Sourced from Central Contra Costa Sanitary District published Septic to Sewer program material, and USDA and RCAC program documentation — last checked August 2026.
What Central San Will Finance
Most California counties offer a homeowner nothing at all for septic work. Contra Costa is the exception, because Central San — the Central Contra Costa Sanitary District — wants septic properties on its sewer and is willing to lend to make that happen.
The terms it publishes:
- Loan of up to $65,000
- 5.82% interest
- 15-year term
- Repaid in annual installments via the Contra Costa County Property Tax Roll
- “No penalty for early pay-off”
Eligibility, in the district’s words, is “residential property owners with private septic systems located near existing sewer mains.”
What the Money Covers
This is where the program is unusually complete. It is not just the pipe.
- Lateral construction
- “Septic abandonment costs”
- CAD, AVAD and reimbursement fees
- “All Central San fees, including capacity fees, application fees, and inspection fees”
Capacity fees are the item people miss when they budget a sewer connection themselves. They are frequently the largest single line, and they are inside this loan.
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Repayment Through the Tax Roll Is the Interesting Part
Most home improvement borrowing is a personal debt with a monthly payment and a credit check. This is collected annually on your property tax bill instead.
That has practical consequences worth thinking through. It is one payment a year rather than twelve, which suits some households and not others. It is attached to the property, so if you are likely to sell inside fifteen years, ask specifically how the remaining balance is handled at transfer. And because there is no early payoff penalty, you can clear it whenever it suits you.
How This Compares
Against the statewide routes, Central San is in a different league on size, and a different league on cost.
- USDA Section 504: up to $40,000 at 1% over 20 years, but only in USDA-eligible rural areas and only below a very-low-income limit. Far cheaper money, far narrower gate.
- RCAC: up to $15,000 at 1%, communities of 50,000 or fewer.
- Central San: up to $65,000 at 5.82%, no income test published, but only for connecting to sewer — not for repairing or replacing a septic system you intend to keep.
That last point is the one to be clear about. This is money for leaving septic behind, not for fixing it. If you want to stay on septic, this program is not for you and the statewide routes on our California septic assistance page are.
Who to Call
Central Contra Costa Sanitary District administers the program, sets the rate and confirms whether your property counts as near an existing main. That last question is the one that decides eligibility, and it is not something to judge from a map.
If your Contra Costa property is outside Central San’s service area, ask whichever district operates your local sewer whether it runs anything equivalent. Programs of this kind are almost never advertised outside the district that funds them, which is exactly why so few homeowners know they exist.
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Frequently Asked Questions
How much can I borrow from Central San to connect to sewer?
Up to $65,000 at 5.82% over a 15-year term, repaid in annual installments through the Contra Costa County property tax roll, with no penalty for early pay-off. Eligibility is residential property owners with private septic systems located near existing sewer mains. Confirm the current rate before applying — the 5.82% figure comes from a flyer coded 6/24 and the district footnotes it as anticipated to change on July 1, 2027.
What does the Central San loan actually cover?
More than most people expect. Lateral construction, septic abandonment costs, CAD, AVAD and reimbursement fees, and in the district’s words "All Central San fees, including capacity fees, application fees, and inspection fees." Capacity fees are the item homeowners most often leave out when budgeting a connection themselves, and they are frequently the largest single line. They are inside this loan.
Can I use Central San financing to repair my septic system?
No. This is money for connecting to the sewer, not for repairing or replacing a septic system you intend to keep. If you want to stay on septic, the routes available to you are the statewide ones — USDA Section 504 at up to $40,000 and 1% for USDA-eligible rural areas below a very-low-income limit, and RCAC at up to $15,000 and 1% for communities of 50,000 or fewer.
What happens to the loan if I sell the house?
The loan is repaid through the property tax roll, which means it is attached to the property rather than collected as a personal monthly debt. If you expect to sell within the fifteen-year term, ask Central San specifically how the outstanding balance is handled at transfer before you commit. Because there is no early pay-off penalty, clearing it at sale is an option.