‘Shondra’ asked, “I live in a city that just sent out an annual water quality report and it says they add phosphates to our drinking water. Why do they do that? Is there a good reason for us to be drinking phosphates? Doesn’t sound like an essential vitamin or mineral to me.”
We talk about older infrastructure (i.e. water service lines) a lot on this site because many of the water service lines running from the water treatment plant out to individual homes contain copper and lead elements that over time tend to dissolve into the water passing through them.
While the presence of dissolved copper in the water supply generally poses no health risks in the quantities normally seen in the public water supply, it can result result in unwanted and VERY difficult to remove staining on fixtures in the home. Additionally, owners of swimming pools and hot tubs get warned constantly of the dangers of not neutralizing or removing dissolved metals (like copper) prior to adding chemicals after filling up their pool or tub… else risk some serious stain problems that will cost a lot of money and elbow grease to remove!
The presence of lead in water, however, does pose a serious health risk according to pretty much every water quality expert and health agency. The USEPA requires public water systems to take action to immediately reduce levels of dissolved lead when they reach or exceed 15ppb (parts per billion).
OK, so why add phosphates to the water supply?
By maintaining a certain level of phosphates in the water supply, public water systems reduce the amount of copper and lead that can leech into the water. In layman’s terms, the phosphates ‘coat’ the metal surfaces and thus limit its exposure to the water passing through the lines.
I have well water, so I’m safe, right?
Actually, you may have larger concerns than just exposure to copper and lead. Public water supplies get monitored for a large assortment of various chemicals, compounds and water quality parameters on an ongoing basis whereas no one monitors the quality of the water coming from your well.
Getting back to the matter of copper and lead in well water, though, both metals occur naturally in the environment and may show up in well water without warning. Additionally, older homes may still contain copper plumbing that has lead laden solder holding its joints and unions together.