What amount of silica requires treatment in well water?

[Goldenrule]

Hi there. We are building a house in the Pacific NW and will be on well water. Our well was drilled 2 years ago, and we recently had comprehensive water tests done. We can't seem to get any straight answers on when silica becomes problematic, i.e. etching glass, fixtures, etc. I know a whole-house reverse osmosis system is the only way to remove silica from water; however, I don't want to go that route if we don't have to. We could take a wait-and-see approach, but then the damage will have already been done, and from what I've been told, it's irreversible. We will have a glass shower enclosure and don't want it cloudy in a few years. Does anyone know at what level (in mg/L or ppm) silica crosses the threshold from being harmless to etching your household glass (and does it etch faucets/fixtures too)?

 

[Jadnashua]

It seems that silica sand (silicon dioxide, quartz) may be common in a newly drilled well. It will wear on things, as it is harder than many metals, and is the same hardness as glass. It can etch things because of mechanical action, i.e., sand blasting. IMHO, you need to filter it out. Depending on how small the particles are, would dictate the type and size of filter you need. It might go away after you've used the well for awhile, and washed away all of the loose particles created by the drilling process. It could be made worse, depending on where the pump is in relation to the bottom of the well, as some of the sand would just fall to the bottom of the well hole, but if the pump is too close, it can suck it up.

Somebody that deals with wells will probably have a better answer.

 

[Sponsor]

 

[Goldenrule]

It seems that silica sand (silicon dioxide, quartz) may be common in a newly drilled well. It will wear on things, as it is harder than many metals, and is the same hardness as glass. It can etch things because of mechanical action, i.e., sand blasting. IMHO, you need to filter it out. Depending on how small the particles are, would dictate the type and size of filter you need. It might go away after you've used the well for awhile, and washed away all of the loose particles created by the drilling process. It could be made worse, depending on where the pump is in relation to the bottom of the well, as some of the sand would just fall to the bottom of the well hole, but if the pump is too close, it can suck it up.

Somebody that deals with wells will probably have a better answer.

Okay, thank you. Our turbidity and total dissolved solids were pretty low, however. I think the silica is a product of what the water picks up flowing through old volcanic rock to the aquifer. You can't see it with the naked eye. Perhaps we will have the silica levels tested again since we have used a fair amount of water outside (not through our house plumbing yet, though). There seems to be a general lack of information out there about levels of silica, e.g. 10, 20, 30, 40, 50 mg/L being aesthetically harmful or not. The EPA doesn't regulate silica, so there is no help available there. Thanks again for your reply.

 

[Valveman]

I would try to develop the well by pumping it hard for a while. You need to get that cleaned out of the well as best as possible. Sure you can filter it once the water is pumped, but silica or sand will wear out a pump quickly. I like a long flow inducer or a Lakos Sub K over the pump for most sand problems, but I don't know how it will work with particles so small you can't see them. Worth a call to Lakos.