Underground evolution

Non-destructive drilling techniques are increasing their efficiency as time goes by and are being adjusted to engineering needs in large urban centers. But works are not enough to ensure their wide use in the country

Potable water and efficient sewage collection are indicators of country development. These services work as a parameter to follow the quality of life of a population and—if they are efficient—help to reduce health expenditures. But although public managers are planning targets for this area, the scenario of sanitation in Brazil continues to concern and requires more efficient actions to go ahead.

Data from the National System of Information about Sanitation (SNIS) based on the year of 2013 showed that only 48.6 percent of Brazilian people had their sewage collected and an even lower quantity (39 percent) had sanitation treatment. In practical words, this means that 107 million inhabitants throw almost 6 billion cu.mt. of untreated sewage directly into the environment, worsening the contamination of water sources. “Public costs with health are high to treat diseases that come from contamination of water and sewage. These expenses could be avoided if we had more investment on canalization, disposal and treatment of effluents”, says Edson Peev, senior engineer from Herrenknecht do Brasil.

This situation would obviously hurry measures, but this does not happen. According to a study developed by the Confederação Nacional da Indústria (CNI), these services should attend the whole population until the year of 2033. But to achieve this target in that date it would be necessary an investment of R$ 15.2 billion per year. And the historic investment average in these services is however very low, approximately R$ 7.6 billion per year between 2002 and 2012.

At this pace, reach the target will be quite complex. But the study points also that—if no impacting changes in the current policies of sanitation happen—the universalization of these services in Brazil will occur only in 2054. Main obstacles are the excess of bureaucracy, the lack of efficiency and the problems of management, that rise costs and charge prices and services.

Another alarming factor is that 37 percent of the treated water is lost. It leaves the plant but does not reach the consumer due to the use of obsolete equipment, lack of precision in the equipment, precarious situation of distribution networks, lack of maintenance and irregular connections. The result is that only R$ 63 from each R$ 100 of treated water are billed by the concessionaires.


In addition to the high investments there is also a technical approach, since it is also necessary to carry out the works without interfering in the environment and in the traffic of large cities. This is a task where Trenchless Technologies (TT) are an important supporter. Using differentiated techniques and equipment to install, repair or replace underground networks, these methods result in lower social impact since they avoid removal of paving, excavation of material and transport to disposal areas, for example.

According to Sérgio Palazzo, member of the executive subcommittee of the International Society for Trenchless Technology (ISTT), works of installation of sewage and gas networks will be the largest users of TT in the next years. Piping refurbishment, however, will not keep the speed that was expected at the beginning. As a first step, new networks will be built and the sewage irregularly discarded will be treated. “The market of natural gas will continue to grow, mainly because Petrobrás will not be the main player, opening chances for international investors”, observes Palazzo. “In Brazil, natural gas was developed in a reasonable way, but is still in a low level”, points him, calculating that 99 percent of the applications of Directional Drilling are carried out for gas networks and that 100 percent of micro-tunneling applications are for sewage projects.

In addition, water networks built with cast iron pipes before the 70s have currently problems of scaling and corrosion. Palazzo also tells that some Brazilian cities loose an average of 35 percent of treated water that flow through damaged piping. With the increase of TT they may be repaired or replaced using the existing piping as a guide for insertion of the new network, to prevent damage to adjacent structures and new interferences.

According to estimations of Flávio Leite, general manager of Vermeer Brasil, there are currently 150 companies specialized in non-destructive directional drilling equipment in Brazil, being 70 percent concentrated in the Southeastern and Southern regions. In the area of micro-tunneling there are approximately 20 companies, most located in the same regions. The manufacturer has supplied more than 250 machines of non-destructive drilling in the whole country.

On the other hand, Peev, from Herrenknecht, adds that the economic recession and the water crisis caused a stoppage in the investments of the Companhia de Saneamento Básico do Estado de São Paulo (Sabesp), with direct impact in the reduction of expansion projects of water and sewage networks. “Sabesp is the largest investor using non-destructive methods in the area of sanitation in Brazil, but the expansion of its networks is slower than we expected”, points the expert. “Although it has many projects, the Companhia Estadual de Água e Esgotos (Cedae), concessionaire in the state of Rio de Janeiro, is also with investments stopped in that area due to the same reasons.”