Subscribe to our newsletters & stay updated
The International Association of Plumbing & Mechanical Officials (IAPMO) met May 15-18 in Ontario, California, to hold the first round of technical committee meetings for the development of the 2021 editions of the Uniform Plumbing Code (UPC) and Uniform Mechanical Code (UMC). The committees acted on nearly 450 proposed amendments to the 2018 editions of the uniform codes.
The UPC committee acted on 247 code change proposals. Topics generating the most debate included rehabilitation of existing building sewers with slip-lining products, Legionella risks and circuit venting methods, where the technical committee discussed potential language to clarify sizing guidance and what combination of fixtures are acceptable.
There was a lot of emotional testimony given on several code changes related to the control of Legionnaires disease in water systems. The technical committee requested that a Legionella Task Group be formed to address mitigation of the waterborne bacteria, pathogens and associated scald risk provisions in the appendices of the UPC.
This task group’s scope includes reviewing and developing recommendations, if appropriate, on item No. 228 of the UPC to determine methods available to address the health and safety impacts of water temperature on Legionella and scald risks. Its recommendations will be forwarded to the UPC technical committee for consideration.
A Report on Proposals (ROP) will be created from balloted actions and distributed to committee members on or after Aug. 20, 2018. All suggested code amendments, additions and deletions published in the ROP will be available for public review on the IAPMO website. The next round of technical committee meetings will be held at IAPMO’s annual Education and Business Conference, Oct. 2, 2018 at the Sheraton Downtown Hotel in Philadelphia.
The May UPC technical committee meetings overlapped the World Plumbing Council meeting, also hosted by IAPMO at the same hotel, which allowed many plumbing officials from around the world to drop in on the code hearings.
Here are a few of the highlights from the UPC hearings:
There was a proposed code change to add a definition for a dead leg and a companion code change with a requirement that dead legs have a means for flushing the water in the them. This code change was well-received because of the increased awareness of Legionnaires’ disease or legionellosis associated with building water systems and the understanding that Legionella bacteria is more likely to grow in stagnant water.
This code change proposal was successful and if it makes it through the next round of code hearings, it will require all dead legs to be kept to a minimum. There was also a requirement for a drain valve or fixture that is located so as to allow for periodic flushing of the dead leg.
There were a couple of code change proposals to change the definition of “public or private use” requirements for public lavatories in hospitals or health care facilities and there was a companion change to remove the requirement for hot water to lavatories use for hand washing in public buildings. The companion proposal to the definition change was to remove hot water requirements at hand-washing facilities to address a concern that hot water causes Legionella bacteria.
I am sure the majority of plumbing installations in the country have cold water that gets well below 60 F during winter months. Water that cold will be very uncomfortable and it would discourage proper washing times. I conducted testing in a high-rise building where, during the winter months, cold water temperatures were very cold. I used a digital multimeter to verify temperatures at a lavatory to determine the minimum temperature that would be suitable to promote proper handwashing. I found that 60 F was very uncomfortable and caused joint pain and discomfort, which would discourage thorough washing for most people.
When the water temperature got up to around 72 F, it still felt cold to the touch. I thought if I had to wash my hands I could do it in 72 F water without much discomfort. Based on this research, I would not be in favor of any code change to eliminate the requirement for hot water for handwashing. The majority of locations, even in the southern states, can have very cold water in winter months, sometimes below 60 F. Water below 72 F is not conducive to washing long enough to remove bacteria, grease and oils on your hands for proper hygiene.
The solution is not to eliminate the hot water system, but to design the system so that water is hot enough to prevent Legionella bacteria growth and then reduce to a safe temperature for the intended use at each fixture with appropriate temperature controls. Hot or tempered water should be available from the fixture within a few seconds of turning on a faucet.
Each code change cycle seems to bring about more of the same water conservation “limbo” contest. How low can we go with water conservation efforts with no research as to the effects that the flow reductions will have on the drain line transport and water quality, or the ability of a device to provide adequate temperature control at reduced flow rates?
The reduced flows have been contributing to aging water or stagnant water in water mains. Aging or stagnant water occurs when water sits in a pipe long enough for the water treatment chemicals to dissipate to levels that are ineffective at fighting bacteria. The continued reductions in flow at fixtures have caused water utilities to scramble to address water-quality issues in the distribution systems.
There are primarily three chlorine-based water treatment chemicals; chlorine is by far the most popular and the cheapest water treatment chemical used. When chlorine residuals are dissipating to undetectable levels at the ends on the utility distribution systems, levels that will not control bacteria growth, another chemical used by water utilities is monochloramine. The third water treatment chemical is chlorine dioxide, which is effective for a brief period. Because chlorine dioxide is expensive, difficult to handle in a gaseous state and reacts and dissipates so fast, it is not commonly used for utility water treatment.
As a former member of a water utility, I am aware of many issues water utilities face with respect to water treatment, providing safe drinking water and the difficulty maintaining water treatment chemical residuals at ends of the long rural water mains in a utility system. Utilities often try to periodically flush fresh water into the system to help raise the water treatment chemical residuals by either flushing fire hydrants or adding secondary water treatment booster stations, similar to pressure-boosting stations.
More research needs to be done on the effects of water quality or aging water. Water flows are being reduced so low, some water utilities are having to flush hydrants near the ends of their utility distribution systems in order to comply with the Safe Drinking Water Act. Other water departments have resorted to using monochloramines, which are less effective than chlorine and slower to oxidize, resulting in a measurable water treatment chemical residual at the end of a distribution system. It is not as effective at addressing common disruptions in the system that dislodge large amounts of water main scale, sediment and biofilm.
I once compared the effectiveness of chlorine versus monochloramines for fighting bacteria in water mains. Using chlorine is like using an assault rifle against a charging army of Legionella bacteria during a turbid water event.
Using monochloramines in a water utility distribution system is like using a bow and arrow in the same situation. The slower oxidizing chemical will be overrun by the army and allow a significant number of bacteria to enter the distribution piping system.
During the UPC hearings, there was a series of proposed code changes to accept several standards on water heater temperature control that have not been finalized and published yet. The standards proposed were ASSE 1082, ASSE 1084 and ASSE 1085.
ASSE 1082 is intended to be equivalent to the temperature-actuated mixing valve requirements in ASSE 1017 for hot water distribution systems. ASSE 1084 is reported to be a water heater temperature limiting standard intended to have requirements similar to those contained in ASSE 1070 for temperature limiting devices. ASSE 1085 is reported to be a standard similar to ASSE 1071, temperature limiting devices for emergency fixtures. The draft I saw of this standard was very similar to the ASSE 1082 standard and did not adequately address temperature limiting tests or a cold-water by-pass that would make it equal to the ASSE 1071 standard.
The American Society of Sanitary Engineering International (ASSE) has several manufacturers and their consultants hastily trying to draft these standards before the final round of code hearings this fall. Code changes have been submitted to accept these standards; none of them were completed as of this writing and one of them did not make a final draft to review.
Manufacturers are in the process of developing several of these new water heater temperature control standards up against code hearing deadlines. This is a recipe for sloppy standard development when standards are hastily assembled against a deadline. These code changes were turned down because there was not a final published copy of the standard submitted for the committee to review.
These standards were first proposed when a tankless water heater manufacturer approached me as a member of the ASSE product standards committee and asked if its tankless electric water heater, which has temperature-limiting control capability, could be tested for compliance to the ASSE 1070 standard for temperature-limiting devices.
The code requires temperature-limiting devices to deliver tempered water to handwashing facilities in order to meet the scald prevention code requirements for a temperature-limiting device (mixing valve) conforming to ASSE 1070 to limit the temperature at these fixtures. I told the manufacturer I didn’t think it would be possible because ASSE 1070 is a mixing valve standard for mixing hot and cold water. What he had was a water heater that heated cold water and had temperature-limiting controls.
The manufacturer pointed out that the ASSE 1070 standard is titled as a “temperature-limiting device” standard and the company’s tankless heater had temperature-limiting controls and thus was a temperature-limiting device. I told the manufacturer I was not sure that it would be acceptable but it might be worth it to ask the ASSE product standards committee if it would accept a modified test to the ASSE 1070 standard.
The manufacturer asked for an interpretation from the committee at an ASSE product standards committee meeting. He was told that a new product standard would need to be developed for tankless water heaters. Upon the manufacturer making a request to ASSE that a standard be developed, ASSE notified other water heater manufacturers, many of whom had little experience with codes, standards or temperature-limiting devices and how they were used in hot water system designs.
At subsequent ASSE standards meetings, many water heater manufacturers showed up and it seemed like everyone wanted a temperature control standard for their products. The majority did not care about the point-of-use temperature-limiting application because it did not fit into their product line. As of this writing, the standards were still in the draft stage and may require more review to assure they match the corresponding mixing valve performance requirements.
A couple of years ago, The American Society of Mechanical Engineers (ASME) shocked the plumbing industry with an announcement it was going to focus on other emerging industries and technologies. It planned to transfer the administration and secretariat of the plumbing standards to the International Code Council (ICC) and the Canadian Standards Association (CSA).
Then, in a turn of events this spring, the ASME A112 committee on plumbing materials and equipment received a notice that ICC and CSA would not be taking over the ASME A112 standards. Attorneys and officials from all three organizations have been meeting on and off for a couple of years trying to work out a smooth transition for turning over the standards. After meeting with the parties and trying to work out a transfer of the standards to other organizations, ASME has decided to continue to sponsor the plumbing products and materials standards.
The 2018 ASHRAE meeting was held June 23-27, 2018, in Houston. The five-day event included eight conference tracks and one mini-track – HVACR systems and equipment, fundamentals and applications, district energy and cogeneration plants, HVAC and resiliency, modern residential building in hot and humid climates, professional skills, HVACR analytics, HVACR controls and a research summit. In addition, many technical committee meetings were held for various standards and guidelines.
The next ASHRAE meeting is the 2019 winter conference and AHR Expo, Jan. 12-14 in Atlanta. View more information at www.ashrae.org/conferences/winter-conference.
Ron George, CPD, is president of Plumb-Tech Design & Consulting Services LLC. Visit Plumb-TechLLC.com.