Do you wonder where the water you use inside your home goes after a flush of the toilet or a rinse down the drain? It goes to the city’s Wastewater Treatment Plant, which just recently completed a large-scale renovation.

However, even a plant like ours needs help sometimes. Did you know that there are things that you can do in your home that can make a big difference down the pipes? By preventing pollutants from entering the city’s wastewater system, you can help preserve our environment by ensuring that treated wastewater leaving the treatment plant meets water quality requirements set by the Federal Clean Water Act.

Some pollutants (such as garbage, grease, fats and oils) can cause backups in sewer pipes and mechanical problems at the treatment plant when put into the sewer system. Other pollutants (such as heavy metals, chemicals and medications) can disrupt the biological processes at the wastewater treatment plant or pass through the treatment plant entirely (since traditional water treatment processes cannot remove them).

There are simple things everyone can do at home to help keep contaminants out of our water and to make sure everything flows smoothly. These tips include:

Dispose of hazardous waste properly

  • Please do not dispose of household chemicals in the sink or toilet. Residents can bring toxic items to the hazardous waste facility at the Yolo County Central Landfill for free every Friday and Saturday from 7:30 a.m. to 3:30 p.m.

Dispose of medicines properly

  • Unused medicines should never be poured down the sink or flushed down the toilet. Bring unwanted medications to the landfill hazardous waste facility or to the pharmaceutical collection bin at the Davis Police Department.

Don’t flush garbage (seriously)

  • Only human waste and toilet paper should be flushed down the toilet. Other products, sometimes even labeled as “flushable,” often do not break down enough to properly flow through sewer pipes, leading to clogged sewer lines and messy, expensive sewer backups. These products include “flushable” wipes, cat litter, hair, diapers, floss, feminine protection and other garbage. Once they reach the treatment plant, flushable wipes and other trash must be mechanically removed from wastewater before the wastewater can be treated.

No fats, oils or grease down the drain

  • Fats, oils, and grease can solidify after being poured down a drain or flushed down a toilet. This builds up and blocks the plumbing, leading to potential sewer backups in homes, onto streets and into local waterways. So how can you dispose of FOG? Small amounts of cool, hardened FOG can go in your organics cart. Larger amounts should go in a container and be placed in the trash or taken to the hazardous waste drop-off for free recycling.

Keep food waste out of the sink

  • The best place for food scraps is in the organics cart for composting, not in the sink. Sink drains, even sinks with garbage disposals, are not built to handle waste.

Scrape food off dishes into your organics pail or bin before washing them and consider using a drain screen in your sink to catch bits of food as you wash dishes. Remove the plastic labels on fruits and veggies, and place them in the trash. Plastic food labels on fruits and vegetables clog the filters at the wastewater treatment plant.

In addition to providing outreach and education for residents on ways to protect our wastewater system, the city’s Pre-Treatment Program inspects and monitors dental facilities, restaurants, breweries, groundwater remediation sites, laboratories and other commercial and industrial facilities that could potentially be discharging pollutants, such as salts, grease and heavy metals. These businesses are required to have alternative methods in place to keep these pollutants out of their wastewater or to remove them from their wastewater before it discharges to the city’s wastewater system. The city monitors these businesses to ensure that they are complying with regulations to prevent pollution.

We all do our part to keep the water flowing! For more information on the city’s Pre-Treatment Program or how to properly dispose of waste, please visit

Sandra Macomb is an Environmental Program Specialist for the city. Reach her at FOG image is courtesy City of Davis.

Crossposted from the Davis Enterprise

Published online  on June 11, 2019 | Printed in the June 12, 2019 edition on page A6