Every home in Corte Madera sits on top of a pipe nobody sees until escrow makes them look. That pipe, the private sewer lateral, is what carries wastewater from the house to the public main under the street, and in this town it comes with a rule that catches sellers off guard more often than any roof or foundation item ever does.
The surprising part isn't that Corte Madera requires an inspection at the point of sale. Most sellers expect that much. The surprising part is who else the rule can pull in. If your lateral is shared with the house next door, listing your home doesn't just start your own clock. It starts theirs too, whether or not they have any plans to sell.
The District Line Doesn't Match the Map You Think You're Selling In
The agency behind this rule is Sanitary District No. 2 of Marin County, a subsidiary district to the Town of Corte Madera. Its service area covers the town itself, but it also extends into small portions of Larkspur and Tiburon, along with some adjacent unincorporated county land. A parcel marketed as "Corte Madera" isn't automatically inside SD2's boundary, and a parcel on the edge of town that reads as Larkspur or Tiburon in casual conversation might be.
This matters before a single inspection is scheduled. The rule that governs a sale is decided by which sanitary agency actually serves the parcel, not by the town name on the listing sheet. Confirming that boundary is the first practical step, not an afterthought.
SD2 adopted its Private Sewer Lateral Ordinance, formally Ordinance No. 45, at its board meeting on June 4, 2018, following a 2017 order from the California Regional Water Quality Control Board directing the district to fix damaged and deficient sewer pipes. Aging, cracked, or root-intruded laterals let rainwater and groundwater into the system, which can overwhelm treatment capacity and lead to overflows or partially treated discharge into San Francisco Bay. The ordinance exists to keep that infiltration out, and the point-of-sale trigger is how the district catches problems that would otherwise stay buried for decades.
Four Ways the Clock Starts Without a Listing Photo Taken
A sale is the most common trigger, but it's one of four. A seller who assumes the requirement only shows up once an offer is accepted is already behind.
| Trigger | What it covers |
|---|---|
| Sale or title transfer | Any change of ownership, including standard resale |
| Remodel or permit work | Improvements of $50,000 or more within a cumulative three-year window, ADU legalization or construction, a water meter size change, fire sprinkler installation, or a fixture count change |
| Sewage overflow or malfunction | Any event SD2 staff determines poses a public health threat |
| Capital improvement work | Sewer main upgrades or road paving above a resident's lateral as part of a district or town project |
A seller who pulled a permit for a kitchen remodel two years ago, or added an ADU last spring, may have already tripped this requirement without realizing the sale itself would reference it again. That history is worth checking before assuming the inspection starts fresh with the listing.
The File in Your Garage That Can End the Question Before It Starts
Once a trigger applies, the standard path is a CCTV inspection by a licensed contractor, a written report submitted to the Department of Public Works, and then a pressure test witnessed by a district representative before a Certificate of Compliance is issued. A CCTV recording alone is not enough. Only a passed pressure test earns the certificate.
There's a shortcut, and it lives in old paperwork rather than a new truck in the driveway. The ordinance exempts an owner from a fresh inspection if the lateral already passed a pressure test within the three years before the permit application, the listing, or the change of title. A documented full replacement of the lateral, ten years old or less, can also satisfy the requirement, provided the owner can show proof.
Acceptable proof includes:
- A district-issued Certificate of Compliance from a prior inspection
- A paid contractor invoice showing the date and scope of the work
- Any other documentation the district manager accepts as sufficient evidence of the prior replacement or passing test
For a longtime owner, this is where a five-minute search through old files can save weeks. A binder with a 2019 invoice and a passed pressure test can make the entire question disappear before a contractor is ever called.
The Neighbor Nobody Put on the Listing
Here's the detail that separates Corte Madera's rule from a routine home inspection item. Some of the town's older streets share a single lateral line across two or more properties instead of running a separate pipe to each house. Under the ordinance, when one owner on a shared lateral is triggered, every owner tied to that same line is triggered too.
That means a seller who lists their home can create a compliance obligation for a neighbor who has no plans to sell, no interest in a contractor's estimate, and no reason to think about their sewer line until a letter arrives. The ordinance does build in room for this complexity. Owners on a shared lateral can apply for a one-time, 180-day grace period to schedule the needed testing and any repair or replacement. That period starts on whichever comes first, the date the district issues a notice of repair or the date escrow closes.
It's a fair accommodation, but it only works if someone starts the conversation early. A seller who discovers a shared lateral situation after an offer is already in hand is negotiating on a much tighter runway than one who identifies it before the sign goes in the yard.
What the Test and the Paperwork Actually Cost
The pressure test itself follows one of two accepted methods. An air test holds pressure between 3.5 and 4 psi with no drop allowed over a 15-minute period. A water test uses a riser at least eight feet above the crown of the sewer at the upstream manhole or cleanout, with no water level drop over a full hour. Either way, the district's own representative has to witness the result before a certificate is issued.
According to the town's current published fee schedule, an inspection with no work required runs $150. If the lateral needs a spot repair, the sewer permit that covers the repair and its inspection is currently listed at $300. Fees are adjusted periodically, so confirming the current number with SD2 before budgeting for a listing is worth the phone call.
All work on a private lateral has to go through a contractor holding the right state license classification, and any CCTV inspection has to be performed by a technician with current NASSCO certification, the industry standard for reading pipe condition on video. SD2 recently moved its inspection review onto a cloud-based platform called Forward Lateral, which lets homeowners and their agents track a submitted inspection's status and results as the district works through it, rather than waiting on a phone call to find out where things stand.
A Few Questions Worth Asking
My listing says Corte Madera, but I'm not sure which agency actually serves my address. How do I find out? Jurisdiction follows the parcel, not the town name used in marketing. A property near the Larkspur or Tiburon line can sit inside SD2 or outside it depending on the exact boundary, so confirming the serving agency by address is worth doing before assuming SD2's rules apply, or don't.
I share a lateral with my neighbor and they have no plans to sell. What happens to them if I list my house? Under the ordinance, triggering one owner on a shared lateral triggers every owner on that line. The 180-day grace period exists specifically to give multiple owners time to coordinate testing and repair, with the clock starting at whichever comes first between a district repair notice and the close of escrow.
My lateral was already replaced a few years ago. Do I still need a new inspection? Not necessarily. A passing pressure test within the prior three years, or documented proof of a full replacement ten years old or less, can satisfy the requirement without a new inspection, as long as the district manager accepts the documentation you provide.
A pipe underground doesn't care what season the market is in or what the listing photos look like. It cares about paperwork, boundaries, and whether a neighbor picks up the phone. Getting ahead of all three before a home goes live is the difference between a closing date that holds and one that quietly slips.
If you're weighing a sale in Corte Madera and want a clear-eyed read on what your specific parcel, district, and timeline actually look like, Melissa Crawford is glad to talk it through. Let's Connect.
