Individual industries will have to meet NEQS for their emissions (see Chapter 4. Emission requirements) with the development of primary treatment facilities. A site must be identified on the estate or on adjoining land which can treat combined sewerage discharges from all industrial estate users to an appropriate standard with a view also to the re-use of such water.
The estate must be designed with separate systems for stormwater and process water collection. Waste water minimisation techniques must be encouraged by the estate management to reduce impacts to receiving waters. This can include:
recycling of water from one process and one industry to another inside the estate;
using treated effluent as make-up water wherever possible;
design systems that recycle water repeatedly for the same purpose e.g. cooling
Contaminated liquid process wastes should be collected and treated separately from sewerage effluent.
Adequate solid waste disposal facilities must also be available to the estate users. If there are not proper solid waste disposal facilities close by a solid waste storage site must be provided on site. If industries producing hazardous waste are present, there must be arrangements for the handling and disposing of such waste.
Grouping of industries
The existing Provincial organisations responsible for the management of industrial estates already segregate industries according to pollution potential. Some existing estates were developed on the fringe of townships e.g. Peshawar industrial estate, but have subsequently been surrounded by urban expansion and residential areas. Many estates already discriminate against certain users. Some will not permit the development of industries producing chemicals and hazardous wastes. The Capital District does not allow any polluting industry in Islamabad. The National Reference Manual on Planning and Infrastructure Standards 1986 makes some recommendations with regard to a zoning of industrial estates according to different categories of industry (see 18.104.22.168 Zoning and Phasing in Appendix I of the NRMPIS).
The planning and design of the estate and its integrated sewerage treatment facility will be tied to the levels of liquid discharge which are acceptable. This will relate to the seasonal quantity and quality of receiving waters. Policies in regard to the grouping of industries must, however, be flexible according to the assimilative capacity of the receiving environment in terms of both liquid and atmospheric discharges. There may be sound reason to mix different types of industrial processes. Certain processes use large amounts of water which, with little if any treatment, can be reused in other processes. This is a matter of creative planning by industrial estate managers and plant designers to ensure the maximum use of water resources and the incorporation of waste minimisation techniques.
The following is a list of suggested criteria for development of industrial estates
no conversion permitted of forest land to non-forest activity to sustain individual industries,
sufficient space must be provided on site for the storage and disposal of solid waste and the treatment and reuse of wastewater,