Kinh nghiệm của hầu hết các quốc gia áp dụng phí nước thải, ví dụ như Pháp, Đức, Italy và Trung và các nước Đông Âu, chỉ ra rằng chi phí được thiết lập dưới mức cần thiết để tạo ra gây ô nhiễm để giảm thải của họ, mặc dù họ nâng cao doanh thu cho mục đích kiểm soát ô nhiễm. | The experience of most of countries applying water effluent charges . France Germany Italy and Central and Eastern European countries indicates that charges are set far below the level required to induce polluters to reduce their discharges although they do raise revenue for pollution control purposes. By contrast in The Netherlands the water effluent charge which was designed as a tool for revenue raising only has also served as an incentive because of the high charge rates. The Netherlands also adopted the following approach to reduce the need for large amounts of information to assess the fees to be charged Households and small industrial polluters producing less than 10 pollution equivalents pe are not charged for the actual pollution they cause. Having relatively few opportunities to limit discharges this category of polluters is of minor importance to the instrument s regulating power. The great benefit is that this allows the executive bodies to reduce drastically the amount of information required. Fixed rates are used instead. Charges for medium-sized polluters 10-100 pe are not based on samples of their effluent but according to a coefficient table prepared by experts. This permits the probable amount of pollution to be estimated accurately for each branch of industry or sector on the basis of easily obtainable data such as the amount of water used by the production plant and the amount of raw materials it processes. Nonetheless the incentive to reduce pollution remains intact. Companies that believe they are overrated on the coefficient table can request their effluent to be sampled and then charged on the basis of the results Braceros and Schuddeboom 1994 . As demonstrated by effluent charge systems in numerous countries Box these systems are most successful when combined with regulation when applied to stationary pollution sources and when marginal abatement costs vary amongst polluters the wider the variation the greater the cost-saving .
