ANSI AWWA C654-21 PDF

Full title and description

ANSI/AWWA C654-21 — Disinfection of Wells. This American Water Works Association (AWWA) standard specifies minimum requirements and procedures for disinfecting wells used for potable water service, including methods for chlorination, bacteriological testing, and corrective actions following construction, servicing, maintenance, or any event that may contaminate a well.

Abstract

This standard provides step-by-step procedures for applying disinfectants (commonly chlorine solutions) to wells and associated appurtenances (gravel or filter pack, well casing, screen, open-borehole intake, pump, and piping), specifies bacteriological sampling and testing requirements to verify successful disinfection, and describes actions to correct contamination. It establishes minimum concentrations, contact times, sampling frequency, and verification criteria for returning a well to potable service.

General information

• Status: Active / Current AWWA standard.
• Publication date: October 25, 2021 (2021 revision).
• Publisher: American Water Works Association (AWWA); ANSI-accredited.
• ICS / categories: Water quality / Disinfection of facilities (ICS references commonly associated with water quality and potable-water standards).
• Edition / version: 2021 edition (designated C654-21).
• Number of pages: Approximately 24–28 pages (standard PDF/print length varies by distributor).

Scope

The scope covers disinfection, bacteriological testing, and contamination-prevention procedures for new and existing individual, private, and community wells used for potable water. Procedures include preparation, application of disinfectant to the well column and related components, recommended disinfectant concentrations and contact times, sampling for coliforms and other bacteriological indicators, and verification steps before placing the well back into service. The standard applies to gravel-pack wells, screened wells, bedrock (open‑borehole) intakes, casings, pumps, and appurtenant piping.

Key topics and requirements

• Definitions and general requirements for well disinfection and safety.
• Recommended chemical disinfectants and preparation of chlorine solutions (including example concentrations such as 50 mg/L and 100 mg/L guidance where applicable).
• Procedures for applying disinfectant to gravel pack, casing, screen/open borehole, pump, and appurtenant piping in logical implementation sequence.
• Specified contact times and procedures for flushing and sampling after treatment.
• Bacteriological sampling protocols, acceptance criteria, and re-treatment thresholds.
• Verification, recordkeeping, corrective actions, and precautions to protect personnel and the environment (including dechlorination/discharge considerations where needed).

Typical use and users

Utility operators, well drillers, consulting hydrogeologists, public‑health and environmental compliance staff, water system owners/operators, and contractors performing well construction, repair, rehabilitation, or maintenance use this standard to ensure wells are made safe for potable service following activities that risk contamination. Regulators and permitting authorities reference it when specifying minimum disinfection and testing requirements.

Related standards

Commonly referenced alongside: AWWA C651 (Disinfecting Water Mains), C652 (Disinfection of Water‑Storage Facilities), C653 (Disinfection of Water Treatment Plants), C655 (Field Dechlorination), AWWA A100 (Water Wells), and applicable NSF/ANSI standards for treatment chemicals and materials (for example NSF/ANSI 60 and 61). These documents together address disinfection practices across distribution, storage, treatment, and well construction.

Keywords

well disinfection, shock chlorination, bacteriological testing, potable water wells, well rehabilitation, chlorine contact time, sampling protocol, gravel pack, well casing, AWWA C654-21

FAQ

Q: What is this standard?

A: ANSI/AWWA C654-21 is the AWWA standard titled "Disinfection of Wells" that establishes minimum procedures and verification steps for disinfecting wells used for potable water service.

Q: What does it cover?

A: It covers selection and preparation of disinfectants, application procedures for wells and associated components (gravel pack, casing, screen/open borehole, pump, piping), bacteriological sampling and testing, contact times, verification criteria, and corrective actions to restore potable water quality.

Q: Who typically uses it?

A: Water system operators, well drillers and contractors, consulting engineers and hydrogeologists, public-health officials, and regulators use the standard to ensure safe and consistent disinfection practices for potable wells.

Q: Is it current or superseded?

A: The 2021 edition (C654-21) is the current revision that supersedes the 2013 edition (C654-13). Users should confirm they are using the 2021 edition for the latest requirements and guidance.

Q: Is it part of a series?

A: Yes — C654 is part of AWWA's cluster of disinfection and related standards (for mains, storage facilities, treatment plants, and field dechlorination) and is often used together with other AWWA standards and applicable NSF/ANSI chemical and materials standards.

Q: What are the key keywords?

A: Well disinfection, shock chlorination, bacteriological sampling, potable water, chlorine concentration, contact time, verification, AWWA C654-21.