Law of Supply and Demand: As demand increases, the final price tends to increase. Generalizing the concept that dictates the functioning of the market, it can also be applied to basic sanitation (also business).

Whether the management is public, private, municipal or public, financial returns will always be a determining factor in the approval of urban wastewater collection and treatment works.

Art: Luciano Maciel/North Dakota

Business in Santa Catarina thrives due to the strong presence of technology industries and capacities in addition to the frantic pace of tourism. However, when looking at the demographics of the state, which has 295 municipalities, most of which are small, a contrast emerges. 242 cities (82% of municipalities) with a population of up to 25 thousand inhabitants.

The state has over 1 million people living outside the city limits of their respective municipalities. The section related to the number of inhabitants is strategic for understanding the dynamics of the introduction of sewer networks.

Required equation: number of inhabitants and financial return

The low concentration of residents and the isolation of living are factors that, as a rule, have always “struck” with the presence of investments in wastewater treatment plants.

The data confirms that according to the SNI (National Sanitation Information System), there are 207 municipalities in the state with zero sewer coverage and 246 cities with up to 25% coverage – still well below the set target. The legislative base in the field of sanitation should reach 90% by 2033.

The rationale is similar regardless of the type of administration responsible for sanitation in small towns. Both Kazan and the municipalities explain that it is not possible to install a sewage collection network to serve these municipalities, so the private sector is also not interested.

However, the problem also recurred in large cities. According to SNIS, when a sample of the 15 largest cities in the state is taken into account, sewage coverage averages only 38%.

Asked about the delay, Kazan (Companhia Catarinense de Águas e Saneamento), which is in charge of sanitation in 194 municipalities in the state, notes that the “boom” has been observed for 10 years. “Investments went to the highway, even to water supply, but they did not invest in sewerage.

Now they have resources, even from abroad, so much so that Kazan has resources from the French, Japanese agency, he already had resources with the World Bank. It took a long time, this is a recent need for our state profile,” says Casan President Roberta Maas dos Anjos.

Work becomes routine to make up for lost time

According to Kazan, 15 sewer works were completed between 2019 and 2022, and 17 more are in progress. During this period, coverage in municipalities served by the state-owned company increased from 26% to 31%. According to the company’s forecast, in 2027 the figure will approach 50%.

In Joinville, the state’s largest city, the system is operated by the CAJ (Companhia Águas de Joinville). By 2021, data showed only a 38% wastewater collection rate.

According to City Hall, the current percentage is 43%. According to the CAJ, the investment in 2022 is estimated at 155 million reais.

Big cities with small zip code

Two of the state’s 15 largest cities still have a sewer network index of zero. One of them is Brusque, with a population of almost 140,000 people, known for its companies and development. However, sanitation slipped.

Sonia Crespi from the mayor’s office specifies that the municipality started the construction of a sewer network in the main neighborhoods in the 90s, but the project has not progressed.

Since 2014, an individual cleaning system has been applied, in which residents use septic tanks and are controlled by the mayor’s office. Crespi says events such as public hearings and a bidding process are “scheduled for 2023,” but there is no timetable yet.

Another municipality that has an index of zero in the SNIS data is Tubarao in the south of the state. However, according to Tubarão Saneamento SA, coverage is already much higher than the 2020 SNIS data.

“In December 2022, the percentage of sewerage coverage increased from 30.4% to 42.3%,” the company said in a statement. The municipality has an agreement that spells out the goals and provides coverage of 37% by February 2023.

Water supply and sewerage in hard-to-reach places “three times more expensive”

Many places filled with hills and uneven areas require even more expensive labor for laying pipes and sewage networks.

According to Casan’s director of expansion, Pedro Joel Hoffmann, complex systems cost an average of three times more to implement in hard-to-reach areas than in flat and structured areas, when equipment and labor costs are factored in.

“In more remote and sparsely populated areas, the cost of implementation is higher, and the payback period is longer,” he clarifies. In addition, the director draws attention to the difficulties in rebuilding and securing supplies in these places.

Casan invests in septic tanks in small municipalities

Kazan, which governs 194 municipalities in the state (of which 151 have a population of less than 25,000), faces a major challenge. Despite this, the company says it is confident in using the pits. “We repair septic tanks in houses, and Kazan operates a machine to clean cesspools,” he explains.

Another solution is to use a joint treatment plant. “We have started a pilot project in the municipality of Descanso in the west. There are 7 municipalities in this region, today they are all collected and processed at one station in Descanso,” explains Roberta Maas.

The use of the pit depends on the regularization

In the state’s smallest city, Santiago do Sul in the west, septic tanks are also being planned. “The municipal plan has yearly targets,” says Thiago de Paris, agrotechnician and municipal agreement manager in a municipality that has required a regular septic tank in new builds since 2017.

In older buildings, according to Thiago, there are often inadequate systems. “This is just a cesspool, which is not true. The municipality will be involved in installing filters and adapting the system. You must make a collection every 6 months and indicate the final destination, ”he concludes.

According to Rubens Filho, a researcher at the Trata Brasil Institute, the use of ordered pits in these cases is a favorable step forward. “The pit isn’t a problem if it’s done right. There are rules, engineering standards that you must follow. It can be beneficial if done right.”