.; Battreal, James L.Geochemical and isotopic variations in shallow groundwater in areas of the Fayetteville Shale development, north-central Arkansas
Exploration of unconventional natural gas reservoirs such as impermeable shale basins through the use of horizontal drilling and hydraulic fracturing has changed the energy landscape in the USA providing a vast new energy source. The accelerated production of natural gas has triggered a debate concerning the safety and possible environmental...
Warner, Nathaniel R.; Kresse, Timothy M.; Hays, Phillip D.; Down, Adrian; Karr, Jonathan D.; Jackson, R.B.; Vengosh, AvnerUsing isotopes of dissolved inorganic carbon species and water to separate sources of recharge in a cave spring, northwestern Arkansas, USA Blowing Spring Cave
Blowing Spring Cave in northwestern Arkansas is representative of cave systems in the karst of the Ozark Plateaus, and stable isotopes of water (δ18O and δ2H) and inorganic carbon (δ13C) were used to quantify soil-water, bedrock-matrix water, and precipitation contributions to cave-spring flow during storm events to understand...
Knierim, Katherine J.; Pollock, Erik; Hays, Phillip D.