This is not a safe solution…

This is not a safe solution and could have significant negative consequences.
The primary risks of using a Sequencing Batch Reactor (SBR) system at a ski resort relate to the challenges posed by highly seasonal flow variations, cold temperatures, and potential public health/environmental concerns if the treated effluent is reused for snowmaking.
Operational Risks
Highly Seasonal Flow and Load Variations: Ski resorts experience extreme fluctuations in wastewater flow between peak season and off-season, which can range by a ratio of 1 to 800. SBRs can be designed to handle shock loads, but if not properly managed, this variability can lead to:
Biomass Management Issues: It can be difficult to grow and maintain enough active biomass (microorganisms) during low-flow periods to handle the sudden, massive influx of wastewater when the season begins.
Hydraulic Overloading: Heavy rain or significant snowmelt events can rapidly increase flow into the plant, potentially leading to a "wash out" of the sludge blanket and operational failures, especially if the SBR is not designed with a "storm mode".
Process Instability: Inconsistent loading can make it difficult to maintain stable treatment results and achieve reliable nutrient removal, requiring continuous monitoring and adjustment of operational parameters.
Cold Climate Performance: Low wastewater temperatures in winter significantly slow down the metabolic and reproductive rates of the bacteria responsible for treatment.
Reduced Efficiency: This results in poorer breakdown of organic matter (BOD reduction) and a potential loss of nitrification (ammonia removal).
Physical Icing: Freezing temperatures can cause physical issues like icing of equipment, pipes, and aerators, which can damage the system and shut down operations.
Slower Recovery: If a process upset occurs, recovery in a cold weather system can take two to three times longer than in a warmer climate.
Automation and Maintenance: SBR systems rely heavily on automated valves, actuators, and decanters.
Equipment Malfunction: More automated components mean more potential points of failure, which can disrupt the treatment process and require specialized maintenance.
Environmental and Health Risks of Effluent Reuse
Many resorts explore using treated wastewater for snowmaking, which introduces additional risks:
Public Health Concerns: While advanced treatment significantly reduces pathogens, some can escape the process. If this snow is in areas with high human contact, particularly children, or where people might consume the snow (despite signage), it poses a potential health risk.
Contaminants of Emerging Concern: Treated wastewater can still contain trace amounts of pharmaceuticals and other micropollutants that current treatment processes do not fully eliminate. The effects of these compounds accumulating in the environment, especially on aquatic life after snowmelt, are an area of ongoing scientific study.
Environmental Accumulation: Reusing water for snowmaking can alter the local water cycle and soil chemistry.
Soil Salinity and Sodium: Long-term irrigation or snowmaking with treated wastewater can increase soil salinity and sodium levels, which can degrade soil structure, harm vegetation, and potentially contaminate groundwater.
Altered Ecosystems: The meltwater from artificial snow can have different impurity concentrations than natural snowmelt, potentially affecting local streams and aquatic ecosystems, with initial meltwaters often being the most concentrated.