October 13, 2005

NAWQA AG/URBAN REPORT OUTLINE

I. INTRODUCTION

A. Background

B. Purpose and Scope

i.  Characterize shallow groundwater for region (7 study units)

ii. Examine occurrences of contaminants in urban and agricultural settings

iii. Evaluate differences in detection frequencies and, where possible,

concentrations for contaminants of concern for land-use study wells as

related to explanatory variables such as population density, influence of septic tanks, and well depth.

C. Acknowledgements

II. DESCRIPTION OF STUDY AREAS

A. CAZB

B. GRSL

C. NVBR

D. RIOG

E. SACR

F. SANJ

G. SOCA

III. PREVIOUS STUDIES

A.  Nutrients: Nolan and others 2002; Puckett and Cowdery, 2002; Nolan, 2001.

B.   Pesticides: Barbash and others 1999, 2000

C.  VOC’s: Squillace and others 1996, 1999, 2004, 2005; Ivahnenko and Barbash, 2004

D.  Study unit reports already published: Hamlin and others, 2002, 2005; Shelton, 2005; Gellenbeck and Anning, 2002; Edmonds and Gellenbeck, 2002; Lico, 1998; Rosen, 2003; Shipley and Rosen, 2005.

IV. METHODS

A.  Data Collection Methods

  i. Site selection (NAWQA Land-Use Study Protocols)

 ii. Sample collection (NAWQA GW Protocol)

iii. QA/QC

B.  Creation of Databases

             i.  QW (NAWQA Data Warehouse)

ii.  Geospatial (GIS Coverages) -- Ancillary Data (population density,

sewer/septic tank, infliltration rates, well depth/screened interval, pesticide use, crop type, DO, etc); where we obtained data/GIS coverages

C.  Data Analysis

      i.  Nutrients: Concentration analyses (Ag/Urban, among study units)

      ii. Pesticides and VOCs: methods of detection frequency analyses;

          censorship criteria (pesticides info rich; VOCs 0.2 ug/L)

iii. Geochemical analyses (redox considerations/TANC methods)

iv.  Statistical Analyses (multivariate analysis, probability analysis)

V. RESULTS

A.  Data Description (number of wells, how many analyses, number of

      constituents, sources of bias and how we handled it, number of qa/qc

      samples, summary of qa/qc)

B.  Data Limitations (representation of land use – SANJ/NVBR, changes in

      mdl’s over time, data collected for purposes other than NAWQA land use

      studies)

C.  Detection Frequency/Concentration Analyses

i. Nutrients

1. Concentration Analyses -- AG/URBAN

2. Concentration Analyses --  Among study units

ii. Pestcides – Detection frequency analyses; occurrences unique to particular study units (SACR, SANJ)

iii. Volatile Organic Compounds – Detection frequency analysis

D.  ANCILLARY DATA  (Association with detection frequency/concentration analyses)

             i.  Population Density

      ii.  Pesticide Use

     iii. Well Depth/Screened Interval

     iv. Infiltration rates

      v. Public sewer/Septic systems

     vi.  Dissolved oxygen/REDOX (General discussion only)

E.  MULTIPLE REGRESSION/PROBABILITY ANALYSES

VI. SUMMARY AND CONCLUSIONS

A.  General detection frequency and concentration analyses

B.   Ancillary data and descriptors used to predict occurrence; which predictors worked which ones didn’t

C.  Redox and pesticide/VOC detection frequencies

D.  Future research directions

VII. REFERENCES

VIII. APPENDICES

LIST OF FIGURES (continuing to modify)

1. US map showing location of study areas.

2. Map showing the major lithology within study areas

3. Individual study areas showing location of wells

4. Land-use maps

      A.  Agricultural and Urban areas within study area (show heavy, moderate, light areas)

      B.  General dominant crop types within study area

      C. General pesticide use within study area (heavy, moderate, light by class)

      D.  TCE/PCE plume locations – this looks like it will be problematic

5. Boxplots comparing constituents detection frequencies/concentrations

A.  Nutrients – nitrate, phosphorus

            i. General concentration analyses: Ag/Urban; among Study Units

            ii. Concentration analyses: public sewer vs septic systems

B.  Pesticides – triazines, ureas, carbamates, other

i.  Pesticide Class: Detection frequency analyses -- Ag/Urban

ii. Specific pesticides: Detection frequency analyses -- Ag/Urban; pesticides unique to particular study units (SACR, SANJ)

C. VOC’s – THM’s, MTBE (+ BTEX), CFC’s, fumigants, solvents

            i.  VOC Class: Detection frequency analyses – Ag/Urban

            ii.  Specific VOC’s: Detection frequency analyses; VOC’s that may be

            unique to particular study units

LIST OF TABLES (continuing to modify)

1. General SU Characteristics: gw type; precipitation, lithology, percent ag/urban in general area, primary crop types

2. Pesticides and VOCs: Classes, Uses

3. Pesticide and VOCs: mdl’s, lrl’s, censoring limits used

4. Drinking water standards

5. Summary of QA/QC data

6. Summary of exceedances of standards.