, Volume 122, Issue 2–3, pp 343–360 | Cite as

Unravelling the origin and fate of nitrate in an agricultural–urban coastal aquifer

  • Wei Wen Wong
  • Michael R. Grace
  • Ian Cartwright
  • Perran L. M. Cook


Nitrate (NO3 ) contamination in groundwater is a worldwide phenomenon and a pervasive environmental problem, particularly when NO3 -enriched groundwater discharges into a nitrogen-limited estuarine environment through submarine groundwater discharge (SGD). SGD is often associated with eutrophication which ultimately alters the coastal ecology of the receiving surface water. Identifying the sources and transformation processes of NO3 in and within the groundwater discharged to the estuary provides baseline information underpinning effective management of the coastal environments. The aims of this study were to: (1) understand the linkages between aquifers at different depths and in different parts of a catchment in the south east of Australia which underlies a eutrophic estuary (the Werribee River estuary); (2) identify and apportion the NO3 source(s) to the aquifers; and (3) identify the major transformation processes of NO3 in the aquifer along the groundwater flowpath. The average δ15N–NO3 values of the deep groundwater (+21 ‰) at the SGD hotspot lies between the enriched δ15N–NO3 (~+33 ‰) at the western side of the estuary and relatively depleted δ15N–NO3 (~+14 ‰) at the eastern side; indicating that the aquifers from both sides of the estuary are connected at the SGD hotspot. The isotopic composition of NO3 , together with the concentrations of excess nitrogen (N2) gas also revealed that SGD-derived NO3 originated predominantly from agricultural activity. Denitrification was not the primary NO3 removal process in the oxic groundwater. Instead, mixing between sewage (69 %) and fertiliser-derived (31 %) NO3 appeared to be the main control over the observed NO3 concentrations (~1,000 µmol L−1) and the relatively enriched δ15N–NO3 values (+20 to +23 ‰) in the deeper sand and gravel aquifer at the groundwater discharge zone. These results suggest that groundwater is a critical source of NO3 to the receiving surface water and as such should always be included not only in the regional but also the global N budget. The outcome of the study is a key to sustainable management of coastal aquatic ecosystems.


Groundwater Nitrate isotopes Excess nitrogen Nitrate sources Denitrification 



We thank Mardiana Ali and Poh Seng Chee for their help in the field. We thank the anonymous reviewers for their thoughtful and constructive review of the manuscript. This work was supported by Melbourne Water Corporation, the Department of Sustainability and Environment, EPA Victoria and an Australian Research Council Grant (LP110100040) to PLMC.


  1. APHA (2005) Standard methods for the examination of water and wastewater. American Public Health Association, American Water Works Association, and Water Environment Federation, WashingtonGoogle Scholar
  2. Aravena R, Robertson WD (1998) Use of multiple isotope tracers to evaluate denitrification in ground water: study of nitrate from a large-flux septic system plume. Ground Water 36(6):975–982. doi: 10.1111/j.1745-6584.1998.tb02104.x CrossRefGoogle Scholar
  3. Böhlke JK (2002) Groundwater recharge and agricultural contamination. Hydrogeol J 10(1):153–179. doi: 10.1007/s10040-001-0183-3 CrossRefGoogle Scholar
  4. Böhlke JK, Denver JM (1995) Combined use of groundwater dating, chemical, and isotopic analyses to resolve the history and fate of nitrate contamination in two agricultural watersheds, Atlantic coastal plain, Maryland. Water Resour Res 31(9):2319–2339. doi: 10.1029/95WR01584 CrossRefGoogle Scholar
  5. Böhlke JK, Smith RL, Miller DN (2006) Ammonium transport and reaction in contaminated groundwater: application of isotope tracers and isotope fractionation studies. Water Resour Res.2006;42(5). doi: 10.1029/2005WR004349
  6. Böhlke JK, Antweiler RC, Harvey JW, Laursen AE, Smith LK, Smith RL, Voytek MA (2009) Multi-scale measurements and modeling of denitrification in streams with varying flow and nitrate concentration in the upper Mississippi River basin, USA. Biogeochemistry 93:117–141. doi: 10.1007/s10533-008-9282-8 CrossRefGoogle Scholar
  7. Böttcher J, Strebel O, Voerkelius S, Schmidt HL (1990) Using isotope fractionation of nitrate-nitrogen and nitrate-oxygen for evaluation of microbial denitrification in a sandy aquifer. J Hydrol 114(3–4):413–424. doi: 10.1016/0022-1694(90)90068-9 CrossRefGoogle Scholar
  8. Böttcher J, Weymann D, Well R, Von Der Heide C, Schwen A, Flessa H, Duijnisveld WHM (2011) Emission of groundwater-derived nitrous oxide into the atmosphere: model simulations based on a 15N field experiment. Eur J Soil Sci 62(2):216–225. doi: 10.1111/j.1365-2389.2010.01311.x CrossRefGoogle Scholar
  9. Burnett WC, Dulaiova H (2003) Estimating the dynamics of groundwater input into the coastal zone via continuous radon-222 measurements. J Environ Radioact 69(1–2):21–35. doi: 10.1016/S0265-931X(03)00084-5 CrossRefGoogle Scholar
  10. Burnett WC, Warrayakorn G, Taniguchi M, Dulaiova H, Sojisuporn P, Rungsupa S, Ishitobi T (2007) Groundwater-derived nutrient inputs to the Upper Gulf of Thailand. Cont Shelf Res 27:176–190. doi: 10.1016/j.csr.2006.09.006 CrossRefGoogle Scholar
  11. Buss SR, Herbert AW, Morgan P, Thornton SF, Smith JWN (2004) A review of ammonium attenuation in soil and groundwater. Q J Eng GeolHydrogeol 37(4):347–359. doi: 10.1144/1470-9236/04-005 CrossRefGoogle Scholar
  12. Butler NB (1982) Carbon dioxide equilibria and their applications. Addison-Wesley Publishing Co., Inc, New YorkGoogle Scholar
  13. Casciotti KL, Sigman DM, Hastings MG, Böhlke JK, Hilkert A (2002) Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method. Anal Chem 74(19):4905–4912. doi: 10.1021/ac020113w CrossRefGoogle Scholar
  14. Choi BY, Yun ST, Mayer B, Kim KH (2011) Sources and biogeochemical behavior of nitrate and sulfate in an alluvial aquifer: hydrochemical and stable isotope approaches. Appl Geochem 26(7):1249–1260. doi: 10.1016/j.apgeochem.2011.04.015 CrossRefGoogle Scholar
  15. Clark ID, Fritz P (1997) Environmental isotopes in hydrogeology. Lewis, New YorkGoogle Scholar
  16. Dahlhaus PG, Heislers DS, Brewin D, Leonard JL, Dyson PR, Cherry D. Port Phillip and Westernport groundwater flow systems, Port Phillip and Westernport catchment management authority. (2004). Accessed 30 Apr 2013
  17. Deurer M, von der Heide C, Böttcher J, Duijnisveld WHM, Weymann D, Well R (2008) The dynamics of N2O near the groundwater table and the transfer of N2O into the unsaturated zone: a case study from a sandy aquifer in Germany. Catena 72(3):362–373. doi: 10.1016/j.catena.2007.07.013 CrossRefGoogle Scholar
  18. Deutsch B, Mewes M, Liskow I, Voss M (2006) Quantification of diffuse nitrate inputs into a small river system using stable isotopes of oxygen and nitrogen in nitrate. Org Geochem 37(10):1333–1342. doi: 10.1016/j.orggeochem.2006.04.012 CrossRefGoogle Scholar
  19. D’Haene K, Moreels E, De Neve S, Daguilar BC, Boeckx P, Hofman G, Van Cleemput O (2003) Soil properties influencing the denitrification potential of Flemish agricultural soils. Biol Fertil Soils 38(6):358–366. doi: 10.1007/s00374-003-0662-x CrossRefGoogle Scholar
  20. Fry B (1991) Stable isotope diagrams of freshwater food webs. Ecology 72(6):2293–2297. doi: 10.2307/1941580 CrossRefGoogle Scholar
  21. Fukada T, Hiscock KM, Dennis PF, Grischek T (2003) A dual isotope approach to identify denitrification in groundwater at a river-bank infiltration site. Water Res 37(13):3070–3078. doi: 10.1016/S0043-1354(03)00176-3 CrossRefGoogle Scholar
  22. Groffman PM, Boulware NJ, Zipperer WC, Pouvat RV, Band LE, Colosimo MF (2002) Soil nitrogen cycle processes in urban riparian zones. Environ Sci Technol 36:4547–4552. doi: 10.1021/es020649z CrossRefGoogle Scholar
  23. Gruber N, Galloway JN (2008) An Earth-system perspective of the global nitrogen cycle. Nature 451:293–296. doi: 10.1038/nature06592 CrossRefGoogle Scholar
  24. Holden PA, Fierer N (2005) Microbial processes in the vadose zone. Vadose Zone J 4(1):1–21CrossRefGoogle Scholar
  25. Holdgate GR, Gallagher SJ, Wallace MW (2002) Tertiary coal geology and stratigraphy of the Port Phillip Basin, Victoria. Aust J Earth Sci 49(3):437–453. doi: 10.1046/j.1440-0952.2002.00930.x CrossRefGoogle Scholar
  26. Holocher J, Peeters F, Aeschbach-Hertig W, Hofer M, Brennwald M, Kinzelbach W, Kipfer R (2002) Experimental investigations on the formation of excess air in quasi-saturated porous media. Geochim Cosmochim Acta 66(23):4103–4117. doi: 10.1016/S0016-7037(02)00992-4 CrossRefGoogle Scholar
  27. Hook AM, Yeakley JA (2005) Stormflow dynamics of dissolved organic carbon and total dissolved nitrogen in a small urban watershed. Biogeochemistry 75:409–431. doi: 10.1007/s10533-005-1860-4 CrossRefGoogle Scholar
  28. Johannes RE, Hearn CJ (1985) The effect of submarine groundwater discharge on nutrient and salinity regimes in a coastal lagoon off Perth, Western Australia. Estuar Coast Shelf Sci 21:789–800. doi: 10.1016/0272-7714(85)90073-3 CrossRefGoogle Scholar
  29. Katz BG, Griffin DW, McMahon PB, Harden HS, Wade E, Hicks RW, Chanton JP (2010) Fate of effluent-borne contaminants beneath septic tank drainfields overlying a karst aquifer. J Environ Qual 39(4):1181–1195. doi: 10.2134/jeq2009.0244 CrossRefGoogle Scholar
  30. Kaushal SS, Groffman PM, Band LE, Elliott EM, Shields CA, Kendall C (2011) Tracking nonpoint source nitrogen pollution in human-impacted watersheds. Environ Sci Technol 45:8225–8232. doi: 10.1021/es200779e CrossRefGoogle Scholar
  31. Kendall C, Elliott EM, Wankel SD (2007) Tracing anthropogenic inputs of nitrogen to ecosystems. In: Michener RH, Lajtha K (eds) Stable isotopes in ecology and environmental science, 2nd edn. Blackwell Publishing Ltd, Boston, pp 375–449CrossRefGoogle Scholar
  32. Kroeger KD, Charette MA (2008) Nitrogen biogeochemistry of submarine groundwater discharge. Limnol Oceanogr 53(3):1025–1039CrossRefGoogle Scholar
  33. LaMontagne MG, Duran R, Valiela I (2003) Nitrous oxide sources and sinks in coastal aquifers and coupled estuarine receiving waters. Sci Total Environ 309(1–3):139–149. doi: 10.1016/S0048-9697(02)00614-9 CrossRefGoogle Scholar
  34. Laroche J, Nuzzi R, Waters R, Wyman K, Falkowski P, Wallace D (1997) Brown tide blooms in long Island’s coastal waters linked to interannual variability in groundwater flow. Glob Change Biol 3:397–410. doi: 10.1046/j.1365-2486.1997.00117.x CrossRefGoogle Scholar
  35. Mayer B, Bollwerk SM, Mansfeldt T, Hütter B, Veizer J (2001) The oxygen isotope composition of nitrate generated by nitrification in acid forest floors. Geochim Cosmochim Acta 65(16):2743–2756. doi: 10.1016/S0016-7037(01)00612-3 CrossRefGoogle Scholar
  36. Mayer B, Boyer EW, Goodale C, Jaworski NA, Van Breemen N, Howarth RW, Seitzinger S, Billen G, Lajtha K, Nadelhoffer K, Van Dam D, Hetling LJ, Nosal M, Paustian K (2002) Sources of nitrate in rivers draining sixteen watersheds in the northeastern U.S.: isotopic constraints. Biogeochemistry 57–58:171–197. doi: 10.1023/A:1015744002496 CrossRefGoogle Scholar
  37. McMahon PB, Böhlke JK (1996) Denitrification and mixing in a stream–aquifer system: effects on nitrate loading to surface water. J Hydrol 186(1–4):105–128. doi: 10.1016/S0022-1694(96)03037-5 CrossRefGoogle Scholar
  38. Mitsch WJ, Day JW, Gilliam JW, Groffman PM (2001) Reducing nitrogen loading to the Gulf of Mexico from the Mississippi River Basin: strategies to counter a persistent ecological problem. Bioscience 51:373–388CrossRefGoogle Scholar
  39. Osaka KI, Ohte N, Koba K, Yoshimizu C, Katsuyama M, Tani M, Tayasu I, Nagata T. Hydrological influences on spatiotemporal variations of δ15N and δ18O of nitrate in a forested headwater catchment in central Japan: denitrification plays a critical role in groundwater. J Geophys Res Biogeosci. 2010;115(G2). doi: 10.1029/2009jg000977
  40. Panno SV, Hackley KC, Hwang HH, Greenberg SE, Krapac IG, Landsberger S, O’Kelly DJ (2006) Characterization and identification of Na-Cl Sources in ground water. Ground Water 44(2):176–187. doi: 10.1111/j.1745-6584.2005.00127.x CrossRefGoogle Scholar
  41. Parker SR, Gammons CH, Garrett Smith M, Poulson SR (2012) Behavior of stable isotopes of dissolved oxygen, dissolved inorganic carbon and nitrate in groundwater at a former wood treatment facility containing hydrocarbon contamination. Appl Geochem 27(6):1101–1110. doi: 10.1016/j.apgeochem.2012.02.035 CrossRefGoogle Scholar
  42. Peterson RN, Santos IR, Burnett WC (2010) Evaluating groundwater discharge to tidal rivers based on a Rn-222 time-series approach. Estuar Coast Shelf Sci 86(2):165–178. doi: 10.1016/j.ecss.2009.10.022 CrossRefGoogle Scholar
  43. Rivett MO, Buss SR, Morgan P, Smith JWN, Bemment CD (2008) Nitrate attenuation in groundwater: a review of biogeochemical controlling processes. Water Res 42(16):4215–4232. doi: 10.1016/j.watres.2008.07.020 CrossRefGoogle Scholar
  44. Rutkowski CM, Burnett WC, Iverson RL, Chanton JP (2011) The effect of groundwater seepage on nutrient delivery and seagrass distribution in the northeastern Gulf of Mexico. Estuaries 22(4):1033–1040. doi: 10.2307/1353081
  45. Santos IR, Burnett WC, Chanton J, Mwashote B, Suryaputra IGNA, Dittmar T (2008) Nutrient biogeochemistry in a Gulf of Mexico subterranean estuary and groundwater-derived fluxes to the coastal ocean. Limnol Oceanogr 53:705–718CrossRefGoogle Scholar
  46. Sebilo M, Mayer B, Grably M, Billion D, Mariotti A (2004) The use of the ‘ammonium diffusion’ method for δ15N-NH4 + and δ15N–NO3 measurements: comparison with other techniques. Environ Chem 1(2):99–103. doi: 10.1071/EN04037 CrossRefGoogle Scholar
  47. Sigman DM, Casciotti KL, Andreani M, Barford C, Galanter M, Böhlke JK (2001) A bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater. Anal Chem 73(17):4145–4153. doi: 10.1021/ac010088e CrossRefGoogle Scholar
  48. Singleton MJ, Esser BK, Moran JE, Hudson GB, McNab WW, Harter T (2007) Saturated zone denitrification: potential for natural attenuation of nitrate contamination in shallow groundwater under dairy operations. Environ Sci Technol 41(3):759–765. doi: 10.1021/es061253g CrossRefGoogle Scholar
  49. Slomp CP, Van Cappellen P (2004) Nutrient inputs to the coastal ocean through submarine groundwater discharge: controls and potential impact. J Hydrol 295(1–4):64–86. doi: 10.1016/j.jhydrol.2004.02.018 CrossRefGoogle Scholar
  50. Smith EL, Kellman LM (2011) Nitrate loading and isotopic signatures in subsurface agricultural drainage systems. J Environ Qual 40(4):1257–1265. doi: 10.2134/jeq2010.0489 CrossRefGoogle Scholar
  51. Spalding RF, Exner ME (1993) Occurrence of nitrate in groundwater—a review. J Environ Qual 22(3):392–402CrossRefGoogle Scholar
  52. Spiteri C, Slomp CP, Charette MA, Tuncay K, Meile C (2008) Flow and nutrient dynamics in a subterranean estuary (Waquoit Bay, MA, USA): field data and reactive transport modeling. Geochim Cosmochim Acta 72(14):3398–3412. doi: 10.1016/j.gca.2008.04.027 CrossRefGoogle Scholar
  53. Starr RC, Gillham RW (1993) Denitrification and organic carbon availability in two aquifers. Ground Water 31(6):934–947CrossRefGoogle Scholar
  54. Su N, Burnett W, Macintyre H, Liefer J, Peterson R, Viso R (2014) Natural radon and radium isotopes for assessing groundwater discharge into little lagoon, AL: implications for harmful algal blooms. Estuar Coasts 37:893–910. doi: 10.1007/s12237-013-9734-9 CrossRefGoogle Scholar
  55. Tesoriero AJ, Liebscher H, Cox SE (2000) Mechanism and rate of denitrification in an agricultural watershed: electron and mass balance along groundwater flow paths. Water Resour Res 36:1545–1559. doi: 10.1029/2000wr900035 CrossRefGoogle Scholar
  56. Umezawa Y, Hosono T, Onodera SI, Siringan F, Buapeng S, Delinom R, Yoshimizu C, Tayasu I, Nagata T, Taniguchi M (2008) Sources of nitrate and ammonium contamination in groundwater under developing Asian megacities. Sci Total Environ 404(2–3):361–376. doi: 10.1016/j.scitotenv.2008.04.021 CrossRefGoogle Scholar
  57. Valiela I, Costa J, Foreman K, Teal JM, Howes B, Aubrey D (1990) Transport of groundwater-borne nutrients from watersheds and their effects on coastal waters. Biogeochemistry 10(3):177–197. doi: 10.1007/BF00003143 CrossRefGoogle Scholar
  58. van Breukelen BM, Griffioen J, Röling WFM, van Verseveld HW (2004) Reactive transport modelling of biogeochemical processes and carbon isotope geochemistry inside a landfill leachate plume. J Contam Hydrol 70(3–4):249–269. doi: 10.1016/j.jconhyd.2003.09.003 CrossRefGoogle Scholar
  59. Vogel JC, Talma AS, Heaton THE (1981) Gaseous nitrogen as evidence for denitrification in groundwater. J Hydrol 50(C):191–200CrossRefGoogle Scholar
  60. Weiss RF (1970) The solubility of nitrogen, oxygen and argon in water and seawater. Deep Sea Res Oceanogr Abstr 17(4):721–735. doi: 10.1016/0011-7471(70)90037-9 CrossRefGoogle Scholar
  61. Weiss RF, Price BA (1980) Nitrous oxide solubility in water and seawater. Mar Chem 8(4):347–359CrossRefGoogle Scholar
  62. Weymann D, Well R, Flessa H, Von Der Heide C, Deurer M, Meyer K, Konrad C, Walther W (2008) Groundwater N2O emission factors of nitrate-contaminated aquifers as derived from denitrification progress and N2O accumulation. Biogeosciences 5(5):1215–1226CrossRefGoogle Scholar
  63. Wong WW, Grace MR, Cartwright I, Cardenas MB, Zamora PB, Cook PLM (2013) Dynamics of groundwater-derived nitrate and nitrous oxide in a tidal estuary from radon mass balance modeling. Limnol Oceanogr 58:1689–1706. doi: 10.4319/lo.2013.58.5.1689 CrossRefGoogle Scholar
  64. Wong WW, Grace MR, Cartwright I, Cook PLM (2014) Sources and fate of nitrate in a groundwater-fed estuary elucidated using stable isotope ratios of nitrogen and oxygen. Limnol Oceanogr 59(5):1493–1509. doi: 10.4319/lo.2014.59.5.1493 CrossRefGoogle Scholar
  65. Xue D, Botte J, De Baets B, Accoe F, Nestler A, Taylor P, Van Cleemput O, Berglund M, Boeckx P (2009) Present limitations and future prospects of stable isotope methods for nitrate source identification in surface and groundwater. Water Res 43(5):1159–1170. doi: 10.1016/j.watres.2008.12.048 CrossRefGoogle Scholar

Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  • Wei Wen Wong
    • 1
  • Michael R. Grace
    • 1
  • Ian Cartwright
    • 2
  • Perran L. M. Cook
    • 1
  1. 1.Water Studies Centre, School of ChemistryMonash UniversityClaytonAustralia
  2. 2.School of Earth, Atmosphere and EnvironmentMonash UniversityClaytonAustralia

Personalised recommendations