sammyhydro11 said:
Speedbump is right about that acid solution. I also don't think the acid is going to work without a proper developement method. I would try pumping it first and see what you come up with.
Okay, yes and no ...
Following "Dump NW-100 pellets directly from container into well", here is what the NW-100 instruction sheet says:
Next, surge [the] solution.
In other words, the pellets are presumed to have dissolved into a solution after immersion and sinking to the bottom. Otherwise, there would be no solution to surge. And along with that, "John" (long-time owner at the local hardware store and pump repair shop even my grandfather used to frequent) has said the pellets are harmless until they hit water, and that the solution is heavier than water and will sink to the bottom even after the pellets have dissolved. However, he is not sure whether he would be able to ship the pellets to you without having to deal with HazMat issues.
With the solution in the well, the directions continue:
Agitation will spread solution's coverage over widest possible area and speed breakup of encrusting material. If start-stop pump action or other means of mechanical agitation are impractical, add a quantity of water equal to the volume of the screen so solution is forced through slot openings to contact the encrustant. Jetting by the recirculation method is not recommended because of the corrosive effect on the jetting pump and the hazard to personnel.
If you have much at all still coming out of your well, you are going to have difficulty getting the pellets to the bottom unless you are first able to evacuate the first few feet of casing and then quickly cap/seal it off after adding the pellets. But if you can do that, I would let it set for a few hours to let the solution reach the bottom, and I would then add a little water from the top and quickly connect some kind of push-and-pull pump or other device to agitate the solution out and in through the screen. At that point, I would again cap it off and let it set overnight and see what comes out in the morning! Oh, and John also said capping it off definitely will cause some pressure to build and push the solution into the screen. However, and without explanation, he winced just a bit when I told him we are dealing with 189' of 2" pipe.
If you want to use the pellets but cannot find them anywhere or get them shipped to you, let me know and we will make it happen. At about $30.00 each, John has three 4.5# jars on the shelf. The instruction sheet says 1/2 gallon for a 2" well, and the 4.5# jar appears to me to be a little less than a gallon. Personally, however, I would use at least two of those jars in my own well ... and I just now noticed this on the instruction sheet:
To treat unusually severe cases of encrustation, double the normal dosage [and the water later added to agitate the screen].