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Noncommunity Water Systems (NCWS)

The Pennsylvania Department of Environmental Protection (DEP) has requirements to ensure safe drinking water is available to the public. These requirements apply to both community and noncommunity public water systems. While community systems provide drinking water to places where people live (e.g. municipalities, mobile home parks, sub-divisions), noncommunity water systems provide drinking water to the public at other locations.

Public Water Systems (PWSs) are water systems that provide water to the public for human consumption. A water system is a PWS if it serves at least 15 service connections or regularly serves an average of at least 25 people for at least 60 days of the year. PWSs are classified as community PWSs or noncommunity PWSs. Water for human consumption includes water that is used for drinking, bathing and showering, cooking, dishwashing or maintaining oral hygiene.

Community Water Systems (CWSs) are public water systems that serve water year-round to residents. Examples of CWSs include water systems for mobile home parks and municipal water systems.

Noncommunity water systems (NCWSs) are public water systems that have their own water sources, or provide additional treatment to municipal water, and supply drinking water to an average of 25 or more people per day. NCWSs may be further classified as transient water systems or nontransient water systems.

Transient noncommunity water systems (TNCWS) serve an average of 25 people or more per day for at least 60 days of the year, but not necessarily the same people or on a regular basis. The population is considered transient because they are only there for a short period of time. Examples of TNCWS include restaurants, hotels, service stations, campgrounds, and resorts.

Nontransient noncommunity water systems (NTNCWS) regularly serve at least 25 of the same people at least 6 months of the year. The population is considered nontransient because they are there for an extended period of time. Examples of a NTNCWS include schools, factories, industrial parks, office buildings, and hospitals.

To ensure drinking water standards are met, all NCWSs are required to obtain approval from DEP prior to construction or operation. Approval to operate may be granted by the following:

1. Noncommunity Water Systems Application - A NCWS is eligible for this type of approval if the sources of supply for the system are groundwater sources requiring treatment no greater than hypochlorite or ultraviolet light disinfection to reduce total coliform bacteria concentrations to undetectable levels in the finished water, and otherwise provide water of a quality that meets the primary MCLs established under Subchapter B (relating to MCLs, MRDLs or treatment technique requirements). A well drilled by a Pennsylvania-Licensed well driller is the only acceptable source for the Noncommunity Water System Application.

NCWSs that wish to install treatment for secondary MCLs (e.g. iron, manganese) and the raw water concentrations for the contaminate are below any EPA Drinking Water Health Advisory may still qualify for the Noncommunity Water System Application process.

Note: Under 25 Pa. Code § 109.505(a), the Department retains the right to require a NCWS that meets the requirements in the above paragraph to obtain a construction and an operation permit, if, in the judgment of the Department, the NCWS cannot be adequately regulated through standardized specifications and conditions.


2. Public Water System Permit Application - A NCWS must use the public water system permitting process for any new system or modification to an existing system that requires treatment to meet a primary MCL or if the system proposes use of a spring or surface water source. The Public Water Supply Manual, Part II – Community System Design Standards, lays out the permit application requirements. The NCWS is required to adhere to the NCWS Standards as outlined in the Public Water Supply Manual, Part IV – Noncommunity System Design Standards.