ADU Sewer Connection

[David W.]

Orange County CA. I have an existing structure approx 14X12 we are considering converting to a ADU in 2020. The structure is 20' from the rear lot line. The building has gas, electrical sub panel, water but no sewer connection. Connecting a sewer line to the primary residence is problematic due to elevation and trenching into the house slab for 35', across a bedroom, hall and bath. It would also require a waste sump and pressurized line to move uphill.

The rear of the lot terminates onto the neighboring street, in the same development.  A new connection to the rear street is 20' and downhill but would require cutting the sidewalk and opening the street.  I just replaced a 50' sewer line on a rental in Texas, $6,500 including permit. The TX project did not require cutting into the city sidewalk or street. 

Back to Orange County CA, if the city will permit, what is the ballpark cost?  I have no idea if this is a 12k or 50k project in California.

[Chad New]

David, I just am closing on 3bd/2ba in Anaheim and plan to convert 640 sq ft detached garage into 2 bed apartment.  I have a rough quote to install sewer from Garage on left of photo to main sewer in crawl space.  I assume the money really depends on the distance and difficulty.  

[Pavan Sandhu]

@Chad New 100% on point distance and difficulty will determine cost

[David W.]

@Chad New Thanks for the details and good luck on your project.  Here is rear view of the lot with the building I want to expand to convert. Would need to trench down the hill and connect at the street.  Not sure if the city and utility will allow the creation of a new connection. I will find out next week. 

[Will Barnard]

You can not connect an ADU sewer line to the house sewer line, it must be direct to the street connection. Reason behind that is if the main house line gets backed up, you have now backed up your ADU as well and they do not allow that.

As to price to connect sewer line from street to ADU, it all depends on distance, size, scope of work, difficulty level, sewer connection fees, etc. I would advise getting a bid from 2-4 licensed plumbing contractors.

[John A Murray]

Originally posted by @Will Barnard:

You can not connect an ADU sewer line to the house sewer line, it must be direct to the street connection.

My neighbor hooked up his garage conversion ADU sewer line into his back sewer line just where it comes outside the homes foundation. At that point the two into one (Y connection) line goes 24' straight to the main; saving 24' of some deep digging.

[John A Murray]

Originally posted by @Chad New:

David, I just am closing on 3bd/2ba in Anaheim and plan to convert 640 sq ft detached garage into 2 bed apartment.  I have a rough quote to.

Chad if it were me I would get a few bids also. That's not a big or difficult job.

[Chad New]

Thanks for the sound advice John, the company that scoped the sewer on my home inspection gave the quote. I am working with a contractor with the ADU and will itemized all the work on the job. I will see what he prices that part of the job as well.

[Chad New]

Good news, the City of Anaheim stated there is no issues to add tie the ADU into city sewer. Now if I can just #1 - get some guidance on how to request a separate power meter and whip so it doesn't have to be sub-metered. #2 - get some guidance on how to properly set up my books on Quickbooks to start this endeavor correctly.

[John A Murray]

A neighbor down the street this year had the major radio-advertising plumber replace the two sewer lines (ficus tree roots) under her front yard. I was told she paid pushing $10,000 for a length of 39ft of sewer line. This company's two guys played around there all week.

Years ago my huge parkway ficus tree's roots invaded, cracking and plugging the two sewer lines in my front yard. I got two strong young guys at Home Depot on a Saturday morning and they dug them up; lines were about two feet deep where they came out under the foundation, and about shoulder deep at the sidewalk (city property line). My plumber friend replaced the old clay pipes with 45ft of ABS, installing clean-outs next to the house, and next day the guys filled the dirt back in. Total cost $1,100 plus $175 cash to scope. Not brain surgery just hard work.