The initial phase of construction of the Matasnillo River Sanitation project in Panamá City, Panamá, was finished in January 2026. Once completed, the expanded wastewater treatment infrastructure will help the city noticeably reduce urban pollution in both the city’s main river and Panamá Bay. PENETRON ADMIX, a crystalline concrete waterproofing admixture, was added to the shotcrete mix to ensure durability and extend the service life of the new concrete structures.
With a population of around 1.1 million within the city and over 2.1 million living in the metropolitan area, Panamá City is easily the largest city in Panamá – as well as the country’s capital. A well-known hub of business and banking transactions, tourism, and trade, it has played a major role in the route of spices, silver, silk, porcelain and gold throughout the country’s history. Also, Panamá City’s key role in maritime trade is underlined by its location at the Pacific Ocean end of the Panama Canal.
“However, given the city’s overwhelming economic importance to the country and its growing urban population, it also faces notable challenges related to waste management and the degradation of Panamá Bay, which is currently considered in a eutrophic state, unfit for consumption or recreation,” explains L.E. Aura Varo C., Director of Ecogreen International, the Penetron representative for Panamá.
Recently launched, the Matasnillo River Sanitation project is part of a national government action plan to manage and eliminate urban waste that previously flowed into the Matasnillo River, the country’s most polluted river, which runs through the heart of the city before entering Panamá Bay and the Pacific Ocean.
“This is the first stage of an expanded sanitary sewer infrastructure that will enhance Panamá City’s wastewater collection and treatment capacity,” adds L.E. Aura Varo C. “Once the project is completed, it will enable a significant upgrade to the environmental quality of the Matasnillo River and the Bay of Panamá, as well as improve health conditions for the people living in the Panamá City metropolitan area.”
A key part of the Matasnillo River Sanitation project, the construction of the US$95 million Matasnillo River main collector project was financed by the Inter-American Development Bank (IADB). Construction work comprised new sanitary sewage pipes, storm water pipes, wastewater collection systems, wastewater interceptor systems and wastewater treatment plants. For example, the project’s central 7.55 km tunnel to intercept wastewater from existing systems and those previously discharged into the river now transports the wastewater to the Juan Diaz Wastewater Treatment Plant – which previously ended up in the Matasnillo River.
CEMEX Panamá, the project’s ready-mix concrete supplier, specified PENETRON ADMIX, a crystalline waterproofing admixture, to protect new concrete structures from constant exposure to the collected effluent and contaminated waters of Matasnillo River. The admixture was added to the shotcrete mix and applied to the pit structure surfaces of the wells for permanent protection against concrete deterioration. PENETRON ADMIX was used to treat over 3,800 m3 (4,970 yds3) of concrete for all the wastewater collection pits.
Once exposed to moisture, the active ingredients in PENETRON ADMIX generate a non-soluble crystalline formation throughout the pores and capillary tracts of the concrete. This permanently seals microcracks, pores and capillaries against the penetration of water or liquids from any direction.
“The construction of the inlet and outlet wells for the wastewater tunnels in Panamá City marks an important milestone on the road to cleaning-up the Matasnillo River – and Panamá Bay,” notes L.E. Aura Varo C. “This project has the potential to completely transform Panamá City!”
Cleaning up Panamá’s most polluted river: The new wastewater collection network and wastewater treatment plants now prevent urban waste from flowing untreated into the Matasnillo River.
