Small Drinking Water Systems

The Department of Environmental Health (DEH) Small Drinking Water Systems program's purpose is to protect public health by preventing waterborne diseases, identifying risks of bacteriological, chemical and/or radiological contamination, conducting inspections, providing technical assistance, and working in partnership with the small drinking water systems in San Diego County.

Program Services  

• Provide testing schedules for each small drinking water system at the beginning of each calendar year that are specific for each system based on their water quality reporting requirements.
• Technical assistance
• Coordinate with the California Rural Water Association and the Rural Community Assistance Corporation to provide technical training workshops in San Diego for the local small drinking water system owners and operators
• Provide assistance in obtaining grants and loans for small drinking water systems
• Assist small drinking water systems to be in compliance with the CA Safe Drinking Water Act through regular inspections, providing water quality monitoring schedules, and enforcement of statutes and regulations pertaining to small drinking water systems
• Work in partnership with small drinking water system owners and operators to provide pure and safe drinking water

Water System Classifications

• A Community Water System is a public water system that has 15 to 199 service connections used by year-long residents, or regularly serves at least 25 year-long residents.  Water systems that have 200 or more service connections used by year-long residents are regulated by the State of California Department of Public Health.  An example would be a community with residential homes served by a single water system.
• A Nontransient Noncommunity Water System is a public water system that is not a Community water system and regularly serves at least the same 25 persons during 6 months per year.  An example would be a school or workplace.
• A Transient Noncommunity Water System is a Noncommunity public water system that does not provide water to the same 25 persons during 6 months per year.  An example would be a campground or park.
• A State Small Water System is a public water system that has 5 to 14 service connections, and does not regularly serve potable water to more than 25 individuals for than 60 days out of the year.  An example would be a small residential community with 10 homes served by a single water supply.

Water Quality Monitoring

• Bacteriological Monitoring Requirements:
  All small drinking water systems are required to test for the presence of total coliform bacteria on a regular basis per Federal and State Drinking Water Standards.  Community small drinking water systems and non-community non-transient small drinking water systems are required to test for bacteria on a monthly schedule.  Transient non-community and state small drinking water systems are required to test quarterly for the presence of total coliform bacteria.  All water quality testing is required to be analyzed by a State-certified laboratory.

> EPA Total Coliform Rule

> A Small Systems Guide to the Total Coliform Rule

> Bacteriological Sample Siting Plan

> Emergency Notification Plan

> State Approved Labs for Water Quality Testing

•  Chemical Monitoring Requirements:
  In addition to bacteriological monitoring requirements, small drinking water systems are required to test for chemical constituents that are described in Title 22 California Code of Regulations. Primary Maximum Contaminant Levels (MCL's) address health concerns. Secondary MCL's are aesthetic standards that deal with taste and odor of the water, and not health hazards.  

The general requirements for each system category are as follows:

Community Small Water Systems

Nitrates - Test each source annually
Inorganic Chemicals - Test each source every 3 years
Organic Chemicals (Volatile and Synthetic Organic Chemicals) - Test each source every 3 years
General Mineral / General Physical (Secondary Standards) - Test each source every 3 years
Radionuclides - Test each source for 4 consecutive periods for a scheduled monitoring period
Lead and Copper Rule - 2 consecutive 6-month periods every 3 years. Sample collected from homes in distribution systemDisinfection Byproduct Rule (Only for water systems that use chlorine for disinfection) - Test farthest point in distribution system annually

Non-Transient Non-Community (NTNC) Small Water Systems

Nitrates - Test each source annually
Inorganic Chemicals - Test each source every 3 years
Organic Chemicals (Volatile and Synthetic Organic Chemicals) - Test each source every 6 years
General Mineral / General Physical (Secondary Standards) - Test each source once
Radionuclides – Test each source for 4 consecutive quarters for a scheduled monitoring period
Lead and Copper Rule – 2 consecutive 6-month periods every 3 years. Samples collected from homes in distribution systems

Transient Non-Community (TNC) Small Water Systems

Nitrates – Test each source annually
Nitrites – Test each source every 3 years
Inorganic Chemicals – Test each source once
General Mineral / General Physical (Secondary Standards) – Test each source once

State Small Water Systems

Nitrates – Test each source once, unless directed by the Department
Inorganic Chemicals – Test each source once
Iron, Manganese, Chloride, Total Dissolved Solids – Test each source once

For additional information please contact us or see the following links:

Chemical Contaminants in Drinking Water
Recently Adopted State Regulations
Consumer Confidence Reports
Distribution and Treatment System Operator Certification
TMF (Technical, Management, and Financial Assessment) Requirements

Groundwater Rule (Effective December 1, 2009)