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Am I a "Public Water System"?

If you supply water to other people, even if it's bottled, you might be a public water system (PWS). Find out if you are a PWS and, if so, what requirements you must meet.

Definition of a Public Water System

If you provide water to the public, you may be a public water system (PWS). State and federal regulations define PWSs [30 TAC §290.38(71), Fed Ref]

A PWS provides potable water for the public’s use. A system must be a certain size to be considered public:

  • it must have at least 15 service connections


  • serve at least 25 individuals for at least 60 days out of the year.

This includes folks that live in houses served by a system, but can also include people that don’t live there. For instance, people served could include employees, customers, or students.

There are three basic types of public water systems.

Community water system (C)

– A public water system which has a potential to serve at least 15 residential service connections on a year-round basis or serves at least 25 residents on a year-round basis [30 TAC §290.38(15)]. Most municipalities meet this definition, so do some boarding schools and prisons.

Nontransient noncommunity water system (NTNC)

– A public water system that is not a community water system and regularly serves at least 25 of the same persons at least six months out of the year [30 TAC §290.38(58)]. Many factories, schools, camps, child care facilities, recreational vehicle parks with long-term residents, and other businesses are NTNCs. Businesses that purchase and redistribute potable water may fall under the regulations for PWSs if the utility that provides them with water does not have sanitary control over their facilities [30 TAC 290.102(a)].

Transient noncommunity water system (TNC)

– A public water system that is not a community water system and serves at least 25 persons at least 60 days out of the year, yet by its characteristics, does not meet the definition of a nontransient noncommunity water system.[30 TAC §290.38(84)] Parks, recreation parks, convenience stores, restaurants and other businesses often are TNCs.

Public water systems are assigned seven-digit PWS IDs. All of the Public Drinking Water Section correspondence and documentation references this PWS ID. The first three digits in the PWS ID represent the Texas county that the facility is located in. Texas’ 254 counties are numbered alphabetically from Anderson (001) to Zavala (254). You can find documents about a PWS by using its PWS ID.