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DW Engineering Review | Facilities Review Application

Engineering Review

Facilities Review Application

Revised On: April 5, 2023 - 11:10 a.m.

Approval to Construct

An Approval to Construct (ATC) is a certificate issued by ADEQ or a delegated authority that allows an applicant to construct, modify, or make an alteration that will affect the treatment, capacity, water quality, flow, distribution or operational performance of a public water system.

The primary components necessary for an ATC application are:

  • ATC Application
  • Fee | View Fees >
  • Construction Plans/Drawings
  • Design Report
  • New Source Analysis (for new well or new source only)
  • Notice of Intent to drill (for new well only)
  • Water Service Agreement (if water source is provided by someone other than applicant) | View/Download >
  • ATC Application Form | View/Download >

ATC Design Report and Construction Drawing Examples

ADEQ created examples of a design report and construction drawings for use as a guidance document when filling out your ATC Application. Other agencies, cities, counties, contractors, developers, and other entities may require different or additional criteria and should be referenced accordingly.

The following examples show the minimum criteria needed for submittal to ADEQ:

Approval of Construction

An Approval of Construction (AOC) is a certificate issued by ADEQ or a delegated authority that allows an applicant to operate a public water distribution system after construction and final testing have been completed. A professional engineer registered in Arizona must complete a final inspection and submit a Certificate of Completion to confirm that the construction conforms to approved plans. 

The primary components necessary for an AOC application are:

  • As-Built Plans
  • Pressure/Leakage Testing Results
  • Disinfection Testing Results
  • Bacteriological Testing Results
  • Operations and Maintenance Manual (new treatment only)
  • AOC Application Form | View/Download >

Point of Use/Point of Entry Treatment

ADEQ safe drinking water rules allow public water systems to employ point-of-use (POU) or point-of-entry (POE) treatment devices as a means for compliance with drinking water maximum contaminant levels (MCL). Typically POU devices are designed to treat the water being used for drinking and cooking purposes and are installed at a single tap or kitchen sink. POE devices treat all the water coming into a home or building. Whereas, a centralized treatment system treats all of the water produced by the public water system. Since only 1 to 3 percent of water entering a home is used for direct consumption, a POU or POE compliance program can result in significant cost savings and be an attractive compliance option for many small water systems.

The Arizona POE and POU Treatment Devices Compliance Program Guidance provides an overview of the POE/POU compliance program including the minimum criteria and procedures1View/Download >

To apply for permitting of POU/POE treatment devices, use the ATC/AOC applications.

Point of Use (POU)/Point of Entry (POE) Templates & Forms | View/Download >

4-Log Removal Review

The Groundwater Rule provides increased protection against microbial pathogens in public water systems that use groundwater. Instead of requiring disinfection for all groundwater systems, a system can conduct triggered source water monitoring or compliance monitoring with 4-log removal. Triggered source water monitoring requires additional sampling and/or corrective action if a sample is positive for total coliform. Compliance monitoring requires a system to show they are providing consistent treatment by providing at least 99.99 percent (4-log) treatment of viruses (using inactivation, removal, or a state-approved combination of inactivation and removal) of all of their groundwater. In order to receive 4-Log Removal of Viruses credit, each system’s processes will need to be reviewed and approved by ADEQ. In order for a public water system to receive this approval, each system will need to submit an application form and required information.

4-Log Application Form | View/Download >

Design Standards

Several material, construction and testing standards are referenced by rule for drinking water systems. Commonly utilized standards referenced by rule include:

  • Engineering Bulletin 8 — Disinfection of Water Systems | View/Download >
  • Engineering Bulletin 10 — Guidelines for the Construction of Water Systems | View/Download >

Other system designs may be approved if the applicant can demonstrate that the system functions properly and may be operated reliably in compliance with Arizona Administrative Code (A.A.C.) Title 18, Chapter 5. Some standards may be from:

  • Maricopa Association of Governments (MAG): Standard Specifications & Details Committee | View Website >
  • Pima County and City of Tucson: Standard Specifications and Standard Details for Public Improvements | View Website >
  • American Society for Testing and Materials (ASTM) International | View Website >
  • American Water Works Association (AWWA) | View Website >
  • National Sanitation Foundation (NSF) | View Website >
  • ADEQ Point of Use Guidance Document | View/Download >


View our list of frequently asked questions and answers | View >

1Established by the Arizona Administrative Code (A.A.C.) R18-4-2181 and R18-4-1032 (40 Code of Federal Regulations (CFR) 142.62(h))