Sem Timeline

Petrópolis was the first city in the state of Rio de Janeiro to grant private companies the concession to provide water and wastewater treatment services. Águas do Imperador was given the concession on January 1, 1998.

At that time, there was no wastewater treatment and only 2% of the population received chlorinated-only water.

Today, 95% of the locals have access to treated water, and 84% of the wastewater is treated, so the city now stands out among most Brazilian cities.

To date, seven water treatment plants have been built. Taken together, they treat about 61,8 million liters per day, and twenty-seven wastewater treatment plants process 56,2 million liters per day. The goal is to universalize wastewater treatment in the coming years.

Águas do Imperador also does an important socio-environmental work with its biodigester project in impoverished areas. The project has become an international reference. In the biogigesters, all organic matter found in wastewater is converted into methane gas, which is used in cooking stoves and generators. Biogas is offered free-of-charge to households, day care centers and other institutions. The biodigesters do not consume power and use recyclable material such as PET bottles in their filters.

  • City: Petrópolis (Rio de Janeiro)
  • Population: 282,500 inhabitants
  • Water treatment plants: 7
  • Water connections: 58,472
  • Number of units with water connection: 79,868
  • Wastewater treatment plants: 25
  • Sewer connections: 47,768
  • Number of units with sewage connection: 69,242


On January 1, 1998, Águas do Imperador started sanitation operations in Petrópolis. The first step was to increase the water catchment flow from 300 to 600 liters per second in the rivers Caxambu Grande and Caxambu Pequeno. An additional water supply piping system was laid and obsolete pipelines were replaced. The WTP Montevideo was built, and about 90,000 inhabitants started to get treated water. The WTP Itaipava, which did water chlorination only, was adjusted to do full treatment. The client database was fully updated and water meters were installed. Besides that, a personalized customer service was put in place.


The utility built the Ponte de Ferro Pumping Station and the Vargem Grande/Mosela water main. Upgrades to the 2-million-liter capacity Moinho Preto reservoir began, as well as works to implement a catchment facility and lay a water main at the Taquaril river. The Água do Taquaril Water Treatment Plant has started being built. The Palatinato Wastewater Treatment Plant gets under construction. In March 1999, the Environmental Education Program in partnership with the Education Department was kicked off. In the same year, simultaneous reading of water meters was implemented.


Águas do Imperador started up the Taquaril and Mosela WTPs and the Palatinato WWTP. The Moinho Preto Reservoir was completed and the Rio de Cidade dam works started. The company laid 37 km of water supply pipelines in the districts and suburbs Estrada da Saudade, Valparaíso, Duarte da Silveira, Cascatinha, Mosela, Floresta and Centro; and 10 km of wastewater pipelines in Centro, Quitandinha and Morin. The award “O Papel da Água” (The Role of Water) was launched for students enrolled in the company’s Environmental Education Program.


The Rio da Cidade dam and pumping station, which expands the Mosela WTP operations, was finished. The utility started building the Ferreira Well water main to increase production in the districts. Eleven kilometers of water supply pipelines were laid in the suburbs Bingen, Duarte da Silveira, Quitandinha, Valparaíso, Mosela, Vila Ipanema and in the city center; and 2,5 km of wastewater pipelines in the districts Morin, Quitandinha, Alto da Serra, Vila Felipe, Bataillard and Centro. The Águas do Imperador Laboratory is the only one in the mountains accredited by Inea to run 27 types of tests.


Águas do Imperador started building the Mosela/Valparaíso Water Main, the Ferreira and Mata Porcos dams in Correas, and set up the Bonfim WTP and the Granja Brasil, Taquara and Valparaiso WWTPs. Twenty-one kilometers of water supply pipelines were laid in Valparaíso, Retiro, Caxambu, Mosela, Parque São Vicente, Quitandinha, Morin, Centro, Pedro do Rio, Taquara, Saldanha Marinho, Roseiral, and in the districts. Also, 2 km of sewer pipelines were laid in Caxambu, Retiro, Independência, Taquara, Siméria, Morin, Estrada da Saudade and Granja Brasil. The Environmental Education Program was extended to the Palatinato WWTP. In that year, the “Wastewater Treatment and Protection of Nature” award was created.


The Mosela/Valparaíso water main was completed. In that year, the first biodigester, in Alto Independência, was started. Twelve kilometers of water supply pipelines were laid in Simeria, Vila Ipanema, Valparaiso, Mosela, Mauá, Bataillard, Jardim Salvador, Retiro, Bingen, Correas and Centro; and 7,5 km of sewer pipelines in Centro, Floresta, Quitandinha, Estrada da Saudade and Alto da Serra.


Beginning of construction to collect wastewater from the Historic Town. Wastewater is now treated at the Palatinato WWTP. The utility built the Historic Town Pumping Station and started up the Bonfim biodigester. Águas do Imperador laid 20 km of pipelines in Alto Siméria, Centro, Morin, Quitandinha, Capitão Paladini, Calembe, Coronel Veiga, Estrada da Saudade, Parque São Vicente, Granja Cláudia, Barra Mansa, Valparaíso, Madame Machado, Boa Vista, Vital Brasil, Olga Castrioto, BR 040, Ponte Branca, São Sebastião, Nogueira and Bingen; and 5 km of sewer pipes in Centro, Sertão do Carangola, Granja Cláudia, Granja Brasil, Bonfim, Pedras Brancas, Morin, Samambaia, Bairro Mauá and Quitandinha. The Water Quality Seal was launched.


The Itaipava WTP was expanded and its production jumped from 15 l/s to 50 l/s. The Pedro do Rio WTP and the Rodoviária WWTP were built. The company laid 22,5 km of water supply pipelines in Quitandinha, Independência, União e Indústria, Morro da Lenha, Retiro, Samambaia, Posse, Roseiral, Nogueira, Estrada das Arcas, Henrique Raffard, São Sebastião, Serra Morena, Sítio da Ponte, and Vale do Barã. Two kilometers of sewer pipes were laid in Nogueira, Correas, Centro, Quitandinha, Retiro, Secretário, Barão do Rio Branco, União e Indústria, Vila Constância, Madame Machado Bonfim and Valparaíso. In that year, Águas do Imperador participated in the 1st Book Fair of Petrópolis. The workforce training Classe Anexa Project started.


Águas do Imperador kicked off the Quitandinha WWTP construction works and interconnections of the Historic Town to the Palatinato WWTP. The Praça da Liberdade and Rua Padre Siqueira wastewater pumping stations were built and the Siméria biodigester was started up. Twenty-two kilometers of water supply pipelines were laid in Itaipava, Pedro do Rio, Secretário, Independência, Taquara, Sítio da Ponte, Henrique Raffard, Olga Castrioto, Pedras Bancas, Barra Mansa, Lajinha and Centro. The company also laid 2 Km of sewer pipes in the same locations. In that year, an agreement was signed between Águas do Imperador, the Petrópolis government, Inea and Ceivap, for the construction of ten biodigesters. Águas do Imperador ranked first place in the Private Company category of the 5th Furnas OURO AZUL Award. Reforestation efforts were started in the Maria Comprida and Capim Roxo river banks.


The utility started up the Quitandinha WWTP, the Nogueira biodigester and the Bonfim reservoir WTP, with capacity of one million liters. Besides, 9 km of water supply pipelines were laid in Cascatinha, Centro, São Sebastião, Comunidade vitória, Quarteirão Brasileiro, Morin, Alto Independência, Bingen, Mosela, Fazenda Inglesa, Barra mansa, Bonfim, Alto da serra, Samambaia, Pedro do Rio, Itaipava, João Xavier, Barra Mansa, Correas, Madame Machado, and Posse; and 2 km of sewer pipes in Centro, Nogueira, Valparaíso, Mosela, Bairro Castrioto, Roseiral, Fazenda Inglesa, Comunidade Vitória, Duarte da Silveira, Carangola, Estrada União e Indústria and Castelo São Manoel. The company participated, with the community, schools and the Environment Department, in the Second Reforestation of the Taquaril River banks.


The biodigester of Vila Ipanema was put into operation. Twenty-seven kilometers of water supply pipelines were laid in Águas Lindas, Atílio Maroti, Quarteirão Brasileiro, Siméria, Sertão do Carangola, Morro Florido, Morro do Neylor, Morro do Alemão, Retiro, Bingen, Samambaia, Pedro do Rio, Quitandinha, Fazenda Inglesa, Duarte da Silveira e Capitão Paladini; and 2 km of sewer pipelines in Vila Ipanema, Vila Constância, Sítio do Pica Pau, Morin, 24 de Maio, Itaipava, Duarte da Silveira, Centro, União e Indústria, Baitallard, Independência, Vital Brasil, Bingen, Taquara, Calembe, Ponte de Ferro, Sargento Boening.


The company started up the Secretário WTP and renovated the Pedro do Rio WTP. The Unimed WWTP was built and the Granja Brasil WWTP was expanded. The projects Viva Água, a touring service that reaches out to the communities to help locals sort out their issues, and Clientes de Valor, which targets old clients whose water connections have been terminated, were created. Laying and replacement of 17,5 km of water pipelines in Saudade, Castelânea, Morin, Quarteirão Ingelhein, Valparaíso, Castelo São Manoel, Capela, Siméria, Quitandinha, Itamarati, Coronel Veiga; and another 6 km in Corrêas, Pedro do Rio, Itaipava, Centro, Alto da Serra, Valparaíso, Posse, Secretário and Quitandinha. Laying of 3.5 km of sewer pipelines in Itaipava, Roseiral, Mosela, Vila Constância, Centro, Floresta, São Sebastião, Nogueira, Bingen, Alto da Serra, Caxambu, Itamarati, Bela vista, Castelo São Manoel, Pedro do Rio and Quitandinha.


Major achievements in the water supply system include the laying of about 13 km of water pipelines, replacement of more than 4.5 km of obsolete pipes and implementation of 13 new boosters. Seven kilometers of sewer interceptors were laid in the Quitandinha River Basin, and sewer pipes were extended or replaced in several districts of the city. The whole sewer system at the Historic Town, in addition to the Palatinato WWTP, Quitandinha WTP and some biodigesters underwent preventive maintenance. In October, the Piabanha WWTP constructions began.


Laying of over 22 km of water supply pipelines, of which 16 km were expansion lines, benefiting around 16,000 inhabitants in the region. Another 6 km were laid to replace obsolete lines. The Itaipava water supply pipelines were interconnected with the Pedro do Rio ones. Águas do Imperador also added another 6 km of sewer pipelines, which benefited 14,000 residents, and replaced 1.3 km worth of pipes.  The Taquaril, Itaipava and Mosela WTPs underwent improvements to increase production capacity and qualify the operations at these water treatment plants.
The Operational Control Center had its capacity to monitor and control the water production/distribution systems and wastewater pumping stations increased by three-fold. The control center monitoring points went from 15 to 48, also reaching the districts.


Some important sewer system expansion works were carried out in Petrópolis in 2012. In April, the Posse WWTP was started up to treat 900,000 liters of wastewater per day, generated by 7,500 residents of Posse; in July, the Piabanha WWTP started operations — it is a different plant, with a bioarchitectural design, sustainable solutions and high technology — to treat 11 million liters of wastewater per day, generated by 30,000 inhabitants of Mosela and Bingen. The company also started the Córrego Grande Biodigester in Posse, to benefit 1,500 people. With these new units, the percentage of urban wastewater treated in Petrópolis rose from 64% to 77%, one of the highest levels in Brazil.

The company also implemented and replaced 16,5 km of supply pipelines and 8 km of sewer pipelines.

The new Águas do Imperador store, a large, modern and finely located facility, was opened to better receive the clients.


As in the other years, Águas do Imperador maintained the same pace and commitment to do works for the improvement of sanitation services in Petrópolis in 2013. More than 21 km of water supply pipelines and 4,5 km of sewer pipes were laid. Besides, 4 km of water pipelines and 500 meters of sewer pipelines were replaced.

The company’s seventh biodigester, the Vila Rica Biogester, came into operation in July. The unit treats 130,000 liters of wastewater per day and benefits 2,000 local residents. The biogas generated by the biodigester is sent to the Santa Edwiges day care center, located right next to the unit.

The company interconnected most of the six main water supply systems (Centro, Mosela, Bonfim, Itaipava, Pedro do Rio and Posse), allowing the water produced in any of the systems to be sent to wherever there is immediate demand.

This massive amount of investments raised Petrópolis to the status of third city in the state of Rio in wastewater treatment and the 27th in Brazil, as reported by Instituto Trata Brasil, with 80% of urban wastewater treatment, meaning a total of 52.5 million liters of wastewater treated per day. Regarding water supply, 91.3% of locals are supplied with treated water, totaling 61.8 million liters of water per day.


Two new wastewater treatment plants — the Corrêas WWTP, which treats 1.2 million liters/day and benefits 15,000 residents of Corrêas and the surrounding areas — and the Quarteirão Brasileiro Biodigester, which treats 160,000 liters/day and benefits 2,000 locals, were built.

A 51.5 km stretch of pipelines was laid: 32 km of water supply pipelines in 25 suburbs and 10.5 km of wastewater collection pipes in 21 suburbs. Besides, 4.5 km of water supply pipes and another 4.5 km of sewer pipes were replaced.

The hydraulic modeling project was expanded to the districts’ supply systems, making it possible to obtain information in real time through a specific software application.

The company was a finalist of the ANA 2014 Award, in the Companies category, with the project “Sustainable Sanitation — The use of Biosystems and Environmental Education in Low Income Communities.”

A customer service center was opened in Itaipava.


Águas do Imperador laid 33 km of water supply pipelines and 5 km of sewer pipes in 39 suburbs, adding 6,000 new connections to the system. To handle the new connections, 10 boosters were built.

The Mosela WTP reservoir, with capacity for 1 million liters, was fully renovated.

The Montevideo and Mosela WTP treatment systems were fully automated. Works to the Caxambu and Morro do Gavião biodigesters were started.

The company’s charity programs were expanded.


The Caxambu and Morro do Gavião biodigesters were started.

The utility laid 34 km of water supply pipelines, 4 km of collection pipelines, and 13 boosters, to handle another 4,000 connections in 43 suburbs.

A reservoir was built in the Municipal Park of Itaipava, with a 500,000-liter storage capacity.

The Araras WTP project was started this year, along with its water catchment license.


In 2017, 20 km of pipelines were laid and 10 boosters were built to ensure the supply of 3,000 new water connections in 35 suburbs. Besides, 3 km of sewer pipes were laid.

In the districts of Posse and Nogueira, two wastewater pumping stations were built and the sewer pipes were improved and adjusted.

In June, Águas do Imperador won the Firjan Environmental Action Award 2017, with the project “Sustainable Sanitation: The Use of Biosystems and Environmental Education in Low-Income Communities.”

The Estrada das Arcas water main, of critical importance to water supply throughout the Itaipava region, started in November this year.

In 1998, the city had only one Water Treatment Plant, the Itaipava WTP, whose treatment was limited to the chlorination of water. At that time, only 2% of the population consumed treated water.

Today, seven plants are in operation: Montevideo, Mosela, Bonfim, Itaipava, Pedro do Rio, Secretário and Taquaril, which treat all the water distributed by the company — according to the World Health Organization standards.?

Together, the WTPs produce 61.8 million liters per day to guarantee water supply to 95% of the population.

Mosela WTP

  • Located in: Mosela
  • Treatment Capacity: 350 l/s
  • Population served: 114,000 people
  • Suburbs served:  Mosela, Bingen, Valparaíso, Coronel Veiga, Saldanha Marinho, Siméria, São Sebastião, Castelânea, and Quitandinha.
  • Treatment Type: Contact clarifier, filtration and disinfection.
  • Water catchment: Vargem Grande (Quilombos da Direita e Esquerda) and Rio da Cidade.

Montevideo WTP

  • Located in: Caxambu
  • Treatment Capacity: 300 l/s
  • Population served: 117,000 people
  • Suburbs served:  Centro, Alto da Serra, Morin, Quissamã, Itamarati, Estrada da Saudade, Castrioto, Boa Vista, Quarteirão Brasileiro and Retiro.
  • Treatment Type: Contact clarifier, filtration and disinfection.
  • Water catchment: Caxambu Grande, Caxambu Pequeno and Ponte de Ferro.

Bonfim WTP

  • Located in: Bonfim
  • Treatment Capacity: 100 l/s
  • Population served: 26,000 people
  • Suburbs served:  Corrêas, Nogueira, Samambaia, Jardim Salvador, Roseiral and Glória.
  • Treatment Type: Contact clarifier (self-cleaning airlift system), filtration, disinfection, sludge drying bed.
  • Water catchment: Pinheiral and Mata Porcos

Itaipava WTP

  • Located in: Itaipava
  • Treatment Capacity: 50 l/s
  • Population served: 7,000 people
  • Suburbs served:  Itaipava
  • Type of treatment: flocculation, settling, filtration and disinfection.
  • Water catchment: Santo Antônio

Pedro do Rio WTP

  • Located in: Retiro das Pedras
  • Treatment Capacity: 20 l/s
  • Population served: 12,000 people
  • Suburbs served: Pedro do Rio
  • Treatment Type: flocculation, settling, filtration and disinfection.
  • Water catchment: Retiro das Pedras

Secretário WTP

  • Located in: Secretário
  • Treatment Capacity: 10 l/s
  • Population served: 2,000 people
  • Suburbs served:  Secretário
  • Type of treatment: contact clarifier, filtration, disinfection, sludge treatment.
  • Water catchment: Maria Comprida

Taquaril WTP

  • Located in: Posse
  • Treatment Capacity: 20 l/s
  • Population served: 5,000 people
  • Suburbs served: Posse
  • Treatment Type: flocculation, settling, filtration and disinfection.
  • Water catchment: Taquaril

The Petrópolis sewer system consists of four treatment plants: Palatinato WWTP, Quitandinha WWTP, Piabanha WWTP and Posse WWTP, and 12 other wastewater treatment units in different suburbs, ten biodigesters and a biosystem which, together, treat 83% of urban wastewater. This index brought Petrópolis up to the 2nd place in the state of Rio and 25th in Brazil in the ranking of the top sanitation companies, according to Instituto Trata Brasil.

Quitandinha WWTP

  • Located in: Centro
  • Treatment Capacity: 243 l/s
  • Population served: 70,000 people
  • Suburbs served: Quitandinha, Coronel Veiga, São Sebastião, Siméria, Castelânea, Thouzet and Valparaíso
  • Treatment type: preliminary and secondary treatment (submerged aerated biofilters + high rate secondary settler + sludge thickener). Automated cycle.

Palatinato WWTP

  • Located in: Morin
  • Treatment Capacity: 160 l/s
  • Population served: 65,000 people
  • Suburbs served: Historic Town, Alto da Serra and Morin
  • Treatment type: primary and secondary treatment (screening + desander bay + upflow anaerobic reactor + biodrum tank + secondary settler + disinfection channel).

Piabanha WWTP

  • Located in: Centro
  • Treatment Capacity: 125 l/s
  • Population served: 30,000 people
  • Suburbs served: Mosela and Bingen
  • Treatment Type: preliminary treatment with waste, sand and fat separator; anoxic tanks; MBBR (Moving Bed Biofilm Reactor) tanks and settler.

Posse WWTP

  • Located in: Posse
  • Treatment Capacity: 10 l/s
  • Population served: 7,500 people
  • Suburbs served: Posse
  • Treatment Type: preliminary, anaerobic reactor, aerated biofilter and secondary settler.

Corrêas WWTP

  • Located in: Rua Manoel de Moraes – Corrêas
  • Treatment Capacity: 15 l/s
  • Population served: 9,000 people
  • Suburbs served: Praça de Corrêas, Bairro da Glória, Estrada Mineira, Hospital Alcides Carneiro and Castelo São Manoel, in the future.
  • Treatment Type’s + Aerated Biofilter + Settler