Recommendations for filtering large amount of intermittent sediment from well water
We drilled a well in May of this year to replace our spring. It goes 545 ft deep. They hit rock (limestone, sandstone) at 17 feet. The casing goes down 20 feet as does the bentonite grout. Shortly after the well was installed, after a very heavy downpour, we had a lot of red clay-like sediment in the water, which cleared after a couple of days. Then this week after a couple days of steady rain the water became extremely muddy (looked like apple cider). It has cleared , gotten muddy again , then is clearing again now after running a lot of water from the hydrant connected directly at the well head. We have been assured by the well driller, and the sanitation engineer at the Health Dept that it could not be due to surface water, but is due to a disturbance deep in the ground water. We know now that we need a whole house system to filter the sediment. What we are wanting is recommendations for the type and micron size of the filters. We were thinking that a series of filters , going from larger micron size to smaller would be a good idea, but what sizes? and how many? The sediment appears to be a fine clay-like material. Thanks for your help.
A Lakos Separator is always good for sediment. This is a unit that is piped before the well tank and used centrifugal force to spin the water into a collection tube in at the bottom. They also make a similar one that can be installed directly on the pump and spins sediment down below the pump.
Also a whole house filter is always beneficial in my opinion whether you have sediment or not as a precautionary measure. I would start with a higher micron and try it out, you can always change to a lower micron filter if sediment is still present.
You have what is called, understatingly enough, "problem water". Because the conditions changes so radically and in varying consistencies, colors and length of time, etc., any one-unit system will probably have little overall effect or usefulness.
Contaminants that remain in suspension for more than a few minutes, let alone days, may not be easily removed by simple filtration. Colloids may require chemical treatment to flocculate before filtering. Colloidal iron often appears as you described.
A LAKOS is a great piece of equipment. The way I test for it is the 3/4 fill a 2 liter bottle of the tested water with heavy physical particles and swirl it as hard as I can and let it sit. What has dropped to the bottom in 15- 30 seconds can be removed by the LAKOS, including sand, metal flakes some vegetation, etc. What is still whirling around may pass through. I haven't put in that many and results may vary a little but it works WELL as an initial unit for many types of problem water.
Newly drilled wells sometime experience muddy conditions when a 'cavity' forms as water carries with it some freshly released earth. I would hope the muddiness passes soon. But newer cavities may break free. If surface water is intruding and causing this muddiness, then you have a technical problem that needs to be fixed.
You may need more than a graduated series of filters with reduced microns. For utility purposes your equipment should be at least adequate; for drinking water, more than adequate. But understanding (testing, monitoring, researching, etc.) your water is the key to success. Get it thoroughly tested.