Everything Everywhere All at Once is a great movie. Go watch it. Seriously, I don't even mind if you skip reading this article.
But if you’re still here, we can talk about something else that’s truly everywhere, all at once: water. It’s part of almost everything we do; we’re even made of it. And here in California, we are truly blessed to have great water. That doesn't happen by magic. We have great water because people—engineers, operators, technicians, regulators—work incredibly hard to make it great. And those people are following a blueprint that guides our mission.
When I was thinking of a name for this blog, I kept coming back to 'Title 22'. I didn’t know why for a while; it's niche, vague, and not very descriptive, but it stuck. Now that I’ve been writing more it’s becoming clear. It’s the law of the land for California water. It’s the key to our water quality, and if you've ever practiced for your T5 drinking water certificate, you've probably had to read the damn thing a hundred times.
That blueprint, that key, is Title 22. This article is my attempt to explain what it is, where it came from, and why this dense set of rules is so critical to our future.
What Exactly Is “Title 22”? Decoding the Code
To find our key, you have to navigate the labyrinth of California law. Buried deep within the California Code of Regulations is Title 22, a section officially dedicated to social security and public welfare. For water professionals, however, "Title 22" is specific shorthand for Division 4: Environmental Health. This is the primary regulatory framework governing the state's public water systems, encompassing three critical domains:
Drinking-Water Standards: Setting the safety limits (Maximum Contaminant Levels, or MCLs) for everything from bacteria to chemicals.
Water Recycling Criteria: Establishing the treatment, use, and permitting requirements for using recycled water safely.
Operator Certification: Defining the professional standards and qualifications for the experts who run our water and wastewater systems.
Ask a water engineer about Title 22, and they'll talk about filtration and disinfection. Ask an environmental lawyer, and you might get a different answer. This brings up a legendary point of confusion: the hazardous-waste regulations also live under the same Title number, in Division 4.5. The number of engineering reports and legal briefs that have been misfiled between the two camps over the decades is the stuff of agency lore. For our purposes, we're focused squarely on Division 4—the water side of the family.
A Short History of Title 22: From Humble Beginnings to Modern Blueprint
The regulations we rely on today weren't born overnight. They were built over decades by dedicated professionals responding to the challenges of their time.
The story begins in 1968, with the first reclaimed-water rules appearing in a different section of the code, Title 17. These were the state’s first attempt at setting numeric treatment targets.
The pivotal moment came in 1978, when the Water Reclamation Criteria officially moved to Title 22, marking the birth of the modern standards. The setting for this historic moment wasn't a sterile government office, but a now-demolished Hyatt House ballroom near the Sacramento Capitol. Over three marathon days, engineers and health officials hammered out the draft. These sessions were so intense that when an agency's overhead projector broke, an engineer had to borrow one from the hotel's banquet staff to keep the work going.
This "hotel-room rewrite" was groundbreaking. It established the nation's first numeric virus reduction requirement (a 5-log standard), a pioneering move that predated similar federal EPA rules by nearly a decade.
The 1990s brought another major rewrite. It officially replaced the term "reclaimed" with "recycled" water, a crucial shift in public perception, and introduced language that enabled advanced tertiary treatment, paving the way for the indirect potable reuse projects that are critical to our water supply today.
More recently, the 2014 shift of the Drinking Water program to the State Water Resources Control Board (SWRCB) unified health standards and permitting under a single entity. And in 2023, the landmark adoption of Direct Potable Reuse (DPR) regulations showcased Title 22’s role as a living, evolving document, ready to meet the next generation of water challenges.
These standards weren't created in a vacuum. They were shaped by figures like Dr. George Tchobanoglous, the legendary UC Davis professor whose research provided the technical backbone for the rules, and Jeff Stone, P.E., who led the pivotal 1997-2000 rewrite and is regarded as the "father of modern tertiary standards." Their work, along with that of dedicated regulators like Darrin Polhemus, who shepherded the complex DPR rules through to adoption, continues to influence every project design in California.
Why Title 22 Matters Today: Beyond Compliance
Title 22 is the legal and operational backbone of the California water industry. It is the basis for compliance for the state's approximately 7,400 public water systems and the design foundation for every engineer calculating the required 5-log virus reduction for a recycled water plant. It provides the framework for public health transparency through its tiered public notification rules, ensuring communities are informed about the quality of their water.
But its impact is far broader. Title 22 is an economic catalyst. It is a powerful market force that drives innovation and investment in advanced treatment technologies like membrane filtration, advanced oxidation, and real-time sensors. It generates billions in demand for specialized engineering and environmental consulting services. And by mandating high standards, it creates a pipeline of essential green jobs for a skilled workforce of certified operators, lab technicians, and control system specialists.
Anatomy of the Regulations: A Closer Look at the Chapters
While the full text is dense, a tour of the key chapters shows how comprehensively it governs our water.
Core Water Quality & Treatment:
Chapter 15 (Domestic Water Quality and Monitoring Regulations): This is the heart of the regulations, containing the all-important tables of Maximum Contaminant Levels (MCLs) that define safe drinking water. It also includes the rules for Public Notification (Article 18) and the annual Consumer Confidence Reports (Article 20).
Chapter 17 (Surface Water Treatment): This is the rulebook for any system treating water from a river, lake, or reservoir, detailing the filtration and disinfection techniques required to remove pathogens like Giardia and viruses.
Chapter 15.5 (Disinfectant Residuals, Disinfection Byproducts...) & Chapter 17.5 (Lead and Copper): These are hyper-focused chapters targeting major public health concerns that can arise either from the treatment process itself or from the pipes that deliver water to homes.
System Design, Operations & Permitting:
Chapter 16 (California Waterworks Standards): This chapter governs the physical infrastructure of a water system. It covers everything from system pressure and water main installation to operational plans and the requirements for distribution reservoirs.
Chapter 14 (Water Permits): The foundational chapter defining the entire process for getting, amending, and keeping a permit to operate a public water system.
Chapter 13 (Operator Certification): This section ensures the people running our complex treatment plants are qualified, outlining the grade ladder (T1–T5, D1–D5) and the rigorous continuing education required.
Recycled Water & Advanced Reuse:
Chapter 3 (Water Recycling Criteria): The foundation for all non-potable reuse in California, this chapter details everything from treatment classes to allowable uses for landscape irrigation. (Note: This chapter is located in a different part of Title 22 but is integral to the overall framework).
Chapter 22 (Direct Potable Reuse): The newest and most technologically advanced chapter, setting the stage for the future of California's water supply by establishing the framework to turn recycled water directly into pure drinking water.
Finance & Administration:
Chapter 14.5 (Fees): This chapter outlines the annual fees that public water systems pay to the state. These fees, along with funding from programs like the Safe Drinking Water State Revolving Fund, are what enable the state's oversight and support the multi-million-dollar projects required to comply with all the other chapters.
Where Title 22 Is Headed (2025-2035): Three Futures, Shaped by Regulation
As we peer into the next decade, Title 22 is poised for transformative changes. Rather than a single path forward, we can envision three plausible futures, each shaped by evolving regulations and their ripple effects across the industry.
Scenario 1: The "Adaptive Evolution" Future
Description: The industry continues on its current trajectory. New rules for Direct Potable Reuse (DPR) and PFAS are integrated, but the fundamental regulatory structure remains, with challenges met through incremental improvements.
Key Regulations: Finalization of the Hexavalent Chromium MCL and the addition of new table entries for PFOA and PFOS based on state and federal action.
Implication for Industry: Utilities focus on conventional upgrades and compliance optimization. The Energy-Water Nexus remains a persistent challenge, as meeting stricter standards with existing technologies often increases energy consumption and operational costs.
Scenario 2: The "Technological Disruption" Future
Description: The push for real-time monitoring for DPR, coupled with the need to address microplastics and other contaminants of emerging concern (CECs), drives a rapid adoption of AI/ML for process control, advanced sensors, and modular treatment solutions.
Key Regulations: New rules establishing monitoring and public notification triggers for microplastics, and initial monitoring requirements for the next generation of CECs like pharmaceuticals and personal care products (PPCPs).
Implication for Industry: Operators become more like data scientists, and significant capital is directed toward new technology. In this future, the Energy-Water Nexus is actively addressed, as AI-driven process control and energy-efficient technologies are adopted not just for compliance but for their ability to lower lifecycle costs and improve resilience.
Scenario 3: The "Resource Scarcity & Decentralization" Future
Description: Extreme droughts and chronic water stress accelerate demand for localized reuse, forcing Title 22 to adapt to a more distributed water management landscape with on-site treatment and neighborhood-scale systems.
Key Regulations: A streamlined permitting pathway for decentralized systems and a modernized operator certification program (e.g., new T6/D6 grades) to ensure a workforce capable of managing more complex, distributed systems.
Implication for Industry: New business models like "water as a service" emerge. The Energy-Water Nexus becomes a critical design constraint for these distributed systems, prioritizing passive and low-energy treatment solutions to ensure sustainability at the local level.
Practical Takeaways for Utilities & Designers: Preparing for Tomorrow
How can you prepare for these futures?
To prepare for the Technological Disruption Future, actively seek out and conduct pilot projects for real-time AI-driven process optimization and advanced sensor arrays.
Budget for continuous online monitoring and SCADA upgrades. This is not just a compliance cost but an enabling technology for both the Adaptive Evolution and Technological Disruption futures.
Begin staff up-skilling toward the anticipated T6/D6 competencies. This is a critical step for succeeding in the Resource Scarcity & Decentralization future.
Engage early and often in SWRCB rule-making dockets. Your expert input now helps shape which of these plausible futures becomes the dominant reality.
Tips for Staying Current: Your Regulatory Compass
Official Channels: Regularly monitor the SWRCB’s Regulations webpage and subscribe to the Division of Drinking Water’s email listservs for draft text and workshop announcements.
Community Building: Go beyond official channels. Active participation in industry forums (like those hosted by AWWA, CWEA, and WateReuse) provides early insights and practical interpretations of draft regulations from your peers.
Conclusion: Title 22, A Living Blueprint
Title 22 is far more than a static rulebook; it is California’s living regulatory backbone for safe, resilient, and innovative water supplies. It is a reflection of our history and a roadmap for our future.
The next decade will demand unprecedented adaptability from our industry. By understanding the forces shaping Title 22—from direct potable reuse to emerging contaminants and the rise of distributed systems—you can not only navigate compliance but actively future-proof your projects, your operations, and your career.
What role will you play in shaping California's water future? Share your thoughts and experiences in the comments below.
