Frequently Asked Questions

What do ​I do if I'm having sewer stoppage or backup?
Call the Maintenance Services Department at (650) 947-2785. For after hours calls, dial the Los Altos Police Department at (650) 947-2770 and Maintenance personnel will be dispatched. Standby personnel are available for emergency response on a 24-hour basis.

Maintenance personnel will check the main sewer line for any blockage and clear it if necessary. If there is a cleanout at the property line, they will also inspect to determine if the stoppage is in the lateral line between the cleanout and the main line. Crews will clear the stoppage as a courtesy if the blockage is between the property line cleanout (if accessible) and the main sewer line. Residents will be notified if the stoppage is a private plumbing problem. 

What is​ the property owner's responsibility regarding the sewer lateral?
The property owner is responsible for cleaning and maintaining the street and house lateral all the way to the main sewer, except for reconstruction and repair. The City is not responsible for any plumbing bills except when a street lateral requires reconstruction or repair. (Municipal Code 10.04.290 - Maintenance of sewer laterals)

Defective street lateral line – If the private contractor is unable to clear a stoppage due to a defect in the sewer lateral, the City will repair it if the defect is beyond the first full section of pipe past the cleanout. Otherwise, the property owner is responsible for repairs to the lateral. Please see the Sewer Lateral Responsibilities Diagram for more information.

What if you see water coming out of a manhole or cleanout?
Turn off any water that you may have running and contact the Maintenance Department. A manhole cover is 27” diameter and usually located in the street (sometimes there are manholes in backyards). It is made from cast iron and weighs 220 lbs. A sewer cleanout is 9” diameter and usually has a concrete cover over a plastic cleanout cap. These are usually located at your property line.

Can I drain storm water into the sewers?
No. Sewer pipes are only for wastewater. Adding storm water will exceed the capacity of the sewer pipe. It is a violation of the Municipal Code, as is discharging any hazardous material, pesticides, oil-based paint, large amounts of latex paint, or photo developing chemicals into the sewer system. Water drained from swimming pools or spas must be drained into your private sewer system at a rate of no more than 100 gallons per minute or onto private property landscaping. This water is prohibited from being drained into the street area and storm drains. Violations may result in a citation and fine.

What can I do about sewer smells?
Contact the Maintenance Services Department, as this could indicate a partial sewer blockage. If you don’t know the location of your sewer lateral, contact the City of Los Altos Engineering Services Division at (650) 947-2780.


  • Know where your sewer cleanout at the property line is and keep it accessible and keep the cleanout cap hand tight.
  • If you have a sewer manhole in your backyard, make sure it is kept accessible.
  • If you do not have a property line cleanout, consider installing one.