Cleaner Technology Projects in Denmark 1997

Environmental Management in a Local Government Activity – a Water Purifying Plant

Miljøstyring i en kommunal forsyningsvirksomhed - renseanlæg
Arbejdsrapport nr. 6, 1997, Miljøstyrelsen

With a view to minimising the resource consumption of Herning Centralrenseanlæg (Herning Purifying Plant) an environmental management system was developed. The system integrates and structures the environmental actions in accordance with current plans and demands in the field and supports the present work routines. This report describes the elements of the environmental management system and how the system was established. Furthermore, the environmental statement for 1994 is presented in the report. 

Environmental management in Herning Water Purifying Plant is a continuing process, which aims at combining the day-to-day operations with the management of the plant whereby the operational objectives (quantitative objectives) are directly implemented in the single operations. An important condition of a successful outcome is a process monitoring strategy for the plant, which makes it possible to treat all the environmental data from the purifying plant on a daily basis.

The Environmental Management covers nearly all aspects of the plant, including raw materials (waste water, chemicals, drinking water, energy), finished products (mud and cleaned waste water), residuals (sand, grease, ore ready for roasting, packaging) work environment and organisation.

The environmental management system contains the following elements:
A short description of the purifying plant and a review of the environmental aspects.
The formulation of a general environment policy with guidelines and operational objectives.
The design of an environmental management system which identifies fields of responsibility and environmental objectives.
The establishment of procedures and system checks for the optimising of the daily operations.
potential actions
The establishment of procedures and system checks for a yearly environmental statement.
The appointment of an accountant and the drawing up of procedures for the audit.

It is important to motivate and make use of the employees on all levels at the purifying plant. Meetings regarding employee participation are held approximately 10 times a year. In the report the division of work and the organisation chart are described. It is the responsibility of the operations manager to ensure that the environmental policy is respected through the delegation of responsibility and the determination and control of the general operational strategy.

At weekly meetings the operations manager follows up on central operation parameters. Dependent on the distance between the actual achievements and the operational objectives and the established requirements, adjustments of the strategy for single operations, the whole plant, or the operational objectives are made. Dependent on the difference between the operational objectives and the state of affairs, the external accountant is called in.

In the review of the environment a general survey of the consumption of water and recycling of the purifying plant’s chemical and energy consumption is made. In addition, the plant’s mud quality control, the residual control and how the residuals are discharged are reviewed. Moreover, the work environment of the plant is examined.

Proposals for water, energy and chemical minimising in the operations are presented together with the expected results of the environmental efforts. In addition, the work environment problems are described and, in this connection, proposals for the improvement of the work environment are given. After having reviewed the environmental statement, five main action areas were reached:
An expansion of the total hydraulic capacity of the post-clearing tanks in order to reduce the overflow in connection with the pre-clearing.
An improvement of the work environment in the central building edifice.
The final draining: A reduction of the impact on the work environment, a reduction of the polymer consumption and an increase of the dry matter content in the drained mud.
The establishment of digesting tanks, a gas generator and a gas engine.
Various modernisation and reconstruction of the plant

An important tool to see the broader perspective and to stimulate the motivation is information technology combined with training and techniques for measuring. In the recent years these three elements have been of high priority in Herning Water Purifying Plant. The process monitoring system DORA, which makes it possible to calculate mass balances and process key figures in combination with set points, has been introduced. The data is structured in the process reports, which gives an overview of the process with a view to evaluating, and hence, establishing a general operation strategy for the plant.

Once a year an environmental statement is made. The statement gives an account of the environmental actions that have been made in the course of the year and the results achieved in this connection. At the end of the report the purifying plant’s environmental statement for 1994 is presented.

Author/ institution

Claus Nickelsen, Vandkvalitetsinstituttet
Danisco Sugar

This report is subsidised by the National Council for Recycling and Cleaner Production 

ISSN no. 0908-9195
ISBN no. 87-7810-734-2