When you’re thirsty, you most likely fill a glass from the kitchen sink tap and don’t think twice about where it comes from or if it’s safe to drink. Drinking water in the United States is among the safest in the world, but our drinking water can still become contaminated by waterborne bacteria such as E. Coli or Hepatitis A. So why are most of us not getting sick from our drinking water?

In the US, rivers, lakes, and groundwater provide the source for our drinking water supplies, with the water flowing from intake points into a treatment plant and then to our houses. City water treatment is a crucial part of why we have safe, drinkable water in our homes. The water that comes out of your taps goes through a complex system of treatments to remove impurities, parasites, and bacteria before it arrives in your home as drinking water. Today, Optimum will be taking a look at exactly how cities across the US treat their drinking water.

Why Do We Need Water Treatment?

In the US, drinking water comes from one of two sources: surface water, such as streams, lakes, and rivers; or groundwater and underground sources that collect rain that has seeped through cracks and pores. These sources can easily become contaminated and require appropriate treatment before being dispersed to our homes.

Surface water is often contaminated by rainwater runoff that washes pesticides, nitrates, and trash into water sources as it trickles across roads and down hills. Groundwater usually becomes contaminated when the water that trickles through rocks picks up heavy metals such as arsenic.

Because of these methods of contamination, the Environmental Protection Agency has set legal limits for over 90 possible contaminants, meaning that drinking water has to meet these standards set by the EPA before it can be dispersed to homes. City water treatment processes are responsible for ensuring that drinking water meets those standards.

Standard Treatment Methods

While specific water treatment methods vary from city to city depending on the drinking water source, there are four standard treatment steps that all drinking water undergoes regardless of city specifics. These steps are coagulation and flocculation, sedimentation, filtration, and disinfection.

While all drinking water goes through these standard treatment steps, your water may go through different levels of treatment depending on where it’s sourced from. For example, surface water requires a higher level of coagulation and sedimentation as it is more likely to contain dirt and other contaminants than naturally filtered groundwater. In coagulation and flocculation, chemicals are added to the water that bind with dirt and other waterborne compounds to form larger particles called floc.

During the second step – sedimentation – because the floc is so heavy and dense, it settles at the bottom of the water supply, forming a removable layer of sludge. The sludge is composed of debris, viruses, and bacteria – all the stuff that needs to be removed from the water before it’s safe to drink.

Next up is filtration, a solid-liquid separation process. Once the floc has been removed from the supply, the remaining water is passed through filters composed of gravel, sand, or charcoal to remove any remaining particles such as dust, parasites, or toxic chemicals.

The final water treatment stage is disinfection in which a disinfectant (usually chlorine) is added to the water supply to kill any parasites, viruses, or bacteria that may not have been removed during the previous three steps. Disinfection not only removes any remaining particles, but it also protects the water from picking up any germs as it travels through pipes to homes and businesses.

City Specific Treatments

Depending on a variety of factors, your city may take additional steps to ensure your drinking water is properly treated before being piped into your home. For example, the Northeast and Midwest still use lead pipes to transport water around the city; the lead in these pipes can leach into the water supply if appropriate preventive measures are not implemented. According to the EPA, even low levels of lead poisoning can lead to stunted growth or behavioral issues. To prevent lead from leaching into the water supplies, water treatment in cities in the Northeast and Midwest involves adding phosphate to the water supply which forms a protective layer between the pipes and the water flowing through them.

In agricultural cities, nitrate runoff is a severe issue due to high levels of farming activity. The nitrate originates in fertilizers and septic systems and then is picked up by rain runoff. Nitrate poisoning can cause “blue-baby syndrome”, in which infants have difficulty breathing; the disease can be fatal. In these more agricultural areas where nitrate contamination is likely, city water treatment processes involve an ion exchange process to remove the nitrate.

Optimum Water Solutions

If you are concerned about the safety of your city’s drinking water, Optimum is here to help! Our bottleless water coolers employ a five-step filtration process to deliver the cleanest, safest drinking water. Our filtration methods remove toxins and other contaminants from your drinking water while also replenishing minerals and electrolytes. To find out more about our bottleless water coolers, visit our website today!