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Exploring New Frontiers-Erosion Control Patrol Goes International
Adapted from an article written by Jason Cole in the July/August 1998 issue of Erosion Control Magazine.
For decades, many South American countries have been pushing back the boundary of the rainforest to satisfy the demands of their growing populations. While the preservation of plant and animal species and other media-friendly environmental issues have come to the attention of policymakers, the problems associated with erosion from development have taken a backseat. Unfortunately, the unique and delicate nature of the rainforest ecosystem may experience the effects of uncontrolled erosion more drastically than the domestic urban and rural areas already benefiting from proper erosion control practices. However, some South American countries have begun to realize the environmental and economic impact of uncontrolled erosion. They have turned to the international community for information and expertise.
"The driving force behind this new awareness is simple economics," explains Chuck Austin, president of Revegetation Exchange, Inc. "When buildings are in danger of falling off a hillside, and roads are constantly being rebuilt because they keep washing out, eventually you figure out that in order to avoid these costs you need to control the erosion." These economic factors have provoked legislation that will require developers to take the necessary precautions and control the erosion on project sites. As the stakeholders begin to look for solutions, they are finding the international community to be a knowledgeable and helpful source of information. According to Austin, "The Internet and other sources make information readily available, and people are getting the answers they need."
Recently, Austin had the chance to apply his expertise in uncharted territory when he was asked to participate in a slope stabilization project in the rainforests of northern Peru.
Project Site and Background
Several project areas, each between one and three acres in size with slopes ranging from 1:1 and 1:1.5, are scattered throughout a 740,000 acre site in northern Peru near the Ecuador border. Providing nearly 1/3 of Peru's domestic oil production, this site, owned and operated by a large United States oil company, has been active for roughly 25 years, yet no more than 5% of the site is actually developed. Areas that have been cleared and prepared for development, especially near slopes, have created potentially costly erosion and sediment movement problems. The project sites, chosen primarily because of recent development activity in the area, were to be used as testing grounds for the reliability of erosion control applications in this environment.
Since Peru is only a few degrees from the equator, it rains almost daily and the intense sunlight offers little relief to new plant growth. The ground cover consists of a thin layer of topsoil made up of organic waste matter from the jungle's dense canopy of trees that sits on top of a thick bed of washed-out clay. To further challenge project managers, the remote nature of the site limited the choices and amounts of application material to be used in the erosion control efforts. "The actual impacts of erosion on the site have been relatively minimal so far," explains Austin. "However, the government and the company have realized that any disturbance of soil can be a potentially big and costly problem." The primary goal of this project was to test the strength and reliability of standard erosion control applications in this new environment, as well as to eventually develop and train a team of on-site workers who could prevent erosion in areas of new development before it becomes an economic and environmental liability. In order to effectively stabilize these slopes and develop a long-term erosion control plan in this environment, project managers had to tap into their years of experience and creatively explore the most practical and efficient solutions.
Into the Heart of Darkness
"I had spent some time working with the oil company and some consulting firms they had hired trying to learn about the soil and weather conditions down there and discussing the applications that might be most effective," explains Austin. "We looked at everything from hydraulic products to blankets, from roll-on products to synthetics, and they all probably would have worked. It eventually came down to concerns about shipping the product - because of the location, freight costs could be high.." Due to their extreme bulk, Austin estimated that only 3 to 4 acres worth of blankets or roll-on products could be shipped for the same cost as 12 to 13 acres worth of a bonded fiber matrix (BFM) product.
Soil Guard BFM was chosen as the product application best suited to the unique needs of the project. "I have had a lot of experience with BFMs, and I had seen the product perform in a variety of scenarios, so my confidence in the material was very high." Once decided, the Soil Guard, seed, and a Finn T-60 hydroseeder were ordered and sent on a two to three month journey to the project site in Peru. Originating from Houston, TX. the materials and equipment were shipped to mouth of the Amazon River in Brazil, then loaded onto barges and moved up the river to the Maranon River, to a smaller tributary, and then eventually to the project site.
Without having previously visited the site, Chuck Austin quickly realized upon arrival that some basic factors had been overlooked. "Going into this project relatively blind, we did not recognize the necessary need for soil amendments or fertilizers," explains Austin. "It was not until we got down there that I realized how few nutrients were in the soil." Proceeding with the first test applications, it was not long before some of the potential problems Austin had identified regarding limited soil nutrients became apparent. "The material cured well and we did get some early plant growth, but as soon as the vegetation started to establish deeper roots, the plants died off due to a lack of nutrients," says Austin. "With the extreme temperatures and moisture, the Soil Guard began to degrade very rapidly, allowing the next major rain event to completely wash the slopes." Dismayed but not ready to give up, Austin ordered additional materials and patiently waited to take another crack at the project. "For the second attempt, we brought soluble humates, a lot more seeds, and we also decided to transplant some native plants from the surrounding area to further increase our chances of success," added Austin.
With work completed in November 1997, recent reports from the jungle indicate success, as indicated by this photo from 2000.
"The reports say that the slopes are still holding up, and we've got some good vegetative growth," says Austin. The next step will involve setting up an environmental division of the oil company that will have sufficient training, materials, and equipment to perform erosion control activities on a day-to-day basis if necessary. "The ultimate goal of this project went way beyond securing a few slopes," says Austin, "We are trying to spread the word about the effects of erosion and educating people about possible solutions to these problems."
There is no doubt that the ability to communicate quickly and easily has already brought enormous dividends to the erosion control industry as a whole, but this is only the tip of the iceberg. "The growth of erosion control awareness has really been accelerated by the technology of communication," says Austin. "There is so much information available now that new ideas are beginning to spread and really influencing the development of the industry." While impressed by the abundance of new techniques, products, and services at this year's IECA show, when asked what he expects to see in coming years, Austin replied, "We ain't seen nothing yet!"