The ASTM D4448 01 2019  Standard Guide for Sampling Ground-Water Monitoring Wells is a standard guide that provides procedures and recommendations for sampling groundwater monitoring wells to obtain representative water samples for environmental analysis. It outlines best practices for collecting, handling, and preserving groundwater samples to ensure data accuracy and reliability. The guide covers essential topics such as purging techniques, equipment selection, decontamination, and sample containers. While it does not prescribe specific methods, it serves as a general framework to help environmental professionals design and implement consistent and scientifically sound sampling programs in compliance with regulatory or project-specific requirements.