Lead & Other Heavy Metals
While national, state and local regulations have done a good job of ensuring that water leaves a municipal water treatment facility in safe conditions, the crumbling infrastructure between the facility and the tap can introduce distasteful and even dangerous contaminants.
The problems run deep and are more than a century old. As our cities were built, standard plumbing was made from lead. In fact, the word plumbing itself comes from the Latin word for lead, plumbum. As these pipes and joints age, they degrade and particulate lead flakes off. By 2020, experts estimate that the average American pipeline will be 45 years old. In fact, some have been in the ground for as many as 150 years.
Municipalities nationwide used lead service lines extensively from the late 1800s, peaking in the 1930s. At the same time, residential buildings also used lead piping. Over time, residential usage declined but did not stop until the EPA banned lead pipes as part of the Safe Drinking Water Act in 1976.
There are two types of lead found in water. One is relatively easy to remove. The other is vastly more complex:
1. Soluble lead, also known as 6.5 pH lead, typically comes from groundwater sources and can be removed through a chemical process that many filtration companies have mastered.
2. Particulate lead, or 8.5 pH lead, comes from environmental pollutants, such as paint and plumbing, and is much more challenging to remove. Very few filtration companies have certified products that can remove particulate lead at flow rates and capacity high enough for whole house (POE) applications.
Lead poisoning is particularly dangerous for children under age 6. Lead bioaccumulates in the body and even small amounts can cause serious health problems, such as severe mental and physical development, impaired cognition, behavioral disorders, hearing problems, and delayed puberty.
Some organizations estimate more than 300,000 children per year are diagnosed with unsafe levels of lead in their blood. Overall, the Center for Disease Control (CDC) estimates that 2.5% of small children have elevated levels.
The Environmental Protection Agency (EPA) estimates that there are approximately 98,000 public schools and 500,000 childcare facilities NOT regulated by the Safe Drinking Water Act (SDWA).
In Flint, Michigan’s case, the problem came when the city changed its water source from Lake Huron and Detroit River to the Flint River as part of a cost-savings initiative. The new water source had a higher pH and essentially stripped the insides of the lead pipes.
Other cities face similar problems when they switch from traditional chlorine to chloramines.
Thousands of cities across the country are challenged with aging infrastructure. Despite water leaving the treatment facility 100% safe, dangerous toxins can be introduced before the water reaches the consumer.
Public water utilities are responding to public health concerns around exposure to lead. Lead service lines are being replaced by many utilities, especially those utilities that are switching to chloramines as a disinfection agent. Chloramine tends to be more corrosive and likely to release particulate lead into the water supply.
The Center for Disease Control (CDC) estimates that at least 4 million households have children living in them being exposed to high levels of lead. More than half a million U.S. children under the age of 5 have blood lead levels above 5 micrograms per deciliter, the level at which the CDC recommends public health action, but no safe levels have been identified.
Municipalities are working on long-term solutions to replace lead pipes, but the process will take decades and as much as $300 billion.
Other Metals and Heavy Metals
Some lighter metals and metalloids are toxic and, thus, are termed heavy metals though some heavy metals, such as gold, typically are not toxic.
Although some metals meet certain criteria and not others, most would agree the elements mercury, bismuth, and lead are toxic metals with sufficiently high density.
Examples of heavy metals include lead, mercury, cadmium, arsenic, sometimes chromium.
Less commonly, metals including iron, copper, zinc, aluminum, beryllium, cobalt, and manganese may be considered heavy metals.
Why do Heavy Metals Exist in Drinking Water?
Environmental pollution with toxic heavy metals is spreading all over the globe along with industrial development.
The heavy metals are released into the environment through a natural process and anthropogenic activities. Industrial activities, especially electroplating, metal smelting, and chemical industries, and manufacturing processes.
Heavy metals can enter a water supply by industrial and consumer wastewater, or even from acidic rain breaking down soils and releasing heavy metals into streams, lakes, rivers, and groundwater.