The City of Santa Cruz, Bolivia, and the surrounding areas has a population of 1.6 million. Santa Cruz is designed in eight concentric rings surrounding the city center. As the city has grown, development has moved out through these ringed areas and beyond. A municipal sewage treatment plant serves the innermost three rings of the city. The remaining areas use substandard onsite septic systems for wastewater treatment. These onsite systems are costly, inefficient and pose a concern for the quality of the city's groundwater and community health.
The problem of wastewater treatment is increased by the recent heavy commercial and residential development in Santa Cruz. This development is a result of inexpensive labor, reduced taxes on Bolivian-made goods, the country's central location in South America and new financing programs recently initiated in Bolivia.
The introduction of home financing programs in Bolivia (although expensive with loans rated near 18 percent) has greatly increased the demand for residential development. Residents, who previously lived in expanded or adjacent homes with extended family, now are able to consider the purchase of separate housing for their individual families. This has further spurred a development boom in the outlying areas, beyond the reach of existing municipal sewage treatment.
Many large-scale multi-use developments are in the planning stages in Santa Cruz. One example is a 5,000-lot housing plan that will include a country club and shopping complexes just outside the 8th ring of the city. Without the availability of sewering in this area, a new wastewater treatment solution is critical to continued growth. Currently, stone and pipe leachfields and seepage pits are used for wastewater treatment in the outer areas of Santa Cruz. The seepage pits are dug and lined with brick by hand labor, taking up to two weeks to build. Construction is dangerous and results in many accidents that are sometimes fatal. With depths of anywhere from four to 10 meters (13 to 33 feet), these pits commonly extend below the water table. This practice has the ongoing potential to contaminate groundwater in the area.
Wastewater Handling Change
Groundwater contamination also results from the emptying of wash basins and sink water, used for bathing and washing clothes and dishes, into yards and in some cases directly into the street. Poor street drainage in some areas of the city creates standing water problems. Surface effluent also can be found along streets and in the canals of some communities. This poses a potential health risk to the surrounding public.
A strong effort to improve conditions by local developers and community officials in Santa Cruz is beginning to change wastewater handling procedures. When a group of community leaders recognized that defining specifications for local water use and wastewater management was critical to the continued development of the city outside the sewered areas, it began to look for outside assistance. Due to the small size of most home and business lots, system-sizing guidelines and technology that would be effective and could be installed in a very limited area was sought. Key to the initiation of this effort was Vincent Jofre, formerly with Bolivia Customs; Humberto Nazra, an engineer for the city of Santa Cruz; and Hugo Lozada, a financial analyst. These men recognized that the increasing development in and around the city of Santa Cruz posed a threat to water quality and health safety. With new development already underway, they knew that fast action was needed to uncover effective wastewater treatment options.
To gather information and find a technological solution that would enable the future development of Santa Cruz, Jofre and Nazra contacted Infiltrator Systems, Old Saybrook, Connecticut, in the summer of 1999. They scheduled a meeting in Los Angeles, California, with Mark Grady, then technical services manager for Infiltrator Systems.
"Our goal was to explore how chamber leaching systems, combined with other new technology, could improve wastewater treatment and protect drinking water resources while allowing continued development in the outer areas of Santa Cruz," Jofre said.
"They contacted us about chamber technology due to the small building lots in the city and because they had read about the ease of installing our products from both a time and labor perspective," Grady said.
Hours were spent discussing the technical aspects of septic systems and how chamber technology could work in this land-constrained area.
As follow-up to the Los Angeles meeting, Infiltrator Systems agreed to ship 400 chambers to Santa Cruz to be used in demonstration projects for other health officials, engineers and developers. Grady also agreed to travel to Bolivia to work with Jofre, Nazra and Lozada to assess water usage and determine sizing criteria for the new wastewater treatment systems. Grady analyzed city water records from Santa Cruz and found that the average water usage was 30 gallons per person per day.
"This is far less than the 45 gallons per person per day used in the United States," Grady said. "This enabled us to lower the sizing specifications for household wastewater systems specifications to reflect the reduced flows."
The difference in water usage can be explained by the fact that a typical home in Bolivia does not have dish or clothes washing machines. In addition, water usage habits such as the number of showers per week per person and how food is cooked vary greatly as compared to the United States.
Grady and Nazra developed system sizing for different villages in Santa Cruz. Grady then conducted an installation demonstration in one of the city's villages of a residential chamber system. In that system, nine chambers were installed in two leachfield trenches.
"Prior to installing the demonstration system, we conducted a site evaluation to determine a suitable placement for the leachfield," Grady said.
Due to restricted space on the site, the only available space for the new two trench chamber leachfield was on each side of a sidewalk in front of the home. This was not a typical installation for chamber technology. However, it demonstrates the flexibility that chambers can provide.
In the demonstration system, effluent bypasses the old seepage pit and flows from the septic tank into the chambers where it infiltrates into the soil. The modular plastic leaching chamber offers twice the infiltrative capacity in the same space as a 24-inch stone and pipe septic leachfield installation. The chamber is 15 inches wide and features continuous louvers that wind fully around the sidewall, offering maximum infiltration of effluent into the soil. The chamber bottom is completely open, maximizing percolation downward. Grady explained the installation procedures and the advantages of chambers to architects and engineers who attended the event. Installation instructions were translated into Spanish for those attending.
In August of 1999, as a result of the initial demonstrations by Grady and further discussions with Andrew England, marketing manager for onsite septic at Infiltrator Systems, Jofre had an idea. Recognizing the wastewater management needs and the opportunities in Santa Cruz, Jofre started Soluciones SÚpticas (Septic Solutions).
"The goal of the new company is to solve the wastewater issues of Santa Cruz by bringing Infiltrator chambers and other new wastewater management technology to Bolivia," Jofre said. Jofre plans to expand his wastewater management technology to other cities in Bolivia and throughout South America in the near future.
England traveled to Santa Cruz again in September to exhibit his technology at the international trade show ExpoCruz 99. "This 10-day show brought 17 countries and more than 300,000 people to Santa Cruz where exhibitors from the construction equipment, building supply, agricultural and manufacturing communities displayed new products to the South American marketplace," England said.
At the show, England and Jofre met with developers and construction company owners to discuss wastewater solutions specifically related to sites they were developing. "The presidents of these companies were so excited about the prospect of having an easy-to-install, cost effective and environmentally-sound wastewater solution, they arranged meetings for me with their company engineers before I left Santa Cruz," England said.
Following the trade show, England and Jofre met with the city developers to specifically discuss the use of chambers for future onsite systems throughout the city. They also completed a cost comparison study that showed that the chamber system was cost-competitive with the traditional onsite systems installed in Santa Cruz.
"This is just the beginning of a long relationship with this city that we hope will expand throughout South America," England said. "It also is the beginning of a move toward environmental awareness and protection. The key players in Santa Cruz have taken a solutions-based approach to their problem and it will pay off for the entire city through improved health, housing and safety," England said.