It may seem almost magical: Water flows from the faucet when we turn the handle… But problems lurk behind an aging water system.
In towns like Flint, Michigan, the water from the faucet contains lead.
The dynamic chemistry of water that allows life to flourish can also cause illness and even death.
Water Use-One Instance Too Often?
Earth hosts life, for the most part, because we have flowing water; the properties of water allow the falling rain to nourish and encourage life.
Water on Earth goes through a cycle known as the hydrological cycle. This cycle has helped to build both snow-capped mountains and dry desert vistas, and has allowed humanity to populate the Earth. By the time it reaches our faucets, however, it may contain harmful elements.
To keep drinking water potable, or safe, water agencies in the United States resort to a generalized formula: chlorination and conditioning.
Chlorinating water to remove bacteria, and conditioning it, in many instances, to assure clean flow through plumbing. However, generalized formulas do not fit all situations as they arise. The poisoned water in places like Flint, Michigan illustrates that point well.
Lead Water Pipes
Many water pipes in the U.S. are comprised of the element Pb (lead) and other metals because these pipes can resist most instances of non-potable, corrosive flow but, as our technologies grow increasingly sophisticated, we find that lead may not be the best choice.
Issues with lead pipes center upon the electrochemical deposition of lead ions into the water. The corrosion of lead pipe is primarily due to electrical gradients between the lead pipe (or lead solder) and the acidic water.
Normal (potable) water has a neutral balance (it is neither acidic nor caustic)-once the water becomes acidic, lead will dissolve into the water.
In cases like the Flint River, excessive amounts of acids and metal salts from the auto industry have contributed to a corrosive watery environment.
In other areas, some of the salts and organics have slipped past sewer treatment facilities and wind up in our sources of drinking water. (These chemicals include sulfuric acid, Nickel, Iron, Manganese, Chromium, and other lesser known metals.)
The metals become salts-or dissolved metals in the water-there are little to no solid metal particulates. The resultant problem, dissolved metals in the water supply, puts children at risk—lead can stunt physical growth and significantly lower I.Q.s. It has also been found to harm the fetus, when pregnant women are exposed.
Correcting Lead Pipe Corrosion and Metal Leaching- Looking for Answers?
Addressing lead corrosion has a supposedly simple correction: Flush the lead pipes with a watery solution containing phosphate salts. The phosphates coat the lead pipes and inhibit corrosion. City engineers have applied the phosphate correction method since the 1970s, but not evenly throughout the US.
In the case of Flint, Michigan, water from the Flint river was not conditioned well enough with phosphates, and corrosion (and lead in the water) resulted.
News outlets portray the horrors of Flint, Michigan’s polluted water, and we are left wondering if it could happen elsewhere.
Well, the truth is that this does happen from time to time, but without publicity. Surveying most of the fresh water sources in Great Lakes region, one notices a disturbing finding-much of the water sources contain excessive amounts of chemical elements, Mercury (Hg), Lead (Pb), Chromium (Cr), Copper (Cu), Nickel (Ni), and organic chemicals. That region’s powerhouse economy-auto and steel-contributed to the present problems.
Water chemists and Civil Engineers have applied answers-one of them is the Lead-Copper rule. Introduced in the 1990s, but not widely adopted, the EPA sought to address instances where lead corrosion was endemic. The lead-copper rule sought to stabilize lead from corrosion by utilizing the properties of copper to change the water. The results have received mixed reviews, at best. Engineers have swapped sections of copper pipe for the lead pipe, but studies have shown only a moderate improvement in lead (Pb) levels.
One other solution was to aerate the water prior to its release to consumers. Aeration involves subjecting water to volumes of ‘air’ -the process allows any dissolved gases to be purged from the water. Gases such as Carbon Dioxide affect the leaching of lead from the pipes at the consumer end of water usage. Although the process shows promise for water districts that use older-type lead piping-it is subject to inconsistencies that still arise at the customer end of water usage.
What can be said in no uncertain terms is this — water purification followed with lead pipes on the customer end is more of an art than a science.
Properties of Water: Finding Answers…
When you observe a glass of clean water, it will seek to ‘bead upon itself,’ in part, because the molecules seek to form stable structures-or self-adhere. The water seeks the least amount of volume.
The self-adherence, sticking to itself, is also termed Hydrogen bonding. The hydrogen bonding in the water molecule enables water to corrode metal-it can be rust (iron oxide) or lead oxide or nickel oxide, as well. Although this seemingly simple property occurs with – or without – any human intervention, it presents a better (and costlier) solution for lead poisoning problem:
Remove the majority of lead (Pb) and other metal piping used for water intake and sewer out take. That action (alone) would assure the removal of toxic metals from most consumers’ faucets.
Composite materials and polyvinyl chloride (PVC) have become ‘the go-to’ replacements in new housing construction. In many instances, composites are superior to the lead (Pb). The major stumbling block is economic, as replacing vast quantities of pipe appears to be cost-prohibitive.
However, mounting a large infrastructure improvement project has been spoken of since the 1980s. And, there is no time like the present… So, let us recall the ancient Romans, who foolishly used lead (Pb) as a sweetener in wine production, and be wiser than the Romans. Let’s hope all roads don’t lead to Rome.
Decoding Science. One article at a time.