Lead Contamination in Water

For the most part, lead does not come from natural sources such as surface or groundwater. Therefore, it does not originate from your local water treatment plant. The source of lead contamination in drinking water is primarily from the pipes, faucets or solder used in your home’s plumbing. Many older homes still use lead pipes from the street and homes built prior to 1988 likely used lead solder to connect copper pipes. Lead, when contacted with water, can corrode and cause contamination. Factors such as low pH (acidity), dissolved oxygen and low mineral content (soft water) can increase lead corrosion.

There is no known beneficial effect of lead on humans or animals. Long term exposure to lead at levels as low as 1 mg/L can have severe effects to the body. It has been shown that serious damage to the brain, nervous system, red blood cells and kidneys can occur. Those at most risk are small children and pregnant woman. Children and infants are especially affected since they are still growing and absorb lead easier than adults. The same goes for the fetus. Studies have shown that prolonged exposure to lead can adversely affect the mental and physical development of a child. Behavioral issues have also been reported.

The action levels that were established for these two metals are lead < 15 ppb and copper < 1.3 ppm. Optimum Corrosion Control Treatment (OCCT) criteria were also established; however this has been difficult for the EPA to govern.

Therefore, to address the lead and copper issue further, a consortium was created by the EPA with NSF setting up the Standard 60 guideline for chemicals that can be used for safe treatment within drinking water distribution systems. Since 1992, various chemical treatment programs have been tested throughout the United States with the best results stemming from the “blended phosphate” technology.

Through this “blended phosphate” technology, municipal drinking water systems can easily meet the lead and copper established guidelines while addressing additional issues such as: A) the control of biofilm development and B) the maintenance of system design “C factors”.

The benefits of implementing a “blended phosphate” program are numerous since the combined polyphosphate and orthophosphate chemistry provides a synergistic effect that compliments the needs of both corrosion and deposition control within distribution systems.

There are other chemical treatment programs that also meet the NSF Standard 60 guideline for drinking water. These treatment programs are referred to as zinc-orthophosphate program or straight orthophosphate program. Unfortunately, they typically do not provide good control of biofilm development and/or “C factor”. These two programs initially were used on some distribution systems since cost appeared to be an advantage; however, these cost savings generally are not realized.

Carus Corporation offers all of the treatment programs reviewed above for removing lead contamination in water. We welcome you to contact our corporate headquarters or our sales representative designated for your area, to discuss these treatment programs in greater detail. We are confident that our vast NSF approved product listing will meet your system needs.