Introduction

In 1990, the agriculture cooperative of our town, Barcs decided to build a new dairy factory outside of the town, about 3 km far from the centre on its own agricultural area. The older one which had got only 15 employees became small and was not able to satisfy the increasing demand of the town.

However, the company had to face a serious problem: the local Water and Sewer Company refused to accept the wastewater of the dairy production in the early stage of the design. So, it was evident that the dairy company needed an own private wastewater treatment plant. Since there was enough land around the factory they decided to construct a natural treatment system of slow rate using shallow trenches between the rows of hybrid poplar trees. After having accepted this plan by the authorities in the fall of 1990, an area of 10 ha was planted with poplar seedlings. I became familiar with this plant that time because the American Land-O-Lakes company gave some advice in connection with the natural treatment systems and I was asked to translate and adopt the American ideas into the local situation. Unfortunately almost nothing turned into reality from these ideas.

The new factory called Dráva Tej kft (Dráva Milk Co.) started its operation in the middle of 1991 with 55 people. At present 96 people are employed and they process about 60.000 litres of milk per day. The company produces about 20 different dairy products.

Environmental problems

In January 1991, the Regional Environmental Authority drilled a groundwater monitoring well (No.1) and measured some parameters of the groundwater to get data of the original situation. When the production started in the factory and wastewater was released to the treatment plant the authority measured monthly the quality of the groundwater for one year. As everything seemed to be perfect in July 1992 these control measurements were stopped.

Next time (in April 1993), when the authority measured again the groundwater parameters contamination was realized. Unfortunately the situation became very serious by September. (See the graphs.) Therefore the Regional Environmental Authority stopped the operation of the natural treatment plant and wanted to fine the company. Finally, the dairy company got a six-month permisson for storing the produced wastewater in temporary reservoirs and during this period it had to prepare a study on further operation of the treatment plant or an other solution for handling the wastewaters.

When the director of the dairy company, Mrs Rezsõ Francz learned that our school changed a little its profile in September 1993, and started to train environmental technicians she - remembering of me - contacted us to get some help. Being a company which really wanted to take care of its environment she expressed her maximal support in oder to find a final solution for this problem.

We have realized that the solution of the problem would take a lot of time, maybe years, so we thought that this investigation and the later operation and monitoring of the treatment plant could be fitted into the curriculum of the school. The students of environmental department could could measure the quality of wastewater produced by the company and the quality of the groundwater. The forestry students could take care of the poplar seedlings and control the growth of the poplar trees.

Having discussed this idea we offered the following to the dairy company: we try to find some solution for the most urgent problems in exchange for monitoring the operation of the natural treatment system as a part of our practical trainning. It would mean that our students could have free access to the treatmant plant. Mrs Francz liked very much this idea and we made a written contract which was sent to the Environmental Authority as a sign of goodwill of the dairy company. Fortunately the Environmental Authority accepted this contract and gave us six month to improve the operation of the treatment plant (deadline was June 1, 1994). We agreed that we'll measure the groundwater parameters with the schools's Merck SQ 118 photometer with cell tests provided by the diary company. In addition, the company bought for us a TR 205 Thermoreactor for measuring COD.

Action taking

That time a student of Technisch Lyceum Eindhoven (our Dutch sisterschool), Karen Braat studied at our school. When his teacher and our school's environmental education advisor, Mr Jef van den Hurk visited her we mentioned this project to him. He liked this idea very much and with his help we started a thorough investigation of the working processes in the company.

The first step was that the company started to use phosphate-free detergents. In addition, they bought a new washing system working with hot water and recirculation in order to produce less wastewater.

After studying the flow of wastes in the company we came to the conclusion that the groundwater pollution was mainly due to one thing: the unused milk and whey, and the expired milk, delivered back from the shops, were simply released to the treatment plant.

Of course, the solution was quite easy: these wastes had to be recycled. The company itself found a farm that wanted to use these wastes for feeding animals. In the beginning this "waste" was absolute free but know the company has a quite big profit from selling them to the farmers.

In April 1994, during the field practice lessons we bored six groundwater monitoring wells in order to determine the orientation of groundwater movements and the spreading of contamination. After some measurements we had to realise that the movement of groundwater and pollution took place in the direction of monitoring well No.1. So, the assumption of Environmental Authority that the groundwater moved towards the Dráva River was correct. Therefore we discussed with the dairy company and the authority to measure continuously only the well No.1.

After these preliminary operations the temporary loading of the trenches under the control of the Environmental Authority started again in June. We had to realise that there was nobody responsible for the operation and maintenance of the plant. The trenches were accidently filled up through the manually operated distribution system; some of them were overflooded. Since the poplar trees were (and they still are) so young, the uniform distribution of the wastewater is a crucial point of operation. We suggested to appoint somebody as an operator of the treatment system. It was very interesting for our students to see the importance of such a position in the real life.

After a few months we had to realize that the groundwater level highly fluctuates. When we bored the wells in April the average level was -80 cm but it decreased to -2.00 m. Since nobody recorded these values before, we were not able to find correlation beteween the groundwater quality and level. (In January 1995 we started to monitor this relationship.) Therefore we suggested to the company to use the emergency reservoirs in case of high groundwater level and to relaese the wastewater gradually into the trenches.

The result

It can be seen on the graphs that the quality of groundwater dramatically improved: some parameters has reached the original level. In December 1994, the Environmental Authority, checking our results and seeing the positive attitude of the dairy company, gave an official permission to operate again the natural treatment system. However, this permission stipulates that the company has to have the monitoring well No.1 measured every month and the results have to be sent to the Authority. They agreed that our school could continue these measurements.

In April, 1996, Jef van den Hurk organized a course for the teachers of the Hungarian environmental secondary schools in the Dráva Tej Co. The main topic of this course was how the practical environmental protection as a project education method can be built into the Hungarian curriculum. The cooperation of the dairy company and our school was a good example how a company can take care of its environment with the help of a school and how this cooperation can be built into the curriculum. This cooperation is profitable not only for the company and the school but for the whole community.