On 6 January 2016, the EPA announced revisions to six items in the Effluent Standards to reduce the risk of farmland becoming polluted. For enterprises or operators of sewer systems in specified effluent total quantity control areas, the maximum values of cadmium, total chromium, hexavalent chromium, copper, zinc and nickel in the effluent have been tightened. Currently, water quality of discharged effluent generally meets current control standards. However, its discharge into water bodies that have low base flows, such as irrigation ditches and some small waterways, may cause the accumulation of heavy metals and heighten the risk of contaminating irrigated farmland and agricultural produce. The EPA has thus tightened the maximum values for cadmium, total chromium, hexavalent chromium, copper, zinc and nickel in the effluent depending upon the category of specified effluent total quantity control zones. The new values will apply to effluents that will flow through water bodies in the total quantity control zones, announced by the local competent authorities for the protection of farmland. An effluent total quantity control zone is classified as Category 1 if the water quality of receiving water bodies in the area does not meet the quality standards for irrigation water. Once an area is announced as a Category 1 Effluent Total Quantity Control Zone, the establishment of new enterprises or sewer systems will not be allowed. For existing enterprises, the control values for cadmium, total chromium, hexavalent chromium, copper, zinc and nickel will be the same as the standards for irrigation water quality; for existing sewer systems, the control values for these six metals will be half of those of the current effluent standards. The less strict standards for sewer systems were set to encourage existing enterprises to relocate to industrial parks. An effluent total quantity control zone is classified as Category 2 if the water quality of receiving water bodies in the area does meet the quality standards for irrigation water. In a Category 2 Effluent Total Quantity Control Zone, the establishment of new enterprises or sewer systems will be allowed but with tightened effluent standards. The control values for cadmium, total chromium, hexavalent chromium, copper, zinc and nickel will be the same as the maximum values permitted under the current irrigation water quality standards. For new sewer systems, the control values for these six heavy metals will be half of the maximum values of the current effluent standards. For existing enterprises and existing sewer systems, the maximum values will also be cut to half of the current effluent standards. Several other standards have also been revised, including the Effluent Standards, the Chemical Industry Effluent Standards, the Petrochemical Industrial Parks Sewage System Effluent Standards, the Optoelectronic Materials and Component Manufacturer Effluent Standards, the Wafer and Semiconductor Industry Effluent Standards, and the Science Park Sewer Systems Effluent Standards. Effluent standards are a form of end-of-pipe control, and the EPA is urging all enterprises to ensure that wastewater treatment facilities are operated properly and at maximum efficiency. They should also strengthen source control during the manufacturing process over waste solvents to reduce the amount of chemicals that enter wastewater treatment facilities.