Plumbing

"Greening" your plumbing is an opportunity to realize important energy and water savings with efficiency investments that pay back rapidly.

Between well–known water conservation measures and new high–efficiency technologies there is a range of options from basic plumbing upgrades and renovations to new integrated systems that heavily reduce water consumption and recycle most or all water onsite.

1 Water-conserving fixtures
2 Water-saving appliances
3 Pipe insulation
3 Alternative technologies
3 Pre-plumb
3 Pipe materials

Integrated systems pay off not only in reduced water bills, but also in reduced installation costs as it can downsize boilers, pumps, and valves, and plumbing runs in a more efficient overall approach. Lastly, the health impacts of the materials commonly used in plumbing, and of water delivered to buildings, are areas where you can make contributions to your own health and the broader environment.

Goal: Save water and energy in plumbing systems

Water heating can account for up to 15% of commercial building fuel use, or $300 per year for a single–family home. Heating water more efficiently, and preventing that heat from being lost, represent opportunities to claim often overlooked savings: techniques include both familiar approaches, such as insulation, and innovative new technologies such as heat recovery devices. San Mateo County's water systems are expensive to maintain and to enlarge, and this expense is reflected in your monthly water bill. Water conservation doesn't have to mean washing dishes by hand, however — lots of new technologies simply use less water to deliver the same level of service we get from older, less efficient equipment.

area one

Use water–conserving plumbing fixtures

What is this?

Faucet and showerhead aerators, automated faucets and flush valves, waterless urinals, dual flush toilets, and pressure–assisted toilets are all available products that are reliable alternatives to older fixtures and use less water to perform the same functions.

Why do it?

The savings in water bills will often pay for water–conserving fixtures in short periods of time, and rebates are available for some conservation products. Also, plumbing fixtures that use less water often require smaller plumbing lines, or less plumbing, than conventional fixtures, making installation easier and less expensive.

How to do this?

System design in advance is always the best way to gain all the benefits of advanced performance. Ask about fixture water use and shop around for high–performance appliances if your supplier is not familiar with them or does not carry them.

Who does this?

Building owners, plumbing engineers, subcontractors.


area one

Use water–saving appliances and equipment

What is this?

Major appliances use major volumes of water. Look for water–efficient dishwashers and washing machines for your home, and in commercial buildings, also consider chiller units and cooling towers. Newer appliances can cut water use — and associated costs — dramatically. The more you use, the more you will save.

Why do it?

Horizontal–axis washing machines and high–efficiency dishwashers use 40% less water than conventional models. Efficient cooling equipment can save millions of gallons per year for commercial projects.

How to do this?

Water–efficient appliances are energy–efficient too, so look for the ENERGY STAR® label. For engineered equipment and larger systems, be sure to evaluate projected water consumption of proposed units and factor it into your decision–making.

Who does this?

Homeowners, mechanical engineers, equipment subcontractors.


area one

Insulate hot and cold water pipes

What is this?

A simple layer of pipe insulation prevents hot water from cooling off or cold water from heating up on its way to the tap.

Why do it?

This is one of the most cost–effective ways to save energy, where a very small investment can give back dollars every month. It will also keep hot water pipes hotter, shortening the waiting time for hot water to arrive at the tap.

How to do this?

Wrap pipes with wrap or tubular insulation, available at hardware stores for homeowners.

Who does this?

Homeowners, plumbers, facilities managers.


area one

Use heat recovery equipment, tankless water heaters and/or on–demand hot water circulation pumps

What is this?

Heat recovery transfers heat from draining water to hot water supply lines without mixing the two streams. Tankless water heaters only heat water when needed, eliminating stand–by losses. On–demand pumps get hot water to taps faster, reducing time and water spent waiting for water to heat up.

Why do it?

Drainwater heat recovery can reduce hot water use 50% or more, which can allow for smaller water heaters if designed accordingly. Tankless heaters can reduce energy use by 15% compared to storage heaters, and take up a fraction of the space. On–demand pumps cut time waiting for hot water 75% or more.

How to do this?

Design an efficient plumbing system for a new building by thinking through water needs, mechanical space needs, and fuel costs first. More efficient systems can create additional savings in smaller return plumbing runs or reduced appliance sizes. When renovating or replacing equipment, upgrade components to more efficient varieties.

Who does this?

Homeowners, plumbing engineers or subcontractors.


Waterless urinal trap image

New waterless urinal technology: In the waterless urinal trap, lighter–than water fluid seals behind draining waste, reducing water consumption to zero. Waterless urinals represent a major opportunity for water savings in commercial buildings, and can be cheaper to install as well.


area one

Pre–plumb for future graywater use for toilet flushing and landscape irrigation

What is this?

"Graywater" refers to wastewater from sinks, showers, and laundry — in distinction to "blackwater" from toilets and urinals. Because graywater is not as dirty as blackwater, it can be used for non–potable uses, such as flushing toilets or watering lawns, with relatively minor treatment. Current plumbing codes do not recognize this distinction, so most large–scale graywater installations may not be possible; however, adding a little extra plumbing that will allow the eventual addition of a graywater system is a reasonable investment in a better future. These systems are in some ways similar to rainwater harvesting mentioned before
(Site & Landscape).

Why do it?

The water savings possible through graywater recovery are substantial. There's no need to use valuable treated water for toilet flushing when graywater will do the job just as well. Additionally, using graywater onsite keeps water out of the sewer system (or your septic system), reducing the burden on these facilities.

How to do this?

A graywater system consists of draining waste from sinks, showers, and laundry to a holding tank; a filtration or treatment system; and graywater supply plumbing to toilet tanks and irrigation runs. Pre–plumbing for graywater ranges from just adding a few extra plumbing Y's at these locations to placing additional supply lines or even mains, for very large installations. Also, be sure you have space available for a future storage tank and filter.

Who does this?

Plumbing engineers, plumbers.


Front loading washer image

Household appliances such as front–loading washing machines represent another large opportunity for water and cost savings.


Goal: Reduce environmental impacts from materials production

PVC, or polyvinyl chloride, is a common plastic material — ubiquitous as white plastic piping — with some serious environmental problems. PVC's manufacturing process is the leading source of toxic dioxin, a known carcinogen and one of the worst environmental pollutants in the United States. According to the Healthy Building Network, PVC is manufactured predominantly in low–income communities in Texas and Louisiana, which raises environmental justice concerns over the release of dioxins and resulting health issues. While other pipe materials have associated environmental problems, such as the destruction and pollution caused by most copper mining, PVC is not recyclable (unlike copper and many other materials) so its ongoing use means continued dioxin production.

area one

Use sustainable materials for pipes

What is this?

While no material available today is endlessly recyclable with no production of unwanted byproducts or undue energy use, the various choices for piping have different levels of negative environmental impacts.

Why do it?

Choosing sustainable materials reduces pollution in water, groundwater, and air, protecting individuals from environmental health problems.

How to do this?

For water supply piping use cast iron, concrete, and plastics such as HDPE. For drain, waste and vent lines, use cast iron and ABS plastic. For either of these uses, copper and PEX plastic are suitable. Concrete, vitrified clay, and HDPE are appropriate for sewer pipes. With copper pipe, be sure to use best practices to avoid flow restrictions and environmental releases of copper due to poor soldering or rough pipe ends.

Who does this?

Architects, specification writers, plumbers.


More Information

California Urban Water Conservation Council, Home Conservation Tour
Healthy Building Network