Nadarzyn is a town situated approximately 30 km south of the capital city of Poland, Warsaw. The town and the surrounding area is flat with Nadarzyn itself being sparsely populated with houses and local amenities widely spread.

The water table is only approximately 1m below the existing ground level and trial holes found the soil conditions to be very poor. With these challenging ground conditions and the cost implications associated with installing a conventional gravity system it became apparent that an alternative sewer solution would be needed. ISA POLSKA Sp. z.o.o. met the challenge by designing a vacuum sewerage system which vastly reduced the construction period and the project’s capital costs.

With sewer and chamber depths being considerably reduced, a 35% capital cost saving was passed onto the client and the single vacuum station significantly reduce the operation and maintenance costs of the local water company.

Vacuum Pipework
The polyethylene pipework in sizes ranging from Ø90mm to Ø280mm.

Two submersible discharge pumps each rated at 20 l/s.

Steel cylindrical 16m³ vacuum vessel, vertically mounted underground on a concrete base.

Fully automated motor control centre is uses a programmable PLC to control the operation of vacuum and discharge pumps.

The valve monitoring console is situated alongside the MCC and monitors the open/closed mode of each interface valve located around the town.

Exhaust gases are filtered by passing them through a biological filter located outside the vacuum station building.

Vacuum Station Equipment
Three vacuum pumps manufactured by Busch each with a capacity of 630m³/hr.

The sewage discharge pumps installed in the Gorefield vacuum station are centrifugal screw-type pumps rated at 17l/s supplied by Hidrostal Ltd.

The vacuum vessel is fully coated inside and out as well as being certified to Lloyds standards. The motor control centre is fully automatic with PLC logic control. All pumps start in rotation and all conditions are monitored with a data logging system.

A PC based valve monitoring console was designed to allow comprehensive interrogation of each individual vacuum interface valve. This data provides quick and easy identification of potential problems long before it could lead to a line failure.

Summary
The ‘Vacuum Way’ proved to be the ideal solution to overcome the engineering difficulties resulting from the difficult ground conditions and offered a 35% capital cost saving to the client while minimising the operational cost for the local water company.

Possible Applications for Iseki Redivac’s Vacuum Technology
Rural community sewerage schemes
Industrial developments
Supply bases
Housing developments / compounds
Hazardous waste collection
Airports & military installations
Beach developments
Remote villages
Roof Drainage