The International Association of Plumbing and Mechanical Officials (IAPMO) recently completed its technical committee meetings for the development of the 2021 editions of the Uniform Plumbing Code (UPC) and Uniform Mechanical Code (UMC). The UPC and UMC code development process is designed to follow the procedural requirements of the American National Standards Institute (ANSI) for development of an American national standard.

During the April 29-May 2, 2019, meetings at the Sheraton Denver Downtown Hotel, the plumbing and mechanical technical committees met and held hearings to vote on a total of 265 code-change proposals to amend the 2018 editions of the uniform codes.

Many of the code-change topics that generated debate were similar to the code changes submitted to the other model codes. This is because many of the people who develop code changes for use across the entire country and internationally submit the code change proposals to all of the model codes. The hope is that enforcement will be consistent everywhere. 

During the hearings, it is common for the code committees to modify the proposed code changes, which can lead to slight differences in code language from one model code to the next. During my reporting on the code changes to the international codes, I covered many of these code-change topics in previous columns, so I will limit discussions on those issues to save print space; however, there are some comments that are warranted in a few cases. 

This column will mostly be a simple reporting of the code changes from the 2018 code edition to the 2021 edition of the UPC. The most popular topics included rehabilitation of existing building sewers with slip-linings, and language related to limiting Legionella bacteria growth in plumbing systems. There were also code changes addressing drinking water treatment units, and new standards for a type of water heaters with temperature-limiting controls or devices.

During the UPC code hearings, it was apparent many of the code changes heard by the UPC Technical Committee were changes related to monitoring and control of Legionellabacteria growth in plumbing systems. 

The UPC Technical Committee was struggling with understanding many of the code changes related to the control and monitoring of conditions in the plumbing system that would limit or control Legionella bacteria growth. This is because the code hearings only allow about 2 minutes of testimony to go along with a code change proposal. 

The committee called for a Legionella Task Group to discuss the many code changes that were submitted dealing with the Legionella issue and changes that could be brought back in a comment for the final round of code hearings. Of course, the committee had to start with one of the code changes that had been rejected and try to fix it and present it for the next round of code hearings. 

The revised code change they selected continued using many made-up terms and temperatures for those terms that are in direct conflict with other ANSI standards. For example: one of the terms is “tepid water,” which has a temperature range differing from the temperature range of tepid water that is published in the ANSI standard for emergency fixtures. This creates a direct conflict between standards and promotes one plumbing term meaning two different temperatures. 

The UPC Technical Committee approved a reworded version of the code change, which was submitted as a public comment by the task group. It resulted in a proposed new Appendix N, titled, “Impact of Water Temperature on the Potential for Scalding and Legionella Growth.” 

Although there are many issues with the language which creates conflicts with other ANSI publications, the UPC Technical Committee voted to put the revised code language as the new Appendix N; they can try to fix the language in future editions of the Uniform Plumbing Code. 

Uniform Plumbing Code — Development Timeline

Task                                                                                  Date

Deadline for Submission of Proposals                              Jan. 4, 2021

Distribute Proposals to Committee (ROP Monograph)     April 1, 2021

UPC Tech Comm Meetings (Anaheim, Calif.)                   May 3-5, 2021 

UMC Tech Comm Meetings (Anaheim)                             May 6-7, 2021

Initial Ballots to Technical Committee                                June 4, 2021

Circulation of Comments on Ballots                                   June 18, 2021

Final Closing Date for Ballots                                             July 2, 2021

Technical Correlating Committee Meeting                          July 13, 2021

Distribution of Report on Proposals (ROP)                         Sept. 3, 2021

Call for Comments                                                              Sept. 3, 2021

IAPMO Assembly Consideration Session (San Antonio)    Sept. 28, 2021

Deadline for Submission of Comments                               Jan. 4, 2022

Distribute Comments to Committee (ROC Monograph)      March 30, 2022

Technical Committee Meetings                                            May 2-5, 2022

Initial Ballots to Technical Committee                                  May 16, 2022

UMC Code Changes

The UMC Technical Committee acted on 126 public comments. New refrigerants classified as A2L, which are mildly flammable refrigerants, are being used to phase out older refrigerants. The newer refrigerants have a lower global-warming potential number. The typical halogenated refrigerants, when released, contribute to the hole in the ozone and global warming. 

Other mechanical code changes addressing control systems and duct systems were hotly debated, with numerous A2L refrigerant comments submitted. The UMC Technical Committee expressed concern about the amount of research still needed for A2L refrigerant systems. Other topics discussed included automatic makeup water supply fill devices for hydronic systems, type II exhaust hoods, and indoor environmental air quality. 

The UMC Technical Committee commissioned a Legionella Task Group be formed to address exposure risk to the public from mechanical equipment. This task group will tackle the issue of control and intervention of Legionella associated with mechanical systems.

IAPMO met again for the final round of face-to-face code hearings at its annual education and business conference Sept. 22-26, 2019, in Reno, Nev., to allow anyone to comment on the proposed changes to the codes. IAPMO urges its members and other interested parties to get involved in the code development process to ensure effectiveness in preserving the public health, safety and welfare.

This is the first of a series of columns covering the code changes from the 2018 to the 2021 Uniform Plumbing Code changes. The following is my summary of the significant code changes that were approved during the code hearings. These code changes will appear in the 2021 edition of the UPC, which will soon be published and available for jurisdictions to consider for adoption.

 I recommend you refer to the 2021 Uniform Plumbing Code for the final version of any code changes reported on here. The proposed new code language is underlined. The text proposed to be deleted is stricken thru. The proposed changes are followed by the proponent’s published reason statements, and occasionally by my comments when noted.

Code Change: 2021 UPC Code, Chapter 2, Definitions Section 206.0 - D -, Section 309.6

Add new definition as follows:

206.0 - D - 

Dead Leg. A section of potable water pipe which contains water that has no flow or does not circulate.

309.0 Workmanship.

Add new text as follows:

309.6 Dead Legs. Dead legs shall have a method of flushing.

Proponent’s substantiation: Dead legs are currently silent in the code and should be addressed to avoid the growth of bacteria in water supply systems.

Code Change: 2021 UPC Code, Chapter 2, Definitions Section 207.0 – E –

Add new definition: 

Expansion Tank. A vessel used to protect potable water systems from excessive pressure.

Proponent’s substantiation: The term “expansion tank” is used throughout the code and the definition is necessary for the enforcement of the purposes.

Code Change: 2021 UPC Code, Chapter 2, Section 205

Remove text as follows:

205.0 -C-

Critical Care Area. A room or space in which failure of equipment or a system is likely to cause major injury or death to patients or caregivers (Category 1). [NFPA 99:3.3.28] 

Proponent’s substantiation: The definition for "Critical Care Area" should be removed as it is no longer referenced in the UPC or NFPA 99. The sections have been revised to correlate with NFPA 99-2018 (latest version) in accordance with IAPMO’s Regulations Governing Committee Projects (Extract Guidelines).

Code Change: 2021 UPC Code, Chapter 2, Section 205

Add new definition: 

205.0 - C -

Commercial Modular System. A drinking water treatment unit system consisting of multiple components attached to a manifold, produced specifically for food service applications, and not intended for use in residential applications.

My comments: The above text was added as part of a code change on drinking water treatment units where the term “Commercial Modular Units” was used.

Code Change: 2021 UPC Code, Chapter 2, Section 209

Revise text as follows:

214.0 209.0 - L G-

General Anesthesia and Levels of Sedation/Analgesia.

Deep Sedation/Analgesia. A drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. The ability to independently maintain ventilatory function may be impaired. Patients may require assistance in maintaining a patent airway, and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained. [NFPA 99: 3.3.61.23.3.66.2]

Proponent’s substantiation: The above sections have been revised to correlate with NFPA 99-2018 (latest version) in accordance with IAPMO’s Regulations Governing Committee Projects (Extract Guidelines).

Code Change: 2021 UPC Code, Chapter 2, Sections 210, 214, 215

Revise text as follows:

209.0 210.0 - G H-

Health Care Facility's Governing Body. The person or persons who have the overall legal responsibility for the operation of a health care facility. [NFPA 99: 3.3.62 3.3.72]

Add new text as follows:

214.0 - L -

Low-Pressure Water Dispenser. A terminal fitting located downstream of a pressure reducing valve that dispenses drinking hot water above 71°C (160°F) or cold water or both at a pressure of 105 kPa (15 psi) or less.

Revise text as follows:

215.0 - M - 

Medical Gas. A patient medical gas or medical support gas. (See also Patient Medical Gas and Medical Support Gas.) [NFPA 99: 3.3.93 3.3.99]

Proponent’s substantiation: The above sections has been revised to correlate with NFPA 99-2018 (latest version) in accordance with IAPMO’s Regulations Governing Committee Projects (Extract Guidelines).

Code Change: 2021 UPC Code, Chapter 2, Section 218

Add new text as follows:

218.0 - P -

Point-of-Entry, Water Treatment Unit. A device serving the water distribution system of a building for the purposes of altering, modifying, adding, or removing minerals, chemicals, contaminants, and suspended solids in the water.

Point-of-Use, Water Treatment Unit. A device serving a single atmospheric outlet such as a faucet for the purposes of altering, modifying, adding, or removing any minerals, chemicals, contaminants, and suspended solids in water.

Proponent’s substantiation: Water-conditioning devices and water-treatment devices are not appurtenances, appliances, fixtures or other types of products as in the plumbing code. It is important to define a “water conditioning or treatment” device, “point-of-use” and “point-of-entry” water conditioning or treatment devices when referring to these products. 

These are general terms consistent with what is used in the industry today and will harmonize with the current terms’ referenced standards for water treatment devices.

Code Change: 2021 UPC Code, Chapter 4, Sections 407, 408

Revise as follows:

407.3 Limitation of Hot Water Temperature for Public Lavatories. Hot water delivered from public-use lavatories shall be limited to a maximum temperature of 120°F (49°C) by a device that complies with ASSE 1070/ASME A112.1070/CSA B125.70. The water heater thermostat shall not be considered a control for meeting this provision. The maximum temperature shall be regulated by one of following means:

(1) A limiting device conforming to either ASSE 1070/ASME A112.1070/CSA B125.70.

(2) A Water Heater conforming to ASSE 1084.

408.3 Individual Shower and Tub-Shower Combination Control Valves. Showers and tub-shower combinations shall be provided with individual control valves of the pressure balance, thermostatic, or combination pressure balance/thermostatic mixing valve type that provide scald and thermal shock protection for the rated flow rate of the installed showerhead. These valves shall be installed at the point of use and comply with ASSE 1016/ASME A112.1016/CSA B125.16 or ASME A112.18.1/CSA B125.1.

Handle position, stop or temperature limiting control shall be provided on shower and tub-shower combination valves and shall be adjusted per the manufacturer’s instructions to deliver maximum mixed water setting of 120°F (49°C). Water heater thermostats shall not be considered a suitable control for meeting this provision.

408.3.1 Gang Showers. Where gang showers are sup-plied with a single temperature-controlled water supply pipe, it shall be controlled by a mixing valve that com-plies with ASSE 1069.

408.3.2 Temperature Limiting. The maximum water temperature discharging from an individual showerhead shall be limited to 120°F (49°C) by one of the following methods:

A shower or tub/shower combination valve conforming to ASSE 1016/ASME A112.1016/CSA B125.16 where either:

The valve is field-adjusted to the required maximum temperature, or

The handle position, stop, or temperature limiting control is set in accordance with the manufacturer's instructions to the required maximum temperature;

For gang showers supplied by a single water supply pipe, a mixing valve that conforms to ASSE 1069 that is field-adjusted to the required maximum temperature;

A limiting device conforming to either ASSE 1070/ASME A112.1070/CSA B125.70 or CSA B125.3;

(4) A water heater conforming to ASSE 1084;

A temperature actuated flow reduction device conforming to ASSE 1062.

Proponent’s substantiation: There are methods other than handle limit stop and ASSE 1070/ASME A112.1070/CSA B125.70 devices that can be used to limit the maximum water temperature to 120 F. All these other methods are equally effective in preventing scalding in a shower, bathtub, bidet and handwashing facility. 

Three new ASSE standards regulate water heaters to be equivalent to various temperature-limiting and thermostatic mixing valves. ASSE 1082 requires the water heater to be equivalent to an ASSE 1017 valve. Similarly, ASSE 1085 requires the water heater to be equivalent to ASSE 1070/ASME A112.1070/CSA B125.70 devices. 

For showers and gang showers, ASSE 1062 devices can be used to cut the flow pattern in a shower when the temperature reaches 115 F. This provides scald protection from upper temperatures and is used in conjunction with a compensating shower (balanced pressure or thermostatic mixing) valve. 

Finally, an ASSE 1017 valve can be used at the water heater to limit the upper temperature of the hot water. When installed, there is no need to adjust the handle limit stop since the hot water at the shower valve cannot exceed 120 F.

Proponent’s public comment #1 substantiation: When this code change was originally submitted, ASSE 1082 and ASSE 1084 were not yet completed. The standards have since been published as ANSI standards. The 2018 date has been added to the reference in Table 1701.1. 

I was asked to make one minor modification to the proposed change by striking reference to ASSE 1017 for bidets. That is the only modification to the original change being proposed. The reason for this modification is that ASSE 1017 does not regulate creep in a thermostatic mixing valve. A thermostatic mixing valve could allow the temperature to increase slightly during the use of the bidet. Creep does not occur in water heaters meeting the new standards listed. 

My comments: The ASSE code committee chair submitted a comment asking to retain the stricken language prohibiting the water heater thermostat from being used as the final control for complying with scald requirements at fixtures. That comment was rejected. The ASSE 1085 mentioned above was not developed to meet the requirements of ASSE 1017. 

The ASSE 1017 standard allows temperatures to fluctuate up to 7 degrees above and below the set point; there is a significant time delay before recording the temperature for conformance to the standard. This time delay was to allow larger valves that rely on slower-acting bi-metal coils or smaller paraffin-wax thermal motors on large valves time to sense the change in temperature and adjust for the outlet temperature. 

An ASSE 1085 water heater, it is supposed, was developed to be equivalent to the ASSE 1071 valve. Currently, the ASSE 1071 mixing valve device, developed for providing tepid water to emergency fixtures, must provide an internal cold water bypass in the event of a high temperature at the device outlet or in the event of a valve failure. I am not aware of any such requirement for a cold water bypass in the ASSE 1085 standard. 

For combination emergency fixtures, the devices must control the water temperature accurately at the flow rate of an eye wash operating by itself (4 gallons/minute) and at the combined flow rate when the eyewash and emergency shower are flowing (24 gpm). Also, it has been well-documented that the temperature serving emergency fixtures should not exceed 100 F because doctors have determined that flushing the eyes for 15 minutes at temperatures above 100 F can damage the eyes.

Code Change: 2021 UPC Code, Chapter 4, Section 417.6

Add new language as follows:

417.6 Low-Pressure Water Dispenser. Beverage faucets shall comply with ASME A112.18.1/CSA B125.1. Low-pressure water dispensers that dispense electrically heated or chilled water and have a reservoir vented to the atmosphere shall comply with ASSE 1023 and UL 399.

Proponent’s substantiation: Beverage faucets are currently in the scope of ASME A112.18.1. Those beverage faucets that have an integral reservoir of hot water vented to atmosphere generally are already in compliance with ASSE 1023.

Code Change: 2021 UPC Code, Chapter 6, Section 611

Revise as follows:

611.0 Drinking Water Treatment Units.

611.1 Application. Drinking water treatment units shall comply with the applicable referenced standards in Table 611.1. NSF 42. or NSF 53. Water softeners shall comply with NSF 44. Ultraviolet water treatment systems shall comply with NSF 55. Reverse osmosis drinking water treatment systems shall comply with NSF 58. Drinking water distillation systems shall comply with NSF 62.

611.1.1 Alkaline Water treatment. Alkaline water treatment devices shall comply with IAPMO IGC 322.

611.1.2 Scale Reduction Devices. Scale reduction devices shall comply with IAPMO Z601. 

TABLE 611.1 DRINKING WATER TREATMENT UNITS

APPLICATION	RESIDENTIAL		COMMERCIAL
	POINT-OF-USE	POINT OF ENTRY
	Commercial and Food Service Water Treatment Equipment Utilizing Drinking Water	Water Conditioning, Water Treatment
Aesthetic Contaminant Reduction (Filters)	NSF 42	NSF 42	ASSE 1087  And NSF 42*
Health Related Contaminant Reduction (Filters)	NSF 53	NSF 53	ASSE 1087 and  NSF 53*
Water Softener		NSF 44	ASSE 1087
Ultraviolet Water Treatment	NSF 55	NSF 55	ASSE 1087
Reverse Osmosis	NSF 58	NSF 61	ASSE 1087
Distillation	NSF 62	NSF 62	ASSE 1087

*Required for commercial modular Systems only

Code Change: 2021 UPC Code, Chapter 17 Referenced Standards, Table 1701.1

Revise text as follows:

TABLE 1701.1 REFERENCED STANDARDS

STANDARD NUMBER	STANDARD TITLE	APPLICATION	REFERENCED SECTIONS
ASSE 1087-2018	Commercial and Food Service Water Treatment Equipment Utilizing Drinking Water	Water Conditioning, Water Treatment	Table 611.1
NSF 42-2017	Drinking Water Treatment Units –Aesthetic Effects	Appliances	611.1 Table 611.1
NSF 44-2017	Residential Cation Exchange Water Softeners	Appliances	611.1 Table 611.1
NSF 53-2016	Drinking Water Treatment Units-Health Effects	Appliances	611.1 Table 611.1
NSF 55-2017	Ultraviolet Microbiological Water Treatment Systems	Appliances	611.1 Table 611.1
NSF 58-2017	Reverse Osmosis Drinking Water Treatment Systems	Appliances	611.1 611.2 Table 611.1
NSF 61-2017	Drinking Water System Components –Health Effects	Miscellaneous	415.1, 417.1, 604.1, 604.9, 606.1, 607.2, 608.2, 608.3, Table 611.1
NSF 62-2017	Drinking Water Distillation Systems	Appliances

Proponent’s substantiation: For decades the NSF/ANSI drinking water treatment unit standards have been the only standards referenced by the Uniform Plumbing Code covering both residential and commercial applications including food service. The NSF/ANSI standards address:

1. Material Safety — testing to ensure materials used are safe from a chemical extraction standpoint.

2. Structural integrity — testing systems for intended pressure applications.

3. Performance — verifying that the product reduces contaminants from the water as claimed.

While the NSF/ANSI standards cover most treatment applications, there are a few applications that fall outside their current scope. Large commercial water softeners are one of the most prevalent examples. 

ASSE promulgated a standard whose scope both overlaps some products covered by the NSF/ANSI standards and also covers some products outside the scope of the NSF/ANSI standards. The ASSE standard addresses:

1. Material safety by referencing NSF standards.

2. Structural integrity by referencing NSF standards or offering an alternative pathway.

If the UPC is to reference ASSE 1087, it is critical that the code is clear when NSF/ANSI standards are required, when ASSE 1087 is required and when both may be required. With the lack of performance criteria within ASSE 1087, public health concerns are not addressed from a treatment perspective. Therefore, it is critical that claims are verified whenever appropriate. 

In order to get a clearer picture of when certain standards apply, it is necessary to distinguish between residential and commercial, and to define point-of-use (POU), point-of-entry (POE) and commercial modular applications. POU and POE are differentiated for residential applications because of slight differences in standards for water softeners and reverse osmosis. 

The scope of NSF/ANSI 44 only addresses residential water softeners for POE applications, whereas the scope for NSF/ANSI 58 only addresses POU applications. Therefore, all POE reverse osmosis units conform to NSF/ANSI 61. 

POU and POE is not differentiated in the commercial column because it does not drive a difference in standards required. Commercial modular systems are basically treatment devices that are connected by a manifold for use in food service applications. It is important that these products be required to meet both the NSF and ASSE standards so that all critical aspects (such as performance claims) are addressed.

ASSE and NSF collaborated on the creation of this table.

This has been part 1 of a series covering significant code changes from the 2018 to the 2021 edition of the Uniform Plumbing Code. I will continue reporting on the significant changes to the UPC next month.