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Municipal Water Explainer

Municipal water’s dirty little secret.

If you live in the U.S., there is a good chance that your tap water is coming from a municipal or community water system. We take for granted that the water flowing from our taps is clean, but how do municipal water systems work and are they effective at delivering pure, safe water to our homes?

How municipal water systems work

In municipal water systems, water is withdrawn from the water source such as rivers, lakes, and aquifers, and treated before it gets pumped to your home. The treatment typically includes some combination of these steps:

1. Coagulation and Flocculation
Here, chemicals with a positive charge are added to the water in order to neutralize the negative charge of dissolved particles in the water. When this occurs, the particles bind with the chemicals and form larger particles.
2. Sedimentation
During sedimentation, the larger particles settle to the bottom of the water supply, due to their weight. The clear water on top passes through to the next step in the process called filtration.
3. Filtration
At this stage, water passes through various types of filters such as gravel and charcoal in order to remove dissolved particles still present.
4. Disinfection
In the final step, a disinfectant, usually chlorine, is added to the water to kill parasites, bacteria, and viruses, and to protect the water from germs as it makes its way to your home.

Municipal water’s dirty little secret

Chlorine disinfection by municipal water systems is not without its complications or risks.
Firstly, it is ineffective on turbid water. Turbidity refers to the presence of fine suspended particles of clay, silt, organic and inorganic matter, and microscopic pathogens—particles not removed in the earlier stages of the water treatment process. 
Bacteria, viruses, and parasites such as Giardia and Cryptosporidium can attach themselves to the suspended particles in turbid water, which then impedes the treatment process by shielding the contaminants from the chemical disinfectant. To overcome this challenge, water utilities need to use even larger amounts of disinfectants to do the job. This can then lead to the presence of carcinogenic disinfection byproducts (DBPs) in the water.
Known as THMs (short for trihalomethanes), these carcinogens are created when chlorine reacts with the organic matter present in water. The amount of THMs in your drinking water depends on factors such as the time of year and the source of the water. For instance, THMs are higher when rivers or other surface waters are the source because the water tends to be more turbid, with higher volumes of organic matter. Primary sources of DBPs in the U.S. are chlorinated drinking water. Common DBPs include the chemicals chloroform, haloacetic acids, haloacetonitriles, haloketones, and chlorophenols. According to the Environmental Working Group (EWG.org), health concerns for THMs include bladder cancer, skin cancer, and fetal growth and development.  

Does chlorine treatment remove pathogens?

Another troubling aspect of municipal water treatment through chlorine disinfection is that it doesn’t necessarily do the job! Pathogens such as parasites and spores are often chlorine resistant, and chlorine does nothing for other contaminants such as trace pharmaceuticals and endocrine disruptors.

Effective chemical- and byproduct-free filtration 

Seccua’s state-of-the-art ultrafiltration process is a chemical- and byproduct-free complement to municipal water treatment.
Our patented membrane eliminates turbidity and up to 99.99% of all viruses, bacteria, parasites and cysts without any byproducts or chemical residues. And rather than simply killing or inactivating the microorganisms in the water, ultrafiltration actually removes them, keeping the potential for subsequent contamination or biofilm buildup low.