The industrial revolution increased the consumption of water and when combined with simple disposal of wastewater a major impact on the aquatic environment became apparent.

Towards the end of the nineteenth century experiments in the field of wastewater purification began, the primary concern being the physical appearance of the water with the activated sludge process being developed early in the twentieth century.

Whilst the volume of water being treated increased during the next 50 years the need to do more than basic treatment did not gain momentum in Europe until the 1970's and 80's.

In Europe demands for improvement resulted in the 1991 Urban Wastewater Directive, this directive laid down minimum standards for wastewater treatment. Further directives have addressed the levels of nutrients being discharged and the Water Framework Directive is further driving the need for high quality measurement and control in the treatment of wastewater.

Disposal of effluent is now controlled by law and can incur significant costs. The nature of the effluent will determine whether it can or should be discharged to the environment or to a sewerage company, while a more cost-effective alternative for some companies is treatment on site. The technical and legal implications of choosing the right options need careful evaluation.

Costs are determined and charged by the local water company responsible for waste water treatment and are based on a set formula using both the volume and the nature of the waste water from the factory that is discharged to drain.

Additional costs can be levied from the Environment Agency for breach of any consent limits. Companies who display responsibility in monitoring and managing their discharges are looked upon favourably by the authorities.