USGS Regional Assessment of the Floridan System: Updating the hydrogeologic framework and underlying hydrologic databases that are being used for future modeling efforts

Prepared for the South Hydrologic Society Lester J. Williams and Joe D. Hughes 4/18/2011 U.S. Department of the Interior U.S. Geological Survey Presentation Outline

ƒ Give you overview of project background (issues) and objectives ƒ Databases and Framework ƒ Hydrogeologic Framework ƒ Database Development ƒ Long-term hydrologic records ƒ Springs and SW Inventory ƒ Potentiometric Map ƒ Water-Use Data Compilation ƒ Model Development Finchs Cave, Marion Co. FL ƒ SWI Development (Joe) (Photo: A.M. Cressler) Project Background

ƒ One of several current ongoing studies being conducted by the USGS Resource Program (GWRP) ƒ Began in Fall of 2009 ƒ Project team members located across Southeastern U.S. ƒ Several previous meetings have been held between USGS and local districts and states to keep folks apprised of developments and important results USGS Regional Assessments

ƒ A key role of national and regional assessments is to provide consistent and integrated information across political boundaries that is useful to those who use and manage the resource.

U.S. Geological Survey Circular 1323 (Published July 2008) USGS Water Resource Program

Goal: National Assessment of Groundwater Availability

Floridan Aquifer System

30 principal account for 94% of total groundwater withdrawals Current or Completed Studies Floridan Aquifer System

ƒ Underlies an area of about 100,000 square miles ƒ Groundwater withdrawals Challenges: averaged 3,640 -large geographic area Mgal/day in -fairly complex 2000 -multiple water agencies responsible for collecting data Issues

ƒ One of the major issues for the region is an increased need for freshwater supplies Issue: Flows and Levels

From: USGS SIR 2009 5046 (Walsh, Knowles, Katz, Strom) Long-Term Trends in Springs

Fanning Springs Levy County, FL Relation to Relative Degree of Confinement Rate of decline Degree of Confinement ƒ Long-term (40-yr) average rate of decline is 3 times greater in the confined areas vs. unconfined areas Declining Areas in Relation to Magnitude 1 and 2 Springs

Average 10-yr Decline Rate 1970 to 2010

“i.e. every 10 years we loose …xx ft” Issue: Salt Water Intrusion Project Objectives:

ƒ Quantify current ground-water resources ƒ Evaluate how these resources have changed over time ƒ Provide tools to forecast system responses to stresses from future human and environmental uses Project Objectives:

ƒ Quantify current ground-water resources ƒ Evaluate how these resources have changed over time ƒ Provide tools to forecast system responses to stresses from future human and environmental uses Schedule of Major Work Activities Hydrogeologic Framework Revision RASA ƒ Focus on improving the Framework physical geometry and understanding of the 6 to 8 yrs hydraulic properties of the system ƒ Improve understanding New of flow system needed to Framework build numerical model ƒ Active surficial ƒ Salt-water encroachment 2 yrs The Floridan Aquifer System

ƒ Confined and unconfined areas ƒ Most areas we have permeable carbonate rocks confined above and below by low- permeability sediments ƒ Further subdivided into upper and lower aquifers Relative Degree of Confinement

ƒ Large amounts of recharge in the unconfined or thinly confined areas of the system

Modified from Bush and Johnson, 1988 Aquifers and Confining Units

Upper Confining Unit Upper Floridan Aquifer Middle Confining Unit Lower Floridan Aquifer Floridan Framework (our focus) Aquifers and Stratigraphy Confining Units

ƒ Cretaceous System ƒ ƒ Tertiary System ƒ Upper Confining Unit** ƒ Series ƒ Floridan Aquifer ƒ Eocene Series System ƒ Oligocene Series ƒ Extent* ƒ Miocene Series ƒ Top of System* ƒ Post Miocene ƒ Upper Floridan* ƒ Middle Confining Unit** ƒ Lower Floridan* Will not be revised ƒ Lower Confinement *Minor revision **Major revision Revised Hydrogeologic Framework

Major Update

ƒ Middle confining units ƒ Extent of each one ƒ Configuration of top ƒ Thickness of units ƒ High T Zones ƒ APPZ, FPZ, BZ ƒ Location of freshwater/saltwater Interface Middle Confining Unit I

ƒ Low-permeability zone mostly within rocks of middle Eocene age extending from to Florida Keys ƒ Separates the Upper and Lower Floridan aquifers ƒ Overlaps gypsiferous dolomite of MCU II MCU I: Geologic Units and Lithology ƒ Mostly located in the middle and upper parts the middle Eocene ƒ Locally lower part of the Very Late Eocene local ƒ Soft micritic limestone and fine-grained mostly dolomitic limestone, here both of low ƒ Original porosity not greatly affected by pore filling minerals MCU I: Confining Properties

ƒ Leakiest of all MCUs ƒ Lithology similar to rocks above and below ƒ Minor head differences and water- quality changes suggests acts as a confining bed Leak-o-meter MCU I: Configuration and Thickness

Top of MCU I ƒ Generally dips modified from along Miller, 1986 stratigraphic horizons ƒ Thickest in southeastern embayment and east-central Florida MCU I: Geophysical Log Characteristics

Focused (guard) ƒ High Gamma Ray Resistivity resistivity ƒ Low porosity ƒ Multiple beds may comprise this unit

Waycross, GA MCU I Mapping Criteria

ƒ Lithology ƒ Geophysical log response (low porosity beds) ƒ Position in stratigraphic section ƒ Top of unit is usually picked on the shallowest low- porosity bed in middle Eocene rocks Brunswick, GA MCUI (Miller, 1986) Middle Confining Unit II

ƒ Low-permeability gypsiferous dolomite and dolomitic limestone ƒ Overlapped by MCU I in part of central Florida ƒ Extensive middle Eocene sabkha or tidal flat MCU II: Geologic Units and Lithology ƒ Located in the middle part of the middle Eocene ƒ Dolomite and dolomitic limestone

ƒ Intergranular here gypsum makes it a very low- permeability unit MCU II: Confining Properties

ƒ Non-leaky confining bed ƒ Mineralized water contained in the unit suggests poor connection with freshwater in the overlying Upper Floridan aquifer Leak-o-meter Configuration Top of MCU II and Thickness modified from Miller, 1986 ƒ Generally dips along stratigraphic horizons ƒ Thickest in the northeast and thins to east ƒ (anomalous thickness in northern Polk) MCU II: Geophysical

Log Characteristics Induction ƒ Identified on elogs by its E-Log Sonic “spiky” high and low resistivity zones ƒ Has very Low porosity (<10%) Upper Floridan

900 MCU II 1300 Lower Floridan Citrus Co. FL Correlation

ƒ Oil and gas test well (Citrus Co.) on left ƒ ROMP core hole (Sumter Co.) on right ƒ These wells are 33 miles apart MCU II Mapping Criteria

ƒ Lithology (evaporites) ƒ Geophysical log response (resistivity and porosity logs) ƒ Position in stratigraphic section ƒ Top of unit is usually

picked at first MCU II occurrence of persistent evaporites Digital Framework

ƒ RASA datasets have been digitized!

Digitized by Jason Bellino, Tampa Digital Data Series Report of RASA datasets

Includes: Bush and Johnson, 1988 Miller, 1986 http://pubs.usgs.gov/ds/584/ Revised Framework 1 ƒ Yellow, basically 3 done 6 ƒ Updated MCUs 2 ƒ Updated Upper Confining Unit ƒ Updated Base of 4 System ƒ Blue, in progress 5 Northern Coastal Region

ƒ During original RASA few wells were used to map permeability variations in the Floridan Aquifer system ƒ “State Line Fault” between Georgia and South Carolina ƒ Capacity use area (restrictions on additional groundwater supply) ƒ Up dip clastic equiv. aquifers Hydrogeologic Framework Progress

ƒ Completed a revised framework for northern coastal region of Georgia and parts of South Carolina ƒ Acknowledgments ƒ Drennan Park , Joe Gillici, Connie Gawne (SC DNR) ƒ Camille Ransom (SC DHEC) ƒ Fred Falls (USGS, SC) ƒ Harold Gill (USGS, Ret.) U.S. Geological Survey SIR 2010-5158 (Published May 2010) Northern Coastal Region of Georgia and Parts of South Carolina ƒ Lot of issues with respect to the placement of the middle confining unit ƒ Had to heavily rely on flowmeter tests

Revised Framework

Original Framework Hydrogeologic Framework Progress

ƒ Extended the Northern Coastal Region new framework into the Ft. Stewart southeastern Georgia coastal plain Wayne ƒ Identified key geophysical Waycross markers in Avon Brunswick Park/Oldsmar

Key test hole St. Marys

Northeastern Florida Northeast Florida/Southeastern Georgia Revisions (cont.)

NWFWMD

ƒ Jeff Davis with SJRWMD SRWMD provided HUGE amounts of SJRWMD experience and data to us.

ƒ Don Boniel with SJRWMD SWFWMD ƒ Rick Spechler provided insights into the Fernandina Permeable Zone and hydrogeology of region SFWMD ƒ Interest Group Presentation, April 2011 Site Location Map Showing Wells Used in Revising Framework Key Well Site: Test Well 26 Colonels Island Hydrogeologic Units ƒ Upper Confining Unit ƒ Upper Floridian Freshwater Aquifer ƒ Lower Floridan Aquifer ƒ Fernandina Freshwater Permeable Zone High Sulfate

Saltwater Middle Confining Units in the Floridan Aquifer System Ware Co. GA: Waycross Test Hole WaycrossTest well

Focused (guard) Gamma Ray Resistivity

MCU I

Logs from files of the USGS

Denotes a geophysical marker bed Lower marker beds below MCU I

marker beds (dolostone)

Logs from files of the USGS Nassau Co. FL: Fernandina Beach Nassau County FL

Focused (guard) Long and Short Resistivity Gamma Ray Normal

MCU I (lower marker beds)

Logs from files of the USGS Correlation DD’56 miles

Waycross, GA Fernandina Beach, FL Acoustic Televiewer Images

ƒ Collected by USGS in the late 1970’s to mid 1990’s ƒ These were scanned in from original Polaroid images ƒ Show a 360 degree oriented image of the inside of the open portion of the borehole

Stitched together Polaroids of ATV image from test well in Brunswick, GA Televiewers Dip direction Projected image on 2-D plane Projected view Core of borehole wall view (wrapped) ATV Images: Brunswick TW-26 Colonels Island, Brunswick GA Solution Zones in the Avon Park Formation Characteristics of solution zones in Avon Park Formation

ƒ Appear to be formed preferentially along dolostone or dolomitic limestone intervals ƒ Each solution zone consists of many individual pipes and openings ƒ Zones of solution openings range from few feet to several 10’s of feet Solution Zones in the Oldsmar Formation Fractures

ƒ Very few observed in ATV images ƒ Most are observed in the cavernous zones possibly associated with collapse? ƒ Relative absence of fracturing in ATV images suggest that vertical fracture systems must be widely spaced or more related to collapse Fracture features described by others working in area Conceptual Model

ƒ As water is pumped from the conduit systems leakage is induced from adjacent confining beds or from intersecting vertical fractures Revised Conceptual Model of Flow Sources of Salt Water

ƒ Trapped connate water inside confining beds ƒ Saline aquifers near base of system Cross Sections

ƒ Deep water test wells ƒ Oil test wells Southeastern ƒ Some of the older Georgia oil test wells were Embayment the best for correlating across the full thickness of aquifer North-South Section East-West Section Hydrogeologic Framework Progress Georgia

Fernandina

Jacksonville

Central and South Florida Central and South NWFWMD Florida SRWMD

SJRWMD ƒ The formations comprising the aquifer thicken dramatically to the south SWFWMD ƒ Thickest part of the FAS is in South Florida Basin ƒ Brackish and saline portions of the aquifer SFWMD ƒ Highly permeable zones ƒ Avon Park Permeable Zone (APPZ) ƒ Boulder Zone (BZ) ƒ Hydrogeologic units from north to south have some differences in how represented in literature South Florida NWFWMD

SRWMD

ƒ Ron Reese and Emily SJRWMD Richardson’s framework

of the APPZ being SWFWMD incorporated ƒ We have a preliminary meeting to discuss SFWMD south Florida framework this week.

Sub-Regional Framework Approach

ƒ Deep injection wells and exploratory well reports ƒ Geophysical logs ƒ Aquifers ƒ Confining units ƒ Transmissive zones ƒ Aquifer Tests ƒ Head Gradients ƒ Cross Sections!!! Basis for all my interpretations

next slide Reported Duncan and “fractured others zones zone”

Pre-existing top markers

Low-porosity unit interpreted from geophysical logs

Water quality change Marked up log

ƒ Interpreted position of the confining units marked on logs ƒ Other notations included ƒ Then transferred to hand-drawn cross sections

Why Cross Sections?

ƒ Main reason is to enable us to build a 3D framework ƒ Continuity of confining beds and permeability variations can be better understood ƒ Very thick system with many different permeable zones and confining beds 3D Geologic Model Database Development

ƒ Geared toward long-term hydrologic records ƒ Groundwater levels ƒ Streamflow ƒ Springflow and pool levels ƒ Hydrologic Properties ƒ T, S, etc… ƒ Hydrogeologic Data (tops) Types of data Sources of data ƒ Water levels ƒ US Geological Survey ƒ continuous ƒ Florida Geological Survey ƒ periodic ƒ Georgia Geological Survey ƒ Chlorides ƒ Geological Survey of ƒ Aquifer performance tests ƒ Precipitation ƒ Florida’s Water Management ƒ Temperature Districts ƒ Geophysical ƒ Consultants data reports ƒ Other ƒ Florida Oil & Gas Board ƒ ƒ FDEP ƒ springs ƒ South Carolina DHEC ƒ water use ƒ … Data Requests Flow Records Groundwater Levels NWFWMD

SRWMD

ƒ NWFWMD (received, thank you!) SJRWMD ƒ SRWMD (received, thank you!) SWFWMD ƒ SJRWMD (received, thank you!) ƒ SWFWMD (received, thank you!) SFWMD ƒ SFWMD (received, thank you!)

Geophysical Logs TDS and Chloride Data Lithology Hydraulic Properties Database

ƒ Databases from ƒ Robert Peterson (SWFWMD ) ƒ Emily Richardson (SFWMD ƒ Chris Richards (NWFWMD) ƒ Dale Jenkins (SRWMD) ƒ David Toth (SJRWMD) ƒ Cross-referenced all databases ƒ Added USGS data -Transmissivity -Storage ƒ Removed duplicates -Leakance ƒ Checked references APTs and Packer Tests ƒ 2,741 test values across study area Potentiometric Map Database

ƒ Model Input May 1980 ƒ Compare regional changes over time ƒ Comparison to pre-development surfaces May 1985 ƒ Groundwater divides Groundwater Levels

ƒ Water-level database Water-Level Tables for developed Floridan Project Database ƒ Model Input ƒ 33,500 wells across study area ƒ 12,387,226 daily values (October 1930 through Early 2010) Groundwater-level Analysis

ƒ Long-term trends ƒ Aquifer system response Well Cluster Sites to hydraulic events ƒ Vertical gradients ƒ Evaluating relative degree of confinement across MCUs ƒ Observation points for model Saline Water Aquifer Mapping Project

ƒ This is a separate study funded through Office of Groundwater (OGW) Freshwater ƒ Began Oct. 2009 ƒ Conducting well-log analysis Transition to determine salinity variations in deep part of Floridan and underlying saline aquifers Salt Water ƒ Work is being conducted parallel to the Floridan Aquifer System modeling effort Geophysical Log Database Development ƒ Compiled well log data from: ƒ 479 wells in FL ƒ 13 wells offshore ƒ 111 wells in GA ƒ Acknowledgments ƒ Dave Taylor (FL Oil and Gas, FDEP) Status as of ƒ Steve Walker (GA Sept. 2010 EPD) Log Analysis: more model input!

ƒ Red circles: we have completed an initial analysis ƒ Green circles: these are in progress ƒ Purple: next ƒ Red squares: Ron Reese completed sites Springs and Surface-Water Inventory

ƒ Using ArcMap and Microsoft Office Access Database

By: Leel Knowles, Jr. Joanne Dixon Aquifer-Wide Potentiometric Map

ƒ Important input to model and Birmingham Atlanta SOUTH GEORGIA CAROLINA the hydrogeologic framework I ALABAMA Macon

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G Orlando C EXPLANATION U E A ƒ Headed up by Sandy L Tam pa Water Management Districts F N

NWFWMD O Kinnaman, USGS Orlando SFWMD F

SJRWMD M SRWMD E X SWFWMD ƒ Approximately 1,900 water- I Miami C

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level measurements from 0 100 200 Miles May 11 – June 8, 2010 0 100 200 Kilometers Well Locations Used for Potentiometric Mapping Effort

90°0' 88°0' 86°0' 84°0' 82°0' 80°0' ƒ 1,900 water- SOUTH GEORGIA CAROLINA I ALABAMA

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GSA (1) ƒ Has not been O NWFWMD (174) SFWMD (63) F

done since SRWMD (233) M USGS (1276) E

TAMPA BAY WATER (40) XI 26°0' ALACHUA COUNTY (79) 1985!!! C O

0 100 200 Miles

0 100 200 Kilometers Water Use Data Compilation: Domestic, Municipal, Agricultural

Improved water-use ƒ South Carolina data for model input Georgia Alabama ƒ Mid 1970s to 2010 ƒ Monthly values Requires ƒ Florida disaggregation ƒ Linkage to well data Water Use

Data Requests NWFWMD

for Florida SRWMD

SJRWMD ƒ NWFWMD (received, thank you!) SWFWMD ƒ SRWMD (received, thank you!) ƒ SJRWMD (received, thank you!) SFWMD ƒ SWFWMD (received, thank you!) ƒ SFWMD (received, thank you!) Water-Use Data Compilation

ƒ Various sources used ƒ USGS Aggregated Water-Use Database (AWUDS) ƒ Contains aggregated quantities for various uses ƒ 1985-2005 ƒ Site-Specific Water-Use Data ƒ Florida DEP ƒ Georgia Municipal and Industrial Permitting Program ƒ Georgia Water-Use Database (USGS site-specific) ƒ South Carolina Capacity Use Area Permitting ƒ NWFWMD, SRWMD, SJRWMD, SWFWMD, SFWMD ƒ Agricultural Water-Use Estimates ƒ NESPAL (Tifton, UGA, Georgia) Water-Use Data Compilation (cont.)

ƒ Master Database ƒ Monthly values ƒ Site-specific ƒ Disaggregated data ƒ Estimated values ƒ Permit record represents a single utility or water supplier ƒ A permit has one or more sources (wells) Model Development

ƒ Started with RASA Model ƒ Preliminary Model Development Bush and Johnson RASA datasets

Precipitation Leakance Transmissivity Numerical Model Applications ƒ Water budgets over time ƒ Climate change ƒ Tool to guide data collection ƒ Saltwater Encroachment ƒ Hydrologic system response to stresses (drought, increased pumping etc.) Spatial & Temporal Variability in Water Budgets

ƒ Looking at boundaries of major groundwater basins for model ƒ 8 water budget areas used in the RASA

1980 Estimated discharge from major groundwater basins, Bush & Johnson, 1988 Salt-Water Interface (SWI) package for Numerical Model ƒ Funded by Office of Groundwater ƒ Being brought into the USGS as “official” MODFLOW-2005 package (updated with additional “bells and whistles”) ƒ Joe Hughes (USGS) heading it up ƒ Working with Mark Bakker (Delft Technology), Frans Schaars (Artesia), ƒ Chris Langevin and Alyssa Dausman (USGS) ƒ Can be used to evaluate: ƒ Sea Level Rise ƒ Seawater Encroachment (vertically and horizontally) ƒ Used in calibration of Saline Map Planned Publications and Tools

ƒ Hydrogeologic Framework (SIR) ƒ Model + Documentation (SIR) ƒ Techniques and Methods paper for SWI package ƒ Data/GIS releases (Data Series-online only, etc.) ƒ GW Availability of the Floridan aquifer (PP) ƒ Fact sheet summarizing PP Summary ƒ Framework being constructed to bring more internal consistency between districts ƒ Should have fairly comprehensive regional datasets that can be utilized locally or sub- regionally ƒ Develop and share tools to better simulate the Burke Co. GA groundwater flow system Photo: A.M. Cressler