AGRICULTURAL PESTICIDES IN SIX DRAINAGE BASINS USED FOR PUBLIC WATER SUPPLY IN NEW JERSEY, 1990 By Tamara Ivahnenko and Debra E. Buxton U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 93-4101 Prepared in cooperation with the NEW JERSEY DEPARTMENT OF ENVIRONMENTAL PROTECTION AND ENERGY West Trenton, New Jersey 1994 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Gordon P. Eaton, Director For additional information Copies of this report can be write to: purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Earth Science Information Center Mountain View Office Park Open-File Reports Section 810 Bear Tavern Road Box 25286, MS 517 Suite 206 Denver Federal Center West Trenton, NJ 08628 Denver, CO 80225 CONTENTS Page Abstract............................................................. 1 Introduction......................................................... 1 Purpose and scope............................................... 2 Description of the study area................................... 2 Physiography and geology................................... 2 Land use................................................... 3 Results of pesticide-application surveys ........................ 3 Related investigations.......................................... 7 Acknowledgments................................................. 7 Study methods........................................................ 8 Calculation of pesticide-application rate....................... 8 Selection of study basins....................................... 11 Collection of surface-water samples............................. 11 Chemical analysis of surface-water samples...................... 19 Quality-assurance/quality-control procedures.................... 20 Sample collection.......................................... 20 Chemical analysis.......................................... 20 Results of quality-assurance/quality-control procedures.... 22 Collection of pretreated- and treated-water samples............. 22 Description of study basins.......................................... 22 Lower Mine Hill Reservoir....................................... 27 South Branch of the Raritan River............................... 27 Main Branch of the Raritan River................................ 28 Millstone River................................................. 29 Manasquan River................................................. 29 Matchaponix Brook............................................... 30 Agricultural pesticides in drainage basins........................... 30 Pesticide in base flow and stormflow............................ 30 Lower Mine Hill Reservoir.................................. 31 South Branch of the Raritan River.......................... 31 Main Branch of the Raritan River........................... 37 Millstone River............................................ 37 Manasquan River............................................ 43 Matchaponix Brook.......................................... 43 Statistical analysis of pesticide concentrations in base flow and stormflow................................................. 48 Pesticides in pretreated and treated public-supply water samples 51 Summary and conclusions.............................................. 54 References cited..................................................... 55 ILLUSTRATIONS Figure 1. Map showing forty-five surface-water supply basins, six selected intakes and their associated drainage basins, and agricultural land use in New Jersey................. 4 iii ILLUSTRATIONS - -Continued Page Figure 2-6. Maps showing: 2. County boundaries and the four physiographic provinces in New Jersey .................................... 6 3. Locations of public-supply water-treatment-plant in­ takes and associated drainage basins in New Jersey 10 4. Calculated pesticide-application rates for alachlor in drainage basins used for public supply, 1985... 16 5. Calculated pesticide-application rates for atrazine in drainage basins used for public supply, 1985... 17 6. Calculated pesticide-application rates for metolachlor in drainage basins used for public supply, 1985... 18 7. Streamflow hydrograph of Yards Creek near Blairstown for the period June 8, 1990, through September 9, 1990, used to represent discharge of Lower Mine Hill Brook... 32 8. Graph showing concentrations of pesticides in three water samples collected above Lower Mine Hill Reservoir, June-August 1990....................................... 33 9. Graph showing concentrations of pesticides in three water samples collected below Lower Mine Hill Reservoir, June-August 1990....................................... 34 10. Streamflow hydrograph of the South Branch of the Raritan River at Stanton Station for the period June 9, 1990, through August 30, 1990................................ 35 11. Graph showing concentrations of pesticides in three water samples collected on the South Branch of the Raritan River near Flemington, June-August 1990................ 36 12. Streamflow hydrograph of the Raritan River at Manville for the period June 7, 1990. through August 30, 1990.. 39 13. Graph showing concentrations of pesticides in three water samples collected on the Main Branch of the Raritan River at Raritan, June-August 1990..................... 40 14. Streamflow hydrograph of the Millstone River at Blackwells Mills for the period June 18, 1990, through August 30, 1990........................................ 41 15. Graph showing concentrations of pesticides in four water samples collected on the Millstone River at Weston, June-August 1990 ...................................... 42 16. Streamflow hydrograph of the Manasquan River at Squankum for the period June 18, 1990, through September 10, 1990................................................... 44 17. Graph showing concentrations of pesticides in three water samples collected on the Manasquan River near Squankum, June-August 1990 ....................................... 45 18. Streamflow hydrograph of the Manalapan Brook near Spotswood for the period June 18, 1990, through August 30, 1990, used to represent discharge of Matchaponix Brook...................................... 46 19. Graph showing concentrations of pesticides in three water samples collected on Matchaponix Brook near Englishtown, June-August 1990....................................... 47 IV ILLUSTRATIONS - -Continued Page Figure 20. Histograms showing concentrations of atrazine and metolachlor in water samples collected at seven sampling sites......................................... 50 21. Plot showing relation between ranked concentration of metolachlor in water samples and ranked flow rate...... 52 TABLES Table 1. Geographic Information System coverages used to determine calculated pesticide-application rates and to select potential surface-water sampling basins.................. 9 2. Selected calculated pesticide-application rates in drainage basins above public surface-water-supply intakes, 1985 ............................................ 12 3. Selected calculated pesticide-application rates in drainage basins above public surface-water-supply intakes, 1988 ............................................ 14 4. Pesticides determined in water-quality samples by means of gas chromatography/chemical ionization mass spectrometry and immunoassay methods and reporting levels, June- September 1990.......................................... 21 5. Physical properties and concentrations of pesticides detected in surface-water samples collected from the six study basins, June-September 1990........................ 23 6. Maximum and minimum concentrations of pesticides detected in water-quality samples collected from the six study basins, 1990............................................ 25 7. Relative percent difference in pesticide concentrations in sequentially collected water-quality samples collected from the Lower Mine Hill Reservoir, Millstone River, and Matchaponix Brook, 1990 ................................. 26 8. Calculated pesticide-application rates in drainage basins above selected public surface-water-supply intakes, 1988 38 9. Mean, median, and standard deviations of concentrations of pesticides detected in water-quality samples, June- September 1990........................................... 49 10. Physical properties and concentrations of pesticides detected in water samples collected from water-treatment facilities, September 1990............................... 53 v CONVERSION FACTORS AND VERTICAL DATUM Multiply By. To Obtain Length inch (in.) 2.54 centimeter inch (in.) 25.40 millimeter foot (ft) 0.3048 meter mile (mi) 1.609 kilometer Area acre 0.4047 hectare square foot (ft 2 ) 0.09294 square meter square mile (mi 2 ) 2.590 square kilometer Volume gallon (gal) 3.785 liter Flow cubic feet per second 0.0283 cubic meter per second (ft s /s) million gallons per day 0.0438 cubic meter per second (Mgal/d) ass pound, avoirdupois (Ib) 0.4536 kilogram pound, avoirdupois (Ib) 0.4536 x 10 6 microgram Temperature degrees Fahrenheit (°F) «C - 5/9 (°F-32) degrees Celsius (°C) Other pound (avoirdupois) per 1,121 kilogram per hectare acre (Ib/acre) Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929--a geodetic datum derived from a general adjustment of the first-order level nets of the United States and Canada, formerly called Sea Level Datum of 1929, VI AGRICULTURAL PESTICIDES IN SIX DRAINAGE BASINS USED FOR PUBLIC WATER SUPPLY IN NEW JERSEY, 1990 By Tamara