Both schools are located at the coast in the west of Finland. Up here, in this beautiful nature area, the temperature can remain well below the freezing point for a few months in a row. Snow on trees gives incredibly beautiful winter scenes. In winter the sun dips below the horizon early in the evening – it is dark at 04.00 PM - and doesn't rise again until late in the morning the next day, so daytime is brief.
The previous treatment plant was a simple septic tank coupled with a drainage system that had reached the end of its operational life.
A new wastewater treatment plant was needed to provide reliable treatment for pupils and teachers, all together with a population equivalent of approximately 100 people.
As the sewage treatment site was close to the school and playground it was important to design a replacement septic system that would ensure no noise or odor. Another challenge was the discharge of the treated water: as the rear garden was sloping heavily down to the school and with heavy clay subsoils, a soakaway was not a viable solution.
On top of this, the selected septic system had to be chosen to cope with the very cold local winters and high seasonality of the wastewater flow, the school being unattended during weekends and holiday periods.
After discussion with our client, it appeared that the BIOROCK septic system would best suit the requirements of this site. The BIOROCK package sewage treatment plant is ideally suited to installation in tight spaces.
The existing septic tank was emptied and cleaned to be kept as the primary treatment. This septic tank is now followed by a BIOROCK-E septic system (now ECOROCK-3000). Treated effluent is discharged to a nearby stream.
Installation of the new wastewater treatment system was carried out in 2014 and took two days.
The extension of this school required selection, design, and installation of a brand new decentralized wastewater treatment system.
As there was no viable location for a soakaway, the preferred solution was to install a small-scale wastewater treatment plant. Because all drainage for the school and its facilities were located in an elevated garden behind the school, the main questions were: 1) Where to install the wastewater treatment plant? and 2) Where to discharge the treated effluent water?
BIOROCK won both the trust of the decision-makers and the project. A complete BIOROCK non-electric wastewater treatment plant was lifted on-site by a small excavator before being installed next to the car parking space in front of the school adjacent to the road.
The treated effluent is flowing down the slope next to the parking to reach a ditch in an adjacent farmer’s field (“gravity discharge” with no use of any pump)
With a very small footprint and the ability to work without any power supply, the BIOROCK wastewater treatment solution was the perfect septic system for this specific site. The selected wastewater system is composed of an ST-1-5000 BIOROCK Primary tank followed by an ECOROCK-3000 treatment unit.