Alternate water systems take center stage.

Photo credit: Uponor

A new edition of the IAPMO Uniform Plumbing Code was recently issued with a date of 2012. This code, often referred to as the UPC, is typically considered a West Coast code. However, the UPC is used in other locations - Maine is the farthest East Coast state that has adopted the UPC.

In the new UPC, one chapter was added that every jurisdiction may be taking a look at -  Chapter 16, “Alternate Water Sources for Nonpotable Applications.” While that is a mouthful, it is basically green plumbing systems using nonpotable water. The nonpotable water includes graywater, rainwater and reclaimed water, to name a few.

You may not be interested in alternate water sources, but the rest of the world is. This is the first comprehensive chapter on requirements applicable to all types of nonpotable water. While not trying to demean the rest of the code, this is one of the finest chapters ever published on alternate water sources.

All the different types of alternate water are clearly described. The chapter then explains where each water source may be used. An example would be graywater that is untreated can only be used for subsurface irrigation. This would include the discharge to a mulch basin, which also is described in the chapter. If graywater is treated, it may be used for flushing water closets and urinals.

While requiring graywater to be treated sounds nice, the code requirements go into great detail regarding the treatment that is required. One of my favorite sections is the table listing the minimum testing, inspection and maintenance for any alternate water source, which has always been a bone of contention when using a nonpotable water source. With the requirements clearly spelled out, everyone can be on the same page.

Furthermore, building owners know up front what is required for an alternate water source. There are no surprises when they find out that the inspection and maintenance is ongoing and a very important part of being green. You just can’t build a plumbing system, call it green and walk away. Continuous monitoring and maintenance are required for alternate water systems.

Different labeling requirements depending on the type of alternate water source being used also are included. This makes it clear to future users or maintenance personnel what type of water is installed.

It should be noted the Plumbing-Heating-Cooling Contractors - National Association adopted these requirements in the 2012 edition of the National Standard Plumbing Code. Hence, jurisdictions using the NSPC will encounter parts of the UPC.

Other changes

The chapter on alternate water sources was coordinated with Chapter 6 on water supply and distribution. Other changes were made to Chapter 6 that will help plumbing contractors. It was clarified that polyethylene tube and PVC pipe may be used for cold water applications outside, underground and within the building. Neither material is approved for hot water applications.

Some of the joints and connection requirements were clarified. Push-fit fittings were added as acceptable fittings for joining various piping material including copper, CPVC and PEX. Basically, every viable piping material and joining method is approved for water distribution systems in the UPC.

In the venting requirements, some minor tinkering occurred in the horizontal wet vent section. On the West Coast, horizontal wet venting is still a relatively new concept. While horizontal wet venting has been used in other parts of the country for more than 80 years, it is still misunderstood in the West. IAPMO has formed a committee to try to straighten out the wet venting requirements. It is hoped that modifications will be forthcoming in the next edition for clearer and easier requirements to follow.

What is most notable in the drainage section is what did not change. There was an attempt to add PVC pipe made with recycled material. The recycled PVC is not from soda bottles or plastic that consumers recycle. The recycled PVC is from the manufacturing facility. Hence, it is considered clean PVC. While the code committee approved the recycled PVC, the IAPMO membership voted to reject the code committee’s approval. In the end, the rejection was upheld.

Contractors should realize that the rejection of the code change does not mean they cannot use the piping material. It simply means that to use recycled PVC, you must seek local approval for each project. This is currently allowed under Chapter 3 of the UPC. So, if you have a project where recycled PVC is specified, just apply for local approval to use the pipe. You also can get the project engineer to help obtain the local approval.

A new chapter was added to the UPC - Chapter 17, on rainwater catchment systems. While Chapter 16 applies to the use of alternate water sources, Chapter 17 regulates the system for collecting and storing rainwater.

Added to the appendix is a new chapter on using rainwater for potable applications. The requirements in the appendix dovetail with the requirements currently used on many Caribbean islands where they collect rainwater for drinking. This was added to the appendix so that a jurisdiction can decide whether to adopt the requirements.

If you are used to using the UPC, you will find a number of changes to the wording in various sections. This was an attempt to make the code more understandable and legally enforceable. I think the authors did a good job and you will find the UPC easier to use (if that is possible with a plumbing code).

You can obtain a copy of the new UPC by going to The UPC is available in soft cover, hard cover and electronic means. IAPMO also allows you to view the code electronically on its website. I find it easier to just buy a copy of the electronic code.