The Title 22 Engineering Report: The Real Bottleneck in California Recycled Water Projects

What is a Title 22 engineering report?

It is the engineer's proof that a recycled water system complies with California's Water Recycling Criteria, from the plant to the last sprinkler.

No approved report, no recycled water. Under 22 CCR §60323, no person may produce or supply recycled water for reuse from a water reclamation plant without a Department-approved engineering report. A qualified engineer licensed in California and experienced in wastewater treatment prepares it.

The report describes the design of the reclamation system and shows how it complies with the regulations. It must also carry a contingency plan that keeps untreated or inadequately treated wastewater from reaching a use area.

Who reviews it, and who issues the permit?

DDW reviews the public health side. A Regional Water Quality Control Board issues the permit.

The State Water Board's recycled water program page says the nine Regional Boards issue recycled water permits, as waste discharge requirements or water reclamation requirements, and coordinate with DDW on health regulations. Most nonpotable projects enroll under the statewide general order, as our post on Order WQ 2016-0068-DDW explains.

Then there is the local purveyor. The water district or city that will deliver recycled water often has its own rules for user agreements, meters and pipe standards. Three reviewers reading one report is where most of the time goes.

Why does the report stall projects that looked simple?

Because a concept plan can say "irrigate the common areas," and the report cannot.

The report needs decisions the concept never made. A reviewer needs exact use area boundaries, the access condition at each one, the pipe routes and the person responsible at each site. If those were left open during planning, report preparation becomes the phase where they get made, under review pressure, with redesign on the critical path.

The fix is sequence. Treat the report's contents as a design checklist from the start, not a document you write after the drawings are done.

How does the use area set the treatment level?

Public access decides it. The more likely people are to contact the water, the higher the treatment required.

Under 22 CCR §60304, surface irrigation of parks, playgrounds, school yards, residential landscaping and unrestricted-access golf courses requires disinfected tertiary recycled water. Cemeteries, freeway landscaping and restricted-access golf courses can use disinfected secondary-23 water.

Mixed sites follow the strictest area. A business park with a public lawn next to a fenced detention basin needs the plant, or the use area plan, to match the lawn. If a later site plan revision opens a restricted area to the public, the treatment basis in the report no longer fits what was built.

What does a dual-plumbed building add?

A second report section with its own detail, and a test every four years.

Under 22 CCR §60314, a report for a dual-plumbed system adds:

• the facilities, their number, location and type, and the daily population each serves;
• a map of the use area boundaries and the party responsible for the system at each site;
• plans showing recycled and potable pipe routes, public outlets and fixtures, and the backflow devices;
• the methods that keep the two systems apart, including the pressure, dye or other test run every four years.

A master plan report can cover several buildings, and plans for each building can follow later, before recycled water reaches it. That flexibility helps phased projects, but only if the master plan is real.

What reliability features do reviewers look for?

Proof that a treatment failure never reaches a use area.

Article 10 of the criteria sets reliability requirements by treatment level. For example, 22 CCR §60341 describes emergency storage or disposal: short-term retention for at least 24 hours, long-term storage for at least 20 days, backup power for most equipment, and automatic diversion with a manual reset after a process failure. Your report names which reliability option the plant uses and shows it on the drawings.

Why do user agreements slow multi-tenant projects?

Because the report has to say who is responsible at each site, and on a multi-tenant project that takes signatures.

An HOA, a business park or a campus with several owners needs each user to accept onsite duties: signs, inspections, supervisor contacts and reporting. A report filed while those agreements are still being negotiated describes responsibilities nobody has accepted yet. Start the agreements when you start the report.

Are you ready to submit the report?

You are ready when you can answer yes to all six.

1. Is every use area mapped, with its access condition and required treatment level?
2. Does the treatment train meet the strictest use area on the site?
3. Are recycled and potable pipe routes, outlets and backflow devices on the plans?
4. Is the reliability option and contingency plan defined and drawn?
5. Are user agreements or a supervisor named for every site?
6. Have DDW, the Regional Board and the purveyor each seen the approach before submittal?

DDW publishes guidance titled Preparation of an Engineering Report for the Production, Distribution and Use of Recycled Water (June 2023). Use its outline.

A note on limits: this is general education from Title 22 and State Water Board guidance as published in October 2026. The State Water Board plans further updates to the nonpotable criteria, so check the current rule, your Regional Board and your purveyor for your project.

Frequently asked questions

When is a Title 22 engineering report required?

Before anyone produces or supplies recycled water for reuse from a water reclamation plant, under 22 CCR §60323.

Who can prepare a Title 22 engineering report?

A qualified engineer licensed in California and experienced in wastewater treatment, per §60323(b).

I'm developing a business park in the Bay Area and the city will deliver recycled water for landscaping. Do I need my own engineering report?

Ask the purveyor first. Its system may already be covered by an approved report, and §60314(b) lets a master plan report cover several sites. Expect to supply site plans and sign a user agreement either way. A dual-plumbed building adds the §60314 detail.

I run a small civil firm in California and my client wants recycled water for a public park. What decides the treatment level?

Public access. Park irrigation requires disinfected tertiary recycled water under §60304(a), so confirm the source plant produces it before you design the irrigation system.

Related resources

• Title 22 Recycled Water in San Jose: The Fastest Path to Water Approvals
• Permitting Land Application: Choosing Between WDRs and Recycled Water Rules
• California’s New Direct Potable Reuse Rules: What the Regulations Actually Require and Where Implementation Stands
• The 120-Day WDR Rule in California, Explained for Developers

Preparing a Title 22 engineering report that won't stall in review?

We settle the use areas, piping and cross-connection design before the report goes in, so review confirms decisions already made. Talk with an engineer about your project.

We specialize in:

• Title 22 engineering reports
• Recycled water distribution and purple pipe design
• Use area mapping and demand estimates
• Cross-connection control planning
• Wastewater treatment design for reuse
• Site civil engineering for land development

Modern Engineering Solutions, McKinney, Texas. Contact: (214) 833-6748 or mod-eng.com