The Tier 1 numbers a new or replacement field starts from
Tier 1 applies where no local program is approved. For a new or replacement low-risk system it caps design flow at 3,500 gallons per day and sets setbacks of 5 feet from property lines and structures and 100 feet from water wells. The well setback is the larger one. A system stays in Tier 1 while it meets those requirements, so measure to your well and the lot line before the first site visit.
Drain field costs in California: repair and full replacement
Our model puts a field repair at $1,200 to $8,150 per repair and gives full replacement its own row, and both are estimates, not quotes. One national range per row, scaled by the California operating engineer wage ratio, sets them, with no California company sample behind either.
| Item | Figure | What it is |
|---|---|---|
| Estimated range, not a quote | $1,200 to $8,150 per repair | Built from one national published range, adjusted by the California operating engineer wage ratio (1.42). Seven California companies publish a septic pumping price or typical range (only two print a firm $450) and one a $350 inspection; the pumping range is the middle half of those pumping prices, and a single inspection price is too few to move that estimate. Installation prices from three companies (from $5,000 in the Central Valley to $20,000 or more in the Sierra foothills) are recorded in the price file and not used. Basis: no state company sample (no counted California company price for this job), national estimate only. |
| Estimated range for a full drain field replacement, not a quote | $3,625 to $24,500 per replacement | Built from one national published range, adjusted by the California operating engineer wage ratio (1.42). Seven California companies publish a septic pumping price or typical range (only two print a firm $450) and one a $350 inspection; the pumping range is the middle half of those pumping prices, and a single inspection price is too few to move that estimate. Installation prices from three companies (from $5,000 in the Central Valley to $20,000 or more in the Sierra foothills) are recorded in the price file and not used. Basis: no state company sample (no counted California company price for this job), national estimate only. |
Estimated range. Built from national published ranges (1 source), adjusted by California's operating engineer wage ratio to the US (1.42, BLS May 2025). Not a quote. Seven California companies publish a septic pumping price or typical range (only two print a firm $450) and one a $350 inspection; the pumping range is the middle half of those pumping prices, and a single inspection price is too few to move that estimate. Installation prices from three companies (from $5,000 in the Central Valley to $20,000 or more in the Sierra foothills) are recorded in the price file and not used. We have no counted California company price for this job, so the range is our national estimate alone. Full method. Prices as of Oct 23, 2026.
When a county program or impaired water changes the numbers
An approved Local Agency Management Program supersedes Tier 1 for that agency until it's modified, withdrawn or revoked. Then check the 600-foot line. A new or replacement system within 600 feet of an impaired water body on the policy's Attachment 2 must meet Tier 3, unless a TMDL or the program's special provisions say otherwise. Ask the county's environmental health office which tier your address falls under.
The 811 call before the excavator arrives
Under Government Code 4216.2, whoever digs out the old field must call the regional notification center between two working days and 14 calendar days ahead, not counting the day of the call. Ask the company who calls and on what day.
Field problems that need a call today
- Sewage is surfacing over the field or backing up into the house.
- A slow drain with dry ground over the field.
Before anyone digs up the yard
- Mark where the ground is wet or soft, and note when it started.
- Ask the environmental health office which tier applies to your address.
- Ask the company who will notify 811, and on what date.
Permits when the field is repaired or replaced
Ask the county's environmental health office what its program needs for a field repair or replacement, and whether it treats your job as a major repair under Tier 4. Bring the well and property-line distances to that conversation.
Questions people ask
How close can a septic field be to a well in California?
That's the Tier 1 setback for new or replacement low-risk systems, along with 5 feet from property lines and structures. An approved county program supersedes Tier 1, so confirm the distance with the local agency.
Can a failing drain field be repaired, or must it be replaced?
Once the system is failing it sits in Tier 4, where a major repair has to meet the Tier 1 or Tier 2 standards in effect locally. The agency's answer tells you which standards the work has to meet.
What does a drain field repair cost in California?
Full replacement has its own, higher row in the cost table, and neither includes the county's permit fee.
Who calls 811 before a septic dig in California?
Government Code 4216.2 puts the notice on the excavator, no earlier than 14 calendar days before the dig. Confirm the date with the company.
- OWTS Policy sections 7-8 Read Oct 20, 2026.
- Government Code 4216.2 Read Oct 20, 2026.
- U.S. Bureau of Labor Statistics, OEWS May 2025: Operating Engineers and Other Construction Equipment Operators (SOC 47-2073), California, mean hourly wage Read Oct 23, 2026.
- U.S. Bureau of Labor Statistics, OEWS May 2025: Operating Engineers and Other Construction Equipment Operators (SOC 47-2073), United States, mean hourly wage Read Oct 23, 2026.
- SepticMatch: how we estimate costs, California (editorial policy) Read Oct 23, 2026.