There's lots of iron pyrite (fools gold) in Georgia, and lots of clay (I believe high in Iron content). The orange staining is possibly due to clay. I'm not the expert, but it sounds like somewhere that ground water is contaminating the pool- explains the orange stain (from the clay) and the gold flakes (iron pyrite). Is there anyway rain is washing into the pool? Or any way that your "spring" is more than a spring ( like, flooding around your filter/pump, so spring water is getting into the system there)?