For most of this summer, residents of much of the Midwest, Central Plains and Texas held onto the hope that it would rain. But because the rain usually evaporated before it hit the ground, little relief came from the series of hurricanes that bombarded the Southeast and Hurricane Katrina that later hit the Gulf Coast. As a result, communities were put on sprinkler watering restrictions and residents were urged to conserve water at home. Meteorologists declared it one of the worst regional droughts since 1988.

As droughts and population booms continue to stress fresh water supplies, municipal wastewater reclamation and reuse increasingly will help alleviate the country's water deficits. Reclaimed water was formerly used in the United States mainly for purposes that did not require high-quality water, such as pasture or nonfood crop irrigation. Today, highly treated wastewater is valued as a resource that, in recent years, has been used for urban irrigation, toilet flushing, industrial needs and indirect potable reuse. Reclaimed water also is used to prevent seawater intrusion and to recharge local underground aquifers. Additionally, industrial users purchase reclaimed water to use in cooling towers, boiler feed and other manufacturing processes. Currently, the United States produces the most reclaimed water in the world, averaging about 2.6 billion gallons daily.

However, some state regulatory agencies have just begun to recognize the value of reclaimed water. Many states recently have developed their first water reuse and reclamation regulations or are in the process of doing so.

Most water reuse projects are located in Arizona, California, Colorado, Florida, Nevada, New Mexico and Texas. California and Florida account for nearly half the total annual reclaimed water use in the nation. Other states — including the Carolinas, Georgia, Virginia, Washington and even relatively water-rich states in the Northeast — also are starting to adopt water reuse programs.

Although the drought spared most of the West this year, many municipalities in the region have become accustomed to — and prepared for — water shortages. While some continue to purchase water from private utilities or pay penalties for exceeding their water extraction limits, they realize those are only short-term, and rather expensive, options. Others seeking long-term relief, such as the Scottsdale, Ariz., Water Resources Department and the West Basin Municipal Water District in southern Los Angeles County, Calif., have pioneered water reuse and other conservation programs.

Located in states that have strict water allocation and discharge regulations, West Basin and Scottsdale have two of the nation's strongest conservation and sustainable environment programs. The utilities' reuse programs conserve water and reduce operating costs, and also encourage residents to conserve through incentive programs such as low-flow toilet installation, and rebates for low water-using landscapes and high-efficiency clothes washers. To date, West Basin and Scottsdale's reclamation programs have saved more than 90 billion gallons of potable water.

Promoting sustainability

Located in the middle of the Arizona desert, Scottsdale has been planning for droughts for many years. Burdened by increasing wastewater disposal costs, the city implemented a water reuse program more than 20 years ago. To treat its reclaimed water, the Scottsdale Water Campus facility uses a membrane technology as a pretreatment to reverse osmosis (RO), producing high quality processed water suitable for landscape irrigation and groundwater recharge.

“Although we've been reclaiming our water since 1984, it wasn't until 1998 that we actually started reusing it,” says Art Nunez, acting water/wastewater treatment director at the Scottsdale Water Campus. “Up until then, we had just poured usable water down the drain — and we paid to dispose of it.”

Scottsdale began effluent reuse on its golf courses in 1984 and expanded its use in 1998, saving an estimated 25 billion gallons of potable water. In fact, the Scottsdale Water Campus is one of the largest municipal facilities in the world that treats raw wastewater to potable quality for aquifer recharge. It does so by injecting highly treated reclaimed water directly into an underground aquifer via wells. Recharging excess effluent allows the city to store accumulated withdrawal credits until needed during peak periods, reducing the city's water demand from the Colorado River as well as its water treatment requirements.

Scottsdale currently draws more than 65 percent of its drinking water from the Colorado River and pumps another 30 percent from city wells. Other surface water sources supply the rest of the city's drinking water. “Our goal is to replace any pumped groundwater with groundwater recharge,” says Beth Miller, an advisor to Scottsdale Water Resources. “We'll only use [groundwater supplies] if surface water supplies are unavailable.”

To help offset additional surface water purchases, the city assesses a water resources acquisition fee for all new housing developments. The city has used the money to more than double its available surface water supplies. “We have invested a lot of time, effort and money in creating a long-term water supply,” Nunez says. “We expect this water solution will help sustain our continued population growth for years to come.”

Golf courses use much of Scottsdale's reclaimed water; 23 of the 42 area courses use it for irrigation and pay all reclamation fees. New golf courses must provide their own renewable surface water supply. “Scottsdale has a reputation for having lots of golf courses, but residents are not aware that those golf courses are using reclaimed water and are not using drinking water [for irrigation],” Miller says. “One of our challenges is educating our general public about that reuse and how important it is.”

Miller says that between 60 and 80 percent of Scottsdale's water is used for landscape watering, so the city holds workshops that advocate landscaping with drought-resistant plants, trees and shrubs. “We offer workshops on everything from rejuvenating existing landscapes to designing a new landscape,” Miller says. “Interest is definitely growing. In the newer neighborhoods, the ethic is much more toward [planting] low-water-using landscapes.”

The city also rebates residences and businesses for replacing grass with low water-using plants and for installing water-efficient plumbing fixtures. It conducts residential irrigation water audits and recommends ways to conserve water. Residents that add greywater piping to their homes beginning in 2007 will receive a $200 state tax credit.

Leading by example, Scottsdale uses rain-sensor irrigation systems in its parks and re-circulating pumps in its main fountains. The city also has started replacing older plumbing fixtures in its buildings with water-efficient devices.

“The Scottsdale Water Campus, with its ability to reclaim water for landscape irrigation and groundwater recharge, was a giant step forward in the wise use of Scottsdale's water resources,” Miller says. “Scottsdale must continue to build on its history of environmental stewardship and conservation to leave a legacy for future generations.”

Setting standards

The West Basin Municipal Water District in Southern California was one of several water supply agencies that enacted conservation regulations in the 1990s because of water extraction restrictions and high water import fees. The district imports water to 17 cities in the South Bay and unincorporated areas of Los Angeles County. It produces five different types of reclaimed water: tertiary, nitrified tertiary, softened RO, pure RO and ultra-pure RO — all state-approved for various municipal, commercial and industrial applications (see “Five ‘designer’ reclaimed water qualities” on p. 38).

West Basin was one of the nation's first water agencies to create large-scale wastewater reclamation systems, and its Water Recycling Facility is the largest reclamation plant of its type in the United States. In 2002, the facility was named one of six National Centers for Water Treatment Technologies by the Fountain Valley, Calif.-based National Water Research Institute.

West Basin's first water reclamation plant opened in 1995. Capable of eventually treating 23 billion gallons of wastewater per year, West Basin's Water Recycling Facility currently treats 9 billion gallons of wastewater yearly from Los Angeles' Hyperion Wastewater Treatment Plant (WWTP). After completing its next expansion in May 2006, the facility will increase its reclaimed water production by 15 million gallons per day — 5 million for seawater barrier injection and 10 million for landscape irrigation. To date, West Basin's reclamation program has saved more than 65 billion gallons of potable water — enough to fill about 200,000 football stadiums.

The district purchases 10 percent of its secondary treated sewage water from the Hyperion WWTP, which decreases the volume the plant discharges into the Santa Monica Bay by 25 percent. In addition, the district has reduced its imported water by nearly 20 percent. “West Basin is committed to expanding the use of reclaimed water to safeguard the limited water supply and to achieve new milestones in water conservation,” says West Basin Board President Carol Kwan.

The district uses reclaimed water to augment the groundwater as a potable supply source. It also combines 50 percent imported water with 50 percent reclaimed water to inject into a series of wells that serve as a hydraulic dam between the ocean and the groundwater aquifer.

The Water Replenishment District of Southern California purchases reclaimed water from West Basin to use for seawater barrier injections. Many local municipalities and universities also use the treated water for irrigation. Inglewood, Calif., uses it for street sweeping, and Torrance, Calif.-based Toyota Motor Sales USA buys it for toilet and urinal flushing.

Industrial users in South Bay, Calif., including Chevron, ExxonMobil and BP, use the high-quality reclaimed water for cooling towers, boiler feed and various refining processes. To accommodate those industrial users' needs, West Basin built satellite treatment facilities at or near the refineries. Connections to the main pipelines eventually will provide reclaimed water to low-quantity users, such as garden nurseries and schools. By using high-quality processed water for their industrial applications, local refineries and other area industries, such as the Home Depot National Training Center and Goodyear, save billions of gallons of potable water annually for use by the more than 1 million residents within the West Basin service area. “We continue to establish valuable partnerships and strive for innovation to make this program one of the largest in the country,” Kwan says.

West Basin also offers a variety of incentives to encourage its residents and businesses to conserve water, including rebates for installing high-efficiency clothes washers and ultra-low-flush toilets. Businesses also receive incentives for installing cooling tower conductivity controllers, water-saving toilets and urinals, pre-rinse kitchen sprayers and water-pressurized brooms. Hospitals and other health care facilities receive rebates if they retrofit x-ray machines with film processor re-circulating systems as do hotels and motels that use do-not-wash guest towel and bed linen placards. “Our goal is to remain in the forefront of water resource planning and management to ensure a reliable supply for today and the future,” Kwan says.

Affected by drought, increasing pollution and development, communities likely will depend more on water reuse to relieve dwindling water supplies. Potable and nonpotable water reuse programs that use a variety of conventional and advanced water treatment technologies have proved they are a reliable way to provide water for various residential, commercial, municipal, industrial and agricultural purposes.

This year's drought was proof that all utilities must be prepared for the unusual and even the inevitable. By putting water reuse and conservation measures in place, Scottsdale, West Basin and other water agencies have provided their customers with a steady supply of safe, high-quality water for years to come.

David Mansfield is general manager for the Scottsdale, Ariz., Water Resources Department. Paul Shoenberger is chief of engineering and operations at the West and Central Basin Municipal Water Districts in southern Los Angeles County, Calif. James Crook is on the Water Reuse Association's Board of Directors, and is an environmental engineering consultant based in Boston. Karen DeCampli is municipal marketing director for USFilter, a division of Siemens Water Technologies, in Warrendale, Pa.

How much drinking water goes down the drain?

Americans use more than 1,500 gallons of water daily per capita, including 650 gallons for crop irrigation, 820 gallons for manufacturing and 100 gallons for household use, according to the Environmental Protection Agency. Between 50 and 70 percent of residential water is used outdoors for activities such as watering lawns and gardens, washing cars and hosing down sidewalks. Only 30 to 50 percent is used for potable needs, such as drinking, cooking and bathing, according to the Denver-based American Water Works Association.

Per capita, an additional 120,000 people could have drinking water if just one municipality or industrial site treated and reused 12 million gallons of wastewater each day. In one year, such a reuse program would conserve nearly 4.4 billion gallons of drinking water.
— Mansfield, Shoenberger, Crook and DeCampli

The amount of water used by industries is staggering. For instance, it takes:

• between 39,000 gallons and 105,000 gallons of water to produce just one automobile;

• 1,851 gallons of water to refine a single barrel of crude oil; and

• between 60,000 and 190,000 gallons of water to produce one ton of pulp for packaging materials.

Five ‘designer’ reclaimed water qualities

• Tertiary water: Secondary treated wastewater that has been filtered and disinfected for a wide variety of industrial and irrigation uses.

• Nitrified tertiary water: Tertiary water that has been nitrified to remove ammonia for industrial cooling towers.

• Softened reverse osmosis (RO) water: Secondary treated wastewater pretreated by either lime clarification or microfiltration, followed by RO and disinfection for groundwater recharge, which is superior to state and federal drinking water standards.

• Pure RO water: Secondary treated wastewater that has undergone microfiltration, RO and disinfection for low-pressure boiler feed water.

• Ultra-pure RO water: Secondary treated water that has undergone microfiltration, RO, disinfection and second-pass RO for high-pressure boiler feed water.
  — Mansfield, Shoenberger, Crook and DeCampli