Solinst groundwater samplers
Groundwater sampling can be a challenging task that requires different tools for different applications. Solinst groundwater samplers offer the capability to obtain commonly needed representative samples of groundwater using different approaches of water withdrawal.
Solinst’s 425 Discrete Interval Sampler uses passive sampling to grab water from a specific depth. The 407 Bladder Pump enables continuous airtight low flow sampling. The 408 Double Valve Pump can continuously sample at variable rates.
“One sampler isn’t necessarily going to be for every site,” said Randy Blackburn, Solinst product manager.
Each has different means of fluid sampling. The 425 sampler relies on a manual air pump that pressurizes the sampler based on the water depth. “On the way down, no water can get into the sampler,” said Blackburn. “Once you hit your target depth you release the (air pressure) vent and water enters the sampler.”
Solinst provides formulas to determine how much pressure is required based on the depth of samples.
Once the 425 Discrete Interval Sampler collects liquid, users must reel the sampler to the surface and deposit fluids in a storage container.
The 407 Bladder Pump uses air pressure from bottled gas, like nitrogen or an air compressor, to collect samples. When the pump first enters fluid in the well, an internal Teflon bladder fills with water. Compressed air, regulated by a Solinst 464 Pump Control Unit, squeezes the bladder, slowly forcing the water up the sample line towards the surface until the bladder is empty. Then the pump controller vents, releasing a check ball at the bottom of the pump and sealing the sample line. The bladder fills and the cycle repeats.
The advantage to the bladder pumps is that they prevent air to water contact, making them ideal for volatile organic compound sampling. “The compressed air or bottled gas never comes in contact with the groundwater sample,” Blackburn said.
The 408 Double Valve Pump also uses compressed air to draw water from the well. The pump body, drive line, and sample line fill with water to hydrostatic level once in the well. Then air pressure engages a check ball, pressurizing the pump and forcing water up to the surface. Again, the 464 Pump Control Unit vents and pressurizes the system to continually draw water and push it to the surface.
Sampler applications depend on several factors including the depth of sampling, flow rates and sampling protocols.
The 425 sampler is ideal for grabbing a sample of water in a suspended column of fluids, which can be useful when one does not want to mix stratified layers of liquid. It also minimizes the extraction of volatile chemicals during the sampling process. Solinst offers discrete interval samplers rated to sample as deep as 500 feet.
The 407 and 408 pumps can maintain a slow constant flow of water from the pump to the surface. This can be ideal for when purge parameters are measured during low flow sampling as mandated by some regulatory agencies.
PVC versions of the 407 Bladder Pump can sample as deep as 100 feet. Solinst offers stainless steel bladder pumps rated to sample as deep as 500 feet.
Solinst’s 408 Double Valve pump can be used for low flow sampling and to provide higher flow rates when well yields are higher. PVC versions can sample as deep as 100 feet and stainless steel versions can sample as deep as 500 feet.
Solinst offers multiple groundwater sampling equipment options, each designed for different applications. Click here to see the full array of sampling pumps and their recommended use based on well diameter, depth range, flow rates, and budget.