Getting the Lead Out
by Pure Water Annie
Gazette tech wizard Pure Water Annie tells you how to protect your drinking water from lead.
The most common advice for removing lead from drinking water tells you to remove the source of lead. This is excellent advice, but unfortunately home owners have no control over lead entering the home from external sources. Lead most often comes from piping. If the water supplier still has lead pipes in service, or if your home has old copper pipes with lead solder joints, that is probably your source of lead. “Removing” the lead in this case involves corrosion control through pH and alkalinity adjustment, adding calcium (e. g. with a calcite filter) to the water line, or using a phosphate-based corrosion inhibitor.
This sounds complicated, and it is. Most of these strategies must be done by the supplier and are outside the control of the individual home owner.
A common whole house strategy for lead removal that is sometimes recommended to home owners is using a standard ion exchange water softener. This, too, can be tricky, because flow rates have to be kept low, and often the source of lead can be in the home plumbing itself. If so, a softener, by removing the calcium from the water, can actually promote corrosion and leaching of lead and make the problem worse.
The best strategy is to treat only the drinking water. Here you have several good options.
Point of Use Treatment
There are carbon cartridges with excellent lead removal properties from reputable makers that can be used in countertop and undersink filters. These usually consist of a an ion exchange medium that is molded into the carbon. Such filters can be inexpensive and very effective.
Activated alumina, most often used for fluoride reduction, can be used as well for lead removal, but since its effectiveness is pH-dependent, be sure you know what you’re doing. KDF combined with carbon has also been shown to be very effective at removing lead, but results should be verified if you’re going to trust your life to it.
Another very effective way to remove lead from drinking water is with a steam distiller. Distillers work well, but they can be inconvenient, expensive to operate, and they often require lots of attention.
Without doubt, the best home treatment to assure lead-free drinking water is a reverse osmosis unit. RO serves as an excellent lead barrier and removes 95% or so of soluble lead. RO units are relatively inexpensive and easy to maintain.
Reverse osmosis by its nature removes 95% of lead from incoming water. RO is the most effective drinking water protection for the home.