Groundwater Quality Beneath an Area of Urban Residential and Commercial Land Use, Mobile,
Alabama 20112012 Alabama Water Resources Conference
September 6, 2012, Perdido Beach Resort, Orange Beach, AlabamaRichard Moreland, USGS, Montgomery, Alabama
National Water Quality Assessment (NAWQA) What is the condition of
Nations streams, rivers, and groundwater?
How are these changing over time?
How do Natural and human activities affect these conditions, and where are they most pronounced.
Mobile Urban Land Use Study
31 wells installed in 2010 Installed with Geoprobe direct push
machine. Two inch diameter, depths ranging from
14 to 69 feet below land surface.
29 wells sampled in 2011 – full suite of QW constituents (Nutrients, major ions, trace metals, pesticides, VOCs, DOC). Two wells were dry. Wells were developed with inertial surge pump. Purged of at least three casing volumes and
pumped until field readings of Temperature, Specific Conductance, pH, Dissolved Oxygen, and Turbidity were stable.
Mobile Urban Land Use Study
Mobile Urban Land Use Study
Residential and Light Commercial land use areas in the Mobile metropolitan area. Eliminate effects of
industrial areas and transportation corridors
Post 1970’s construction. Synthesis of 2001 MRLC
data with mid 2000’s aerial photography.
Mobile Urban Land Use Study
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Alluvial, coastal, and low terrace deposits
Citronelle Formation
High terrace deposits
Miocene Series undifferentiated
Geology
Mobile Urban Land Use Study
Quality Control Samples
Detections for nickel, manganese, styrene at levels below environmental samples.
Detections for ammonia and nitrite below environmental sample levels. Only one ammonia and two nitrite detections in environmental samples.
**Dissolved Organic Carbon had two detections in blanks, one of which was greater than any environmental sample.**
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olach
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eton
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yr0
10
20
30
40
50
60
70Pe
rcen
t of
Sam
ples Pesticides
144 analytes 22 analytes
detected
Mobile Urban Land Use Study
0.001
0.01
0.1
1
10
Conc
entr
ation
in
Mic
rogr
ams
per L
iter
Pesticides
Mobile Urban Land Use Study
MCL(3.0)
RSD(0.002)
Mobile Urban Land Use Study
Trichlo
rom
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Styre
ne
Brom
odichlo
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Carbon d
isulfi
de
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Perc
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1 1 1 1
VOC’s9 detections for 88 compounds analyzed
0.01
0.1
1
10
Conc
entr
ation
in
Mic
rogr
ams
per L
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Mobile Urban Land Use Study
MCL100
VOC concentrations
Mobile Urban Land Use Study
Summary 29 wells sampled in urban/commercial areas of
Mobile, Alabama. Field parameters consistent with recently recharged
groundwater. Nutrients similar to earlier study in Montgomery,
Alabama. 22 Pesticides detected. 9 VOC’s detected.
Montgomery Urban Land Use Study
Full network being resampled this water year.
Six sites have been sampled biannually since 2000.
Occurrence of Pesticides in GW in Areas of Intense Row Crop Production
Purpose and Scope Multi-year study – initial sampling in FY09 Evaluate trends in detection frequencies and
concentrations of pesticides in GW near areas of high-intensity row crop production.
Sample 15 wells in three areas of state.
• Northern Alabama
• Southeast Alabama
• Baldwin County Samples analyzed for temperature, specific
conductance, DO, pH, and pesticides.
Questions??
Annual Data Reports http://wdr.water.usgs.gov/
Alabama WSC Web Addresshttp://al.water.usgs.gov
Richard MorelandUSGS Alabama Water Science Center