Measures against water pollution in industries which perform metal finishing.

Effective legislation is the main driving force in controlling pollution and, indirectly in economizing in the use of water in industry. The control is exercised by municipal authorities over the discharge of waste water to public sewers or of river agencies that determine the quality of discharges to rivers. Important factors in the reduction of pollution in the metal finishing industries are factory lay-out; co-operation with local authorities so that the effect of any alterations in processing can be studied before treatment plant is installed; rationalization of factories; pretreatment enabling water to be re-used; and thorough survey of all water-using operations to make sure that any water used is essential for the success of the process. The most important factor in the economy of water and the prevention of wastage of raw and finished materials in the metal finishing industries has been the need of manufacturers to comply with pollution control legislation. Although enlightened manufacturers now see the financial benefits that may spring from the introduction of measures that lead to economies in the use of water and consequently may lead them to adopt such measures voluntarily, this has not always been the case. In fact it does not date back more than 10 or 15 years. And in areas where water is cheap and plentiful and the manufacturer meets with no resistance in disposing of his process wastewaters into public sewers or rivers or estuaries, practices which are prohibited in an increasing number of urban areas still continue. The main driving force in water economy is thus effective legislation that is enforceable and that is within the ability of industry to comply with if steps that are reasonable, practicable and not unduly costly are taken. Although the subject of legislation and administrative control is outside the scope of this conference its universal importance to manufacturer and individual justifies a passing reference to the need for pollution control, insofar as it necessitates the installation of treatment plant or hydraulic control measures on industrial effluents. Agencies created for pollution control of water courses must obviously be responsible for determining the quality of all effluents that are discharged into the receiving water. Likewise, any municipalities that receive industrial waste water must be given the powers to