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Small Water Systems FAQs


What are Small Water Systems and how are they classified?

Small Water Systems supply drinking water to small communities between 2 and 199 service connections; or serve 25 or more people at least 60 days out of the year. Small water systems are required to meet water quality standards of the Safe Drinking Water Act. Contra Costa Environmental Health permits and regulates all Small Water Systems in Contra Costa County, which include small Public Water Systems (Community, Non-transient Non-Community, and Transient Non-Community Systems) and Non-Public Water Systems (State Small and County Small Systems).

Community Water System - Serves drinking water to at least 15 service connections used by yearlong residents or regularly serves at least 25 yearlong residents. Examples are a Mobile Home Park or residential subdivision.

Non-transient Non-community - Serves drinking water to 25 or more of the same people (non-residential) over 6 months per year. Examples are a school or business.

Transient Non-community - Serves drinking water to 25 or more individuals at least 60 days out of the year, but does not meet the requirements of a community or non-transient non-community water system. An example is a restaurant, campground, or church.

State Small System - Serves drinking water to between 5 and 14 service connections. An example is a subdivision of 8 homes.

County Small System - Serves drinking water to between 2 and 4 service connections. (Two single-family residences on one parcel is not considered a small water system.) An example is two neighbors on separate parcels sharing a well.

What are the Sampling Frequencies (bacteriological, chemical & radiological) for the different classifications?

Community Water Systems:

Bacteriological - Monthly
Chemical - Once every 3 years
Nitrates - Annually
Radiological - Every 3 Years

Non-Transient Non-Community Systems:

Bacteriological - Monthly
Chemical - Once every 3 years
Nitrates - Annually
Radiological - Every 3 Years

Transient Non-Community Systems:

Bacteriological - Every 3 months
Chemical - Initial Sampling only
Nitrates - Annually
Radiological - Initial sampling only

State and County Small System:

Bacteriological - Every 3 months
Chemical - Initial Sampling only
Nitrates - Annually
Radiological - Initial sampling only

How do I obtain an exemption from organic chemical monitoring?

An exemption from organic chemical monitoring may be requested if initial sampling has demonstrated that there were no organic chemicals detected in the water supply and that there is no historical record of the use or manufacture of organic chemicals in the area.

What are the requirements regarding chlorination?

Chlorination is one method to disinfect the water supply. A Small Water System is not required to chlorinate the water unless the water source or distribution system has had problems with bacterial contamination. If chlorination is required, the water system must maintain chlorine residual of 0.2 ppm throughout the distribution system (max 4.0 ppm), and the chlorine levels must be recorded daily. All chemicals and additives used for drinking water treatment must have NSF Standard 60 approval.

What are the regulations regarding the use of surface water?

Surface Water must comply with all drinking water quality standards of the Safe Drinking Water Act. To achieve compliance, the Surface Water Treatment Rule requires water systems to provide multibarrier treatment (including filtration and disinfection) to ensure removal of giardia, cryptosporidium, and viruses from the water.

What is the Cross Connection Control Program?

The Cross Connection Control Program consists of operating rules and maintenance procedures that a small water system takes to prevent water from non-approved sources or any substance, from entering the small water system. Cross Connection Control can be achieved through the use of approved backflow prevention devices and the annual maintenance and testing of those devices.

What are Consumer Confidence Reports?

A Consumer Confidence Report (CCR) is an annual water quality report prepared by all community and non-transient non-community water systems for distribution to their customers. The CCR includes information on the source water, the levels of any detected contaminants, any associated health effects, and compliance with drinking water regulations.

What is the TMF capacity requirement?

Technical Managerial Financial (TMF) capacity is the ability of a Small Water System to provide a safe and reliable drinking water supply to the customers. TMF capacity assessment is required for new small public water systems, public water system undergoing a change of ownership, water systems requesting financial assistance or as required through enforcement actions.

What is the SWAP Program?

The Source Water Assessment Program (SWAP) is a study and report of each water system that provides basic information about the drinking water source and identifies any possible contaminating activities in the area.