Permit and Resource Management Department Banner

Frequently Asked Questions About Sewers

Sewer Inspection

When do I need my first sewer inspection?

Your first inspection is required when trench digging is complete. We must see the bottom of the trench. This is called a trench inspection.

Why are so many sewer inspections required?

Sewer inspections during the construction phase assure a quality connection. This protects the treatment plant from storm water infiltration. It also protects your property from sewage leaks.

Why must I give 48 hour notice for a sewer inspection?

We schedule multiple inspections throughout the county every day. Because Sonoma County is so large, we try to schedule inspections for projects that are located near each other on the same day. With 48 hours notice we are able to inspect much more efficiently.

My existing sewer pipes have worked fine for years. Why can't I keep using them?

Although they may seem to be working, older systems are seldom tightly sealed. This can allow storm water to enter the system which will cause problems at the treatment plant.

Why can I use rubber couplings (Calder or Fernco couplings) for connecting my sewer pipes?

This type of connection is typically used for joining unlike pipes, such as iron pipe to plastic pipe.

Why do I have to dig such a deep trench to connect my house to sewer?

The depth of cover required for plastic pipe is a minimum of 24 inches. This depth helps to protect the pipe from damage. If you are using iron pipe the minimum cover depth is 18 inches.

Why am I required to install a backflow preventer? My neighbor didn't have to do this.

The purpose of the backflow preventer is to stop sewage from backing up in your home in the event that the main sewer line becomes blocked. Each sewer connection is unique. Your house may be at a slightly lower elevation than that of your neighbor.

What type of material do I use for backfilling the trench?

This varies from one project to another. You must use #4 rock (pea gravel with fines) or other materials approved by PRMD.

Do I have to hire a licensed contractor to connect my sewer?

A licensed contractor is required for any work in a public right of way. On private property, we recommend the use of a licensed contractor if the trench depth is over 5' or if a grease trap or monitoring manhole is required.

Sewer Districts

Is my property in a sewer district? -or- Is my property hooked to sewer?

Sewer/Sanitation District

To find out if your property is within a sewer/sanitation district, use our Parcel Report tool to look up by Assessor's Parcel Number (APN) or street address. It contains important information about your parcel including sanitation district. Look for "Sanitation District" in the search results. If your property is within a sanitation district, the name of the district is displayed. If your property is not within a sanitation district, "Not Applicable" is displayed.

Hooked to Sewer

If you are within a sanitation district, you can confirm if your property is hooked to the sewer by calling us at (707) 565-2268 during regular phone hours and ask to speak with staff in the Sanitation Section. Please have your Assessor's Parcel Number (APN) available. This number can be found on your annual property tax bill or by searching for your street address via the Parcel Report. If you don't have a tax bill available or access to the online link we can locate the property if you provide us with the street address and the owner's name.

How can my property be served by sewer?

First you should determine whether your property is within a sewer district. If your property is not within a sewer district you must obtain an Outside Service Agreement. If your property is within a sewer district there are several factors involved, including;

  • If there is a mainline nearby.
  • If there is a lateral from this mainline to your property.

A "No" answer to either of these questions triggers the need for a plan check, which could be a simple review of a hand drawn site plan, or a thorough review of engineered plans.

In addition, the following questions must be answered;

Is there a gravity flow to the mainline? If not, you will need a pumping system.

If there is an existing septic tank, it must be destroyed. This requires a Septic Tank Destruction Permit from Permit Sonoma's Well and Septic Section.

What permits do I need to connect a single family residence to public sewer?

Under normal circumstances you will need a sewer permit and an encroachment permit. Fees will be charged per the current fee schedule.

Does the sewer district or the County install my sewer line?

No. Installation is your responsibility.

Who pays for connecting my property to sewer?

It is your responsibility to pay for all permits, sewer work, inspection fees, connection fees and service charges.

Do I have to hire a licensed contractor to connect my sewer?

A licensed, bonded contractor with current insurance is required for any work in a public right of way. We recommend the use of a licensed contractor if the trench depth is over 5' or if a grease trap or monitoring manhole is required.

Contact Information

Contact Us by Phone
2550 Ventura Avenue
Santa Rosa, CA 95403
38.465074, -122.723705

Sanitation Codes & Standards

Sanitation Codes and Standards
Codes set forth uniform requirements for contributors to the wastewater collection and treatment systems.