Groundwater Quality Beneath an Area of Urban Residential and Commercial Land Use, Mobile, Alabama Alabama Water Resources Conference September 6, 2012, Perdido Beach Resort, Orange Beach, Alabama Richard Moreland, USGS, Montgomery, Alabama

 Study background  Study design  Methods  Results Mobile Urban Land Use Study

 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

 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 Residential and light commercial land use areas

Mobile Urban Land Use Study 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.**

Mobile Urban Land Use Study Field Parameters

Major Ions Piper Diagram Mobile Urban Land Use Study

Selected Major Ions Concentrations Mobile Urban Land Use Study MCL

Mobile Urban Land Use Study Select Nutrients Milligrams per Liter

Mobile Urban Land Use Study Dissolved Organic Carbon

Mobile Urban Land Use Study Select Metals Micrograms per liter

Pesticides  144 analytes  22 analytes detected Mobile Urban Land Use Study

Pesticides Mobile Urban Land Use Study MCL (3.0) RSD (0.002)

Mobile Urban Land Use Study VOC’s 9 detections for 88 compounds analyzed

Mobile Urban Land Use Study MCL 100 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 Alabama WSC Web Address Richard Moreland USGS Alabama Water Science Center