ASTM E3400

ASTM E3400 is the standard practice for collecting storm based paired influent and effluent flow weighted composite water samples using automated samplers. It provides a focused framework for gathering samples that reflect changing flow conditions during storm events, which can improve the reliability of water quality evaluations. For laboratories, utilities, and environmental monitoring teams, this ASTM standard supports more consistent sample collection and helps align field practices with a common technical approach.

Overview of ASTM E3400

The purpose of ASTM E3400 is to guide the collection of paired influent and effluent samples during storm-based conditions using automated samplers. By emphasizing flow weighted composite sampling, the practice is designed to better represent water quality over the course of a storm event rather than a single moment in time. This makes the standard useful when comparing entering and leaving flows and when documenting performance under variable conditions. It is a practical technical reference for structured sampling workflows.

Common use cases of ASTM E3400

This practice is commonly used in stormwater and wastewater monitoring programs where paired influent and effluent data are needed for event-based assessment. It may also support field sampling plans that rely on automated samplers to collect composite samples over a storm duration. ASTM E3400 is relevant when organizations need a repeatable approach for comparing flow-weighted sample results, documenting system behavior during storms, or supporting technical reviews of water quality performance.

Benefits of using ASTM E3400

Using ASTM E3400 can improve consistency in how storm event samples are collected and documented. That consistency supports compliance efforts, data comparability, and quality control across monitoring projects. The practice also helps reduce ambiguity in field procedures by offering a recognized approach for paired influent and effluent sampling with automated equipment. For procurement and project planning, it gives buyers and specifiers a clear ASTM standard to reference when defining sampling expectations.

• Storm-based paired influent and effluent sampling
• Flow weighted composite collection
• Automated sampler workflow
• Event-focused water quality monitoring
• Consistent technical reference for field practice