By Peter Friederici
High Country News
Sometime this fall, Mike Nivison plans to take a healthy swig
of water that exemplifies everything you'd expect from a small resort town set
high in a Western mountain range. The water will be cool, clear, refreshing.
But it won't be pristine spring water pouring from some mossy crevice.
Nivison is Cloudcroft's village administrator, and what he
anticipates savouring will come from the village's drinking-water treatment
plant — and, not too long before that, from its sewage treatment facility.
Cloudcroft's will be one of the first wastewater systems in the
United States to allow — or require, depending on your perspective — residents
to drink treated wastewater that hasn't been naturally cleansed in a river or
aquifer. It will be built entirely as a matter of necessity. At an elevation of
more than 8,500 feet in southern New Mexico's Sacramento Mountains, Cloudcroft
is high and, thanks to recent years of drought, dry.
"A city like San Diego can go buy more water," says
Bruce Thomson, a University of New Mexico civil engineer who has been helping
Cloudcroft develop its new water system. "It's expensive, but they can.
But Cloudcroft is simply out of water. Because they're at the top of the
mountain, there's no new place to drill wells. They're at the top of the
watershed. They don't have any other alternatives."
Cloudcroft has only about 750 residents, but its population
swells to a few thousand on summer weekends. All those people escaping the
lowland heat can use more than a third of a million gallons of water on a
single hot Saturday. But the village's major wells produce only about 150,000
gallons a day. To make up the shortfall, village officials have resorted in
recent years to hauling water, which is expensive, inconvenient and
energy-intensive.
Nivison figured that Cloudcroft's only sure source of what he
calls "wet water" — that is, usable liquid, rather than theoretical
legal rights or hard-to-reach water that might be buried somewhere deep
underground — was right at his feet, in the stream of effluent pouring from the
village's wastewater treatment plant. With several million dollars in state
funding and the help of engineers from two universities and a private firm, the
village has been building a plant to purify that water. After conventional
treatments that settle solids and utilize microbes to degrade or remove
pathogens, the plant will use multiple filtration methods, including reverse
osmosis, to remove chemical contaminants. Then the water will be sent to
covered tanks and mixed with groundwater pumped from the village wells.
After three or four weeks, the blend will be sent back through
drinking-water treatment and distributed for use. The wastes squeezed out
during the reverse osmosis process, meanwhile, will be concentrated in briny
effluent, which the village will store for use in dust control on roads,
fighting fires, and, possibly, for making artificial snow at the local ski
area.
And then the toilets will flush, and the sinks and tubs will
drain, and the cycle will repeat again — and if Nivison and his collaborators
are lucky, no one will think much about it.
"By any parameter you can measure — suspended particles,
salts, bacteria, pharmaceuticals — the water from this process is going to be
extraordinarily clean," Thomson says. "But you have to overcome the
'yuck factor.' It's not measurable, it's not quantifiable, but it's every bit
as important as the particles you can measure."
"All we've done is recycle the same water on this earth
since the beginning of time," Mike Nivison says. "This is just a more
controlled environment for doing the same thing. I do believe this will be our
salvation."
As the West grows in population, and as climate change seems to
be decreasing the reliability of some water supplies, some of the region's
residents are reconsidering the notion that effluent is something to get rid of
as efficiently as possible. Only a few are willing to go quite as far, yet, as
Mike Nivison, but many are at least embracing the idea that wastewater is a
valuable resource. What's happening in Cloudcroft, then, is a portent of what
is happening, and what likely will happen, in other arid places.
But the prospect of brewing your morning coffee with water that was recently washing greasy dishes or flushing a neighbour's toilet has many people uneasy, and not just because of what psychologists and water engineers alike call the "yuck factor." The water to be recycled may carry a host of pollutants, some recognized only recently. Among the most worrisome are endocrine disruptors, which pose potentially large but as yet incompletely proven health threats that are making some scientists very nervous.
San Diego’s problem
Twice in the last 10 years, San Diego city officials have
proposed augmenting the city's drinking water supply with water reclaimed from
the city's sewers — and twice, in 1999 and again last year, those plans have
been shot down.
It is a telling comment on the disjointed nature of much water
management in the United States that San Diego has both a water-supply and a
water-disposal problem. On the supply side, the city imports between 85 and 95
per cent of its water from distant sources — specifically, from the Colorado
River and the California State Water Project, which conveys water from Northern
California to the state's dry southern half. Those sources have historically
been reliable, but only up to a point. In 1991, during a severe drought, water
project deliveries were on the verge of being drastically cut when the rains
finally came; this year, water planners are asking users to make voluntary
cutbacks. And current climate projections suggest that the flow of the already
over-allocated Colorado River may decline significantly in the future.
For wastewater disposal, San Diego relies on a water-treatment
plant at Point Loma whose technology is antiquated. It discharges effluent that
does not meet Clean Water Act standards into the Pacific. San Diego has a waiver
from the federal Environmental Protection Agency allowing it to dump that
effluent, but the waiver expires in 2008. The cost of upgrading the Point Loma
facility to meet EPA standards has been estimated at $1 billion, and the city
has yet to make plans to raise that money.
As part of a settlement agreement stemming from a lawsuit by
the EPA and environmental groups, San Diego agreed to reduce its effluent
discharge into the ocean by building two plants to treat water for reuse in the
city and its surroundings. Those plants are now capable of putting out 37.5
million gallons of reclaimed, non-potable water a day.
Like many other municipalities in the West, San Diego sells
some of its reclaimed water to buyers who use it to water golf courses, feed
industrial processes, and flush toilets. It's distributed in a network of
purple pipes to distinguish it from the potable water supply, and it's
currently available at about a third the cost of potable water. The trouble is
that the purple-pipe network amounts to an entirely new, parallel water system,
and San Diego, like many other cities, hasn't extended it very far.
"It's expensive to pay for the distribution of recycled
water," says Maria Mariscal, senior water resources specialist for the San
Diego County Water Authority. "Installing purple pipe in new developments
is OK, but retrofitting in established areas can be expensive."
As a result, the city is able to sell only about a third of its
recycled water capacity and is unlikely to meet its target, developed as part
of the lawsuit settlement, of selling at least 50 per cent by 2010.
To figure out how to use more of the reclaimed water, the city
Water Department conducted a study that recommended treating it intensively and
returning it to the potable water system. The system would be like Cloudcroft's
on steroids: 16 million gallons a day rather than 100,000. Using the treated
water to supplement San Diego's drinking-water system at a single point would
be much more cost-effective than piping the treated water to an entire network
of dispersed users of non-potable water.
Turning treated effluent into drinking water is a widespread
practice. It's most commonly done when communities dump their effluent into
streams and rivers, knowing that other users downstream will use the same
water. But an increasing number of communities are reusing their own water. In
Orange County, El Paso, Tucson, and many other Western communities, water
agencies recycle by dumping treated effluent on the ground so that it can soak
in and recharge aquifers. After that water's been underground for a while, it
is then pumped up for drinking water use.
San Diego's topography, though, doesn't lend itself to
recharging water from the treatment plants into local aquifers. So planners
proposed pumping the treated effluent into a reservoir that feeds the city's
drinking water system. The city council's Natural Resources and Culture
Committee agreed and forwarded the proposal to the full council. A wide range
of stakeholders on a community panel agreed, too.
"To me, this is a win-win," says Bruce Reznik,
executive director of San Diego Coastkeeper, an environmental group that
monitors coastal pollution. "You're discharging less into the ocean, and
you're creating a local water supply that you otherwise wouldn't have."
But opponents exploded, labeling the idea with a visceral and
unforgettable moniker of the sort no politician can afford to ignore.
"Your golden retriever may drink out of the toilet with no ill
effects," editorialized the
San Diego Union-Tribune
under the headline "Yuck!". "But that
doesn't mean humans should do the same. San Diego's infamous 'toilet to tap'
plan is back once again, courtesy of Water Department bureaucrats who are
prodding the City Council to adopt this very costly boondoggle."
Mayor Jerry Sanders came to much the same conclusion,
announcing in July of last year that he would not support the reservoir
augmentation plan. A year later, the city council has yet to decide on any new
wastewater reuse strategies.
"It was certainly disappointing," says Jim Crook, a
consultant who helped draft California's water-reuse guidelines in the 1970s
and served on an independent task force evaluating the city's proposal.
"It was a good project from a technical standpoint. We were very comfortable
with what they were going to do. The reclaimed water would be of a higher
quality than some of the raw water sources that are used now."
That, indeed, is one of the principal ironies here: Before it could even be used for reservoir augmentation, the water would be treated to a higher standard than what San Diegans are drinking now. Water discharged from the North City facility has already been shown to be at least as clean as water in some of the city's reservoirs. If it were to be dedicated to potable reuse, it would be subjected to further intensive treatment, such as reverse osmosis, before being pumped to the reservoir.
Reverse osmosis uses pressure to force water through a membrane
that allows water, but not most other molecules, to pass through. Using it
would bring San Diego's erstwhile wastewater up to a much better quality than,
say, the Colorado River, which receives the waste from hundreds of
municipalities and industrial users by the time it reaches Southern California.
Las Vegas alone discharges roughly 60 billion gallons of wastewater a year some
miles upstream of its own water intake — a feat of urban engineering that would
seem to prove that most of what happens in Vegas really does stay there. What
happens in Sin City is fueled by prescription and over-the-counter
pharmaceuticals, caffeine, sunscreen, synthetic compounds used in plastics and
detergents, and even methamphetamines, say researchers who have found all that
in Lake Mead's water.
Las Vegas' effluent is diluted as it flows downstream, and some
of the compounds in it are degraded by sunlight, destroyed by microbes, or
bound up in sediment. Still, monitoring in 2006 showed that water entering San
Diego's municipal system contained, before drinking-water treatment, small but
measurable quantities of ibuprofen, the insect repellent DEET, and the
anti-anxiety drug meprobamate.
"We can have a lot more monitoring and control if we
oversee our own reclamation than if we're relying on a river with a billion
gallons of recharge from other sources every day," says Bruce Reznik.
History matters
In Windhoek, Namibia, water from a wastewater treatment plant
is piped right back into the drinking-water system. NASA is developing advanced
recycling technology that will directly convert astronauts' urine into clean
drinking water. Such reuse systems are what a South African pioneer in water
reclamation, Lucas van Vuuren, was thinking of when he said, "Water should
be judged not by its history, but by its quality." Sufficient treatment, he
meant, assures that any water can be reused.
Van Vuuren's is a technocrat's line, though, because in fact
most people's tools for judging water quality aren't up to the task.
Conventional wastewater treatment is very good at removing the kind of
contaminants people can detect without laboratory equipment, such as odours,
suspended particles, and the sorts of bacteria that can cause illness. But most
people are relatively helpless when it comes to making more detailed
assessments of their water supply's safety. The lower Colorado River looks
clean enough; it's more likely to meet most people's standards than cleaner
water in a pipe outside a complex-looking treatment plant.
As a result of that perceptual shortfall, people are left with
nothing but water's history as a guideline, according to Brent Haddad of the
University of California at Santa Cruz, an environmental studies professor who
directs the university's new Center for Integrated Water Research.
A visceral aversion to unclean water, Haddad says, is an
understandable and useful tool that served the human species well through most
of its evolution. But it may not be particularly helpful today, when it's
necessary to make a decision between two sources of water that are both clear
and odourless — but from very different sources.
"When people are aware of the history of their water, it
matters a lot to them," he says. "If there's an unavoidable link to
prior urban use, that's troubling to people. It's extremely hard to convince
people then that the treatment will be good enough to override that history.
But people are willing to take Colorado River water or groundwater that's
clearly been used by other cities because it's easy to abstract away that use
and begin the water's history with its taking from the natural system."
Rivers and soils do, in fact, clean water. But the
psychological cleansing they do may be equally important. As a result, even the
Colorado River — however thoroughly dammed, diverted, and delivered through
aqueducts it may be — appears more natural, and cleaner, to many people than
what's produced by San Diego's wastewater treatment plants. The river takes the
yuck out.
The largely unwelcome prospect of drinking treated effluent, though, forces people to ask what's in the water they're already getting, whatever its source. Something long taken for granted becomes a public issue. And as people debate where their future water supplies are going to come from, an increasing number of experts and nonexperts alike are growing increasingly alarmed about the chemicals flowing not only from Las Vegas, but from every community.
Wastewater engineers are rightly proud of what their industry
achieved in the 20th century, bringing safe drinking water to virtually every
community in the United States. But most wastewater treatment plants were not
designed to remove the sorts of complex organic chemicals that show up in Lake
Mead — or, to cite a more pristine-looking example, Boulder Creek, which
tumbles out of the Rocky Mountains and through Boulder, Colo., before joining
the South Platte River.
Back in 2000, David Norris thought Boulder Creek an unlikely
place to look for unhealthy fish. Even below the city's wastewater treatment
plant, the creek
looked clean,
and fish
and other aquatic organisms lived throughout it. There was none of the stench,
the brown murk, or the belly-up fish associated with the bad old days of
piecemeal sewage treatment before the Clean Water Act was passed in 1972.
Norris, an endocrinologist at the University of Colorado — and
an avid fisherman — had read studies in the scientific literature documenting
the environmental effects of a poorly understood class of pollutants known as
endocrine disruptors. Unlike many toxins, they didn't appear to be killing
their victims outright. But in Lake Apopka, Fla., a pesticide spill had caused
lingering reproductive failures and sexual abnormalities in alligators. In
Britain, odd-looking fish that were not readily identifiable as males or
females, but had sexual characteristics of both, were turning up in anglers'
creels — especially in waterways below sewage outlets.
Norris and his colleagues, Alan Vajda and John Woodling,
figured that Boulder Creek's best indicators of environmental quality were
likely to be white suckers, a native fish that's widespread and not terribly
finicky about water quality. "A good healthy freshwater stream has a good
healthy sucker population," he says. "If you really disturb this
species, you've really disturbed the ecosystem."
Norris had no trouble finding white suckers both upstream and
downstream of Boulder's treatment plant. Upstream, everything seemed normal.
Downstream, it was not. "Much to our surprise," he says, "we
were appalled to see the extent of feminization in the fish population."
He found five female suckers for every male; further, 20 per cent of the fish
were "intersex" individuals showing characteristics of both sexes.
Alarmed, Norris looked for similar effects elsewhere, and found
them. Fish below wastewater treatment plants in Denver and Colorado Springs
showed some of the same symptoms. In the South Platte River, where Denver
releases its waste, he couldn't find a single male sucker below the effluent
outlet. Something in the effluent, it appeared, wasn't killing fish, but rather
causing hormonal changes in them and producing female traits in male fish.
The evidence was circumstantial, though. Norris knew he had to
more closely link cause and effect — which is hard to do in a natural setting,
where fish in different reaches of the same stream might be feeding on
different food, facing different temperatures, and otherwise dealing with
widely variable conditions. So he and his colleagues have since built two
"Fish Exposure Mobiles," which are basically mobile laboratories,
built inside trailers, with fish-holding tanks. By pumping combinations of
river water and wastewater effluent into the tanks on site, they're able to
replicate the pollution concentrations fish face at various distances below
treatment plants.
When they experimentally exposed fathead minnows — widely used
as a test fish — to water like that below the Boulder treatment plant, Norris
and his colleagues were able to feminize male fish within 14 days. They have
since tested fish in other Colorado waterways below wastewater treatment plants
in the Rocky Mountains and on the Western Slope. Data from those tests aren't
available yet, but Norris will say that he is awfully worried in general about
the presence of endocrine-disrupting chemicals in the environment, and in water
specifically.
"It's fairly obvious that living populations are being subjected to far more chemicals in the last 30 years than when biological systems evolved, and so we wonder what effect that has on the genetic machinery," he says. "If we want to increase the use of wastewater, unless we're going to remove these compounds from the water, we're going to increase their concentration in the human population, since we're just going to be adding more of these compounds. We keep concentrating our population in cities, and as a result we're concentrating our effluent."
Endocrine disruptors
Most of the organic compounds that can disrupt the endocrine
system are neither regulated by EPA standards nor often monitored in waterways
or the drinking-water system. Few thought they were a problem until recently.
But in a national survey published by the U.S. Geological Survey in 2002,
researchers found such substances in 80 per cent of the waterways they sampled.
The endocrine system is essentially a complex signaling
mechanism that tells genes and cells when to do what. It operates by means of
chemical messengers, or hormones, that bind to certain receptors in cells.
Unfortunately, many of those receptors aren't particularly picky. Receptors
designed to react to the natural hormone estrogen, for example, can also be set
off by a wide range of other compounds, from complex molecules that naturally
occur in vegetables to synthetic chemicals found in soaps, plastics,
pesticides, cleaning products and many of the other manufactured goods of
modern civilization. They get into sewage when people urinate, or shower, or
flush leftover pharmaceuticals down the toilet.
As in Boulder Creek, waterborne endocrine disruptors have in
many places been shown to have harmful effects on aquatic organisms, especially
fish. For example, male carp with unusually high levels of female hormones have
been found in Lake Mead, where estrogen — the kind naturally produced in human
bodies as well as the synthetic variety in birth-control pills — ends up when
Las Vegans flush their toilets.
Hormones naturally work at very low levels; a human estrogen
concentration as low as 1 part per trillion — so dilute that it's near the
lower limit of what monitoring equipment can detect — has been shown to affect
fish. The effluent dumped into Boulder Creek typically contains from 1 to 10
parts per trillion of human estrogen.
"People ask why such tiny levels have such a devastating
effect," says Norris. "But that's the level at which hormones work.
Parts per trillion is common stuff for an endocrinologist."
Consumers are used to thinking of drugs as having precisely
tailored effects. But endocrine disruptors don't work that way. Because many
different chemicals can activate a given set of hormone receptors, low doses of
quite different substances can combine into a higher dose. That's one of the
primary reasons a growing number of researchers worry about possible
implications for human health.
Wastewater treatment lowers concentrations of most trace
organic compounds — often by an order of magnitude or more — but it can't
remove them all. As a result, effluent often contains a stew of complex
chemicals. A recent U.S. Geological Survey study found that St. Vrain Creek,
into which Boulder Creek drains, carries measurable loads of at least 36
different compounds, including artificial fragrances, fire retardants,
antibacterial substances used in soaps, and substances used to manufacture
plastics. The extent to which those chemicals work together to cause effects on
the endocrine system — itself not well understood — is a big unknown.
"The endocrine system is much more than estrogens," says Catherine Propper, an endocrinologist at Northern Arizona University who has studied the effects of trace organics on amphibians. "We have this complicated endocrine system, and every time we find new aspects of it, we find they can be disrupted by some of these environmental contaminants."
It's difficult to draw lines of cause and effect between
exposure to endocrine disruptors and human disease or disorder because people
are exposed to so many chemicals from so many sources over many years, and
because some effects may take years or decades to manifest themselves.
Of course, humans aren't exposed to the chemicals in effluent
in the same way that Boulder Creek's white suckers are; we aren't swimming in
the water 24/7. And by the time a creek, or the Colorado River, enters our
faucets, the loads of trace organics poured into it from treatment plants
upstream have been significantly reduced. But the intensity of water use in the
West means that, in many river systems, water is taken in for further municipal
use before natural cleansing mechanisms can do their full work.
"Our rivers and lakes do clean water, especially if they
have long stretches between communities using it," says Theo Colborn, a
longtime pollution researcher who runs the nonprofit Endocrine Disruption
Exchange in Colorado and coauthored the 1996 book
Our Stolen Future
. "But we've exceeded their carrying and
assimilation capacity."
When surface water is taken in for municipal use, it is treated
with filtration and disinfection treatments that significantly reduce
contaminant concentrations. But low concentrations of some compounds — often in
the parts-per-trillion range — do remain to make their way into drinking water.
Some water experts argue that the amounts of endocrine
disruptors people ingest in water are insignificant compared to those we get
from other sources — plastic containers, foods, soaps, cosmetics, and many
other products.
But some biologists argue that the cumulative effects of
endocrine disruptors make it imperative to reduce their concentrations anywhere
possible.
"You would have to drink incredible amounts of the water
to amount to an effect that these chemicals naturally have," says David Norris.
"But adult humans are getting estrogenic compounds from an incredible
number of sources. So any amount we get from water will add to that, since
these chemicals have additive effects.
The water-processing system has to balance needs and costs.
People may choose to lower the quantities of trace organic compounds they
ingest with their water, but they're going to have to pay to do so. And that
means they'll have to consider how the risk represented by these chemicals
stacks up against others.
"What's more risky, bridges falling or the water you
drink?" asks Linton. "The utility folks are out there prioritizing
what to spend money on. They may need to focus resources on putting a new pipe
in rather than on removing a minuscule level of contaminants. There's a cost
associated with all these things."
If consumers do decide they want to lower their exposure to trace organics, though, then water-reuse projects of the sort San Diegans have rejected, for now, may be a good way to go. Such projects are expensive, but they have the virtue of providing dual benefits: concentrations of contaminants that will probably be as low as feasible, and a reliable flow.
But the yuck factor will surely continue to be an issue water
managers have to contend with. It seems to have deep roots in human history and
perception, after all, and perhaps will be overcome on a wide scale only when
it collides head-on with another deep-rooted but not always accurate Western
perception — namely, that the water will always be there.
Peter Friederici teaches journalism at Northern Arizona University in Flagstaff. His latest book is Nature's Restoration (Island Press, 2006 ). This story first appeared in High Country News.