Merging sustainable development with wastewater infrastructure improvement on the U.S.-Mexico border.

Introduction

The World Health Organization (WHO) declared the 1980s the "International Drinking Water Supply and Sanitation Decade." Seven years after the end of the decade and billions of dollars later, nearly two billion people continue to live in conditions short of WHO's goals, and many projects that have been built lie abandoned ([ILLUSTRATION FOR PHOTO OMITTED] on page 9) (1). What happened? While there are numerous reasons that wastewater projects in developing nations did not meet the goals or needs of the communities they were intended to serve, many failed because they overlooked basic principles of sustainable development, which in a few short years has become a reigning concept in the field of international development. A recent proposal by a consortium of private and nonprofit companies to design and implement a combined wastewater treatment/microenterprise development on the U.S.-Mexico border illustrates basic concepts of sustainability and the sort of progressive new thinking that is increasingly seen as necessary for long-term survivability of environmental infrastructure improvements.

Sustainable Development Defined

What is sustainable development and how do you increase the sustainability of an environmental infrastructure - or, for that matter, of any infrastructure or project? The World Commission on Environment and Development defines sustainability as "meeting the needs of the present without compromising the ability of future generations to meet their own needs" (2). Sustainability implies that the needs of a population and the flow of resources needed to support them are in dynamic balance (3). With these principles in mind, one can explore how the concepts of sustainability may be applied in developing communities that historically lack wastewater infrastructure throughout the world.

The U.S.-Mexico border is a prime example of such an area. Passage of the North American Free Trade Agreement (NAFTA) created the Border Environment Cooperation Commission (BECC) and the North American Development Bank (NADBank) to respectively approve and finance environmental infrastructure projects within 100 kilometers on either side of the U.S.-Mexico border. Both organizations aggressively promote sustainable development, repeatedly citing sustainability as a precondition for project certification. Projects proposed to the BECC can request special consideration and "high sustainability" status based on a list of program components (4). A partial list of those components includes

* principles of ecosystem management,

* recycling (of residuals into salable products),

* habitat preservation or enhancement,

* creation or improvement of parks,

* job creation,

* improved environmental and health services, and

* education programs.

Sustainable Development in Practice

Even the most well-intentioned project that includes all of the above-named components and more will fail, however, if its basic nature does not reflect the needs and desires of the people who will manage it. In recognition of that fact, BECC claims to prioritize those projects that demonstrate high levels of community participation in both the planning and implementation stages. Their logic is unassailable; since the community ultimately assumes responsibility and ownership of projects, organization of community members and incorporation of their suggestions from the earliest stages of project planning are essential. While public support should be high if the project is perceived as promising community benefits, continued community involvement and the project's chances for long-term success are directly tied to how those benefits in fact develop over time. Training participants in maintenance, and educating community members about the environmental, health, and economic benefits that stem from the project are seen as similarly critical to acceptance of, support for, and the ultimate overall success of a project.

In the area of environmental health, however, benefits are often subtle and not immediately apparent. Instruction in basic sanitation and its relationship to disease and quality of life is one method of instilling a sense of benefit from a wastewater project, and such instruction should be promoted at every opportunity. Because it is women who usually care for sick children, they have a critical role in the dissemination of information about the health benefits of improved sanitation; every effort should be made to solicit their involvement. Elementary school teachers are another potent force for disseminating information in developing countries and can be invited to observe project development, tour the completed facility, and use it as a destination for field trips for their students, who should be encouraged to pass on what they learn to their parents at home.

The Role of Constructed Wetlands in Sustainable Development

Constructed wetlands are an innovative technology for wastewater treatment, and offer multiple benefits to developing communities. As a nonmechanical system built with locally available labor and materials, they provide an affordable way for communities to provide environmental protection, reduce risk of direct contamination and disease transmission, and preserve vulnerable drinking water supplies. Subsurface-flow wetland systems provide these benefits by maintaining all flow within a solid stone matrix, thus reducing odor and mosquito breeding opportunities [ILLUSTRATION FOR FIGURE 1 OMITTED]. Emergent vegetation grows hydroponically in the stone media, extracting excess nutrients from the wastewater for incorporation into plant matter and translocating oxygen to a root mass that requires oxygen to survive. Additionally, the roots and living and dead plant matter provide a rich substrate where aerobic and facultative microbes thrive while consuming contaminants in the wastewater.

Care is required in choosing plants for a constructed wetland. Since introduction and possible escape of new species must be avoided, and since invasion by native wetland species is usually inevitable, only endemic species should be used. If livestock graze nearby, some means of excluding them must be provided to protect the vegetation.

To ensure that wetlands technology will be supported by the community, initial implementation of small pilot wetland systems using a portion of the wastewater flow is recommended. If the pilot systems are successful, additional wetlands can be installed to eventually treat greater quantities of wastewater.

But while improved health and environmental benefits are powerful motivators, economic considerations, particularly in developing countries, are more often the critical factors in a project's implementation and success. For that reason, the Naco Constructed-Wetland/Microenterprise Project (NACWEMP) sought to tie wastewater infrastructure improvements to microenterprise opportunity development. A brief history of environmental and health challenges along southeast Arizona's border with Mexico, and a review of how those challenges have been addressed, provides a context for understanding NACWEMP's evolution and illustrates how the project will satisfy BECC's call for high sustainability.

Environmental Health and the Southeast Arizona-Northeast Sonora Border

A 1993 agreement between the United States and Mexico established the Commission for Environmental Cooperation (CEC), BECC, NADBank, and other NAFTA-related environmental organizations. The various binational entities have agendas that specifically encourage public input on programs to preserve, protect, and enhance both sides of a border whose two economies have long been socially and economically intertwined. Pollution flows without regard for artificial political boundaries. Thus the existence of the new commissions provided nongovernmental organizations (NGOs) in the border region, such as the Bisbee-based Border Ecology Project (BEP) and Agua Prieta-based Enlace Ecologico (Enlace), with new opportunities to expand their cross-border cooperation in addressing the environmental concerns of communities on either side of the border.

Environmental problems that have concerned both Enlace Ecologico and the Border Ecology Project are numerous in this part of the border region. Mexico's copper industry is based in northeast Sonora, and emissions from smelters in Nacozari and Cananea have been identified as the source of regional air pollution. A former Phelps Dodge smelter in Douglas, Arizona, is a proposed Superfund site. Further down-gradient, in Agua Prieta, Sonora, both heavy metals and sulfates appear in local wells.

The fight against problems such as these, which can originate on and affect either side of the border, obviously benefits from a unified approach. The Border Ecology Project and what is now Enlace first collaborated on analyzing the impacts of regional copper smelter emissions on Mexican agricultural production. This research was a supporting reason for Mexico's signing of a 1987 binational treaty that limits copper smelter emissions in the U.S.-Mexico border region.

A unique characteristic of the U.S.-Mexico border is the extreme difference in wealth and power of the two countries. The relative abundance of resources that U.S. entities possess represents a particular challenge to NGOs operating there; the fear is that well-funded U.S. entities will have disproportionate influence over operations of supposedly bilateral groups such as BECC and NADBank. For this reason, prime directives of BEP and Enlace have been to increase participation of Mexican NGOs and to strengthen the local municipal and rural capacity for gathering and disseminating information and increasing public participation within cross-border and Mexican localities (5).

One primary organization through which BEP and Enlace pursue that goal is the Northeast Sonora/Cochise County Health Council (NSCCHC). NSCCHC's board includes prominent environmental and health advocates from both sides of the border. Its functions have included promoting community participation at BECC meetings and specific regional projects such as a Douglas environmental health project that:

* conducts assessments of environmental and health problems and strategies to combat them,

* promotes water and air quality monitoring, and

* conducts epidemiological testing.

Interdependence - a key principle of sustainability - is stressed in all of these undertakings. NSCCHC has links to the Pan American Health Organization. Funding and in-kind contributions for BEP-Enlace collaborative work have come from charitable foundations as well as from the U.S. Agency for International Development (USAID) and the Arizona Department of Environmental Quality for the actual investigations.

Since the inception of BECC, BEP has urged strict oversight and a high level of community input to prevent BECC from certifying projects that were "good for contractors and not good for poor border residents." BEP has also warned that NADBank would be reluctant to invest resources in projects that may be canceled because of public discontent (5). Driven by those concerns, BEP and Enlace collectively participated in developing BECC rules of procedure, criteria for project approval, and local outreach efforts. In so doing, they gained experience critical for obtaining approval and funding of an environmental infrastructure project in their own back yard: an expanded wastewater treatment facility for Naco, Sonora.

The Naco, Sonora, Water Supply and Wastewater Treatment Project

Plans to renovate the sewage treatment plant at Naco, Sonora, developed in the wake of a long history of inadequate sewage treatment dramatically punctuated by several high-profile incidents in which sewage overflows from Mexico coursed into U.S. washes. Enlace Ecologico initiated the wastewater treatment project by securing support of the International City and County Managers' Association who developed a design for a new water supply system and the overhaul of Naco's antiquated sewage pond system. The expanding web of participants grew to include representatives of the U.S. and Mexican governments, private foundations, NGOs, academics, and the Naco community.

Broad-based planning begat broad-based funding support. Mexico's National Water Commission contributed $350,000 to the project. A $300,000 grant from the U.S. Environmental Protection Agency left only 22 percent of project costs uncovered. The openness of the planning process and the ecological benefits of the treatment system which emerged from it - wastewater reuse, reduced reliance on valuable groundwater supplies, an equitable fee structure, and the introduction of water meters - were all recognized and applauded by U.S. and Mexican border commissions. The last money came in December of 1996, when Naco, Sonora, a tiny town competing with sprawling cities like Tijuana and Ciudad Juarez, became the first border community to be awarded NADBank financing.

The Naco Constructed-Wetland/Microenterprise Project

Shortly before actual construction of the new facility was scheduled to begin, Enlace Ecologico contacted Environmental Compliance International, Ltd., (ECI), Arizona-based specialists in wastewater treatment, to discuss incorporating constructed wetlands into the facility. Enlace Ecologico's choice of constructed wetlands and its decision to begin with a demonstration facility maintained by community volunteers were consistent with basic principles of sustainability: environmental enhancement through habitat creation and improved wastewater quality, community participation, and modular construction.

By working with both BEP and Enlace Ecologico, ECI gained essential cooperation from local officials and governmental authorities. Additionally, several important considerations from the community's perspective were brought to ECI's attention:

* Unemployment and underemployment were largely unaddressed.

* Partially treated effluent had been previously distributed in open furrows to irrigate a languishing nursery of cottonwood trees adjacent to an unprotected children's recreational area.

* A constructed wetland in Sierra Vista, Arizona - 35 miles away - was receiving considerable attention in the environmental, birding, and tourism communities. Could Naco not eventually develop a similar project?

To address those concerns, ECI recruited experts in economic botany from Drylands Institute to assist with the development of NACWEMP, a community-based plan for integrating low-technology wastewater treatment with financially remunerative reuse activities. The proposal to build NACWEMP, submitted to the Commission for Environmental Cooperation's North American Fund for Environmental Cooperation in the spring of 1997, sought funding to build a subsurface-flow constructed wetland that would treat wastewater and simultaneously serve as a platform for three innovative reuse efforts.

Agricultural Reuse

Many high-value crops thrive on effluent. Particularly in arid climates, effluent is widely used as a source of irrigation water. While any wastewater treatment project can be made more sustainable through appropriate use of treated effluent, constructed wetlands offer the unique advantage of using the treatment medium itself to grow valuable agricultural products directly on site.

Mesquite: A Formerly Overlooked Resource

Mesquite (Prosopis, spp.) was identified early on as a preferred NACWEMP crop. Mesquite is a riparian tree that also thrives under arid conditions. It has been grown hydroponically and has great potential economic value (6,7). Markets for mesquite wood and pods (a source of flour for human consumption and cattle fodder) exist in nine northern Mexican states with pod utilization the focus in eight of them. Only in Sonora does the nonrenewable harvest of wood predominate, a trend exacerbated by the growing U.S. market for mesquite (8). Severe declines in Sonoran stocks of wild mesquite have been noted (9).

The ease of establishment and rapid growth of mesquite, as well as its tolerance of saturated conditions make it a good candidate for inclusion in constructed wetlands projects wherever it is endemic. Several characteristics of mesquite make it appropriate for large-scale cultivation. Mesquite has high genetic variability and is easily propagated; because of these characteristics, it lends itself to selective breeding and hybridization (6,8). Its deep roots make it drought tolerant, yet it is highly adaptable and thrives under moist conditions. While studies have yet to be completed on the increased growth of mesquite on high-nutrient wastewater, growth rates with potable water are initially from 4 to 5 feet per year. The tree goes on to bear fruit throughout its approximately 100-year life. Pod yields range as high as several thousand kilograms per hectare per year. All of these characteristics make mesquite-based microenterprise a potentially valuable component of wastewater infrastructure improvement.

To conserve space and derive maximum benefit from the wetlands, a system for planting mesquite seedlings directly in the wetland media was devised. The system allows for easy removal and eventual transplanting. The "Mesquitalito" (patent pending), or "tiny mesquite grove," converts a subsurface constructed wetland into a high-nutrient nursery for riparian trees [ILLUSTRATION FOR FIGURE 2 OMITTED]. The languishing grove of cottonwood trees, formerly under irrigation with semitreated effluent, seems like a natural place to begin reforestation with mesquite seedlings; however, ultimate use of the trees will be determined by the community of Naco.

Gourds: A Value-Added Resource

Gourds represent another innovative crop well-suited for effluent irrigation. Gourds are water intensive crops traditionally grown by indigenous people of the Sonoran desert region. Because they are not a food crop, water quality considerations are reduced. Dried gourds of various shapes and sizes have historically been used for many purposes, which suggests high potential for added value. The crafts market, a significant economic sector in many border communities, represents a large potential market for dried and finished gourds that can be used as kitchen utensils and vessels for water and storage.

Naco's fortuitous location near southeast Arizona, one of the premier U.S. destinations for bird-watchers, and Naco's desire to lure tourists from nearby Sierra Vista and its wetlands, however, suggested a more targeted use for Naco-grown gourds. Representatives of the Audubon Society, the Nature Conservancy, and the owner of Tucson's Wild Bird Store (one of a chain of over 400 such specialty birding stores) agreed to collaborate on a plan whereby "Birdhouse Gourds" (Lagenaria sp.), formerly used in the corn fields of Native Americans to attract avian insectivores, and still favored by bird fanciers for use in construction of birdhouses, will be grown, dried, and sold across the border or fashioned locally into finished birdhouses.

Gourd growing and birdhouse construction represent particularly promising enterprises for school groups or women's and girls' training groups. Training sessions and workshops will be scheduled to build local capacity to produce and market the items. Organizations like Pueblo to People (which markets crafts of indigenous people by catalogue) are another potential outlet for gourd crafts. Confident of eventual funding for NACWEMP, Tucson's Wild Bird Store, citing a shortage of birdhouse gourds in the domestic market and their recent replacement by inferior, injection-molded replicas, has signed a letter of agreement to purchase finished birdhouse gourds and to market them through the Wild Bird Store mail-order catalogue.

Apiculture: Merging Ecological Health with Economic Opportunity

Apiculture, or beekeeping, is yet another way of linking wetland vegetation health with microenterprise. A program to introduce beekeeping, developed and administered by the local beekeepers, will be used at Naco to integrate a third microenterprise with environmental improvement. Beekeeping simultaneously supplements the population of pollinators needed for good ecosystem health, provides opportunities for vocational training, and introduces another potential alternative income source to the community. Honey can also become an important dietary alternative for the community as well. In the case of Naco, two to three hives are projected for the introduction of apiculture to the community.

A review of the literature suggests that sanitary concerns regarding the proximity of open sewage lagoons to the beekeeping operation are undeserved. With the exception of osmophilic yeasts, honey is not a good medium for microbes. Burgett reports that because of its low moisture content (less than 18 percent), low pH, and tendency to produce its own hydrogen peroxide, honey "does not support the vegetative life stage of any bacterial species" (10). While one researcher did suggest a link between honey and Clostridium botulinum, the latter is a ubiquitous soil-based organism, and no further evidence of its presence in honeybee hives has been reported in the literature. Indeed, so effective is honey at retarding microbial growth, that it has been used as a general antiseptic and specifically for preventing infection in burn victims (11).

Hives at Naco will be located at the sewage treatment/constructed wetland complex, thereby reducing the likelihood of problem encounters with the public while providing the bees ready access to dependable pollen sources. As with mesquite and gourds, training sessions and workshops will be scheduled to build local capacity to produce and market honey. As a safeguard, screening for bacteria, viruses, and Clostridium botulinum will be conducted to demonstrate that the honey meets appropriate U.S. and Mexico hygienic standards. Eventually, it is hoped, beekeeping will become more popular in Naco. Alfalfa is widely grown in nearby fields, and potential for a real market in honey exists if interest in the pilot project grows.

Summary

Developing sustainable features for a wastewater improvement project requires creativity, commitment, and flexibility on the part of those wishing to implement the technology as well as on the part of the community being served. Choosing the best mix of agricultural products to grow and market should be a well-researched effort supported by the community. Revenues from microenterprise operations should be estimated conservatively, and nonmonetary benefits should be promoted at every opportunity. Although the time and effort required to solicit community involvement and to identify and develop project components that ensure sustainability are significant, the need to do so is essential. With major funding organizations such as BECC and NADBank now requiring such considerations as preconditions for project support, the former "bottom-up" strategy of sustainable development has come full circle and is now an essential "top-down" consideration.

Postscript:

On September 2, 1997, the Commission for Environmental Cooperation announced that it had awarded $55,000 for the implementation of NACWEMP. Results from the first year's endeavors will be submitted for publication in a future issue of the Journal of Environmental Health.

REFERENCES

1. Water and Sanitation Annual Report, July 1992-June 1993 (1993), Washington, D.C.: United Nations Development Programme-World Bank, p. 6.

2. Walter, B., L. Arkin, and R. Crenshaw (1992), Sustainable Cities: Concepts and Strategies for Eco-City Development, Los Angeles, Calif.: Eco Home Media Publishers, p. 63.

3. Barnett, D. L. (1995), A Primer on Sustainable Building, Snowmass, Colo.: Rocky Mountain Institute Press, p. 4.

4. Guidelines for Project Submission and Criteria for Project Certification (1995), Ciudad Juarez, Chihuahua, Mexico: Border Environmental Cooperation Commission, p. 17.

5. Coles-Ritchie, Marc (Winter 1996/1996), "Border Ecology Project Activities Review and Bibliography," Annual Review of Activities.

6. Karpiscak, M.M. (1973), Aspects of Thorn Development on Prosopis juliflora (Swartz), DC var. velutina (Woot.) Sarg., and Cercidium australe (I.M. Johnson), Master's thesis, Tucson: University of Arizona.

7. Felger, R. (February 1990), "Mesquite - A World Food Crop," Aridus, Bulletin of the Desert Legume Program of the Boyce Thompson Southwestern Arboretum and the University of Arizona, 2(1):1-3.

8. Silbert, M. (1988), Mesquite Pod Utilization for Livestock Feed: An Economic Development Alternative in Central Mexico, Master's thesis, Tucson: University of Arizona.

9. Simpson, B. (1977), Mesquite: Its Biology in Two Desert Systems, Hutchinson and Ross.

10. Burgett, B.M. (1990), "Anti-Bacterial Systems in Honey, Nectar, and Pollen," in Honeybee Pests, Predators, and Diseases, R.A. Morse and R. Nowogrodzki, eds., 2nd ed., Ithaca, N.Y.: Cornell University Press, p. 729.

Corresponding Author: Eric Ellman, Environmental Compliance International Ltd., P.O. Box 85073, Tucson, AZ 85754.