The “Second Time Around”:
Can Wastewater Have a Productive Life as “Reclaimed Water”?
Imagine that the water spitting out of sprinkler systems on lawns, public parks, roadway
medians, and golf courses originally came from somebody’s toilet.
Welcome to St. Petersburg, Florida. Welcome to south San Francisco Bay. Welcome to
Phoenix.
Welcome to Raleigh?
In densely populated, water-strapped cities in places like Florida, California and Arizona,
treated wastewater, or “reclaimed water,” is a daily reality. In an effort to conserve sources of
potable water, or freshwater suitable for needs such as drinking, cooking and bathing, these cities
use reclaimed water for irrigation, street washing, or industrial cooling. The noisy ticking of a
sprinkler is a constant reminder that reclaimed water is helping to conserve precious freshwater
resources.
In a state like North Carolina, where water resources currently seem plentiful, the notion
of putting water that was once in our toilets, bathtubs and sinks on lawns may seem ridiculous, if
not disturbing. But as politicians debate the validity of global warming and forecasters around
the nation hint at the possibility of yet another hot and dry summer, the consequences of the
Triangle’s unrelenting growth and development come into sharp focus: Its constant demand for
freshwater is causing increased strain on the region’s potable water resources.
On any given day, Wake County residents are likely to use more freshwater to flush their
toilets and wash their hands than they use for drinking. But after they’ve flushed their toilets and
turned off their faucets, the water they’ve used is far from being gone. Instead, it is funneled to
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one of the publicly owned wastewater treatment plants where it is treated and then discharged
into local waterways such as the Neuse River.
Traditionally, officials have viewed the wastewater slipping down the drains of more than
240,000 Wake County households as troublesome byproduct of progress ─ to be disposed of as
quickly and efficiently as possible. But as Wake continues to grow, increasing amounts of both
residential and industrial wastewater mean that cities and towns must worry about pushing up
against their state-allocated discharge permit limits (See related story: Abuse of the Neuse?),
forcing county and city officials to begin exploring more innovative strategies for long-term
wastewater management, including water reclamation.
Rethinking Wastewater
“More and more municipalities are looking at re-use,” says Dr. Bob Rubin, professor of
agricultural engineering at North Carolina State University. Re-use can significantly reduce the
per capita consumption of freshwater and help wastewater facilities stay in compliance with their
permit limits for nutrient discharge, he says. In fact, the 1998 Wake County Water/Sewer Plan
identified water reclamation as one of its key tools for its water and sewer management strategy.
Many communities in the Triangle have already started to explore reclaimed water
systems: The town of Cary operates two reclaimed water systems that pump approximately five
million gallons of highly treated wastewater per day for reuse customers that include John Deere
and WorldCom. The majority of Cary’s reclaimed water customers are located near the two
treatment facilities, and the town delivers reclaimed water to its customers via a separate,
intricate piping system that runs parallel to potable water lines.
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And the City of Raleigh is exploring an expansion of its water reclamation system, which
is currently limited to irrigating a field near the Neuse River Wastewater Treatment facility. The
city is working with Black and Veatch, an international consulting company, to prepare a master
plan for a future reclaimed water system. Such a plan could include infrastructure similar to the
city’s drinking water master plan, which contains over more than 1,300 miles of water mains and
1,500 miles of sewer mains.
But laying enough pipes from the plant to the furthest reaches of the city could take
almost 40 years at variable expense, says Tim Woody, the reuse superintendent.
“Obviously, getting reused water to certain sections [of the city] will be cheaper,” he
says, citing businesses and industry near the Neuse River Treatment Plant. “Getting it to
someplace like Carter-Finley Stadium, some 20 miles away, would be more expensive.”
But given the considerable expense of following the footprint of the drinking water
master plan, the city is exploring alternative technologies for a reclamation system, including
water-scalping units, which create and distribute reclaimed water much closer to potential
customers.
Common in dry regions like California and Arizona, scalping units are attached to
existing pump stations and function like mini-wastewater treatment plants: they take in
wastewater from the pump station and treat it to reuse standards using biological or chemical
processes. Ultimately, the scalping unit has the potential to produce reclaimed water closer to
customers needing non-potable water for purposes such as irrigation and industrial cooling.
“We’d be taking the treatment mechanisms to the market,” says Woody.
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Public Skepticism and Concern
Experts say that reclaimed water doesn’t smell or look any different than potable water,
but it is unlikely that Triangle residents will ever find it coming out of their faucets or
showerheads. Currently, reclaimed water is not directly reused as drinking water anywhere in the
United States, although there has been some controversy in California over the notion of
injecting reclaimed water into underground aquifers to help replenish potable water supplies.
Instead, reclamation efforts focus on producing non-potable water -- water that isn’t intended to
be drinkable but is perfectly suitable for uses such as residential and commercial irrigation.
Public skepticism about the mere concept of reclaimed water is likely to run deep,
however, especially given the poor image of wastewater treatment technology in the Triangle.
Last March, the City of Cary received complaints from residents and I-40 commuters about the
stench wafting from the wastewater treatment plant near the Harrison Avenue exit. In June 2002,
the public learned about Raleigh’s sludge application debacle: the Neuse River Wastewater
Treatment Plant contaminated nearby groundwater by spraying too much sludge, or solids left
over from the water treatment process, on adjacent farmland.
But perhaps the most damaging blow to the concept of reclaimed water came earlier this
year when controversy erupted over placing privately owned, lagoon-and-spray systems in two
new eastern Wake County subdivisions that aren’t connected to city water and sewer services.
In short, these systems divert human waste to large holding tanks where bacteria digest
the solids. The resulting liquid is treated and sprayed on a nearby field that absorbs excess
nutrients. The systems are similar to those used in the hog farming industry, but given the spotty
environmental history of hog waste lagoons, nearby residents on well water were concerned that
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the systems could contaminate their groundwater. Due to citizen pressure, the Wake County
Board of Commissioners rescinded the developer’s permits for implementing the systems.
But it is erroneous to compare municipal reclaimed water systems to spray-irrigation
systems like the one at the Neuse River Wastewater Treatment plant or privately owned lagoonand-spray systems, says Kim Fisher, Cary’s public works and utilities director.
The standards of treatment are markedly different, he explains. The spray technologies
don’t treat wastewater to the same level as does a municipal reclamation system, which uses
physical, biological and chemical processes to remove bacteria and microbes, as well as to
reduce concentrations of nutrients like nitrogen and phosphorous. In fact, the resulting quality of
reclaimed water often surpasses that of water drawn from rivers and lakes before it is treated and
distributed as potable water, says Tim Woody, the reuse superintendent of public utilities in
Raleigh.
“One of the greatest challenges in implementing reclaimed water infrastructure and
policy is convincing the public that reclaimed water is safe and beneficial,” says Dr. Rubin.
Fisher, Cary’s public works and utilities director, says that an extensive and ongoing public
relations campaign helps convince many residents that reclaimed water is a prudent measure for
conserving water resources.
But the public’s initial fear about reused water is simple: It likely originated in someone’s
toilet, sink, or shower. And sending waste “away” somewhere is an accepted and almost
unquestioned societal practice, says Rubin. Implementing policies and procedures to reuse
wastewater asks people to completely rethink their cultural assumptions about waste that have
likely been ingrained since birth.
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Other Alternatives
If municipal reclaimed water systems aren’t economically feasible or don’t fly with the
public, what about spray-irrigation technologies? The implementation of spray-irrigation
technology in Pamlico County’s Bay River Metropolitan Sewerage District a few years ago was
hailed as a success for reducing the area’s nitrogen discharge into the lower Neuse River, says
Dean Naujoks, Upper Neuse riverkeeper for the Neuse River Foundation, a non-profit citizen’s
environmental watchdog group.
Currently, privately owned lagoon-and-spray irrigation systems, like those proposed for
new subdivisions in Wake County, are developers’ answer to building new communities in rural
areas where city water and sewer utilities are not available. If developers keep pushing for the
non-discharge lagoon-and-spray systems, an alternative might be to place them under centralized
management by local or regional government, Dr. Rubin suggests.
Critics of the lagoon-and-spray systems say the systems work in theory-- when they are
run on test grounds and under close supervision. “If you do it just right, it works,” says Stan
Norwalk, a former member of the Wake County Planning Board and outspoken environmental
advocate. “But it takes a lot to do it right.”
Ideally, the vegetation on the land is supposed to absorb the excess nutrients, such as
nitrogen and phosphorous, from the discharged wastewater. However, the right balance has to be
struck among land area, soil type, saturation limits and plant species, says Norwalk, and he is
worried that rules and regulations for such systems are insufficient at the county level.
“If Wake County were to try and incorporate several such systems into their wastewater
management plan, it would need to hammer out some new county regulations and guidelines,”
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says Norwalk. There are currently no county ordinances regarding wastewater treatment systems
that discharge on land aboveground, only state regulations.
Besides, Wake County already has thousands of mini wastewater treatment systems in
operation, says Norwalk. “They’re called septic systems.” Septic systems are privately owned
sewage disposal systems that treat wastewater in a holding tank underground and then leach the
effluent into the soil. And septic systems, Norwalk notes, aren’t inspected by the county or state
as often as they should be due to staff and money shortages.
Norwalk fears that, even under centralized management, inspections of decentralized
spray-irrigation systems would also fall by the wayside.
Municipal Reclaimed Water Systems
Spray-irrigation systems are also limited by how much water a given area of land can
absorb, says Dr. Rubin. Once the land is saturated, nutrient-rich water slides off the top ─ much
like a paved parking lot on a rainy day ─ and contributes to pollution of local rivers, streams, and
lakes.
That’s where municipal reclaimed water systems have distinct advantages, says Tim
Woody of Raleigh’s public utilities department. Whether these reclamation systems are scalping
units or pipes connected to a large municipal reclamation plant, they do not have “a closed loop
arrangement” like spray irrigation systems, he explains. Spray systems are forced to discharge on
land, but a municipal reclaimed water system’s infrastructure would still allow treated
wastewater to be discharged into rivers during a season of heavy rains.
Even though the Triangle doesn’t have the added difficulty of an arid climate like states
in the Southwest, its increasing population continues to stress potable water supplies, and
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reclaimed water systems could significantly ease that strain by producing water specifically
intended for non-potable uses, such as street washing or watering golf courses and parks.
Last summer, the town of Cary was able to reuse approximately 1 million gallons of
treated wastewater on days when temperatures climbed and water usage peaked. During 2003 the
town reused more than 37 million gallons of water, effectively reducing the amount of potable
water used for residential and commercial irrigation, manufacturing processes, and industrial
cooling.
Besides conserving potable water supplies, widespread use of reclaimed water helps
decrease the amount of wastewater effluent that treatment plants discharge into the Neuse River
Basin. This reduces pollutants in the waterway and, as the Triangle keeps growing, helps
wastewater treatment plants stay in compliance with their permit limits for nutrient discharge
into the river.
If forecaster predictions of a dry summer are correct, another drought may not be such a
bad thing for Wake. Sure ─ reservoirs will shrink, lawns will go brown, and neighbors will
report each other for watering on the wrong day. But another drought can could also provide an
impetus for leaders to step up the pace of current water reclamation efforts so that both current
and future residents can benefit from responsible growth in Wake County.
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SIDEBAR
Water Reuse Technologies
Municipal Reclamation Plant
Wastewater is piped into a municipal plant where it is put through advanced physical,
biological and chemical treatments and then re-distributed using a piping system that often
parallels a city or town’s water and sewer master plan. This is the type of system used in the
town of Cary. The cost and time associated with laying miles of new pipe from the plant is a
common constraint for larger municipalities.
Water Scalping Units
Attached to existing pump stations, water scalping units function like mini wastewater
treatment plants. They remove wastewater from the pump station and put it through advanced
physical, biological and chemical treatments. The result is reclaimed water produced much closer
to potential customers. Water scalping units were first introduced to North Carolina when Oak
Island, in Brunswick County, began planning to expand their sewer systems last year. The town
hopes to locate the scalping unit near a local sports field or golf course that could be irrigated
with reclaimed water.
Spray Irrigation or Surface Discharge Systems
These systems treat human waste by putting it into a large holding tank where bacteria
digest the solids. The resulting liquid is then treated and sprayed on a nearby field that absorbs
excess nutrients. Developers advocate these systems for new subdivisions in rural areas of Wake
County. Nearby residents and environmental activists oppose the systems, however, fearing that
discharge containing raw sewage could contaminate groundwater if the systems malfunction or
aren’t properly maintained. In a report released last January, the Illinois Environmental
Protection Agency reported that of more than 140,000 surface discharge systems operating in the
state, between 30 and 60 percent of the systems are either failing or have failed.
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