What is the required separation between PCS and groundwater under Generic Remedy 1?

The required separation between the petroleum-contaminated soil (PCS) and groundwater under Generic Remedy 1 is crucial to ensure that contaminants do not leach into the groundwater, which can lead to environmental and health risks. In this context, maintaining a 3-foot separation is necessary as it provides a buffer zone that allows for the natural filtration and degradation processes to work effectively in the soil before reaching the groundwater. This separation helps protect groundwater quality and ensures compliance with regulatory measures designed to safeguard public health and the environment. It also aligns with best practices in environmental remediation, emphasizing the importance of effective contaminant management in soil treatment scenarios.