How should water and wastewater biological treatment systems be adapted for climate change impacts?

Climate change impacts biological treatment through multiple pathways requiring adaptation. Temperature effects: Warmer temperatures increase microbial activity but reduce oxygen solubility; altered community composition; potential for harmful algal blooms in ponds; ammonia toxicity increases at higher pH/temperature. Adaptation: enhanced aeration, temperature-tolerant organisms, covered systems. Precipitation changes: Intense storms cause I/I surges, dilute influent, hydraulic overload; drought concentrates contaminants. Adaptation: equalization, green infrastructure, reuse expansion, flexible designs. Sea level rise: Saltwater intrusion affects treatment biology; coastal facility flooding. Adaptation: elevated facilities, salt-tolerant treatment, relocations. Extreme events: Heat waves, hurricanes damage infrastructure; power outages. Adaptation: resilient design, backup power, decentralization. Changing source water: Agricultural runoff, algal blooms affect source quality for drinking water treatment. Adaptation: enhanced pretreatment, alternative sources. Planning approaches: Climate risk assessments; scenario planning for multiple futures; nature-based solutions; flexible/modular infrastructure; monitoring for early warning; regional coordination. Biological systems often more resilient than chemical/physical but require proactive management for climate extremes.