Part I. General, Water Well Standards

Section 1. Definitions.

Note that technical terms are defined in Appendix A.

1. Well or Water Wells. As defined in Section 13710 of the Water Code, well or water well:

   "…means any artificial excavation constructed by any method for the purpose of extracting water from, or injecting water into, the underground. This definition shall not include: (a) oil and gas wells, or geothermal wells constructed under the jurisdiction of the Department on Conservation, except those wells converted to use as water wells; or (b) wells used for the purpose of (1) dewatering excavations during construction, or (2) stabilizing hillsides or earth embankments."

2. Community Water Supply Well. A water well used to supply water for domestic purposes in systems subject to Chapter 7, Part 1, Division 5 of theCalifornia Health and Safety Code. Included are wells supplying public water systems classified by the Department of Health Services as "Noncommunity water systems" and "State small water systems" (California Waterworks Standards, Title 22, California Administrative Code). Such wells are variously referred to as "Municipal Wells", "City Wells", or "Public Water Supply Wells".
3. Individual Domestic Well. A water well used to supply water for the domestic needs of an individual residence or systems of four or less service connections (or "hook-ups" as they are often called).
4. Industrial Wells. Water wells used to supply industry on an individual basis (in contrast to supplies provided through community systems).
5. Agricultural Wells. Water wells used to supply water only for irrigation or other agricultural purposes, including so-called "stock wells".
6. Recharge or Injection Wells. Wells constructed to introduce water into the ground as a means of replenishing groundwater basins, repelling the intrusion of sea water or disposing of waste water. (See Note 1)
7. Air-conditioning Wells. Wells constructed to return to the groundwater which has been used as a coolant in air conditioning processes. Because the water introduced into these wells is degraded (from the standpoint of temperature), such wells have been construed as waste discharges and are, therefore, subject to the water quality control laws (Division 7 of the Water Code and Division 5 of the Health and Safety Code).
8. Horizontal Wells. Water wells drilled horizontally or at an angle with the horizon (as contrasted with the common vertical well). This definition does not apply to horizontal drains or "wells" constructed to remove subsurface water from hillsides, cuts, or fills (such installations are used to prevent or correct conditions that produce landslides).
9. Exploration Hole (or Boring). An uncased, temporary excavation whose purpose is the determination of hydrologic conditions at a site.
10. Test Wells. Wells constructed to obtain information needed for design of other wells. Test wells should not be confused with "exploration holes", which are temporary. Test wells are cased and can be converted to other uses such as groundwater monitoring and, under certain circumstances, to production wells.
11. Inactive or Standby Well. A well not routinely operating, but capable of being made operable with a minimum effort.
12. Enforcing Agency. An agency designated by duly authorized local, regional, or State government to administer and enforce laws or ordinances pertaining to the construction, alteration, maintenance, and destruction of water wells. The California State Department of Health Services or the local health agency is the enforcing agency for community water supply wells.

1. Included are wells used for the injection of reclaimed waste water. Injection wells are also used to dispose of unusable waste water into formations containing water of unusable quality (such as highly mineralized waters) or dry, nonproductive formations. These latter wells can penetrate usable groundwater zones but are not permitted to open into usable water (Chapter 7, Division 7, California Water Code; Section 4458, California Health and Safety Code; and Chapter 1, Division 3, California Public Resources Code). "Dry" wells, "drainage" wells, and sewer wells also fall into this category. Their existence and operation is also subject to the aforementioned provisions of the State law.

Section 2. Application to Type of Well

Except as prescribed in Section 3 and Section 4 (following) these standards shall apply to all types of wells described in Section 1. Before a change of use is made of a well, for example, an agricultural well converted to use as a community water supply well, compliance shall be made with the requirements for the new use as specified herein.

Section 3. Exemption Due to Unusual Conditions

If the enforcing agency finds that compliance with any of the requirements prescribed herein is impractical for a particular location because of unusual conditions or if compliance would result in construction of an unsatisfactory well, the enforcing agency may waive compliance and prescribe alternative requirements which are "equal to" these standards in terms of protection obtained.

Section 4. Exclusions

The standards prescribed in Part II, "Construction", do not apply to exploration and test holes. However, the provisions of Section 7 "Reports" (following) and Part III, "Well Destruction", do apply to these holes.

Springs are excluded from these standards. Methods which can be used to protect water supplies furnished by springs and infiltration galleries are described in "Manual of Individual Water Supply Systems", U.S. Environmental Protection Agency, Office of Drinking Water (EPA-430/9-74-007).

Section 5. Special Standards

1. In locations where existing geologic or groundwater conditions require standards more restrictive than those described herein, such special additional standards may be prescribed by the enforcing agency. 
2. Special standards are necessary for the construction of recharge or injection wells, (See Note 1) horizontal wells and other unusual types of wells. Design of these wells is subject to the approval of the enforcing agency.

Section 5 Notes:

1. A program to protect underground drinking water sources from endangerment by the subsurface emplacement of fluids through well injection is required under the Federal Safe Drinking Water Act (Public Law 93-523) signed into law December 16, 1974. On June 24, 1980, the U.S. Environmental Protection Agency issued rules and regulations establishing technical criteria and standards governing the construction of injection wells. Revisions were made August 27, 1981, and October 1, 1981. These regulations are Part 146 of Title 40, Protection of Environment, of the Code of Federal Regulations (40CFR146).

Section 6. Well Drillers

The construction, alteration, or destruction of wells shall be performed by contractors licensed in accordance with the provisions of the Contractor’s License Law (Chapter 9, Division 3, of the Business and Professions Code) unless exempted by that act.

Section 7. Reports.

Reports concerning the construction, alteration, or destruction of water wells shall be filed with the California Department of Water Resources in accordance with the provisions of Sections 13750 through 13755 (Division 7, Chapter 10, Article 3) of the California Water Code. See Note 1)

Section 7 Notes: