The ACO Marine Clara waste water treatment plants suitable for water disposal from minor sources

The Clara waste water treatment plants process waste water from toilets, bathrooms, kitchens, washing machines and similar facilities.

Clara sewage treatment plants comply with all the requirements of EN 12566-3, which is proven by a CE certificate.

We guarantee the quality of our work. We are the only company on the market to offer a 10-year guarantee for static properties and water resistance of all our tanks. We trust the materials we use, and we are not ashamed to sign our name to our work.

Servac are an approved distributor for ACO Marine products

Aco marine logo


Applications up tu load class D 400
Easy installation with no additional concreting
Very stable and high treatment efficiency during irregular hydraulic and biological loads – overload-resistant
First-class electrical components
Effective purification
Low maintenance
Low energy consumption
Low costs for deep ground application
Odour-proof access cover with smart construction
High volume of storage tank

During the development of the Clara waste water treatment systems, great emphasis was placed on safe operation, easy cheap installation and easy maintenance. Thanks to this the Clara wastewater treatment plants rank among the best as regards system reliability and treatment efficiency.

Clara communal treatment plants are designed for larger sources of waste water that cannot be connected to public sewerage systems. This concerns especially Hotels, Holiday resorts, medium size and large companies, residential areas, gas stations and whole villages etc.

Clara treatment plants can satisfy everybody; demanding, environmentally friendly customers, building companies that demand easy and fast installation, or users themselves. All enjoy trouble free operation.

How The Clara Waste Water Treatment Process Works

Aco Clara Treatment Process


1 – pre-treatment
2 – buffer area
3 – storage part
4 – activation tank
5 – final sedimentation tank

Clara Treatment Process

  • Mechanical pre-treatment
  • Biological treatment by activated sludge
  • Final gravity sedimentation

Efficiency of purification

The following average values of effluents were achieved during tests in an accredited laboratory according to EN 12566-3:

BOD5………………………………………..6.7 mg/l
COD……………………………………….59.6 mg/
TSS…………………………………………6.1 mg/
lN-NH4……………………………………….2.0 mg/l

The Clara sewage treatment system plant consists of a mechanical pre-treatment and a biological compartment.

The mechanical pre-treatment part is formed of sedimentation tank with a high volume buffer area.

The sewage water enters the Clara unit via the Inlet pipe and flows in the buffer area of the storage tank. Settable solids fall to the bottom of the tank and floating matter is caught by a scum board, thus protecting the raw sewage air lift pump against blockage.

Hydraulic peaks at the inlet of the Clara sewage treatment plants are absorbed in the buffer area. The pre-treated water is the pumped at a uniform flow rate from the buffer area into the biological part of the plant. Hydraulic peak equalising considerably increases the stable purification efficiency.

The biological part of the Clara consists of an activation tank and a built in final sedimentation tank.

The activation tank is aerated by micro-bubble aeration.

The water goes from the activation tank into the final sedimentation tank

The water goes from the activation tank into the final sedimentation tank, which enables treated water to be separated gravitationally from activated sludge. The treated water flows out of the sewage treatment plant through the outlet connection. The activated sludge falls to the bottom of the final sedimentation tank, from where it is pumped back as return sludge and also partly into the storage area as surplus sludge.

The final sedimentation tank is optionally equipped with a skimmer for the automatic collection and removal of floating sludge from the water surface. This device can reduce maintenance work during operation. Surplus sludge is stored in the storage area, which in fully loaded plants is capable of holding about 100 – 150 days’ capacity. The pumping of sewage water and return and surplus sludge is achieved using air lifts in the Clara. These air lifts need no maintenance and are resistant to clogging. The hydraulic capacity of the air lifts is continuously adjustable, even at very low flow rates. This helps to ensure a uniform purification process and thus achieve stable purification efficiency.