An important part of the economic and social development of any country is the construction sector. There are major challenges in all phases of projects, in both civil engineering and in building, to minimise the impact on people and the environment.

In the developed world, environmental issues such as the efficient use of resources and their sustainability, the protection of biodiversity, climate change and the risk of accidents have become very important in all areas, including construction.

In Europe, the Environmental Impact Assessment Directive 2014/52/EU establishes the legal framework to ensure a high level of protection for human health and the environment by establishing minimum levels for the environmental impact assessment of projects.


A project is understood as a construction or other installations and works, including those devoted to the exploitation of mineral resources. Both public and private projects are subject to a process of Environmental Impact Assessment (EIA) and an obligation to establish an Environmental Management Plan (EMP), which is a tool accompanying the project at all stages of design, implementation and monitoring.

An important part of the Environmental Impact Assessment of a construction project, especially in civil engineering, is water management.

Water is a key component of a construction project and is used as part of the fluid for excavation and foundations, as a means of cooling machines (e.g. tunnel boring machines, drilling rigs and cutting machines) and as a means of cleaning. In many cases, it also appears as a result of rain and effluent seepage. In any case, it must be properly managed to optimise its consumption and to ensure it does not harm the environment. There are national and local regulations in most countries establishing the properties of water being fed into a public effluent, which place limits on suspended solids (SS), acidity (pH), biological oxygen demand (BOD) and chemical oxygen demand (COD).

If these values show the water cannot be discharged into a public effluent, it is often stored in pools for natural evaporation of the water, with consequent problems of space and the risk of overflow. Other cases use traditional systems of physical and chemical treatment, which typically consist of a pH adjustment step by CO2, a coagulation-flocculation step using PACs and lamellar decantation. This type of treatment requires relatively complex equipment, lots of space for installation and the chemical additives necessary for the operation, which are difficult to store and handle. In addition, the sludge obtained must be treated and managed as waste.

To solve this problem, NIHON KASETSU has developed a simple and effective clarification system to treat construction wastewater.


It is based on using a single chemical additive powder, which acts as a coagulation-flocculation agent, which is largely insensitive to the water pH, so no adjustment is required in most cases. It is an inorganic chemical compound made from 100% natural substances, which are safe and non-polluting and are based on mollusc shells, seaweed and minerals. It is safe, easy to handle and contains no substances harmful to humans or the environment, so the final sludge can be deposited in landfill sites.

The whole clarification process is extremely efficient and is performed in a very compact machine (3.5 x 2 m only), with a large treatment capacity (up to 90 m3/h), and is very easy to transport, install and operate.


Please contact us for more information.