Nitrate and Groundwater Flow to Springs in the Upper Floridan aquifer, Lower ACF —Chipola Basin

by Christy Crandall U.S. Department of the Interior U.S. Geological Survey

Objectives of Study —2007 through 2009

1) To quantify • • • groundwater travel times areas contributing recharge hydrologic and geochemical processes occurring along flowpaths 2) Test 3 nitrogen management scenarios from 2002 through 2050 in areas contributing recharge to Jackson Blue, Baltzell Group, and Sandbag Springs.

• • • Cessation of nitrogen input after 2001 4 percent decline per year of nitrogen input Maintain nitrogen input at 2001 levels

Study Area

Study Area Lower ACF Basin Elevation Streams Physiographic provinves

Floridan Aquifer System Named Springs Mapped Closed-basin depressions Confinement Status

Crack-in-the-woods Spring in the Chipola River Bed

Approximately 50 % of the Land Use is Agriculture

ACFB agricultural land use study -- trend data for nitrate

Regional Model

Sub-Models And Selected Groundwater sites

Results

Water Quality Results

STATION ID 305725085094102 305219085144901 304948085140501 304746085223201 304707085153301 304718085132000 305137085060301 305025085082101 02358795 STATION NAME WELL DEPTH 115 MALONE No. 02 37 JAPSTER001 - BALTZELL SPRING GROUP CITY OF COTTONDALE NO.3, 128 70 HUTTON - SAND BAG SPRING 65 NWFWMD 80 85 NWFWMD 85 JACKSON BLUE SPRING - DO 6.6

8.5

9.5

3.0

8.0

5.4

8.5

7.0

10.

DOC <0.3

0.6

<0.2

0.6

0.4

<0.3

<0.4

<0.3

<0.3

FE <6 <6 <6 30 <6 <6 <6 <6 <6 NO 3 as N 6.43

6.39

N15/N14 3.46

3.85

3.74

0.99

0.37

0.49

3.81

3.13

7.36

7.62

7.01

2.00

3.27

3.24

2.23

2.31

AGE OF RECHARGE WATER AND PARTICLE TRACKING RESULTS

Preliminary Age Dating Results

Table __. Summary of apparent ages (averages) from Piston Flow model.

c113/c11 Hutton CFC-11 Jackson Blue Modern CFC-12 Contam.

CFC-113 Contam. Contam. Contam.

21 SF6 16 17 %young ratio Sandbag 12 Contam.

22 19 25 24 Cottondale Baltzell Baxter Hwy69-VISA JAPST001 Malone #2 32 Contam.

Contam. Contam. Contam.

25 19 23 24 Contam.

18 18 15 20 20 20 22 30 16 16 14 21 13 82 65 73 15 19 18

Particle Age and Area Contributing Recharge to Springs pART

160 140 120 100 80 60 40 20 0 40 35 30 25 20 15 10 5 0

Baltzell Spring Group

120,00% 100,00% 80,00% Frequency Cumulative % 60,00% 40,00% 20,00% 0,00%

Particle Tracking Age in Years Sandbag Spring

25 120,00% 100,00% 20 80,00% 15 10 Frequency Cumulative % 60,00% 40,00% 5 20,00% 0 7.91

15.04 22.17 29.30 36.43 43.56 More

Particle Tracking Age in Years

0,00%

Jackson Blue Spring

Frequency Cumulative % 100,00% 90,00% 80,00% 70,00% 60,00% 50,00% 40,00% 30,00% 20,00% 10,00% 0,00%

Statistic Maximum Minimum Average Median Standard Deviation Particle Tracking Age in Years Sandbag

50.69

Jackson

78.23

Baltzell

45.65

7.91

0.01

0.12

21.11

20.44

10.66

9.82

8.49

6.46

17.54

14.05

11.49

NITRATE IN THE UPPER FLORIDAN AQUIFER AND SCENARIOS

Uncertainties of Fertilizer Data Locations of use?

Nitrate Input Estimated from Fertilizer Sales Data

14,00 12,00 10,00 8,00 6,00 4,00 2,00 K 0,00 1945 1955 1965 1975 1985 1995 Jackson County, Florida, 1945 to 2001

Estimated changes in nitrate concentrations in Jackson Blue, Baltzell Group, and Sandbag Spring from 2002 through 2050 with 3 different management scenarios

• • • Cessation of nitrogen input after 2001 4 percent decline per year of nitrogen input Maintain nitrogen input at 2001 levels

Estimated changes in nitrate concentrations in Jackson Blue Spring from 2002 through 2050 with 3 different management scenarios 4,00 3,50 3,00 2,50 2,00 1,50 1,00 0,50 0,00 1945 1965

Jackson Blue Spring

1985

Year

2005 Zeroed Constant Decline NO3 Obs 2025 2045

Estimated changes in nitrate concentrations in Baltzell Spring Group from 2002 through 2050 with 3 different management scenarios

Baltzell Spring Group

7,00 6,00 5,00 4,00 3,00 2,00 1,00 0,00 1945 1965 1985

Year

2005 2025 NO3 Obs Zeroed Constant Decline 2045

Estimated changes in nitrate concentrations in Sandbag Spring from 2002 through 2050 with 3 different management scenarios 0,60 0,50 0,40 0,30 0,20 0,10 0,00 1945 1965

Sandbag Spring

1985

Year

2005 2025 Zeroed Constant Decline NO3 obs 2045

Future of Study

Future Directions--Large Objectives



Develop linked groundwater/surface water model to calculate daily stage, stream flux, and head, as a function of pumpage, rainfall, upstream conditions, climate events, and dam releases through 2050

Future Directions —my tasks



Convert Current Model to transient flow model



Use more sophisticated unsaturated flow and streamflow routing to account for aquifer stream interaction, evaporation and recharge in the surficial aquifer/residium.



Calibrate transient model for 1978 to 2008 recharge, stream and spring flow and pumpage conditions.