It is almost impossible to find a public toilet in the US – and that creates problems. When desperate people pee in doorways and alleys, it offends residents and drives customers away from local businesses.

Enter the , a public urinal with an ecological twist. It uses biofilters – plants in a growing medium – to treat urine. Easy to move, it consumes less water than the average toilet and sink, while avoiding the harsh chemicals of conventional portable toilets. On top of all of that, its inventors claim it is odour-free.

The small booth of the PPlanter is not just for men: disposable funnels allow women to use the PPlanter standing up. The treatment process begins once the user washes their hands at a built-in sink. A foot pump pushes clean water through a faucet. The rinse water does double duty by flushing the urinal.

The water and urine empty into an air-tight tank; without exposure to air, urine does not produce malodorous ammonia. The liquids are pumped into a pallet-sized biofilter that is lightweight and movable, containing bamboo, wood chips, straw, rock and pectin-coated styrofoam. The bamboo takes up the water as well as nutrients in the urine, including nitrogen and phosphorus. Bacteria break down protein and carbohydrates. That leaves only salts.

Unconventional relief

The PPlanter was designed and built by the of Oakland, California. The idea was to reduce public urination while challenging people to rethink conventional plumbing. “Our goal is to refocus attention to developing ecological sanitation, making it aesthetically pleasing, clean, functional, and cool,” says lab founder Brent Bucknum.

Last year, Bucknum and his staff tested the PPlanter in a crowded San Francisco neighbourhood. It stood up well to heavy use and has relieved as many as 300 people over an 8-hour period. Now the city has ordered a permanent one with two urinals and a composting toilet. With proper maintenance, it should last 10-15 years. Additionally, Bucknum plans to rent PPlanters for festivals and events.

Bucknum hopes that international development agencies will be interested in installing PPlanters in nations lacking sewer infrastructure. But there is also a potential market close at hand, in dense neighbourhoods like those of San Francisco.

“The PPlanter is lower cost and lower maintenance than any other kind of toilet,” says Darryl Smith, co-director of the Luggage Store Gallery in the city’s Tenderloin neighbourhood. An outdoor portion of the gallery hosted a PPlanter for three months during testing, and he hopes to get one permanently. “The openness of the design keeps people from taking over these toilets to do drugs or other unhealthy things. It makes it safer.”

Chemical plants, landfills, oil refineries… odours so foul that they break the law are everywhere. Now we can keep them in check

WITH its two waste water treatment plants, a chemical company and a garbage truck depot, Chicago’s West Side industrial district is one of the worst smelling places in the city. But foul odours are exactly why I am here; I have come to witness the Nasal Ranger – the instrument of choice for measuring bad smells – in action.

My guide is Lynn Smith of Professional Service Industries, an environmental consultancy firm based in Oakbrook Terrace, Illinois. She relies on the Nasal Ranger to find out whether smells are potent enough to trigger huge fines.

Smith’s trusty Nasal Ranger looks a bit like a handheld ray gun, with a twist (see photo). On the front is a black dial pierced by six holes ranging in size from the width of a pencil lead to a mere pinprick. At the rear is a mask that you place over your nose. The two are connected by a barrel of Teflon, which resists residual odours. Two carbon-based filters are mounted on either side.

The Nasal Ranger allows Smith to precisely mix two streams of air before they hit her nose. Pungent ambient air enters through the holes at the front and mingles with odour-free air that enters via the filters. Twisting the dial changes the ratio of foul to filtered air, diluting the stench to the edge of detection. The idea is to find out the level you can no longer detect the smell, which is measured in the number of dilutions needed to get there.

We stand across the street from an oil terminal that smells strongly of rot, probably due to a sulphur compound used during oil processing. Smith buries her nose in the nasal mask and inhales, drawing a little harder than normal.

The oil terminal registers as a level-30 dilution. Those states in the US that regulate odour allow a dilution level of 7. Any smell measuring higher is considered a “nuisance” and can lead to hefty fines. The Nasal Ranger measures smells up to 60 dilutions – enough to send you reeling if sampled undiluted – and by fitting it with a spare dial it can measure odours detectable at 500 dilutions.

Some companies use the device to collect smell information in a pre-emptive strike before the introduction of regulations, says the Nasal Ranger’s inventor, Charles McGinley of St. Croix Sensory, based in Lake Elmo, Minnesota. “They believe that they do not smell that much and want to collect data to show that.”

“In the past, to understand the impact of an environmental odour, you would capture the odour in a container, bring it to the laboratory, dilute it successively, present those dilutions to panellists, and have them tell at what point they could detect the odour,” says Pamela Dalton of the Monell Chemical Senses Center in Philadelphia, who uses the Nasal Ranger to monitor the smells emitted by hog farms. “The Nasal Ranger allows you to do that in real time in the field.”