Assessing intermittent saline inflows in urban water systems

Area of Science:

• Environmental Engineering
• Urban Water Management
• Coastal Engineering

Background:

• Urban water drainage systems are crucial for transporting wastewater and stormwater.
• Saline water intrusion poses significant risks to coastal drainage systems, impacting infrastructure and treatment processes.
• Early detection and management of saline inflows are essential to prevent performance deterioration.

Purpose of the Study:

• To develop and validate a procedure for diagnosing undue saline inflows in urban water drainage systems.
• To assess the magnitude, acceptance levels, and performance contribution of saline inflows.
• To propose tailored management options based on diagnostic outcomes.

Main Methods:

• Selection of contextual factors and performance indicators with reference values.
• Determination of saline inflow magnitude and its impact on system performance.
• Application of the diagnostic procedure to a case study in a coastal urban area.

Main Results:

• The diagnostic procedure effectively identifies and quantifies saline inflows.
• Saline volumes entering the system were found to be substantial (nearly 30%) in the case study.
• Identified issues include corrosion, wastewater treatment plant operational challenges, and concrete degradation.

Conclusions:

• The developed procedure provides a reliable method for assessing saline water intrusion in drainage systems.
• Timely intervention based on this diagnosis can mitigate negative impacts on infrastructure and treatment efficiency.
• Management strategies encompassing organizational, operational, and structural actions are crucial for addressing saline inflow problems.