Sewer Disposal: What Can Go Down the Drain?

Questions? Contact Environment, Health and Safety

Overview

Find out what kinds of liquids can go down UC San Francisco drains. Whatever goes down the drain ends up in the ocean, so the SFPUC strictly regulates sewer waste.

What can go down the drain?

The only substances allowed down drains are those that meet all of the following criteria:

  1. Nonhazardous
    • No radioactive waste
    • No hazardous chemical waste
    • No untreated biohazardous waste
  2. Liquid
    • No solids, sludges, or viscous substances
  3. Will not interfere with sewage treatment operations
    • No corrosive pH levels
    • No grease or oil
    • No hot (125°F or higher) temperature

    OR

In the Chemicals Solutions List Approved for Drain Disposal (link to https://ehs.ucsf.edu/chemicals-approved-drain-disposal)

Click on a category below to find out if a substance is allowed to go down the drain.

Note: Protect drains from chemical spills — do not use sinks for chemical storage or secondary containment. Disposal of hazardous waste using sinks, intentional evaporation, intentional dilution or as regular trash is against the law. Campus laboratories must abide by strict state and federal waste disposal requirements. You may be held liable for violations of applicable laws.

Type of materials list on the left, and common drain disposal questions on the right.

Type of material: Common drain disposal questions:

Lists Materials and whether they can go down the drain, and what to do with it.

Material Can it go down the drain? What to do with it

Bio

hazardous waste

 Solids: NO

Liquids: NO, unless they have been deactivated

Liquid biohazardous waste can be decontaminated and made suitable for drain disposal:

  • Deactivate with bleach (1 part bleach to 9 parts liquid waste) for 30 minutes before pouring it down the drain.
  • Do not mix bleach with biological materials in trizol

Click here: For more information and for disposal instructions for solid biohazardous waste. (link to https://ehs.ucsf.edu/biohazardous-waste#Liquid-Biohazardous-Waste-Disposal)
Controlled substances NO Read Controlled Substances Waste Management (link to https://ehs.ucsf.edu/controlled-substances-waste-management ) for disposal procedures.
Radioactive waste NO Read Radioactive Waste (link to https://ehs.ucsf.edu/hazardous-waste ) for disposal instructions.
Hazardous chemical waste NO Read Chemical Waste (link to https://ehs.ucsf.edu/chemical-waste)  or guidance on hazardous chemical waste determination. Follow appropriate disposal procedures.
Non-liquids Can it go down the drain? What to do with it
Solids, sludges, or viscous substances NO These items can obstruct the flow of sewage.
Powders and salts NO

These items can obstruct the flow of sewage.

  • Do not dissolve them in water for disposal purposes.
Corrosive pH levels Can it go down the drain? What to do with it
Corrosive waste with a pH between 2.0 and 6.0 NO

Disposal method:
Corrosive waste with a pH of 2.0 or lower or pH of 12.5 or higher NO

This kind of waste is always considered hazardous chemical waste.
Hot liquids Can it go down the drain? What to do with it
Hot, nonhazardous liquids (125°F or more) NO
  • Cool the liquid or mix the hot water with abundant cold water to below 125°F before pouring it down the drain.
Grease and oil Can it go down the drain? What to do with it
Grease and oil NO, unless the concentration is less than 300 mg per liter

For higher concentrations:

  • Dispose of substances such as automotive oil, gear oil, and machinery grease as hazardous chemical waste.
  • Place substances such as vegetable oil, lard, or shortening in the regular trash.
Common questions Can it go down the drain? What to do with it
Alcohols NO

Disposal method:
Formalin and formaldehyde NO

Disposal method:
Hydrogen peroxide NO

Disposal method:
Photo and X-ray processor chemicals NO

Disposal method:
Other chemicals NO, unless it is on the list of Chemicals Solutions Approved for Drain Disposal

Otherwise:

Disposal method:
Latex paint NO

Disposal method:
Oil paint NO

Disposal method:
Wash and rinse water NO, unless it has not been contaminated by hazardous materials

Disposal method:
Power Washing of buildings or parking lots Not allowed without a permit and water sampling

Contact [email protected] to go over the permit process

Pre-treatment of soiled surfaces is required.
Dewatering of construction site ground water Not allowed without a permit and water sampling Contact [email protected] to go over the permit process.