Septic & Trenching
Services

In both Sonoma and Monterey counties, new septic system installation requires a permit from the county Environmental Health department. The process typically involves a site evaluation (including a percolation test or soil morphology review), a system design review, permit issuance, installation, and a final inspection before the system can be placed into service. Some municipalities within these counties also require a separate building or plumbing permit. The timeline from application to permit can range from a few weeks to several months depending on the county's workload and the complexity of the site. We've been through this process many times across the California Central Coast and can help you understand what to expect for your specific parcel.

The physical installation — once permits are in hand — typically takes two to five days for a standard residential system. That includes excavation, tank placement, leach field installation, backfill, and surface restoration. More complex systems (alternative designs, mound systems, large-capacity systems for agricultural use) take longer. The permit process is usually the longest part of the timeline. For planning purposes, count on at least six to twelve weeks from when you initiate the permit process to when installation can begin, though this varies significantly by county and season.

Trench depth depends on the utility type and applicable code requirements. Water service lines in California are typically installed at 18 to 24 inches minimum depth for frost protection, though in Central Coast climates where freezing is not a significant concern, local inspectors sometimes accept shallower installations. Sewer laterals are typically installed at the depth required to achieve proper slope to the connection point — this can vary considerably. Electrical conduit depth depends on whether it's direct burial cable or conduit, and whether it's under a paved surface. We assess each project and trench to the depth required by the specific utility and applicable codes.

Joint trenching places multiple utilities — water, power, telecommunications, gas — in a single trench rather than separate trenches for each. When local codes and utility company requirements allow it, this approach reduces total site disturbance, cuts the cost of excavation and surface restoration, and shortens the project timeline. It requires careful coordination between utility types (separation distances, bedding requirements, and inspection timing all need to align), but for new development projects or major property infrastructure upgrades, it's often the most efficient approach. We'll advise you on whether joint trenching is feasible for your specific project scope and location.

Common signs that a septic system is failing include: slow drains throughout the house (not just one fixture), sewage odors inside or outside the home, wet or unusually lush areas over the leach field, sewage surfacing in the yard, or a backup through floor drains or the lowest fixture in the home. Some failures are gradual and don't produce dramatic symptoms until the system is significantly compromised. If your system is more than 25 to 30 years old, hasn't been pumped regularly, or was originally installed on a property that's seen increased occupancy or water use, a professional assessment is a reasonable precaution. We can evaluate existing systems and give you an honest assessment of whether repair or replacement is the right call.

California's Underground Service Alert (USA North 811) is the mandatory utility locate service that must be notified before any excavation. When you call 811 or submit an online request, the relevant utility companies send locators to mark the approximate location of their underground infrastructure with paint or flags. This process is legally required and must be completed at least two working days before excavation begins. Hitting an unmarked or mislocated utility line causes delays, repair costs, potential service outages for neighbors, and in the case of gas or electrical lines, serious safety hazards. We handle the 811 locate process on every project as a standard part of pre-construction coordination.

Yes — surface reclamation is a standard part of every trenching project we do. Depending on what was there before excavation, restoration might involve backfill and compaction to prevent settling, reseeding disturbed turf areas, replacing gravel or aggregate surfaces, re-establishing drainage patterns, or preparing a surface for paving or other finish work. We aim to leave the site in the same condition it was in before we started — or better. If the existing surface was already in poor condition, this is a good opportunity to address that as part of the overall scope.

Yes. Agricultural properties across the California Central Coast — particularly in the Salinas Valley, Sonoma County wine country, and other farming areas — often need irrigation mainlines, water supply systems, and waste connections running long distances across the property. We have experience with the scale and scope of agricultural trenching, including long service runs, deep installation depths for agricultural water lines, and coordination with irrigation system designers and water district requirements. If you have a specific agricultural infrastructure project, call us at (707) 601-9091 to discuss the scope.

Call us at (707) 601-9091 or use the contact form on this page. For septic projects, we'll need to know the property address, the intended use (residential, agricultural, commercial), whether there's an existing system, and where you are in the permit process. For utility trenching, we need to know the utility types, approximate run lengths, and what's on the surface above the trench path. A site visit is the most reliable way to give you an accurate estimate — remote quoting is possible for a rough ballpark, but below-grade work has too many site-specific variables to price accurately without seeing the ground.

We serve Sonoma County, Monterey County, and the broader California Central Coast, including Santa Cruz County, San Benito County, and Santa Clara County. Our primary service areas are the Sonoma County wine country and greater Santa Rosa area in the north, and Monterey County including the Salinas Valley, Carmel Valley, and coastal communities in the south. If you're unsure whether we serve your area, call us and we'll let you know directly.