When contemplating the use of HydraSleeves for groundwater sampling, SIZE DEFINITELY DOES MATTER!
Sample volume size, well diameter size, well screen size, casing size
All of these sizes are critical details when using any no-purge sampling technique. So which size is variable? Which of these sizes can be manipulated fairly easily?
When visiting a ground
water sampling site, the wells are typically already set. So the well diameter, screen and casing are already fixed sizes. They cannot easily be changed.
The one size that can be changed from this equation is the sample volume requirements. This item is typically set by the lab and is also typically exaggerated. Keep in mind that labs usually ask for 2 to 4 times more than what they actually need.
The sample volume requirements are usually predetermined and they are going ask for as much as they possibly can, to cover for spillage, errors and other unfortunate situations that might arise. Sometimes it seems they think that it's as easy as turning on your kitchen faucet.
Well, the HydraSleeve makes the collection process simple, but this simplicity has it's limitations and as the sample volumes go up the degree of difficulty also increases.
Just like you can't get blood out of a turnip - you cannot get 5 liters of sample volume from a 2-inch diameter, 10-foot well screen.
Our line of SuperSleeve HydraSleeves are designed to gather as much sample volume as technically possible from a 2-inch, Schedule 40 well. Using SuperSleeves we can collect 4 liters from a 10-foot screen; 2 liters from a 7-foot screen; and 1 liter from a 4-foot screen. Any more from less simply cannot be accommplished using no-purge samplers.
So, when planning your groundwater sampling events and when communicating the requirements with your lab; please remember SIZE DOES MATTER and sample volume sizes are usually negotiable.
Reducing your sample volume size will also make you much happier in the field. As sample volumes go up, HydraSleeve complexity goes up. Lets look at what is possible to collect from a 2-inch schedule 40 well with 10 feet of saturated screen. The easiest amount of sample volume to collect is 600-1000 mls using a standard HS-2 or HS-2-1L HydraSleeve; the most difficult to collect is 4 liters using the giant TurboSleeve SuperSleeve.
Happiness is small sample volumes and simple HydraSleeve assemblies!