Spa resorts and wastewater. It’s pretty safe to say that when you think of one, you don’t typically think of the other. But forward-thinking El Monte Sagrado Living Resort and Spa in Taos, NM, chose an unusual onsite wastewater treatment system to manage its waste—one that actually introduces treated wastewater and the wastewater treatment process to the spa customers. And it does it—get this—in a very attractive (and safe!) way.
In a sense, you could say that the spa’s Living Machine systems (one for stormwater and one for wastewater) “beautify” the waste treatment process. El Monte, which opened in 2003, chose the Living Machine, designed by Living Designs Group, LLC, to demonstrate responsible wastewater treatment and reuse—in a way that looked, well...pretty.
As a plant-based system, the Living Machine looks like a tropical water garden. So it blended in perfectly with the theme of the resort, that of a lush water and plant environment. Plants are a prominent part of the Living Machine. They are in the treatment reactors (hydroponic reactors) and in the wetlands, and they provide a habitat for a complex treatment process. In the wetlands, plant roots help keep the wetland pores open and oxygenate the water (oxygen is required for microbiological decomposition). What’s unique about the system is that the plants are located in very prominent places in the spa (one is by the swimming pool). The system itself has to look good and must be odorless—something that is achieved by skillful engineering.
Virtually all the wastewater on the property is recycled through the Living Machine. This treatment system collects, treats, and reuses the wastewater for irrigation. Unlike most water treatment plants—typically eyesores designed to be hidden from view—the Living Machine is the heart of a greenhouse and botanical garden that the resort calls the Biolarium. Here, a beautiful swimming pool and hot tub are situated a few steps away from the heart of the wastewater treatment system, treatment tanks, wetlands (sprouting tropical plants), and the display pond, where the final treated effluent goes. The display pond, which boasts a large waterfall, is full of clear, final effluent, and tropical fish.
El Monte’s stormwater is collected and recirculated through a series of ponds, creating a beautiful oasis that’s attractive to fish, birds, and native flora.
El Monte guests are invited to swim in a cenote-like pond supplied with well and rainwater, to rejuvenate at a water-themed spa, and to stroll through an ecological wastewater treatment system that’s busy treating wastewater for reuse in subsurface site irrigation. In these ways and countless more, the El Monte Sagrado Resort is blurring the boundaries of ecology, architecture, and engineering to provide both service and serenity.
Intelligent, Conscious Development
As population steadily grows outside urban areas, so does the need for inventive and effective decentralized water and wastewater treatment systems. When such systems are used, facilities can avoid unduly taxing water resources and burdening the environment with discharges. Treated wastewater, wherever it’s generated, can be used as a source of new water for nonpotable use. Collected and treated stormwater can also be a significant source of nonpotable water, even in semi-arid climates.
Sustainable land development should ideally provide more usable land for recreational enjoyment, area beautification, and general landscaping by using reclaimed wastewater and collected stormwater. Integrated water management strategies and systems that become a part of the visual landscape of communities and developments—such as that at El Monte Sagrado Resort and Spa—are based on solid ecological engineering and landscape architecture.
The Cycle of Water
El Monte developer wanted to use a sustainable approach for management of both stormwater and wastewater at the resort. So to achieve this, two different versions of the Living Machine were installed on the site. The overall integrated management system provides irrigation with reclaimed wastewater and a unique double use of collected stormwater.
All wastewater from resort toilets, showers, hot tubs, restaurant, and laundry facilities flows to buried primary treatment tanks. These tanks remove solids, begin the breakdown of waste, and moderate the flow to the Living Machine system. From there, the water is pumped through a series of aerated reactors located in the Biolarium. The covered aerobic reactor removes a large fraction of dissolved organic pollutants while scrubbing odors in a planted biofilter located on top of the reactor. Next, the hydroponic reactors, with plants growing from racks at the water surface, continue the treatment process. Final biological treatment occurs in two vertical flow wetlands, one indoors and the other outdoors. Disinfection with ultraviolet light completes the treatment before the wastewater flows through the pond to the reuse system.
After treatment, effluent is disinfected and pumped to the Biolarium pond. The pond and waterfall visually demonstrate the quality of the treated water, which is utilized to maintain the lush plantings in the Biolarium space and the exterior landscaping. Much of this water seeps back into the earth to replenish the aquifer from which it was drawn.
El Monte’s engineered wastewater treatment system uses natural processes to provide advanced treatment within an aesthetic experience. The high-quality effluent it produces consistently meets tough discharge requirements. For example, the biochemical oxygen demand and the total suspended solids are consistently less than 5 mg/L, and total nitrogen is less than 10 mg/L.
One of the most unique things about El Monte’s Living Machine system is that guests, by experiencing wastewater recycling in a way that is easy to appreciate and understand, gain greater awareness of the effectiveness of wastewater recycling.
Stormwater Reclamation
El Monte’s Living Machine is designed to capture virtually all site runoff, treating and storing it for beneficial site uses. Rainwater and stormwater are collected through an extensive system of roof gutters, drop inlets and underground drainage pipes. The water flows to a lift station designed to keep pace with peak rain events. Rainwater is then pumped up to a storage and treatment system.
Rainwater pumped from the lift station flows into the storage tanks by way of a solids screening system. Water from the 20,000-gallon storage tanks is circulated through an advanced wetland system that provides high levels of treatment with minimal footprint and energy. The overall system design allows for treatment efficiency, yet it remains very simple.
Treated stormwater is used to offset evaporative losses and provide flushing water in the landscape’s cascading pond system. Water flushed from the ponds is filtered and used to irrigate the large grassy circle surrounded by 100-year-old cottonwood trees in the middle of the spa grounds. High in nutrients, the flushed pond-water acts as fertilizer for the grass and trees. In short, the treated stormwater serves the dual purpose of controlling pond nutrient buildup and moving these nutrients to the plants that need them.
Installing and Maintaining
The Living Machine has been on the market since 1995. When used in a simple form, it is competitive in price with other onsite wastewater treatment systems. Living Designs Group primarily works on the design but also provides some construction assistance and operational supervision. Local constructors are typically hired to install the system.
In most cases, the Living Machine is built with the facility itself. However, if it’s added to an existing facility, the installation will not interrupt the functioning of the business. The length of the installation process can vary, depending on many factors, but it generally takes anywhere from one to three months. The system is automated by the use of a control computer. Operational checks require about an hour a week, and routine maintenance averages less than an hour per week.
The Wisdom of Decentralization
Onsite wastewater systems are essential where centralized water and wastewater systems are not available. Decentralized systems can be adapted more easily to local conditions, making wastewater reuse far easier to implement—not to mention more cost-effective. Proper decentralized water and wastewater planning, design, and management are crucial for the success of any decentralized system. Each location has specific needs, opportunities, and restrictions, and these have to be identified and considered when developing a management plan or a design recommendation.
The incorporation of water reuse by integrated management systems may be the only key to development in areas with limited water resources. Ecologically, this makes good sense as well. Typically, communities require no more than 5% of source water for potable uses. A large percentage is typically used for irrigation purposes, which can be supplied by reclaimed wastewater or stormwater. Such practices greatly reduce any negative impact on water resources caused by development.
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Public Awareness
Learning about wastewater and stormwater recycling helps people understand, appreciate, and make the best use of their water resources no matter how apparently plentiful the water supplies appear to be. Where water supply is short, ecologies and landscapes can be created or sustained by irrigating with treated effluent. Even where rain is plentiful, treating stormwater in wetland environments creates habitat and beautiful landscapes. The creation of these green spaces, and of habitats that incorporate native species, can go beyond the reduction of impact and be restorative to the community and the planet.
The growing recognition of the environmental impacts of stormwater runoff and the importance of water conservation has placed stormwater management systems at the core of any sustainable development plan or project. Functional and beautiful stormwater management systems, where runoff can be stored and treated, are a reality with aquatic or wetland system designs such as a simplified version of the Living Machine. Rainwater collection systems can be built for individual buildings or clustered developments and can be part of a larger integrated water management program. While many communities and developers consider stormwater management a liability, rainwater systems can create valuable green space and habitat by capturing water for irrigation or domestic water supplies.
By utilizing an integrated ecologically based approach to water management at El Monte Sagrado Living Spa and Resort, the developers received functional and aesthetic enhancements as a part of their costs. Beautiful to look at, these systems provide reusable water to offset consumption in the dry climate. Guests also benefit by gaining an understanding of the processes behind wastewater management and its impact on the environment.
DAVID MACIOLEK, PE, is director of engineering, Living Designs Group, LLC.
OW - May/June 2006 |
