Scholarlink

<p>Groundwater provides a critical buffer for urban water security, yet contamination by nitrate from deteriorating sewer networks poses a persistent and globally underestimated threat. Unlike agricultural pollution, urban-derived nitrate is sustained by diffuse, chronic leakage from buried infrastructure, producing plumes that can persist for decades. Here, coupled groundwater flow and solute transport models (MODFLOW–MT3D) were applied to simulate 30-year scenarios of aquifer response in a Brazilian city where a nitrate plume exceeding 1.5&#xa0;km<sup>2</sup> has been sustained for over 20 years. Modeled results revealed that maintaining current leakage rates (~ 11%) stabilizes contamination at concentrations above drinking-water standards, while increases to 15–20% accelerate plume migration into deeper aquifer zones, further compromising supply wells. Conversely, halving leakage reduces nitrate below potability thresholds within 17 years, while complete source cessation leads to near-total aquifer recovery within 23 years. Managed pumping from intermediate zones enhances vertical mixing, dilutes concentrations, and slows plume expansion, highlighting the dual role of infrastructure maintenance and groundwater operations in restoring water quality. These findings demonstrate that urban aquifers are not irreversibly degraded, but their recovery depends on proactive interventions. By linking long-term contaminant fate with actionable management, this work provides a transferable framework for assessing the resilience and recovery potential of nitrate-impacted aquifers worldwide.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Sewer leakage as the main cause of multi-decadal nitrate plumes in a small tropical city

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月27日

查看全文
  • Carlos Henrique Gil Marques,
  • Ricardo Hirata,
  • Rafael Terada,
  • Bruno Conicelli,
  • Alexandra Suhogusoff,
  • Israel Carranco

摘要

Groundwater provides a critical buffer for urban water security, yet contamination by nitrate from deteriorating sewer networks poses a persistent and globally underestimated threat. Unlike agricultural pollution, urban-derived nitrate is sustained by diffuse, chronic leakage from buried infrastructure, producing plumes that can persist for decades. Here, coupled groundwater flow and solute transport models (MODFLOW–MT3D) were applied to simulate 30-year scenarios of aquifer response in a Brazilian city where a nitrate plume exceeding 1.5 km2 has been sustained for over 20 years. Modeled results revealed that maintaining current leakage rates (~ 11%) stabilizes contamination at concentrations above drinking-water standards, while increases to 15–20% accelerate plume migration into deeper aquifer zones, further compromising supply wells. Conversely, halving leakage reduces nitrate below potability thresholds within 17 years, while complete source cessation leads to near-total aquifer recovery within 23 years. Managed pumping from intermediate zones enhances vertical mixing, dilutes concentrations, and slows plume expansion, highlighting the dual role of infrastructure maintenance and groundwater operations in restoring water quality. These findings demonstrate that urban aquifers are not irreversibly degraded, but their recovery depends on proactive interventions. By linking long-term contaminant fate with actionable management, this work provides a transferable framework for assessing the resilience and recovery potential of nitrate-impacted aquifers worldwide.