Hydrogeochemical signatures and human impact: A comprehensive analysis of groundwater quality on the semi-arid island of Curaçao

Study region: Island of Curaçao, Caribbean Sea Study focus: Groundwater is a critical resource for many Caribbean islands. This study assessed the groundwater quality (main and trace elements, E. coli) of Curaçao during 4 subsequent wet seasons (2020–2024). New hydrological insights for the region:...

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Main Authors: Mike R.J. Wit, Jessie-Lynn van Egmond, Titus P. Kruijssen, Victor F. Bense, Boris M. van Breukelen
Format: Article
Language:English
Published: Elsevier 2025-08-01
Series:Journal of Hydrology: Regional Studies
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Online Access:http://www.sciencedirect.com/science/article/pii/S2214581825003805
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author Mike R.J. Wit
Jessie-Lynn van Egmond
Titus P. Kruijssen
Victor F. Bense
Boris M. van Breukelen
author_facet Mike R.J. Wit
Jessie-Lynn van Egmond
Titus P. Kruijssen
Victor F. Bense
Boris M. van Breukelen
author_sort Mike R.J. Wit
collection DOAJ
description Study region: Island of Curaçao, Caribbean Sea Study focus: Groundwater is a critical resource for many Caribbean islands. This study assessed the groundwater quality (main and trace elements, E. coli) of Curaçao during 4 subsequent wet seasons (2020–2024). New hydrological insights for the region: Three main hydrochemical processes were identified with Principal Component Analysis (PCA): 1) seawater influence (median EC = 1900 µS/cm), 2) nutrient contamination, and 3) silicate weathering from altered basalts.Elevated median nitrate concentrations (all 206 samples = 35 mg/L) are highest in urban areas (102 mg/L) suggesting wastewater leakage from cesspits. Lower Cl/B mass ratios (550) in urban areas compared to natural vegetated (1000) areas, indicate a wastewater source derived from reverse osmosis drinking water relatively high in Boron. Enrichment of δ15N-NO3 and δ18O-NO3 versus wastewater signatures indicates considerable occurrence of denitrification. Phosphate concentrations remain low (∼0.1 mg/L), except for sites irrigated with large volumes of treated wastewater (>1 mg/L). Cl-B endmember mixing model showed 36 % wastewater contribution to groundwater, making it an important additional freshwater source given the semi-arid conditions. The findings underscore the value of comprehensive groundwater monitoring and the need for sanitation improvements. Addressing these challenges will benefit water management practices on Curaçao and similar islands. Additionally, it will improve groundwater quality, and groundwater-affected ecosystems, such as nearshore coral reefs.
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spelling doaj-art-0e7742c7fde948489cbaf7d8d4c842e82025-08-20T03:08:32ZengElsevierJournal of Hydrology: Regional Studies2214-58182025-08-016010255510.1016/j.ejrh.2025.102555Hydrogeochemical signatures and human impact: A comprehensive analysis of groundwater quality on the semi-arid island of CuraçaoMike R.J. Wit0Jessie-Lynn van Egmond1Titus P. Kruijssen2Victor F. Bense3Boris M. van Breukelen4Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Water Management, Delft 2600, the Netherlands; Corresponding author.Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Water Management, Delft 2600, the NetherlandsWageningen University and Research, Hydrology and Environmental Hydraulics Group, Wageningen 6708, the NetherlandsWageningen University and Research, Hydrology and Environmental Hydraulics Group, Wageningen 6708, the NetherlandsDelft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Water Management, Delft 2600, the NetherlandsStudy region: Island of Curaçao, Caribbean Sea Study focus: Groundwater is a critical resource for many Caribbean islands. This study assessed the groundwater quality (main and trace elements, E. coli) of Curaçao during 4 subsequent wet seasons (2020–2024). New hydrological insights for the region: Three main hydrochemical processes were identified with Principal Component Analysis (PCA): 1) seawater influence (median EC = 1900 µS/cm), 2) nutrient contamination, and 3) silicate weathering from altered basalts.Elevated median nitrate concentrations (all 206 samples = 35 mg/L) are highest in urban areas (102 mg/L) suggesting wastewater leakage from cesspits. Lower Cl/B mass ratios (550) in urban areas compared to natural vegetated (1000) areas, indicate a wastewater source derived from reverse osmosis drinking water relatively high in Boron. Enrichment of δ15N-NO3 and δ18O-NO3 versus wastewater signatures indicates considerable occurrence of denitrification. Phosphate concentrations remain low (∼0.1 mg/L), except for sites irrigated with large volumes of treated wastewater (>1 mg/L). Cl-B endmember mixing model showed 36 % wastewater contribution to groundwater, making it an important additional freshwater source given the semi-arid conditions. The findings underscore the value of comprehensive groundwater monitoring and the need for sanitation improvements. Addressing these challenges will benefit water management practices on Curaçao and similar islands. Additionally, it will improve groundwater quality, and groundwater-affected ecosystems, such as nearshore coral reefs.http://www.sciencedirect.com/science/article/pii/S2214581825003805HydrochemistryGroundwater pollutionSIDSUrban wastewaterSource apportionmentNitrate stable isotopes
spellingShingle Mike R.J. Wit
Jessie-Lynn van Egmond
Titus P. Kruijssen
Victor F. Bense
Boris M. van Breukelen
Hydrogeochemical signatures and human impact: A comprehensive analysis of groundwater quality on the semi-arid island of Curaçao
Journal of Hydrology: Regional Studies
Hydrochemistry
Groundwater pollution
SIDS
Urban wastewater
Source apportionment
Nitrate stable isotopes
title Hydrogeochemical signatures and human impact: A comprehensive analysis of groundwater quality on the semi-arid island of Curaçao
title_full Hydrogeochemical signatures and human impact: A comprehensive analysis of groundwater quality on the semi-arid island of Curaçao
title_fullStr Hydrogeochemical signatures and human impact: A comprehensive analysis of groundwater quality on the semi-arid island of Curaçao
title_full_unstemmed Hydrogeochemical signatures and human impact: A comprehensive analysis of groundwater quality on the semi-arid island of Curaçao
title_short Hydrogeochemical signatures and human impact: A comprehensive analysis of groundwater quality on the semi-arid island of Curaçao
title_sort hydrogeochemical signatures and human impact a comprehensive analysis of groundwater quality on the semi arid island of curacao
topic Hydrochemistry
Groundwater pollution
SIDS
Urban wastewater
Source apportionment
Nitrate stable isotopes
url http://www.sciencedirect.com/science/article/pii/S2214581825003805
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