Top Plumbing Code Upgrades Required in San Mateo & Santa Clara Counties

Homeowners and business owners across the Bay Area are often surprised to learn how quickly local plumbing codes evolve. Even if your home’s plumbing system “still works,” it may no longer meet current safety or building standards. Updated plumbing codes aren’t just about compliance—they’re about protecting your property, ensuring water efficiency, and maintaining health and safety.

At Repipe Champions Plumbing and Rooter Inc., we regularly work with city inspectors throughout San Mateo County and Santa Clara County, ensuring every repipe, sewer replacement, and fixture installation meets or exceeds code. This guide will help you understand the most important plumbing code updates, why they matter, and how to make sure your home or business remains fully compliant.

Why Plumbing Code Upgrades Matter

Plumbing codes are regulations that define how systems must be designed, installed, and maintained to protect public health and ensure efficient water and waste management. These codes are established primarily by the California Plumbing Code (CPC), which is updated every three years.

Local building departments—such as the City of San Mateo Building Division, San Jose Department of Planning, Building & Code Enforcement, and Santa Clara County Building Inspection Office—adopt the CPC but can enforce stricter local amendments.

Failing to meet plumbing code can lead to:

• Failed inspections during remodels or property sales

• Water contamination or cross-connection hazards

• Insurance claim denials for water damage

• Fines or stop-work orders during renovations

If you live in an older home (especially one built before 1980), your plumbing system is almost certainly out of compliance in several areas.

1. Lead-Free Plumbing Materials

In recent years, one of the most significant changes to California’s plumbing code has been the requirement for lead-free materials.

Under AB 1953 and subsequent updates to the Safe Drinking Water Act, all pipes, fittings, and fixtures used for potable water must contain no more than 0.25% lead content.

Why It Matters:

Older homes often have brass or galvanized steel fittings that can leach lead or zinc into the water supply, especially when corrosion occurs. Upgrading to PEX or copper piping not only brings your system up to code but also ensures cleaner, safer drinking water for your family.

Repipe Champions uses only lead-free, California-approved fittings on all installations.

2. Earthquake Shut-Off Valves

Both San Mateo County and Santa Clara County now strongly encourage or require seismic gas shut-off valves on all residential and commercial gas systems. These devices automatically close the gas supply if significant ground movement is detected, preventing fires or explosions following an earthquake.

Where Required:

Cities including Redwood City, San Mateo, Palo Alto, Los Gatos, and San Jose have adopted specific local ordinances for new installations, remodels, or property transfers.

Why It Matters:

California sits on multiple active fault lines. Installing an automatic shut-off valve is an affordable, one-time upgrade that could save lives and property in a major quake.

At Repipe Champions Plumbing and Rooter Inc., we install and permit earthquake shut-off valves that meet California seismic standards (CSA 6.19 / ANSI Z21.70).

3. Properly Sized and Vented Drain Systems

The CPC now requires modern venting and drainage configurations designed to prevent sewer gas escape and ensure waste flows efficiently.

Older systems often use improper slope angles, undersized piping, or outdated venting (such as S-traps or crown vents). These no longer meet code and can cause:

• Gurgling drains

• Sewer gas odors

• Slow drainage or backflow issues

Current Standard:

Drain lines must slope at ¼ inch per foot, and all fixtures must have a code-approved vent connection to maintain air pressure balance.

When Repipe Champions performs trenchless sewer replacements or drain upgrades, we ensure every line meets modern slope and venting requirements, verified by city inspection.

4. Water Heater Code Compliance

Water heaters are one of the most heavily regulated fixtures in California plumbing codes. If yours was installed more than 10 years ago, it’s likely out of compliance.

Recent Code Requirements Include:

• Seismic strapping: Two straps — upper ⅓ and lower ⅓ of the tank — must be secured to wall studs.

• Expansion tank: Required when a home has a closed water supply system to prevent excess pressure buildup.

• Venting and combustion air: Proper venting and clearance must be maintained to prevent carbon monoxide buildup.

• Drain pan and discharge line: Must terminate to an approved drain point, not onto the floor or driveway.

• Temperature and pressure (T&P) relief valve: Must discharge within 6 inches of the floor or approved drain receptor.

Why It Matters:

Incorrectly installed or unstrapped water heaters pose serious fire and flood hazards. Every Repipe Champions installation is permitted, strapped, vented, and inspected for full code compliance.

5. Backflow Prevention Devices

Backflow prevention assemblies are now required on most commercial properties and new residential builds where there’s a risk of contaminated water entering the potable supply.

Examples include:

• Irrigation systems

• Fire sprinkler connections

• Commercial dishwashers or boilers

• Hose bibbs without vacuum breakers

San Mateo County Environmental Health Services and Santa Clara Valley Water District both enforce annual testing and certification for backflow devices.

For homeowners, simple anti-siphon hose bibbs or vacuum breakers meet code. For businesses, reduced pressure zone (RPZ) assemblies are required.

Repipe Champions installs and tests all types of backflow prevention devices, providing documentation for city inspection or compliance renewal.

6. Trenchless Sewer Line Standards

As trenchless technology becomes more common, cities have tightened regulations to ensure structural integrity and proper installation.

Under CPC Chapter 7 and ASTM F1216, trenchless pipe bursting or cured-in-place piping (CIPP) must:

• Use certified epoxy or HDPE materials

• Maintain grade consistency

• Include video inspection before and after installation

• Pass a leak test or air pressure test

Local Variations:

Cities like San Jose, Burlingame, and Palo Alto may require city lateral inspections up to the main connection in the street.

At Repipe Champions, all trenchless replacements include video documentation, slope verification, and full permitting, ensuring the project passes inspection on the first attempt.

7. Water Efficiency Standards

California has some of the nation’s strictest water conservation codes, impacting everything from toilets to showerheads.

Recent CPC and CALGreen requirements include:

• Toilets: 1.28 gallons per flush (GPF) maximum

• Showerheads: 1.8 gallons per minute (GPM) maximum

• Lavatory faucets: 1.2 GPM maximum

• Kitchen faucets: 1.8 GPM maximum

If your fixtures are older, replacing them with WaterSense-certified models can dramatically reduce water waste and lower utility bills.

In some San Mateo County cities, fixture upgrades are mandatory at the point of sale or major remodel.

8. Gas Line Sizing and Pressure Testing

Gas line installations and repairs must now follow stricter sizing and pressure-testing rules. The CPC requires:

• CSST (corrugated stainless steel tubing) to be bonded and grounded properly

• Black iron or copper tubing sized according to total BTU load and distance

• 15 psi pressure test for 15 minutes on new installations before inspection

Improper sizing can cause low gas pressure and appliance malfunctions. All Repipe Champions gas work is pressure-tested, permitted, and inspected for safety.

9. Proper Shut-Off Valves and Accessibility

Every plumbing fixture—faucet, toilet, water heater, and appliance—must have an accessible shut-off valve.

Homes built before 1990 often lack these valves, making maintenance and emergency response difficult. Current code also requires that main water shut-off valves be clearly labeled and easily accessible.

When Repipe Champions performs whole-house repipes, we include new angle stops, hose bibbs, and a labeled main shut-off as standard.

10. Pipe Insulation and Energy Efficiency

Under California Title 24 Energy Standards, all hot water lines must be insulated to improve efficiency and reduce heat loss.

Insulation thickness varies depending on pipe diameter and temperature range but typically requires:

• ½-inch insulation for pipes up to ¾ inch diameter

• 1-inch insulation for larger lines or outdoor runs

Proper insulation not only saves energy but also prevents condensation and premature pipe wear.

11. Permit and Inspection Requirements

Both San Mateo County and Santa Clara County require plumbing permits for major work, including:

• Whole-house repiping

• Sewer or gas line replacement

• Water heater installation

• New fixture rough-ins

Permits ensure your project is inspected for code compliance. Skipping this step can result in fines or problems when selling your property.

Repipe Champions Plumbing and Rooter Inc. handles all permits and coordinates directly with local building departments — saving homeowners the hassle of paperwork and scheduling.

12. Bringing Older Homes Up to Code

Many Bay Area homes built before 1975 have outdated plumbing systems that are both inefficient and non-compliant. Common required systems that require plumbing code upgrades:

• Galvanized steel water lines

• Cast iron sewer laterals

• Missing cleanouts

• S-traps instead of P-traps

• No anti-siphon protection

A full repipe or sewer replacement instantly brings the property up to modern standards while improving performance and reliability.

We provide free inspections for homeowners looking to identify outdated or unsafe plumbing systems.

Final Thoughts on Plumbing Code Upgrades

Staying up to date with plumbing codes is essential for maintaining a safe, efficient, and insurable property. Whether you’re renovating a home, replacing old pipes, or buying a new property in San Mateo County or Santa Clara County, working with a licensed plumbing contractor ensures your system is compliant and built to last.

At Repipe Champions Plumbing and Rooter Inc., we’re proud to provide fully permitted, code-compliant repipes, sewer replacements, water heater installations, and gas line repairs throughout the Bay Area.

Our team handles permits, inspections, and warranty-backed work so you can rest easy knowing your home meets California’s latest plumbing standards.