The quality of drinking water shall meet drinking water quality standards.
The central competent authority shall determine the drinking water quality standards according to the foregoing paragraphs.

Public or private premises that provide stationary continuous water supply equipment for public drinking shall perform sampling and testing of water quality conditions and keep maintenance records for future reference. The central competent authority shall determine regulations for water quality test items, frequency, maintenance records, posting, validity period, methods for sample testing of equipment and other binding matters.
Sampling, inspection and analysis of water quality conditions mentioned in the preceding paragraph shall be conducted by an environmental analysis laboratory that has obtained a certification issued by the central competent authority.

Analysis laboratories shall obtain certification issued by the central competent authority before they may perform analysis in this Act.
The central competent authority shall determine management regulations for the required condition; facilities; application, review, issuance, replacement, revocation, cancellation, suspension of business, resumption of business, checking and evaluation of permits ; and other binding matters for analysis laboratories in the foregoing paragraph.
The central competent authority shall determine the testing methods and quality control matters for drinking water source quality, drinking water quality and drinking water treatment chemicals.

Chemicals used for drinking water quality treatment shall be limited to those officially announced by the central competent authority.
Water supply entities may apply to the central competent authority to officially announce an unlisted Chemicals used for drinking water treatment. The central competent authority shall determine the regulations governing application qualifications, documentation that shall be attached, procedures, approval conditions, rejection, corrections, and other binding matters.

Competent authorities at all levels shall select locations, conduct regular sampling and testing, compile and analyze data, and take appropriate measures based on the testing results. A competent authority shall officially announce promptly a prohibition on the consumption of drinking water for which it has been proven there is a concern about the endangerment of human health.
Special municipality, county and city competent authorities shall report the sampling locations, testing results and adopted measures in the foregoing paragraph to the central competent authority.

When a natural disaster or other force majeure causes drinking water source quality to deteriorate, affected water supply entities for tap water, simple tap water, or community-installed public water supplies shall adopt contingency measures and strengthen drinking water quality testing promptly after the incident occurs. Affected water supply entities shall also promptly notify the public regarding water quality conditions and response measures via newspaper, television, radio, billboards, posted official announcements or other methods.

Competent authorities at all levels may send personnel to enter public and private premises bearing documents verifying their duties or with other identification sufficiently indicating they are authorized to inspect drinking water source quality, drinking water quality, stationary continuous water supply equipment, drinking water treatment chemicals, or seek relevant samples or data. Evasion, obstruction, or refusal by owners, users, or managers of public or private premises is prohibited.

For circumstances in which the use of a water body as a drinking water source or for drinking water is prohibited pursuant to Article 21 or Article 24, once the water intake organization or water supplier addresses the reason for placing a prohibition on the water body, a non-subordinate environmental analysis laboratory that has received a permit from the central competent authority shall carry out sampling of the water body that originally failed to meet water quality standards. The water body may resume serving as a drinking water source or as drinking water after the sample has been sent for testing and an environmental analysis report showing adherence to standards has been submitted to and approved by the organization that handles the review of the matter.