Recycled Sewerage

There’s been a lot of talk recently about recycled sewerage, particularly following Orange County’s decision to invest a lot of money and effort into providing their new bullet-proof reclaimed water system. The plant will process some 70 million gallons of water per day, making it the largest of it’s type in the world…

The Groundwater Replenishment System, as the $481 million plant here is known, is a labyrinth of tubing and tanks that sucks in treated sewer water the color of dark beer from a sanitation plant next door, and first runs it through microfilters to remove solids. The water then undergoes reverse osmosis, forcing it through thin, porous membranes at high pressure, before it is further cleansed with peroxide and ultraviolet light to break down any remaining pharmaceuticals and carcinogens.

The result, Mr. Markus said, ?is as pure as distilled water? and about the same cost as buying water from wholesalers.

From Sewage, Added Water for Drinking – New York Times

From the other side of the table, there’s a lot of resistance from people who believe that there is no way of removing all of the heavy metals and other pollutants that are found in industrial sources of sewerage, and others question the capabilities of the technology to remove “pharmaceuticals and carcinogens”.

John Kromko, a former Arizona state legislator… said he was skeptical about claims that the recycling process cleanses all contaminants from the water and he suggested that Tucson limit growth rather than find new ways to feed it.

?We really don?t know how safe it is,? he said. ?And if we controlled growth we would never have to worry about drinking it.?

An interesting resource is this pdf – Think Before You Agree To Drink (pdf 28 pages) which has some fantastic quotes, including this one from Professor Steven B. Oppenheimer, Director of the Centre for Cancer and Developmental Biology at California State Northbridge University at Los Angeles

The fact that some communities in the U.S and elsewhere have been drinking reclaimed water does not make it safe. It often takes decades to detect the damage done by such projects that tinker with public health and welfare.

Many communities feel forced to go this way, often under the guidance of smooth talking salesmen or consultants wanting to design or “test” their product in a live setting. The truth is that this technology really should be a last resort behind every other conservation method available. Too often cities are reluctant to tell people that they may need to change their ways, perhaps spend a bit of money to install low flow shower heads and dual flush toilets, and perhaps let their roses die off, after all it’s us or them when it comes to the crunch… right?

I wrote a couple of weeks ago about the little city of Orme in a piece titled Running out of Water? Can you believe that this city actually trucks water in an old fire engine from across the state line. I imagine that they foresee having to do this for as long as the rain holds off from refilling their reservoirs, or until their new pipeline joining to an adjacent town is completed…

Their efforts supply Orme with water for about three hours each day, around dinnertime, when children fight for the shower and their parents fill old milk jugs. It?s a hasty patch for the problem until Thanksgiving, when construction of a 2-mile pipeline is complete and the town can tap into Bridgeport?s water system.

But even after the problem is solved, this tiny town expects it might never escape the aftershocks of its summer without water. ?Everything changed when the water went out,? resident Gwyn Smith says. ?We never thought we?d have to live like this.? – Orme, Tenn.: The town without water


But back on the issue of recycled sewerage, the average small town or city will be far from able to utilize these technologies, if they are deemed to be safe, as the shear cost of construction and then operation is way outside the realm of all but the big cities. And on that note, I say let them have i, let them test it, and lets see the results in a few years. Just don’t expect me to support it in my backyard until someone can prove that all contaminants  in the wastewater stream can be removed, and that there are sophisticated safeguards to ensure that the end product is water beyond reproach.

Published by Mike Thomas

Mike Thomas P.Eng. ENV SP, is the author of and Director of Engineering at the City of Revelstoke in the Interior of British Columbia, Canada.

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