ARS | Publication request: A LOW-COST COMPOSITE WATER SAMPLER FOR DRIP AND STREAM FLOW

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 12, 2002
Publication Date: January 6, 2003
Citation: MALONE, R.W., BONTA, J.V., LIGHTELL, D.R. A LOW-COST COMPOSITE WATER SAMPLER FOR DRIP AND STREAM FLOW. APPLIED ENGINEERING IN AGRICULTURE. 2003. v. 19(1). p. 59-61.

Interpretive Summary: It is important to collect flow weighted (composite) water samples for water quality analysis when chemical concentrations change over time. The number of sampling locations, however, is often limited because of the cost of composite samplers. Furthermore, few samplers have been developed for collection of both drip and continuous streaming flow as found from tile drains, large monolith lysimeters (large blocks of soil), and springs. Therefore, an inexpensive slot sampler was developed to collect drip and continuous streaming flow (0.5 and 200 mL/min) and its field/lab performance was monitored. The designed sampler collected approximately 2.0% of flow with a sampler catch coefficient of variation between trials of less than 5%. This allows total flow rate to be estimated and flow weighted samples for water quality analysis to be collected. This sampler will enable field scientists to inexpensively estimate total flow and collect flow weighted samples from numerous locations.

Technical Abstract: The collection of flow proportional samples when flow rates range from slow drip flow to slow stream flow is important in hydrology. A slot sampler was modified for this purpose and its field/lab performance was monitored. The major design criteria include: function for flow rates between 0.5 and 200 mL/min; minimize sampler catch variance between trials; allow total flow volume estimate from sampler catch volume; compact in size; useful in remote conditions; low cost; low maintenance; and easily constructed from readily obtainable materials. The designed sampler collected approximately 2.0% of flow with a sampler catch coefficient of variation between trials of less than 5%. This allows total flow rate to be estimated and flow proportional samples for water quality analysis to be collected.