About Small Water Systems and Wells

Clean water is one of the most important factors in human health. We need clean water for drinking, bathing, cooking, and cleaning. Most people receive their water from a public water system through a pipe that comes into their home. Other people may have a private well on their property.

Water systems deliver water to homes, schools, and businesses for drinking and other potable water uses. The systems may have storage tanks, water wells, treatment facilities, delivery pipelines, and service connections at homes and other buildings. In Los Angeles County, small water systems are those with less than 200 service connections.

Water wells have been used by humans for thousands of years. They are structures that allow access to water that is found below ground. Special care must be taken to have wells that are properly constructed, maintained, and tested to make sure that water is safe for drinking or other potable uses.

The Drinking Water Program of Environmental Health permits, inspects, and monitors small public water systems with less than 200 service connections, wells, and exploratory holes in Los Angeles County. Other services are detailed in the Business Information and Documents.

The Drinking Water Program is responsible for enforcing California’s Drinking Water Standards in public water systems with less than 200 service connections throughout Los Angeles County. We review and approve production and non-production wells in Los Angeles County, except for those located in the cities of Pasadena, Long Beach, or Vernon.  Those cities each have their own health departments.

Los Angeles County requires property owners to demonstrate that their private domestic water well provides an adequate supply of potable water suitable for domestic use.

For Small Water Systems

Los Angeles County Code
Consumer Confidence Reports
Template for Public Notifications: boil orders
EPA Total Coliform Rule
Recently Adopted State Drinking Water Regulations

Technical Managerial Financial Assessment for Public Water Systems
Drinking Water Source Assessment
United States EPA Maximum Contaminant Levels
Los Angeles County's Small Water System Water Quality Monitoring

Private and Commercial Water Wells

To apply for a permit and learn more about requirements for water wells, please review the guides below.

List of Accredited Labs
Licensed Water Haulers
Well testing

These websites provide additional insight regarding analytical methods, drinking water standards, consumer confidence reports, water conservation efforts and other valuable information for the private well owners.

Private Drinking Water Wells (EPA)
Private Ground Water Wells (CDC)
Water Quality in Private Domestic Wells (State Water Board)
A Guide for Private Domestic Well Owners

General Information

Frequently Asked Questions: Chromium-6 in Drinking Water
Questions and Responses for Presence of Chromium-6 in Local Water Supplies
Presence of Chromium 6 in Local Water Supplies Presentation
Reporting Requirement for Hexavalent Chromium (July 20, 2015)
Arsenic in Drinking Water Frequently Asked Questions

Disinfection of Onsite Water Storage Tanks: Best Practices Fact Sheet
Notice Regarding Changes in Horizontal Setback Requirements
Application for Well Reuse after The Woolsey Fire
California Well Standards, Combined
California Department of Water Resources | Citizen Access Portal

California Department Of Water Resources
California State Water Resources Control Board
California State Water Resources Control Board GeoTracker (Google Chrome Only)
California Department of Toxic Substances Control EnviroStor (Google Chrome Only)

Non-Production Wells and Exploratory Holes

Monitoring Wells

Monitoring wells are constructed to observe conditions at defined or required locations. Monitoring well locations are selected based on known or expected hydrologic, geologic, and water quality conditions and the location of pollutant or contaminant sources. Monitoring wells frequently need to be located close to or within areas of pollution or contamination.

Cathodic Protection Well

Cathodic protection well is any artificial excavation in excess of 50 feet constructed by any method for the purpose of installing equipment or facilities for the protection electrically of metallic equipment in contact with the ground, commonly referred to as cathodic protection.

Geothermal Heat Exchange Well

A geothermal heat exchange well is any uncased artificial excavation, by any method, that uses the heat exchange capacity of the earth for heating and cooling, in which excavation the ambient ground temperature is 30 degrees Celsius (86 degrees Fahrenheit) or less, and which excavation uses a closed loop fluid system to prevent the discharge or escape of its fluid into surrounding aquifers or other geologic formations. Geothermal heat exchange wells include ground source heat pump wells.

Test Wells (Hole)

Test wells are 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.

Recharge, Injection or Air Conditioning Wells

Wells constructed to introduce water into the ground as a means of replenishing groundwater basins, repelling the intrusion of seawater, disposing of wastewater, or returning to the groundwater which has been used as a coolant in air conditioning processes. These wells are constructed under the jurisdiction of Regional Water Quality Control Boards under the authority of the California Water Code and California Public Resources Code. They also include "dry" wells, "drainage" wells and "sewer" wells.

Exploration Hole (Boring) and Soil Vapor Probe

Exploration holes (or Borings) and Cone Penetrometer Tests (CPT) for the purpose of determining hydrological conditions at a site, which are conducted at a depth greater than 10 feet below ground surface in the vadose zone or at any depth in the saturated zone, are required to submit a work plan and application to the Drinking Water Program. If an exploration hole (or Boring) or Cone Penetrometer Test (CPT) does not exceed 10 feet below ground surface and is not located within the saturated zone, a work plan and application is not required.

No permit is required for Soil Vapor Probe installed in vadose zone. A permit will be required if they reach saturated zone during the installation of the probe.

Shallow Anodes

Installation of anodes for pipeline protection at a depth of less than 50 feet deep are "legally" considered "shallow anodes", not cathodic protection wells. Shallow anodes do not require a well permit.

Dewatering / Stabilizing Wells

Dewatering or stabilizing wells are those wells installed for the purpose of dewatering excavations during construction or stabilizing hillsides and earth embankments. These wells do not require a well permit.

Oil and Gas Wells or Geothermal Wells Constructed in the State's Geothermal Resources Areas

Wells constructed under the jurisdiction of the Department of Conservation, California Geologic Energy Management Division shall not require a well permit.

Soil Vapor Extraction Wells

Soil vapor extraction wells use vacuum pressure to remove volatile and some semi-volatile contaminants (VOCs and SVOCs) from the soil. These wells may need a well permit. If these types of wells unexpectedly penetrate a subsurface aquifer, the contractor, driller, or consultant must contact Public Health for the purpose of evaluating the need for standard measures to protect the aquifer and for a well permit

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Report a Problem

Report problems with small water systems and wells by calling Environmental Health at (800) 777-9995 or File a Complaint Online. Environmental Health will not ask you about your immigration status and you can file a report without giving your name.

Contact Us

Monday - Friday
8:00am - 5:00pm

Tel: (626) 430-5420
Fax: (626) 813-3016

County of Los Angeles Public Health
Environmental Health
Drinking Water Program
5050 Commerce Drive
Baldwin Park, CA 91706