You don’t have to look very hard to find articles in the Wall Street Journal, Fast Company or on various websites over the past few months to find columns on the issue of water quality. Since water is one of our most basic resources, it stands to reason that it would be a news topic.
What you don’t find are a lot of columns or blogs answering the question of “How do I get my water?” We have received lots of feedback from our Fans about this, so we wanted to take this opportunity to run through common municipal water treatment processes.
First you have to start with a water source. We love to talk about snow in Colorado for all sorts of recreation each winter. Another reason snow is a big topic is that if you live in Denver, our primary water source is the runoff from snowmelt in the Rocky Mountains.
The municipal water treatment process consists of six steps:
1. Coagulation – raw water from reservoirs is drawn into mixing basins at a treatment plant. The treatment plant then adds alum, polymers and often times lime and carbon dioxide in order to cause small particles to stick to one another, forming larger particles.
2. Sedimentation – Over time, the larger particles become heavy enough to settle to the bottom of a basin. The sediment is then removed from the water.
3. Filtration – The water is then filtered through layers of fine, granulated materials – either sand or sand and coal, depending on the treatment plant. As smaller, suspended solids are removed, turbidity diminishes and clear water emerges.
4. Disinfection – In order to protect against bacteria, viruses and other microbes that might remain, disinfectants (i.e. chlorine) are added before the water flows into underground reservoirs and the distribution system on its way to your home or business. Fluoride is also added to the treated water and some treatment plants use ultraviolet lights as well.
5. Corrosion Control – pH is maintained by adding alkaline substances to reduce corrosion in the distribution system and the plumbing in your home or business.
6. Testing – Occurs at the treatment plant and at various points along the distribution system.
Many parts of the world do not have access to potable water each day. We are very fortunate to live in a country that has developed an infrastructure so that we have access to this basic resource in our homes and businesses.
Up next – Since water is treated and tested at the municipal level, why does the water quality vary not only state to state, but also in different parts of the same city?