When you pull the drain plug, wash clothes, or flush the toilet the magic of wastewater begins......

The clean water that comes into your house by one set of pipes, must leave your house by another set of pipes. When you live in the City the wastewater that leaves your home is carried by a pipe to the City’s sewer pipes that are buried underground. Usually when you see streets dug up for work on a pipe line, it is either the sewer pipes or the pipes that bring drinking water to your home. When you live in the country, wastewater goes into large underground tanks called septic tanks.

The sewer pipes empty into larger pipes, called trunk lines. The City of Pueblo has six major trunk lines that merge to bring all the wastewater to plant for treatment.

The first thing we do to start cleaning the wastewater is to run it through big screens. These screens catch the rags, diapers, rocks, pieces of wood and other large items. A rake pulls the trash off the screen and dumps it on a moving belt that carries the trash to the truck that takes it to the dump. Gravel, seeds, and other heavy particles are then removed from the wastewater by a grit chamber that spins the water in circles, allowing the heavy particles to fall to the bottom.

The wastewater then enters into the Primary Clarifiers, which are large tanks where the water sits quietly. The heavy solids that are remaining settle to the bottom and the lighter things like grease float to the top. The heavy solids and the grease are taken to the digester to be treated. We will talk about them more later. The water coming off in between these layers is still dirty because it contains stuff dissolved in the water. It is ready to go onto the next process to be cleaned more.

At this point we have done what we can to clean the water and now we have to get help. The wastewater is carried to the top of many layers of thin plastic webs in a tank called a trickling filter. As the water flows through these webs, the webs get covered with a slime of bacteria, protozoa and fungi, just like the slick rocks you walk on in a stream. The bacteria and fungi use the dissolved organics, in the wastewater for food and the protozoa feed on the bacteria.

Pipes then carry the wastewater to the Aeration Basin. This is a large tank with a lot of bacteria and protozoa in it. These bugs need to have oxygen bubbled into the water to grow quickly. By eating the dissolved materials as their food the bacteria grow and increase in number until they can be separated from the wastewater.

The wastewater is piped to other tanks called Secondary Clarifiers that let the bacteria settle to the bottom, and they are taken to the digester also. The nearly clean water that comes off the top is piped to the next step.

Chlorine is used to kill any bacteria that are left in the water before it goes back into the river. Since chlorine can kill the fish, we have to remove the chlorine with another chemical called sulfur dioxide after the bacteria are dead.

Now the water is clean and can be put into the river. In some areas the water needs to be cleaner to keep the unwanted plants and algae from growing so much that there isn’t any oxygen left for the fish. If this is a problem then the wastewater plant would also be required to remove nitrogen and phosphorus before taking it back to the river. These nutrients are good in small amounts since they are the same as the fertilizer you put on your grass, but too much can cause problems.

Now are we done? The river is getting clean water and…….

Oops…. what about the heavy stuff from the bottom of all of the tanks? This is called sludge. The sludge is piped to a large tank called a digester where it is heated to almost 100 degrees. The solids in the tank are turned into gas and harmless sludge by a different type of bacteria. The gas is burned in a boiler to provide heat for all the buildings at the Water Reclamation Facility. After the sludge has been in the digesters about 30 days it is dried. The treated sludge, now called Biosolids, looks almost like dirt. The Biosolids can be put into a landfill or used as a fertilizer to improve the soil.

As you can see, our job is really to just make the bacteria happy so that they will do most of the work to clean the wastewater for us. We have to keep all the equipment working to give them what they need and to move the wastewater and sludge to the next step.

Wastewater treatment goes on every day and every night. It is very important to the quality of the water in our rivers, but everything will stop getting clean if the bacteria die. Dirty water can carry many diseases that can cause illnesses that we do not typically see in the United States because of how we clean the water.

That is why it is important not to put any chemicals down the drain in your home. We do not want to kill the bacteria and let dirty water get into our river. Remember the water we have now is all the water we've ever had, and all the water we will ever have.

ONLY YOU CAN PREVENT WATER POLLUTION Remember: We all live downstream! We have a responsibility to clean up our wastewater to protect the river for everyone.