Where Does Your Water Go?

Where Does Your Water Go?

This is a story about water—

the element that makes up more than most of our body mass and probably seems, to a lot of people, a readily-accessible, never-ending source of life. To those lucky enough to have constant access to water, it can easily be taken for granted. But where your water comes from is quite a process—and where it goes after it leaves your drain is another.

We spoke with Vic Bernsdorff, former Wastewater Treatment Plant Operator at the Municipal Utilities Department for the city of Stockton, California. With his help, we broke down municipal water processes so you can get an idea of where the water that comes out of your sink comes from, and where it goes when it leaves your home—along with everything else that goes down your drain.


Water treatment is a complex process and though there’s much more to this story than we can fit into this post, we’re attempting to simplify the subject matter in order to better understand local water lifecycles.

Since there’s a lot to tell, we’ll be covering this topic in two parts. Both are important, but we’d like to start our story with laundry and what happens after you do it. Have you ever thought about what happens to your detergent after you wash your clothes?

So where does your water go?

All household wastewater (from toilets, sinks, and laundry water) is collected in a city’s “sanitary sewer” system. The toilet, sink and laundry water from both households and businesses is then pumped through wastewater collection systems and then to a wastewater plant for processing.

When the wastewater reaches the treatment plant, a handful of processes take over to separate the sediment and sludge and then clean the wastewater. After completing the last two treatment processes (chlorination and subsequent de-chlorination), the water is no longer considered wastewater.



At the final stage of treatment, a water sampler and various sensors test the water against very tight permit discharge regulations held by the National Pollutant Discharge Elimination System (NPDES). The water quality standards and regulations that are mandated by the NPDES ensure that treated water is safe enough to discharge. If the treated water meets all NPDES permit requirements, it is then discharged into waterways.
After treatment plant water is discharged into waterways, the combined water (river water and plant effluent*) is then used as intake water to a potable water treatment plant (potable just means safe for drinking). In Stockton for example, the San Joaquin River is used to prepare and distribute 30 million gallons of potable water per day for their citizens and the surrounding metro area. Ground water sources, if needed, are used to make up any difference in demand.
*effluent water is waste material which is discharged into sewers from any industrial or business processes. This is different from daily household waste products and can be defined as anything other than daily waste products like toilets, baths or other waste.

Drains are not trash bins.

F.O.G. (Fats, Oils, & Grease) need to be kept out of the drain. Things like bacon grease, butter, frying oil, etc. Those items will harden, build up in size, and soon restrict the wastewater flow to the treatment plant – causing sewage back-ups. They should be drained into empty cans, left to harden and then thrown out. In addition, garbage disposals were not designed to shred all types of foods so it's best to use the kitchen garbage disposal sparingly and only with food scraps it was designed for. 
There is also the common practice (and problem) of residents disposing of their pharmaceuticals in the toilet. Wastewater treatment plants were never designed to remove drugs out of the wastewater steam. So, when someone disposes of them by dumping them down the toilet, they go right through the wastewater plant and enter the waterways. Once there, fish and other aquatic life will ingest them and become sick, die, or even develop deformities. 
Anything that obstructs the flow of sewage to the treatment plant is problematic. If residents keep using wastewater collection systems as trash bins, sewage backups will become more frequent and result in costs for removal and higher monthly services rates. 

12 items you should never put down your toilet…

A quick note – never violate the four “P”s (Toilet Paper, Pee, Poop & Puke….gross we know, but pertinent). Ok now for your toilet no no items:

01. Tissues and paper towels
02. Cat litter
03. Disposable diapers and tampons
04. Condoms
05. Anything made of cotton or plastic
06. Dental floss
07. Undigested food (puck is ok)
08. Gum
09. Hair
10. Pills
11. Grease and oils
12. Products claiming to be 'flushable'

How much does where you live affect this process?

In general terms, as far as processes are concerned, the potable water treatment and wastewater treatment facilities pretty much use variations of the same standard processes - regardless of where one lives. However, the further one’s home is from a city, the more likely it is that the homeowners will be using private well water instead of treatment plant water for drinking, and using a private septic system combined with a leach field to dispose of their household wastewater.

Is wastewater wasteful?

The wastewater process is always going through upgrades based on new environmental regulations and as needed to adapt to changes in the water cycle. For example, in Orange County, California they have built a stand-alone “toilet-to-tap” facility that does exactly what the term implies in order to help conserve water due to California’s persistent drought problems. Because of lack of sufficient rain during past winter months in California, these types of plants will most certainly become the standard in the near future if droughts continue.

Anything you *should* put down your drain (besides water)?

Pouring half a bottle of hot vinegar down the kitchen sink drain every three months followed by a flush of very hot faucet water will keep food scraps from sticking to the pipes and causing obstructions. For even better results, some plumbers suggest pouring a ½ cup of baking soda down the drain first before applying the hot vinegar. Disclosure: Put on protective glasses first though if using the baking soda!

Read more

Ask Dr. Pete: What are Optical Brighteners and Why Should We Care?

Ask Dr. Pete: What are Optical Brighteners and Why Should We Care?

Plastic-free and the road to a sustainable future.

Plastic-free and the road to a sustainable future.

Where Does Your Water Come From?

Where Does Your Water Come From?