May be associated with the presence of sodium in drinking water when present in high concentrations. Often from saltwater intrusion, mineral dissolution, industrial and domestic waste. Deteriorates plumbing, water heaters, and municipal water-works equipment at high levels.
Cost basis is the original price paid for shares of a security plus or minus certain adjustments required by applicable tax rules such as adjustments with respect to reinvested distributions and sales charges.
The cost basis is what you paid for the stock + the commission. A quick example is you purchase 100 xyz stock @ $100 and pay the brokerage a $20 commission. Your basis would be $10,020. Other factors to consider when calculating cost basis are stock splits, dividends & special situations like a gift or inheritance.