Clever device for sampling water quailty

The Falling Stage Sampler is designed to take water samples from creeks and rivers after rain.

The Falling Stage Sampler is designed to take water samples from creeks and rivers after rain.

A simple device able to accurately take water samples from creeks and rivers after rain has been recognised as making a significant contribution to salinity research in Australia.

Designed by NSW Department of Primary Industries salinity researchers, the $50 ‘Falling Stage Sampler’ was chosen as a finalist in this year’s prestigious Engineers Australia National Salinity Prize.

The prompt for the design was the fact that in areas where salinity is a problem, stream chemistry often changes dramatically between peaks and falls in streams after rain.

Collecting water quality data is often inefficient in these conditions – and the only samplers able to accurately sample stream water during the “falling stage” after a stream has peaked cost in the vicinity of $6 000.

The DPI design was developed by the department’s ‘Key Sites’ salinity team, which is monitoring salinity in key catchments across NSW.

Technical officer Chris McCulloch says the ‘Falling Stage Sampler’ can be produced from cheap, non-corrosive materials and its low cost means that more can be placed in the field and a greater range of data can be collected.

“The sampler consists of a sample bottle that is mounted in a pivoting cradle controlled by a locking mechanism.

“In this position, the sampler is triggered by rising water and is ready to sample when the water level falls. In the locked position it will not be contaminated by rain or by rising water.”

Mr McCulloch said stream flows are a good indicator of the health of catchments upstream, and that monitoring stream flow was a vital part of research into salinity.

“Results from stream flow monitoring can be used to develop action plans for managing salinity problems”, he said.

Mr McCulloch said there is potential for the sampler to also be used for irrigation and environmental monitoring.

Further tests are being conducted, with a view to the ‘Falling Stage Sampler’ being made more widely available.