Environmental Science and Pollution Research

, Volume 26, Issue 3, pp 2089–2104 | Cite as

Evaluation of sources and fate of nitrates in the western Po plain groundwater (Italy) using nitrogen and boron isotopes

  • Manuela LasagnaEmail author
  • Domenico Antonio De Luca
Groundwater under threat from diffuse contaminants: improving on-site sanitation, agriculture and water supply practices


Diffuse nitrate pollution in groundwater is currently considered one of the major causes of water quality degradation. Determining the sources of nitrate contamination is an important first step for a better management of water quality. Thus, the isotopic composition of nitrate (δ15NNO3 and δ18ONO3) and boron (δ11B) were used to evaluate nitrate contamination sources and to identify geochemical processes occurring in the shallow and deep aquifers of the Turin-Cuneo plain (NW Italy). The study area is essentially an agricultural zone, where use of synthetic nitrogenous fertilizers and organic manure is a common practice and the connection to sewer services is locally lacking. Also livestock farming are highly developed. A groundwater sampling campaign was performed on 34 wells in the shallow aquifer and 8 wells in the deep aquifers, to analyze nitrate, chloride, boron, δ15NNO3, δ18ONO3 and δ11B. Isotope data of nitrate indicate that nitrate contamination in the Turin-Cuneo plain originates from mixtures of synthetic and organic sources, slightly affected by denitrification, and manure or septic tank effluents. Moreover, boron isotopes were used to discriminate further among the main anthropogenic sources of pollution. The analyses results confirm that both animal manure and domestic sewage, especially under the city of Turin, can contribute to the nitrate contamination. The isotope analysis was also used for the evaluation of denitrification and nitrification processes: contrary to expectations, a significant denitrification phenomenon was assessed only in the shallow unconfined aquifer, especially in the Poirino Plateau, the most contaminated sector of the study area.


Nitrogen stable isotopes Boron Nitrate sources Groundwater pollution NW Italy 



This study was supported financially, especially for the nitrate and boron isotopic analyses, by Fondazione Cassa di Risparmio di Torino under the project “Valutazione dell'origine della contaminazione da nitrati nelle acque sotterranee della pianura piemontese.”


  1. ADAS (2011) Economics report for NIT18 NVZ action programme impact assessment pp41.
  2. AdBPo (2001). Piano stralcio per l’Assetto Idrogeologico (PAI). D.P.C.M. 24 maggio 2001Google Scholar
  3. Agrawal GD, Lunkad SK, Malkhed T (1999) Diffuse agricultural nitrate pollution of groundwaters in India. Wat Sci Technol 39(3):67–75Google Scholar
  4. Al-Agha MR (1999) Impact of waste water management on groundwater quality in the Gaza Strip, Palestine. In: Chilton (ed) Groundwater in the urban environment: selected city profiles. Balkema, Rotterdam, pp 77–84Google Scholar
  5. APAT-IRSA (2003) Analytical methods for waters (in Italian). Serie APAT Manuali e Linee Guida 29/2003. APAT, RomeGoogle Scholar
  6. Aravena R, Robertson WD (1998) Use of multiple isotope tracers to evaluate denitrification in ground water: study of nitrate from a largeflux septic system plume. Ground Water 36(6):975–982. Google Scholar
  7. Aravena R, Evans ML, Cherry JA (1993) Stable isotopes of oxygen and nitrogen in source identification of nitrate from septic tanks. Ground Water 31(2):180–186. Google Scholar
  8. Baker L (1992) Introduction to nonpoint source pollution in the United States and prospects for wetland use. Ecol Eng 1(1-2):1–26. Google Scholar
  9. Barbero D, De Luca DA, Forno MG, Lasagna M (2016) Preliminary results on temperature distribution in the quaternary fluvial and outwash deposits of the Piedmont Po Plain (NW Italy): a statistical approach. Rend Online Soc Geol Ital 41(2016):272–275. Google Scholar
  10. Barrett MH, Howard AG (2002) Urban groundwater and sanitation—developed and developing countries. In: KWF H, Israfilov RG (eds) Current problems of hydrogeology in urban areas. Urban agglomerates and industrial centres. Kluwer Academic, Amsterdam, pp 39–56Google Scholar
  11. Bassett RL, Buszka PM, Davidson GR, Chong-Diaz D (1995) Identification of groundwater solute sources using boron isotopic composition. Environ Sci Technol 29(12):2915–2922. Google Scholar
  12. Bortolami GC, Maffeo B, Maradei V, Ricci B, Sorzana F (1976) Lineamenti di litologia e geoidrologia del settore piemontese della Pianura Padana. Quaderni dell’Istituto di Ricerca sulle Acque 28(1):3–37 RomaGoogle Scholar
  13. Bove A, Casaccio D, Destefanis E, De Luca DA, Lasagna M, Masciocco L, Ossella L, Tonussi M (2005) Idrogeologia della pianura piemontese, Regione Piemonte. Mariogros Industrie Grafiche S.p.A, Torino (CD-Rom)Google Scholar
  14. Bucci A, Barbero D, Lasagna M, Forno MG, De Luca DA (2017) Shallow groundwater temperature in the Turin area (NW Italy): vertical distribution and anthropogenic effects. Environ Earth Sci 76(5):221. Google Scholar
  15. Canavese PA, De Luca DA, Masciocco L (2004) La rete di monitoraggio delle acque sotterranee delle aree di pianura della Regione Piemonte: quadro idrogeologico. Prismas: il monitoraggio delle acque sotterranee nella Regione Piemonte. Mariogros Industrie Grafiche S.p.A., Torino, 180 ppGoogle Scholar
  16. Capri E, Civita M, Corniello A, Cusimano G, De Maio M, Ducci D, Fait G, Fiorucci A, Hauser S, Pisciotta A, Pranzini G, Trevisan M, Delgado Huertas A, Ferrari F, Frullini R, Nisi B, Offi M, Vaselli O, Vassallo M (2009) Assessment of nitrate contamination risk: the Italian experience. J Geochem Explor 102(2):71–86. Google Scholar
  17. Castagna S, Dino GA, Lasagna M, De Luca DA (2015a) Environmental issues connected to the quarry lakes and chance to reuse fine materials deriving from aggregate treatments. In: Lollino G et al (eds) Engineering geology for society and territory–volume 5, urban geology, sustainable planning and landscape exploitation. Springer International Publishing, Switzerland, pp 71–74.–3–319-09048-1_13 Google Scholar
  18. Castagna SED, De Luca DA, Lasagna M (2015b) Eutrophication of Piedmont quarry lakes (north-western Italy): hydrogeological factors, evaluation of trophic levels and management strategies. J Environ Assess Pol Manag 17:4 (21 pages), Imperial College Press. Google Scholar
  19. Choi WJ, Lee SM, Ro HM (2003) Evaluation of contamination sources of groundwater NO3 using nitrogen isotope data: a review. Geosci J 7(1):81–87. Google Scholar
  20. Chowdary VM, Rao NH, Sarma PBS (2005) Decision support framework for assessment of non-point-source pollution of groundwater in large irrigation projects. Agric Water Manag 75(3):194–225. Google Scholar
  21. Clark I, Fritz P (1997) Environmental isotopes in hydrogeology. Lewis Publishers, New York, p 328Google Scholar
  22. Clemente P, Lasagna M, Dino GA, De Luca DA (2015) Comparison of different methods for detecting irrigation canals leakage. In: Lollino G et al (eds) Engineering geology for society and territory–volume 3, River Basins, reservoir sedimentation and water resources. Springer International Publishing, Switzerland, pp 23–26.–3–319-09054-2_5 Google Scholar
  23. Comina C, Lasagna M, De Luca DA, Sambuelli L (2014) Geophysical methods to support correct water sampling locations for salt dilution gauging. Hydrol Earth Syst Sci 18(8):3195–3203. Google Scholar
  24. De Luca DA, Lasagna M, Morelli di Popolo e Ticineto A (2007) Installation of a vertical slurry wall around an Italian quarry lake: complications arising and simulation of the effects on groundwater flow. Environ Geol 53(1):177–189. Google Scholar
  25. De Luca DA, Dell’Orto V, Destefanis E, Forno MG, Lasagna M, Masciocco L (2009) Hydrogeological structure of the “fontanili” in Turin plain. Rend Online Soc Geol Ital 6:199–200Google Scholar
  26. De Luca DA, Destefanis E, Forno MG, Lasagna M, Masciocco L (2014) The genesis and the hydrogeological features of the Turin Po Plain fontanili, typical lowland springs in northern Italy. Bull Eng Geol Environ 73:409–427. Google Scholar
  27. Debernardi L., De Luca DA, Lasagna M (2005) Il processo di denitrificazione naturale nelle acque sotterranee in Piemonte “natural denitrification in groundwater in the western sector of the Po plain (northern Italy)”. Proceedings of aquifer vulnerability and risk, 2nd international workshop and 4th National Congress on the protection and Management of Groundwater-Reggia di Colorno (PR), Italy, 21–23 September 2005, paper ID 176, 27 ppGoogle Scholar
  28. Debernardi L, De Luca DA, Lasagna M (2008) Correlation between nitrate concentration in groundwater and parameter affecting aquifer intrinsic vulnerability. Environ Geol 55(3):539–558. Google Scholar
  29. DGR 23–13437 (2004) Decreto legislativo 11 maggio 1999 n. 152 art. 44. Adozione del Piano regionale di tutela delle acque (PTA) e proposta al Consiglio Regionale della relativa approvazione. Suppl. al B.U. n. 44 del 4 novembre 2004Google Scholar
  30. DGR. 28–2845 (2006). Modifiche e integrazioni alla D.G.R. 20 settembre 2004 n. 23–13437 (come modificata dalla d.g.r. 17 gennaio 2005, n. 30–14577) di adozione del Piano di tutela delle acque e proposta al Consiglio Regionale della relativa approvazione. B.U. n. 21 del 25 / 05/2006Google Scholar
  31. DPGR 12/R (2007) Designazione di ulteriori zone vulnerabili da nitrati di origine agricola ai sensi del decreto legislativo 3 aprile 2006, n. 152. (Legge regionale 29 dicembre 2000, n. 61). B.U. Regione Piemonte, numero 1–3 gennaio 2008Google Scholar
  32. DPGR 9/R (2002) Regolamento regionale recante: Designazione delle zone vulnerabili da nitrati di origine agricola e relativo programma d’azione. Bollettino Ufficiale Regione Piemonte, 2° Suppl. al numero 43–24 ottobre 2002Google Scholar
  33. European Commission (1991) Directive 91/676/EEC. Council directive of 12 December 1991 concerning the protection of waters against pollution caused by nitrates from agricultural sources. Off J Eur Communities 375:1–8 Available at: Google Scholar
  34. European Commission (2011) Commission implementing decision of 3 November 2011 on granting a derogation requested by Italy with regard to the regions of Emilia Romagna, Lombardia, Piemonte and Veneto pursuant to Council Directive 91/676/EEC concerning the protection of waters against pollution caused by nitrates from agricultural sources (2011/721/EU). Off J Eur Union 287:36–41 Available at: Google Scholar
  35. European Commission (2016) Commission Implementing Decision (EU) 2016/1040 of 24 June 2016 on granting a derogation requested by Italian Republic with regard to the Regions of Lombardia and Piemonte pursuant to Council Directive 91/676/EEC concerning the protection of waters against pollution caused by nitrates from agricultural sources (notified under document C(2016) 3820)Google Scholar
  36. Harter T, Davis H, Mathews M, Meyer R (2002) Shallow groundwater quality on dairy farms with irrigated forage crops. J Contam Hydrol 55(3-4):287–315. Google Scholar
  37. Hübner H (1986) Isotope effects of nitrogen in the soil and biosphere. In: Fritz P, Fontes JC (eds) Handbook of environmental isotope geochemistry, Vol 2b, the terrestrial environment. Elsevier, Amsterdam, pp 361–425Google Scholar
  38. Kelly WR, Panno SV, Hackley KC (2012) The sources, distribution, and trends of chloride in the waters of Illinois. Illinois State Water Survey, Prarie Research Institute, Champaign, p 67 (Mar, Report No.: B-74)Google Scholar
  39. Kendall C (1998) Tracing nitrogen sources and cycling in catchment. In: Kendall C, McDonnell JJ (eds) Isotope tracers in catchment hydrology. Elsevier, Amsterdam, pp 519–576. Google Scholar
  40. Kendall C, Elliott EM, Wankel SD (2007) Tracing anthropogenic inputs of nitrogen to ecosystems, chapter 12. In: Michener RH, Lajtha K (eds) Stable isotopes in ecology and environmental science, 2nd edition. Blackwell Publishing, Hoboken, pp 375–449. Google Scholar
  41. Kohn J, Soto DX, Iwanyshyn M, Olson B, Kalischuk A, Lorenz K, Hendry MJ (2016) Groundwater nitrate and chloride trends in an agriculture intensive area in southern Alberta, Canada. Water Qual Res J 51(1):47–59. Google Scholar
  42. Komor SC (1997) Boron contents and isotopic compositions of hog manure, selected fertilizers, and water in Minnesota. J Environ Qual 26(5):1212–1222. Google Scholar
  43. Korom SF (1992) Natural denitrification in the saturated zone: a review. Water Resour Res 28(6):1657–1668. Google Scholar
  44. Lasagna M, De Luca DA (2016) The use of multilevel sampling techniques for determining shallow aquifer nitrate profiles. Environ Sci Pollut Res 23:20431–20448. Google Scholar
  45. Lasagna M, De Luca DA, Sacchi E, Bonetto S (2005) Studio dell’origine dei nitrati nelle acque sotterranee piemontesi mediante gli isotopi dell’azoto. Giornale di Geologia Applicata 2:137–143Google Scholar
  46. Lasagna M, De Luca DA, Debernardi L, Clemente P (2013) Effect of the dilution process on the attenuation of contaminants in aquifers. Environ Earth Sci 70(6):2767–2784. Google Scholar
  47. Lasagna M, Caviglia C, De Luca DA (2014) Simulation modeling for groundwater safety in an overexploitation situation: the Maggiore Valley context (Piedmont, Italy). Bull Eng Geol Environ 73:341–355. Google Scholar
  48. Lasagna M, Franchino E, De Luca DA (2015) Areal and vertical distribution of nitrate concentration in Piedmont plain aquifers (North-western Italy). In: Lollino G et al (eds) Engineering geology for society and territory–volume 3, River Basins, reservoir sedimentation and water resources. Springer International Publishing, Switzerland, pp 389–392.–3–319-09054-2_81 Google Scholar
  49. Lasagna M, De Luca DA, Franchino E (2016a) Nitrate contamination of groundwater in the western Po Plain (Italy): the effects of groundwater and surface water interactions. Environ Earth Sci 75(3):240. Google Scholar
  50. Lasagna M, De Luca DA, Franchino E (2016b) The role of physical and biological processes in aquifers and their importance on groundwater vulnerability to nitrate pollution. Environ Earth Sci 75(11):961. Google Scholar
  51. Liao L, Green CT, Bekins BA, Böhlke JK (2012) Factors controlling nitrate fluxes in groundwater in agricultural areas. Water Resour Res 48:W00L09. Google Scholar
  52. Macko SA, Ostrom NE (1994) Pollution studies using nitrogen isotopes. In: Lajtha K, Michener RM (eds) Stable isotopes in ecology and environmental science. Blackwell Scientific Publishers, Oxford, pp 45–62Google Scholar
  53. MacQuarrie KTB, Sudicky EA, Robertson WD (2001) Numerical simulation of a fine-grained denitrification layer for removing septic system nitrate from shallow groundwater. J Contam Hydrol 52:29–55Google Scholar
  54. Mariotti A, Germon JC, Hubert P, Kaiser P, Letolle R, Tardieux A, Tardieux P (1981) Experimental determination of nitrogen kinetic isotope fractionation: some principles; illustration for the denitrification and nitrification processes. Plant Soil 62:423–430Google Scholar
  55. Ministry for Environment, Land and Sea, Ministry for Agriculture, Food and Forestry Policies, Regions of Piedmont, Lombardy, Veneto, Emilia-Romagna and Friuli Venezia Giulia (2010). Request from Italy for a derogation under paragraph 2(b) of Annex III to directive 91/676/EEC from the limit of 170 kilograms of nitrogen per hectare per year from livestock manure.
  56. Morris BL, Lawrence ARL, Chilton PJC, Adams B, Calow RC, Klinck BA (2003) Groundwater and its susceptibility to degradation: a global assessment of the problem and options for management. Early warning and assessment report series, RS. 03-3. United Nations Environment Programme, NairobiGoogle Scholar
  57. Nolan B, Stoner J (2000) Nutrients in groundwaters of the conterminous United States, 1992–1995. (2000). USGS staff—published research. Paper 59.
  58. Pennisi M, Adorni-Braccesi A, Andreani D, Gori L, Sciuto PF, Gonfiantini R (2013) ISOBORDAT: an online database on boron isotopes. Proc. Internat. Symp. Isotopes in Hydrology, Marine Ecosystems, and Climate Change Studies, Oceanographic Museum, Principality of Monaco, 27 March–1 April 2011. IAEACN-186-061Google Scholar
  59. Perotti L, Lasagna M, Clemente P, Dino GA, De Luca DA (2015) Remote sensing and hydrogeological methodologies for irrigation canal water losses detection: the Naviglio di Bra test site (NW-Italy). In: Lollino G et al (eds) Engineering geology for society and territory–volume 3, River Basins, reservoir sedimentation and water resources. Springer International Publishing, Switzerland, pp 19–22.–3–319-09054-2_4 Google Scholar
  60. Petitta M, Fracchiolla D, Aravena R, Barbieri M (2009) Application of isotopic and geochemical tools for the evaluation of nitrogen cycling in an agricultural basin, the Fucino Plain, Central Italy. J Hydrol 372(1-4):124–135. Google Scholar
  61. Postma D, Boesen C, Kristiansen H, Larsen F (1991) Nitrate reduction in an unconfined aquifer: water chemistry, reduction processes, and geochemical modeling. Water Resour Res 27(8):2027–2045. Google Scholar
  62. Re V, Sacchi E (2017) Tackling the salinity-pollution nexus in coastal aquifers from arid regions using nitrate and boron isotopes. Environ Sci Pollut Res 24(15):13247–13261. Google Scholar
  63. Regione Piemonte (2008) Carta dell’uso del suolo 1:500000. Available at: Accessed 29 July 2015
  64. 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. Google Scholar
  65. Sacchi E, Pilla G, Gerbert-Gaillard L, Zuppi GM (2007) A regional survey on nitrate contamination of the Po valley alluvial aquifer (northern Italy). Int. Symp. On advances in isotope hydrology and its role in sustainable water resources management, IAEA, Vienna 21-25 May 2007, IAEA-CN-151/34, vol., 2, 471-478Google Scholar
  66. Sacchi E, Acutis M, Bartoli M, Brenna S, Delconte CA, Laini A, Pennisi M (2013) Origin and fate of nitrates in groundwater from the central Po plain: insights from isotopic investigations. Appl Geochem 34:164–180. Google Scholar
  67. Sacco D, Zavattaro L, Grignani C (2006) Regional-scale predictions of agricultural n losses in an area with a high livestock density. Ital J Agron 4:689–703Google Scholar
  68. Saffigna PG, Keeney DR (1977) Nitrate and chloride in ground water under irrigated agriculture in Central Wisconsin. Groundwater 15(2):170–177. Google Scholar
  69. Sànchez-Pérez JM, Bouey C, Sauvage S, Teissier S, Antiguedad I, Vervier P (2003) A standardised method for measuring in situ denitrification in shallow aquifers: numerical validation and measurements in riparian wetlands. Hydrol Earth Syst Sci 7(1):87–96. Google Scholar
  70. Seiler RL (2005) Combined use of 15N and 18O of nitrate and 11B to evaluate nitrate contamination in groundwater. Appl Geochem 20(9):1626–1636. Google Scholar
  71. Silva SR, Kendall C, Wilkison DH, Ziegler AC, Chang CCY, Avanzino RJ (2000) A new method for collection of nitrate from fresh water and the analysis of nitrogen and oxygen isotope ratios. J Hydrol 228(1-2):22–36. Google Scholar
  72. Tirez K, Brusten W, Widory D, Petelet E, Bregnot A, Xue D, Boeckx P, Bronders J (2010). Boron isotope ratio (d11B) measurements in Water Framework Directive monitoring programs: comparison between double focusing sector field ICP and thermal ionization mass spectrometry. J Anal At Spectrom 25:964–974Google Scholar
  73. Vengosh A (1998) Boron isotopes and groundwater pollution. Water Environ News 3:15–16Google Scholar
  74. Vengosh A, Heumann KG, Juraske S, Kasher R (1994) Boron isotope application for tracing sources of contamination in groundwater. Environ Sci Technol 28(11):1968–1974. Google Scholar
  75. Vitoria L, Otero N, Soler A, Canals A (2004) Fertilizer characterization: isotopic data (N, S, O, C, and Sr). Environ Sci Technol 38(12):3254–3262Google Scholar
  76. Widory D, Kloppmann W, Chery L, Bonnin J, Rochdi H, Guinamant J (2004) Nitrate in groundwater: an isotopic multi-tracer approach. J Contam Hydrol 72:165–188Google Scholar
  77. Widory D, Petelet-Giraud E, Negrel P, Lafdoich B (2005) Tracking the sources of nitrates in groundwater using coupled nitrogen and boron isotopes: a synthesis. Environ Sci Technol 39(2):539–548. Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2017

Authors and Affiliations

  1. 1.Earth Sciences DepartmentTurin UniversityTurinItaly

Personalised recommendations