The Composite Water Sampler is a rugged, programmable automatic sampler engineered to collect representative time- or flow-weighted automatic composite sampler from rivers, wastewater, stormwater, and industrial discharges. Its corrosion-resistant housing, inert tubing, and calibrated pump minimize contamination while precise timing and volume control ensure reproducible composite profiles. Available with refrigerated enclosures, large bottle capacity, and battery or mains power options, it supports extended field deployments and regulatory monitoring programs. An intuitive interface, data-logging capability, and easy-to-service modular components simplify operation and maintenance, delivering reliable, high-quality composite sampling wastewaters for compliance and research applications.