DRINKING WATER EPA HEAVY METALS HUMAN HEALTH LEAD MATERIALS OF CONSTRUCTION MUNICIPAL WATER ORGANICS TOC

Abstract

“Get the lead out!” is an expression that can be interpreted two ways. As an idiom, this phrase essentially means “hurry up” or “go faster”. In the context of water, it suggests removing lead contamination from drinking water because of its harmful effect on human health.  

Lead contamination in drinking water recently gained high-profile status after reports surfaced that traces of the heavy metal had been found in drinking water in Flint, MI. The source of this contamination has been blamed on the city switching from the Detroit water supply to using the Flint River as its source. The Flint River water had higher levels of chlorides and the city did not use any corrosion control treatments to protect distribution piping. As a result, the higher chloride levels reacted with the lead service piping to houses and resulted in lead being released into residential drinking water supplies.

Briefly, the U.S. Environmental Protection Agency (EPA) lists lead as a heavy metal that is toxic to human health. The agency also includes mercury, chromium, cadmium, and arsenic, among other heavy metals that can harm humans and accumulate in the food chain. 

Now, one might ask why lead piping is even being used in the 21st century. Lead’s use in water pipes pretty much ended by World War II, but it was popular going back to Roman times. But, even today, pipes made from lead can still be found in older sections of cities. Besides these antiquated pipes, lead-tin solder was used for many years to join copper piping sections, and can also leach into water.  

Consequently, lead piping in municipal systems supports the argument for investing in infrastructure replacement, a topic that has received much attention for the last several years at the private and governmental levels. 

In reaction to this problem, Michigan Gov. Rick Snyder recently endorsed a plan for stricter state guidelines setting a maximum of 10 parts per billion (ppb) for lead in drinking water, which is lower than the EPA’s current standard of 15 ppb. Additionally, at the state and federal level work is underway to provide money to help pay for replacing lead service lines.

Now, one might reasonably ask: “What does any of this have to do with high-purity and industrial water?”

Actually, quite a lot. On the pharmaceutical side, facilities located in the United States are required to use a feedwater source that meets the drinking-quality standards of the EPA. So, it goes without saying that lead contamination in an incoming supply to a pharmaceutical facility or food and beverage plant would create a treatment headache. This would also be true for other water impurities. 

Now, other factors besides infrastructure replacement also impact water drinking water quality. In areas where the watershed flows through deciduous forests, there can be spikes in total organic carbon (TOC) levels in the fall months after tree leaves fall. Another example can come in agricultural areas where farming activity will cause elevated urea levels in water sources going to microelectronics plants, which has been documented in past Ultrapure Water articles.  

So, in essence municipal water quality problems such as have occurred in Flint point to the need for high-purity and industrial facilities plant operators to always be aware of incoming water quality and not assume the feedwater source will always meet the stated quality. Therefore, the key takeaway is that industrial plant water system operators need to have the treatment technologies at their disposal to address unexpected spikes in organics, heavy metals, or other contaminants that may harm operations of the in-plant users of the treated high-purity or process water.

In the case of the lead problem in Flint, the problem also gives marketing ammunition to companies active in the home drinking water market, which includes water softeners, point-of-use faucet filters, and other treatment technologies.

— Mike Henley

Background Sources

Arai, N.; Fujishima, S.; Iizumi, T.; Yokoi, I. “Trace Urea Removal Technology for High-Purity Water Quality Improvement”, Ultrapure Water 29(12), p. 9 (November/December 2012).

Dolan, M. “Flint trains up, Gets Ready to Replace its Lead Pipe”, Detroit Free Press, accessed at: www.freep.com (March 3, 2016).

Egan, P.; Dolan, M. “Snyder Pushes for Toughest Lead Test Rules in U.S.”, Detroit Free Press, accessed at: www.freep.com (April 15, 2016).

Fonger, R. “Elevated Lead Found in more Flint Kids after Water Switch, Study Finds”, The Flint Journal, accessed at: www.mlive.com (article date: Sept. 24, 2015).

Rydjewski, J.; Carr, G. “Advanced Organics Oxidation - Removing Urea from High-Purity Water”, Ultrapure Water 20(11), p. 20 (November 2003).     

U.S. Environmental Protection Agency, “Drinking Water Technical and Legal Terms”, available at www3.epa.gov (accessed April 2016).

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