As a state that experiences droughts somewhat regularly, California values its water and prioritizes ensuring the quality and safety of its public water supply. As such, all public water systems are required by the State of California to apply for and obtain water board permitting.

In addition to permits, public water systems must strictly comply with state regulations during construction and maintenance so that everyone can enjoy a stable supply of clean water on demand. 

Is It a Public Water System?

A water system is defined as public and, as such, must apply for permits

  • Distributes drinking water to at least 15 contact points. 
  • Delivers a minimum of 25 people daily with drinking water for 60 or more days out of the year

There are 3 categories of public water systems, according to California water boards. Namely, these are

  • Community 
  • Non-community & non-transient 
  • Transient 

Community systems refer to municipal, county, regional, and regulated utility water systems in residential areas. 

Non-community & non-transient systems describe the water supply systems within facilities like schools and businesses that supply their own water. People do not live in these facilities, but they do spend many hours of their day drinking water from these systems. 

Transient systems are mobile potable water systems and are most commonly used in rural areas, where community systems have not been installed. 

Requirements Before Water System Installation


Installing a new public water system is a lengthy process and involves prudent planning. Long before construction begins, the first steps to obtaining a water board permit are as follows. 

  1. Contact existing water systems to evaluate whether a new system is needed or whether an existing system might be used instead.
  2. If research reveals a legitimate need for a new system, conduct a construction cost analysis and long-term maintenance cost projection.
  3. Compile a preliminary technical report containing the information from steps 1 and 2.
  4. Submit the technical report to the local water board at least 6 months before scheduled construction dates. 

Maintenance, Testing & Reporting Requirements After Construction

It is important to set aside a budget to remain in compliance with requirements, as most state-mandated tasks will incur costs. 

The regulatory public water system requirements may vary per applicant depending on the specific needs, challenges, and various influential factors of each project. However, there are many regulations that apply to all applicants. 

To review a list of the specific requirements listed by the State of California, visit this page.

Author Bio-

Building off over 3 decades of experience from working with his father Jim Mayfield (Mayfield Enterprises, Inc.), James mastered the industry in Foremanship for over 15 years on HAZMAT and Superfund Sites throughout Southern California. Among many other partners, we has worked with Project Navigator, RE Solutions, Crew Grading Inc., WSP, SCS Engineers, TRC Corporation, GeoSyntec, NV5 Environmental, Entact Corp, Waste by Rail, Michael Baker, ERRG, O&M Corp, Largo Concrete, B&D Construction, Xebec, WorkSmart, JLL Enterprises, Mayfield Enterprises, Inc., Arcadis, and more. In addition to being a Stanford-educated Professor with over 30 publications and books in several languages (see Academic Resume), James’ real passion lies in Construction-related Project Management, Environmental Cleanups, HAZMAT, Excavation, and Field Labor. We are also Minority-Owned. James Mayfield is a Native American citizen of the Iowa Tribe of Kansas & Nebraska.