MiniSipper: A New Concept for High-capacity, Long-duration, Automated In Situ Water Sampling
Presenter: Thomas Chapin of the USGS Denver office
Friday, June 14, 2013 at 10 AM
USGS Visitor Center (Reston: National Headquarters), 1C400
MiniSipper: A New Concept for High-capacity, Long-duration,
Automated In Situ Water Sampling
(Former Mendenhall Fellow)
Crustal Geophysics and Geochemistry Science Center, Denver, CO
Most environmental water quality monitoring studies rely on hand-collected “grab” samples for water sample collection. However, grab sampling is expensive with significant costs for personnel, equipment, vehicles and travel. Field costs can be especially high if the sampling site is remote, dangerous to access, or snowbound for many months of the year. Grab sampling typically provides a few samples per year and this low temporal resolution sampling rarely captures the details of major transient hydrologic processes such as storm, flood, or seasonal runoff events. Currently available automated samplers could provide water sampling at remote sites, but these samplers are typically large, heavy, collect 24 one liter samples, and are not well suited for operation in freezing conditions.
The USGS has developed a small, light, low-cost, high-capacity, in situ water sampler, the MiniSipper, to overcome the limitations of current automated water samplers. The MiniSipper injects 2 to 10 mL discrete or integrated water samples into a 500’ Telfon sample coil. Nitric acid is added to stabilize each sample and individual water samples are then separated with a gas bubble. Over 250 five mL water samples can be collected with <5% carryover. The MiniSipper collects samples in situ for up to 12 months unattended and even operates under ice for over-winter sampling. After recovery, samples are pumped out of the sample coil and analyzed by high sensitivity multi-element methods such as ICP-MS.
The MiniSipper provides long-duration high-resolution metal data for hydrologic and geochemical processes that are almost impossible to observe with currently available sampling methods. MiniSipper technology is very flexible and MiniSippers has been used for acid mine drainage studies (above and below ground), tracer studies (above and below ground) and for post-wildfire runoff studies. The Borehole MiniSipper is designed for well monitoring, fits down a 2” borehole, and collects weekly samples over an entire year. The MiniSipper has primarily been used for metal analysis but this technology should be applicable to other analytes of interest such as organics, pesticides, nutrients, etc. This presentation will: 1) give an overview of the MiniSipper instrumentation; 2) present results from high-resolution acid mine drainage and post-wildfire monitoring; and 3) discuss applications currently under development such as the Event Response MiniSipper and the Disaster Response MiniSipper. Bring your sampling needs, ideas and problems; perhaps the MiniSipper could offer a solution.