In‐Stream Nitrogen Dynamics in a Point Source Influenced Headwater Stream During Baseflow Conditions
Abstract Hydrochemical signatures are often traced back to their original sources using data collected at catchment outlets. However, this approach introduces uncertainties, as signals may add up, cancel each other out, or be subject to transformation processes. Specifically rural point sources, suc...
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| Format: | Article |
| Language: | English |
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Wiley
2024-09-01
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| Series: | Water Resources Research |
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| Online Access: | https://doi.org/10.1029/2023WR036672 |
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| author | Caroline Spill Lukas Ditzel Matthias Gassmann |
| author_facet | Caroline Spill Lukas Ditzel Matthias Gassmann |
| author_sort | Caroline Spill |
| collection | DOAJ |
| description | Abstract Hydrochemical signatures are often traced back to their original sources using data collected at catchment outlets. However, this approach introduces uncertainties, as signals may add up, cancel each other out, or be subject to transformation processes. Specifically rural point sources, such as communal wastewater treatment plants (WWTPs), are often overlooked and remain poorly understood in terms of their (local) impact, on water quality and quantity dynamics. We equipped a point source‐influenced headwater catchment with a comprehensive measurement setup, to directly trace the different hydrochemical signals. Statistical approaches were used to address c‐Q relationships and hydrochemical drivers for nutrient export upstream, downstream and within the WWTP during baseflow conditions. Groundwater infiltration into the old and leaky sewer system as well as rainwater collected via the combined sewer system were found to significantly alter processes within the WWTP, resulting in highly variable effluent nutrient concentrations. Ammonium introduced by the WWTP is rapidly transformed in the stream, leading to increasing nitrate concentrations further downstream. The combination of processes introduced by the WWTP overlap the dilution and (non‐significant) chemostatic patterns of the upstream nitrate‐discharge relationship, leading to enrichment patterns shortly after, and mainly diluting patterns 290 m downstream of the WWTP. Regarding maximum nutrient concentrations, dry periods during autumn were particularly critical, as the WWTP introduced high ammonium concentrations, which coincided with high nitrate concentrations from the catchment and a minimal dilution potential of the stream. Our study demonstrates the importance of incorporating all nutrient sources into catchment analyses, to facilitate successful management decisions. |
| format | Article |
| id | doaj-art-5f37b07e3f8a45a3894d77f109b5e53e |
| institution | OA Journals |
| issn | 0043-1397 1944-7973 |
| language | English |
| publishDate | 2024-09-01 |
| publisher | Wiley |
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| series | Water Resources Research |
| spelling | doaj-art-5f37b07e3f8a45a3894d77f109b5e53e2025-08-20T02:36:34ZengWileyWater Resources Research0043-13971944-79732024-09-01609n/an/a10.1029/2023WR036672In‐Stream Nitrogen Dynamics in a Point Source Influenced Headwater Stream During Baseflow ConditionsCaroline Spill0Lukas Ditzel1Matthias Gassmann2Department of Hydrology and Substance Balance University of Kassel Kassel GermanyDepartment of Hydrology and Substance Balance University of Kassel Kassel GermanyDepartment of Hydrology and Substance Balance University of Kassel Kassel GermanyAbstract Hydrochemical signatures are often traced back to their original sources using data collected at catchment outlets. However, this approach introduces uncertainties, as signals may add up, cancel each other out, or be subject to transformation processes. Specifically rural point sources, such as communal wastewater treatment plants (WWTPs), are often overlooked and remain poorly understood in terms of their (local) impact, on water quality and quantity dynamics. We equipped a point source‐influenced headwater catchment with a comprehensive measurement setup, to directly trace the different hydrochemical signals. Statistical approaches were used to address c‐Q relationships and hydrochemical drivers for nutrient export upstream, downstream and within the WWTP during baseflow conditions. Groundwater infiltration into the old and leaky sewer system as well as rainwater collected via the combined sewer system were found to significantly alter processes within the WWTP, resulting in highly variable effluent nutrient concentrations. Ammonium introduced by the WWTP is rapidly transformed in the stream, leading to increasing nitrate concentrations further downstream. The combination of processes introduced by the WWTP overlap the dilution and (non‐significant) chemostatic patterns of the upstream nitrate‐discharge relationship, leading to enrichment patterns shortly after, and mainly diluting patterns 290 m downstream of the WWTP. Regarding maximum nutrient concentrations, dry periods during autumn were particularly critical, as the WWTP introduced high ammonium concentrations, which coincided with high nitrate concentrations from the catchment and a minimal dilution potential of the stream. Our study demonstrates the importance of incorporating all nutrient sources into catchment analyses, to facilitate successful management decisions.https://doi.org/10.1029/2023WR036672wastewater treatment plant (WWTP)nitrateammoniumc‐Q relationshipchemodynamicsnet uptake rate |
| spellingShingle | Caroline Spill Lukas Ditzel Matthias Gassmann In‐Stream Nitrogen Dynamics in a Point Source Influenced Headwater Stream During Baseflow Conditions Water Resources Research wastewater treatment plant (WWTP) nitrate ammonium c‐Q relationship chemodynamics net uptake rate |
| title | In‐Stream Nitrogen Dynamics in a Point Source Influenced Headwater Stream During Baseflow Conditions |
| title_full | In‐Stream Nitrogen Dynamics in a Point Source Influenced Headwater Stream During Baseflow Conditions |
| title_fullStr | In‐Stream Nitrogen Dynamics in a Point Source Influenced Headwater Stream During Baseflow Conditions |
| title_full_unstemmed | In‐Stream Nitrogen Dynamics in a Point Source Influenced Headwater Stream During Baseflow Conditions |
| title_short | In‐Stream Nitrogen Dynamics in a Point Source Influenced Headwater Stream During Baseflow Conditions |
| title_sort | in stream nitrogen dynamics in a point source influenced headwater stream during baseflow conditions |
| topic | wastewater treatment plant (WWTP) nitrate ammonium c‐Q relationship chemodynamics net uptake rate |
| url | https://doi.org/10.1029/2023WR036672 |
| work_keys_str_mv | AT carolinespill instreamnitrogendynamicsinapointsourceinfluencedheadwaterstreamduringbaseflowconditions AT lukasditzel instreamnitrogendynamicsinapointsourceinfluencedheadwaterstreamduringbaseflowconditions AT matthiasgassmann instreamnitrogendynamicsinapointsourceinfluencedheadwaterstreamduringbaseflowconditions |