Safety of Reclaimed Water Discussed in Flagstaff, AZ

A panel was gathered at Northern Arizona University DuBois Center to answer questionsabout wastewater treatment techniques and the safety of using or drinking reclaimed water. Flagstaff plans to sell reclaimed water to an Arizona sledding facility for snow making.

The panel included Shane Snyder of the U of Arizona, Chuck Graf of the Arizona DEQ and Guy Carpenter, a water reuse proponent and engineer. Dr. Snyder indicated that there is no litmus test to say for sure of the water is safe and that a risk analysis needs to be done. Mr. Graf felt that the risk was minimal. Mr Carpenter noted that there has been no evidence to date that reclaimed water is causing problems.

The application discussed at the meeting, snow making only creates casual human contact. Studies with mice and other mammals indicate that there is no apparent risk from this use.

Last year, Flagstaff got about 40 percent of its total water supply from Lake Mary, another 40 percent from underground wells and about 20 percent by treating waste water. That waste water is used for golf courses (the biggest consumer), manufacturing and construction, but the majority of this water is sent down the Rio de Flag in central Flagstaff and east Flagstaff, where it ultimately becomes part of the groundwater supply.

A University of Minnesota study finding one of the more advanced sewage treatment plants in the country was releasing material found in drug-resistant bacteria that can sometimes be fatal for people, including Methicillin Resistant Staphylococcus Aureus (MRSA). No live bacteria were found, however. Public health experts said the finding from Minnesota was noteworthy and that few facilities nationwide were subject to testing that would detect the so-called “superbugs.”

It seems likely that the use of reclaimed water will likely require additional testing and more sophisticated treatment in the future. New treatment will likely involve the use of advanced oxidation processes and ozone to insure that micro pollutants and super bugs do not reach people. Studies of these techniques indicate that they are indeed effectively in cleaning up the water.

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Napa Adopts Ozone Treatment of Drinking Water

Twenty-four percent of Napa residents don’t drink the city’s tap water. Most people indicated that it’s because of a chlorine smell or taste. The chlorine is in the water to make sure it stays safe to drink as it travels through pipes leading from the treatment plant to taps.

In the spring, the city improved water quality by starting to use ozone at its largest treatment plant in Jameson Canyon, Costello said. Water treated with ozone has better taste and odor. The improved quality is expected to lead more people drinking tap water. Consuming tap water reduces the need for plastic water bottles. Other cities that have gone to ozone, as can be seen in past posts, have found consumer satisfaction rise. In fact, in blind tastings, the tap water often beats the bottle water.

While ozone offers many benefits for water treatment such as improved disinfection, reduction of disinfection byproducts, and improved clarification, taste and odor improvements are one of the main reasons why drinking water facilities adopt ozone. In fact, most bottled water is ozonated prior to bottling.

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Seattle Super Green Building Looks At Ozone Water Treatment

By late next year, Seattle’s Capitol Hill neighborhood will be home to a new six-story office building that strives to be the greenest commercial building in the world. The new structure will hold the offices of the environmentally-focused Bullitt Foundation. The Bullitt Center was designed to meet the requirements of the Living Building Challenge, and if it passes a self-sufficiency test after its first year, it will receive Living Building Status.

The criteria for a “living building” are determined by the International Living Future Institute, a Seattle-based organization dedicated to changing green building standards. The ILFI’s standards are considered to be the world’s hardest to meet. So far, only three buildings have been fully certified as Living, though about 100 other projects are in the works.

The building’s design aims to have net-zero emissions, meaning the building was designed to produce just as much energy as it uses. The roof of the building will be topped with photovoltaic panels that will produce enough energy in the summer to offset wintertime deficits and break even over the course of the year. The Bullitt center is expected to use less than one fourth of the energy of a normal building of its size.

The building also must supply and treat it’s own water, using a 50,000-gallon underground storm water cistern. One problem reported in the piece was regarding water treatment. Currently, the plans for the center show that it will collect rainwater for showers, sinks and drinking fountains, then filter the used water though a lower level green roof and landscaping. The raw sewage will be composted and sanitized before it’s shipped offsite to be converted into fertilizer. The problem, however, is that Washington State’s Department of Public Health requires public use buildings like this one that get water from anything other than the city, to chlorinate it.

Chlorine is on the prohibited list of the Living Building Challenge. The building’s designers are petitioning for ozone purification, which is a less toxic method. A number of green buildings have used or are considering the use of ozone as a green alternative to treating rain water or grey water in such applications. Ozone is made from oxygen in air and after use, ozone decomposes to back to oxygen leaving no disinfection by products. In addition, since it is made from air, there is no need to buy or store chemicals on site.

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