Sewer laterals in Costa Mesa: clay pipe, roots and CMSD rules

Costa Mesa incorporated in 1953 and grew fast after World War II, when many people who trained at the Santa Ana Army Air Base came back to settle. The City's 2021 Housing Element shows the pattern: 19.2% of homes were built in the 1950s, 25.4% in the 1960s and 24.1% in the 1970s. About 73% of the housing stock predates 1980.

Vitrified clay pipe was a standard sewer material in that era. It holds up well to sewage itself. Its weak point is the joints. Clay pipe comes in short sections, and each joint is a place where roots can find a gap, where ground movement can offset one section from the next, and where a crack can start. Neighborhoods like Mesa Verde, built mostly in the 1960s and 1970s, have mature trees in their parkways and yards, and roots go where the water is.

Not every lateral is clay. Some homes have had sections replaced with plastic pipe, and some newer buildings were built with plastic from the start. The only way to know what you have, and what shape it is in, is a camera inspection.

On May 2, 2025, a resident spotted sewage leaking from a pipe access point at East Mesa Verde Drive and Golf Course Drive. About 4,000 gallons entered storm drains, and some reached the ocean at the mouth of the Santa Ana River. About 3,000 gallons were tracked through the storm drain system and recovered. The cause, as reported: tree roots had narrowed the sewer line, and cooking grease, possibly from nearby homes, restricted it further. The county temporarily closed ocean waters near the Talbert Channel outfall while bacteria levels were tested, and they reopened May 5.

That spill was in the public system, but the same two things clog private laterals every week.

Grease

Cooking fat, oil and grease go down the drain as a liquid and cool into a solid inside the pipe. Each layer narrows the pipe and catches the next. In a clay lateral with rough joints, grease builds faster. Keep it out of the drain:

• Pour cooled grease into a can or jar and put it in the trash
• Wipe greasy pans with a paper towel before washing
• Do not rely on hot water or dish soap to carry grease away; it re-solidifies downstream
• Use a sink strainer and empty it into the trash

Roots

Roots grow toward moisture, and a leaking clay joint is a steady source. Cutting roots clears the line for a while, but they come back through the same joint. If the camera shows roots at the same spot year after year, the long-term fix is repairing that joint or section.

For restaurants and food businesses, the City's plumbing permit application lists grease interceptors as a work type. Our commercial plumbing page covers that equipment.

A general home inspection usually stops at the drains you can see. The lateral is buried, and in about three out of four Costa Mesa homes it is likely decades old. With Redfin reporting median sale prices of $1,574,319 in 92626 (three months to August 2026) and $1,524,552 in 92627 (three months to September 2026), a sewer problem found after closing is an expensive surprise.

Many Costa Mesa buyers are also future landlords; about 60% of the city's homes are rented. If you are buying a rental, our landlord and property manager plumbing page covers shared laterals in duplexes and small apartment buildings.